# Speaker sensitivity



## David45 (Sep 7, 2012)

Is it just me or a lot of people don't seem to care so much about efficiency in the car audio industry? Matching components to achieve a reasonable decibel level (with some headroom) rather than focus on specific power requirements and the likes? 
1st post! I can send PMs now 

Cheers


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## Hanatsu (Nov 9, 2010)

No they tend to build woofers made for small enclosures and moderate low extention and according to hoffmans iron law you can't have great sensitivity then. Power is cheap nowadays so that's the tradeoff.


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## sweefu (Jun 26, 2011)

Hanatsu said:


> Power is cheap nowadays so that's the tradeoff.


Cheap power is cheap! Good power still costs a bit of money.. I do consider speaker sensitivity when selecting a driver, though it's only a concern for me if the sensitivity is very low.


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## BuickGN (May 29, 2009)

I love an efficient sub setup. my subs are 91db 1w/1m and they're infinite baffle. The actual efficiency isn't that great compared to some old school subs but pretty good for a modern sub. The efficiency with the sub and enclosure type combined is crazy. With only 250w each, they're quite a bit louder than my 12W6s in a sealed box on 1,200w. For me, efficiency is one of the more important things because there are other positives that come along with using less power for a given output, not to mention you're less likely to have to spend money upgrading the alternator and wiring. 

My front stage isn't inefficient but it's not efficient either, comnpared to other components out there. Kind of average in that department. It's no wonder why my 15s have 500w but my front stage has 1,000w. I love the sound, the tonality, and pretty much everything about my Dyns so it was a sacrafice I was willing to make but it would be really cool to have every driver in the front stage over 91db efficient. 

I've considered an all pro-audio or "near" pro audio build with Acoustic Elegance drivers. I threw together a theoretical system and with their 18" woofers, some 10" midbass, 6" midrange, the driver with the least efficiency was still 97 or 98db. It's pretty crazy that it could be decently loud with 1w to each driver. 

But yeah, I agree with the first post and I've posted about it myself several times. I think people approach this stuff completely backwards. How many times do we see a thread where someone is looking for a sub that "will take 1,000w" instead of an efficient sub that only requires 250w to do what others do with 1,000w. Or at least when asking about a sub, has SPL potential as one of your qualifications instead of how much power it can take. One sub might produce 145db on 1,000w while another might produce 130db on the same power. One of my favorite things is to blow people's minds and really crank on my subs and afterwards let them know it's pushing 250w at best, likely less than 250w each. The output in the lower 30hz region with this tiny 500w sub section of my 900/5 amp is literally comprable to many sealed sub setups I've heard with over 1,000w on them.

Power is kind of cheap but for a quality amp, you're still paying a fair amount for high power. Why not go with an efficient setup and retain the factory charging system and never have to worry about power compression and the added distortion that comes with high power.


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## Danometal (Nov 16, 2009)

BuickGN said:


> I love an efficient sub setup. my subs are 91db 1w/1m and they're infinite baffle. The actual efficiency isn't that great compared to some old school subs but pretty good for a modern sub. The efficiency with the sub and enclosure type combined is crazy. With only 250w each, they're quite a bit louder than my 12W6s in a sealed box on 1,200w. For me, efficiency is one of the more important things because there are other positives that come along with using less power for a given output, not to mention you're less likely to have to spend money upgrading the alternator and wiring.
> 
> My front stage isn't inefficient but it's not efficient either, comnpared to other components out there. Kind of average in that department. It's no wonder why my 15s have 500w but my front stage has 1,000w. I love the sound, the tonality, and pretty much everything about my Dyns so it was a sacrafice I was willing to make but it would be really cool to have every driver in the front stage over 91db efficient.
> 
> ...


Nice. I agree that it seems less than practical to have to spend an additional $400 for an alternator that can juice your monster amp that your monster inefficient sub(s) requires.

To me, a 1W/1M spec of like 85 dbs or less is a deal breaker.


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## Calum (Aug 13, 2008)

Danometal said:


> Nice. I agree that it seems less than practical to have to spend an additional $400 for an alternator that can juice your monster amp that your monster inefficient sub(s) requires.
> 
> To me, a 1W/1M spec of like 85 dbs or less is a deal breaker.


That's pretty much my cut off to. When people ask I try to explain that max input wattage does not equal volume, but it normally falls on dead ears.


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## sqshoestring (Jun 19, 2007)

I'm in the middle because with pro audio you have such a nasty FR you need a lot of processing to get it flat so I don't want to mess with that, then with inefficient stuff you need all kinds of power. So I aim for the center. In the past I ran a lot of lower power but better brand name speakers (auto speakers). Had good luck with them only once in a while a tweeter would pop on me, sound could be really nice if you picked the right ones. They could get loud pretty easily.


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## BuickGN (May 29, 2009)

Calum said:


> That's pretty much my cut off to. When people ask I try to explain that max input wattage does not equal volume, but it normally falls on dead ears.


You think that's hard, try explaining that power means nothing, only excursion matters for SPL with a sealed or IB sub. If a sub hits full excursion with 100w or 1,000w, it's going to have the same SPL.


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## t3sn4f2 (Jan 3, 2007)

sweefu said:


> *Cheap power is cheap! Good power still costs a bit of money.*. I do consider speaker sensitivity when selecting a driver, though it's only a concern for me if the sensitivity is very low.


:bash:


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## sweefu (Jun 26, 2011)

t3sn4f2 said:


> :bash:


I'm sorry, I'm not following :/
I have yet to come across 'cheap' good quality amplifier, awesome old school gear sometimes pops up cheap but more than often I find it's not in very good condition (I'm in Australia, not the US)

For me, good power comes from a well made amplifier with low THD, a decent damping factor and a high signal to noise ratio, say
0.05% THD or less
200 - 300 damping factor +
S/N 100dB +

Or maybe I have a different view for what is cheap.


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## TOOSTUBBORN2FAIL (Jan 31, 2011)

sweefu said:


> I'm sorry, I'm not following :/
> I have yet to come across 'cheap' good quality amplifier, awesome old school gear sometimes pops up cheap but more than often I find it's not in very good condition (I'm in Australia, not the US)
> 
> For me, good power comes from a well made amplifier with low THD, a decent damping factor and a high signal to noise ratio, say
> ...


There's nothing wrong with spending a ton of money on overkill amps, if that's what you like, but there are much cheaper amps that would sound just as good to your ears, if you listened blind. In the end, what you see is what you hear.


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## Juls1 (Sep 8, 2012)

Trying to explain to people that high power handling simply means "high power consumption" not "more volume" is incredibly difficult.

With a world that everything is about more watts.. 

EG: you go to the shops, to buy a vaccum, you can buy a 2400W Vaccum for $69, or a 1000W Vaccum for $300, people think the $69 vaccum is a bargain because it has more power... err no.. it "USES" more power!! it's not necessarily more powerful at all, in fact it's probably less powerful than the 1000W vaccum!! it can just burn up/waste 2400W of energy, how much of that energy is turned into sucking is almost certainly very little.

The same goes for subwoofers or speakers generally for that matter, the power handling figure is really, not that useful, particularily since there is "NO STANDARD" in terms of measuring how much power a driver can take, is the 1000W rating, Thermal? or Mechanical? what frequency is that rating at? 

EG: A Subwoofer might be rated at 1000W, but they don't tell you thats Thermal handling at 1khz. It's Mechanical power handling at 40hz might only be 250W. (which is quite likely). 

If a Subwoofer had a "mechanical" power handling of 1000W, In order to get that power to it, you'd need at least 120 if not 150amps of power, most cars only have 60amp alternators, and batterys not capable in excess of 100A draw. 

