# Misconceptions in car audio



## ChrisB (Jul 3, 2008)

As discussed in another thread, I would like to know what some of the common misconceptions are in car audio. I'll start with my biggest pet peeve...

Damping factor on an amplifier DOES NOT equate to better cone control, tighter bass, or better sound quality (Ess que) contrary to what many have heard. Also, the higher the number doesn't always necessarily mean the "better" an amplifier is, especially in the 12 volt world. Damping factor in the car audio world was a spec contrived by someone's marketing department and continued on through the decades with the bigger number meaning the better the amp.

I am trying to find the clinical trials that blew this myth, and I am having a hard time locating it. Regardless, if the damping factor is greater than 50, chances are one will NEVER hear the difference.

ETA: I forgot the biggest boo boo. In the past, some of the amplifiers with the highest damping factors used to cheat. They rated them at the circuit board instead of the speaker leads or terminals just so they could post a bigger number. 

I have more misconceptions, but I want the collective to chime in on things such as slew rate, stiffening capacitors, THD, etc.


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## Chaos (Oct 27, 2005)

Can't recall where I heard that, but it seems to me that where amplifier dampening factors are concerned anything over 50 is supposed to be adequate and higher slew rates are favorable. 

I choose an amp based on power output, physical size and cost. Beyond that, I rely on reviews of real world experience to judge performance potential until I can hear it for myself. The rest of the specs have come to mean virtually nothing to me over the years.


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## WRX/Z28 (Feb 21, 2008)

My favorite. 15" subs are sloppy. 8" are tight.


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## chad (Jun 30, 2005)

Sealed enclosures for SQ.


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## chad (Jun 30, 2005)

http://www.diymobileaudio.com/forum/diy-mobile-audio-sq-forum/50596-top-car-audio-myths.html


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## 89grand (Nov 23, 2006)

You can't run your power wire next to your RCA's or speaker wire.


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## ChrisB (Jul 3, 2008)

chad said:


> http://www.diymobileaudio.com/forum/diy-mobile-audio-sq-forum/50596-top-car-audio-myths.html


Thank you. I knew such a thread existed, but, I kept searching for the keyword misconception. My search fu is weak today.


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## Chaos (Oct 27, 2005)

benefits of Big 3 wiring upgrade


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## chad (Jun 30, 2005)

ChrisB said:


> My search fu is weak today.


Search Fu is not what you need, you need mojo.


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## ChrisB (Jul 3, 2008)

Chaos said:


> benefits of Big 3 wiring upgrade


Especially on a stock battery and alternator.


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## WRX/Z28 (Feb 21, 2008)

Chaos said:


> benefits of Big 3 wiring upgrade





ChrisB said:


> Especially on a stock battery and alternator.


ahhh... but which stock alternator, and what is the guage wiring used in said vehicle for ground and hot?


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## ChrisB (Jul 3, 2008)

WRX/Z28 said:


> ahhh... but which stock alternator, and what is the guage wiring used in said vehicle for ground and hot?


Civics like most of the ricers drive with their 60 to 90 amp alternators. 

It is going to take a lot more than the Big 3 to help them out!


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## WRX/Z28 (Feb 21, 2008)

Brand X amplifier is underrated by 50% or more!


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## Lanson (Jan 9, 2007)

Zed has a lot to say about these topics:
Zed Audio Corporation

But what he says might surprise you.


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## WRX/Z28 (Feb 21, 2008)

--Car audio shops are filled with talentless morons that provide no real service to anyone. 

--If you bought an expensive brand name audio product, you absolutely overpaid, and therefore you must be a idiot. 

--The only good car audio brands are those that fly under the radar...


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## kyheng (Jan 31, 2007)

A $1000 wire/cable sounds better than $1 wire/cable.


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## remeolb (Nov 6, 2009)

Sub bass in a car is localize-able over 80 Hz.

I read that here and it seems to make sense to me...

http://www.diymobileaudio.com/forum/diy-mobile-audio-sq-forum/70071-lacking-bass-up-front.html


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## ChrisB (Jul 3, 2008)

WRX/Z28 said:


> Brand X amplifier is underrated by 50% or more!


How about a certain brand that advertises 50x4 OR 325x2 all on 25 amps of fusing. 200 watts RMS I can almost believe with that fuse level but there is NO WAY I believe 650 watts RMS on 25 amps of fusing.

If you can find one of those amps, they still go for $700 to $750 which I find even more shocking...


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## remeolb (Nov 6, 2009)

Is it possible for us to make this thread one with a stated myth and then proof to back it up? That way it's possible to weed out the people who think something.


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## Lanson (Jan 9, 2007)

remeolb said:


> Is it possible for us to make this thread one with a stated myth and then proof to back it up? That way it's possible to weed out the people who think something.



Like a snopes for car audio?


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## remeolb (Nov 6, 2009)

fourthmeal said:


> Like a snopes for car audio?


Yeah I guess that is what I meant. I think if it was kept accurate and free of opinions it would be pretty useful.


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## Niebur3 (Jul 11, 2008)

"Putting subs in front of the car will ensure the bass is coming from the front"

I don't know if this is a myth or what, but last year at finals, I sat in several cars with subs in the dash, center console or even kick panels and in a couple of those (cars and people will remain nameless) me and several others noticed the bass seemed to be coming from the rear or hard to locate. I believe you need to properly blend and eq no matter where they are physically located. I heard others where the subs were in the trunk and seemed as they were out on the hood!


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## Chaos (Oct 27, 2005)

Flat RTA = SQ nirvana


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## Oliver (Jun 25, 2007)

... anything i believe ...


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## Lanson (Jan 9, 2007)

Big subs are "slower" , small subs are "tighter".

And...

