# clas a/b or d amp for subwoofer sq?



## comfy_shoes

hi there I was wondering if looking for sq out of your sub woofer....wether going with a a/b or d class amp will make much of an audible difference. I am considering a kicker amp . I am curious to know wether the a/b zx400.2 bridged in mono or the zx400.1 class d will be a better choice. is there a percievable sound quality difference from anyones experience?


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## 89grand

Use whatever you want. There's no audible difference in amplifier class, especially on subwoofers. In fact, use class D, it's more efficient anyway.


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## gitmobass

^^^x2 on what 89grand said, use class D, less alternator strain.


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## nitrofish72

I would go with a class a/b for a better damping factor. If your looking for something a 1000 watts or over then i would go with a class d because of a smaller footprint and less strain on your charging system.


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## comfy_shoes

whats damping factor? what does it do?


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## Mless5

I run old a/b and couldn't be happier. I loose that control and precision once I switch to D, it sounds like a different speaker/box altogether.


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## nitrofish72

In loudspeaker systems, the value of the damping factor between a particular loudspeaker and a particular amplifier describes the ability of the amplifier to control undesirable movement of the speaker cone near the resonant frequency of the speaker system. It is usually used in the context of low-frequency driver behavior, and especially so in the case of electrodynamic drivers, which use a magnetic motor to generate the forces which move the diaphragm. Hope this helps you out.


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## comfy_shoes

thanks everyone so far! I just need to convince myself on how much of an audible difference a class a/b over a d will sound. is it noticeable to a point that you can distinguish instruments better? and if so on a scale from 1-10 how much would you say the difference is......for example. how would the dynamics of a kick drum sound? thanks!


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## 89grand

A: No one could ever pick out which amplifier was playing on a subwoofer in any test. B: Damping factor in real world use means next to nothing. C: Use the most efficient amplifer you have...(hint, class D)


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## DarkScorpion

Go with a class D, like everyone says. They're smaller and more efficient. I'd worry more about your box design and subwoofer choice if you're so concerned with sound quality.


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## Catman

If you are into Boom and Doom ...then Class D ...if you are serious about SQ ....A/B is the only way to go. While it is not as noticeable on subs ...Class D amps are horribly noisy as well as having a poor damping factor.

>^..^<


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## 89grand

Catman said:


> If you are into Boom and Doom ...then Class D ...if you are serious about SQ ....A/B is the only way to go. While it is not as noticeable on subs ...Class D amps are horribly noisy as well as having a poor damping factor.
> 
> >^..^<


Really?

Please continue with more detail.


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## mikey7182

Catman said:


> If you are into Boom and Doom ...then Class D ...if you are serious about SQ ....A/B is the only way to go. While it is not as noticeable on subs ...Class D amps are horribly noisy as well as having a poor damping factor.
> 
> >^..^<


Can you have Boom and Doom, and a bit of SQ too? Maybe... BDSQ??


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## Catman

89grand said:


> Really?
> 
> Please continue with more detail.


Just because "YOU" can't hear it ...and don't want to believe it doesn't make it not true.

>^..^<


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## 14642

Signal to noise in a sub amp means next to nothing. Damping factor as a measure of cone control is complete BS, but efficiency isn't. There's nothing wrong with class-D, but there are crappy amps of all classes. Don't be fooled by snake-oil salesmen peddling nonsense for an arm and a leg. What does matter is power output, cost and reliability.


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## ghostmechanic

Andy Wehmeyer said:


> Signal to noise in a sub amp means next to nothing. Damping factor as a measure of cone control is complete BS, but efficiency isn't. There's nothing wrong with class-D, but there are crappy amps of all classes. Don't be fooled by snake-oil salesmen peddling nonsense for an arm and a leg. What does matter is power output, cost and reliability.


Yep. I've heard good & bad from either class. I've heard good & bad from different type of enclosures, i.e. sealed vs. ported vs. folded horn vs. whatever. 

If the enclosure is built well & the speaker is happy then it'll sound good(well placement helps as well). If the amp is built well then it'll "sound good". Class D is smaller, more efficient & also cheaper per watt. Just stick to a reputable company. 

My personal preference is class AB but I like "old school" amps. I like Made in USA & I like the fact that if it breaks it's actually worth rebuilding.


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## Indiansprings

Lets say this one more time.
You will NOT hear a differance. Class D is much more efficiant. Use whatever you want, but dont base you decision on weather its class A/B or class D. If anyone has any documentation proving otherwise, please produce it.


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## Vega-LE

Indiansprings said:


> Lets say this one more time.
> You will NOT hear a differance. Class D is much more efficiant. Use whatever you want, but dont base you decision on weather its class A/B or class D. If anyone has any documentation proving otherwise, please produce it.


Usually class D has more THD (.1% class D compared to .05% class A/B). I owned a class D once, sold it and will never go back. Yes, I can hear the difference. I'd only buy class D if space and or current draw would be an issue.


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## Indiansprings

Vega-LE said:


> Usually class D has more THD (.1% class D compared to .05% class A/B). I owned a class D once, sold it and will never go back. Yes, I can hear the difference. I'd only buy class D if space and or current draw would be an issue.


You could tell the differance between .1% and .05% THD? WOW!


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## Vega-LE

Indiansprings said:


> You could tell the differance between .1% and .05% THD? WOW!


I sold my amp for a reason, and I didn't regret it.


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## 94VG30DE

The install, sub, and enclosure is also going to determine a little bit to whether you are going to "hear" a difference between A/B and D on a sub amp, but I would say there is a 99% chance you should not spend one more second on this and just go class D. 
For what it's worth, I ran a Kicker ZX400.1 for a sub amp for a while and was very happy with it. I switched to matching Alpine amps, so I have no use for it anymore. It's for sale in the classifieds, and I am pretty flexible on that price if you want to take a look at it. 
http://www.diymobileaudio.com/forum...mp-alpine-mrp-t220-sony-xav-7w-brain-box.html 

But seriously $/watt I would definitely go class D for a sub amp. There's no reason not to over such a narrow passband.


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## ChrisB

I thought the true meaning of Damping Factor was that it was the amplifier's ability to deal with changes in impedance over distance? I know damping factor was real important when I used to DJ and speaker wire runs could be as long as 200 feet.

Also, if Damping Factor is so important, how come the real true audiophiles love those $6,000 tube amplifiers that have a single digit damping factor?


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## thehatedguy

Because they are usually not running amps with DF on low frequency speakers. And if they are, the speaker has an insanely low Q and provides a great deal of control on it's own.

I haven't been sold on class D yet either. I haven't heard many that sound like a good a/b.


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## smithee419

I'm not a big fan of class d amps either. But that's a personal preference of mine. Your gonna get mixed replies on this one, it will be a never ending battle!


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## Niebur3

I like when people make bold statements as "you will not hear a difference" and then ask for technical proof to the contrary. Wow! I say I can hear a difference between Class A/B and Class D and between different amp brands. I think some of this depends on the quality of speakers, enclosure and other factors, including quality of amplifier, etc. I'm sure you don't hear a difference between different Head Units and RCA cables. Well, then I guess some of us have more sensitive ears and/or our equipment has the ability to show these details. The real thing that needs to be addressed is the fact that comfy_shoes is asking about kicker amps. Concerning kicker, use whatever (class A/B or D) it won't matter. The newer kicker amps are all about power and noise, sq is not even in their vocabulary. If you are talking about the upper echelon of products, you will be able to hear a sq difference and I don't need to prove to you otherwise, just because you say you can't hear it.


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## Indiansprings

Niebur3 said:


> I like when people make bold statements as "you will not hear a difference" and then ask for technical proof to the contrary. Wow! I say I can hear a difference between Class A/B and Class D and between different amp brands. I think some of this depends on the quality of speakers, enclosure and other factors, including quality of amplifier, etc. I'm sure you don't hear a difference between different Head Units and RCA cables. Well, then I guess some of us have more sensitive ears and/or our equipment has the ability to show these details. The real thing that needs to be addressed is the fact that comfy_shoes is asking about kicker amps. Concerning kicker, use whatever (class A/B or D) it won't matter. The newer kicker amps are all about power and noise, sq is not even in their vocabulary. If you are talking about the upper echelon of products, you will be able to hear a sq difference and I don't need to prove to you otherwise, just because you say you can't hear it.


If two Identical setups were in front of you and one had the sub running on a class D amp and the other running on an A/B amp. You would not be able to tell me which one was which. Wouldnt you be interested in reading some technical proof one way or the other? It would be interesting to me. This thread will start going down hill soon.


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## t3sn4f2

Niebur3 said:


> I like when people make bold statements as "you will not hear a difference" and then ask for technical proof to the contrary. Wow! I say I can hear a difference between Class A/B and Class D and between different amp brands. I think some of this depends on the quality of speakers, enclosure *and other factors*, including quality of amplifier, etc. I'm sure you don't hear a difference between different Head Units and RCA cables. Well, then I guess some of us have more sensitive ears and/or our equipment has the ability to show these details. The real thing that needs to be addressed is the fact that comfy_shoes is asking about kicker amps. Concerning kicker, use whatever (class A/B or D) it won't matter. The newer kicker amps are all about power and noise, sq is not even in their vocabulary. If you are talking about the upper echelon of products, you will be able to hear a sq difference and I don't need to prove to you otherwise, just because you say you can't hear it.


Yup, there one other mayor factor. You knowing what amp you are listening too.

2:46 into the vid.

http://www.youtube.com/watch?v=8Zqe4ZV9LDs


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## ChrisB

I once played a trick on a friend of mine regarding his setup. He wanted to borrow one of my amps because he said his didn't sound right. He came over, I told him to make himself at home while I installed the new amp, and then I noticed that his gains were all the way down. I put them about where they should have been to begin, tested the system for about 10 minutes, then had him sit inside his car. He said "Wow, your amp sounds so much better than mine ever did and man did you ever swap them out FAST."

He felt dumb when I showed him that it was the same amp, just set properly.


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## Niebur3

Indiansprings said:


> If two Identical setups were in front of you and one had the sub running on a class D amp and the other running on an A/B amp. You would not be able to tell me which one was which. Wouldnt you be interested in reading some technical proof one way or the other? It would be interesting to me. This thread will start going down hill soon.


There is no technical proof unless you can tap into my brain some how...just like specs can't always tell the whole story about a speaker.



t3sn4f2 said:


> Yup, there one other mayor factor. You knowing what amp you are listening too.
> 
> 2:46 into the vid.
> 
> YouTube - Penn & Teller: ******** - Organic Taste Test


Are you kidding me, people trying to taste a difference between organic and non organic food. If we are going there....how about filtered water for that matter, say you can't tell a difference with that.



06BLMUSTANGGT said:


> I once played a trick on a friend of mine regarding his setup. He wanted to borrow one of my amps because he said his didn't sound right. He came over, I told him to make himself at home while I installed the new amp, and then I noticed that his gains were all the way down. I put them about where they should have been to begin, tested the system for about 10 minutes, then had him sit inside his car. He said "Wow, your amp sounds so much better than mine ever did and man did you ever swap them out FAST."
> 
> He felt dumb when I showed him that it was the same amp, just set properly.


I'm not dumb, I have done an AB comparison with amps, hu, speakers and eq, time alignment, crossover points, etc. When you hook 1 amp brand to 1 side and 1 amp brand to the other, match level and listen, there IS a difference. Same with HU, etc. I used to try to play that trick on my wife when tuning, just to see if she actually heard it and she was right every time, not almost every time, but EVERY time. I would say, there, how does that sound after NOT changing something in the back and she would simply say, "it sounds the same". You need not to only have a great overall system, but you need great hearing and a great memory. If you are playing a track for the 1st time, some may not hear a difference, but if you play something you know better than anything...then the difference is like a slap in the face.


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## Niebur3

Stephen Matz of Zed Audio has an entire paragraph talking about the issues with Class D design, referring to the reasons these amps having a history of sounding bad and being unreliable in the instruction manual for their new amps and further discusses how they were able to change reliability and bad sound with their new Class D amps. I'm sure if you email him, he will probably send you the technical proof you are looking for .

I'm not saying we can't get to the point where we can't hear a difference as long as we are talking the same brand, we just are not there yet and to me Class A/B, even on a sub, sounds much better.


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## Indiansprings

I think this new ICE class D is there now. This isnt the same as Class D, 2 years ago.


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## 89grand

I'll just say this. Many people claim to be able to hear the differences between amps, cables, power wire or whatever, yet not one single person has ever been able to prove it.

Weird huh?


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## t3sn4f2

89grand said:


> I'll just say this. Many people claim to be able to hear the differences between amps, cables, power wire or whatever, yet not one single person has ever been able to prove it.
> 
> Weird huh?


Emotion (ie subconscious pride) trumps logic every time.


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## 89grand

I like Coke better then Pepsi. Take a can of each, unaltered, and I can pick out the Coke every time. Now with fountain drinks, shaking them up, whatever may alter them, then maybe I couldn't, but in can or bottle, every time.

People that can hear differences in amps and what not should be able to the same thing.


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## ChrisB

89grand said:


> I'll just say this. Many people claim to be able to hear the differences between amps, cables, power wire or whatever, yet not one single person has ever been able to prove it.
> 
> Weird huh?



Psychoacoustics are a powerful factor in helping one justify why they were separated from their money. I know, because I once fell for the hype and BS myself.

As for being able to tell a difference between a quality class D amplifier and a comparable class a/b amplifier in the area of the auditory spectrum where the human ear is least sensitive to changes in frequency... Someone is going to have to prove that one to me. I've tried MANY amplifiers on the same subwoofer, in the same car, with virtually the same setup, and I have yet to notice a significant difference in sound quality when it comes to reproducing the frequencies between 20 and 80 Hz.


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## t3sn4f2

Niebur3 said:


> Are you kidding me, people trying to taste a difference between organic and non organic food. If we are going there....how about filtered water for that matter, say you can't tell a difference with that.


You obviously missed the point of the clip.


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## generalkorrd

I would say that changing your speakers/subs are going to have much more effect on the sound than changing amps. With that being said, I do feel that if you were to make a big enough jump, say from a audiobahn to an audison, you would hear the difference. When I sold home audio back in the day, I used to A/B amps and recievers all the time, and it was easy to hear the difference-mostly in imaging, depth, and spaciousness rather than in tonality.


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## t3sn4f2

Richard Clark Amplifier Challenge FAQ 

Yes, we are allowed to bring it up once a month!


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## generalkorrd

I like how in those rules it says that amps can not exhibit "excessive noise". Hello, that is one of the criteria for a good amp vs a ****ty one. I also like how if he doesnt like the frequency response of an amp, he can put an eq in there to "match" them up. Again, Hello!


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## [email protected]

89grand said:


> I'll just say this. Many people claim to be able to hear the differences between amps, cables, power wire or whatever, yet not one single person has ever been able to prove it.
> 
> Weird huh?


Well where is the proof class d sounds like class a/b? It goes both ways.

IMO I dont run class D ever, I have a/b mono amps


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## t3sn4f2

generalkorrd said:


> I like how in those rules it says that amps can not exhibit "excessive noise". Hello, that is one of the criteria for a good amp vs a ****ty one. I also like how if he doesnt like the frequency response of an amp, he can put an eq in there to "match" them up. Again, Hello!




I don't think you'll find one person here that is suggesting people should buy a bottom dollar flea market piece of **** amp instead of a $200 competent and accurately rated one. What we are saying is that a $200 one will sound the same as a $2000 similarly rated one. In that comparison S/N ratio is not important in a typical setup.

The FR of amp will be flat unless altered intentionally by design. The EQ'ing in the challenge is for those amps that come with a circuit that intentionally alters the flat curve. To bring it back to baseline.

FR is an indication of quality?

Secrets of Home Theater and High Fidelity - Projection Systems Theater PC Case

Here's the base FR curve (in yellow) for one of the best processors out there. PXA-H900.


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## t3sn4f2

BeatsDownLow said:


> Well where is the proof class d sounds like class a/b? It goes both ways.
> 
> IMO I dont run class D ever, I have a/b mono amps


Burden of proof falls on the one making the claim.

Richard Clark proved his case thousands of times already.

The ball has been in the oppositions court forever now.


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## generalkorrd

I understand how that test is run, but to me is a ******** test. I want to A/B the raw amp, with no external eq, or gadget on it. If I have to eq it, I probably wont choose it over one that needs no extra massaging. For example, when I get a steak, if I have to put sauces on it, it's not a good steak, the best steak is one that tastes amazing with nothing extra on it. Do the A/B my way, and you will be able to pick them out, which is the point... amps have a different sound.


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## [email protected]

t3sn4f2 said:


> Burden of proof falls on the one making the claim.
> 
> Richard Clark proved his case thousands of times already.
> 
> The ball has been in the oppositions court forever now.


I bet I could modify 2 speakers to sound the same to, we have been through this a million times. Ya if you want to mod them then they can sound the same, big deal, but we dont used modded amps in the real world. SO I agree with his challenge, but in the real world it is complete ********


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## Indiansprings

generalkorrd said:


> I understand how that test is run, but to me is a ******** test. I want to A/B the raw amp, with no external eq, or gadget on it. If I have to eq it, I probably wont choose it over one that needs no extra massaging. For example, when I get a steak, if I have to put sauces on it, it's not a good steak, the best steak is one that tastes amazing with nothing extra on it. Do the A/B my way, and you will be able to pick them out, which is the point... amps have a different sound.


Your way, my way, his way?? You still will not hear a change in your sub woofer. As a matter of fact, I will go out on a limb and say some of the newer Class D tech. might be up there with the high end A/B amps. I am not talking about just sub Hz, Im talking about Hz north of 80Hz.


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## [email protected]

Indiansprings said:


> Your way, my way, his way?? You still will not hear a change in your sub woofer. As a matter of fact, I will go out on a limb and say some of the newer Class D tech. might be up there with the high end A/B amps. I am not talking about just sub Hz, Im talking about Hz north of 80Hz.


LOL, thats funny, make sure that limb is strong so it doesnt break on you


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## generalkorrd

BeatsDownLow said:


> LOL, thats funny, make sure that limb is strong so it doesnt break on you


Alpine PDX anyone?


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## generalkorrd

Indiansprings said:


> Your way, my way, his way?? You still will not hear a change in your sub woofer. As a matter of fact, I will go out on a limb and say some of the newer Class D tech. might be up there with the high end A/B amps. I am not talking about just sub Hz, Im talking about Hz north of 80Hz.


Richard Clark is not the be all end all of audio. His test just shows that 2 amps that are eq'd to match each other will sound so similar as to be indistinguishable from each other. The real world that Beats and I speak about is the one where you do a true a/b test with nothing else in the signal chain, and all adjustments at zero, outside of gain which is matched to each other to exclude volume from the test. You will hear a difference.


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## ghostmechanic

t3sn4f2 said:


> Richard Clark proved his case thousands of times already.


LOL!



06BLMUSTANGGT said:


> Psychoacoustics are a powerful factor in helping one justify why they were separated from their money. I know, because I once fell for the hype and BS myself.


Very well said & I've been there as well. I think most people have. What's funny are all the people that make claims like "I can hear the difference between this amp brand & that amp brand". Sometimes that might be the case but there are so many amps out there that are the same amp just dressed in different clothes that unless you know the ones that actually are different, you're mind is just playing tricks on you. Most people would be surprised how few actual manufacturing brands there are out there for amps & speakers as well. This has been the case for many years & the more years that move on, the fewer there are. Even back in the "old school" days most popular brands of amps were either made by ZED or PPI. Yes I know Soundstream, Orion & few others don't fall under that category.


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## t3sn4f2

Gracefully bowing out now.......


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## ChrisB

t3sn4f2 said:


> Gracefully bowing out now.......


I'm right behind you!


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## Indiansprings

Moving on as well. It was fun while it lasted.


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## gijoe

This argument comes up all the time.

To the OP: Sure different amps may sound different, then again they may not. At subwoofer frequencies there is no reason why a good class D will sound any different than a class A/B.

I don't entirely doubt the people who claim to hear a difference from one amp to another, but I personally don't think that it is because of the different class of the amps. 

Given the frequency range that a sub plays, your best bet is to get the most efficient power you can afford (Class D), I highly doubt that the people who claim to hear a difference from one amp to another has done a proper comparison. If you install a switch for instantaneous switching between amps you may be able to hear a slight difference, but listening to one, uninstalling it, installing another amp and listening again is going to be FAR from reliable.


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## MarkZ

generalkorrd said:


> I like how in those rules it says that amps can not exhibit "excessive noise". Hello, that is one of the criteria for a good amp vs a ****ty one. I also like how if he doesnt like the frequency response of an amp, he can put an eq in there to "match" them up. Again, Hello!


That's actually the point he's trying to make... that amps can be made to sound the same, not that amps will sound the same out of the box. In the rules, he's basically acknowledging that there are differences, and he spells out what those differences are. There are a lot of people who think there are OTHER differences beyond freq response, noise level, etc -- and those are the folks he's trying to persuade.


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## MarkZ

generalkorrd said:


> I understand how that test is run, but to me is a ******** test. I want to A/B the raw amp, with no external eq, or gadget on it. If I have to eq it, I probably wont choose it over one that needs no extra massaging. For example, when I get a steak, if I have to put sauces on it, it's not a good steak, the best steak is one that tastes amazing with nothing extra on it. Do the A/B my way, and you will be able to pick them out, which is the point... amps have a different sound.


Yeah, but if you can use a $100 dollar amp with a $100 dollar EQ and make it INDISTINGUISHABLE from the $10,000 amp, why wouldn't you?


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## MarkZ

BeatsDownLow said:


> I bet I could modify 2 speakers to sound the same to, we have been through this a million times. Ya if you want to mod them then they can sound the same, big deal, but we dont used modded amps in the real world. SO I agree with his challenge, but in the real world it is complete ********


I'd love to see you make the speakers in my tv sound like a Fountek FR88. How, exactly, would you do that?


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## smithee419

I knew that this wasn't gonna go anywhere!


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## Niebur3

89grand said:


> I'll just say this. Many people claim to be able to hear the differences between amps, cables, power wire or whatever, yet not one single person has ever been able to prove it.
> 
> Weird huh?


I know...it is very wierd, you are making a claim as well and can't prove it...where is your technical proof they do sound the same. You made the first, your burden of proof!



t3sn4f2 said:


> Richard Clark Amplifier Challenge FAQ
> 
> Yes, we are allowed to bring it up once a month!


So, lets see, can we eq to different amps and have them sound the same. I'm sure you can get close enough to be extremely hard to tell a difference, but do you guys realize what an eq does to an amp? Do you realize that "band aid" you put on your amp to make it sound the same....those 6 and 9 dB peaks put an insane amount of stress on the amp. I wonder which will last longer?? I wonder when you stress the amp to that extent, at that particular moment, how does it sound? It can be a subtle difference that you say to yourself...."I can't put my finger on it, but it just sounds a little off". That is the difference. If Class D or Class A/B sound the same, then why do all music mastering companies (the ones that mix the music you listen to) use all class A amplifiers. Why would they spend the insane amount of monthly cost for something they only hear?


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## slomofo

I guess I should toss out the Soundstreams and Xtants and just run some ****box Rampage amps. I mean, if they are all really apples..... 
No machine can duplicate what the ear hears and what the mind does with what the ears hear. I'm sorry, I've been doing this too long to buy into Richard Clarks amp tests. Yes they are acurate, but nothing can tell what the mind perceives, whether the mind is tainted with pride of ownership or not. 
How many of you have ever heard a car that scored a 37 or better on the RTA back when a perfect was 40. They sound like crap in my opinion, but I'll say it again. What one perceives as sound quality is just that, perception. It's all subjective.


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## ca90ss

Niebur3 said:


> those 6 and 9 dB peaks put an insane amount of stress on the amp.


What kind of amps are you using that have a 9db deviation in their frequency response?