Effeciency in my mind is the most important thing for car audio, especially for SQ enthusiasts because the system must not be stressed, system stress, be it the power supply or the amplifier equals distortion. Highly effecient drivers don't need heaps of power, therefore you don't have to waste precious energy driving your system. 

Sadly though, the Effeciency rating of 1W/1M or 2.83V/1M does not tell the whole story at all, I would like to see a power requirement measurement across it's SPL range, some drivers might be hugely effecient at 1W, but hopeless when you get to 100W+ Diminishing returns are more common than we might think.

A High Effeciency rating, combined with a high power rating should be looked at with great suspicion. 

In my mind, 1000W RMS subwoofers are pointless waste of energy for anything other than SPL competition, they don't actually sound good so there is no real point in running them daily, unless your a sucker for marketing numbers.

Many people claim greatly improved sound by running very high powered amplifiers, sometimes 3-4 times more than the rated power of the driver, it's certainly possible "IF" the quality of the amplifier is equivalent or better than the amp previously run, the reason this would happen because higher powered amplifiers are more effecient running at 25% than a lower power amp running at 90%. 

For example a 1000W amp pushing out 500W might be able to do this at 90% effeciency, this means it draws 47amps @ 12V, However a 500W amp driving 500W would only achieve around 50% effeciency meaning to driver 500W it draws from your alternator/battery about 83amps @ 12V..

What happens now though is the real kicker, you see if your alternator and battery are struggling to achieve 83amps, The voltage will drop, if the voltage drops to 10V, this increases the amplifiers power requirement to 100amps!! Which just compounds the problem and the voltage drops further, the amp does not get the power it needs and in turn it cannot provide the 500W your subwoofer or speaker is asking, this means the amp will clip/distort and the sound will be compromised.

Effeciency is everything and..

the world is watts mad...

Juls


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## minbari (Mar 3, 2011)

Juls1 said:


> Trying to explain to people that high power handling simply means "high power consumption" not "more volume" is incredibly difficult.
> 
> With a world that everything is about more watts..
> 
> ...


alot of truth here!

I will add some simple math to this. if you have a sub that handles 250 watts just find and puts out 125db in your car. going to 1000 watts will only gain you a MAX of 6db more. unless you are an SPL competitor, this is pretty useless. no one listens to music at 125 db anyway, so getting to 131db is all just bragging rights. wont actually improve the sound. for those bragging rights, you chew up alot more current and spend alot more money.

these days watts are pretty cheap. an avg 1000 watt amplifier is only $150-200. but the point remains the same.


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## MarkZ (Dec 5, 2005)

sweefu said:


> 0.05% THD or less
> 200 - 300 damping factor +
> S/N 100dB +


There are $100 bargain basement amps that meet those requirements.


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## BuickGN (May 29, 2009)

Juls1 said:


> Trying to explain to people that high power handling simply means "high power consumption" not "more volume" is incredibly difficult.
> 
> With a world that everything is about more watts..
> 
> ...


Don't most amplifiers get more efficient the harder you push them, not less efficient?

The more powerful amps give the headroom necessary for dynamic peaks in music which can require 2-3x the average power.


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## minbari (Mar 3, 2011)

BuickGN said:


> *Don't most amplifiers get more efficient the harder you push them, not less efficient?*
> 
> The more powerful amps give the headroom necessary for dynamic peaks in music which can require 2-3x the average power.


think you are right on that one. I know Class A/B for sure are more efficient flat out than near no output. they go from like 25% with moderate output to 50% flat out. (general numbers)


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## Juls1 (Sep 8, 2012)

My apologies for my error, seems what your saying is true, particularly for D class amps. I will try to do more research next time.

Cheers
Juls


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## sqshoestring (Jun 19, 2007)

minbari said:


> think you are right on that one. I know Class A/B for sure are more efficient flat out than near no output. they go from like 25% with moderate output to 50% flat out. (general numbers)


Yes they do.

So just get a class D that runs 75% or better all the time if you want efficiency. Its really not much of a point if you use efficient speakers because nobody cares about the power a class AB 100w (or less) amp takes....that is all you need on those efficient speakers. The only problem is efficient speakers can be a pain in the rear to tune that is why nobody uses pro sound speakers in cars for the most part. It certainly can be done if you can fit the larger ones in your car. My unknown efficiency 1,000w pyle subs have hardly any EQ on them and since I have a pair of 15s output is not an issue at all for me. That package works for me and IMO is key for any system: you use what is going to work. Though nothing wrong with trying this or that, or a system with prosound drivers if you are up to it. I used to run cheaper (but good brand name) lower power speakers all the time with good results. They get loud on not that much power, but can puke once in a while lol.


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## squeak9798 (Apr 20, 2005)

Juls1 said:


> In my mind, 1000W RMS subwoofers are pointless waste of energy for anything other than SPL competition, they don't actually sound good so there is no real point in running them daily, unless your a sucker for marketing numbers.


This is by far the worst generalization I've read in a long, long time.


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## minbari (Mar 3, 2011)

squeak9798 said:


> This is by far the worst generalization I've read in a long, long time.


What's bad about it? High wattage subs have stiffer suspensions in general and require higher wattage to reach xmax than a lower wattage sub. 

Sent from my phone using digital farts


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## BuickGN (May 29, 2009)

I would rather have a light cone, soft suspension and a high efficiency rating. My subs feel like they forgot the spider, the suspension is so soft but they require so little power to get loud. Screw power, give me sensitivity.


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## squeak9798 (Apr 20, 2005)

minbari said:


> What's bad about it? High wattage subs have stiffer suspensions in general and require higher wattage to reach xmax than a lower wattage sub.
> 
> Sent from my phone using digital farts


Read what he said, your response to my post has absolutely *nothing* to do with what he said. 1000w subs can't sound good? SPL only? Really? Some of the lowest distortion drivers on the market are designed to handle close to or more than 1kw. Guess somebody forgot to tell them that since it was rated at 1kw it couldn't possibly sound good  That's an extremely ignorant statement and no matter how you try to rationalize it, it's simply wrong.

Also, your generalization is relatively off base as well. Power handling is frequently rated as thermal power handling, not necessarily mechanical since mechanical power handling is dependent upon the enclosure. The correlation between being rated at 1kw and having a "stiffer suspension" doesn't _inherently_ exist. Look at specs such as Fs in relation to Mms to determine how stiff the suspension is or isn't, not the power handling. Take, for example, the Exodus Shiva-X2 which was rated at 1kw (and by the way, sounds _extremely_ good) but had an Fs of 21hz, which indicates a rather compliant suspension considering it's reasonable 206g Mms. And that was literally the first sub that came to my mind, I didn't have to look hard to find it. Other 1kw subs might have been designed with a stiffer suspension because that _met their specific design goals_ (target T/S parameters, target enclosure size and response, etc), *not* because they have a 1kw power handling rating.

I've only seen a few people mention this and it's another terrible generalization. People are talking about output compared to power input and sensitivity, but they are forgetting to talk about output over the intended bandwidth and the available enclosure space/enclosure design. Just because the sensitivity is higher doesn't mean it's going to be louder _over the desired bandwidth_, even if we use the same power on both drivers, in the intended enclosure or available space....or even at all. Hoffman's Iron Law. 

Something else people are forgetting to mention is power compression. A higher sensitivity might allow higher peak output on the same power in a modeling program, but if the driver is also experiencing significantly more power compression because it's designed to thermally/mechanically handle less power then guess what? The audible difference just dropped _substantially_, possibly enough that there wouldn't be an audible difference in peak output but the lower sensitivity driver could end up with audibly more low end extension.

Related to that, I don't think many people are considering the fact that rated power handling is not a power _requirement_. Output in a given enclosure is affected by the mechanical behavior of that particular enclosure and desired output level, not the rated power handling. Considering you only gain 3db by doubling power, and that ignores power compression, you could halve that 1kw power rating to 500w and end up with fairly minor audible difference in output, not to mention less power compression. 