That people don't realize that power is 10 base logarithmic to SPL.


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## MiniVanMan (Jun 28, 2005)

Power rating is important.

Lower impedance means more output

Damping factor means something but Slew Rate is ignored.

Vibrations dampers used as noise blockers.

Higher order crossovers are better.

Car audio speakers are more durable than home, or "gasp" pro audio.

RMS power

Off-axis response is related to anything other than cone diameter.

And finally,

Tymphany, or Tang Band drivers are now worth much more because a car audio company put their name on it.


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## Oliver (Jun 25, 2007)

MiniVanMan said:


> Off-axis response is related to anything other than cone diameter.


what about domes = shape of driver and the lil pecker thingy on some spaekers  ?


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## MiniVanMan (Jun 28, 2005)

a$$hole said:


> what about domes = shape of driver and the lil pecker thingy on some spaekers  ?


Off-axis response is related to anything other than *cone* diameter.


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## eggyhustles (Sep 18, 2008)

15's for the lows
8's for tight bass


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## IBcivic (Jan 6, 2009)

99% of TSPENCED's postings


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## Oliver (Jun 25, 2007)

MiniVanMan said:


> Off-axis response is related to anything other than *cone* diameter.


just funning joo


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## MiniVanMan (Jun 28, 2005)

a$$hole said:


> just funning joo


I know, but it was a good point to make.


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## ChrisB (Jul 3, 2008)

Chaos said:


> Flat RTA = SQ nirvana


Eww, gross... Flat sounds... well... FLAT!



remeolb said:


> Is it possible for us to make this thread one with a stated myth and then proof to back it up? That way it's possible to weed out the people who think something.



Well, to back up my assertion about the amplifier that I mentioned, one can NOT violate Ohm's Law. Volts X Amps X Efficiency = Watts.

To give the benefit of the doubt, let's assume a full 14.4 volts with 70% efficiency, even though we know this isn't the case. Best case is generally 13.8 volts under load whereas worst case is 12.5 volts if one drives a vehicle with an Electrical Load Detector!

14.4 X 25 X 70% = 252 watts (ETA: which is why I can buy the 200 watts RMS claim)

Now to get 650 watts RMS with said efficiency, one would need about 65 amps of fusing! 



amitaF said:


> 99% of TSPENCED's postings


lol, Infinity Reference components are THE BEST! (this is a misconception and purely a beauty is in the eye of the beholder thing)


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## Lexus1 (Feb 18, 2010)

An amplifier's damping factor depends on the amount of filtering in the power supply, but much more importantly, the amount of feedback and how it's configured in the circuit. And yeah, it's not so important as other specs. 
My favorite deliberate misconception based on completely shockingly moronic ignorance:
Back in the early 90s I was reading a car audio trade magazine; a contributor stated the best way to wire an amp is to hook it up to the biggest possible positive cable, the bigger the better, and to hook up the smallest possible ground lead, as small as possible, like 28 guage, because that would force more power to the speakers instead of uselessly going to the chassis. His command of grammar was well in keeping with the text of his article as well.
I don't think he was taken too seriously, but imagine somebody on the consumer level not knowing any better taking that and rolling with it!


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## chad (Jun 30, 2005)

Lexus1 said:


> An amplifier's damping factor depends on the amount of filtering in the power supply,


Wow, a misconception in a misconception thread.


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## Lexus1 (Feb 18, 2010)

chad said:


> Wow, a misconception in a misconception thread.


And if that were an unreinforced statement, you'd be right, but one must take into context the rest of what I wrote.
The damping factor of an amp IS affected by filtering to a degree, as I wrote. If the filter cap's current reserves collapse due to a big current spike, that will most definitely have an effect on the damping factor! Frequency control starts to go. But in car audio, that is not so much a concern since most amps in the last twenty years or so at least have good amounts of filtering onboard, and most good installs I'm sure have added capacitance via large value (1fd +) stiffener caps to reinforce the amp's power supplies.


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## remeolb (Nov 6, 2009)

MiniVanMan said:


> Power rating is important.
> 
> Lower impedance means more output
> 
> ...


Let's keep with the "SNOPES" thing. I'd love to read why these are myths. Even just links would be great. I really think a thread with all of this info in one area would be awesome. As many myths as I've finally grasped I know there has to be more.


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## Lexus1 (Feb 18, 2010)

Or to describe it another way: one could have a 1kw / chan amp with zero feedback but have 10fds of filtering available to the power supply. It would have a very low damping factor regardless! Or one could have a 1kw / chan amp with a well designed feedback network, both global and local, but only have say 1,000uf of filtering available to the power supply. THAT amp would have an exponentially higher damping factor. There's still a correlation either way; the former would have needless amounts of filtering based on the circuit, and the latter not nearly enough. BUT the latter design would work better in the real world.


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## Dryseals (Sep 7, 2008)

Lexus1 said:


> Or to describe it another way: one could have a 1kw / chan amp with zero feedback but have 10fds of filtering available to the power supply. It would have a very low damping factor regardless! Or one could have a 1kw / chan amp with a well designed feedback network, both global and local, but only have say 1,000uf of filtering available to the power supply. THAT amp would have an exponentially higher damping factor. There's still a correlation either way; the former would have needless amounts of filtering based on the circuit, and the latter not nearly enough. BUT the latter design would work better in the real world.


I'm not so sure I would agree with you on any of this, not that I could be wrong, but I have never seen were the filter properties of a power supply had any affect on the "dampening factor" of an amplifier.