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## t3sn4f2

Niebur3 said:


> I know...it is very wierd, you are making a claim as well and can't prove it...where is your technical proof they do sound the same. You made the first, your burden of proof!
> 
> 
> 
> So, lets see, can we eq to different amps and have them sound the same. I'm sure you can get close enough to be extremely hard to tell a difference, but do you guys realize what an eq does to an amp? Do you realize that "band aid" you put on your amp to make it sound the same....those 6 and 9 dB peaks put an insane amount of stress on the amp. I wonder which will last longer?? I wonder when you stress the amp to that extent, at that particular moment, how does it sound? It can be a subtle difference that you say to yourself...."I can't put my finger on it, but it just sounds a little off". That is the difference. If Class D or Class A/B sound the same, then why do all music mastering companies (the ones that mix the music you listen to) use all class A amplifiers. Why would they spend the insane amount of monthly cost for something they only hear?


Read what MarkZ wrote above about the challenge.

Last time I check, any cheap competent amp has around +0db/-.5dB from 20Hz-20Khz and the drop is only at the very end of the 20Khz range. It's not a wobbly line in between that, they're FLAT from 30Hz-10KHz at least.

Look at a Kenwood KAC-X4R for example.

Also, I don't see how that .25dB you get back at 20Khz! when you pay 10x the amount for a high end amp is of any use since you can't hear it and your car or room's transfer function would put the FR it ALL over the map relative to that minuet amount. This is the reason EQ's don't adjust in .25dB increments, because it don't matter, you can't hear the change.


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## t3sn4f2

slomofo said:


> *I guess I should toss out the Soundstreams and Xtants and just run some ****box Rampage amps. I mean, if they are all really apples.....*
> No machine can duplicate what the ear hears and what the mind does with what the ears hear. I'm sorry, I've been doing this too long to buy into Richard Clarks amp tests. Yes they are acurate, but nothing can tell what the mind perceives, whether the mind is tainted with pride of ownership or not.
> How many of you have ever heard a car that scored a 37 or better on the RTA back when a perfect was 40. They sound like crap in my opinion, but I'll say it again. What one perceives as sound quality is just that, perception. It's all subjective.


Waow.


----------



## slomofo

t3sn4f2 said:


> Waow.


well, that's kinda what all these threads suggest is that all amps sound the same (hey someone else went there, not me) and that no one in their right mind could ever ever tell the difference between a class D monoblock and a class a/b. so my point stands, throw out the class A soundstream and bring in the pdx amps, they all sound the same. all of them, every last one. for the record, i've done installs with the pdx and i think they sound just fine for the regular listener, but i'll keep my made in the usa class a/b as i tend to find a better reproduction experience. for the record, i paid nothing for them so there is no pride issue. same with the soundstreams


----------



## Niebur3

t3sn4f2 said:


> Waow.


I thought you were "Gracefully bowing out now?" Does anyone have anything to comment about why sound engineers use a class A amplifier??? Spend thousands of dollars a month just to power the thing??? They have ears that are trained to pick out peaks and dips and can you at what frequency these dips are without seeing anything on a computer. I know, I have talked to a local guy and met with him many times. He can sit in my car (with the eq off) and tell where my peaks and dips are. Can you guys that can't hear a difference do that? Do you think he likes to spend that kind of money on electricity if it didn't make a difference? Can you guys hear recording flaws in music? Do you not believe people have different levels of hearing?


----------



## gijoe

We're still talking about subwoofer frequencies right? Like 20hz-200hz max...within that limited range, in a noisy car there is no reason to not use class D.


----------



## generalkorrd

gijoe said:


> We're still talking about subwoofer frequencies right? Like 20hz-200hz max...within that limited range, in a noisy car there is no reason to not use class D.


You make a good point, Ill give you that. For 90 percent of people out there this is correct, but you always have your picky ones like me and a few otheres that see the value in a 1000 dollar a/b amp. 

FYI, I'll bet any kind of money that Richard Clark does not use cheap anything in his audio, either car or house. Names like Krell, Crown, Audison, Martin Logan come to mind.


----------



## t3sn4f2

Niebur3 said:


> I thought you were "Gracefully bowing out now?" Does anyone have anything to comment about why sound engineers use a class A amplifier??? Spend thousands of dollars a month just to power the thing??? They have ears that are trained to pick out peaks and dips and can you at what frequency these dips are without seeing anything on a computer. I know, I have talked to a local guy and met with him many times. He can sit in my car (with the eq off) and tell where my peaks and dips are. Can you guys that can't hear a difference do that? Do you think he likes to spend that kind of money on electricity if it didn't make a difference? Can you guys hear recording flaws in music? Do you not believe people have different levels of hearing?


I decided to return, but I'm leaving again. I might come back though, but I might not. Maybe.


----------



## 14642

This is begining to sound like a health care reform town hall meeting. Kudos to those who can agree to disagree. It would be great if people would understand the difference between "I believe" and "It is known".


----------



## MarkZ

Niebur3 said:


> I know...it is very wierd, you are making a claim as well and can't prove it...where is your technical proof they do sound the same. You made the first, your burden of proof!


The problem is that you're asking him to prove the null hypothesis.

Think of it this way: if he finds a pair of amplifiers that sound the same, will that mean that all amplifiers sound the same? Of course not. Just like if you found a pair of amplifiers that sound different, that doesn't mean that all amplifiers sound different.

In this case, the hypothesis is that there are some amps that sound different from other amps. All you have to do to confirm the hypothesis is show that there's at least one pair that sound different (well...barring statistical issues...).

If you want HIM to do the proving, then you'd have to re-frame the hypothesis to be: there are some amps that sound the same as other amps. But I don't think ANYBODY would disagree with that premise.

So, for this matter, the burden of proof IS on the "some amps sound different from other amps" crowd.



> So, lets see, can we eq to different amps and have them sound the same. I'm sure you can get close enough to be extremely hard to tell a difference, but do you guys realize what an eq does to an amp? Do you realize that "band aid" you put on your amp to make it sound the same....those 6 and 9 dB peaks put an insane amount of stress on the amp. I wonder which will last longer?? I wonder when you stress the amp to that extent, at that particular moment, how does it sound? It can be a subtle difference that you say to yourself...."I can't put my finger on it, but it just sounds a little off". That is the difference.


Longevity is quite another issue, but a valid point nonetheless. However, do you honestly believe that there are some amps that need 6-9dB of EQing to get flat? Even crappy wal-mart amps only have deviations of about 1dB...



> If Class D or Class A/B sound the same, then why do all music mastering companies (the ones that mix the music you listen to) use all class A amplifiers. Why would they spend the insane amount of monthly cost for something they only hear?


Um...you sure about that?


----------



## slomofo

t3sn4f2 said:


> I decided to return, but I'm leaving again. I might come back though, but I might not. Maybe.


vague.....


----------



## MarkZ

Niebur3 said:


> I thought you were "Gracefully bowing out now?" Does anyone have anything to comment about why sound engineers use a class A amplifier??? Spend thousands of dollars a month just to power the thing??? They have ears that are trained to pick out peaks and dips and can you at what frequency these dips are without seeing anything on a computer. I know, I have talked to a local guy and met with him many times. He can sit in my car (with the eq off) and tell where my peaks and dips are. Can you guys that can't hear a difference do that? Do you think he likes to spend that kind of money on electricity if it didn't make a difference? Can you guys hear recording flaws in music? Do you not believe people have different levels of hearing?


You bring up lots of issues. Let's see if I can tackle them all. First of all, I wouldn't use "sound engineers" as a benchmark for much of anything. If you've bought a CD lately, you'll know why.  

Seriously though, like EVERY other field out there, there are some people who are good at their jobs and some people who are bad at their jobs. I know, personally, quite a few audio engineers. There are even a couple on this forum! Some would share your reverence for class A, and some wouldn't. Just because the ones that YOU know agree with you, or use class A amplifiers, doesn't mean that all of them do.

Anyway, I think it's an avenue not worth pursuing. We can debate the merits of class D or whatever without having to bring in other people who can't even speak for themselves. Let's try to keep it to just those of us who are actually members. 

As for being able to pick out peaks and dips and such, I think you'd actually be surprised that a lot of folks in this forum do that sort of thing regularly. Some of them even do it for a living. If you can't, that's cool, but don't assume that everybody else here is at your level.


----------



## t3sn4f2

comfy_shoes said:


> hi there I was wondering if looking for sq out of your sub woofer....wether going with a a/b or d class amp will make much of an audible difference. I am considering a kicker amp . I am curious to know wether the a/b zx400.2 bridged in mono or the zx400.1 class d will be a better choice. is there a percievable sound quality difference from anyones experience?


Ok, back on topic then.

I've never heard them, but based on this post alone, *I* would get the zx400.1 *if I* was you. That, IMHO <~~~ is as good a recommendation as one from someone who's "heard and compared them both".

Don't ask me why though.


----------



## t3sn4f2

double post........


----------



## smithee419

I was just looking at kickers website and I don't see a zx400.2 I see a zx450.2. Is the zx400.2 an older model #?


----------



## ChrisB

smithee419 said:


> I was just looking at kickers website and I don't see a zx400.2 I see a zx450.2. Is the zx400.2 an older model #?


Older model: Kicker ZX400.1 Mono subwoofer amplifier 400 watts RMS x 1 at 2 ohms at Crutchfield.com


----------



## smithee419

Yeah I see the zx400.1, but no zx400.2 he wants to know which one to buy, but I can't find a zx400.2.


----------



## ChrisB

Oops, my bad... I mixed the 1 and 2 up. 

ETA: I don't think there is a Kicker zx400.2...

ETA2: They did make a KX400.2 though


----------



## Niebur3

t3sn4f2 said:


> Ok, back on topic then.
> 
> I've never heard them, but based on this post alone, *I* would get the zx400.1 *if I* was you. That, IMHO <~~~, is as good a recommendation as one from someone who's "heard and compared them both".
> 
> Don't ask me why though.


I guess to be on topic, like I did post earlier, buy either one. The are both made by Kicker . I would recommend even a class D amp if we can recommend a better quality amp. How much money is he planning to spend on these amps? Maybe there is something better out there!


----------



## ashlar

If it is any consolation, Mark Eldridge uses ALL class D amps, even on his subs. Must not be all that bad, huh?


----------



## t3sn4f2

ashlar said:


> If it is any consolation, Mark Eldridge uses ALL class D amps, even on his subs. Must not be all that bad, huh?


"Yes but.................."


----------



## ALL4SQ

I've have nothing but good things to Say about my JL HD amps.
Now if someone would build something similar for about 1/3rd the price we would be good to go!  I still think an amplifier with less parts should cost less......


----------



## t3sn4f2

ALL4SQ said:


> I've have nothing but good things to Say about my JL HD amps.
> Now if someone would build something similar for about 1/3rd the price we would be good to go!  I still think an amplifier with less parts should cost less......


An ounce of brains is worth more then an ounce of aluminum.


----------



## Niebur3

ashlar said:


> If it is any consolation, Mark Eldridge uses ALL class D amps, even on his subs. Must not be all that bad, huh?


That is funny! Yes they say JLHD on them, but do you really think that is what is underneath??? He did spend years working there as head of product development. I'm sure they are just a little bit different than the ones we are able to buy in the stores on the inside (meaning completely different), but having the same outside sure sells the product .


----------



## t3sn4f2

Niebur3 said:


> That is funny! Yes they say JLHD on them, but do you really think that is what is underneath??? He did spend years working there as head of product development. I'm sure they are just a little bit different than the ones we are able to buy in the stores on the inside (*meaning completely different*), but having the same outside sure sells the product .


JL commissions "Single Cycle Control" from another company, re engineers it making it better, and keeps it to themselves while introducing a crappy HD amp.


----------



## ashlar

Just imagine what would happen the day Mark Eldridge desides to get rid of those dirty-sounding class D amps and use class A/B amps instead.


----------



## Niebur3

t3sn4f2 said:


> JL commissions "Single Cycle Control" from another company, re engineers it making it better, and keeps it to themselves while introducing a crappy HD amp.


Are you serious? Why do they do that? It seems like small amp are a very high selling novelty right now...maybe it will last, I just hope sound quality does not suffer to much while they try to make them pocket size...lol.


----------



## t3sn4f2

Niebur3 said:


> Are you serious? Why do they do that? It seems like small amp are a very high selling novelty right now...maybe it will last, I just hope sound quality does not suffer to much while they try to make them pocket size...lol.


"*C*ome onnn maaaaaan!"


----------



## comfy_shoes

I own a kicker kx300.4 now. and find it to be great. power wise and sq wise. however I havn't had much other brands. what are good brands of amps that are affordable. I'll pay up to 250$ for an amp. I noticed the jbl GTO series amps have near 108db signal-to-noise ratios and very low THD due they compare with kicker power out put wise? 

another thing to with the class A/B and D comparison I asked about. I am under the impression that A/B is 60% effiecient per watt compared to class D. so to realy compare would you have to compare a 1000 watt class A/B to a 600 watt class D ...sorry if math isn't bang on. I'm tired. lol

I was happy with my kicker kx amp. however is it true that the new zx are noisey? if so how noticeable. car audio is so competitive that theres a huge compromise between cost of amp and marketing....wich affordable amp manufacturers spend the least on marketing. I'd base a strong generalization of sq quality on the one that spent the least...lol.....there has to be a way to find common ground....less money spent for marketing is a good generalization I like to make. anyway...how about wich affordable amp up to 250$ and can handle [email protected] ohms would you recommend that will move my sub accurately?


----------



## Niebur3

ashlar said:


> Just imagine what would happen the day Mark Eldridge desides to get rid of those dirty-sounding class D amps and use class A/B amps instead.




Then maybe he would win sometimes....lol. Have you heard his car? His speaker setup is really different. 2 sets (mid and tweet) left, center, and right with phasing inverted in certain frequencies to cancel out reflection and do other "Stuff". I read over his install book, wish I had it for about a week (or month, or year) to understand it all .


----------



## Niebur3

t3sn4f2 said:


> "*C*ome onnn maaaaaan!"


what....where we going :laugh:


----------



## Niebur3

comfy_shoes said:


> I own a kicker kx300.4 now. and find it to be great. power wise and sq wise. however I havn't had much other brands. what are good brands of amps that are affordable. I'll pay up to 250$ for an amp. I noticed the jbl GTO series amps have near 108db signal-to-noise ratios and very low THD due they compare with kicker power out put wise?
> 
> another thing to with the class A/B and D comparison I asked about. I am under the impression that A/B is 60% effiecient per watt compared to class D. so to realy compare would you have to compare a 1000 watt class A/B to a 600 watt class D ...sorry if math isn't bang on. I'm tired. lol
> 
> I was happy with my kicker kx amp. however is it true that the new zx are noisey? if so how noticeable. car audio is so competitive that theres a huge compromise between cost of amp and marketing....wich affordable amp manufacturers spend the least on marketing. I'd base a strong generalization of sq quality on the one that spent the least...lol.....there has to be a way to find common ground....less money spent for marketing is a good generalization I like to make. anyway...how about wich affordable amp up to 250$ and can handle [email protected] ohms would you recommend that will move my sub accurately?


If you are looking to spend $250 and want decent quality, go with a JL 500/1 "Class D" and it will work just fine. Waaaaaaaaayyyy better than the kicker.


----------



## ashlar

Niebur3 said:


> That is funny! Yes they say JLHD on them, but do you really think that is what is underneath??? He did spend years working there as head of product development. I'm sure they are just a little bit different than the ones we are able to buy in the stores on the inside (meaning completely different), but having the same outside sure sells the product .


Actually, Mark never worked for JL Audio in that capacity. Don't believe me, check it out for yourself.

Mark Eldridge joins JL - Car Audio & Electronics Forums at Car Audio and Electronics Magazine

The amps may have the JL Audio badge on them on the outside, but what makes them oh, so very special, is what is on the inside. On the inside contains another of Bruce Macmillan's latest design and that's one reason why they have such a cult following. With his designs, I care little for whose badge is on the outside. Personally speaking, I follow his work.


----------



## ChrisB

Niebur3 said:


> If you are looking to spend $250 and want decent quality, go with a JL 500/1 "Class D" and it will work just fine. Waaaaaaaaayyyy better than the kicker.


He should follow your advice only if he wants one of the most inefficient class D amps on the market.

ETA: Here is a link to one of the reviews on the 500/1: http://www.carsound.com/review_archive/amps/jl_5001.html


----------



## Niebur3

ashlar said:


> Actually, Mark never worked for JL Audio in that capacity. Don't believe me, check it out for yourself.
> 
> Mark Eldridge joins JL - Car Audio & Electronics Forums at Car Audio and Electronics Magazine
> 
> The amps may have the JL Audio badge on them on the outside, but what makes them oh, so very special, is what is on the inside. On the inside contains another of Bruce Macmillan's latest design and that's one reason why they have such a cult following. With his designs, I care little for whose badge is on the outside. Personally speaking, I follow his work.


Sorry, that is what I meant. I remembered it wrong.


----------



## comfy_shoes

I am considering a jl amp. if the price is right!!!!!

some people mentioned that I should focus more on enclosure design then my amp for sq that I agree 100% with. I built a sealed box out of 3/4" mdf and sprayed the inside with acoustic stucco!!. I liked the sound. however it vibrated a tad. I just put a second layer of mdf on it making the walls 1 1/2" thick. wow what a difference......I think I am going to make a concrete enclosure....try to keep it to around 60-70lbs and 1.25 cu ft...I use an infinity 12" reference sub now(1260w) I like it even thow it's cheap!


----------



## Niebur3

06BLMUSTANGGT said:


> He should follow your advice only if he wants one of the most inefficient class D amps on the market.


So instead of a flip remark, why don't YOU give him a suggestion.


----------



## smithee419

I would pick the JL Audio 500/1 amp also over the Kicker, as mentioned before. $250 seems low, unless he gets a used 1.


----------



## ChrisB

Niebur3 said:


> So instead of a flip remark, why don't YOU give him a suggestion.


Sure, I can do that. 

To the OP, pick any subwoofer amp within your budget that gives you the power you desire because chances are you won't notice the difference anyhow. The things you should look for are cost, reliability, efficiency, and clean RMS output.:laugh:

Unless:

the damping factor is less than 50, chances are you won't hear the difference. 

the THD is more than 1%, chances are you won't notice the difference. 

you are running some subs that can actually reproduce hiss in the form of some odd harmonics, you probably won't notice the difference in signal to noise ratio either. This factor is further reduced if your subwoofer is in a trunk vehicle.

See, that makes it easy, doesn't it? I think I narrowed his choices down to at least 100 amps, give or take a few.


----------



## MarkZ

06BLMUSTANGGT said:


> Sure, I can do that.
> 
> To the OP, pick any subwoofer amp within your budget that gives you the power you desire because chances are you won't notice the difference anyhow. The things you should look for are cost, reliability, efficiency, and clean RMS output.:laugh:
> 
> Unless:
> 
> the damping factor is less than 50, chances are you won't hear the difference.
> 
> the THD is more than 1%, chances are you won't notice the difference.
> 
> you are running some subs that can actually reproduce hiss in the form of some odd harmonics, you probably won't notice the difference in signal to noise ratio either. This factor is further reduced if your subwoofer is in a trunk vehicle.
> 
> See, that makes it easy, doesn't it? I think I narrowed his choices down to at least 100 amps, give or take a few.


I like this advice and I'll take it one step further. Put whatever extra money that you were going to spend on an expensive amp, and dedicate it to your subwoofer and its enclosure, so you don't have to make a hulking monstrosity out of concrete. 

On a serious note, put a lot of thought into enclosure type, geometry, and location, and then choose the right subwoofer based on those decisions. Build it with attention to detail. AFTER you've done all that, then choose an amp with whatever money you have left.


----------



## Niebur3

06BLMUSTANGGT said:


> Sure, I can do that.
> 
> To the OP, pick any subwoofer amp within your budget that gives you the power you desire because chances are you won't notice the difference anyhow. The things you should look for are cost, reliability, efficiency, and clean RMS output.:laugh:
> 
> Unless:
> 
> the damping factor is less than 50, chances are you won't hear the difference.
> 
> the THD is more than 1%, chances are you won't notice the difference.
> 
> you are running some subs that can actually reproduce hiss in the form of some odd harmonics, you probably won't notice the difference in signal to noise ratio either. This factor is further reduced if your subwoofer is in a trunk vehicle.
> 
> See, that makes it easy, doesn't it? I think I narrowed his choices down to at least 100 amps, give or take a few.


Wow....way to help a guy out. If he types that in the search engine, will it will pull up some amps in classifieds??


----------



## slomofo

a point of relevance for all this. I run 2 JL 10w3's sealed. I used to run them off the sub channel of a zx550.3. that amp is essentially a zx75.2 and 400.1 under one heatsink. the class D section of that amp worked really well. it was a dynamite amp. I removed it and installed an Xtant X604 running 2ohm stereo to the same woofers. the Xtant seemed to have more control and less of a tubby sound. same woofers, same enclosure, same mids and tweets, same cables. just changed the amp. maybe i'm stubborn, maybe i'm wrong, but i'm not deaf, not by a long shot


----------



## MarkZ

slomofo said:


> a point of relevance for all this. I run 2 JL 10w3's sealed. I used to run them off the sub channel of a zx550.3. that amp is essentially a zx75.2 and 400.1 under one heatsink. the class D section of that amp worked really well. it was a dynamite amp. I removed it and installed an Xtant X604 running 2ohm stereo to the same woofers. the Xtant seemed to have more control and less of a tubby sound. same woofers, same enclosure, same mids and tweets, same cables. just changed the amp. maybe i'm stubborn, maybe i'm wrong, but i'm not deaf, not by a long shot


"Tubby sound" might indicate a frequency response difference of some sort. This could be a byproduct of either clipping or simple level matching (coherence with midbass drivers is a common cause of ~80Hz 'hooting', if that's what you're referring to). Or, if you were using onboard crossovers, that's always a FR culprit. 

I don't know what "more control" sounds like. 

At any rate, it's hard to do direct comparisons between amps without careful level matching. And by "careful", I mean hauling out the o-scope.


----------



## ashlar

06BLMUSTANGGT said:


> He should follow your advice only if he wants one of the most inefficient class D amps on the market.
> 
> ETA: Here is a link to one of the reviews on the 500/1: JL Audio 500/1


That's a very good review, but here is an answer to your efficiency question.

"Why are our Class D's less efficient than others? Partially because of the regulated power supply, partially because of the patented feedback loop design we implement to improve fidelity. So, we compromised some efficiency to improve sound quality."

In the above he is referring to the Slash series of class D amplifiers. 

The HD amplifiers are a different story as far as efficiency is concerned.


----------



## Niebur3

Not going to argue anymore...senseless.


----------



## ashlar

In that carsound review did anyone notice that the 500/1 was under-rated to the tune of 233 watts? And at 10.5 volts it was outputting 598 volts, well above rated spec driving a 60 Hz signal? Just imagine that.


----------



## MarkZ

Niebur3 said:


> I like how Zed Amps and JL Amps state how class D sq has suffered and what they have done to resolve that and produce better sq class D, but I'm sure they did not hear a difference....a troll told them in their sleep.
> 
> Besides, is the efficiency thing a real big issue for most? If you run 4-5 amps, maybe, but 1 or 2?


If we were to point out all the different flaws on Mantz's and JL's site, we'd have to devote a whole new thread to the topic. Remember, JL's "tutorials" site is the one that changes every year or so to reflect the fact that the lies they tell are no longer being taken as fact by the consumer (see: Adire Audio schooling them on the DVC wiring issue...). :laugh:

And yeah, I care about efficiency. I'm already on the threshold of dimming. It's only noticeable when my lights are reflecting off something. If it got any worse, it'd probably be just enough to annoy me. Also, I can't spare much space or temperature increases in my trunk (the sub amp is located near my computer).