Since we are generalizing, I'll also point out there that while higher sensitivity subs might not need as much power to reach Xmax (at SOME frequencies), they also generally have a _lower Xmax_ than a higher power handling sub which means that the lower Xmax sub will have also have _lower potential output capabilities_. Along with that, for a given excursion level it's possible the higher Xmax sub will end up having lower distortion at that excursion level since it's using a smaller proportion of it's potential excursion capabilities at any given excursion level, _in addition_ to the lower power compression mentioned previously. 

My point is there is nothing but gross over-generalizations and half-truths being tossed around in this thread. Great for you if you've had good success with higher sensitivity drivers, I'm happy for you. But it worked for you under a specific set of circumstances with your specific goals, that's not necessarily going to be the case for everyone. Engineering is basically finding the best set of compromises and trade-offs for a given end goal. When someone designed a higher sensitivity driver or when you selected one for your stereo you are not only gaining something you desired but you are also, by default and necessity, giving something _else_ up. A lot of comments in this thread make it sound like it's all gain with nothing to lose. That's simply not the case, and it's a fact of physics. To you the trade-offs might be worth it, to others or in different situations it's not. 

And the comment about 1kw subs being SPL only and not being able to sound good....._pffftt_. That's simply hogwash.


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## AKheathen (Sep 10, 2011)

sweefu said:


> I'm sorry, I'm not following :/
> I have yet to come across 'cheap' good quality amplifier, awesome old school gear sometimes pops up cheap but more than often I find it's not in very good condition (I'm in Australia, not the US)
> 
> For me, good power comes from a well made amplifier with low THD, a decent damping factor and a high signal to noise ratio, say
> ...





BuickGN said:


> Don't most amplifiers get more efficient the harder you push them, not less efficient?
> 
> The more powerful amps give the headroom necessary for dynamic peaks in music which can require 2-3x the average power.


yes, and no. amplifiers do get the most efficient when they are run near their most output, otherwise, you can see around 25% efficiency in the normal operating range. however "headroom" is depicted in how the amplifier deals with momentary current demands. some do this by having a large capacitance bank on the rails that will not deplete, or greatly sag during these "peaks" and others, like old school hcca amps, simply do not flinch when asked for more current. of course, i am assuming what you mean and could be mistaken, but it sounds like you are looking a t the "max" rating, as most look at, even when going solely by rms, as you should. take the x-plode/similar amps for example. that big rating is reliant on that high voltage rail charge, but the reason it doesn't mean squat, and actually leads to a poor "bubbly" output sound to the 1/4 max rated rms is that it is a momontary burst of power. where things get fuzzy, is that no one states how long it is sustained, and it could be depleted in the instance the driver just starts to move, or it can las an entire "thump" and rte-charge in time for the next.


sqshoestring said:


> Yes they do.
> 
> So just get a class D that runs 75% or better all the time if you want efficiency. Its really not much of a point if you use efficient speakers because nobody cares about the power a class AB 100w (or less) amp takes....that is all you need on those efficient speakers. The only problem is efficient speakers can be a pain in the rear to tune that is why nobody uses pro sound speakers in cars for the most part. It certainly can be done if you can fit the larger ones in your car. My unknown efficiency 1,000w pyle subs have hardly any EQ on them and since I have a pair of 15s output is not an issue at all for me. That package works for me and IMO is key for any system: you use what is going to work. Though nothing wrong with trying this or that, or a system with prosound drivers if you are up to it. I used to run cheaper (but good brand name) lower power speakers all the time with good results. They get loud on not that much power, but can puke once in a while lol.


fyi, a "class d" amp that runs 75% plus all the time does not exist to my knowledge, however, what is close is either class g, or h, which is similar, but won't go into that now. a pyle sub probably can be tuned just fine, like many drivers, the big thing with pyle is that the manufacturing makes it a "pile" of you know..... you just have to take risk that something on it isn't going to break, which there is no problem doing, given the price, and that you are fine with it. i think they have low bl, though... i, 100% agree on cheaper, lower powered subs, mostly big box names, as they can respond with little power, even though they may not like high pressure.


squeak9798 said:


> Read what he said, your response to my post has absolutely *nothing* to do with what he said. 1000w subs can't sound good? SPL only? Really? Some of the lowest distortion drivers on the market are designed to handle close to or more than 1kw. Guess somebody forgot to tell them that since it was rated at 1kw it couldn't possibly sound good  That's an extremely ignorant statement and no matter how you try to rationalize it, it's simply wrong.
> 
> Also, your generalization is relatively off base as well. Power handling is frequently rated as thermal power handling, not necessarily mechanical since mechanical power handling is dependent upon the enclosure. The correlation between being rated at 1kw and having a "stiffer suspension" doesn't _inherently_ exist. Look at specs such as Fs in relation to Mms to determine how stiff the suspension is or isn't, not the power handling. Take, for example, the Exodus Shiva-X2 which was rated at 1kw (and by the way, sounds _extremely_ good) but had an Fs of 21hz, which indicates a rather compliant suspension considering it's reasonable 206g Mms. And that was literally the first sub that came to my mind, I didn't have to look hard to find it. Other 1kw subs might have been designed with a stiffer suspension because that _met their specific design goals_ (target T/S parameters, target enclosure size and response, etc), *not* because they have a 1kw power handling rating.
> 
> ...


best points to this thread yet. one thing i have not seen tossed around is bl. you can theorize all you want, but at least toss some specs around that really show what we are discussing. the bl is the rating, in short, that tells you how much power is applied as force. it is what effects all these parameters. low bl, and you need that big power to make noise. high bl, needs less. it is the force you speak of, basically, be it 100, or 10,000 watts. 

so, yah, i have played with different "sensitivity" drivers, and really consider it, but you have to look at all of the factors and understand them. this is why i am comfortable with dealing with the ever-so-minor frequency response curve deficiencies in delco speakers on low power within a db range that will not damage my hearing when listened to for long periods. may not live up to 250wrms fed drivers that could take it and give a near perfect flat response, but i'm fine with them in my daily for now, since they are perfectly "sensitive" enough to give me the 85hz+ at 20wrms i need to hear music. for demo, and other people, i reach further. actually, i am a big fan of the new infinity/jbl components and their performance on low power.


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## TOOSTUBBORN2FAIL (Jan 31, 2011)

Buick is talking about buying larger amps than needed, so the amps never stressed.


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## AKheathen (Sep 10, 2011)

Juls1 said:


> Trying to explain to people that high power handling simply means "high power consumption" not "more volume" is incredibly difficult.
> 
> With a world that everything is about more watts..
> 
> ...


TRUE, THERE IS NO REAL STANDARD, _EXCEPT FOR_rms. this basically means the clean signal you can feed it non-stop before thermal, electrical, or mechanical failure is potential. really, it is not too hard to spot. if max is 2x rms, it is pretty honest, and you can run that amount of power thermally for short stents. if it is 4x+, then it is a safe bet that a peice of wire somewhere in the circuit will blow apart over that power. in between, you can safely throw spurts or burps. it is real noce when it varies with enclosure, as those tell you the mechanical limitations


> EG: A Subwoofer might be rated at 1000W, but they don't tell you thats Thermal handling at 1khz. It's Mechanical power handling at 40hz might only be 250W. (which is quite likely).


not likely. some may do it rarely, but most do it before the -3db drop-off of the driver. it is more likely to be seen in cheap amplifiers, were the frequency is higher, yet not high enough for the components to start causing notable power loss, or signal degradation 



> If a Subwoofer had a "mechanical" power handling of 1000W, In order to get that power to it, you'd need at least 120 if not 150amps of power, most cars only have 60amp alternators, and batterys not capable in excess of 100A draw.


again, speculation. the simplest rule-of-thumb is 1a= about 10watts power, for more modern amps. old school amps can consume much more current. i just bought a battery yeasterday capable of about 1500a continuous for 5 seconds, without dropping below 11.8v.....