The term dampening factor popped up in the later sixties as a "selling" prop. It was the solid state guys way of trying to prove their equipment was better than the tubes folks. I can remember reading hundreds of specs where they showed it. Over all result, it didn't amount to much unless you took it to extremes. But it sure did look good on a brochure. As for power supply filtering, unless you have a grave amout of ripple floating around, chances are you'll never know it's there. As for one who's hung a million scopes on power supplies, some can be very ugly. Turn that volt/div knob to the left and it looks pretty clean.


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## ChrisB (Jul 3, 2008)

Here is a good read regarding damping factor: http://www.monstercable.com/mpc/stable/tech/A2412_Damping_Factor_Article.pdf

Crown explains it too, but I worry that they are more about marketing with the "bigger is better aspect" than the true meaning: http://www.crownaudio.com/pdf/amps/damping_factor.pdf

ETA: Here is another link to the hype: http://www.caraudioforum.com/vbb2/showthread.php?t=110359&highlight=Myth

As well as here: http://www.gen5alive.com/forums/showthread.php?t=9259


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## MiniVanMan (Jun 28, 2005)

remeolb said:


> Let's keep with the "SNOPES" thing. I'd love to read why these are myths. Even just links would be great. I really think a thread with all of this info in one area would be awesome. As many myths as I've finally grasped I know there has to be more.


I'd love to, and no offense, but I'm not wasting my time anymore.

First off, I can provide links, data, and a wealth of information only to have this thread disappear like all the other really informative threads in less than a month. It'll end up buried amongst all the "what subwoofer should I get", and people won't bother reading it anyway.

If you're curious, you can search DIYMA for a lot of the previous fights we've had over this stuff, or you can Google it. I'm not trying to be a dick, but I've spent countless hours putting together really informative posts, and they just get buried and the same bull **** that we've tried to debunk gets perpetuated.


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## MiniVanMan (Jun 28, 2005)

ChrisB said:


> Here is a good read regarding damping factor: http://www.monstercable.com/mpc/stable/tech/A2412_Damping_Factor_Article.pdf
> 
> Crown explains it too, but I worry that they are more about marketing with the "bigger is better aspect" than the true meaning: http://www.crownaudio.com/pdf/amps/damping_factor.pdf


I still find it funny that "damping factor" is what's described as "controlling as speaker". Nobody talks about "slew rate". I wonder why? 

I mean, which would really control cone movement?

Slew rate - Wikipedia, the free encyclopedia

Damping factor - Wikipedia, the free encyclopedia


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## WRX/Z28 (Feb 21, 2008)

MiniVanMan said:


> I still find it funny that "damping factor" is what's described as "controlling as speaker". Nobody talks about "slew rate". I wonder why?
> 
> I mean, which would really control cone movement?
> 
> ...


The explanation of damping factor from the wikipedia article:

_*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.

Speaker diaphragms have mass, and their surrounds have stiffness. Together, these form a resonant system, and the mechanical cone resonance may be excited by electrical signals (e.g., pulses) at audio frequencies. But a driver with a voice coil is also a current generator, since it has a coil attached to the cone and suspension, and that coil is immersed in a magnetic field. For every motion the coil makes, it will generate a current that will be seen by any electrically attached equipment, such as an amplifier. In fact, the amp's output circuitry will be the main electrical load on the "voice coil current generator". If that load has low resistance, the current will be larger and the voice coil will be more strongly forced to decelerate. A high damping factor (which requires low output impedance at the amplifier output) very rapidly damps unwanted cone movements induced by the mechanical resonance of the speaker, acting as the equivalent of a "brake" on the voice coil motion (just as a short circuit across the terminals of a rotary electrical generator will make it very hard to turn). It is generally (though not universally) thought that tighter control of voice coil motion is desirable, as it is believed to contribute to better-quality sound.

A high damping factor indicates that an amplifier will have greater control over the movement of the speaker cone, particularly in the bass region near the resonant frequency of the driver's mechanical resonance. However, the damping factor at any particular frequency will vary, since driver voice coils are complex impedances whose values vary with frequency. In addition, the electrical characteristics of every voice coil will change with temperature; high power levels will increase coil temperature, and thus resistance. And finally, passive crossovers (made of relatively large inductors, capacitors, and resistors) are between the amplifier and speaker drivers and also affect the damping factor, again in a way that varies with frequency.

For audio power amplifiers, this source impedance Zsource (also: output impedance) is generally smaller than 0.1 ohm (Ω), and from the point of view of the driver voice coil, is a near short-circuit.*_

 Is this saying anything other than the common belief that damping factor = control over cone movement? or am I misreading this?


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## chad (Jun 30, 2005)

Lexus1 said:


> And if that were an unreinforced statement, you'd be right, but one must take into context the rest of what I wrote.
> The damping factor of an amp IS affected by filtering to a degree, as I wrote. If the filter cap's current reserves collapse due to a big current spike, that will most definitely have an effect on the damping factor! Frequency control starts to go. But in car audio, that is not so much a concern since most amps in the last twenty years or so at least have good amounts of filtering onboard, and most good installs I'm sure have added capacitance via large value (1fd +) stiffener caps to reinforce the amp's power supplies.



If you are running an amplifier to the point of collapse of the filtering, AKA clipping and beyond, then damping factor is the least of your worries, you are running it out of it's design spec.. Lets concentrate on amplifiers working in a linear fashion.


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## chad (Jun 30, 2005)

Lexus1 said:


> Or to describe it another way: one could have a 1kw / chan amp with zero feedback but have 10fds of filtering available to the power supply. It would have a very low damping factor regardless! Or one could have a 1kw / chan amp with a well designed feedback network, both global and local, but only have say 1,000uf of filtering available to the power supply. THAT amp would have an exponentially higher damping factor. There's still a correlation either way; the former would have needless amounts of filtering based on the circuit, and the latter not nearly enough. BUT the latter design would work better in the real world.


