Audio Help UPDATE

Thanks again to those who gave me advice on my audio system last week. Over the weekend, I went back to Paris Audio and they (Jamey) spent some time tuning the system. I was lucky as the shop was quiet and we were able to take an hour or so to play with different crossover adjustments. Bottom line, it now sounds fantastic. Like a completely different system! I know that tuning and eq makes a big difference, but it was amazing to see how someone who really knows what they are doing can get the max out of a system. (In Jamey's words, "that's the difference between [Jamey's] installer with 7 years of experience and [Jamey] who has 20." I think it shoudl have been set right from the beginning, but luckily I'm local and didn't mind spending the time to go back and get it right. Although Paris is expensive, there was no questions asked about opening it up and figuring out how to make it better (obviously, no charge). Although the stereo sounds enormously better, it still needs a sub (as I think all but one of you agreed). I'm going to upgrade the amp - maybe to the Diamond Audio D7 (5 channel with much more power) - and do either a 10" or pair of 5" in the passenger footwell. Anyone have a suggestion as to whether the single larger sub versus the pair of smaller ones will be better?

Glad to hear they got your crossover settings right for you. I could not think of any reason other than that as to why the system would not have sounded good to begin with. If it were my choice... I would go for a single large sub as opposed to several small subs. Try to listen to both and go from there.

Two "fives" with deeper voice coil throw and higher efficiency voice coil magnets and a good tuned enclosure will always yeild better performance than your "average" 10". Don't buy the 10 inch just because it's bigger (is better) and more expensive(??), higher margins to the seller.

"set right from the beginning".... Why? Remember that 9 out of ten folks will never notice the difference, why should the installer/shop put the extra (SKILLED, highly paid) labor, and forego the extra profit margins, unless the buyer comes back and complains. "7 years experience".... Over-qualified technician (demand more pay) for the average upscale automotive audio shop, maybe your experienced guy was part owner.

ER: I went with the 5's in the footwell, as I was told that they'd hit harder and blend better into the music. I didn't really need them to sound 'sub-like' - I just wanted musicality. That said, I still get a pretty whomping amount of bass, and Paris installs a sub-level control in the dash so you can constantly add as much as you want. A 10" driver will drive lower frequencies, but will also have a much slower response so you run the risk of muddying up the low end a bit (and it will need a bigger amp to run as cleanly). But ask Jamey to demo the different systems - he did for me & I've been really happy with the 5's...

I've read that bass response is based on surface area of the subs, so a single 10" (pi*rad*rad = 25pi) would likely be better than two 5" (6.25pi*2 = 12.5pi), although as wwest says the quality of the speakers could make all the difference. I have two 8" subs, like many folks here, and I love it. I probably have "average" speakers, though (MTX Thunder 4500 @ ~$90 each). I went with the recommendations of my installer, which served me well. I'd listen to what the folks at Paris are suggesting, after they understand what type of music you listen to and what type of experience you want.

Thats fantastic ER996! now thats its correctly tweeked, you can safely go on upgrading from there until its sounds just as you want it to. About the pair of 5" vs single 10", it depends on your personal "taste" and the type of music you normally listen to. With the pair of 5"'s you are going to get more of whats known as "TIGHTER" bass, with more kick. But on the other hand with the 10" you are going to get more filling or fullness bass response, and since its going to be in a sealed type enclosure its not going to be "booming" base such as vertex or especially bandpass enclosures (the ones you hear from blocks away), so its still going to be on the tighter side (which is the bass I personally like). And you still get "some" of the similar to the two 5" bass and quick response from the 6" woofers in the doors already. Thats why I would personnally preffer the 10" because its a better compromise more versatile, more complete. 5" speakers are not really subwoofers, and are used as alternate solution for small places where you can't fit the larger subs. The 10" for example, due to the larger cone surface area and greater excursion, is going to maintain bass better than the pair of 5"'s at higher volumes with the high ambient noise associated with driving, thats also important, since one thing is in the shop and another while driving. But bottom line is, both are good solutions but depends of personal preference and since its hard to describe with words, if you have the oportunity to compare, I highly recommend it, though you will notice a great improvement with both. BTW why not behind the seats and not occupy part of the the footwell? It shouldn't be anymore expensive? You have more room there to fit wahtever you like, maybe two 8" subs which would be even better. Let us know how it turns out...