> Effeciency in my mind is the most important thing for car audio, especially for SQ enthusiasts because the system must not be stressed, system stress, be it the power supply or the amplifier equals distortion. Highly effecient drivers don't need heaps of power, therefore you don't have to waste precious energy driving your system.


again, the opposite. look at class"a" amps. much like some factory head/amps do, the speakers are brought up to a constant dc voltage. what this does is help to physically hold the cone solid in space and more-so comply to any and all signal it is fed to respond to. without it, a driver is free to spring back or vibrate on it's own. on top of that, it creates a counter-signal the amp may have to fight, given the timing of the next pulse. to do this, it takes a bit of energy that you do not get in sound, rather in silence, actually, which is good for sq, but takes form the total thermal power handling available, and efficiency of the amp



> Sadly though, the Effeciency rating of 1W/1M or 2.83V/1M does not tell the whole story at all, I would like to see a power requirement measurement across it's SPL range, some drivers might be hugely effecient at 1W, but hopeless when you get to 100W+ Diminishing returns are more common than we might think.
> 
> A High Effeciency rating, combined with a high power rating should be looked at with great suspicion.


what you are talking about would do little more than confuse 99% of customers with a 3d graph, and fall into the category of things best handled by 3rd party tests for avid enthusiasts...



> In my mind, 1000W RMS subwoofers are pointless waste of energy for anything other than SPL competition, they don't actually sound good so there is no real point in running them daily, unless your a sucker for marketing numbers.


still think that?



> Many people claim greatly improved sound by running very high powered amplifiers, sometimes 3-4 times more than the rated power of the driver, it's certainly possible "IF" the quality of the amplifier is equivalent or better than the amp previously run, the reason this would happen because higher powered amplifiers are more effecient running at 25% than a lower power amp running at 90%.


 already outlined typical amplifier efficiencies.... anyways, the claims come from the fact that most doing that successfully have put the time and research into the end result, and they are right. like class a amps, they have achieved greater driver control, meaning, the driver is better doing what you tell it, or "complying"



> For example a 1000W amp pushing out 500W might be able to do this at 90% effeciency, this means it draws 47amps @ 12V, However a 500W amp driving 500W would only achieve around 50% effeciency meaning to driver 500W it draws from your alternator/battery about 83amps @ 12V..


again, completely opposite. by the way, i work on repairing and upgrading amps, and have been repairing subs since before you could buy parts for them.



> What happens now though is the real kicker, you see if your alternator and battery are struggling to achieve 83amps, The voltage will drop, if the voltage drops to 10V, this increases the amplifiers power requirement to 100amps!! Which just compounds the problem and the voltage drops further, the amp does not get the power it needs and in turn it cannot provide the 500W your subwoofer or speaker is asking, this means the amp will clip/distort and the sound will be compromised.
> 
> Effeciency is everything and..
> 
> ...


a little view in how this works..... an amps efficiency and power transfer between power used, and power made relies on the transformer, usually the "torroid". it relies on an inductance rating,. much like sensitivity of a sub/speaker relies on bl for it's "efficiency"... the more voltage, the better the transfer. the less voltage dependent transfer, the less the current is hindered. same goes for the amount of current allowed to pass through the secondaries(powers the rails that feed the outputs). you are right, in that the lower the voltage drops, the more current the amp will use at the same level, but even 1/10th of a volt makes a big jump in efficiency. this is whay you can commonly see something like a "4k" 12v amp push near 10k at 16-18v (if it is capable of that voltage).... the math doesn't evactly add up on paper in simple math, but, if you know enough about the specific amp, and it's components (inductance/winding setup, p/s fet characteristics and [email protected] operating conditions, output thermal and frequency losses in conjunction with drivers, "damping" where aplicable, etc) then the extensive equasions will make sence. for now, take my word: this is how it works. don't take me wrong, as it is real obvious you are thinking about his with much effort, and the conclusions do make sense, but it just seems you have not also gone and researched exactly how this all works before posting. i started in the mid-90's, and still believe i have way too much to learn yet.


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## AKheathen (Sep 10, 2011)

sweefu said:


> I'm sorry, I'm not following :/
> I have yet to come across 'cheap' good quality amplifier, awesome old school gear sometimes pops up cheap but more than often I find it's not in very good condition (I'm in Australia, not the US)
> 
> For me, good power comes from a well made amplifier with low THD, a decent damping factor and a high signal to noise ratio, say
> ...


first, thd, is not all the same. to say amp "a" has 5% thd at 100wrms/4ohms, and amp"b" has 0.002%thd @100wrms/4ohms, could simply mean that amp b has 12 more watts, but amp a is rating what it needs to to get from [email protected]%thd to an advertised 100, so the silkscreen on the heat-sink does not lie. there are some amps out there that will double rms if you allow for up to 10%thd. dampening factor had, indeed been tossed around, but, really, there is something to it. it, simply is the ability for the amp to reject and/or overcome the power created by the speaker trying to return to neutral. in honesty, i don't think a speker/driver is even 10% efficient as a microphone signal "generator" as an actual microphone, so it is a real small factor, and, hence, tossed aside as gibberish rating... s/n ratio: sometimes there is something there, sometimes not. it depends on how they are rating it, per-manufacturer. i did this little experiment on another car audio site, and, guess what? i convinced most of the masses complete bs about it, and didn't really get some real solid challenge. basically, in short, it all varies from make-to model so there is no real standard. anything rated in "db" on an amp is bs. you could take a real weak bl, high mass, etc driver and run it up to the rated"db" with 75 watts, and see how much "db" of noise is present, or take an extremely sensitive driver to the same db at 5w and see how much is there. the same amp might rate both 50 and 250..


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## 04silverz (May 28, 2008)

sweefu said:


> Cheap power is cheap! Good power still costs a bit w.


I kinda disagree here. Iirc back in the day when I bought my Orion xtrpro2400 I think they were north of a grand retail (1200 sounds right). Seems to be quite a few options out there these days for less and more efficient. I know that's only one example but I feel it's applicable across the board
Now if you are talking the true higher end stuff, I can't answer that.


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## subwoofery (Nov 9, 2008)

BuickGN said:


> I would rather have a light cone, soft suspension and a high efficiency rating. My subs feel like they forgot the spider, the suspension is so soft but they require so little power to get loud. Screw power, give me sensitivity.


You have trunk - easiest way to go around "Hoffman's Iron Law", while keeping the trunk space to a maximum, is to go IB. 

For those that have a hatchback or an SUV, that want to keep trunk space, yet still want to have good response down to 20Hz, would you still recommend a high efficiency subwoofer (above 91dB 1w/1m)? 

Kelvin


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## subwoofery (Nov 9, 2008)

squeak9798 said:


> This is by far the worst generalization I've read in a long, long time.


Agreed... I've heard Image Dynamics demo car 4 years ago with horns, ID X69 and a pair of IDmax 12s each on its own Q1200.1 @ 1 ohm - and that system was an all out SQ system that got loud when needed. 
Dynamics dynamics dynamics FTW  

Kelvin


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## BuickGN (May 29, 2009)

subwoofery said:


> You have trunk - easiest way to go around "Hoffman's Iron Law", while keeping the trunk space to a maximum, is to go IB.
> 
> For those that have a hatchback or an SUV, that want to keep trunk space, yet still want to have good response down to 20Hz, would you still recommend a high efficiency subwoofer (above 91dB 1w/1m)?
> 
> Kelvin


I would go ported if I couldn't go IB. Most cars are trunk cars. I wish there were more efficient subs for IB out there. Right now its hard to find efficient subs for when you have a ton of space. I would have expected more IB setups with efficient subs on a Diy website especially with all of the sealed boxes in trunk cars.