I can't think of ONE modern SS car amp that does not have copious amounts of feedback... 

You know you can have an amp with VERY LITTLE filtering, VERY LITTLE, it has nothing to do with farads so lets not get into a debate on caps in rails.. because the filtering is largely dependent on how often it's getting hit with a charge. Many modern amplifiers outside car audio have little filtering, some basically a Pi Network behind a fast PWM power supply, it's not uncommon at all. They also have staggering damping factors.


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## Lexus1 (Feb 18, 2010)

chad said:


> ......a Pi Network behind a fast PWM power supply, it's not uncommon at all. They also have staggering damping factors.



That's it, exactly. I was trying to keep it a nutshell as much as I could, but ultimately there are so many other factors, like how fast the switching supply is, it's operating impedance, what the amp overall is "seeing" from the driven load..... and as Dryseals pointed out, it became an advertising point. A cheap way for one technology to be described as superior to another without really saying anything.
What really bugs me and it's audio-industry wide, but seems to be more prevalent in car audio on a retail level, is sales people saying "That speaker puts out 250 watts!" Well, they don't of course..... it's the amp's job to put out wattage, and the speaker's job in part is to be able to handle a certain amount of power!


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## Lanson (Jan 9, 2007)

MiniVanMan said:


> I'd love to, and no offense, but I'm not wasting my time anymore.
> 
> First off, I can provide links, data, and a wealth of information only to have this thread disappear like all the other really informative threads in less than a month. It'll end up buried amongst all the "what subwoofer should I get", and people won't bother reading it anyway.
> 
> If you're curious, you can search DIYMA for a lot of the previous fights we've had over this stuff, or you can Google it. I'm not trying to be a dick, but I've spent countless hours putting together really informative posts, and they just get buried and the same bull **** that we've tried to debunk gets perpetuated.



Sticky request, especially if we can get it in a solid format.


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## Dryseals (Sep 7, 2008)

fourthmeal said:


> Sticky request, especially if we can get it in a solid format.


I'd go for it, but the first and foremost question I would ask is how much power do you really need?

It's a common question and I see folks spending a lot of cash on huge amps only to turn the gain down so they can match things.


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## Pillow (Nov 14, 2009)

You can kill a subwoofer if you run too little power to it! 

Sealed boxes are for SQ. Ported is for the SPL kids. You cannot make a ported box sound good. 

That amp worked when I removed it from my brothers-uncles-mothers car.

My brand X sound deadener is way better than your brand Y.


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## MiniVanMan (Jun 28, 2005)

WRX/Z28 said:


> The explanation of damping factor from the wikipedia article:
> 
> _*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.
> 
> ...


http://www.diymobileaudio.com/forum/diyma-tutorials/15011-damping-factor-what-worthless.html


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## rc10mike (Mar 27, 2008)

That all amps sound the same in real life situations.


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## MiniVanMan (Jun 28, 2005)

tvrift said:


> That all amps sound the same in real life situations.


Ahhhh, for **** sake, there's always one.

I bet that chrome on your IDMax's makes 'em sound better too.


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## freemind (Sep 11, 2008)

MiniVanMan said:


> Ahhhh, for **** sake, there's always one.
> 
> I bet that chrome on your IDMax's makes 'em sound better too.





Oh **** yeah!

The chrome drastically reduces Temporal reflections :laugh:


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## freemind (Sep 11, 2008)

That Car Toys have the best custom Pre-fab boxes and the lowest prices!


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## remeolb (Nov 6, 2009)

fourthmeal said:


> Sticky request, especially if we can get it in a solid format.


Yes! That's what I'm talking about.


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## remeolb (Nov 6, 2009)

MiniVanMan said:


> I'd love to, and no offense, but I'm not wasting my time anymore.
> 
> First off, I can provide links, data, and a wealth of information only to have this thread disappear like all the other really informative threads in less than a month. It'll end up buried amongst all the "what subwoofer should I get", and people won't bother reading it anyway.
> 
> If you're curious, you can search DIYMA for a lot of the previous fights we've had over this stuff, or you can Google it. I'm not trying to be a dick, but I've spent countless hours putting together really informative posts, and they just get buried and the same bull **** that we've tried to debunk gets perpetuated.


I totally get what you're saying. I know it would be some work but if we could get a thread like this with good info and evidence to back it up "stickied" I think it would be incredibly beneficial to the forum.


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## sam3535 (Jan 21, 2007)

remeolb said:


> I totally get what you're saying. I know it would be some work but if we could get a thread like this with good info and evidence to back it up "stickied" I think it would be incredibly beneficial to the forum.


As MVM said; search the forum, it's all there. Why start yet another thread rehashing what has already been discussed?


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## remeolb (Nov 6, 2009)

I'm suggesting that there should be one well organized thread with the majority of common misconceptions explained and debunked. I know that all of the info is scattered about the forum. I just think that it's a big enough topic to be better organized.


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## chad (Jun 30, 2005)

oh yeah, it's all there, gives you a taste of what a good 3 week bicker can be about without resorting to name calling.


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## chad (Jun 30, 2005)

remeolb said:


> I'm suggesting that there should be one well organized thread with the majority of common misconceptions explained and debunked. I know that all of the info is scattered about the forum. I just think that it's a big enough topic to be better organized.


well, get crackin


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## Stel (Mar 11, 2008)

WRX/Z28 said:


> The explanation of damping factor from the wikipedia article:
> 
> Is this saying anything other than the common belief that damping factor = control over cone movement? or am I misreading this?


He doesn't mention any numbers. He could be talking about very low damping factors ...the reference for the wikipedia article is from 1966...a popular time for tube amps. Also he never says that the 'better' control would be audible. Anyone can edit wikipedia btw.