Embrace technology, dude.


----------



## ALL4SQ

t3sn4f2 said:


> An ounce of brains is worth more then an ounce of aluminum.



Your comment has nothing to do with the subject.

The JL HD amps work very well in my car. Plenty of Noise free power in a small package. 

I don't personally believe anyone can hear a difference between classes of amps. The problem comes in with the setup. If the gains are not matched across the frequency range than you might hear a small difference. Matching the gains does not require an EQ either. Most amps will be +/- 1db across the frequency range. The two amps need to be matched so your not creating a 2db difference in the frequencies that the Human hearing is most sensitive to. 

Personally I buy a Quality amp for reasons other than the way some SQ Snob thinks it sounds. I also laugh when I hear a Rep for a speaker company say there speakers will sound bad when used with a class D amp. Its the speaker that sounds bad, not the amp.


----------



## dkh

Niebur3 said:


> There is no technical proof unless you can tap into my brain some how...just like specs can't always tell the whole story about a speaker.
> 
> I'm not dumb, I have done an AB comparison with amps, hu, speakers and eq, time alignment, crossover points, etc. When you hook 1 amp brand to 1 side and 1 amp brand to the other, match level and listen, there IS a difference. Same with HU, etc. I used to try to play that trick on my wife when tuning, just to see if she actually heard it and she was right every time, not almost every time, but EVERY time. I would say, there, how does that sound after NOT changing something in the back and she would simply say, "it sounds the same". You need not to only have a great overall system, but you need great hearing and a great memory. If you are playing a track for the 1st time, some may not hear a difference, but if you play something you know better than anything...then the difference is like a slap in the face.





89grand said:


> I'll just say this. Many people claim to be able to hear the differences between amps, cables, power wire or whatever, yet not one single person has ever been able to prove it.
> 
> Weird huh?


I can hear a difference between a Genesis DM and a Sinfoni 45.2x 

So could my friend ???? Yet both these amplifiers are high-end class A/B type designs 

The same system with firstly vandam studio speaker cable then chord rumour 2...

I know, it was all in our heads


----------



## Vega-LE

One may not be able to hear distortion in the form of background noise. But, I can tell the clarity of the music is not as detailed with class D. Those class D's guts do look awful pretty though.


----------



## t3sn4f2

ALL4SQ said:


> Your comment has nothing to do with the subject.
> 
> The JL HD amps work very well in my car. Plenty of Noise free power in a small package.
> 
> I don't personally believe anyone can hear a difference between classes of amps. The problem comes in with the setup. If the gains are not matched across the frequency range than you might hear a small difference. Matching the gains does not require an EQ either. Most amps will be +/- 1db across the frequency range. The two amps need to be matched so your not creating a 2db difference in the frequencies that the Human hearing is most sensitive to.
> 
> Personally I buy a Quality amp for reasons other than the way some SQ Snob thinks it sounds. I also laugh when I hear a Rep for a speaker company say there speakers will sound bad when used with a class D amp. Its the speaker that sounds bad, not the amp.


I don't get it.....

You said an amps with less parts should cost less, referring to a jl hd amp.

What I said was referring to them as well. They don't have less parts. They have more parts in order to be able to do things like be regulated and have adaptive rails and whatever else. So the brains that is needed to do those things is worth more then the AL you save from the increase in efficiency. That's where the extra cost comes from. 

IOW, its not smaller because there are less parts in it, it's smaller because you need less heat sink due to increased efficiency. You pay extra for the complexity of the design.


----------



## Niebur3

Not going to argue anymore...senseless.


----------



## t3sn4f2

Niebur3 said:


> You tell me to embrace technology when most all high end amps are still class A/B designs. How many amps are you running in your car? You are on the threshold of dimming....poor thing. It annoys me more when my stereo sounds like ****. I'll take a little light dimming at a stop when headlights on and the stereo up very loud - there are worse things in life.
> 
> Where you your class G....come on, embrace technology!
> *
> You have a sub located near your computer and you worry about temp increasing? What does the sub near the computer have to do with which amps you buy*?


His _sub amp _is next to the computer, so a more efficient amp would be better since they put out less heat watts next to the computer.


----------



## Niebur3

Not going to argue anymore...senseless.


----------



## t3sn4f2

Niebur3 said:


> Fans costs like $2-$3 at radio shack .












Sweeeeeeeet


----------



## t3sn4f2

Niebur3 said:


> Fans costs like $2-$3 at radio shack .
> 
> Are you referring to a carputer?


yeah


----------



## Niebur3

Not going to argue anymore...senseless.


----------



## snaimpally

comfy_shoes said:


> whats damping factor? what does it do?


Legendary Audio Classics: Damping Factor

The main issue with using a class AB for a sub, besides the current draw, is that most class AB amps are stable at loads less than 4 ohms. If you plan to run subs with a net impedance of less than 4 ohms, get a class D amplifier. Also, I think the amp manufacturer is a bigger factor than class D or class AB. I know someone who was a big proponent of using class AB amps for subs but now he is using a class D Celestra DA2k amp. Get a good quality (e.g., move up from Kicker) class D sub amp and you will be fine. Check this out:

http://cgi.ebay.com/JBL-BPx-500-1-M...mQQptZSpeakers_Subwoofers?hash=item3ca844f65d

This amp does around 700 watts at 1/2/4 ohms. Excellent price.


----------



## Niebur3

Not going to argue anymore...senseless.


----------



## MarkZ

Niebur3 said:


> You tell me to embrace technology when most all high end amps are still class A/B designs.


Your logic doesn't make any sense. Because there are more they must be better? Class A must sound like dog **** then.



> How many amps are you running in your car? You are on the threshold of dimming....poor thing. It annoys me more when my stereo sounds like ****. I'll take a little light dimming at a stop when headlights on and the stereo up very loud - there are worse things in life.


Or, you could have both good sound AND good efficiency. My point wasn't that dimming is the bane of human existence. My point was that, yes, some people actually DO value efficiency. [Actually, temperature, space, and price were a little more important to me than current draw, but anyways...] 



> Where you your class G....come on, embrace technology!


I've actually got one on the drawing board!  There's been no bigger proponent of class G than me in this forum. So I don't know what you're talking about. You're saying class D is substandard, and I promote class G all the time. So, obviously, I *am* embracing technology.



> You have a sub located near your computer and you worry about temp increasing? What does the sub near the computer have to do with which amps you buy?


Sub amp is near the computer, not the sub. My computer hates high temps in an enclosed trunk behind an enclosed panel, so generating less heat behind that panel is a pretty good side effect of running a class D sub amp.


----------



## MarkZ

Niebur3 said:


> Fans costs like $2-$3 at radio shack .


Gee, I wish I woulda thought of that. 

1) Fans are ghetto. They sound annoying. Even the high cfm low noise fans from newegg (I have a few of those in my home server). That's actually another aspect I use in amplifier selection -- no fans!

2) It's behind an enclosed panel. Where am I going to have the fan blow out of? I'd have to cut a hole in the panel, which I don't really want to do.

It's moot, because I've solved the problem by running an oversized and efficient amplifier that generates very little heat. [in comparison to the amplifiers on the OTHER side that get hot as a bastard...]


----------



## ashlar

comfy_shoes said:


> whats damping factor? what does it do?


http://www.monstercable.com/mpc/stable/tech/A2412_Damping_Factor_Article.pdf


----------



## MarkZ

Niebur3 said:


> So you have a carputer next to your sub and you are worried about heat from the amp? I would think the sub moves enough air to cool the air and I would be more concerned with the effects of vibration on the carputer. Class D doesn't mean you embrace technology, just means you are a sheep. Give me a break if you think the air temperature is that much different next to any amp...little lone different class D amps. If it is, we are not talking much at all.


You can't possibly be serious. You really don't think that putting a computer (made mostly of metal) in an enclosed space with something that gets hot doesn't affect its temperature? Maybe you should try it sometime before you make such claims.

If you know anything about computers, you'll realize that ambient temperature is a pretty big deal, regardless of cooling strategy. And if you know anything about carputers (which I've been installing in cars since 1999), you'll realize that one of a trunk-mounted computer's greatest enemies is temperature. You want to talk about how important longevity is when it comes to amps, but you don't care about how important longevity is when it comes to the computer that RUNS the amps? 

It's a non-issue this time of year though. Maybe I should switch to class B in the wintertime and back to D in the summer. 

As for the vibrations, it's not really a big deal. There's no hiding from a subwoofer. If your install is correct, there should be about the same amount of vibration next to the subwoofer than on the other side of the car. The only thing that's really vibration-sensitive is the hard drive anyway, which is a more easily replaceable part than a motherboard, cpu, or memory in my configuration. Potholes are more of a ***** anyway.  Actually, temperatures are way more of a *****. Below about 15F, the hard drive actually won't spin up (Seagate drives generally will go another 5 deg lower before encountering that problem).


----------



## MarkZ

Niebur3 said:


> Where you your class G....come on, embrace technology!


BTW, here are my class G...

Currently working on this bad boy (kitchen counter )... Carver M-4.0t (class G)

http://mdz.no-ip.org/public/carver.jpg










Here's the class G sub amp I'm currently using in my HT setup...

http://mdz.no-ip.org/public/bash.jpg










And, just so you don't think I'm a class B snob, here's the current state of my HT speaker bar project, using a class A LM1875...

http://mdz.no-ip.org/public/carver.jpg










-Mark [embracing technology...]


----------



## slomofo

MarkZ said:


> "Tubby sound" might indicate a frequency response difference of some sort. This could be a byproduct of either clipping or simple level matching (coherence with midbass drivers is a common cause of ~80Hz 'hooting', if that's what you're referring to). Or, if you were using onboard crossovers, that's always a FR culprit.
> 
> I don't know what "more control" sounds like.
> 
> At any rate, it's hard to do direct comparisons between amps without careful level matching. And by "careful", I mean hauling out the o-scope.


no onboard xovers used. running fully active signal with my 8443. no freq. changes were made as well. level matching is done through the head unit via attenuation control on my setup, the amps are turned all the way down, 8V is a really cool thing that way.


----------



## Niebur3

Not going to argue anymore...senseless.


----------



## smithee419

This will never get settled! If someone has comparisons to support something, someone else will have something to dissprove it. It's a no win situation. I think he should just go to his local kicker dealer and compare them side by side, that's if he was still gonna go kicker. Do some research for yourself and deciede what suits you best.


----------



## 14642

ashlar said:


> http://www.monstercable.com/mpc/stable/tech/A2412_Damping_Factor_Article.pdf


This, in fact, is the right explanation of damping factor and is the same one that I've posted all over this form several times. Link in the earlier post is just half the story. At least it's half, though. Amplifier damping factor shouldn't be a factor in anyone's decision to buy an amp for subs. If you're driving a full-range loudspeaker at and above its resonance, it might be, but only as it helps to identify the amp's output impedance.


----------



## thehatedguy

I'd say it would take more than an O-scope to match amps closely enough to get them sounding the same. Probably something like Audio Precision One would be needed to really see that is going on with an amp inorder to mod another one to make it measure (and sound) the same.


----------



## MarkZ

thehatedguy said:


> I'd say it would take more than an O-scope to match amps closely enough to get them sounding the same. Probably something like Audio Precision One would be needed to really see that is going on with an amp inorder to mod another one to make it measure (and sound) the same.


I was referring to using the o-scope to achieve simple gain matching and to detect clipping. It was in response to his observation that replacing the amps resulted in a noticeable difference. As you know, the test is not that easy. [Let alone the blind requirement...]

You can do far more complex measurements without breaking the bank by using matlab, or some other software solution. That's what I use at work, actually. And believe it or not, I just use a MobilePre for acquisition.


----------



## ALL4SQ

t3sn4f2 said:


> I don't get it.....
> 
> You said an amps with less parts should cost less, referring to a jl hd amp.
> 
> What I said was referring to them as well. They don't have less parts. They have more parts in order to be able to do things like be regulated and have adaptive rails and whatever else. So the brains that is needed to do those things is worth more then the AL you save from the increase in efficiency. That's where the extra cost comes from.
> 
> IOW, its not smaller because there are less parts in it, it's smaller because you need less heat sink due to increased efficiency. You pay extra for the complexity of the design.


Oh, I get what you meant now. Sorry 
For some reason I thought class D required fewer parts. I had that backwards.

Thanks


----------



## t3sn4f2

ALL4SQ said:


> Oh, I get what you meant now. Sorry
> *For some reason I thought class D required fewer parts*. I had that backwards.
> 
> Thanks


Maybe, maybe not. But aside from the class, all the other features would require more parts I imagine.


----------



## MarkZ

Parts are cheap. The big stuff -- rectifiers, switching transistors, output transistors, transformer, and most of all, heatsink, are the stuff that costs money. Small signal parts and regulation parts don't take up much space or produce much heat. I don't know why people are opposed to lots of parts. The lowest distortion designs are the ones with the most complex amplifier stages! Manufacturers don't add extra parts just for their health.


----------



## thehatedguy

I like even order distortion 

But people get too hung up on THD measurements. Who cares if the amp is .02% THD? Or .2, or even 2%? Your speakers are going to add so much more distortion that it really isn't going to matter if THD is in the lower half of the single digits. Well, it would if you listened to test tones...

I didn't know you could do those sorts of things in Matlab. That's pretty cool...and an asston cheaper than an AP1 system.


----------



## 14642

MarkZ said:


> I don't know why people are opposed to lots of parts.


Because there are two types of audiophiles--those that are scientifically inclined and those that are "Religulous" about the gear. 

As Isaac Newton wrote:

If it be said that we are not to determine what’s scripture & what not by our private judgements, I confesse it in places not controverted: but in disputable places I love to take up wth what I can best understand. Tis the temper of the hot and superstitious part of mankind in matters of religion ever to be fond of mysteries, & for that reason to like best what they understand the least.


----------



## MarkZ

thehatedguy said:


> I like even order distortion
> 
> But people get too hung up on THD measurements. Who cares if the amp is .02% THD? Or .2, or even 2%? Your speakers are going to add so much more distortion that it really isn't going to matter if THD is in the lower half of the single digits. Well, it would if you listened to test tones...


Yep. But for people chasing after every last percentage point, more parts are often required to make it to the next level. In Randy Slone's book, he presents a very complex input stage that has literally double the part count (it's a mirrored design) of an already complex input stage... all to get distortion values down from like .01% down to .001%, or something like that. A complete waste of time in a practical sense, but some people are into that. 



> I didn't know you could do those sorts of things in Matlab. That's pretty cool...and an asston cheaper than an AP1 system.


You can do just about anything in Matlab as far as measurement goes. The language is high-level enough for most people comfortable with programming to be able to do whatever they want. Their "simulink" software gives you real-time processing capabilities too. Speed is always a problem in Matlab, but not everything that we have to measure needs to be done in real-time. On that note, I still think a Matlab-based audio processing tool could rival console/audiomulch in a very big way. In fact, it could rival the entire VST framework...


----------



## ghostmechanic

Niebur3 said:


> Give me a break if you think the air temperature is that much different next to any amp...little lone different class D amps. If it is, we are not talking much at all.


You're fairly new to car audio huh? Apparently you've never felt the heat off of an Orion HCCA 250 running at 1ohm in bridged mode? Or an old Earthquake PA series amp running on 2ohm stereo? That is the main difference between class A/B & class D. Efficiency. The A/B loses a lot of power (close to 40% on some amps) to heat. Most class D's lose maybe 20% at worst. A true class A (not the old Soundstream's) are even worse as far as efficiency & heat. I'm not taking sides, I'm stating facts. I repair amplifiers on a personal/hobby level & read as much as I can about amplifier circuit designs. 

As far as the JL vs. Kicker... maybe, I've never owned either as far anything newer. I owned a Kicker amp way back when but every brand has changed since then. I can't see that much difference myself. A cheap Chinese amp is a cheap Chinese amp. From my perspective both are over priced crap. Both are relying on a brand recognition thing that was formed many years ago & fail to live up to it now. I've not owned a newer Soundstream (& I'm not a huge fan of the older stuff) but from experience of working on a few recently, they have better customer service than just about any brand out there besides Rockford Fosgate. Their service is at least as good. They'd be my recommendation as far as newer type amps.



Niebur3 said:


> I can agree with that....brand does make a huge difference. Please don't run the amp at 1 ohm....I don't car what the manufactures say it can do, way to close to a dead short and all good specs of the amp go right out the window. That could be a big reason why class D amps fail so much.


Wrong. You do realize that a speaker's impedence is not the same a resistive load right? And that the wire no matter what size it is will have some resistance in it? Again it all depends on the amp & what it's intended for. There are amps out there that have no issues with running a 1 ohm load all day. There are some that can't do it all day but can put out MASSIVE amounts of power into really insane impedences for short times for SPL type stuff.

As far as whomever has dimming lights... Do the Big 3 & use 1/0 or so wire for it. That's the FIRST thing that should be done before doing ANY car audio install that requires more than maybe just adding a small sub amp to a factory system. That wire the factory runs from the alternator to the battery is just barely adequate for the factory installed accessories. Trust me, if you've never done the upgrade, you will be amazed when you get it done. On the car I drive now, it even made my headlights noticeably brighter. But my battery is in the trunk too.


----------



## Niebur3

Not going to argue anymore...senseless.


----------



## Niebur3

Not going to argue anymore...senseless.


----------



## t3sn4f2

Niebur3 said:


> No, I'm not new...thanks for the insinuation. I've been serious in car audio since 1994. I guess the thing I've never gotten into was the huge amp and the boom crap. None of my class A/B sq systems have had heat issues because I don't try to run my amps at 1 or 1/2 ohm. At 4 ohm, it just doesn't seem to give me any problems, most amp not even that warm to the touch. I think your numbers and what the manufactures show are very generous regarding the efficiency of class D amps. I'm sure you would be very surprised. I understand the drain of a class A/B, but at 4 ohm, I bet it is not much more than your class D at 1 ohm. Sound Quality has always been the only thing I can about in car audio. I have very good hearing and maybe the confusion here is that I do run my amps at 4 ohm. I don't think the fact that I think there is a difference and I have experienced that difference, I am not embracing new technology. I am not a sheep, I do my own research and listen with my own ears. I am a skeptic until proven otherwise, but I also research and listen to more than car audio people. Most of the companies that make class D are ****ty companies that make ****ty amps and most of the high end companies don't bother with class D. I own a Pontiac Firebird Formula with the LS1 - I get good gas mileage because I don't floor it. *I don't have problems with my amps current draw and efficiency because I don't floor them.* Sometime new technology isn't always better, it can be cheaper and lower quality. When it is not, I embrace it. But do tell me that it there is a 10 or 20% efficiency difference between different amps that is greatly effect air temperature in a trunk. Maybe a couple of degrees, I doubt anything that would cause your carputer to melt down.


But amps are at their most efficient _when floored_.


----------



## Niebur3

t3sn4f2 said:


> But amps are at their most efficient _when floored_.


Not going to argue anymore...senseless.


----------



## MarkZ

Niebur3 said:


> No, I'm not new...thanks for the insinuation. I've been serious in car audio since 1994. I guess the thing I've never gotten into was the huge amp and the boom crap. None of my class A/B sq systems have had heat issues because I don't try to run my amps at 1 or 1/2 ohm. At 4 ohm, it just doesn't seem to give me any problems, most amp not even that warm to the touch.


I don't mean any offense by this, I really don't, but please avoid taking your own personal experiences and then applying the word "most" to those things. You really don't know about "most amps". I doubt you have access to "most amps", and I doubt you have much experience with doing anything to amps aside from using them. 

I'm glad that your amps don't get warm to the touch. But many many amps DO get hot, and in fact, many many amps are DESIGNED with certain temperature parameters in mind (and these temps are HOT). For example, back when I had my ESX Q1752 bridged on a 4 ohm load, it would get incredibly hot after, say, 30-45 minutes of listening. BTW, it's NEVER shut down on me. I use that configuration as an example because it's generally regarded as a "good" amp, and I wasn't running a 1 ohm load which you're so opposed to (which, by the way, class D inherently handles better than B ).

Anyways, my Zed Minilith doesn't get terribly hot. It's sitting next to the computer. My ESX Q1752 and Q1204 are behind a different panel, and the 1752 does get rather hot after extended use. I was having temperature issues with my computer earlier this summer, so not introducing the additional heat from those amplifiers is definitely having an impact. 

The fact is, and you may not be aware of this, but carputers and heat are mortal enemies. The car is a terrible environment for them! There have been threads upon threads upon threads (in this forum and in others) where people have been asking how to deal with the issue. Many people even go so far as to reroute their AC ducts to cool the computer!  Whether you want to admit it or not, these are very real issues. You asked earlier who's concerned with amplifier efficiency, and I answered that I am. Just because the answer doesn't serve your agenda doesn't mean that it's not a valid one.


----------



## MarkZ

Niebur3 said:


> Efficiency, yes...but current draw is at their all time high, which is what make light dim..the original mention of the efficiency problem. The whole point of more efficient amps is to reduce current draw. I am saying my 4 ohm loads reduce current draw more than your increased efficiency with class D.


There's just no logic to this statement. Class D is (almost always) more efficient than class B. Therefore, if you're delivering the same amount of power to the speaker in both situations, then the class D will draw less current. This is what efficiency means.

It makes no sense to me why you're comparing a big powerful class D to a less powerful class B and then claiming that the class B is somehow drawing less current. No ****, sherlock. It'll also draw less current than the class D if it's powered off too. Compare apples and apples here -- 100w from the class B amp vs. 100w from the class D amp... the class D amp will draw less current.


----------



## Niebur3

Not going to argue anymore...senseless.


----------



## MarkZ

Niebur3 said:


> And I agree to disagree but you people keep trying to convince me otherwise.


No, just because you say you "agree to disagree" doesn't give you carte blanche to spew the same nonsense to someone else. If you agreed to disagree, you wouldn't keep going on about how it makes no sense to you that a hot amp in a confined airspace can impact the temperature of something sharing that airspace. Or that your class A/B amp is drawing less current than a class D amp.

I'm sorry, but as long as you're gonna keep saying this sort of ****, expect other people to call you on it. The guy who responded to you told you he repairs amps for a living. If you opened up an amp, would you even know what you were looking at? Of course not. And you think you're qualified to have these sorts of discussions? Your "research" is ********. It's internet hearsay and industry myths. Learn something about how an amplifier works before you start trying to correct people who clearly know more than you. Have a nice day.


----------



## Niebur3

Not going to argue anymore...senseless.


----------



## MarkZ

Niebur3 said:


> Sorry, I didn't realize I was in the presence of greatness. I will, thanks for your comment . I'm just glad all don't feel the same as you do....epecially the ACTUAL people that design and build them. I'm out!


Well, given the massive takeoff in the class D market in recent years, it seems you're wrong about that too. Again.

Besides, why don't you leave THOSE people to make their own arguments. I'm sure they wouldn't appreciate your attempt at making their arguments for them. It's almost painful to watch.


----------



## Niebur3

MarkZ said:


> Well, given the massive takeoff in the class D market in recent years, it seems you're wrong about that too. Again.
> 
> Besides, why don't you leave THOSE people to make their own arguments. I'm sure they wouldn't appreciate your attempt at making their arguments for them. It's almost painful to watch.



Not going to argue anymore...senseless. Keep believing the crap coming out of your mouth.


----------



## WLDock

Niebur3 said:


> Not going to argue anymore...senseless.


Yeah, you guys should let this one go.....Because you know what will start up next????