10" vs.... Speakers are nothing more than AIR PUMPS. Or: A 4 cyclinder 3.0 liter engine can deliver just a much Hp/Torque as a 3.0 liter V6. But if the 3 liter 4 cyl has a short stroke in comparison to the V6's long stroke the HP/torque ratios between the two might vary widely. I would think that the task of designing a confined space tuned enclosure for two smaller "air pumps" might very well be a much easier task than of one designed with just one large equal capacity "air pump". Have a look at how most, even upscale, home theatre systems attack this problem.

Good idea... goto a place like Circuit City and compare the sound and output a Bose subwoofer (small speaker and enclosure)to the sound and output of something like a Velodyne or Paradigm subwoofer (larger speaker and enclosure). They both do the job, but turn up the volume and you can see which design falls short. The reason being is that one is more of a compromise approach... you can figure out which one on your own. Talk to the boys at Paris, tell them what you want, the type of music you listen to, and listen to their suggestions. They should have a way for you to compare both types of sub systems. Go with the one setup that pleases your tastes the most... and let us know what you do. In the end, you will be the one listening to it... not wwest, Carlos, or myself . Two eights...

Wwest, do you even know how a CAR stereo sealed enclosure of a 10" sub or two 5" speakers is built? and what the difference is in performance and in sound? Lets try to give ER996 some positive constructive feedback, please.

Carlos, Your really should have figured out by now that yes, I do know what I'm talking about in the audio world, probably moreso in the home or studio environment than in the automotive environment. You just simply cannot make a silk purse from a sow's ear so I haven't wasted much time trying to reach the ultimate in automotive audio performance. Circuit City.... Well, the equipment you want to hear is likely to be there, that's certain. But I'd be willing to bet that if you follow that young inexperienced lowly paid salesman out to his car (the other gender doesn't go "here') he'll be glad to show you his idea of good bass reproduction. But cover your ears first. If you were in the Seattle eastside area I would send you to Definitive Audio or Magnolia HiFi. The prices are steep but you get to work with an well paid and experienced salesperson (the other gender does go "here") . Not too many years ago throughout my home I had a collection of fairly large (heavy, solid, etc.) speaker enclosures, typically with sub-woofer speakers of at least 10 inches. I gave them all away. Now, I admit, I'm quite puzzled. This crowd, Porsche owners, IMMHO, isn't likely to want to bias the reproduction of audio content so radically toward "thumping" bass like those salemen you encounter at Circuit City and such. So just what is going on here? Are we being elitist? Bigger is better? More expensive is better? Now all of those I could readily believe to be sprinkled amongst "our" crowd. But going out and listening for yourself really is a good idea. Now I really don't know how large, or small, the speakers actually are in a compact upscale sub-woofer enclosure. But I do know that if you take a sub-woofer enclosure with a large speaker, deep voice coil throw/travel and high efficiency voice coil magnets and compare it to an upscale sub-woofer system of relative compact size, your ear, or any electronic instrumentation available, spectrum analyzer and/or DB measurements, will not be able to discern the difference. So, now, forget all of this, take your own CD in, listen, really listen, and make your choice, based on what you actually hear, absent any constraining monetary or other "concrete" limitations. Another thought. In general it will be cheaper, overall, to market a sub-woofer with a single large speaker compared to a smaller one one that definitely needs or requires a tuned enclosure. At the very core is that what is in operation here? The smaller sub-woofer with a tuned enclosure clearly would set the standard for more expensive pricing. A sub-woofer with a larger speaker would clearly need less design work and a much simpler enclosure to produce equivalent output. So. Any audio place more interested, or even only slightly biased toward, the bottom line, (who, Me??), would certainly push a 10" sub-woofer for $200, rather than an equal or even better performing compact sub-woofer for that same $200.

What I have figured out is that, not in the car audio, i.e: Diamond and Focal especially are top notch brands in car audio... As it was explained already, its the subwoofers that allow a more faithful reproduction of the original source because they can maintian the lower frequencies that you loose when car is moving do to the ambient noise and higher volume of the stereo. No, in car audio subwoofers systems, a 10" subwoofer enclosure yields better performace in general from than two 5" subwoofer enclosure. No, we are talkning about a sealed enclosure, both are extremly easy to build. The speaker size has nothing to do with it. The shape of the box so it fits in the place of the car you want is more important in designing it. But what matters most is the type of enclosure, in a vented or reflex enclosure you have to calculate the volume of the box needed for the drivers much more precisely and also design the appropriate reflex resonance tubes which requires some calculatios, a bandpass for example is even more complicated because in essence you are designing a vented and a sealed box joined togetehr separated by the drivers membrane, etc. Wwest, I'm trying to understand your posts and I think the problem is that you are trying to apply your home/studio hi-fi knowledge (which I think you do know about) to car audio hi-fi (which I gather from your haven't bothered with), and that is not possible. They are two different worlds, you can take a car audio an put it in your livingroom and will sound miserable and viceversa. As you can see from all the other posters are in agreement with each other except you. I have read posts from you in other subjects and you have been very helpful and made good contributions but not it comes to car audio you should admit it, its not your cup of tea...