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## rc10mike (Mar 27, 2008)

MiniVanMan said:


> Ahhhh, for **** sake, there's always one.
> 
> I bet that chrome on your IDMax's makes 'em sound better too.


From what Ive been told, the chrome actually enhances the rigidity of the basket.


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## chad (Jun 30, 2005)

tvrift said:


> From what Ive been told, the chrome actually enhances the rigidity of the basket.


so does cold air :surprised:


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## Pillow (Nov 14, 2009)

> Quote:
> Originally Posted by remeolb View Post
> I'm suggesting that there should be one well organized thread with the majority of common misconceptions explained and debunked. I know that all of the info is scattered about the forum. I just think that it's a big enough topic to be better organized.





> well, get crackin


x2 Thanks for stepping up and taking charge of the issue. I like to see people take initiative on these opportunities.


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## benny (Apr 7, 2008)

"Subwoofers should not be crossed higher than 50Hz."

:laugh:


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## chad (Jun 30, 2005)

well played


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## Lars Ulriched (Oct 31, 2009)

How about Old School amp better than new amps? Old Soundstream is better than new soundstreams? Old school alpine HU better than new alpine HU? Any idea? Im tired of ppl bombarding me with their old school stuffs....


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## ChrisB (Jul 3, 2008)

benny said:


> "Subwoofers should not be crossed higher than 50Hz."
> 
> :laugh:


What if one is running JL Audio subs in JL Audio's recommended sealed enclosure? You know, those subs that model with a +3dB 55 Hz peak then drop like the DOW indicator below 50 Hz.


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## ChrisB (Jul 3, 2008)

Lars Ulriched said:


> How about Old School amp better than new amps? Old Soundstream is better than new soundstreams? Old school alpine HU better than new alpine HU? Any idea? Im tired of ppl bombarding me with their old school stuffs....


You know, around this time in 2007, I thought old school was better due to having issues with a Memphis Power Reference amp. I've since learned that i was wrong.:blush:


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## [email protected] (Jun 12, 2008)

Is there really valid data that show damping factor doesnt contribute to much. I guess by valid data I mean a rig set up with lasers and stuff to read the cone movement accurately? I am not stating it does or doesnt, but without some high dollar test setup I dont think anybody can claim it does either way


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## WRX/Z28 (Feb 21, 2008)

Old school is still better... even if it's just for the "cool factor"


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## ChrisB (Jul 3, 2008)

WRX/Z28 said:


> Old school is still better... even if it's just for the "cool factor"


Yeah, if it is a 60s muscle car.


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## DaveRulz (Jun 22, 2006)

> well, get crackin


X3

If you want a thread containing all sorts of information that already exists:
1. go to the top of the page and click on the search button (or better yet ADVANCED SEARCH!!!!1)
2. find said information (it's all there!)
3. compile said information
4. make your post
5. don't ask people who have already been over it 10x to rehash the same old dead horse arguments

A$$hole is famous for doing this, finding a good piece of information from long, long ago and then putting it in a new post to bring it back to the forefront and give us something to think about.

Not trying to be a dick here (well a little) but you can't expect other people to do everything for you, especially if they have already contributed the information you seek.


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## remeolb (Nov 6, 2009)

What you all are saying makes perfect sense. I guess we should start here; Does anyone think a thread like what I've mentioned would be worth putting together? And is anyone willing to help? If the thread has any chance of getting "stickied" I'm sure it would need the support of some significantly more veteran members than myself. For example, the ones that know of myths that I didn't even know were myths.


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## MiniVanMan (Jun 28, 2005)

remeolb said:


> What you all are saying makes perfect sense. I guess we should start here; Does anyone think a thread like what I've mentioned would be worth putting together? And is anyone willing to help? If the thread has any chance of getting "stickied" I'm sure it would need the support of some significantly more veteran members than myself. For example, the ones that know of myths that I didn't even know were myths.


This would be a good start. A lot of myths debunked in this thread here.

http://www.diymobileaudio.com/forum/diyma-tutorials/37931-important-technical-threads-list.html


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## Lars Ulriched (Oct 31, 2009)

BeatsDownLow said:


> Is there really valid data that show damping factor doesnt contribute to much. I guess by valid data I mean a rig set up with lasers and stuff to read the cone movement accurately? I am not stating it does or doesnt, but without some high dollar test setup I dont think anybody can claim it does either way


Oh no  ....come on...tell me that damping factor is important....I bought Arc Audio and Steg becos the Damping Factor is so high e.g >1K..... Tell me did i make a mistake?


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## Lars Ulriched (Oct 31, 2009)

WRX/Z28 said:


> Old school is still better... even if it's just for the "cool factor"


I think the myth about the greatness of olllldddddddddddd school which already > 15 years old is all about selling the old stuffs.....or else no one is buying...


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## chad (Jun 30, 2005)

Lars Ulriched said:


> Oh no  ....come on...tell me that damping factor is important....I bought Arc Audio and Steg *becos *the Damping Factor is so high e.g >1K..... Tell me did i make a mistake?


yer kidding right? that's the only reason?


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## WRX/Z28 (Feb 21, 2008)

Lars Ulriched said:


> I think the myth about the greatness of olllldddddddddddd school which already > 15 years old is all about selling the old stuffs.....or else no one is buying...


You go on thinking that...


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## Lars Ulriched (Oct 31, 2009)

chad said:


> yer kidding right? that's the only reason?


Not really...but ppl sold me the idea and i bought it....that damping factor is the number too look when buying amp for bass and mid bass.....  so I got it wrong?


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## MiniVanMan (Jun 28, 2005)

Lars Ulriched said:


> Not really...but ppl sold me the idea and i bought it....that damping factor is the number too look when buying amp for bass and mid bass.....  so I got it wrong?