SEALED vs. PORTED
SEALED OR PORTED vs. IFINITE BAFFLE
FIRING BACKWARDS vs. FORWARD
FIRING UP vs. DOWN
FIRING LEFT vs. RIGHT
FIRING AT EACH OTHER vs. FIRING TOWARDS THE BACK
STEREO BASS vs. MONO BASS
FAST 10" & 12" SUBS vs. SLOW 15" SUBS
CAR AUDIO SUBS vs. RAW DRIVER SUBS
PAPER CONE vs. POLY CONE
POLY CONE vs. ALUMINUM COME
ALUMINUM CONE vs. CARBON/KEVLAR
SINGLE LARGE DISPLACEMENT vs. MUTIPLE SMALLER DISPLACEMENT
SINGLE HIGH POWER HANDLING vs. MULTIPLE SMALLER POWER HANDLING
HIGH Qts. vs. LOW Qts
HIGH EFFICIENTCY/LOW POWER vs. LOW EFFICIENCY/ HIGH POWER
and on and on and on and on.......

The SQ debate NEVER ends so it is BEST to agree that it will NEVER end and END it!


----------



## ALL4SQ

Just Noticed ARC Audio has some decently priced fullrange Class D amps.

How can ARC sell there Fullrange Class D Four channel amp for $329 while the other brands are twice the price?

Might try these out in my Tow Rig.


----------



## ChrisB

WLDock said:


> Yeah, you guys should let this one go.....Because you know what will start up next????
> 
> SEALED vs. PORTED
> SEALED OR PORTED vs. IFINITE BAFFLE
> FIRING BACKWARDS vs. FORWARD
> FIRING UP vs. DOWN
> FIRING LEFT vs. RIGHT
> FIRING AT EACH OTHER vs. FIRING TOWARDS THE BACK
> STEREO BASS vs. MONO BASS
> FAST 10" & 12" SUBS vs. SLOW 15" SUBS
> CAR AUDIO SUBS vs. RAW DRIVER SUBS
> PAPER CONE vs. POLY CONE
> POLY CONE vs. ALUMINUM COME
> ALUMINUM CONE vs. CARBON/KEVLAR
> SINGLE LARGE DISPLACEMENT vs. MUTIPLE SMALLER DISPLACEMENT
> SINGLE HIGH POWER HANDLING vs. MULTIPLE SMALLER POWER HANDLING
> HIGH Qts. vs. LOW Qts
> HIGH EFFICIENTCY/LOW POWER vs. LOW EFFICIENCY/ HIGH POWER
> and on and on and on and on.......
> 
> The SQ debate NEVER ends so it is BEST to agree that it will NEVER end and END it!


What about the fact that the biggest obstacle to SQ in a car is the car itself? Also, when your AC goes out, and you are forced to drive for 3 hours with the windows down, all hopes for SQ are lost.


----------



## Oliver

Ever notice even with enough cotton in your ears . . . when you are driving 85 mph through Dallas . . . the only thing you can hear is the siren ?

Weird


----------



## 03blueSI

I have gotten over this debate long ago. i am running full range class D amps and I have had several Class A/B amps that sound worse than them. It is all about the quality of the equipment and the install not what topology it uses.

I have heard a few pure class A guitar amps that sound like absolute crap.


----------



## ghostmechanic

Mark Z., I never claimed to repair amps for a living. Only as a hobby. It helps pay for my rquipment. I buy broken, repair & then sell. Or fix for friends.

Niebur3, I never meant to argue with you. I apologize if you thought I was being an ass assuming you were a newbie. Well maybe not newbie but just not as old as I am. I've been into car audio since I was in high school back in the late '80s. Some amplifiers are designed to use a lower impedence. That's why the old Orion HCCA's have 4 times the power supply FETs & 4 times the output transistors that other amps in the same "power class" had back then. Hell the old Concept 97.1 or whatever the model designation is, was rated at .5 watt per channel at 4 ohms but was a monster of an amp. It made it's power at basically being shorted out. Same with today's equipment. There are amps that are designed for it.

BTW, I've never personally owned a class D amp in a car. My wife has because of the small size. I prefer MADE IN USA class A/B for the record. So I'm not biased or a class D lover. It's just a proven fact they are more efficient. That's one of the reasons the heatsinks are so small. Well the main reason. The other is the surface mount components used that take up less space. See that's another reason the older amps were so large. Not just needing the cooling but because surface mount hadn't become the norm for electronics. Another reason why I love those amps. I can work on them easier.

And also for the record, I like to run my amps at 2 ohms because I can use a smaller amp to do the same job & there is no sound quality difference. At least not to me. I may not have hearing that's as good as yours. I listen to music that most people would question why I would even care about sound quality & I like to keep it cranked up

I don't know anything about keeping a computer cool in a car. I have never used one. I guess I don't have a reason to carry a computer? I'm into sound quality so I don't really do MP3s.


----------



## AUDIO_BASSICS

comfy_shoes said:


> hi there I was wondering if looking for sq out of your sub woofer....wether going with a a/b or d class amp will make much of an audible difference. I am considering a kicker amp . I am curious to know wether the a/b zx400.2 bridged in mono or the zx400.1 class d will be a better choice. is there a percievable sound quality difference from anyones experience?


old school a/b is the way to go class d is a compromise


----------



## MarkZ

ghostmechanic said:


> Mark Z., I never claimed to repair amps for a living. Only as a hobby. It helps pay for my rquipment. I buy broken, repair & then sell. Or fix for friends.
> 
> Niebur3, I never meant to argue with you. I apologize if you thought I was being an ass assuming you were a newbie. Well maybe not newbie but just not as old as I am. I've been into car audio since I was in high school back in the late '80s. Some amplifiers are designed to use a lower impedence. That's why the old Orion HCCA's have 4 times the power supply FETs & 4 times the output transistors that other amps in the same "power class" had back then. Hell the old Concept 97.1 or whatever the model designation is, was rated at .5 watt per channel at 4 ohms but was a monster of an amp. It made it's power at basically being shorted out. Same with today's equipment. There are amps that are designed for it.
> 
> BTW, I've never personally owned a class D amp in a car. My wife has because of the small size. I prefer MADE IN USA class A/B for the record. So I'm not biased or a class D lover. It's just a proven fact they are more efficient. That's one of the reasons the heatsinks are so small. Well the main reason. The other is the surface mount components used that take up less space. See that's another reason the older amps were so large. Not just needing the cooling but because surface mount hadn't become the norm for electronics. Another reason why I love those amps. I can work on them easier.
> 
> And also for the record, I like to run my amps at 2 ohms because I can use a smaller amp to do the same job & there is no sound quality difference. At least not to me. I may not have hearing that's as good as yours. I listen to music that most people would question why I would even care about sound quality & I like to keep it cranked up
> 
> I don't know anything about keeping a computer cool in a car. I have never used one. I guess I don't have a reason to carry a computer? I'm into sound quality so I don't really do MP3s.


Computers can do flac too, you know.


----------



## t3sn4f2

MarkZ said:


> Computers can do flac too, you know.


and they don't have noisy transports.


----------



## KingDiamond

In theory A/B sounds better than Class D topology. I had a Memphis Class-D amp and switched to a PPI Class A/B with less power, and the bass was more defined out of my Image Dynamics IDQ10v2.

There's more to THD than audible distortion. It also plays a role in the fidelity of the audio being output from the amplifier. With more THD there are more harmonics and modulation/fluctuation introduced into the signal. At low volumes you wouldn't be able to tell the difference but at higher volumes playing music with a lot of dynamics you might be able to hear the difference if you know what to listen to. But considering today's music is highly compressed and dynamics are squashed, you probably won't hear the difference, especially in a subwoofer.

The fidelity of car audio to me is the sum of all of the components so I try to make sure every part is not contributing anything negative to the signal. So I stay with Class A/B for subwoofer use, just for "piece of mind" that my sub amp isn't reducing the all-important bottom-end of the audio.


----------



## t3sn4f2

KingDiamond said:


> *In theory A/B sounds better than Class D topology.* I had a Memphis Class-D amp and switched to a PPI Class A/B with less power, and the bass was more defined out of my Image Dynamics IDQ10v2.
> 
> There's more to THD than audible distortion. It also plays a role in the fidelity of the audio being output from the amplifier. With more THD there are more harmonics and modulation/fluctuation introduced into the signal. At low volumes you wouldn't be able to tell the difference but at higher volumes playing music with a lot of dynamics you might be able to hear the difference if you know what to listen to. But considering today's music is highly compressed and dynamics are squashed, you probably won't hear the difference, especially in a subwoofer.
> 
> The fidelity of car audio to me is the sum of all of the components so I try to make sure every part is not contributing anything negative to the signal. So I stay with Class A/B for subwoofer use, just for "piece of mind" that my sub amp isn't reducing the all-important bottom-end of the audio.


No it doesn't.


----------



## ashlar

On a slightly different take, here is what Mark Eldridge had to say on the subject.

*Ahhh... The amp challenge is resurfacing yet again. Another generation of car audio fanatics to enlighten! 

Seriously guys and gals, no one has ever (that's EVER!!!) proven that they can hear the difference between amplifiers under the criteria in which the test is administered. I've been through it many times, and even thought I heard a significant difference once. That was until I took it again and proved myself wrong. 

The test parameters are totally on the up and up, and there is no hidden capability to slant the results. Every part of the test set up is plainly visible. Last time I saw it, even the circuit boards were visible. The entire test is designed to determine if there are audible differences between two amplifier designs under normal, undistorted listening conditions. 

How many people have taken it now, Richard? Several thousand?

Come on everybody. Somebody needs to take RCs money! He's been winning this challenge for way too long now. 

C-ya!
--------------------
Mark Eldridge*


----------



## Mooble

Forget the class D amps if you're that concerned about SQ and get a class G/H like the Clarion DPX. It has lots of power, high damping factor, and very efficient. I went from a high voltage A/B amp to a DPX11551 with no loss in SQ on a Morel Ultimo.


----------



## Oliver

Some can't even hear distortion of 10% in that range.

Grab a couple of the Focal 33's and a Zapco 9.0 CK , if your ears are really good


----------



## 89grand

I can't tell that my cheap Sony XM-4S in my Jeep is full range class D, there is no noticeable distortion or noise. I heard no difference between my old class D JBL GTO-600.1 and my old PPI A600.2 either, but I'm sure some here could easily tell.

Maybe I'm so old I'm nearly deaf.

A few people have heard my Jeep, and they're always surprised the little Tang Band 6.5" sub has as much bass as it does, but no one has ever said "You're running class D right, I can tell".


----------



## Niebur3

ashlar said:


> On a slightly different take, here is what Mark Eldridge had to say on the subject.
> 
> *Ahhh... The amp challenge is resurfacing yet again. Another generation of car audio fanatics to enlighten!
> 
> Seriously guys and gals, no one has ever (that's EVER!!!) proven that they can hear the difference between amplifiers under the criteria in which the test is administered. I've been through it many times, and even thought I heard a significant difference once. That was until I took it again and proved myself wrong.
> 
> The test parameters are totally on the up and up, and there is no hidden capability to slant the results. Every part of the test set up is plainly visible. Last time I saw it, even the circuit boards were visible. The entire test is designed to determine if there are audible differences between two amplifier designs under normal, undistorted listening conditions.
> 
> How many people have taken it now, Richard? Several thousand?
> 
> Come on everybody. Somebody needs to take RCs money! He's been winning this challenge for way too long now.
> 
> C-ya!
> --------------------
> Mark Eldridge*


I will NOT discuss at all my opinion on Class A/B vs D because I can see now it is an impossible argument. 

But I would like to say that NO one will ever win the Richard Clark challenge. To understand why, you would have to understand statistics. Read this article about double blind testing written in 1985, before Richard came up with this challenge. 

Stereophile: The Highs & Lows of Double-Blind Testing 

Clark by making you get 100% right will never have to pay out. So basically if I hear a difference 11 of 12 times, he wins. He will not keep or release the results and show how close anyone has come to this and states that many people have passed the 1st round, but not the second round. A 95% level of significance or confidence in any blind study (regardless of the type of study) requires only 12 of 16 correct. It is almost like the whole vegas and betting thing...on the surface you think the probability is 50/50 in something, not realizing that statistics come into play and they always have the advantage. It has been many years since I took statistics so I wish I understood this all better but I can say why would burr-brown make different op-amps and so on and so forth about the amp internals if it didn't make amps sound different.


----------



## ca90ss

Niebur3 said:


> Clark by making you get 100% right will never have to pay out.


If the differences were as great as some here seem to believe then getting 100% should be no problem.


----------



## Niebur3

ca90ss said:


> If the differences were as great as some here seem to believe then getting 100% should be no problem.


I see your point, but all the subtle differences as decay, ambiance, depth, width may be harder to pick out as the test goes on and ear fatigue sets in. Just guessing - but maybe it has something to do with you being able to remember such subtle differences that are not tonal in nature - again...just a guess...no need to name call or assume anything about me. 

I would think it would be much greater also, however. This all is somewhat confusing, because I understand no one has passed the test. I understand that statistics say no one can, but if you show me something black and white, I can tell you which is which 100% of the time. I have heard the difference so I believe there is one, but then I come back to this test. Why is it not more black and white? I just can't even imagine a $50,000 class A professional best of the best can compete with a Walmart special with only an eq being in the mix. Why different op-amps, why different caps, why different manufacturers?


----------



## AAAAAAA

89grand said:


> I can't tell that my cheap Sony XM-4S in my Jeep is full range class D, there is no noticeable distortion or noise. I heard no difference between my old class D JBL GTO-600.1 and my old PPI A600.2 either, but I'm sure some here could easily tell.
> 
> Maybe I'm so old I'm nearly deaf.
> 
> A few people have heard my Jeep, and they're always surprised the little Tang Band 6.5" sub has as much bass as it does, but no one has ever said "You're running class D right, I can tell".


The sony xm-4s is not class D just FYI. Class AB.


----------



## chad

Decay, ambience, and depth.... in a subwoofer... that's basically pressurising a cabin and flexing metal.


----------



## Niebur3

chad said:


> Decay, ambience, and depth.... in a subwoofer... that's basically pressurising a cabin and flexing metal.


I am now referring to more than sub frequencies.


----------



## Blu

ca90ss said:


> If the differences were as great as some here seem to believe then getting 100% should be no problem.


IIRC - Was this not essentially the core rationale behind Richard Clark's challenge in the first place?


----------



## 89grand

AAAAAAA said:


> The sony xm-4s is not class D just FYI. Class AB.


It's class D.

I think you were right before, when you wrote this a few years back:

Sony XM-4S full range class D review - Canadian Car Audio - Canada’s #1 Car Audio Forum

Crutchfield also states class D

Sony XM-4S 50W x 4 Thin Car Amp

It's too small and runs too cool to be class A/B. It's without a doubt class D.


----------



## MarkZ

89grand said:


> It's too small and runs too cool to be class A/B. It's without a doubt class D.


Small and cool? Screw class D. I like big and hot. Like how you prefer your women.


----------



## slomofo

Blu said:


> IIRC - Was this not essentially the core rationale behind Richard Clark's challenge in the first place?


the rationale is to never pay out and the statistics are in his favor. it's like eating thanksgiving dinner all day. after a while, everything starts to blend together. sorry, i'm not drinking the kool-aid. i have a lot of respect for what RC did for publicizing car audio (note, i said publicizing since speaker works did the majority of the work on the grand national) but i think he's just a guy with a lot of test equipment. again, the mind is much farther advanced than any of this worlds computers


----------



## MarkZ

I'm pretty sure that it wouldn't be too difficult to detect the difference between the stock Bose tweeter in my last car and a Morel Supremo 100% of the time.

I'm also pretty sure that I could detect the difference between my audio system in my little Volvo and the same system in a Ford Expedition 100% of the time.

This tells us that the differences in the acoustical realm are a lot bigger than the differences in the electrical realm. This, of course, shouldn't be news to anyone. We've known this for a long time based on the measurement of sound. It's rather easy to do, too, if you've got the right software and know how to use it.

RC's challenge is a tough one to pass, no question. And although it's clearly NOT the best way to approach the question "Does amp A sound differently from amp B?", I think it does serve to reinforce the fact that any potential differences between amplifiers are so small that we can't even pick out the difference between $1000 amps and $100 amps 100% of the time. That has to impact our attitudes towards where we direct our time and our money, doesn't it? I mean, if we acknowledge that the vehicle's interior, and speaker placement, and the speakers themselves have such a big impact on the end result, are we all truly doing everything in our power to optimize those things before we start worrying about whether or not the Sinfoni amp is going to sound better than the Alpine amp?


----------



## 14642

MarkZ said:


> I'm pretty sure that it wouldn't be too difficult to detect the difference between the stock Bose tweeter in my last car and a Morel Supremo 100% of the time.
> 
> I'm also pretty sure that I could detect the difference between my audio system in my little Volvo and the same system in a Ford Expedition 100% of the time.
> 
> This tells us that the differences in the acoustical realm are a lot bigger than the differences in the electrical realm. This, of course, shouldn't be news to anyone. We've known this for a long time based on the measurement of sound. It's rather easy to do, too, if you've got the right software and know how to use it.
> 
> RC's challenge is a tough one to pass, no question. And although it's clearly NOT the best way to approach the question "Does amp A sound differently from amp B?", I think it does serve to reinforce the fact that any potential differences between amplifiers are so small that we can't even pick out the difference between $1000 amps and $100 amps 100% of the time. That has to impact our attitudes towards where we direct our time and our money, doesn't it? I mean, if we acknowledge that the vehicle's interior, and speaker placement, and the speakers themselves have such a big impact on the end result, are we all truly doing everything in our power to optimize those things before we start worrying about whether or not the Sinfoni amp is going to sound better than the Alpine amp?


 
Right. Spend the money on pickles because the ketchup all tastes the same.


----------



## cubdenno

Andy Wehmeyer said:


> Right. Spend the money on pickles because the ketchup all tastes the same.


But wait!! Do I get bread and butter or dill pickles???


----------



## Niebur3

MarkZ said:


> I'm pretty sure that it wouldn't be too difficult to detect the difference between the stock Bose tweeter in my last car and a Morel Supremo 100% of the time.
> 
> I'm also pretty sure that I could detect the difference between my audio system in my little Volvo and the same system in a Ford Expedition 100% of the time.
> 
> This tells us that the differences in the acoustical realm are a lot bigger than the differences in the electrical realm. This, of course, shouldn't be news to anyone. We've known this for a long time based on the measurement of sound. It's rather easy to do, too, if you've got the right software and know how to use it.
> 
> RC's challenge is a tough one to pass, no question. And although it's clearly NOT the best way to approach the question "Does amp A sound differently from amp B?", I think it does serve to reinforce the fact that any potential differences between amplifiers are so small that we can't even pick out the difference between $1000 amps and $100 amps 100% of the time. That has to impact our attitudes towards where we direct our time and our money, doesn't it? I mean, if we acknowledge that the vehicle's interior, and speaker placement, and the speakers themselves have such a big impact on the end result, are we all truly doing everything in our power to optimize those things before we start worrying about whether or not the Sinfoni amp is going to sound better than the Alpine amp?


I have found it...a reasonable argument to why amps sound different. Richard Clark is very explicit that the amps need to stay below the level of clipping in his rules. Has anyone ever asked him why it is so important to stay below the level of hard or even soft clipping? Read this article.

Amplifier Sound - What Are The Influences?

It discusses how "all amps sound the same" and it confirm that it is quite probable that they do in a test environment, but yet sound greatly different in the real world. He states that one of the things that greatly impacts the sound of amps is clipping. We all think of clipping as hard clipping that we set our levels below, which we can still exceed with dynamic music we listen to. He also refers to "soft" clipping that is almost unavoidable (and measurable with the right instruments for all you prove it buffs) at normal listening levels and that this occurs more so than we ever have thought in the past. He states that amps react vastly different when this clipping occurs and therefore 2 different amps would be easily noticeable (you would get the test right 100% of the time). 

*Here are some exerts:

"For example; It is rare that testing is done on an amplifier's clipping performance - how the amp recovers from a brief transient overload. I have stated elsewhere that a hi-fi amplifier should never clip in normal usage - nice try, but it IS going to happen, and often is more common than we might think."

"Were these two amps compared in a double blind test (avoiding clipping), it is probable that no-one would be able to tell the difference. Advance the level so that transients started clipping, and a fence post would be able to hear the difference between them. What terms would describe the sound? I have no idea. The sound might be "smeared" due to the loss of detail during the recovery time of the IC amp. Imaging might suffer as well, since much of the signal that provides directional cues would be lost for periods of time."

How can one amplifier's clipping distortion sound different from that of another? Most of the hi-fi fraternity will tend to think that clipping is undesirable in any form at any time. While this is undeniably true, many of the amps used in a typical high end setup will be found to be clipping during normal programme sessions. I'm not referring to gross overload - this is quite unmistakable and invariably sounds awful - regardless of the amplifier.

There are subtle differences between the way amplifiers clip, that can make a very great impact on the sound. Valve amps are the most respectable of all, having a "soft" clipping characteristic which is comparatively unobtrusive. Low feedback Class-A amplifiers are next, with slightly more "edge", but otherwise are usually free from any really nasty additions to the overall sound.

"Then there are the myriad of Class-AB discrete amps. Most of these (but by no means all) are reasonably well behaved, and while the clipping is "hard" it does not have significant overhang - this is to say that once the output signal is lower than the supply voltage again it just carries on as normal. This is the ideal case - when any amp clips, it should add no more nastiness to the sound than is absolutely necessary. Clipping refers to the fact that when the instantaneous value of output signal attempts to exceed the amplifier's power supply voltage, it simply stops, because it cannot be greater than the supply. We know it must stop, but what is of interest is how it stops, and what the amplifier does in the brief period during and immediately after the clipping has occurred."

"I think that no review of any amplifier should ever be performed without some method of indicating that the amp is clipping (or is subject to some other form of signal impairment), and this can be added to the reviewer's notes - along the lines of:

"This amplifier was flawless when kept below clipping (or as long as the SIM failed to show any noticeable impairment), but even the smallest amount of overload caused the amp to sound very hard. Transparency was completely lost, imaging was impaired badly, and it created listener fatigue very quickly.""*

This has to at least explain some things, how some people can hear and some can't and it raises some doubt and maybe a slight kink in the armor of "they all sound the same". We all listen in the "real world", not a test environment.


----------



## Niebur3

Blu said:


> IIRC - Was this not essentially the core rationale behind Richard Clark's challenge in the first place?


So, including the fact of ear fatigue, if I get 23 of 24 (according to his rules, you need to correctly identify 12 of 12 two times) I fail the test. To me, 23 of 24 would indicate the basic reason for the test in the first place, that you can tell 2 amps apart. I can get 96% right and fail...aren't you glad he was not your teacher in school. He says there are people that have passed the 1st round and failed the 2nd....ear fatigue??? He will never divulge the results, just that no one has passed....why?


----------



## ChrisB

You do have a point because some of the budget Class D amplifiers sound like garbage when they reach the clipping point. Last year at this time I watched a friend of mine perform a test with a Hifonics BXi 1606d and that bad boy would go from a nice, pretty, ocean like wave to a saw tooth square HARD and FAST!

That was really bad compared to a class ab amplifier that clipped nice and slow.


----------



## Niebur3

06BLMUSTANGGT said:


> You do have a point because some of the budget Class D amplifiers sound like garbage when they reach the clipping point. Last year at this time I watched a friend of mine perform a test with a Hifonics BXi 1606d and that bad boy would go from a nice, pretty, ocean like wave to a saw tooth square HARD and FAST!
> 
> That was really bad compared to a class ab amplifier that clipped nice and slow.


Which would lead to the next question regarding the clipping rate and recovery differences between class A/B and class D, leading to an audible sq difference.


----------



## MarkZ

Niebur3 said:


> This has to at least explain some things, how some people can hear and some can't and it raises some doubt and maybe a slight kink in the armor of "they all sound the same". We all listen in the "real world", not a test environment.


