Home audio drivers vs. car audio drivers

Drew: To those that understand what Fs, Qts and impedane mean, they will understand exactly what you're getting at. For those that are reading this, it probably went right over their heads : )

Speakers are designed very differently as they have very different atmosphere's ( acoustically and environmentally ) to deal with.

Amplifiers are designed very differently as they have a very different power source to deal with.

Having said that, you can get "pretty decent" car audio gear for not that much money. Just like in home audio, you have "pretenders to the throne" who rely on hype, cosmetics and fictitious spec's and then you have "the real deal" type of components that are built and designed around real world operating conditions and environments. Guess which type of product is most likely to be found in the majority of "boom boom" vehicles heading down the road. If you're not sure, just think about how much Pioneer / Sony / Kenwood type stuff you see in home audio as compared to even Parasound, Adcom, NAD, etc.. type gear. This is not to mention the likes of "audio standards" such as ARC, Krell, Pass, etc...

Cheaper junk that promises you the best for the least amount of money is what keeps the economy alive. People buy cheap junk, find out exactly how junky it is and then sell it to buy the next higher level of junk. Without all of the low grade junk and the learning experiences involved, we wouldn't have a "High End" in either home or car audio. It's just too bad we can't to how "junky" the low grade "junk" really is : ) Sean
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PS... Most car audio subwoofers are designed for maximum output at higher frequencies with little concern for extension and / or linearity. This results in more apparent bass, which is why you hear "boom, boom boom" or "thud, thud, thud" rather than musical notes. Then again, most of the recordings that have that "boom, chukka, splash" on them isn't very "musical" to begin with : )

Gunbei: Most car stereo woofers have a high Qms, which results in a big impedance peak at resonance. This is what causes the bloated, indistinct bass that you hear from the "boom / tizz" vehicles. Lower impedances aren't a problem for a good amp, but as you mentioned, damping factor is reduced.

As a side note, damping factor is NOT the ability of the amplifier to control or load into the driver so much as it is the ratio of how much potential there is for the reflected EMF from the driver to modulate / distort the output of the amplifier. This is a very commonly misunderstood spec with even EE's, designers and manufacturers not knowing how to interpret it or what it really means.

The higher the damping factor, the less susceptable the amp is to being affected by the reactance of the speaker. The ability of the amp to efficiently transfer power into the driver / speaker system ( including cabling ) is what will determine how much "control" the amp has. Unfortunately, there is no spec for this that i'm aware of.

Take a look at this link pertaining to impedances, reactance, loading characteristics and power transfer in the AA Speaker Asylum archives. Pay special attention to the exchanges between myself and that of Dan Wiggins of Adire Audio and to a lesser extent the few responses between myself and Bobby Palkovic of Merlin. One of these two guys is a LOT smarter / more experienced than the other, but i'll leave that up to you to figure out which one it is after reading the exchanges there. While punching in T/S parameters into a computer program and then interpreting the data can provide a lot of useful information, it does not make one a knowledgable speaker designer. Sean
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Cdc: "You say Dan Wiggins can't use a vented box that can outperform a sealed box but he shows how he can."

Beat it in what manner? Given optimally tuned designs, a vented box may have greater extension and output, but it will never have the same amount of definition and transient response that a sealed box can achieve. Like i said, quantity vs quality.

"Bobby is lowering bass below tuned freq. which you say increases distortion and he says he found a way around that."

That is what Bobby says. As i mentioned in that thread, NOWHERE in the Stereophile review is distortion measured or quoted.

"Sounds like you don't think either one knows what they are doing / following the laws out physics."

I think that Bobby has a much better idea of what he's doing than Dan. Dan is all about computer designing a product for maximum quantity, not maximum quality. If you doubt this, look at the Adire website and you'll see the "monster" sized woofer with mega-excursion that they are working on. Given that Dan doesn't understand the difference between an amp being able to load into a speaker and what damping factor means, it is pretty obvious that he's letting the computer do his thinking and work for him.

On the other hand, Bobby is about hands-on experience and tweaking for optimized results with minimal trade-offs. He understands what the words "control", "loading" and "damping" mean.

Dan will get you a lot of sound. Bobby will get you good sound.

"To my ears Dunlavy's sounded much less dynamic than Virgo III's or B&W. And B&W publishes distortion under 1% with their vented boxes. Bass is very tight and picks up on the beat (toe tapping)."

Dunlavy's had their own problems, just like any other mass-produced speaker. On top of that, most people aren't used to listening to "tight" bass with minimal ringing. Facts is facts, personal preferences are something all-together different.

Try taking a look at this >website. Click on "tech notes" and then "bass loading" and read that. He basically repeats the same things that i said in that and a few other threads. For sake of clarity, i'm not taking credit or saying anything that hasn't been said and proven to be fact long ago.

If you doubt these facts or just want to delve deeper into the subject and learn for yourself, pick up a copy of Vance Dickason's Loudspeaker design cookbook. As i've mentioned before, I would always encourage one to learn for themselves, both through reading and hands on experience. The more that you know, the less bullshit you'll be forced to unknowingly swallow.

Believe me, i learned the hard way. I used to think that sealed speakers were for idiots when i was younger. Why would anyone want a speaker that didn't play as loud, go as low or took more power to operate? The answer is obvious once you learn how and what to listen for. Like i said before, quality vs quantity. Sean
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