Welcome to the world of jaded car audio veteran enthusiasts.


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## ChrisB (Jul 3, 2008)

One of my major misconceptions was believing this guy:


Nameless_Person said:


> I definitely would not invest in a class D amp of ANY brand. A, number one, they don't last long, reliability on a class D amp is poor to say the best, a year to a year and a half is the life span of most class D amps. Secondly, they sound like crap, they make sound not music. There is no definition or musicality to the amps.
> 
> You are never going to have quality sound in a two ohm load, even the best amps start sounding bad into 2 ohms! The physics of it is that every time the impedance is cut in half, distortion doubles, damping factor and headroom (SOUND QUALITY) is cut in half! Current draw from the battery and heat from the amp are doubled, and the life of the transistors and the amp are cut in half! NO *name edited out* amp will run into 2 ohms anyway, modified or not!
> 
> ...


Sadly, I have seen different people believing in that individual as well as being separated from their cash by him due to being sold on modifications for 20 year old relics.

Too bad I deleted all my emails from him because there were some other doozies loaded with hype and BS.


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## audiogodz1 (Jan 5, 2010)

tvrift said:


> That all amps sound the same in real life situations.


If it weren't for companies pre-equalizing the inputs that would be true. Unfortunately you have to make a decision when designing the amp. Some put bass and treble knobs on it and let you decide, others make the capacitors and resistors in the section a fixed rate of their choosing. On those amps the fixed equalization is unavoidable and must be worked back out with an external EQ, but in the literal sense (which is what the persons forming the argument you posted) they would be wrong to say they all sound the same because they are unavoidably pre-equalized to whatever the designer wants. Therefore, they do not all sound the same. 

Outside interference can make anything possible, that's what makes lies become truth. It doesn't make it correct, it only makes it "possible".


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## rc10mike (Mar 27, 2008)

audiogodz1 said:


> If it weren't for companies pre-equalizing the inputs that would be true. Unfortunately you have to make a decision when designing the amp. Some put bass and treble knobs on it and let you decide, others make the capacitors and resistors in the section a fixed rate of their choosing. On those amps the fixed equalization is unavoidable and must be worked back out with an external EQ, but in the literal sense (which is what the persons forming the argument you posted) they would be wrong to say they all sound the same because they are unavoidably pre-equalized to whatever the designer wants. Therefore, they do not all sound the same.
> 
> Outside interference can make anything possible, that's what makes lies become truth. It doesn't make it correct, it only makes it "possible".


You know, I really wonder how many amps are pre-eq'd!


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## ChrisB (Jul 3, 2008)

tvrift said:


> You know, I really wonder how many amps are pre-eq'd!


Rockford Fosgate, MTX, Kicker, and Linear Power are a few amplifiers off the top of my head that employ characteristics to intentionally color the sound of their products.

Some Rockford Fosgate amplifiers with a flat input measure to have a Fletcher–Munson equal loudness contour on the output section.

ETA:


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## Dryseals (Sep 7, 2008)

ChrisB said:


> Rockford Fosgate, MTX, Kicker, and Linear Power are a few amplifiers off the top of my head that employ characteristics to intentionally color the sound of their products.
> 
> Some Rockford Fosgate amplifiers with a flat input measure to have a Fletcher–Munson equal loudness contour on the output section.
> 
> ETA:


Interesting, I guess I took for granted they all tried to stay flat. Then again, I can't remember seeing any specs like the old days 20-20KHZ +-1db


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## 89grand (Nov 23, 2006)

Granted, that graph looks worse than it really is. It's still +/- 1.5db, but I still don't like the idea behind it.


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## rc10mike (Mar 27, 2008)

Ive tried MOST of the top 2kw range sub amps around. For the most part, they sound the same, except for my JBL BPX2200.1 which seemed to be MUCH louder in the 60hz region than my other amps. The gain didnt matter, the 60hz region was much more apparent. I wonder if that one has some sort of pre-eq....


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## ChrisB (Jul 3, 2008)

89grand said:


> Granted, that graph looks worse than it really is. It's still +/- 1.5db, but I still don't like the idea behind it.


BUT, that was with 2 volts RMS of output. How skewed do you think it will be at full output or normal listening levels?


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## 89grand (Nov 23, 2006)

ChrisB said:


> BUT, that was with 2 volts RMS of output. How skewed do you think it will be at full output or normal listening levels?


I'm not defending the ****ty amp, but whether it's at 2 volts out or 20, it should remain the same. In other words, it's subtle, but still shouldn't be there.


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## WRX/Z28 (Feb 21, 2008)

No way dudes! A little birdie told me that all car amps sound the same!  heehehhe


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## 89grand (Nov 23, 2006)

WRX/Z28 said:


> No way dudes! A little birdie told me that all car amps sound the same!  heehehhe


Well, they do unless a designer purposely colors it's frequency response, which they shouldn't do.

Any half way decent amplifier should do nothing but amplify.


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## Dryseals (Sep 7, 2008)

89grand said:


> Well, they do unless a designer purposely colors it's frequency response, which they shouldn't do.
> 
> Any half way decent amplifier should do nothing but amplify.


Agreed, but here it is 2010. Sales!!!
Back in the 70's spec were published a bit different, each manufacturer was free of their own will to publish what they wanted. There were a few police out there, magazines, who do actual testing. For a few years it got kind of ugly, then in the early 80's it slipped and fell into these wordy reviews that said nothing about the gear, just some ones opinion.

It would be nice to have a site who truely tested specs in an unbiased manner. It became a trend, big paid for ads and walla, next month was a wordy review praising the gear.