You're absolutely right. But there isn't a soul in this forum who believes that all amps, when driven into clipping, will sound the same. That has never been the argument. The argument can be boiled down to three questions:

1) What aspects of audio amplifiers influence the sound? - ie. FR, THD, IMD, S/N, Damping, Clipping behavior, etc?
2) Are these measurable parameters?
3) How do we overcome these inherent problems?

Clark's test aims to address the first and second problems. As I said earlier in the thread, by virtue of setting up the conditions he's set up, he's ACKNOWLEDGING that amplifiers can sound different. By offering to EQ them, he's admitted that there are potentially FR differences. By eliminating noise issues, he's admitted that there are S/N issues. By insisting that the test is performed in a double blind environment, he implies that prior knowledge has an impact on perception.

These are all valid reasons to choose one amp over the other -- the one with the better FR, the one with the lower S/N, the one that makes you feel good owning! That's what it's all about, after all.

HOWEVER...

By showing that these factors are easily and cheaply correctable by other modifications, like EQing for example, then it seriously calls into question the rationale behind spending thousands of dollars for something that can be achieved for hundreds of dollars (or less).

The question isn't "Do two amps sound the same?" The question is "Can two amps be made to sound the same?" There's a big difference.

As for the clipping issue... How do you solve it? Ok, amplifier A clips more pleasantly than amplifier B. But amplifier C doesn't clip it all (it's a higher power model). Which one do you pick? More to the point, do you run the McIntosh 50w amp that clips beautifully, or do you run the Alphasonik 300w that isn't going to clip at all? Most people would pick the McIntosh. After all, it's the "better sounding" brand.


----------



## t3sn4f2

Niebur3 said:


> "Were these two amps compared in a double blind test (avoiding clipping), it is probable that no-one would be able to tell the difference. Advance the level so that transients started clipping, and a fence post would be able to hear the difference between them. What terms would describe the sound? I have no idea. The sound might be "smeared" due to the loss of detail during the recovery time of the IC amp. Imaging might suffer as well, since much of the signal that provides directional cues would be lost for periods of time."
> 
> 
> "This amplifier was flawless when kept below clipping (or as long as the SIM failed to show any noticeable impairment), but even the smallest amount of overload caused the amp to sound very hard. Transparency was completely lost, imaging was impaired badly, and it created listener fatigue very quickly.""[/I][/B]
> 
> This has to at least explain some things, how some people can hear and some can't and it raises some doubt and maybe a slight kink in the armor of "they all sound the same". We all listen in the "real world", not a test environment.


Page 2:

"Test 2 and 7----in this test the amps are driven *6db* into clipping. Since *6db* represents a *power level of 4:1* this means a *100 watt amp *would be attempting to produce a signal that would require a *400 watts amp *if the signal were to remain unclipped. *Even so it is rare that clipping at this level is audible*.


----------



## ChrisB

MarkZ said:


> As for the clipping issue... *How do you solve it?* Ok, amplifier A clips more pleasantly than amplifier B. But amplifier C doesn't clip it all (it's a higher power model). Which one do you pick? More to the point, do you run the McIntosh 50w amp that clips beautifully, or do you run the Alphasonik 300w that isn't going to clip at all? Most people would pick the McIntosh. After all, it's the "better sounding" brand.


When it came to budget brands, I started to recommend that my friends get the next model up with regards to the Hifonics Brutus series. For example, if they only needed the power offered by the BXi 12xxd, I would tell them to get the BXi 16xxd. To date, they liked my advice and no one has complained.

I was told the BXi xx08 and xx10 series have improved and will actually produce very close to rated unclipped power BUT I have have yet to see one on a test bench with an oscilloscope. Until then, I still recommend that they get the next model up if they must run the budget class D amplifier.


----------



## Niebur3

MarkZ said:


> You're absolutely right. But there isn't a soul in this forum who believes that all amps, when driven into clipping, will sound the same. That has never been the argument. The argument can be boiled down to three questions:
> 
> 1) What aspects of audio amplifiers influence the sound? - ie. FR, THD, IMD, S/N, Damping, Clipping behavior, etc?
> 2) Are these measurable parameters?
> 3) How do we overcome these inherent problems?
> 
> *If this is true that nobody on the forum believes that, when why are we recommending to people that they buy whatever because they all sound the same? Are they installing them in their car or a test lab in the same factor as Richard Clark (where people has still been able to hear differences)? Should we not be recommending the best sounding amp under normal listening conditions, in which the signal will be even slightly clipped under normal listening conditions?*
> 
> Clark's test aims to address the first and second problems. As I said earlier in the thread, by virtue of setting up the conditions he's set up, he's ACKNOWLEDGING that amplifiers can sound different. By offering to EQ them, he's admitted that there are potentially FR differences. By eliminating noise issues, he's admitted that there are S/N issues. By insisting that the test is performed in a double blind environment, he implies that prior knowledge has an impact on perception.
> 
> *So, the argument is if I take a Kia Rio vs any Lamborghini and I restrict the vehicle and environment they will post identical lap times around a track. Which would you choose for the real world though assuming you wanted a high performance vehicle and could afford either?*
> 
> These are all valid reasons to choose one amp over the other -- the one with the better FR, the one with the lower S/N, the one that makes you feel good owning! That's what it's all about, after all.
> 
> HOWEVER...
> 
> By showing that these factors are easily and cheaply correctable by other modifications, like EQing for example, then it seriously calls into question the rationale behind spending thousands of dollars for something that can be achieved for hundreds of dollars (or less).
> 
> *Because again, normal listening levels will lead to at least some clipping.*
> 
> The question isn't "Do two amps sound the same?" The question is "Can two amps be made to sound the same?" There's a big difference.
> 
> As for the clipping issue... How do you solve it? Ok, amplifier A clips more pleasantly than amplifier B. But amplifier C doesn't clip it all (it's a higher power model). Which one do you pick? More to the point, do you run the McIntosh 50w amp that clips beautifully, or do you run the Alphasonik 300w that isn't going to clip at all? Most people would pick the McIntosh. After all, it's the "better sounding" brand.


*Has the clipping been measured on the Alphasonik? How do we know it is not clipping. Again, most cheap amps are rated at max power which they will never be able to achieve, where the Mac is rated as continuous. I would challenge that the Alphasonik rated at 300 watts clips much faster and harder than the McIntosh rated at 50 watts.*


----------



## 89grand

The ONLY reason I would assume the McIntosh clips softer than an Alphasonic is because they have that "Power Guard" circuit. Other wise, I wouldn't know, but I wouldn't take a guess just because of the name.

I've run PPI Art series amps which many people claim are one of the best amps ever made. Compared to other amps I've owned like JBL, I didn't see any difference in their behavior, whether loafing along or ran hard into clipping. They acted the same to me, even though many here would suggest the PPI's are much better than JBL, I didn't hear a difference between the two.


----------



## MarkZ

Niebur3 said:


> *Has the clipping been measured on the Alphasonik? How do we know it is not clipping. Again, most cheap amps are rated at max power which they will never be able to achieve, where the Mac is rated as continuous. I would challenge that the Alphasonik rated at 300 watts clips much faster and harder than the McIntosh rated at 50 watts.*


Haha, ok that wasn't really my point. I made the assumption that the 300w Alphasonik was actually 300 watts. Actually, I don't think Alphasonik ever made an amp that big. They had a long multichannel one back in the day, but that might have been only 150w per channel. But they were pretty accurately rated.

89grand, I forgot all about power guard. <sigh>

Ok guys, I did a crappy job of choosing brands to use as examples. Hopefully you understand my point anyway. You can either choose to defeat the clipping problem with an amp that clips more graciously, or with an amp that won't clip at all.


----------



## 89grand

I understood your point. I just mentioned the power guard as the only reason it would clip softer. In fact, it sort of proves your point, because if the McIntosh was so much better and clipped so much softer it wouldn't need the power guard circuit in the first place I wouldn't think.


----------



## Brian10962001

For what it's worth I have owned 2 class D amps, a Kicker 600.1 from probably 03 or so and a Lanzar Opti 1000D. Both of these amps are now dead and gone. I still have my entire stable of old school Rockford A/B amps. In all honesty I have only killed one of these and that was my fault for getting the pos neg flipped around when I built an amp rack. Did the class D amps sound better or worse? No not really, and my girlfriends class T Blaupunkt amp doesn't sound any different than one of my Punch 500.2's or the Punch 150 25 to life I have ran her subs off of. I have been looking to give class D a chance again in the form of a Audiopipe 1500 watt mono amp but oddly enough I read an SPL competitors comments that they sounded "muddy" we'll see I suppose.


----------



## Niebur3

89grand said:


> I understood your point. I just mentioned the power guard as the only reason it would clip softer. In fact, it sort of proves your point, because if the McIntosh was so much better and clipped so much softer it wouldn't need the power guard circuit in the first place I wouldn't think.


The power guard was for those hard clipping instances. Soft clipping is happening quite regularly at normal listening levels. Music is dynamic. All this proves is that McIntosh put a guard in place to stop the speakers from receiving the hard clipped signal signal that damages speakers. Is soft clipping audible? I would ask Richard Clark as he will not allow the amps to clip at all with $10,000 on the line...I think he answered that question. Again to some degree I think your hearing, speakers and the rest of your system have something to do with that. You may not be able to point out "hey, it just clipped right there, and there and there....but you may notice that the exact passage played on another amp sounded more smooth with better clarity.


----------



## ashlar

Niebur3 said:


> All this proves is that McIntosh put a guard in place to stop the speakers from receiving the hard clipped signal signal that damages speakers.


Another audio myth.


----------



## chad

ashlar said:


> Another audio myth.


word


----------



## t3sn4f2

ashlar said:


> Another audio myth.


x2, I would think it was implemented to protect the amp and increase it's life. 

Piooner PRS amps have a simular circuit.


----------



## t3sn4f2

A question. I haven't set up a system in a long time and I can't recall this.

Do you _need_ to over drive an amp into clipping, say a 75 watt amp on a 7" mid bass, in order to overcome the background noise in a car? Essentially making it act like a dynamic compressor and bringing up the overall volume to a needed level. 

Will the gain structure be fine if at max head unit volume the amp puts out it's rated output and no more? Or will the sound be too low on normal crest factor songs even at max head unit setting? 

How about a 300 watt amp on a 7" mid bass? Will the amp then have enough gain to not need to be overdriven and yet be loud enough over all with a dynamic track?


----------



## Niebur3

t3sn4f2 said:


> A question. I haven't set up a system in a long time and I can't recall this.
> 
> Do you _need_ to over drive an amp into clipping, say a 75 watt amp on a 7" mid bass, in order to overcome the background noise in a car? Essentially making it act like a dynamic compressor and bringing up the overall volume to a needed level.
> 
> Will the gain structure be fine if at max head unit volume the amp puts out it's rated output and no more? Or will the sound be too low on normal crest factor songs even at max head unit setting?
> 
> How about a 300 watt amp on a 7" mid bass? Will the amp then have enough gain to not need to be overdriven and yet be loud enough over all with a dynamic track?


But you are assuming that Dynamics passages in the music will never cause it to even soft clip. Again, just call Richard Clark and ask him to do the test with his money on the line allowing even a fraction of clipping and see what he says. And again, if everyone on this forum knows this about amps, then why do we keep bringing up the argument when the amp will be used in the real world environment and WILL clip. And finally, people DID hear difference even with a non-clipped signal in Richard Clarks test, just couldn't name 24 out of 24...if you named 23 of 24 right, you faild...but does that mean there is no difference even in a non clipped signal and therefore why will he not keep results and publish them? The difference may be subtle with no clipping but great with clipping.


----------



## t3sn4f2

Niebur3 said:


> But you are assuming that Dynamics passages in the music will never cause it to even soft clip. Again, just call Richard Clark and ask him to do the test with his money on the line allowing even a fraction of clipping and see what he says. And again, if everyone on this forum knows this about amps, then why do we keep bringing up the argument when the amp will be used in the real world environment and WILL clip. And finally, people DID hear difference even with a non-clipped signal in Richard Clarks test, just couldn't name 24 out of 24...if you named 23 of 24 right, you faild...but does that mean there is no difference even in a non clipped signal and therefore why will he not keep results and publish them? The difference may be subtle with no clipping but great with clipping.


An amp rated and set up to put out no more then 300 watts into 4 ohms, from 20Hz-20kHz, at *.03%THD *with a *sine wave *is soft clipping huh? :laugh:


----------



## ErinH

I’m willing to bet that the large majority of people here (who know how to set up a system) never come close to driving their amp’s output (not risking what you do on the input side) to clipping. It’s nebulous here, imo. 

If you’re getting in the car and cranking the output to a clipped signal with MUSIC, then you’ve got bigger fish to fry (no pun intended) than whether or not your amp sounds different than another.


----------



## Mooble

bikinpunk said:


> If you’re getting in the car and cranking the output to a clipped signal with MUSIC, then you’ve got bigger fish to fry (no pun intended) than whether or not your amp sounds different than another.


I completely disagree. I can very easily clip at 150w per 6.5" woofer. I do frequently too. I admit that I do like it loud from time to time, but there's a world of difference between clipping a 150w kickdrum and 150w vocals. I can put 150w on some vocal passages that are not even loud enough to overcome road noise. Fortunately my amp doesn't sound horrible when clipped so I can live with it, but some other amps sound absolutely intolerable when clipping.


----------



## 94VG30DE

bikinpunk said:


> I’m willing to bet that the large majority of people here (who know how to set up a system) never come close to driving their amp’s output (not risking what you do on the input side) to clipping. It’s nebulous here, imo.
> 
> If you’re getting in the car and cranking the output to a clipped signal with MUSIC, then you’ve got bigger fish to fry (no pun intended) than whether or not your amp sounds different than another.


I would have to echo this. Maybe in a live sound situation you would have more common clipping and be ok with it, but I can't see most of us in the car-audio realm pushing amps to clipping for any length of time. It just isn't necessary when you are so close to the speaker and wattage is so cheap. There is no point in listening to music at reference volume everywhere I drive. So yes, maybe, and that is a BIG MAYBE, you might have an issue when auditioning the amp at full output. But any other time that becomes a mute (sic) point.


----------



## t3sn4f2

Mooble said:


> I completely disagree. I can very easily clip at 150w per 6.5" woofer. I do frequently too. I admit that I do like it loud from time to time, but there's a world of difference between clipping a 150w kickdrum and 150w vocals. I can put 150w on some vocal passages that are not even loud enough to overcome road noise. Fortunately my amp doesn't sound horrible when clipped so I can live with it, but some other amps sound absolutely intolerable when clipping.


I assume this is with quality music that does not come compressed and clipped correct? So that would mean that you are clipping the amp but what is clipping it is not the average and majority of the music content but a brief peak that is easily 12dB above the average.

You amp clips pleasantly or you simply aren't able to hear the degradation of a brief clipped peak?


----------



## ErinH

Mooble said:


> I completely disagree. I can very easily clip at 150w per 6.5" woofer. I do frequently too. I admit that I do like it loud from time to time, but there's a world of difference between clipping a 150w kickdrum and 150w vocals. I can put 150w on some vocal passages that are not even loud enough to overcome road noise. Fortunately my amp doesn't sound horrible when clipped so I can live with it, but some other amps sound absolutely intolerable when clipping.



How do you typically set your amps up?
How do you evaluate the signal chain from start to finish?




I realize that occasional clipping is likely to happen, but given how many times I’ve read threads, talked with people and benched my own gear, in addition to tweaking it after benching it from signal to final output, I can say with about 99% confidence that I rarely ever reach a clipped output on my setup. Just given the way I set the system up. 
The others who follow the method I use probably would say the same. If you’re clipping your amp enough for you to hear it, you need to look at an amp with more clean output or you’re going to have issues. 
I’m talking music here… not test tones or rap music trying to impress friends. I just don’t see people full out clipping their amps’ output while listening to music. Even WOT I don’t have any audible clipping for minutes at a time.


----------



## Niebur3

t3sn4f2 said:


> An amp rated and set up to put out no more then 300 watts into 4 ohms, from 20Hz-20kHz, at *.03%THD *with a *sine wave *is soft clipping huh? :laugh:





bikinpunk said:


> I’m willing to bet that the large majority of people here (who know how to set up a system) never come close to driving their amp’s output (not risking what you do on the input side) to clipping. It’s nebulous here, imo.
> 
> If you’re getting in the car and cranking the output to a clipped signal with MUSIC, then you’ve got bigger fish to fry (no pun intended) than whether or not your amp sounds different than another.



Ok, lets say someone set there system up so that no clipping what so ever occurs (hopefully in a vehicle, they can still hear it because they would have to set so the most dramatic of passages in the music they are listening to, never clips - especially since this discussion has talked about the 2 and 1 ohm loads most people are using - which only drives it closer...again, not talking about major clipping, but the soft clipping that happens in extremely short waves), then you are saying that just because someone is unable to identify 24 or 24 (which Richard Clark requires to pass his test) there is absolutely without a doubt NO difference between amps (again keeping in mind he will NOT publish how you did, only that you failed even though some have passed the 1st round). 

Do any of you realize that if you teachers in school required you to always get 100% right on every piece of homework and test to pass, you would still to this day be in grade school.

Are you also saying the all OpAmps sound the same since the are a part of the amp? That Burr-Brown is full of ****? 

I am sure almost 100% of the seasoned people here can set their system so when they turn it up, it does not HARD clip. Many many even know that they could be SOFT clipping on a regular basis? We set up our systems not to hard clip using sign waves or other various methods....sign waves are NOT dynamics music.

McIntosh and Tru may have extremely subtle differences, but you really think either Mac and Tru compared against Quantum would yield NO sound difference? Seriously?


----------



## 94VG30DE

Niebur3 said:


> I am sure almost 100% of the seasoned people here can set their system so when they turn it up, it does not HARD clip. Many many even know that they could be SOFT clipping on a regular basis? We set up our systems not to hard clip using sign waves or other various methods....sign waves are NOT dynamics music.


I thought that was the whole point of setting up gain structure using 0dB test tones? The idea was that 0dB was the "hottest" signal that could ever come across the source, so that no matter how "dynamic" your music was, you could never go over the ceiling that was already set up using the max possible voltage your source could ever send.


----------



## ErinH

Apples to apples.

Are you talking about clipping a 50w amp, or a 150w amp? 
Things that all determine gain are sensitivity, location, purpose, noise floor, etc, etc.

These may be limiting factors. So, beyond setting your amp up for max potential output, you have to carry these other determining factors.

But, the bottom line is this: how do your KNOW you're clipping your amp? Hearing it? Well, the amp sound theory went out the window. Back to square one.


----------



## Niebur3

bikinpunk said:


> Apples to apples.
> 
> Are you talking about clipping a 50w amp, or a 150w amp?
> Things that all determine gain are sensitivity, location, purpose, noise floor, etc, etc.
> 
> These may be limiting factors. So, beyond setting your amp up for max potential output, you have to carry these other determining factors.
> 
> But, the bottom line is this: how do your KNOW you're clipping your amp? Hearing it? Well, the amp sound theory went out the window. Back to square one.


How did the amp sound theory go out the window?


----------



## ashlar

Gain overlap IS clipping. When some add gain overlap to their amplifiers they are purposely causing their amplifiers to clip, for a reason. Nothing is wrong with clipping, some prefer more clipping than others. It is ONLY when it reaches the level of audibility that it can sound really bad. 

0 dB of gain overlap means absolutely no clipping, BUT your amplifier would not play very loudly compared to the following scenarios:

1.8 times the amplifier's actual sensitivity for full output will subjectively be 4.9 dB above a setting with 0 dB of gain overlap. The distortion is very minute and is less than 0.3% averaged for the duration of the music and is not audible.

3.16 times the amplifier's actual sensitivity for full output will subjectively be 9.4 dB above a setting with 0 dB of gain overlap. Even though the amplifier is clipping this is rarely audible to most listeners. Actually, this is the setting that Mark Eldridge uses in his gain setting procedure.(Peak distortion on most program material occurs for less than 3% of the program duration and is rarely audible to most listeners).

However, at 5.6 times the amplifier's sensitivity the subjective loudness is 13.3 dB above scenario 1 with no gain overlap. This can be heard by most listeners. Peak distortion on most program material occurs for about 15% of the program duration and is audible by most listeners.

It matters not which method you use, whether you want your amp to clip or not. Quite a lot of people prefer not to have their amps clip at all, but there are others that prefer to use the above tradeoffs to get volume.


----------



## ErinH

Niebur3 said:


> How did the amp sound theory go out the window?


aren't you guys saying that if you're talking about a clipped signal, then RC's challenge is no longer applicable?


----------



## t3sn4f2

Niebur3 said:


> Ok, lets say someone set there system up so that no clipping what so ever occurs (hopefully in a vehicle, they can still hear it because they would have to set so the most dramatic of passages in the music they are listening to, never clips - especially since this discussion has talked about the 2 and 1 ohm loads most people are using - which only drives it closer...again, not talking about major clipping, but the soft clipping that happens in extremely short waves), then you are saying that just because someone is unable to identify 24 or 24 (which Richard Clark requires to pass his test) there is absolutely without a doubt NO difference between amps (again keeping in mind he will NOT publish how you did, only that you failed even though some have passed the 1st round).
> 
> Do any of you realize that if you teachers in school required you to always get 100% right on every piece of homework and test to pass, you would still to this day be in grade school.
> 
> Are you also saying the all OpAmps sound the same since the are a part of the amp? That Burr-Brown is full of ****?
> 
> I am sure almost 100% of the seasoned people here can set their system so when they turn it up, it does not HARD clip. Many many even know that they could be SOFT clipping on a regular basis? We set up our systems not to hard clip using sign waves or other various methods....sign waves are NOT dynamics music.
> 
> *McIntosh and Tru may have extremely subtle differences, but you really think either Mac and Tru compared against Quantum would yield NO sound difference? Seriously*?


If the higher powered amp is attinuated to the level of the TRUE output of Quantum? No

Why is it so hard to accept that you aren't paying extra for quality within the clean actual wattage range. 

You are paying for name, reliability, warranty, service, longevity, art, features, amp protection, actual power, some freebie headroom, typically unneeded lower noise floor, wooden amp box to impress you friends, pride of ownership, on and on. What so damn shameful about that.

If I spend $200 on a pair of sneakers, I don't go around telling people that they are worth the money because they make me run faster. No, I say I payed more because they look nicer then a $20 dollar pair and no one has any problems with that.

What people are doing by being defiant in the face of scientific proof is they are misleading people out there that instead of spending there money on stuff that actually would help them have a more enjoyable music experience they then spend it on a jewel for there trunk and end up with a ****ty music experience.

I thought it was all about the music.


----------



## ashlar

bikinpunk said:


> aren't you guys saying that if you're talking about a clipped signal, then RC's challenge is no longer applicable?


True, as the program material would no longer be linear.


----------



## 89grand

ashlar said:


> Gain overlap IS clipping. When some add gain overlap to their amplifiers they are purposely causing their amplifiers to clip, for a reason. Nothing is wrong with clipping, some prefer more clipping than others. It is ONLY when it reaches the level of audibility that it can sound really bad.
> 
> 0 dB of gain overlap means absolutely no clipping, BUT your amplifier would not play very loudly compared to the following scenarios:
> 
> 1.8 times the amplifier's actual sensitivity for full output will subjectively be 4.9 dB above a setting with 0 dB of gain overlap.
> 
> 3.16 times the amplifier's actual sensitivity for full output will subjectively be 9.4 dB about a setting with 0 dB of gain overlap. Even though the amplifier is clipping this is rarely audible to most listeners. Actually, this is the setting that Mark Eldridge uses in his gain setting procedure.(Peak distortion on most program material occurs for less than 3% of the program duration and is rarely audible to most listeners).
> 
> However, at 5.6 times the amplifier's sensitivity the subjective loudness is 13.3 dB above scenario 1 with no gain overlap. This can be heard by most listeners. Peak distortion on most program material occurs for about 15% of the program duration and is audible by most listeners.
> 
> It matters not which method you use, whether you want your amp to clip or not. Quite a lot of people prefer not to have their amps clip at all, but there are others that prefer to use the above tradeoffs to get volume.