In a SUV, sure, go with an efficient sub setup in a larger box if theres space. IB has been done successfully in a hatch. I know what you're saying, I know Hoffmans law, but for ME I would take efficiency any day. I believe IB has the least number of compromises.


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## sqshoestring (Jun 19, 2007)

I never investigated enough the reasons why a less efficient sub will be louder (in the model even) than a more efficient sub (which is usually efficient someplace above sub frequencies). But this is not always the case. The really efficient sub usually is harder to tune because many of them like to play high, really like to play high. There is some KEF sub some here like that is like a giant midbass in FR, though at sub frequencies it does still model a little higher in spl. At 50+Hz it is WAY higher spl.

IB is great when you actually need your trunk to use as a trunk and hold stuff, and you want some healthy low bass 35Hz and under. The low power is not a big deal these days since power is everywhere, but it is nice to use a smaller footprint amp and not have dimming issues or 1ga cable to run.


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## cleansoundz (May 14, 2008)

Subscribed.


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## subwoofery (Nov 9, 2008)

BuickGN said:


> I would go ported if I couldn't go IB. Most cars are trunk cars. I wish there were more efficient subs for IB out there. Right now its hard to find efficient subs for when you have a ton of space. I would have expected more IB setups with efficient subs on a Diy website especially with all of the sealed boxes in trunk cars.
> 
> In a SUV, sure, go with an efficient sub setup in a larger box if theres space. IB has been done successfully in a hatch. I know what you're saying, I know Hoffmans law, but for ME I would take efficiency any day. _I believe IB has the least number of compromises._


Most cars in the US are trunk cars, in Europe and here (in Tahiti), most cars are hatchbacks or station wagons... I know some have used IB in hatchback successfully but the work needed to seal the front and the rear waves are way too much hassle - much more work than a car with a separate trunk. 

In car audio, it's all about compromise and I do think that high efficiency is not a good idea if you want to keep the enclosure small <-- look at old school pics with huge box and only 300 watts... Ported enclosure only sounded good to me if they were tuned below 28Hz ; else they don't produce those distinct notes and sound just like a louder sealed enclosure and usually have a peak around 45Hz that need addressing with a PEQ. 

Don't need to keep your spare tire? Yes, you can go with an efficient subwoofer but what's the compromise here? When I have a flat tire, it cost me $160 to tow my car  

Do agree with your last sentence though. 

Kelvin


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## BuickGN (May 29, 2009)

European cars are of no concern to me. 

As I said "*I* would rather have a light cone, soft suspension and a high efficiency rating. My subs feel like they forgot the spider, the suspension is so soft but they require so little power to get loud. Screw power, give me sensitivity."

Notice the word "I". In MY trunk car I would rather have an efficient subwoofer. So for at least the second time in this thread, " I know Hoffmans law, but for ME I would take efficiency any day. I believe IB has the least number of compromises."

I can't imagine going with anything else unless my goals changed. Right now I have efficiency, space savings, decent SPL, and a very flat response that digs deep. It's perfect for MY car. I could have gone with an inefficient sub in a small sealed box but that would make no sense.


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## subwoofery (Nov 9, 2008)

BuickGN said:


> European cars are of no concern to me.
> ^ that I know, but I asked a simple question for those that have a hatchback. I know this is a US forum but there are a lot of overseas posters here too... For example, here's the US version of the 135i and here you have the Europeen version of the 135i
> 
> As I said "*I* would rather have a light cone, soft suspension and a high efficiency rating. My subs feel like they forgot the spider, the suspension is so soft but they require so little power to get loud. Screw power, give me sensitivity."
> ...


Not here to prove you wrong, just wanted to know why you're so hung up on efficiency for a subwoofer - if you like efficiency so much, you should try Pro Audio drivers on your front stage then  
I know why some use Pro Audio drivers in a front stage - but for a substage though, other than IB, I believe efficiency is not needed - unless you really don't want to use a big amp but don't care for a huge box in a car. 

Kelvin


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## BuickGN (May 29, 2009)

If Dyn comes out with a pro audio set I will probably buy them. Its about compromises. I love the realism of Dyns, the SQ comes before the sensitivity. I think the midbass is overworked on most systems hence the 9" midbass. A pro audio 10 would have trouble on the low end compared to an "auto" 6.5". The sub usually draws the most power so going with something efficient gets me closer to my goal of a decently loud system on the stock charging system with no ill effects such as dimming.


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## thehatedguy (May 4, 2007)

Most of the pro speakers want to be in a ported enclosure...or really small sealed. The old IDW 15s wanted about 1-1.25 cubes sealed and about 2-2.5 ported. Not super small, but still pretty well. You would want 2 of those drivers since they had about 5mm of excursion. Modern pro 15s and 18s have bumped the excursion up 3x that, so you could probably use one in a smaller sealed enclosure and be ok given some boost from cabin gain.

And a lot of it depends on how much of that 20 and down you want to feel. If you are going for home theatre special effects...then you may not have the room in the car to do it "right." But for 98% of music out there, you might would be fine.

I haven't "run the numbers" to see if any of that is true, but just a gut feeling.



subwoofery said:


> You have trunk - easiest way to go around "Hoffman's Iron Law", while keeping the trunk space to a maximum, is to go IB.
> 
> For those that have a hatchback or an SUV, that want to keep trunk space, yet still want to have good response down to 20Hz, would you still recommend a high efficiency subwoofer (above 91dB 1w/1m)?
> 
> Kelvin


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## AKheathen (Sep 10, 2011)

referencing "light cone, soft suspension and high sensitivity"-
think about what is making the high sensitivity. it actually is the low mass and soft suspension. this is how old school subs primarily were built. deep bass wasn't really big. as mentioned, you get an effect of a really large mid-bass. once again, look at what is determining the sensitivity. if you start with a good bl "force factor", and add in a light cone and soft suspension, there is not much work needing to be done to make it move, so it is sensitive to less power. at higher frequencies, the cone is moving less air, so the "airspring" force on the cone is less. simply, you could just say louder. when you get into lower frequencies, the cone is moving in one direction and back the other for longer periods of time. in order to do so with the same 'excitement" of the air, requires much more power, and less mass means it is primarily in the electric force to do said work. to make matters worse, the more it travels, the weaker the field from the motor is in reference to the coil. like moving two magnets apart. less field, not only means less movement/force on the cone, but also less electrical resistance in the wire. if the current is not there to pass in this condition, the voltage will drop. electromagnetic field is real sensitive to voltage change, even 1/10th of a volt makes a big difference. large volume enclosure will help extend the low-end to an extent, but you get, what you get on the front of the driver.

now, let us take the same motor and coil, so the clearances and bl, etc are un-changed. start with a much higher mass cone/assy. where this becomes beneficial, is that once it starts to move one direction, the energy of the mass moving will carry on and have more effect against anything resisting, longer after the field has dropped and/or stopped than a low-mass assy. this translates into greater low-end efficiency and extension. where this has a negative effect is that it takes more field energy to get moving in the first place, and the delay will have the mass fighting the signal being told to move in the opposite direction at higher frequencies. over-all, that makes for lower "1watt" sensitivity, but i don't really mind it not being as loud at 1 watt, given the benefits, especially, if it can have much more potential output, and better sound. next, let us throw a thick, firm surround on it, as well as stiff spiders. not only does stiffer suspension typically give the benefit of improved linear control, but also works like a stiffer spring, meaning, the harder you push one-way, the more violently it will spring back in the opposite direction. the increased spring-rate also helps limit the chances of over-excursion.
so, another thing to consider, is that a 1watt rating does not really depict the overall "sensitivity" and response in the way you seem to imply..