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## ChrisB (Jul 3, 2008)

I remember when Grizz Archer posted the specs for the new Soundstream Reference amplifiers BEFORE their release, +/- 3 dB from 20 Hz to 20 kHz. What did he do when certain people laughed at that frequency response plot? He had the web team remove that spec from the website.


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## circa40 (Jan 20, 2008)

I dont know much validity there is but here's a review on RF amps. The reviewer indicates that RF does add bass boost to the signal. I would venture to say that its RFs sonic signature? 

RF vs PG, The Real Deal!


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## LunarDD (May 17, 2009)

ChrisB said:


> One of my major misconceptions was believing this guy:
> 
> 
> Sadly, I have seen different people believing in that individual as well as being separated from their cash by him due to being sold on modifications for 20 year old relics.
> ...


 That quote from (nameless person) is very funny!!!
For some brands that stuff is far from true!


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## chad (Jun 30, 2005)

LunarDD said:


> That quote from (nameless person) is very funny!!!
> For some brands that stuff is far from true!


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## MiniVanMan (Jun 28, 2005)

chad said:


>


I need to change my pants now.


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## chad (Jun 30, 2005)

Next time you are in the area I'll let you touch one. That's a bad motherfucker.

sumbitch does complex load detection can can even tell you when a driver IN AN ARRAY is beginning to fail.


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## MiniVanMan (Jun 28, 2005)

chad said:


> Next time you are in the area I'll let you touch one. That's a bad motherfucker.
> 
> sumbitch does complex load detection can can even tell you when a driver IN AN ARRAY is beginning to fail.


Can I **** it? I'll wear a condom, especially since I know you've had your dick all over that thing as well.


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## chad (Jun 30, 2005)

I have not touched it with my dick yet, I think big ugly Bill has however.


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## eustache (Mar 21, 2010)

chad said:


> Sealed enclosures for SQ.


My knowledge in the area is minimal, but I would be very interested in the evidence to support this, one way or the other. 

I have just been advised by more than one installer that Sealed enclosures are best for SQ. The sub manufacturers seem to agree.


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## chad (Jun 30, 2005)

did that installer or the manufacturer say why?

they re easier to build, less likely to screw up.


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## eustache (Mar 21, 2010)

fourthmeal said:


> Big subs are "slower" , small subs are "tighter".
> .


I have been advised that 2 6" subs (JL Audio 6W3v3) wil give a fast agile base - seemed convincing enough to me.

Does anyone agree/disagree?


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## MiniVanMan (Jun 28, 2005)

eustache said:


> I have been advised that 2 6" subs (JL Audio 6W3v3) wil give a fast agile base - seemed convincing enough to me.
> 
> Does anyone agree/disagree?


That's all it takes to convince you of something? 

I don't know if I can compete with that detailed, and technical of an analysis.


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## ChrisB (Jul 3, 2008)

LunarDD said:


> That quote from (nameless person) is very funny!!!
> For some brands that stuff is far from true!


Tell me about it. I guess my cousin's MTX 81000d is broken because he purchased that in 2001 IIRC and it is still being used till this very day. One to 1.5 years of useful life, eh?

As for 2 ohms... I tried a plethora of amplifiers at 2 ohms versus the Ell Pee 5002 @ 8 ohms. Maybe I am deaf, but I could tell no loss in sound quality, headroom, or any of that other jazz. In fact, just purely going by ear, the old school, loaded with ess que fairy dust, amp from 1991 was the *WEAKEST* of the bunch! Granted, I only tested against a Lunar L2125, Crossfire BMF 1000d, Clarion DPX1851, a Rockford Fosgate Power 1000bd, and a few others I have forgotten about that were 2 ohm stable on a 13w6v2.

I could tell you which amplifier was harder on my electrical system though... The circa 1991, high voltage, ess que, sonic bliss, Linear Power 5002 sucked the ever living life out of my 2006 Rustang GT's electrical system. Granted I only have a 160 amp alternator with an Optima Red top, but that amp was the only one to make my stock voltage meter move like an inverse VU meter to the beat of the music.

Oh snap, there I go with my anti-old school rant again.... I must call my therapist to get over my PTSD of believing the hype and BS spewed fourth from the nameless person who only cared about MONEY!


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## audiogodz1 (Jan 5, 2010)

chad said:


> did that installer or the manufacturer say why?
> 
> they re easier to build, less likely to screw up.


In todays world of 500 ounce motors and 3kw amps it likely matters less, but any old school equipment can benefit from the cone control provided by the sealed box. Motors were much smaller (80 ounces double stacked was HUGE), very few vented their VC's and most VC's were 1.5 inches, amps were out there in the 1kw range, but the hottest amp on the block was 600 watts and most ran about that much in the trunk. I think the most important thing to realize is that if you run "todays" equipment you run by todays rules, if you run yesterdays equipment you run by yesterdays rules. 

Some of the "myths" in this thread are perfectly applicable for yesterdays equipment, but "outdated" for some of todays equipment. It doesn't necessarily point to todays equipment being better, it means it is more capable. SQ hasn't been a hot button for manufacturers in over a decade, mostly efficiency.

At one time this was Rockfords double stacked monster.


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## chad (Jun 30, 2005)

Speakers have been used in vented enclosures LONG before the heyday of car audio, they were powered by larger amplifiers and had smallish motors. they sounded great.

IN FACT it was not till the days of shoving a kilowatt at a driver in an enclosure the size of a shoebox did this myth develop as far as I can see.... blame the solobaric.


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## audiogodz1 (Jan 5, 2010)

chad said:


> Speakers have been used in vented enclosures LONG before the heyday of car audio


Powered by a completely different source at a different ohm under different frequencies with lightweight cones made from paper which makes the motors size needs MUCH different.