Thanks again for those who've responded. My questions seem to generate some friction between Carlos and Wwest on this topic! I'm not chosing sides here, but thanks Carlos for giving the constructive advice. I will let Paris make their (more experienced) suggestions. Because they are so damn expensive, the cost of doing twin 8"s in the rear is too high (almost $2k for the speakers and box/wiring alone). I know I could get this done cheaper elsewhere, but the quality of the work at Paris is so good, and they've done the rest of the system, it's not worth it. I think I'll do the passenger footwell. It'll be twin 5"s, single 8" or single 10". I'll get their opinion and it'll also depend on space and the quality of the speakers of course. Since I have 6" woofers in the doors, I might not go with the twin 5"s. I do like the bass tight, however, not particularly boomy.

Nah, no friction just a little different opinions but Wwest is a nice guy who you can argue with in a maturely and civilized manner as you can see from his responses 2k? Wow, that is really expensive! I think they need a little competition in the area to lower their prices, thats is severily overpriced! but since they did the rest of the system and you know how they work and their great quality, I think you are making the right choice. I would like to know what you liked best, the single 8"-10" or the two 5" box. Hope everything works out well.

$2000 for a sub box with two 8" subs... that is obscene. eek: There is good quality work available out there other than Paris, just check around. Car Audio Innovations can make you a box very similar to mine with two 8" ID subs for $700. Let us know what you think and what you end up with.

Ah, maturity... Carlos, Whay do you think about... I place an order for an 04 C4S with the Bose system. We take factory delivery next spring, drive it for a month in europe, ending up at YOUR place. We then call the factory and say, "Oops, sorry, we wrecked the car and it can't be returned to the factory for shipment to the US until it's repaired". You now have 30 days to install whatever sub-woofer system is your choice, with a hidden switch so it can be readily switched off, all at my expense. When you're satisfied that all is well with the installation I will return, bringing a spectrum analyzer with a current calibration certificate. I will use the spectrum analyzer to find the bass balance point for Bose "only" sound reproduction vs Bose (neutral balance) plus your sub-woofer. We will take 20 test drives, with you driving, of your designation while playing a CD of your choice. You will not know in which position the switch is on any given test drive. If I decide that the bass balance level you have chosen is more in the range of vibratory experiences we will prove that to you using a neutral third party of your choice and the spectrum analyzer. If you pick the correct switch configuration more than 15 or more times out of 20 we will sign the car over to you and go home. So, that's MY offer. What are you willing to give us, how certain of your ear are you, if you fail the test and cannot really detect when the sub-woofer is in use?

Or you can buy the two subs for about $300, and spend a weekend with some tools and about $40 worth of MDF and construct your own. It's your money!

Hmmm, all stereos sound the same in moving cars so ER996 shouldn't bother to test the two boxes since thay will sound the same? Thats funny Wwest, you are willing to go through a lot of trouble, but I'm sorry if I gave you the impression that I really cared if you are convinced or not. My intention was to give ER996 the best honest advice I could and I think ER996 got that from all the rest of the posters as they were all in agreement in their advice, except you. The poster of the thread got what he wanted. Sorry if you still disagree for whatever reason but who cares? There is no reason to keep argueing, is theren Wwest? lets move on BTW install just 10" bandpass to the C4S and throw in a "tweeking CD" and play the low bass freq tracks, guess what happens with the Bose alone vs Bose with the bandpass as you raise the volume to overcome a moving car's ambient noise (I even have one of those boxes in my garage, have you ever heard one?) if you can't tell the different bass response from one type enclosure to the other (nothing to do with vibratory feelings, its the qualities of the sound not quantity) even at your neutral settings then your acustic nerve has to be fried ... that was too easy Wwest.