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## BuickGN (May 29, 2009)

AKheathen said:


> referencing "light cone, soft suspension and high sensitivity"-
> think about what is making the high sensitivity. it actually is the low mass and soft suspension. this is how old school subs primarily were built. deep bass wasn't really big. as mentioned, you get an effect of a really large mid-bass. once again, look at what is determining the sensitivity. if you start with a good bl "force factor", and add in a light cone and soft suspension, there is not much work needing to be done to make it move, so it is sensitive to less power. at higher frequencies, the cone is moving less air, so the "airspring" force on the cone is less. simply, you could just say louder. when you get into lower frequencies, the cone is moving in one direction and back the other for longer periods of time. in order to do so with the same 'excitement" of the air, requires much more power, and less mass means it is primarily in the electric force to do said work. to make matters worse, the more it travels, the weaker the field from the motor is in reference to the coil. like moving two magnets apart. less field, not only means less movement/force on the cone, but also less electrical resistance in the wire. if the current is not there to pass in this condition, the voltage will drop. electromagnetic field is real sensitive to voltage change, even 1/10th of a volt makes a big difference. large volume enclosure will help extend the low-end to an extent, but you get, what you get on the front of the driver.
> 
> now, let us take the same motor and coil, so the clearances and bl, etc are un-changed. start with a much higher mass cone/assy. where this becomes beneficial, is that once it starts to move one direction, the energy of the mass moving will carry on and have more effect against anything resisting, longer after the field has dropped and/or stopped than a low-mass assy. this translates into greater low-end efficiency and extension. where this has a negative effect is that it takes more field energy to get moving in the first place, and the delay will have the mass fighting the signal being told to move in the opposite direction at higher frequencies. over-all, that makes for lower "1watt" sensitivity, but i don't really mind it not being as loud at 1 watt, given the benefits, especially, if it can have much more potential output, and better sound. next, let us throw a thick, firm surround on it, as well as stiff spiders. not only does stiffer suspension typically give the benefit of improved linear control, but also works like a stiffer spring, meaning, the harder you push one-way, the more violently it will spring back in the opposite direction. the increased spring-rate also helps limit the chances of over-excursion.
> so, another thing to consider, is that a 1watt rating does not really depict the overall "sensitivity" and response in the way you seem to imply..


Almost all control comes from the motor. As we've seen, the air spring of a sealed box decreases cone control. You say a higher Mms will keep the cone going as the field gets weaker but then suggest a tighter suspension? Do you really want a heavy cone continuing on as Bl weakens? Sounds like a recipe for distortion, with the cone continuing on after the signal stops. It sounds like you're doing the same thing as an air spring, hurting sensitivity and reducing cone control. 

Take my 15s for example. 90.6db 1w/1m (or 91.6 depending on where you get the spec from). Infinite baffle, 152gMms Cms .4mm/N, Bl 10.8Tm and I have to include the ultra low Le of .16. Practically zero EQ required from 20hz to 100hz. So you've got a large airspace, a very light cone for a 15, digs to 20hz effortlessly and efficiently. Which sub in this scenario would you rather have, a heavy coned stiff suspension sub or the AE? Which one is going to be more articulate if you play it up to 80hz?

These very light Mms subs play as low as you want to go and get ridiculously loud off of 250w each. It works and it works very well in the real world.


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## subwoofery (Nov 9, 2008)

thehatedguy said:


> Most of the pro speakers want to be in a ported enclosure...or really small sealed. The old IDW 15s wanted about 1-1.25 cubes sealed and about 2-2.5 ported. Not super small, but still pretty well. You would want 2 of those drivers since they had about 5mm of excursion. Modern pro 15s and 18s have bumped the excursion up 3x that, so you could probably use one in a smaller sealed enclosure and be ok given some boost from cabin gain.
> 
> And a lot of it depends on how much of that 20 and down you want to feel. If you are going for home theatre special effects...then you may not have the room in the car to do it "right." But for 98% of music out there, you might would be fine.
> Agreed, it's true that I have yet to experience a real car system that has the potential to reproduce subsonic notes (below 20Hz) forcefully and effortlessly without sounding overbearing and out of place.
> ...


In a small cabin (mini cooper for eg.), F3 can be higher (50Hz+) since cabin gain starts higher in freqs, I think that an efficient subwoofer is indeed OK in order to reproduce the entire subwoofer range - problem is to fit the enclosure in that small trunk (a DIYer did install a 15" Alpine in his Mini )
In an SUV, where cabin gain happens much lower (40Hz and below), I'm not sure an efficient driver would work unless you use a huge box to bring down the F3 to a resonnable point...
^ talking about sealed box only here

Good point Jason :thumbsup:

Kelvin


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## subwoofery (Nov 9, 2008)

BuickGN said:


> If Dyn comes out with a pro audio set I will probably buy them. Its about compromises. I love the realism of Dyns, the SQ comes before the sensitivity. I think the midbass is overworked on most systems hence the 9" midbass. A pro audio 10 would have trouble on the low end compared to an "auto" 6.5". The sub usually draws the most power so going with something efficient gets me closer to my goal of a decently loud system on the stock charging system with no ill effects such as dimming.


If Dyn comes out with a pro audio, I too would love to hear it  Not sure I'd buy them coz those would really cost a lot of money if they were @ Esotar2 prices... 
Don't know what you mean by a Pro Audio 10" would have more trouble than an Auto 6.5" on the low end... Just need to buy one with the right specs  
Here's an example with 2 Pro-Audio drivers VS 2 Dyns that you used: 
Faital Pro 10FE200 
Beyma 10BR60 








With 150 watts and 3cuft (to mimic IB in a door), here's the Xover point before reaching Xmax: 
MW182 80Hz @ 24dB/oct slope 
Esotar2 650 @ 100Hz 24dB/oct slope 
Beyma 10BR60 @ 50Hz 24dB/oct slope 
Faital Pro 10FE200 @ 100Hz 24dB/oct slope 
Only looked @ the Qts (above 0.4), I'm sure there's better Pro Audio 10 but you get the idea 

I did run 1800 watts of A/B class on a stock 90A alternator with no light dimming when going up a hill with a 4 cylinder car  So any new car should have no problem with that kind of power if the install is good enough 

Kelvin


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## t3sn4f2 (Jan 3, 2007)

subwoofery said:


> If Dyn comes out with a pro audio, I too would love to hear it  Not sure I'd buy them coz those would really cost a lot of money if they were @ Esotar2 prices...
> Don't know what you mean by a Pro Audio 10" would have more trouble than an Auto 6.5" on the low end... Just need to buy one with the right specs
> Here's an example with 2 Pro-Audio drivers VS 2 Dyns that you used:
> Faital Pro 10FE200
> ...


That's easy, running down hill would be harder on the electrical system.


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## AKheathen (Sep 10, 2011)

at 250w, are you putting in ear protection and trying to breathe @30hz? i would have to see what it can really do, without cone distortion, or even failure. i am sure you could get much better output and control with pure class a, but i believe i.b. is severely limited to a peak. plus, i would worry about opening a window, or door at high volume, loosing cabbin pressure or un-loading the driver in any way. what i am saying, is that the motor os not where most of the control comes from, unless you are actually keeping the field live. also, that a stiffer suspension creates a more "live" reaction. i know where you are coming from, and yes, you can get some real good results, but you will always reach limitations far before other higher powered setups. trying to get more out of light, efficient drivers usually leads to cone destruction. i've split cones in half, and even ripped them right apart radially just below the dustcaps. so, basically, to retain the same sq and more spl, you just need to adapt.