I can run an IB loudspeaker WOOFER on 100 watts and blow my ears out, V/S 300 watts on a subwoofer to do the same work due to the heavy cone and larger motor.

Cones went from paper to kevlar coated, polyurethane, whatever else when old school crossed into new school. Cones got a LOT heavier. Things changed. Old school/new school.


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## chad (Jun 30, 2005)

source does not matter, impedance does not dictate motor strength, same frequencies.


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## audiogodz1 (Jan 5, 2010)

I like ya, but..... you're wrong. That's pretty much it.  Man has the brazen nuts to think he can control nature, which is why CERN is going to fail. Fact is laws of physics still apply no matter how hard you try to out think it. You can't sling a heavy ass Kevlar coated cone on a large magnet as accurately as a lightweight pressed paper cone on a smaller motor on the same wattage. As cones and motors have grown in mass, so have amp sizes. That part is all that has stayed relative. The old stuff was still too small in motors and wattage until around the time that solobaric you mentioned came along and everything started changing. That's when technology caught up and what was insufficient and needed help from things like sealed boxes changed and started to be able to "take care of itself". There's a threshold. You are not seeing the line.


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## Oliver (Jun 25, 2007)

audiogodz1 said:


> Powered by a completely different source at a different ohm under different frequencies with lightweight cones made from paper which makes the motors size needs MUCH different.


I prefer the DD cone and some ample power,[SAZ 1500 D] with my speaker wired at 2 Ohms in series


> eschreibung
> Digital Designs DD 9512 g
> DVC4-Variante mit 2x 4 Ohm Doppelschwingspule
> 
> ...


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## vrdublu (Apr 13, 2009)

ChrisB said:


> How about a certain brand that advertises 50x4 OR 325x2 all on 25 amps of fusing. 200 watts RMS I can almost believe with that fuse level but there is NO WAY I believe 650 watts RMS on 25 amps of fusing.
> 
> If you can find one of those amps, they still go for $700 to $750 which I find even more shocking...


How about 6x150rms on a 30A fuse running a sub bridged on 2 channels? Yes it can be done and it is being done. Class "D" amp by ZED !!


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## benny (Apr 7, 2008)

vrdublu said:


> How about 6x150rms on a 30A fuse running a sub bridged on 2 channels? Yes it can be done and it is being done. Class "D" amp by ZED !!


********. 30A at 12V might float 6x*50*W, but certainly not 6x*150*W.


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## ChrisB (Jul 3, 2008)

How did they find a way to violate Ohm's law? 

Volts X Amps X % efficiency = Watts.

14.4v x 30 amps = 432 watts!

For that amp to make 6x150 it would have to be 208% efficient.

Edit: My math may be off because I am still on my first cup of coffee, so I will check it later. In the meantime, I am waiting for the Zed band wagon riders to hop on board and say how Zed is a genius because HE figured out a way to create power.


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## vrdublu (Apr 13, 2009)

ChrisB said:


> How did they find a way to violate Ohm's law?
> 
> Volts X Amps X % efficiency = Watts.
> 
> ...


My bad that was my mistake, it's a 40A, OK !! This is what I'm running, this is what Zed claims, go argue with him. All I can say is it makes my 8W7 pop without clipping, and I'm running a 3-way active front. Here's a link to save you the trouble http://www.zedaudiocorp.com/PDF/ZedManual-A.pdf BTW the ZED amps are not internally fused, so this is a 40A at the battery.


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## chad (Jun 30, 2005)

that's still 576 watts.


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## ChrisB (Jul 3, 2008)

Another misconception: Zed is an uber elite audio gawd who figured out a way to generate power! 

I keed, I keed.......:laugh: :laugh4: :laugh3: :laugh2:


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## Luke352 (Jul 24, 2006)

If you read the manual Zed believes in under fusing to some degree, he puts it something along the lines of music is dynamic so you don't need a fuse large enough to handle the full sine wave producing current draw because the amp will never draw that much current playing music so it's much safer to use a smaller fuse offering greater protection for the amp and then if you find you blow the fuse then put a larger one in as necessary.

Also check AUDISON they do exactly the same thing some of there amps are underfused compared to there power ratings, but they also suggest different fuse sizes for lower loads etc... So ZED isn't the only company doing this, I'm sure there are some other companies doing this aswell, which is why calling ******** on amps because of the fuse fitted can leave you with egg on your face sometimes.


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## MarkZ (Dec 5, 2005)

100A anl fuse.









That's how.


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## sqshoestring (Jun 19, 2007)

I like old school 'colored' amps just for that reason, the less EQ I need the better. If they have some EQ in them that work to my advantage, I like it. Plus some of them clip nicer since I don't always use huge amps. I've not used an expensive newer amp, but the cheap/mid priced ones tend to clip ugly.

Now I prefer a class D on >300rms subs and only use old amps on mid/highs so power is not really an issue. The good ones tend to be overbuilt that is why they are still here, they work just as well as new ones far as SQ, and are easy to repair. One other thing is some of them look like real amps, could be a nostalgia thing, but a finned black thing is better IMO. The few I tested do around rated power, soon I can test more once I figure out how to fit another huge old power supply on my shelves. I would not pay what they want for linear powers, but you can pick up some old amps that are built like bomb shelters for good prices so why not use them instead of some new Chinese amp with all the cheapest parts and labor...unless you have some special need.

Nobody said "peak power", the calling card of cheap stuff. My new pyle subs are just 1000w, they don't say anything else. I would get a 1000w pyle amp and load test it to find out what that is, but suppose I don't really care. I know a 1000w insignia is 2x115rms, so is that 460rms? lol. My model says 200rms is enough.

I always figured if you wanted real dampening find a servo sub setup.


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