Good post!

I know I always setup my systems with the ability to clip the amps at some point. If not, I'd never know what my true maximum volume was.

I'll also say that I've probably drove my amps into some degree of clipping many many times. As long as it's not offensive to the ear, I don't really care. 

Maybe I just need bigger amps


----------



## ErinH

t3sn4f2 said:


> Why is it so hard to accept that you aren't paying extra for quality within the clean actual wattage range.
> 
> You are paying for name, reliability, warranty, service, longevity, art, features, amp protection, actual power, some freebie headroom, typically unneeded lower noise floor, wooden amp box to impress you friends, pride of ownership, on and on. What so damn shameful about that.



Agreed. There’s nothing wrong with paying a premium for these things. If I had the cash I’d be running Mcintosh amps in my house simply based on the name alone. Silly to some, but at least I’m honest with the reasoning, rather than saying that Mc sounds better than anything. *I can’t qualitatively say that as I’m not able to make the kind of comparisons to back that fully.* 


FWIW, I really don’t have a stance on how an amplifier sounds or how it doesn’t. I just think that when you start talking about clipping, then any idea of a fair comparison is thrown out the window. 

I set my system up with a Mark Eldridge-esque** method. Even after setting my gains optimally via this method, I still backed them down for purpose of level matching, noise floor, etc. That’s only with a 150w rated output per channel. Some run more than this. At one point last year I measured voltage on what I was actually giving my speakers with a 0db tone after going through all the setup with a scope and attenuated tones. On an amp rated for 150w I was only giving out 87w @ 4ohms (static load). Now, given that, what are the odds that I really threw my amp into clipping?
Furthermore, the impedance of my drivers never dip below rated nominal load (in most cases, 4 ohm). So, with that knowledge, and previous amp setup knowledge, I’m willing to bet that I still don’t hit clipping. At WOT I don’t have any issues with distortion caused by the amp. In fact, the problem is most cases is the media itself.
My point again is simple: in most cases of listening to music, clipping is not likely an issue. And if it is, and that's what you're hearing, then you've got other issues as stated. 

Why would you _want to or be okay with_ *listening* (not talking slight 2 second passages where something sounded odd) to music that you can audibly tell is caused from a clipped signal? This is why I get lost on why there is even discussion about clipped signal in this thread at all. 


**Headunit max unclipped volume with 0dB tone
Processor input/output measured and set with 0dB tone
Amplifier output set with -10db, or -5db tone, based off highest unclipped upstream signal.


----------



## ghostmechanic

Jesus this thread has gotten way off topic & probably confused the hell out of the OP. So I guess we should believe everything Mr. Clark says & take his word as the all mighty gospel... and then ditch any decent brand amps & sepakers we have so we can go out & replace them with whatever the cheapest POS is with the highest wattage claim we can find at Walmart or Best Buy


----------



## generalkorrd

ghostmechanic said:


> Jesus this thread has gotten way off topic & probably confused the hell out of the OP. So I guess we should believe everything Mr. Clark says & take his word as the all mighty gospel... and then ditch any decent brand amps & sepakers we have so we can go out & replace them with whatever the cheapest POS is with the highest wattage claim we can find at Walmart or Best Buy


Dont forget to throw a cheap eq on it, and you can make Roadmaster sound like Crown.


----------



## ashlar

ghostmechanic said:


> Jesus this thread has gotten way off topic & probably confused the hell out of the OP.
> 
> So I guess we should believe everything Mr. Clark says & take his word as the all mighty gospel... and then ditch any decent brand amps & sepakers we have so we can go out & replace them with whatever the cheapest POS is with the highest wattage claim we can find at Walmart or Best Buy


With respect to (1) above I totally agree with you.

With respect to (2), NO. If that is your understanding and takeaway, that is not what was being discussed. Simply put there are differences in amplifiers such as build quality, reliability, power output, channel configuration, looks, weight and some of you can add to the list.


----------



## t3sn4f2

ghostmechanic said:


> Jesus this thread has gotten way off topic & probably confused the hell out of the OP. So I guess we should believe everything Mr. Clark says & take his word as the all mighty gospel... and then ditch any decent brand amps & sepakers we have so we can go out & replace them with whatever *the cheapest POS is with the highest wattage claim* we can find at Walmart or Best Buy


Once again, the typical pushing to extremes to keep their point alive. I also like how you change the actual wattage to the wattage claim.


----------



## Mooble

bikinpunk said:


> How do you typically set your amps up?
> How do you evaluate the signal chain from start to finish?
> 
> 
> 
> 
> I realize that occasional clipping is likely to happen, but given how many times I’ve read threads, talked with people and benched my own gear, in addition to tweaking it after benching it from signal to final output, I can say with about 99% confidence that I rarely ever reach a clipped output on my setup. Just given the way I set the system up.
> The others who follow the method I use probably would say the same. If you’re clipping your amp enough for you to hear it, you need to look at an amp with more clean output or you’re going to have issues.
> I’m talking music here… not test tones or rap music trying to impress friends. I just don’t see people full out clipping their amps’ output while listening to music. Even WOT I don’t have any audible clipping for minutes at a time.


I know what you are saying. I could prevent my amp from clipping, but I would lose a lot of top end. I'm not talking about just one transient. I'm sure I clip transients all the time. If I stopped my amp from ALL clipping, I don't think I'd ever get enough volume. I can clip music and several seconds worth if I'm really rocking out. I need a more powerful amp, but that will come later. At least this amp allows me to clip without sounding completely awful. It's not a great solution, but one day I'll get another amp for my woofers.

If you truly cut out all clipping, I think most people would be running to buy more powerful amps. With soft clipping, you can be happy 90% of the time.


----------



## 89grand

ghostmechanic said:


> So I guess we should believe everything Mr. Clark says & take his word as the all mighty gospel... and then ditch any decent brand amps & sepakers we have so we can go out & replace them with whatever the cheapest POS is with the highest wattage claim we can find at Walmart or Best Buy


Not one single person in this thread has said anything even remotely similar to that.


----------



## Niebur3

bikinpunk said:


> Agreed. There’s nothing wrong with paying a premium for these things. If I had the cash I’d be running Mcintosh amps in my house simply based on the name alone. Silly to some, but at least I’m honest with the reasoning, rather than saying that Mc sounds better than anything. *I can’t qualitatively say that as I’m not able to make the kind of comparisons to back that fully.*
> 
> 
> FWIW, I really don’t have a stance on how an amplifier sounds or how it doesn’t. I just think that when you start talking about clipping, then any idea of a fair comparison is thrown out the window.
> 
> I set my system up with a Mark Eldridge-esque** method. Even after setting my gains optimally via this method, I still backed them down for purpose of level matching, noise floor, etc. That’s only with a 150w rated output per channel. Some run more than this. At one point last year I measured voltage on what I was actually giving my speakers with a 0db tone after going through all the setup with a scope and attenuated tones. On an amp rated for 150w I was only giving out 87w @ 4ohms (static load). Now, given that, what are the odds that I really threw my amp into clipping?
> Furthermore, the impedance of my drivers never dip below rated nominal load (in most cases, 4 ohm). So, with that knowledge, and previous amp setup knowledge, I’m willing to bet that I still don’t hit clipping. At WOT I don’t have any issues with distortion caused by the amp. In fact, the problem is most cases is the media itself.
> My point again is simple: in most cases of listening to music, clipping is not likely an issue. And if it is, and that's what you're hearing, then you've got other issues as stated.
> 
> Why would you _want to or be okay with_ *listening* (not talking slight 2 second passages where something sounded odd) to music that you can audibly tell is caused from a clipped signal? This is why I get lost on why there is even discussion about clipped signal in this thread at all.
> 
> 
> **Headunit max unclipped volume with 0dB tone
> Processor input/output measured and set with 0dB tone
> Amplifier output set with -10db, or -5db tone, based off highest unclipped upstream signal.


According to the article I posted the link to:

While this is undeniably true, *many of the amps used in a typical high end setup* will be found to be clipping during normal programme sessions. I'm not referring to gross overload - this is quite unmistakable and invariably sounds awful - regardless of the amplifier. Are we in car audio immune to this?

According to Wikipedia regarding clipping:

It is not simple to eliminate all clipping, as filtering (e.g. a high-pass filter) can align various frequencies in such a way as to create excessive peak outputs. The excessive peaks may become clipped even though the amplifier can play any single sine wave without clipping. Do you know without a doubt you are not even soft clipping when playing real music?

Effects of clipping even if you don't hear it according to Wikipedia:

When applied to a musical signal, the clipping may prevent a note from decaying in a normal amount of time. This can cause rapidly played notes to blend together.
Music which is clipped experiences amplitude compression, whereby all notes begin to sound equally loud because loud notes are being clipped to the same output level as softer notes.


----------



## ErinH

My overall point was missed. I'm not going to reiterate what I've said... this thread already has enough circles. 

I'm taking the exit. Stage left.

See you guys in another thread.


----------



## DaleCarter

Returning to the OP's question;

If you think that you can hear mild distortion or clipping in the bandpass of a sub amp (even though you can't), then buy the best A/B that you can afford. Be sure and use Tara Labs wire so that you maximize the benefit of your purchase.

If you want cool points or just have a boner for a particular amp, but an A/B.

If you live in reality, believe science and don't care about being "cool", buy the class D.


----------



## cubdenno

Although if I could spend 200 bucks and get a cheap amp and while playing it in the range I need it doesn't degrade the sound vs a 1000 dollar one of the same wattage, why wouldn't I? If I have to eq out a hump of boost and again have to spend a hundred on the eq I am still 700 bucks ahead. Sure my stereo wiener would be longer with the 1000 dollar amp but the girth of my wallet would be greater with the cheap amp. 

All this contends on the cheaper amp performing it's rated wattage.

there most definitely a price point in which something degrades early, SQ, lifespan, something. Where is that price point? That I am not sure of.


----------



## ghostmechanic

ashlar said:


> With respect to (1) above I totally agree with you.
> 
> With respect to (2), NO. If that is your understanding and takeaway, that is not what was being discussed. Simply put there are differences in amplifiers such as build quality, reliability, power output, channel configuration, looks, weight and some of you can add to the list.


Nope just read my user title. It says it all. If that's what you think my "understanding" is... I really don't care. I've repaired several hundred amplifiers over the years made by many brands & I've learned a lot from that. But what quite a few of you forgot is we're not supposed to be discussing anything other than subwoofer amps & which class is better for sound quality. 

Class D is generally more efficient so if you're limited on space &/or air circulation then it's probably what you should go with. As far as sound quality... it's obviously a subjectable subject.



t3sn4f2 said:


> Once again, the typical pushing to extremes to keep their point alive. I also like how you change the actual wattage to the wattage claim.


How am I trying to keep any point alive? 

What point am I trying to keep alive? Please tell me. This should be good.


----------



## 94VG30DE

ghostmechanic said:


> I've also rebuilt, designed, reconed, repaired & everything else with speakers for 25 years so I've also learned a great deal about those.


You started when you were 12? Holy crap. I feel like a slacker for starting at ~20 now. Gotta go find a time machine...


----------



## ghostmechanic

94VG30DE said:


> You started when you were 12? Holy crap. I feel like a slacker for starting at ~20 now. Gotta go find a time machine...


Yeah actually I did. I started tearing apart speakers & fixing them. I was fascinated with them. I still am. So yes you are a slacker

The first speaker project I ever did was a "blown" speaker in a mono Emerson portable radio/tape player. I fixed a lead wire that had broken. Man my soldering sucked back then. From there I started finding speakers in dumpsters & from friends & fixing those & adding them to that radio. I think I proved that little radio could push 8 speakers at .25ohm because I knew crap about series or parallel or impedences


----------



## MarkZ

Niebur3 said:


> And finally, people DID hear difference even with a non-clipped signal in Richard Clarks test, just couldn't name 24 out of 24...


I hadn't heard that. Do you have a link?


----------



## MarkZ

Niebur3 said:


> Are you also saying the all OpAmps sound the same since the are a part of the amp? That Burr-Brown is full of ****?


You seem to be convinced that just because somebody MARKETS a product, it actually does something that cheaper products don't do.

Do you have evidence that a Burr Brown op amp will sound different from a cheaper op amp? Which op amps, specifically, have you tried that you don't think sound good?

And does only the quality of the buffer matter? What about the op amps that control, say, the PWM supply (in some amps)? How about the op amps that serve as the differential input in the input stage? What would sound better to you: an amp with a BB op amp (which one?) or an amp with no input buffer at all, and purely discrete input and transconductance stages?

Again, I'm sorry to be so harsh, but I'm pointing out the fact that you DON'T KNOW ANYTHING ABOUT ELECTRONICS. You have no place in this discussion. Your entire argument throughout this thread has been "So-and-so sells a more expensive version of this item, so it MUST be better!" Please, learn about how these circuits work before spouting this crap.


----------



## MarkZ

ghostmechanic said:


> Nope just read my user title. It says it all. If that's what you think my "understanding" is...


When you sarcastically said that there was no point in buying quality amplifiers or speakers, you did one of two things:

1) Misunderstood the points that were being made. [Who said anything about all speakers sounding the same anyway??]

Or

2) Intentionally engaged in hyperbole and set up a strawman.

So, when the guy said you misunderstood, he was actually giving you the benefit of the doubt.


----------



## generalkorrd

> Again, I'm sorry to be so harsh, but I'm pointing out the fact that you DON'T KNOW ANYTHING ABOUT ELECTRONICS. You have no place in this discussion. Your entire argument throughout this thread has been "So-and-so sells a more expensive version of this item, so it MUST be better!" Please, learn about how these circuits work before spouting this crap


.

Just because somebody doesnt know a transistor from an capacitor, doesnt mean that he cant have an opinion, especially on something so subjective as this. You dont need to be an engineer to be able to hear the difference between 2 different amplifiers. I'm sure I dont need to tell you that for 90+% of people, if it's more expensive, it's better. With BB in particular, they are always hyped up in anything that they have been used. Do they deserve it? I dont know, as I have never owned any electronics with BB inside. I would assume they are doing something right though, besides marketing that is.


----------



## MarkZ

generalkorrd said:


> .
> 
> Just because somebody doesnt know a transistor from an capacitor, doesnt mean that he cant have an opinion, especially on something so subjective as this. You dont need to be an engineer to be able to hear the difference between 2 different amplifiers. I'm sure I dont need to tell you that for 90+% of people, if it's more expensive, it's better. With BB in particular, they are always hyped up in anything that they have been used. Do they deserve it? I dont know, as I have never owned any electronics with BB inside. I would assume they are doing something right though, besides marketing that is.


Sure, you can have an opinion on what sounds different, IF you've actually heard the two things you're talking about and have eliminated other factors that could have contributed to the difference.

This guy's been spewing all his "research", when in fact his "research" isn't really research, it's hearsay. He hasn't been able to support a single claim he's made with any data or any mechanistic explanation. 

* He said that "all music mastering companies use all class A amps", but didn't answer when I pressed him on the issue.
* He made claims that the temperature of a computer (in MY trunk) is not impacted by the temperature of the adjacent amplifier in a small confined space. 
* He made claims about class A/B amps drawing less current than class D.
* He doubted the efficiency numbers that somebody presented, without providing any of his own. 
* He made claims about people hearing clear differences between amplifiers in RC's challenge, and says so with certainty and authority, but doesn't seem to really know if that's true.
* He makes claims that BB op amps sound different from cheaper op amps (which ones?), although I'd wager he's never actually performed the test himself.

I've been a member of this forum for a long time, and it's rare for me to encounter a ******** artist as sloppy with his bullshitting as this guy.


----------



## dkh

Andy Wehmeyer said:


> This, in fact, is the right explanation of damping factor and is the same one that I've posted all over this form several times. Link in the earlier post is just half the story. At least it's half, though. Amplifier damping factor shouldn't be a factor in anyone's decision to buy an amp for subs. If you're driving a full-range loudspeaker at and above its resonance, it might be, but only as it helps to identify the amp's output impedance.


And of course, damping factor has nothing to do with how the amplifier controls the speaker (in plain English)?


----------



## generalkorrd

MarkZ said:


> Sure, you can have an opinion on what sounds different, IF you've actually heard the two things you're talking about and have eliminated other factors that could have contributed to the difference.
> 
> This guy's been spewing all his "research", when in fact his "research" isn't really research, it's hearsay. He hasn't been able to support a single claim he's made with any data or any mechanistic explanation.
> 
> * He said that "all music mastering companies use all class A amps", but didn't answer when I pressed him on the issue.
> * He made claims that the temperature of a computer (in MY trunk) is not impacted by the temperature of the adjacent amplifier in a small confined space.
> * He made claims about class A/B amps drawing less current than class D.
> * He doubted the efficiency numbers that somebody presented, without providing any of his own.
> * He made claims about people hearing clear differences between amplifiers in RC's challenge, and says so with certainty and authority, but doesn't seem to really know if that's true.
> * He makes claims that BB op amps sound different from cheaper op amps (which ones?), although I'd wager he's never actually performed the test himself.
> 
> I've been a member of this forum for a long time, and it's rare for me to encounter a ******** artist as sloppy with his bullshitting as this guy.


Ok, mastering companies/studios: who the hell knows, but probably not

computer: common knowledge that they dont like heat

Current: d draws less than a/b

Efficiency: see above, they go hand in hand

RC Challenge: I remember seeing something he posted about how some passed stage 1, but not stage 2, and it got all convoluted from there. I refer you to some of my earlier posts in this thread for my opinion on that.

BB: couldnt tell ya, never got a chance to a/b anything with BB in it. However, it would be easy to do, get a pair of zed amps, 1 with and 1 without the BB upgrade, lets do an a/b that way.

As far as bullshitting.. meh whatever, I just personally feel as he does, and many other people that the RC challenge is a ******** challenge, and that RC is not god.


----------



## t3sn4f2

ghostmechanic said:


> How am I trying to keep any point alive?
> 
> What point am I trying to keep alive? Please tell me. This should be good.





ghostmechanic said:


> Jesus this thread has gotten way off topic & probably confused the hell out of the OP. So I guess we should believe everything *Mr. Clark says & take his word as the all mighty gospel*... and then ditch any decent brand amps & sepakers we have so we can go out & replace them with whatever *the cheapest POS is with the highest wattage claim *we can find at Walmart or Best Buy


Because that's what he is saying right? 

Where does anyone but you say that this is what should be done. That's your extreme misrepresentation in order to try discredit. Either that or you simply just don't get the point of it all.


----------



## fastlane

*Sorry, I felt this thread needed a bit of humor in it. Oh wait, it already does. *


----------



## t3sn4f2

I forgot to mention, this IS the RC challenge done by him.




t3sn4f2 said:


> Page 2:
> 
> "Test 2 and 7----in this test the amps are driven *6db* into clipping. Since *6db* represents a *power level of 4:1* this means a *100 watt amp *would be attempting to produce a signal that would require a *400 watts amp *if the signal were to remain unclipped. *Even so it is rare that clipping at this level is audible*.


----------



## slomofo

what a mess of ****. i think both parties are grasping at straws at this point. grasping at tiny **** covered straws


----------



## generalkorrd

slomofo said:


> what a mess of ****. i think both parties are grasping at straws at this point. grasping at tiny **** covered straws


LOL **** covered straws


----------



## ghostmechanic

*Re: clas a/b or d amp for subwoofer sq?*



t3sn4f2 said:


> Because that's what he is saying right?
> 
> Where does anyone but you say that this is what should be done. That's your extreme misrepresentation in order to try discredit. Either that or you simply just don't get the point of it all.


No actually I came back to the thread after several hours & skimmed over the mess of posts & thought to myself how ridiculous the thread had gotten. I've started threads like this asking opinions & had people like yourself post novels from this research or that research from "experts" or where ever overwhelming me & just adding more confusion to what was a simple question. I was kind of putting myself in the OP's shoes. 
That & I have a twisted sense of humor. 

You don't know me so you have no idea what I was thinking or whether I "get the point" or not of those tests. And I've restrained from posting what my opinions are of Richard Clark or his tests because they're not relavent to the original question. That's why after re-reading one of my last posts I deleted what I typed about speakers. Hell I'd even forgotten that the OP was only asking about 2 specific model #s made by kicker.



slomofo said:


> what a mess of ****. i think both parties are grasping at straws at this point. grasping at tiny **** covered straws


Now that's friggin funny


----------



## 89grand

^^^At least you're helping clean up the mess by ignoring the side roads the original thread has taken and are now helping out the OP.


----------



## t3sn4f2

*Re: clas a/b or d amp for subwoofer sq?*



ghostmechanic said:


> No actually I came back to the thread after several hours & skimmed over the mess of posts & thought to myself how ridiculous the thread had gotten. I've started threads like this asking opinions & had people like yourself post novels from this research or that research from "experts" or where ever overwhelming me & just adding more confusion to what was a simple question. I was kind of putting myself in the OP's shoes.
> That & I have a twisted sense of humor.
> 
> You don't know me so you have no idea what I was thinking or whether I "get the point" or not of those tests. And I've restrained from posting what my opinions are of Richard Clark or his tests because they're not relavent to the original question. That's why after re-reading one of my last posts I deleted what I typed about speakers. Hell I'd even forgotten that the OP was only asking about 2 specific model #s made by kicker.


The question is not "simple" as you can see from the lengthy thread. "Get this amp, trust me " doesn't fly here. Or at least it didn't use to.


----------



## ghostmechanic

*Re: clas a/b or d amp for subwoofer sq?*



t3sn4f2 said:


> The question is not "simple" as you can see from the lengthy thread. "Get this amp, trust me " doesn't fly here. Or at least it didn't use to.


It is a simple question but people like you that keep posting what you think is relevant test results, opinions & whatever else that have made it such a lengthy thread. I failed to see anyone say "get this amp trust me" anywhere. I know I sure as hell didn't.

Since the original question has been forgotten I'm sure...


comfy_shoes said:


> ...I am curious to know wether the a/b zx400.2 bridged in mono or the zx400.1 class d will be a better choice. is there a percievable sound quality difference from anyones experience?


I can't even have an opinion as I have no experience with either amp. In fact my experiences with any Kicker amps goes back to one amp I owned in the mid '90s somewhere around the time they first introduced amplifiers.


----------



## MarkZ

*Re: clas a/b or d amp for subwoofer sq?*



ghostmechanic said:


> It is a simple question but people like you that keep posting what you think is relevant test results, opinions & whatever else that have made it such a lengthy thread. I failed to see anyone say "get this amp trust me" anywhere. I know I sure as hell didn't.
> 
> Since the original question has been forgotten I'm sure...
> 
> I can't even have an opinion as I have no experience with either amp. In fact my experiences with any Kicker amps goes back to one amp I owned in the mid '90s somewhere around the time they first introduced amplifiers.


Oh come off it. I know you're new here, but this forum is about discussions. It's not a help desk. The people who contribute here don't get paid. Really, if someone wants to know if one piece of equipment is "better" than another one, they're in the wrong forum. There are better places on the net to go to get those sorts of answers. 

That's actually been one of the major gripes that many of the earlier members keep bringing up, and they've actively tried to curtail those sorts of threads. Be my guest, you can try to change things so that all the threads are short, simple, and never allow discussion to exist if it's not in the original poster's interest... but expect that sort of thing to be met with a lot of resistance.


----------



## Niebur3

*Re: clas a/b or d amp for subwoofer sq?*

I started with my personal experience. I was then told my personal experience was not good enough because I am not an engineer and can't provide data to back it up. I then did research to get data to validate my point and have posted that research here. And now I am attacked, ridiculed and insulted for having a differing opinion. I have not insulted any of you and there is no place for that here.