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## BuickGN (May 29, 2009)

AKheathen said:


> at 250w, are you putting in ear protection and trying to breathe @30hz? i would have to see what it can really do, without cone distortion, or even failure. i am sure you could get much better output and control with pure class a, but i believe i.b. is severely limited to a peak. plus, i would worry about opening a window, or door at high volume, loosing cabbin pressure or un-loading the driver in any way. what i am saying, is that the motor os not where most of the control comes from, unless you are actually keeping the field live. also, that a stiffer suspension creates a more "live" reaction. i know where you are coming from, and yes, you can get some real good results, but you will always reach limitations far before other higher powered setups. trying to get more out of light, efficient drivers usually leads to cone destruction. i've split cones in half, and even ripped them right apart radially just below the dustcaps. so, basically, to retain the same sq and more spl, you just need to adapt.


Doors/trunk open or shut makes no difference. Well, very little difference, not the kind of difference that would cause them to double excursion and hurt themselves.

I would never run a pure class A, and especially not on subs. 

Not sure what you mean by IB is severely limited to a peak.

The motor IS where most of the control comes from, pretty sure that's not debatable. The air spring reduces cone control. I think you're confusing cone control with limiting efficiency.

Trying to get the most output out of a light cone in a small sealed or ported enclosure might lead to cone destruction but it's doubful that will ever be the case in IB. Mine have been pushed past xmax several times before, no problems. At one time they had a 1,300w amp on them.

IB has the same output potential as sealed but with less power required so it's no more output limited than sealed. Limited compared to ported, sure.

They have 825cm^2 of cone area, 19mm xmax, 25mm xmech. They will be louder than a sub with less displacement, quieter than a sub with more displacement sealed or IB. Displacement is pretty average, maybe slightly above average for a 15, the great thing about this setup is the power required to hit xmax.


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## BuickGN (May 29, 2009)

subwoofery said:


> If Dyn comes out with a pro audio, I too would love to hear it  Not sure I'd buy them coz those would really cost a lot of money if they were @ Esotar2 prices...
> Don't know what you mean by a Pro Audio 10" would have more trouble than an Auto 6.5" on the low end... Just need to buy one with the right specs
> Here's an example with 2 Pro-Audio drivers VS 2 Dyns that you used:
> Faital Pro 10FE200
> ...


The Beyma can barely be considered "pro audio". FS of 45hz, 30m peak to peak xmech, a VERY low for pro audio 91db efficiency, give me a break. I see what you're doing though, attempting to find a driver to suit your argument. How about I pick out the pro audio 10" and the car audio 6.5". :laugh:

The Faital hits xmech at 10mm peak to peak (1mm more than it's xmax lol) vs Dyn's xmech at 26mm. Run the 650 to within 1mm from xmech and the low end is pretty similar. Quite the difference in the real world where it's likely you're going to exceed xmax at some point. Dyn has been shown to be truthful in their xmax ratings, I would have to see one of these klippeled before I believe it. In fact, they state voice coil overhang. That figure will likely drop on the klippel. We can ignore the sheer size of these "pro audio" drivers for now. I went through that site and found plenty 10" drivers that might have a chance of fitting in a car but they were more normal Fs=50-60hz 2-3mm xmax, and 95db+ efficiency.

Alternator output does not matter as much as charging system headroom. My GN with it's 120a altenator has a TON more headroom than my TL with it's 130a alternator. One car has just a couple systems to run. One leaves very little headroom from the factory. Going uphill is great, try the same thing at idle.What does the number of cylinders have to do with the charging system other than the fact the engine is likely at a higher rpm while going uphill. Take an old POS carbureted car in the daytime and the alternator is basically running the ignition system with about 1-2a draw. Add some lights at night. It's easy to see that there's a huge difference between that and a modern car that can draw 80a or more idle in the day with fans, ECU, ignition, fuel injection, fuel pump, navi system, instrumentation, transmission solenoids, with no auxiliary systems running. Add in seat heaters, rear window defoggers, side mirror heaters, steering wheel heaters, headlights, fog lights, active cruise radar. Intermittent items such as power windows, seats, ABS, windshield wipers, backup sensors. That's off the top of my head, I'm sure I missed a TON of auxiliary systems. I got headlight dimming with a 1,000w a/b amp full tilt in the TL at idle with the factory 130a alternator.

Back to my original statement before you completely twisted it as you're getting pretty good at lately, I chose a highly efficient sub setup because subs usually draw the most power. I've considered in a different car using AE midbass/mids. Not pro-audio but efficiency is just as good. I choose Dyn because I like the sound and SQ comes first. I got lucky that AE happens to make great sounding efficient subs. If I had to choose between SQ and efficiency it would be SQ. This stuff is all about compromises. 

Let's forget that my original statement was this: "A pro audio 10 would have trouble on the low end compared to an "auto" 6.5"

Your version of it is this: "Don't know what you mean by a Pro Audio 10" would have *more* trouble than an Auto 6.5" on the low end"

That one word you added slightly changes the meaning, don't you think?


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## chad (Jun 30, 2005)

Seems some here are throwing around efficiency and sensitivity as if they were synonymous....


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## subwoofery (Nov 9, 2008)

From the Klippel site, their Xmax figure is distortion threshold d=10% (d_3_ (motor), d_t_ (suspension) or d_2_ (inductance))

Not sure why you're talking about Xmech, shouldn't we talk about Xmax (rating made by the manufacturer?) - what makes it good in going within 1mm of Xmech and get something like 20% or 30% or even more distortion @ that point? 

I have a few Voice Coil mag klippel test for Pro Audio drivers but none for a 10" driver (guess Dick doesn't like those lol) - so I won't take the xmax figure of the Dyn Esotar2 650 that Erin got during his Klippel test... 

Don't see why the Beyma 10BR60 can't be considered a Pro Audio driver - it's not a super crazy high efficiency driver like some drivers on this website, I'll give you that, but it is still a Pro Audio driver no matter what you say... It's reference efficiency is much higher than the Dyn MW182 you're using (0.2518% VS 0.6718% or 0.75% if you take the figure from usspeaker) Rejecting it coz you don't like "that" particular driver?  
Not to worry, found a few more drivers but have only selected 2 - took me some time to model them all : 
Beyma 10MW/ND 
Ciare NDC10-2.5 
Please note the sensitivity and the reference sensitivity is much higher than the Beyma modelled first. 








Same as before, 150 watts in 3cuft - Xover set so that Xmax stays below max. 

Just for fun, I took the Xmech figure for each driver, the Esotar2 650 isn't louder than any of the 2 Pro Audio drivers... The MW182 matches the SPL of the other Pro Audio drivers between 45Hz and 60Hz but loses below and above that.

It's not the first time I see somebody talk about Xmech when they lost the argument with Xmax... 

Nothing against you, just that I like the discussion we have here  I'm also learning here and like arguing in order to learn some more... 

Kelvin


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## BuickGN (May 29, 2009)

subwoofery said:


> From the Klippel site, their Xmax figure is distortion threshold d=10% (d_3_ (motor), d_t_ (suspension) or d_2_ (inductance))
> 
> Not sure why you're talking about Xmech, shouldn't we talk about Xmax (rating made by the manufacturer?) - what makes it good in going within 1mm of Xmech and get something like 20% or 30% or even more distortion @ that point?
> 
> ...


No hard feelings but I don't like the fact that you take the best pro audio drivers you can find with the lowest sensitivity I've ever seen on a pro audio driver and compare it. I don't like that you change my words so that you can create an argument to fit your needs and drag me into it. You come across as an ass. Just as when you try and teach me Hoffman's law every single time efficiency is brought up after I clearly state that *I* prefer a high efficiency sub in *MY* trunk car. Or change the subject to European cars to suit your needs. I could care less what people with hatchbacks do. We can argue all day but I'm just before saying **** you if you continue to put words in my mouth or change my words. I know I'm not the first person to have this problem with you, I've watched it happen with others in the past.