Thought provoking discussions. I took this issue into our company lunchroom today. ~ twenty employees, three outside consultants, two visiting dignitary's. Three LS400 owners amongst them, one other Porsche besides me (an 88 911), and one CD equipped Prius. Apparently lots of classical CD music listeners. First let me tell you of a memory that our discussion brought back to me. Many years ago, maybe as much as ten, a friend who is something of an engineer asked me a "why not" question about sound reproduction systems. His question was, "given the huge dynamic range of musical content, why hasn't someone invented an automatic volume control to adjust the output during quiet passages vs LOUD ones?" My response at the time was that AVC capability already exists in many form. I just simply didn't get it, as you will soon see. Today in the lunch room one of our senior engineers described the problem very well. Driving along in his LS listening to a quiet passage on a classical music CD, he has the volume adjusted so he can hear the quiet content. Sometimes the content volume goes upward suddenly and dramatically, which of course leads him to be reaching quickly for the volume control, even quicker if his wife is along. Obviously the reverse also happens and you end up missing a good portion of the beginning part of a "low" passage that was preceded by a LOUD one. The obvious answer ( someone out there want to patent this?) is to invisibly "pre-screen" (microprocessor looks "ahead") the up-coming CD content and then automatically adjust the volume (smoothly) accordingly and just a few milliseconds ahead of the content volume change. You wouldn't have the full 120db range remaining, but the low passages would be above the "noise" level and could still be widely differentiated in volume from the LOUD passages. Someone could even develop unique PC CD copying software for CD copies destined to be played only in an automotive environment. Thoughts....???

Carlos - I'm going to repeat my posting from the post that started this follow-up: Ingore wwest (Willard, I think), as he does this a lot, either trying purposely to start problems by espousing silly, unrealistic statements, or he actually believes this dreck because all systems playing AM talk-radio do sound the same through his hearing aids. Think about the statements. Then apply the exact same logic to the car itself. It would mean, of course, that my ex-wife's Ford Explorer is the same ride as my 996, handles as well, goes as fast, and stops as quickly, all because it has 4 tires and a roof. You should know that any vehicle, so long as it has 4 tires and a roof, has the same exact performance characteristics as any other vehicle with 4 tires and a roof. This would be what is known as a syllogism with an attribution error. There are as many differences between audio systems as there are mechanical differences in automobiles, so of course these differences have a tremendous difference in sound quality (both objective and subjective). But wwest seems to ignore all of these facts, and then spouts out some flawed logic which seems clearly placed to stimulate argument. Wwest, as for you, I've seen your audio postings before, and I have to tell you that they come across as very insulting (and, honestly, quite ill-informed). I, amongst others here, find that quality audio is an important characteristic of motoring. It's worth a lot of thought, time, and money to us, and we're looking for a specific result in which the audio experience matches as closely to the driving experience as possible. Having you change the course of topics from constructive, sharing postings to ones where we start defending ridiculous pronunciations is not productive for anybody. Unless of course to those that like to start trouble. Which, of course - unless you truly are hard of hearing - you are. So do me a favor. Until you are prepared to live by your statements by replacing your tires with Sears steel-belted 13" radials and then racing me on Mullholland, please refrain from dirtying up any audio posting with your nonsense. Thank you.

Have I ever, EVER, in any way attacked or denigrated any of you?

ZeeZee. please, look over my idea regarding the need to dynamically compress the audio content to be played, or playing, in an automotive environment through a pre-screening microprocessor and tell me if it does, or doesn't resolve the problem of over-coming the noise inherent in operating an automobile. Doesn't the Porsche audio system already have a system whereby the volume will automatically increase or decrease with speed changes (or is it with external noise?)?

Wwest: I do NOT mean to offend. Please do not take it that way. It's just that every time I see you comment on audio it's based on logic that does not make sense and has a tendency to insult. So I commented as I saw it. Regarding compression, all that would do is limit the quality of the audio experience. I have a system that doesn't need it. It sounds great from low to high, soft to loud, and most everything in between. It puts most home systems to shame, and I can play it as loud as my ears can handle it without much - if any - distortion. Even with the top down, at 75 MPH, I can play some great music and have it sound as good as I (or my passengers) would ever need it to. And - just to set it straight - my stock audio system couldn't make a single good sound at any volume and with the car off and sitting in my garage. Again - I don't mean to offend - but when you question these facts with a blanket set of assumptions that aren't based on anything it has the effect of insulting me, and possibly others, that put as much time into their systems as I have.