MarkZ said:


> You seem to be convinced that just because somebody MARKETS a product, it actually does something that cheaper products don't do.
> 
> *No, I am a believer in certain brands but hve always been a skeptic regarding price higher = better. I have no "data" but I have owned Jl Audio, Rockford Fosgate, McIntosh, Tru, PPI, Jensen, Orion, Sony, Butler, Urban, JBL, Pioneer, Phoenix Gold and probably others I can't recall at the moment and I have "heard" the difference. I believe in higher brands because the SOUND better IMO.*
> 
> Do you have evidence that a Burr Brown op amp will sound different from a cheaper op amp? Which op amps, specifically, have you tried that you don't think sound good?
> 
> *Well, I currently have amps that I modified with Burr-Brown 2604 Op Amps, bought from Digikey - would you like the order number? I removed the JRC Op-Amps (can't remember the model number). I have had experience with some junk level JRC's and BB2134, which I like as well.*
> 
> And does only the quality of the buffer matter? What about the op amps that control, say, the PWM supply (in some amps)? How about the op amps that serve as the differential input in the input stage? What would sound better to you: an amp with a BB op amp (which one?) or an amp with no input buffer at all, and purely discrete input and transconductance stages?
> 
> *Well, Burr-Brown 2604's are my preference for most amps, however my newest Tru amp has NO PreAmp stage (which I paid for) in leu of the BB's*.
> 
> Again, I'm sorry to be so harsh, but I'm pointing out the fact that you DON'T KNOW ANYTHING ABOUT ELECTRONICS.
> 
> *I'm sorry to be so harsh, but you know nothing about me.*
> 
> You have no place in this discussion. Your entire argument throughout this thread has been "So-and-so sells a more expensive version of this item, so it MUST be better!" Please, learn about how these circuits work before spouting this crap.


*I have every right to be in this conversation. I have been in car audio and in competitions as a judge and competitor for 16 years. I started with my personal experience and when that was not good enough for you I found data online to support that I am not the only one and there is an explanation. Now that I have combatted what you state as the truth, you fell you need to attack me personally.*




MarkZ said:


> Sure, you can have an opinion on what sounds different, IF you've actually heard the two things you're talking about and have eliminated other factors that could have contributed to the difference.
> 
> This guy's been spewing all his "research", when in fact his "research" isn't really research, it's hearsay. He hasn't been able to support a single claim he's made with any data or any mechanistic explanation.
> 
> * He said that "all music mastering companies use all class A amps", but didn't answer when I pressed him on the issue.
> 
> *You may be right, however I have visited at least 5 and they all use class A amps...to clarify.*
> 
> * He made claims that the temperature of a computer (in MY trunk) is not impacted by the temperature of the adjacent amplifier in a small confined space.
> 
> *I only questioned you about that fact that a 20% less efficient amp would generate enough heat to cause the air temp in a trunk to rise so much that it would cause an issue to your computer. Where is your data? What is the temp inside the trunk using a Class A/B vs D? Have you even tried it?*
> 
> * He made claims about class A/B amps drawing less current than class D.
> 
> *Wow, that is out of context...are you a politician? I questioned the current draw of a Class D at 1 ohm vs a Class A/B at 4 ohm...are you really going to tell me that it would be that much different based on the current draw?*
> 
> * He doubted the efficiency numbers that somebody presented, without providing any of his own.
> 
> *Sorry, next time quote it and I can comment.*
> 
> * He made claims about people hearing clear differences between amplifiers in RC's challenge, and says so with certainty and authority, but doesn't seem to really know if that's true.
> 
> *This is from the link posted earlier in this thread regarding the Richard Clark Test - have you even bothered to open any links posted in this thread?*
> 
> *"Sometimes there are reports of people who believe they passed the test, but upon further examination it turns out that they only passed the preliminary round of 8 tests, where levels were not matched as closely as for the final test."
> 
> Do the results indicate I should buy the cheapest amp?
> 
> No. You should buy the best amplifier for your purpose. Some of the factors to consider are: reliability, build quality, cooling performance, flexibility, quality of mechanical connections, reputation of manufacturer, special features, size, weight, aesthetics, and cost. Buying the cheapest amplifier will likely get you an unreliable amplifier that is difficult to use and might not have the needed features. The only factor that this test indicates you can ignore is sound quality below clipping.
> 
> Richard Clark Amplifier Challenge FAQ*
> 
> I've been a member of this forum for a long time, and it's rare for me to encounter a ******** artist as sloppy with his bullshitting as this guy.


*It is amazing when you attack me for lack of facts and technical data and have yet to provide any of your own or even read information posted. You have made up your mind that the earth is flat....it is round my friend!*



MarkZ said:


> Oh come off it. I know you're new here, but this forum is about discussions. It's not a help desk. The people who contribute here don't get paid. Really, if someone wants to know if one piece of equipment is "better" than another one, they're in the wrong forum. There are better places on the net to go to get those sorts of answers.
> 
> That's actually been one of the major gripes that many of the earlier members keep bringing up, and they've actively tried to curtail those sorts of threads. Be my guest, you can try to change things so that all the threads are short, simple, and never allow discussion to exist if it's not in the original poster's interest... but expect that sort of thing to be met with a lot of resistance.


*I am confused here...is it okay to have a discussion as long as everyone agrees with you?*

*I didn't realize you were the all knowing God and authority on everything car audio. I don't necessarily expect you to change your mind, but no one should be attacked for having a different opinion. I hear differences between amps...you don't. There many people like me and many like you. I am NOT an engineer, but I have very good hearing....I don't know the technical reason why I hear the difference and am not willing to take engineering to find out the answer. I at least did research and found info backing up my side. Richard Clarks challenge has NO bearing if there is a difference or not and you guys using that excuse as proof is ignorant and irresponsible. Soft clipping will occur many times in even the best tunes systems when music is played (per the article I posted) and is almost IMPOSSIBLE to remove. This IS different than hard clipping that we hear. Richard Clark states that his test ONLY says that below the level of any clipping, there is NO audible difference between amps and even with that requires someone to score 24 of 24 to win the challenge.*


----------



## t3sn4f2




----------



## MarkZ

*Re: clas a/b or d amp for subwoofer sq?*



Niebur3 said:


> I started with my personal experience. I was then told my personal experience was not good enough because I am not an engineer and can't provide data to back it up. I then did research to get data to validate my point and have posted that research here. And now I am attacked, ridiculed and insulted for having a differing opinion. I have not insulted any of you and there is no place for that here.
> 
> 
> 
> *I have every right to be in this conversation. I have been in car audio and in competitions as a judge and competitor for 16 years. I started with my personal experience and when that was not good enough for you I found data online to support that I am not the only one and there is an explanation. Now that I have combatted what you state as the truth, you fell you need to attack me personally.*
> 
> 
> 
> 
> *It is amazing when you attack me for lack of facts and technical data and have yet to provide any of your own or even read information posted. You have made up your mind that the earth is flat....it is round my friend!*
> 
> 
> 
> *I am confused here...is it okay to have a discussion as long as everyone agrees with you?*
> 
> *I didn't realize you were the all knowing God and authority on everything car audio. I don't necessarily expect you to change your mind, but no one should be attacked for having a different opinion. I hear differences between amps...you don't. There many people like me and many like you. I am NOT an engineer, but I have very good hearing....I don't know the technical reason why I hear the difference and am not willing to take engineering to find out the answer. I at least did research and found info backing up my side. Richard Clarks challenge has NO bearing if there is a difference or not and you guys using that excuse as proof is ignorant and irresponsible. Soft clipping will occur many times in even the best tunes systems when music is played (per the article I posted) and is almost IMPOSSIBLE to remove. This IS different than hard clipping that we hear. Richard Clark states that his test ONLY says that below the level of any clipping, there is NO audible difference between amps and even with that requires someone to score 24 of 24 to win the challenge.*


I can't respond to your whole post because you haven't figured out how to post in this forum yet. Your comments seem to be embedded in mine. Work on that. It makes it very difficult for people to quote your posts, and the readability sucks.

Anyway, yes, you're free to speak! I don't own the site. Say what you want and I'll do the same. Just don't play the victim card when people call you out on your ********, lies, and misrepresentations. The latest example being your intentional misuse of RC's reports to support claims you made that were something else entirely. Think of it -- you're actually using RC's results to argue that people are hearing differences! Do you know how asinine that is?

Again, if I wanted to debate Clark, or your audio engineer friend, or some guy you heard about in Guam who wrote something on the internet, then let them come here and give their opinions. What you call "research" is hearsay. And you're not even doing a very good job of it. If you're not equipped to discuss certain subjects, say "I don't know enough about that to comment."

You're so entrenched in your position that you can't even acknowledge when someone makes a point contrary to yours. That tells me that you're disingenuous. You have no intention of listening to what anyone else has to say. Here are two examples. First, you asked why anybody even cares about efficiency. A couple people genuinely answered that question about why it's important to them. Rather than say, "Oh it's not important to me, but I guess it's important to you", you said one guy was lying about the efficiency numbers, and you doubted that my computer sharing a small airspace with my amp is affected by the temperature. Like WTF dude?? You haven't even seen my trunk! You haven't asked how small the airspace is! You haven't asked how close the amp is to the computer! You haven't asked what the computer's normal operating temp is and what its shutoff temp is! Instead, you just doubted the whole damned thing.

You also claim to know whether or not I consider dimming to be annoying. I told you I was at the threshold of dimming. You didn't even ask what that meant. You just made some snide comment.

The second example is when you tried to create the illusion that efficiency wasn't important because class D will draw more current when it's delivering more power to the speaker. You didn't say "Hmmm...if a class D and class B amp are delivering the same amount of power to a speaker (thereby creating the same output level), the class D amp will draw less current." No, you twisted things around by creating a scenario where a class D amp is delivering more power to a speaker, and tried to play it off as if it's a bad thing. Either you're really that stupid, which I don't think you are, or you're unable to admit that maybe your claims about efficiency being unimportant were really not well thought out.

Honestly, I have no use for your games. I've been an active member of this forum for several years now, and only twice did I encounter someone so bullheaded that I decided to put them on my block list. And the only reason I've done that is because I was certain that I'd never be interested in anything they ever had to say, because they showed that they were intellectually dishonest. Well, this will make three.


----------



## Brian10962001

KICK HIS A$$ SEABASS!


----------



## dkh

:surprised: I am reading this and thinking people can't discuss opinions anymore  which is why most people like me come one here  I thought this would have been a good debate between two people with very opposing views on a passionate subject.


----------



## cubdenno

Generally when two people are passionate about opposite views the level of the discussion escalates when there is not a mediator. 

The key to remember is that (from what I have read and even through what I am seeing here in this topic) there is not a quantifiable difference in a class a/b vs D amplifier driving a sub in sound quality. Like anything SQ it is ultimately a pure subjective experience. Which explains the differing opinions. 

Ultimately let your wallets first and ears second be the ultimate judge of what is best for your install. 

My opinion is: If you are not going to compete in a pure SQ manner, are going to do most of listening driving, then class D is not going to be detectable. The subtle nuances that some can hear that class a/b can reproduce better are probably going to be lost or even not missed.


----------



## sam3535

dkh said:


> :surprised: I am reading this and thinking people can't discuss opinions anymore  which is why most people like me come one here  I thought this would have been a good debate between two people with very opposing views on a passionate subject.


The issue is not about opinions or opposing opinions. Lately, there have been numerous threads and posts where opinion is represented as fact. Also, when known facts (i.e. provable quotations, etc.) have been modified to prove a point.

Tie this in with a boatload of new members here and very quickly erroneous information is spread as gospel.


----------



## fastlane

sam3535 said:


> Tie this in with a boatload of new members here and very quickly erroneous information is spread as gospel.


Last time I checked, ignorance wasn't predicated on join dates.  I've seen misinformation spread by new and old alike.


----------



## WLDock

89grand said:


> ...I've run PPI Art series amps which many people claim are one of the best amps ever made. Compared to other amps I've owned like JBL, I didn't see any difference in their behavior, whether loafing along or ran hard into clipping. They acted the same to me, even though many here would suggest the PPI's are much better than JBL, I didn't hear a difference between the two.


I have to say that many have made good points here but I have to agree that my observations are pretty similar. I thought I had pretty good ears but I know of many others that have even better ears and knowledge about audio than myself that use Class D amps....or brands like JBL. Many of these guys all ran many of the so called expensive SQ amps through the years and have tuned or judged more systems in a few years than I have in all the years I have been into car audio. 

One individual in particular I would put in the "Golden Ears" catagory actually believes in "Stereo Bass" if you can believe that. I have heard several of his past systems running Phoenix Gold MS-2125 & MS-2250 amps with the gold plated PCB's and well as systems with several XTANT amps however his current system is the best overall sounding to date. The current system used about 1000 watt for the front 3-way and about 2200 watts for each 15" sub. All of the amps are JBL's. SO, I guess the thinking here is that with this much power on tap the amps should never go into clipping. Now that is a different way of going about bass Sound Quality....load up on class D power so your amps won't clip.:bulb: What a concept! 

So, if you want solid and clean output is 500 watts of class A/B power better than 2200 watts of class D?

IMO with the right amp in the right system, class D, G, H, etc just makes sense. In a vehicle environment the better the efficiency the better the electrical system. The more power we can get to the speakers, the better the sound because clipping is the point where things don't sound so good. Because we are in an information age many of you young guys are smart and understand the electrical system and setup. However, back in the day I can't tell you how many times I would listen to someones car and the amps would clip because either they were setup wrong, had too little power, wrong wiring, etc....

A properly setup system can sound fine with the right class D amp for the job.


----------



## fastlane

Do any of you guys actually use your cars for transportation; or just an extension of your home listening area?  I think I have pretty good hearing, but unless I'm parked in my driveway, the differences between this amp and that amp, really all start to blend together. 

Don't get me wrong, I love my Arc. But at 70 down the highway (which is what I do with my vehicles, I drive them lol), I really can't say it's any better or worse than an amp at 1/2 it's cost. IMO.

Now my home theater room, that's a different story.


----------



## ChrisB

Depending on the age of the recording, Stereo Bass actually does exist. I have a vinyl conversion of Pink Floyd's Meddle and it is WAY more pronounced on the vinyl source than the Mobile Fidelity Sound Labs version of the same recording!

Of course, the stereo bass thing starts to become moot in a vehicle because it is hard to localize those frequencies below 80 Hz.


----------



## chad

I have a room at work I spec'd stereo subs.

1 reason......

Acoustic summing is different then electrical summing


----------



## sam3535

fastlane said:


> Last time I checked, ignorance wasn't predicated on join dates.


I didn't say that it was; apparently reading comprehension isn't your forte. Take another look at my post. *Tie this in with a boatload of new members*....erroneous information combined with new members equals the new members repeating what they have been told (bad information). More so when the newer members refuse to utilize the search function.


----------



## fastlane

sam3535 said:


> I didn't say that it was; apparently reading comprehension isn't your forte.


And communication isn't yours.


----------



## sam3535

fastlane said:


> And communication isn't yours.


Not sure how to respond to that one; I don't speak your language apparently.

Back to the topic at hand!


----------



## fastlane

sam3535 said:


> Not sure how to respond to that one; I don't speak your language apparently.


Yup, it seems English is tough for you.  I'm just screwing with ya in response to your little quip earlier. 



> Back to the topic at hand!


What topic would that be? This thread derailed quite some time ago.


----------



## sam3535

fastlane said:


> Yup, it seems English is tough for you.  I'm just screwing with ya in response to your little quip earlier.
> 
> 
> 
> What topic would that be? This thread derailed quite some time ago.


It is my third language, so I do sometimes struggle with it! I read the derailment, but its fun to keep this at the top.


----------



## niko084

89grand said:


> A: No one could ever pick out which amplifier was playing on a subwoofer in any test. B: Damping factor in real world use means next to nothing. C: Use the most efficient amplifer you have...(hint, class D)


Eh, I would LOVE to see that "unbiased" test and be apart of it.
Also depends on the equipment we are working with.

I can tell you for certain myself I very well could easily hear a difference when moving from a Kicker Kx400.2 to a Kx400.1 on my old Mb Quart 10's, so could about everyone else that was into high end audio that got into my car.

If you are really into SQ, you probably wouldn't be running a Kicker amp.
That being said I would probably agree with going with a class D amp.

But I am willing to bet most people with good subs in a well tuned system could hear the difference between the two.


----------



## 89grand

niko084 said:


> Eh, I would LOVE to see that "unbiased" test and be apart of it.
> Also depends on the equipment we are working with.
> 
> I can tell you for certain myself I very well could easily hear a difference when moving from a Kicker Kx400.2 to a Kx400.1 on my old Mb Quart 10's, so could about everyone else that was into high end audio that got into my car.
> 
> If you are really into SQ, you probably wouldn't be running a Kicker amp.
> That being said I would probably agree with going with a class D amp.
> 
> But I am willing to bet most people with good subs in a well tuned system could hear the difference between the two.


Maybe it was louder, but that's the only reason you could tell.

I don't believe anyone can tell a difference in a blind test between most amps playing at the same level on subwoofers. No one has ever been able to pass a test that I'm aware of, and I'm not just talking about Richard Clarks test.

What other amps can you tell apart? Can you tell a Crossfire from an Infinity amp? How about a JBL from a Rockford Fosgate? How about a Kicker from a Orion?


----------



## t3sn4f2

89grand said:


> Maybe it was louder, but that's the only reason you could tell.
> 
> I don't believe anyone can tell a difference in a blind test between most amps playing at the same level on subwoofers. No one has ever been able to pass a test that I'm aware of, and I'm not just talking about Richard Clarks test.
> 
> What other amps can you tell apart? Can you tell a Crossfire from an Infinity amp? How about a JBL from a Rockford Fosgate? How about a Kicker from a Orion?


It's hard to stay away right!


----------



## 89grand

t3sn4f2 said:


> It's hard to stay away right!


I've tried, but I just can't do it.:laugh:


----------



## DaleCarter

If a person can tell the difference between two competent amps on subwoofers, surely they could hear the differences in speaker cable. If so, become an instant millionaire

James Randi Offers $1 Million If Audiophiles Can Prove $7250 Speaker Cables Are Better - JREF - Gizmodo


----------



## niko084

89grand said:


> Maybe it was louder, but that's the only reason you could tell.
> 
> I don't believe anyone can tell a difference in a blind test between most amps playing at the same level on subwoofers. No one has ever been able to pass a test that I'm aware of, and I'm not just talking about Richard Clarks test.
> 
> What other amps can you tell apart? Can you tell a Crossfire from an Infinity amp? How about a JBL from a Rockford Fosgate? How about a Kicker from a Orion?


I also did a switch on some old Audiobahn stuff from Class A/B to D.

I also noticed a difference from a Phoenix Gold Xenon 200.2 to a Xenon 600.1, although to make that one fair it was in two different cars, but of similar size and both dampened, same headunit, extremely similar settings.

I wont refute that it is far less noticeable especially with a sub simply do to the raw nature that they output massive levels of distortion anyways.

I'm certain it would be easy to tell going from an expensive A/B to a cheap D or even a cheap A/B to an expensive D you would probably hear a big difference, the good amp being better sounding, which is why I'm only trying to state amps from the same company and lineup.


----------



## niko084

DaleCarter said:


> If a person can tell the difference between two competent amps on subwoofers, surely they could hear the differences in speaker cable. If so, become an instant millionaire
> 
> James Randi Offers $1 Million If Audiophiles Can Prove $7250 Speaker Cables Are Better - JREF - Gizmodo


Aw, yes the laughing stock of all tests.

Now to the contrary, did you read about how someone wanted to take that test and Randi turned him down do to wanting things like a socially dead room, chosen high end speakers, and reference equipment?

Sounds like he didn't want to lose his money... James Randi is the next biggest laughing stock standing next to Al Gore and his "I created the internet" claims.

I won't say myself I think there is a difference there, nor would I say even if there was it's worth it, but somebody did, they wrote up some modifications to the test and Randi said No, that doesn't look good.

Lastly amps have a WAY bigger impact on sound than speaker cable.

Take any two amps, something really expensive and something really walmart.
Then put it on a set of really good speakers, then use some magnet wire solid core *22awg* and crank it up, then swap it out for some really good 12awg and listen again, to expand it use 100ft runs of cable. Then switch the amp out and do the same, the cheap amp on the good large cable still wont sound as good as the good amp on the cheap small cable, but you will notice a difference between the 22awg at 100ft run vs the 12awg at a 100ft run, although it will be fairly small.

*Yes cable SIZE and Capacitance makes a different* The fact it says Monster on it means jack.


----------



## 89grand

Can you expand on this?

What would the cheap amp sound like and what would the expensive amp sound like? I mean an amplifier is just there to amplify the original signal, it shouldn't add or subtract anything. I'm assuming the expensive amp just amplifies and the cheap amp adds something to the signal?


----------



## MarkZ

89grand said:


> Maybe it was louder, but that's the only reason you could tell.
> 
> I don't believe anyone can tell a difference in a blind test between most amps playing at the same level on subwoofers. No one has ever been able to pass a test that I'm aware of, and I'm not just talking about Richard Clarks test.
> 
> What other amps can you tell apart? Can you tell a Crossfire from an Infinity amp? How about a JBL from a Rockford Fosgate? How about a Kicker from a Orion?


FWIW, there _have_ been some reports of people passing other tests with reasonable amps (*) ... but by the skin of their teeth. Like, teetering at the edge of statistical significance.

(*) By "reasonable", I'm not referring to the difference between certain esoteric home audio designs. You know, the designs that spit all over the "straight wire with gain" concept.

But I don't know what this means because the test methodology is all over the place, and so we have to be careful about what conclusions we draw. Can we extrapolate the findings in the home audio realm to car audio? Home audio and pro audio have some unique animals that they call amplifiers. If we find that these things are imparting certain audible artifacts in comparison to a "run of the mill" amp, does that blow everything up and mean that we have to start paying attention to the "Kicker vs. MTX -- which one should I buy?" threads?

This is where measurements (you know, with test equipment) are a pretty useful tool. There's been so much focus in this thread on double blind listening tests and such, ... But nobody's talking about the actual electrical performance. Yeah, the subjectivists argue that differences in sound can't be revealed by electrical measurements, but hopefully we're all smarter than that here. 

So when we take one amp and amplify its signal, and we talk another amp and amplify its signal, and then run it through a DIFFERENCE circuit, and it gives you an almost ruler-flat line ... is that enough evidence for some of you guys to conclude that there won't be a difference in sound between those amps? And the key question is: Just how flat does "ruler-flat" have to be? We DO know certain things about human hearing to be able to make certain predictions about these sorts of issues...


----------



## MarkZ

niko084 said:


> Aw, yes the laughing stock of all tests.
> 
> Now to the contrary, did you read about how someone wanted to take that test and Randi turned him down do to wanting things like a socially dead room, chosen high end speakers, and reference equipment?
> 
> Sounds like he didn't want to lose his money... James Randi is the next biggest laughing stock standing next to Al Gore and his "I created the internet" claims.
> 
> I won't say myself I think there is a difference there, nor would I say even if there was it's worth it, but somebody did, they wrote up some modifications to the test and Randi said No, that doesn't look good.


This is why these guys really need to take the money out of scientific inquiry. The choice of test parameters should be based on logic rather than likelihoods of losing money, you know? There's too much bias going into these debates.



> Lastly amps have a WAY bigger impact on sound than speaker cable.
> 
> Take any two amps, something really expensive and something really walmart.
> Then put it on a set of really good speakers, then use some magnet wire solid core *22awg* and crank it up, then swap it out for some really good 12awg and listen again, to expand it use 100ft runs of cable. Then switch the amp out and do the same, the cheap amp on the good large cable still wont sound as good as the good amp on the cheap small cable, but you will notice a difference between the 22awg at 100ft run vs the 12awg at a 100ft run, although it will be fairly small.
> 
> *Yes cable SIZE and Capacitance makes a different* The fact it says Monster on it means jack.