I'll model a few for you tomorrow, the best of the car audio drivers against the worst of the pro audio drivers and we can go round and round.


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## chad (Jun 30, 2005)

Those sensitivity numbers are becoming typical now that the line array element has shrunk and now they have to get some sensible LF out of a smaller driver. Remember that in that situation element spacing is VERY important. So yeah, it's a real pro "midbass" in that format whereas a few years ago it would have been a midrange. And more sensitive. 

Sent from my Sony Tablet S using Tapatalk 2


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## BuickGN (May 29, 2009)

chad said:


> Those sensitivity numbers are becoming typical now that the line array element has shrunk and now they have to get some sensible LF out of a smaller driver. Remember that in that situation element spacing is VERY important. So yeah, it's a real pro "midbass" in that format whereas a few years ago it would have been a midrange. And more sensitive.
> 
> Sent from my Sony Tablet S using Tapatalk 2


What's the reason behind the shrinking line arrays?


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## subwoofery (Nov 9, 2008)

BuickGN said:


> No hard feelings but I don't like the fact that you take the best pro audio drivers you can find with the lowest sensitivity I've ever seen on a pro audio driver and compare it. I don't like that you change my words so that you can create an argument to fit your needs and drag me into it. You come across as an ass. Just as when you try and teach me Hoffman's law every single time efficiency is brought up after I clearly state that *I* prefer a high efficiency sub in *MY* trunk car. Or change the subject to European cars to suit your needs. I could care less what people with hatchbacks do. We can argue all day but I'm just before saying **** you if you continue to put words in my mouth or change my words. I know I'm not the first person to have this problem with you, I've watched it happen with others in the past.
> 
> I'll model a few for you tomorrow, the best of the car audio drivers against the worst of the pro audio drivers and we can go round and round.


Waaah  

Comparing drivers to find a better alternative to some other drivers is the spirit of DIYMA - well maybe used to be. 
The first Beyma driver that I modelled was a simple run of the mill one - had to choose a driver with a Qts (higher than 0.4) closer to Dynaudio in order to make the comparison @ least fair. The first Beyma driver cost around $200 for the pair. The Faital is even cheaper @ $120 for the pair
Since you discarded the choice I made, I then went back to the website and simulated more drivers - second graph... Those were more high-end than the ones in the first graphs. And I feel those were a better comparison since Dynaudio is a high-end manufacturer - so don't really understand why you want to prove me wrong by doing a simulation with the best of car audio and the worse of pro audio :worried:

I actually wanted other posters to jump in and argue too - not just you. If I'm wrong, then I'm wrong and would love to have somewhat prove me then explain why I'm wrong... 

It's human nature to protect something that we love but it's OK to accept others point of view too... And just to make sure, I've never said anything bad about Dynaudio and you can check on the web for confirmation. Did not even include price in this discussion coz it wasn't part of my argument. 
And please remember you were the one comparing a 10" pro to a 6.5" car driver. Seeing that, I had to see if that was true, opened WinISD and checked...

Guess I'm done here then, have a good one. 

Kelvin 

Edit: wanted to thank you for your contribution to the forum, thanks to you I am very interested in trying a 10" driver as a midbass like you did the MW182


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## BuickGN (May 29, 2009)

You can say whatever you want about Dyn, its an inanimate object, who cares. I don't love them, but I do like the way they sound. There you go again assuming. It's the constant harassment, twisting my words to create an argument that annoys me. Ive learned a couple things but I'm too annoyed to discuss.


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## trojan fan (Nov 4, 2007)

BuickGN said:


> I know I'm not the first person to have this problem with you, I've watched it happen with others in the past..


BuickGN.

I know exactly what you are talking about....He's pulled the same BS on me before

He has a tendency not to give up until he can prove someone is wrong

Do the numbers ever lie


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## subwoofery (Nov 9, 2008)

trojan fan said:


> BuickGN.
> 
> I know exactly what you are talking about....He's pulled the same BS on me before
> 
> ...


Yep... Did debate and argue with George (CVJoint), Erin (Bikinpunk) too and yet we still get along well... This is a community, sometimes we get along, sometimes we argue. 
I always try to provide either infos, proofs or data to my arguments, isn't that how people argue in real life? 

I'm not gonna argue with you again, am just gonna let people decide if I really was a jerk - and if I was please tell me  I won't get mad : 
http://www.diymobileaudio.com/forum/technical-advanced-car-audio-discussion/121064-search-bass-car-not-much-space-2.html 

Kelvin


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## chad (Jun 30, 2005)

BuickGN said:


> What's the reason behind the shrinking line arrays?


Smaller venues can benefit from the advantages but yet not hang a full size Vertec, Martin, etc. 

Some genres of music and speech don't require that much grip on the air or sheer volume so you still get directivity control out of a long articulated array but it's not so ungodly huge that it's a PITA to hang (weight for rigging motors) and is less expensive in trucking to tour with.

Same reason I don't commute solo in a suburban, application


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## thehatedguy (May 4, 2007)

I thought Kelvin was pretty correct...

but that's just me.

And Chad's point about sensitivity and efficiency getting mixed up was of course spot on too.


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## trojan fan (Nov 4, 2007)

subwoofery said:


> I'm not gonna argue with you again,
> 
> Kelvin



....Thank you ....Kelvin!!!!


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## BuickGN (May 29, 2009)

subwoofery said:


> Yep... Did debate and argue with George (CVJoint), Erin (Bikinpunk) too and yet we still get along well... This is a community, sometimes we get along, sometimes we argue.
> I always try to provide either infos, proofs or data to my arguments, isn't that how people argue in real life?
> 
> I'm not gonna argue with you again, am just gonna let people decide if I really was a jerk - and if I was please tell me  I won't get mad :
> ...



Again, I learned something new but with the way you come across, acting as if I said no pro audio speaker can match a car audio speaker so that you can have an argument with yourself is retarded. So just as pointless yet just as meaningful I'm going to model the worst of the pro audio drivers against the best of the car audio drivers exactly as you have and we'll keep this thing going until the mods shut it down if ever.

To the guys saying he's right, yes he is but I'm not wrong either. He changed the subject and acts as if it's my subject for the sake of bolstering his ego.


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## trojan fan (Nov 4, 2007)

:snacks:


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## thehatedguy (May 4, 2007)

No one said you were wrong. You are the one who witt seems who wanted to argue.


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## BuickGN (May 29, 2009)

thehatedguy said:


> No one said you were wrong. You are the one who witt seems who wanted to argue.


Did we read the same thread??? I ignore the dude most of the time but it's gotten pretty old lately. From your past comments I'm not too surprised you believe this.


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## bassfromspace (Jun 28, 2016)

I'm gonna hang out with my port.


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## chad (Jun 30, 2005)

bassfromspace said:


> I'm gonna hang out with my port.


she's gonna kick your ass for saying that.


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## bassfromspace (Jun 28, 2016)

chad said:


> she's gonna kick your ass for saying that.


I'm not standing for it tonight. I gotta plan.


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## BuickGN (May 29, 2009)

bassfromspace said:


> I'm gonna hang out with my port.


Lol. When I got my IB15s I put one under the covers on her side of the bed and one on her pillow, to take her place. She was not amused.


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## ChrisB (Jul 3, 2008)

F*ck speaker sensitivity because POWER is where it is at!

I'm waiting on a phone call, so feel free to argue amongst yourselves now.:laugh:


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## thehatedguy (May 4, 2007)

I cleaned it up...sorry for taking it to the gutter.


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## thehatedguy (May 4, 2007)

Buick, I cleaned up both of our messes...keep on and you will get some infractions.


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