Having read, and then re-read, this series of posts about three times now I think I see the point wwest is trying to make. Isn't it true that CD musical content can have a dynamic range of 120db? And isn't it also true that at 120 db the sound level is approaching the level at which permanent hearing damage can occur? I think that's 140db or above slightly. Now I think that I have heard that the typical ambient noise level in an automobile ranges somewhere around 70db (LS400 class?) and above. If all of the above is true, then to "hear" the quiet passages of a CD the speaker volume would need to be above the ambient noise. playing the quiet passages at a 70db volume level would mean the top sound level would then be ranging up to 190db, most definitely damaging to your ears. I don't pretend that the numbers above are factual, most of them are taken from a now vague memory from somewhere in my past. The conclusions should only be treated as surmises or guesses. So anyone is welcome to step here and correct my numbers and conclusions. As a matter of fact I would actually perfer that someone of more exacting knowledge take the time to check these figures and tell me if the conclusions I have stated are valid. "$00.02"

After doing some reseach on the net I came up with the following. CD's do have the capability of content with 120db range. Human hearing pain threshold is at about 120db. Permanent hearing damage begins to occur at about 140db. My conclusion would be that although CDs can carry such a large dynamic range it is unlikely that recording companies would record content at that high level, lawsuits would undoutedly ensue. Some interesting stuff at dynamat.com Shouldn't be taken as gospel since they're trying to sell you their solution. Siemans automotive group is working on an "ANTI-NOISE system to be used within the engine intake plenum. Apparently it would only take about 2 to 3 watts of anti, inverse, content to cancel out intake noise pulses. Begins to sound like dollars spend on creating a quieter automotive listening environment might yeild a better return on your investment than sub-woofer upgrades. But I, for one, will not be giving up the throaty sounds of the 996 intake.

I have the twin 5's in the passenger floor (from Paris). Those are not subs but mid-bass/woofers. If you try to produce <75hz they will blow. Go with the 10 inch (is it one or two?). In my cab, to switch to the 10 (one), I would have to add a seperate amp for the sub (not much room left as it is).

Discussing the improvement and efferct of subwoofer systems on car audio applications is such an obvious concept nowadays that I can't believe its even being discussed, I for one can't find the motivation to discuss such a basic concept. You don't even need a trained ear to "hear" the difference, even factory stereos (which aren't exactly the best example of best car audios) incorporate subwoofers in their set-ups. Unbelievable, its like discussing the effect of aerodinamic aids such as rear wings in car performance to someone who thinks all wings are aesthetical for the fast and furious crowd.

ERR996, I didn't read all the posts but let me give you my opinion on what I have now and had in the past. My old Lexus SC400 had 2 twelve inch JL12W6's, my 996 has 2 eight inch JL8W3's and my 993 has a single ten inch Polk(don't remember specific). The response of the 8's has the tightest quickest response although I am not entirerly happy with the loss of the lows. The 12's were a little sloppier but hit the real lows beautifully and the single 10 fell right in between the two. This is all of course based on different wattages and brand amplifiers but overall I cannot see two 5" subs putting out any frequencies below the midbass region. John

Carlos... The only CONSTANT these days is continuous CHANGE. I don't disagree that in the near past the standard for automotive sound reproduction was to include a good sub-woofer. What I have been trying to point out is that if that "standard" hasn't already changed due to more current technological improvements, then it certainly will be soon. While in the USAF in the late fifties I worked in a TV/radio shop on the side. At least twice having been temperarily laid off from Boeing I fell back on my other career, TV and Radio. So, vacuum tubes to transisters to integrated circuits to Intel Itanium processors (that sound coming from your PC speakers is being reproduced with 1's and 0's). I could name hundred's of "obvious concepts" of yesteryear that have now fallen by the wayside due to modern day technology.

sicaone, I (too) often see two HUGE speakers "laying" on opposite ends of the rear package shelf of a car. I'm quite sure that although the front of the cone is closely exposed, open, to the rear of the cone, there is some low end bandwidth gain. But given the size of the speakers, and surmising the power level needed to drive them, there is just no way that the low end bandwith gain is appropriate to the size of speaker used and the power consumed. But what I'm trying to give you here is just a tiny inking of the sound reproduction efficiencies that can be had by enclosing speakers within an enclosure. Thinking of those speakers just lying there, I would be willing to bet that if these were installed in the most basic enclosure, and operated at the same power level, then the occupants of that car would need to be some 20 feet away to avoid the resultant ear pain. At volumes appropriate to an automotive passenger cabin, open or closed, two deep throw high efficiency magnet 5" speakers in a well designed tuned enclosure will perform as well as two 10" deep throw high efficiency magnet speakers in a well designed tuned enclosure. But if you're in an open air theatre then you might need twenty of the 10" type, or maybe even 50 of the 5" type.

