Fred Maxwell

This is not true, in any sense. I am the moderator for the Exact Audio Copy group on Yahoo. I am an engineer. I design, upgrade, and build high-end audio equipment.

Ripping a CD does not, in any way, change the content. It is a bit-for-bit copy. Converting it to an MP3, AAC, FLAC, or other format does not reduce the bass in any way. In fact, even on lossy formats, there is no high-pass filtering that reduces or eliminates the amount of bass.

I could show you the results on a spectrum analyzer if you doubt me.

Darth Kinetic

Then whats the point of LossLess file rips?

Fred Maxwell

That's untrue -- and I'm an engineer, not just a user of audio equipment. More often than not, poor subwoofer performance is caused by trying to put too large of a cone into too small of a cabinet. It's a Thiele and Small parameters thing.

Paradigm produces the Reference Signature SUB 2. It costs $9,000, has a 4,500 watt amp (3,000 watt if you don't have a 240 volt service run for it), weighs 230 pounds, and uses 10" drivers. Its minus 3dB point is 12 hertz. If 15" drivers could have worked better in this high-end subwoofer, they would have been used.

warped ideas

I'm glad to hear your an engineer...twice. In my ripping and pirating as a youngster the first notable difference for me was a loss in Bass. I'm not an engineer or an audiophile but can speak from my own past that what seemed to be lost the most was my bass. Maybe it was my methods or equipment that caused this. I don't know and really don't care. I just buy the music nowadays and it always seems to sound a TON better. (quality)

So, back on topic, what can we use thats already in our vehicles to give us higher dB from our stock Bose system?(quantity) Now, please enlighten me/us oh wise engineer.

Darth Kinetic

Yes please.

Fred Maxwell

Only one of those replies was to you -- I had no way of knowing that you would also read the other one.

I also don't know how you could think that was boasting. Electrical engineering is just a regular, middle-class job. I only mentioned it because it was relevant to the topic at hand -- had I been commenting on trees and was an arborist, I'd have mentioned that.

Call Crutchfield. Oh, wait; their website says their Advisors are "experts" and each Advisor's qualifications are listed. That might offend you. Guess you're on your own.

Fred Maxwell

I've got a G37X sedan and I'm looking for something non-intrusive -- I don't want to turn my whole trunk into a home for subwoofer enclosures. I'm looking for high-quality, tight bass, not boomy, exaggerated bass.

I am thinking of replacing the stock Bose subwoofer on the package shelf. I will look at something like a JL Audio subwoofer. Given how flimsy the sheet metal is, I might reinforce it, or, at least, put a Dynamat equivalent onto it to avoid ringing and rattles.

In all likelihood, I would need to create an enclosure as the size of the trunk makes it like an infinite baffle and most subs are designed for an acoustic suspension or ported enclosure. Mount them in an infinite baffle, and the bass gets loose and sloppy and the cone travels too far. I might create a shallow fiberglass enclosure that just sits below the package shelf and stretches across it to get the proper volume for the subwoofer.

I'd also install a higher quality, higher power amp. It's my understanding that the Bose amp employs EQ, partially to compensate for driver shortcomings. So it's unlikely to match up well to a higher-quality aftermarket subwoofer.

I realize that's all rather vague, but I don't want to steer anyone wrong when I'm just in the research stage of this myself.

Darth Kinetic

Oh yeah! You have arrived to where I proposed we start. Replace the amp to the deck subs, which btw in the Coupe are two 6x9s..replace the 6x9s with high quality 2way 6x9s or 8"s that can thump on their own, perhaps with a cross over to keep the highs out as the side panel 5"s will cover.

perhaps enclose these if possibke to allow for a tighter response.

Then add a dedicated Subwoofer amped and crossed over.

This only leaves the thought of making the component setup in the doors better some how... as in replace the 10s with a better 10 or other?; place that amp as well and use a cross over for the subs mids and tweets?;
Or ???

Simply adding a 10" sub to the mix has been the shortest answer but not Really a solution

Btw I appreciate your acknowledgment of being an engineer. It qualifies your input.
Toot away.

Fred Maxwell

I think that 8", or even 6", round subwoofers are a better bet. There aren't a lot of 6x9 speakers that are designed for the kind of cone excursion that you need for subwoofers (given their cone area). The Bose speakers in there have wimpy magnet structures and the cone looks like paper(!). I'm only going by pictures.