Speaker cable capacitance? Should only be on the order of a few picofarads per meter.


----------



## npdang

ashlar said:


> On a slightly different take, here is what Mark Eldridge had to say on the subject.
> 
> *Ahhh... The amp challenge is resurfacing yet again. Another generation of car audio fanatics to enlighten!
> 
> Seriously guys and gals, no one has ever (that's EVER!!!) proven that they can hear the difference between amplifiers under the criteria in which the test is administered. I've been through it many times, and even thought I heard a significant difference once. That was until I took it again and proved myself wrong.
> 
> The test parameters are totally on the up and up, and there is no hidden capability to slant the results. Every part of the test set up is plainly visible. Last time I saw it, even the circuit boards were visible. The entire test is designed to determine if there are audible differences between two amplifier designs under normal, undistorted listening conditions.
> 
> How many people have taken it now, Richard? Several thousand?
> 
> Come on everybody. Somebody needs to take RCs money! He's been winning this challenge for way too long now.
> 
> C-ya!
> --------------------
> Mark Eldridge*


The challenge was never about proving that all amps sound the same. If you read it carefully, one of the very fundamental premises of the challenge is that amps DO sound different... it's whether or not those differences can be controlled to such a degree that they cannot be distinguished by the human ear. So far I've yet to see/hear of any compelling reason or evidence why they cannot.


----------



## Brian10962001

Ok, this is kind of annoying to me at this point, all of these "tests" assume some kind of fixed and controlled laboratory setting, your car is FAR FROM THIS. I routinely overdrive my amps and I don't set my gains and volume with an o scope so seriously the tests have no *real* bearing in this discussion. For that matter cars are generally a noise polluted environment so that takes even more out of ones ability to tell which is which. Now for the biggest thing that's got me curious, if you're comparing amp a to amp b of different manufacturer's wouldn't the crossover circuit have a big impact on the sound of the amp, almost as much so as any other factor? One of the biggest advantages of my Lanzar amp was the phase shift, this made a big difference in my old Grand Prix so why hasn't any of this been discussed? My biggest issue with the class D amps I've owned were reliability, and all of them were manufactured in the early part of the 2000s. For what it's worth, I don't think anyone in a moving vehicle could tell you what type of amplifier you're running. There are just to many factors to consider before you ever worry about what class your amp is. I would go with the best deal you can find on the biggest and best brand you can afford (up to a point you won't see me with BRAX or TRU unless I get a steal on them).


----------



## ChrisB

Brian10962001 said:


> Now for the biggest thing that's got me curious, if you're comparing amp a to amp b of different manufacturer's wouldn't the crossover circuit have a big impact on the sound of the amp, almost as much so as any other factor?


Crossovers are a moot point with many here since a good bit of the DIY crowd uses the active crossover in their head units. 

But you do have a point, built-in crossovers on amplifiers vary GREATLY from one amp manufacturer to another. IMHO, the built-in crossover on my Crossfire BMF1000d is the absolute WORST when it comes to blocking the higher frequencies from reaching the subwoofer. I found that the amplifier sounded MUCH better with the mere addition of a Coustic XM6 because it wasn't letting frequencies above 100 Hz get reproduced by the subwoofer. 



Brian10962001 said:


> One of the biggest advantages of my Lanzar amp was the phase shift, this made a big difference in my old Grand Prix so why hasn't any of this been discussed?


My HU handles this too. In swapping subwoofer amplifiers out in my Mustang, I had to run my Clarion DPX1851 out of phase from the rest of my system. Prior to that, most of the other amps were fine with the subwoofer in phase.


----------



## niko084

MarkZ;909012Speaker cable capacitance? Should only be on the order of a few picofarads per meter.[/QUOTE said:


> Probably, I'm uncertain of it, but a lot of people are moderately concerned with it when they have longer runs.
> 
> Anyways, my point wasn't to state if anything was "worth it" or not, nor trying to totally debunk any viewpoints or arguments.
> 
> Anyways, as for the amps, probably a difference in dynamic headroom, could have been stereo vs mono *don't remember how it was hooked up*, could have been partially 1ohm-2ohm-4ohm in the various setups, could have been the difference in S/N, THD, a million variables in there.
> 
> I wouldn't say the base architecture of the amp has a lot to do with it myself, being class AB vs class D.


----------



## quality_sound

MarkZ said:


> I think it does serve to reinforce the fact that any potential differences between amplifiers are so small that we can't even pick out the difference between $1000 amps and $100 amps 100% of the time.


So if we can't _always_ hear a difference then we can _never_ hear a difference? That seems to be what RC is trying to say with his test. Obviously if you got 23 of 24 tries correct you didn't guess right so you have to have heard something to distinguish them the first 23 times. Also, if the differences, below clipping and level matched, were so inaudible as to be indistinguishable then why does he need to eq anything in the first place?


----------



## MarkZ

quality_sound said:


> So if we can't _always_ hear a difference then we can _never_ hear a difference? That seems to be what RC is trying to say with his test. Obviously if you got 23 of 24 tries correct you didn't guess right so you have to have heard something to distinguish them the first 23 times. Also, if the differences, below clipping and level matched, were so inaudible as to be indistinguishable then why does he need to eq anything in the first place?


No argument from me. If you got 23 out of 24 correct, then you probably heard real differences. Has this happened though? Just because he has a limit in his test doesn't mean that subjects are bumping up against that limit. That's the crap thing about the test -- it doesn't seem like the results are readily available to the public. But maybe I'm wrong about that.

Anyway, see npdang's post re: EQing. RC acknowledges that there are differences between amps. If he didn't, he wouldn't be setting up rules like EQing, or noise stuff, etc. The conclusions we should be drawing from the test are not that amps sound the same, but rather that amps can be made to sound the same with some modifications.


----------



## Niebur3

06BLMUSTANGGT said:


> Crossovers are a moot point with many here since a good bit of the DIY crowd uses the active crossover in their head units.
> 
> I might be wrong on this, if I am I deeply apologize for my ignorance, but doesn't the pre-amp crossover/eq section of the amp still come into play even if you do not use it? Doesn't the signal still flow through the pre-amp circuitry which can introduce some coloration? Do all pre-amp sections have op-amps that depending on their quality can effect the overall sound of the amp? Again, if wrong I apologize for any confusion.


----------



## Niebur3

MarkZ said:


> No argument from me. If you got 23 out of 24 correct, then you probably heard real differences. Has this happened though? Just because he has a limit in his test doesn't mean that subjects are bumping up against that limit. That's the crap thing about the test -- it doesn't seem like the results are readily available to the public. But maybe I'm wrong about that.
> 
> You are correct, he does not make any of the results public. I don't see why he won't, I mean, maybe no one has ever come that close, maybe people have...but is really sucks that we can find out that info and make a more educated assumption about the actual data. All he has published is that some people have passed the 1st round (12 of 12) but then failed the next round when the levels were adjusted even closer.
> 
> Anyway, see npdang's post re: EQing. RC acknowledges that there are differences between amps. If he didn't, he wouldn't be setting up rules like EQing, or noise stuff, etc. The conclusions we should be drawing from the test are not that amps sound the same, but rather that amps can be made to sound the same with some modifications.


Keep in mind RC also stated that the test only is set to prove you can ignore a sound quality difference between amplifiers below clipping (according to his test rule sheet), once everything you mentioned is adjusted accordingly.


----------



## chad

You are gonna hear differences in the tolerances of the support passive components tied to the op-amp LONG before you will hear the differences between the op-amps.

You have top put an op-amp test into a pretty ****ty situation before you are gonna hear much noticeable difference.

I have personally put op-maps in said ****ty conditions.


----------



## Niebur3

chad said:


> You are gonna hear differences in the tolerances of the support passive components tied to the op-amp LONG before you will hear the differences between the op-amps.
> 
> You have top put an op-amp test into a pretty ****ty situation before you are gonna hear much noticeable difference.
> 
> I have personally put op-maps in said ****ty conditions.


So, ignoring the op-amp, could the pre-amp section of the amp still add coloration even if you have everything turned off? If you have 2 identical amps one with a high quality pre-amp section and one with a horrible quality pre-amp section, if you are NOT using that pre-amp for anything other than the pots, can the signal just flowing through cause coloration?


----------



## niko084

Niebur3;909477If you are NOT using that pre-amp for anything other than the pots said:


> "Technically" Yes, if a signal has to pass through something it will change in some way. Realistically I can't say I have tested it but I doubt it would be noticeable.


----------



## DaleCarter

niko084 said:


> Aw, yes the laughing stock of all tests.
> 
> Now to the contrary, did you read about how someone wanted to take that test and Randi turned him down do to wanting things like a socially dead room, chosen high end speakers, and reference equipment?
> 
> Sounds like he didn't want to lose his money... James Randi is the next biggest laughing stock standing next to Al Gore and his "I created the internet" claims.


First, the Randi challenge requires the challenger to provide their own reference system and their own source material, as long as all are commercially available. This is to prevent any bitching by the challenger about below spec gear.

If you are referring to Michael Freemer, he wanted to use his own Tara Labs cables and Randi said no. Randi said they could test Pear first and, if Fremer was successful, they could then test Tara Labs. After all, the challenge is made TO Pear Labs.

Then Pear Labs backed out on their promise to provide the cables.


How about this suggestion;

Take the test and you have a 66% chance of making Randi look bad. 

Result 1 - you hear the difference and bank $ 1M, Randi is proven to be the laughing stock you claim him to be, Pear forever quashes any challenge to their product

Result 2 - you accept the challenge and Randi backs out, Randi is proven to be the laughing stock you claim him to be, Pear forever quashes any challenge to their product

Result 3 - you can't tell the difference.



Either way, esoteric speaker wire is useless in a car. Pick speaker wire based on size, flexibiloity and durability, not electron alignment, skin effect or other hocus pocus.


----------



## MarkZ

niko084 said:


> "Technically" Yes, if a signal has to pass through something it will change in some way. Realistically I can't say I have tested it but I doubt it would be noticeable.


Some amps have defeatable controls, some don't. It's basically just a switch instead of a knob.

I use the example of a kicker amp that I used to use as a bench amp. It had a nice smooth 1dB hump at 40Hz even with the "sub boost" knob turned all the way down. So, obviously it wasn't bypassing the circuit. That kinda sucked, but if I cared it would have been easy to EQ out -- just match the f and the q. Might be some group delay issues, but probably not.

Better way would be to take a jumper wire and solder it in so that it bypassed the circuit altogether. The problem comes when the crossover circuit doubles as the buffer or even as the differential in the input stage. Then you have to bypass the caps instead but leave the op amp in place.

BTW, I assume these are the sorts of modifications that RC uses. Does anybody really object to bypassing input frills when testing amplifier performance? I mean, just because it shares the same physical case as an amplifer doesn't make it part of the amplifier, know what I mean?

Also, I agree with chad about the passive elements. The capacitor and resistor tolerance are going to determine your filter properties. And for people who are REALLY anal, the resistors in the op amp circuit will determine the gain structure. There are usually two resistors on the front end whose ratio determines the level of the input signal (ie. gain of the input), and two other resistors in the negative feedback loop that determine the gain of the actual amplifier. If you want to level match your left and right channels, make sure these ratios are equal on both sides. Still won't be perfect after that, but you'll get damned close.


----------



## niko084

DaleCarter said:


> After all, the challenge is made TO Pear Labs.
> 
> How about this suggestion;
> 
> Take the test and you have a 66% chance of making Randi look bad.
> 
> Result 1 - you hear the difference and bank $ 1M, Randi is proven to be the laughing stock you claim him to be, Pear forever quashes any challenge to their product
> 
> Result 2 - you accept the challenge and Randi backs out, Randi is proven to be the laughing stock you claim him to be, Pear forever quashes any challenge to their product
> 
> Result 3 - you can't tell the difference.


Well how about these few than... Everyone uses his "test" to say that there is no difference in "speaker wires" *NOT* "Pear cables cannot give a defined change in sound over Monster"

People need to start considering what the test REALLY states.

Secondly, if you take a look on his website he pulled that out, he is no longer offering that... Why? I couldn't tell you, nor do I care.

Lastly, since when does some jack with no education instantly have a phd in neuroscience? 

Want science, put up Pear's cables against the Monsters on a scope and see which one comes out more accurate to the original wave.

So far there is no testing equipment available to rear nerve reactions from the ear to convert it into a wave, so you cannot without a doubt tell which cable gives a more accurate reproduction, it would also have to be done numerous times to weed out any chance of a fluke test result.

Now before we are done here, he rules out what he refers to as "paranormal".
So what is he asking to hear, he isn't asking for guesses at which cable is "better" or which is which... He is asking for you to define what is different, what kinda definition is he looking for, I'm guessing spatial or bright wont quite cut it, so what does he want? Does he want me to tell him that a kick drum hit was missing at 3:02 of Track 11?

I'm not saying everyone "can" hear the difference between any speaker wire, let alone specifically Pear and Monster, or weather or not even if they can if it's worth it. I'm stating the fact that Randi's tests are seriously off the wall and for the most part if not completely unbeatable.

The government has psychics on it's payroll and for that ability.
What does that tell you?

I'm not saying either way, but I'm not a fan of jack #$# skeptics who have no education or experience in the topics they are being skeptical about. I am skeptical myself, but I make it a point to become very educated before I come to any of my own conclusions and I certainly don't push them as far as he has.

Maybe next he will start putting up competitions to prove or disprove global warming... Good lord, this would be another one that would never end, at least not in his lifetime.


----------



## MarkZ

niko084 said:


> So far there is no testing equipment available to rear nerve reactions from the ear to convert it into a wave, so you cannot without a doubt tell which cable gives a more accurate reproduction, it would also have to be done numerous times to weed out any chance of a fluke test result.


No, but we know a great deal about jnd's through psychophysical testing. So, it's not too difficult to measure the differences in the electrical or even the acoustical domain, and then make predictions about whether or not they'd be audible. If, for example, the differences turn out to be several orders of magnitude lower than human thresholds, then it's pretty safe to conclude that there would be no perceptual difference.

In fact, some of this amp crap can be evaluated in the same way.


----------



## niko084

MarkZ said:


> No, but we know a great deal about jnd's through psychophysical testing. So, it's not too difficult to measure the differences in the electrical or even the acoustical domain, and then make predictions about whether or not they'd be audible. If, for example, the differences turn out to be several orders of magnitude lower than human thresholds, then it's pretty safe to conclude that there would be no perceptual difference.
> 
> In fact, some of this amp crap can be evaluated in the same way.


That's a good point, something I didn't even know.
But you would still have to test a VERY large group in order to get a decent number, and you could still have distant results.

My opinion on the Class A/B vs Class D btw: wasn't to say the Class D is a worse amp do to it being Class D, but with quite a few different companies the Class D specs compared to the same lineup of Class A/B amps are massively different at a raw component selection standpoint.


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## lycan

makes me all warm 'n fuzzy to know that some debates will never end 

please refresh my memory ... what _exactly_ is it about gain, power, frequency response, noise & distortion that _fails_ to completely describe the voltage (and subsequent current) delivered to a pair of speaker terminals?


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## niko084

lycan said:


> please refresh my memory ... what _exactly_ is it about gain, power, frequency response, noise & distortion that _fails_ to completely describe the voltage (and subsequent current) delivered to a pair of speaker terminals?


You live in Austin... That's good, go to school there, UAT is one of the best engineering schools in the country..

You will learn exactly what the difference is.


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## lycan

niko084 said:


> You live in Austin... That's good, go to school there, UAT is one of the best engineering schools in the country..
> 
> You will learn exactly what the difference is.


no need ... i've already got a master's degree in engineering from MIT 

Plus, i already know exactly what the difference is


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## ChrisB

Everyone tends to put way too much focus on subwoofers which are responsible for 5 to 15% of most "musical" content. IMHO, subwoofers are the most effective wasters of power in the audio chain. Exactly how much of that power reaching the subwoofer terminals gets converted to heat versus energy again?


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## niko084

lycan said:


> no need ... i've already got a master's degree in engineering from MIT
> 
> Plus, i already know exactly what the difference is


I would say "pics or ban" but I'm not a mod here. :laugh:


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## thehatedguy

You know those little things called multibit DACs? Well the fellow you are talking to was on the design team that invented those. Being VP of Research at Crystal Semiconductor was another job title he has held before starting his own company in Austin.



niko084 said:


> I would say "pics or ban" but I'm not a mod here. :laugh:


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## niko084

thehatedguy said:


> You know those little things called multibit DACs? Well the fellow you are talking to was on the design team that invented those. Being VP of Research at Crystal Semiconductor was another job title he has held before starting his own company in Austin.


Well maybe I took what he was saying incorrectly then?

I should also note being someone else is here backing you up and your posts look like you are quite educated in the field, I want to apologize for the response I gave, but I am sure you can understand how the average child plays off a incredible fake amount of knowledge... Unfortunately quite common in various forums.


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## T3mpest

niko084 said:


> Well how about these few than... Everyone uses his "test" to say that there is no difference in "speaker wires" *NOT* "Pear cables cannot give a defined change in sound over Monster"
> 
> People need to start considering what the test REALLY states.
> 
> Secondly, if you take a look on his website he pulled that out, he is no longer offering that... Why? I couldn't tell you, nor do I care.
> 
> Lastly, since when does some jack with no education instantly have a phd in neuroscience?
> 
> Want science, put up Pear's cables against the Monsters on a scope and see which one comes out more accurate to the original wave.
> 
> So far there is no testing equipment available to rear nerve reactions from the ear to convert it into a wave, so you cannot without a doubt tell which cable gives a more accurate reproduction, it would also have to be done numerous times to weed out any chance of a fluke test result.
> 
> Now before we are done here, he rules out what he refers to as "paranormal".
> So what is he asking to hear, he isn't asking for guesses at which cable is "better" or which is which... He is asking for you to define what is different, what kinda definition is he looking for, I'm guessing spatial or bright wont quite cut it, so what does he want? Does he want me to tell him that a kick drum hit was missing at 3:02 of Track 11?
> 
> I'm not saying everyone "can" hear the difference between any speaker wire, let alone specifically Pear and Monster, or weather or not even if they can if it's worth it. I'm stating the fact that Randi's tests are seriously off the wall and for the most part if not completely unbeatable.
> 
> The government has psychics on it's payroll and for that ability.
> What does that tell you?
> 
> I'm not saying either way, but I'm not a fan of jack #$# skeptics who have no education or experience in the topics they are being skeptical about. I am skeptical myself, but I make it a point to become very educated before I come to any of my own conclusions and I certainly don't push them as far as he has.
> 
> Maybe next he will start putting up competitions to prove or disprove global warming... Good lord, this would be another one that would never end, at least not in his lifetime.


There are even bigger rewards out there from multiple sources for any proof of psychic powers if you can show it in a lab setting. Simply claim your power and demonstrate it under controlled conditions, nobody has ever done that either, what do that tell you.


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## t3sn4f2

lycan said:


> makes me all warm 'n fuzzy to know that some debates will never end
> 
> please refresh my memory ... what _exactly_ is it about gain, power, frequency response, noise & distortion that _fails_ to completely describe the voltage (and subsequent current) delivered to a pair of speaker terminals?


Fortunatly for some, nothing.  

For others though, there's that very real and unwavering voodoo stage between the speaker cone and the conscious mind.


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## lycan

niko084 said:


> Well maybe I took what he was saying incorrectly then?
> 
> I should also note being someone else is here backing you up and your posts look like you are quite educated in the field, I want to apologize for the response I gave, but I am sure you can understand how the average child plays off a incredible fake amount of knowledge... Unfortunately quite common in various forums.


no apology necessary  i'm flying utr these days.

So I won't be participating in these types of debates anymore (much to the glee of many, i suspect!). Of course amplifiers sound different! One only needs to turn the gain knob all the way _down_ on one, and all the way _up_ on the other to demonstrate this simple conclusion. BUT ... one needs to also understand the logical extensions of this simple argument 

The inescapable conclusion is that amps sound different ONLY because of a rather small subset of well-known parameters : power, gain, frequency response, noise & distortion. Once any differences in these parameters are "nullified", network theory (quite well developed, to say the least) ... as well as any well-controlled listening tests ... tells us that no sonic differences remain.

But wait ... what about the type of solder used? Simple ... if it doesn't materially impact power, gain, frequency response, noise & distortion, then it won't impact the way the amp "sounds". Same goes for what type of opamps, what type of wire, even in what CLASS the amplifier operates.


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## niko084

lycan said:


> The inescapable conclusion is that amps sound different ONLY because of a rather small subset of well-known parameters : power, gain, frequency response, noise & distortion. Once any differences in these parameters are "nullified", network theory (quite well developed, to say the least) ... as well as any well-controlled listening tests ... tells us that no sonic differences remain.


Ok, I think what you are saying is power, gain, freq response and noise and distortion are actual effecting numbers, and that the class itself has absolutely nothing to do with it?


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## lycan

niko084 said:


> Ok, I think what you are saying is power, gain, freq response and noise and distortion are actual effecting numbers, and that the class itself has absolutely nothing to do with it?


Yes.

Take two power amps, one is Class AB and the other is Class D. If the differences between the amps in power, gain, frequency response, noise & distortion (both amps operating into the same load, over the same intended frequency range) are below the well-established limits of human hearing, then the amps will be sonically indistinguishable.

They have no "choice" but to sound the same. A speaker can only react to the voltage at it's terminals (the current will be determined by the speaker's impedance, by ohm's law, and therefore the current will be the same if the voltages are the same). If the two amps in question present the same voltage to the speaker's terminals, how can the speaker possibly know anything else about the amplifiers?


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## thehatedguy

And crossover distortion...


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## thehatedguy

At what point does a class D sample enough to look and perform (efficiency wise) like a class a/b? To me it would seem like the more samples you get, the closer you are going to get to a/b in terms of sonics and efficiency. And at or near that point, wouldn't the benefits of a class d topology wash out?


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## MarkZ

thehatedguy said:


> At what point does a class D sample enough to look and perform (efficiency wise) like a class a/b? To me it would seem like the more samples you get, the closer you are going to get to a/b in terms of sonics and efficiency. And at or near that point, wouldn't the benefits of a class d topology wash out?


It asymptotically approaches "perfect" with higher sampling. And, with higher sampling rate, you can push potential filter artifacts further away from 20kHz. Technically, you should actually begin to approach class A performance because there aren't Vbe issues.


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## kkant

niko084 said:


> I'm not saying either way, but I'm not a fan of jack #$# skeptics who have no education or experience in the topics they are being skeptical about. I am skeptical myself, but I make it a point to become very educated before I come to any of my own conclusions and I certainly don't push them as far as he has.


Consider the claim that Darth Vader was a real person who lived a long time ago in a distant galaxy. Would you say I need to be highly educated in the lore of Star Wars before I can justifiably dismiss this claim? There are some claims which require an enormous amount of evidence/proof before they are worthy of even a minimal amount of consideration.


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## MiniVanMan

niko084 said:


> but I am sure you can understand how the average child plays off a incredible fake amount of knowledge... Unfortunately quite common in various forums.


You need to be careful, because at 25 you're barely out of school, and not an abundance of real world engineering experience. There are quite a few here that are.


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## thehatedguy

I was thinking it would be more towards A than a/b. But you would have to have some serious processing to control the switcher once you got that many samples. Right? I'm not up to date on the SOTA class D stuff. It is very exciting to think about something like that happening though.



MarkZ said:


> It asymptotically approaches "perfect" with higher sampling. And, with higher sampling rate, you can push potential filter artifacts further away from 20kHz. Technically, you should actually begin to approach class A performance because there aren't Vbe issues.


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