Wwest, I am not an accoustic engineer, I was just explaining what was pleasing to my ear. I totally agree with you that the enclosure is instrumental to the sound emitted. The JL subwoofers that Sloth and I have, however are supposed to be installed in the type of enclosure that we currently have(huge speakers on opposite ends of box). I also had the chance to hear two 6" subs in the same type of configuration(box on shelf) and mine sounded much better. Out of curiosity, what do you do that you know so much about this topic? I am just an audiophile. John

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Like I said Wwest, I don't wqant to seem rude but what you are still questioning is just too basic to go over it with you, and I've reached the conclusion that you obviously don't want to reason either no matter what, so its would be a waste of time, as far as me, I'm only interested in what ER996 finally went with and how it turned out.

Carlos, There are some men you just cant reach... and thats what we got here today, a failure to communicate. I guess we should just get used to wwest/willard piszing all over what we say and think every time the question of how to improve the audio systems in these cars come up. This is the third time that this subject matter has come up that he has said the exact same rubbish. wwest/willlard, People come on here asking b/c they want to know what others have done in their 996, what their experience has been, and what works. You seem to have a decent theoretical knowledge on things, but IMHO your application of it is faulty. You should really try to find a properly built car audio system (not a boom car, please) to listen to some time so you can first hand hear the difference. It is one of those things that if you have never been in one, you could never fully appreciate it. Point aside, you keep missing the basic premice of audio... if it sounds good to your ears then go with it. Right or wrong, that is the bottom line. So if you are happy with your 4th order bandpass enclosure with 5.25" mid-bass drivers, and all the issues associated with... then more power to you. For myself and others, we will take the simpler, larger speaker enclosure with its associated issues... and more power to us.

Sloth, I have to agree with you, and ZeeZee has also warned me about that, thanks. I was a little slow and fell for it initially since I missed those previous threads about the same subject with the same problematic rising up so I only arrived to that conclusion after this thread Oh well now I know, next time I wont be dragged to a senseless and useless side debate that responds only to the obscure interests of one member, and keep to the original poster's questions

BTW here is coule of pics of a two 10" sealed fiberglass/MDF custom enclosure fitted behind the seats, you know, for those that can hear the difference

Carlos/Sloth, Do you get vibrations in your rear window? I initially did but I stuck a piece of weatherproofing strip between the window and healiner and it worked.

That is nice looking work Carlos. I have seen photos of it before, but never the up close photo. No vibrations from the rear windows here. In fact, I am very pleased with the lack of vibrations from the car itself... other than the subs. Time will tell and the amount of bass you push from the speakers can make a big difference. I tend to keep my bass settings relatively low.

Sicaone, Same exact thing as Sloth, no vibrations at all and though my bass is usually tweeked very neutral like Sloth, during testing and experimenting, no vibrations under high bass outputs either PS: Thanks Sloth.

Ah, the light shinith brightly....VERY BRIGHTLY! SICAONE: "I was just explaining what was pleasing to my ear" SLOTH: "...you keep missing the basic premice of audio, if it sounds good to your ears, then go with it. Right or wrong, that is the bottom line." Boy, miscommunication abounds. And: there is no "wrongness" involved. I've been discussing hi-fidelity, high quality, sound reproduction that religiously replicates, as closely as possible, the sound in such a manner that you have an audio listening experience comparable to having been at the actual recording session, concert hall, symphony hall, etc. But you (y'all??) are talking about the actual "listening experince" as with reproduction techniques modified to fit a given environment. Now, first I must say that I have never seen a spectrum analysis of the "white noise" comprising the typical automotive environment "at speed". But my suspicion would be that it starts well above the "bass" level, probably even above the high end of the bass level. What that would mean is the "best" "percieved" listening experience might result from the "filling in", "excentuating" of the musical content below where the automotive noise spectrum begins. But even so, I remain uncertain as to whether the same thing might not be accomplished just tweaking the "bandpass" excentuating the lower frequencies and then let the OEM speakers do the job, assuming something like a Bose or ML system, or high performance speakers of any modern design/type. And, carlos, I hereby retract my offer until I have a chance to use a spectrum analyzer to verify that my factory supplied speakers will provide as much "boosted" low end bass fill in as a twin 5" tuned enclosure with sub-woofer amp and bandpass filter. I may do that by simply turning up (dramatically) the Bass level on my sub-woofer/amp equipped LS400 and then verifying that the OEM C4 system will meet the same criteria using the spectrum analyzer to compare.