I think that the enclosure(s) to fit behind them presents the biggest challenge. I've not found subs that you can just drop into an open trunk and get good sound in the car. Almost all of them have ultra-compliant surrounds and rely on the "spring" (acoustic suspension) from the air behind them to control cone motion.

I really like deep, tight, accurate bass, but not boomy bass. In the 1990s, I wrote an editorial in Car Audio & Electronics (defunct, now, I believe) entitled "Say No To Boom." Their editor said that it generated more user feedback, both positive and negative (fortunately, more of the former than the latter), than anything that they'd ever published, so I know it's a subject that people are passionate about.

Definitely. Go with an electronic crossover or an amp that has an adjustable low-pass filter. I'd stay away from inductors and caps at the speaker itself.

Aren't the replacements for the 6x9" speakers intended to be dedicated subwoofers?

Honestly, I have no idea why Bose went with such large drivers in the doors. But I would change one thing at a time, starting with the components that Bose intended to function as pseudo-subwoofers.

I would not add anything yet. First I'd replace things. Take out sub-par, non-optimal components and install higher-quality, better spec components. Too often, people take a shotgun approach, replacing almost everything, spending massive amounts of money and time, only to end up with a system that's too complex for them to tune by ear.

Thanks. That's all I ever intended it to do.

Darth Kinetic

I thnk the intent from Bose was the 6x9s to be fill, not woofers, let alone SUBwoofers...

I agree with you , IF I can get Tight bass out of the Rear Deck, thenI dont NEED a dedicated Subwoofer
BUT as it has been pointed out here 6s or 6s are not going to do that as well as a 10 or a 12.
SO,
I suppose we could throw in a 2 or 3 way pair of 6" to act as FILL

and then add a true SUB to the trunk. and stop tring to get bass out of sub par, underpowered, woofers

I was 'hoping" that a free air 6 or 8" pair in the deck would FILL well musically and "possibly" add some high range bass and then dedicate a real Subwoofer to the mix.
lets make the rear setup a tue component like the front of the cars, Seperate Highs to the Side wall 5", mids to a pair of 6s or 8"s and then a true LOW Subwoofer added on....

then clean up the Front as describe above.. I think this could work...
thougths?

Darth Kinetic

btw Fred, I think you should take Warp's responses Tongue in Cheek.
I know from his other replies that he likes to add humor, and some sarcasm to his banter, but I feel positive he is as interested in a solution as we are.

just my .02

warped ideas

Mature of you.^^^ See how far that attitude takes you when your **** breaks down and you start posting up questions trying to figure out how to fix it. You'll be real popular 'round here I have no doubts.

Darth Kinetic

Ok Warped that's not going to help. Especially after I just tried to get him ignore your snark and sarcasm.
How are we to discuss real matters when you guys start pissin on each other?

warped ideas

Hey.... He started it! I'm out...

Fred Maxwell

According to the parts diagram I was able to find, they are described as "Rear woofer LH" and "Rear woofer RH." Lacking even a whizzer cone, much less a tweeter, they'd be hard-pressed to do much above low midrange. So I think replacing these with decent subs powered by a good amp with a crossover may be a very good starting point.

A pair of high-end 6" subs in a proper enclosure will blow away a 10-12" sub in an incorrectly sized enclosure. But you might be able to use 8" subs with only minor trimming/adapting.

You mention free air speakers later on. Free air subs are reasonable to keep things simple, and they require a lot less power. But they tend to be a bit loose and sloppy and limited in maximum SPL. In order for them to work right, you need to create a stiff baffle on which to mount them -- something a lot stiffer than stamped sheet metal. It's to keep the back-wave that goes into the trunk from leaking back into the passenger compartment and canceling out the bass. There's also the rattle/buzz issue. When you start pumping a lot of bass back-wave energy into a closed trunk, rattles and buzzes are common and sometimes hard to track down without a signal generator to hit and hold the offending frequencies.

Once you start getting into midrange and higher frequencies, the directionality, and phase cancellation (due to the speakers being varying distances from your ears), becomes an issue. I tend to like the majority of the HFs to come from in front of me, as if the stage is in front of me. But everyone has their own preferences.

________________

What kind of response did you expect when you accused me of tooting my own horn and then sarcastically wrote "Now, please enlighten me/us oh wise engineer"? You thought I was going to spend my time composing a helpful reply to you after that?