What do I do...??? Well, mostly my reponsibilty is to drive my wife to work each day, and then drive her home in the evening. In short, I guess you could call be a "kept man". As long as she will have me, I'm perfectly willing. You can look us over, and the company we founded in 72, at strobedata.com. And a bit more at teamseattle.com. My career, life's work, has always centered around electronics. Moved into the world of digital computers in 1969, haven't had time to look back since. Back about 87 some idiot made me a "manager", but by then my electronics skills were pretty out-dated with respect to what the company was doing and the skill level and skill set of most of the employees.

ER996: If you go for the footwell location, go with the 10" - the two fives won't produce much "real" bass. Two 5's just can't move much air. The Porsche/Bose system uses 2 fives, and it produces a lot of midbass, but very little "low" bass. Definitely look for another source for the rear deck box. $2k sounds like a LOT! I think you'll get the best low freq's because you'll be able to get a larger enclosure back there, which in turn will get you bass that goes lower. Will sound much more accurate. Not to mention, you won't have to tear up your car. Good luck!

well I managed a 10w3 in the back and it's extremely low and takes up no space, almost the same as the bose. I am a finatic with audio and built my own box out of mdf 5/8's and got the precise airspace inside and of course caulked, sealed and carpeted it all myself. The result is truly amazing for one 10. It is a 10w3 d4 granted running dual 4 ohm voice coils together at 2 ohm as my ppi 5440 amp sees it on the single channel. it is rated at 150 @ 4 Ohm and at 2 ohm I figure it's at about 200 or so. It is very clean and I am not even close to 1/2 for the gain. I do need to get an external crossover for sure though as the one in most if not all amps suck. They just skimp on the frequency roll off. I would have done this sooner but just got into accident so who knows if the car will even be around, I hope it gets totaled out personally as anything less than pretty much perfect annoys me. buy the way I must say and I have said it before Carlos' box is gorgeous.

Thanks SPR. Have you guys tried Poly-fill? its and easy trick I have used for years and works well. By increasing the air density inside the box, the box behaves like a larger airspace box yielding a fuller sound, just like that! Here is an old article explainig it http://www.integracaraudio.com/carau...ces/fiberfill/

Carlos: That is a beautiful installation but may I ask what, or where, did you locate the airflow, bass tuning port, it isn't visible anywhere in the pictures.

Ahh thats because there is none since its not a vented/reflex enclosure, its a sealed enclosure so there is no ports. I opted for it because I personally like the tighter quicker bass it yields compared to the vented or bandpass enclosures (I have had all three types) and though it yields less amount of bass from the same drivers than enclosure types that use ports, the sealed two 10"s inside the cabin is way more than enough already. The other reason is the less airspace needed in its construction since there isn't enough space for the size that is needed for a vented box of two 10" drivers

twin 10", less bass, same drivers. "Tighter quicker bass." As your 10" speaker cones move forward a vacuum is created within the sealed enclosure, making it progressively harder for the driver to move the cone farther. Conversely, when the driver output reverses and the speaker cone wants to move backwards the vacuum will really help. With that sort of non-linear drag or damping I really surprised that the level of audio distortion you get isn't more noticeable. I suspect that a lot of "audio" sins are encompassed in that statement of "tighter quicker bass". What you are most likely hearing is a high level of harmonic distortion of the original content due to inordinately slow forward movement of the speaker cones and then relatively quick return, backward, movement. But again, there is no "right or wrong" whatever rings your chime.

Not quite, I didn't make up those concepts about tighter bass, its a well known standard description of the bass type from the different boxes. Sealed boxes are know to yield what is called "tight" bass and bandpass boxed give more whats called "booming" bass, while vertex is somewhere in between the two. Its really simple, sealed boxes = less bass because there are no resonance ports that increase the bass output, and a bandpass even more so, I have a 10" bandpass that will render your rear view mirror completely worthless from the shaking . And tighter quicker bass because its not as booming due to the vacum shoterning the excursion in time and lengh and no trailing resonance from those ports that increase the output through resonance. Hence sealed boxed are used when you want a "cleaner" bass which actually distorts the bass less, you get more of a sharper quicker kick (tight bass) and less of the longer deeper softer boooom (booming bass). So you have it the other way around. Thats why sealed boxes are used more for classical music, jazz, blues, rock etc. and vented/bandpass for rap, techno, etc. So one is not better than the other it just depends on how you personaly like your base. But the best way for you to see it is to listen to both boxes on the same stereo and play your favorite tweeking cd's

In the mid-fifties I had a neighbor/friend who played the guitar and sang. Except for his redition of Gogi Grant's "wayward wind" I always thought he was better at playing the guitar than at singing. Shows how very wrong one can be. In any case we added an electronic pickup to has standard guitar but then he came back asking for something "special". I tried several things, even rewinding the guitar pickup at least once, but couln't quite get the sound he was asking for. Later I learned that he had heard another guitar player who had added "fuzz" using a special amp delay line feedback arrangement. Carlos' sub-woofer arrangement brought that back to mind. I've been setting here being denigrated for suggesting ways to have something close to high fidelity in an automotive environment without knowing that the sub-woofer market has gone elsewhere, "tighter and quicker bass". One of these days I would like to put a spectrum analyzer on that just to see what, exactly, the statement means. But, meanwhile, Carlos, and everyone else with these "special" sub-woofers, enjoy the sounds.

Going at it again West? ...if you do your research on car audio before you talk you will see that they have nothing "special" and you would know what it actually meant what I said. Unfortunately, is going to continue a mystery to you since I'm not the one to waste my time to explain it to you.

First, an admission. I haven't a clue as to what Carlos, and apparently others, are hearing when they describe bass sounds as "tighter and quicker". Carlos himself has admitted that his two 10" sub-woofers do not perform as "well" as they might absent the poor compliance resulting from the (restricted air capacity) sealed enclosure he is using. Yet he seeming gets upset if I suggest that two 5" speakers in a tuned enclosure would yield better fidelity and equal volume. So, this post is only for those of you with an open mind. COMPLIANCE is a really big word for speaker designers. Basically it reflects a willingness of the speaker cone support structure, inner and outer, to allow the speaker cone to move most easily at the "command" of the electrical current flowing in the voice coil. In the case of a sealed enclosure with restrictive air capacity the efforts of the speaker designers are wasted. The forward movement of the speaker cone is constrained by the level of vacuum created on the backside due to forward movement. So forward "compliance" is severely contrained. And now when the voice coil current begins to reverse and we have a most willing speaker cone, the vacuum will now help to move the speaker backwards. Carlos 10" speakers in his sealed enclosure are most decidedly NOT following the commands of the sub-woofer driver amplifier. Now, be-that-as-it-may, Carlos may quite thoroughly enjoy his unique sounds. But to pretend that his system is religiously replicating the original recording is a bit off the mark. My suggestion would be that if want hi-fidelity sound reproduction, when you go into an automotive audio shop and they start selling sealed sub-woofer enclosures, or anything but sub-woofers mounted in tuned enclosures, or a sub-woofer setup with lots of air space behind (the LS430 uses the entire trunk space), then run the other way, FAST. And I still stand firmly on my position that the OEM speakers in my 01 C4 or any Porsche Bose system will product much better, higher fidelity, sound reproduction, at equal volumes, bass included, than any system including a really good high fidelity sub-woofer. So, if you really like listening to Carlos' version of bass reproduction, still, high levels of distortion included, then put down your money and go for it.

West, you have no idea what you are talking about, you can't even understand what I say, as you seem to misinterpret everything I say, thats why I'm not even going to bother correcting those in your previous post and neither correcting all the misconceptions and errors of your post bit by bit as I done before. So like I said before do your homework first on car audio and maybe then you will understand why things are the way they are and stop confusing people with your faulty theoretical reasoning and I quote "bla,bla,bla.." without any experience on it. Its as easy as hearing the differnces yourself at a car audio convention/competition or profesional installer shop, but looks like you don't want to do that, and keep contradicting everybody for some reason. BTW 2x10" sealed is one of the most common subwoofer solutions out there for car audio upgrades due to its advantages among quality sound, ease of construction, versatility of reproduction and smaller space. I would love to take credit for it but its not a personal invention of mine for my particular ear. I don't know why I even bother replying, everybody else seems to ignore you in this matter by know, I guess I'm slow...

Here is some good reading on making bass, subwoofer enclosures, and the benefits and drawbacks of each design. Granted it is from a sub mfg., but it is general enough to apply. Subwoofer Enclosure Reading

Yes, its from a manufacturer but they are great reading, they are quite known and have been around for a long time, I remember going through those over 7 years ago I think. JL Audio is one of my favorite subwoofeer manufacturers and have a great reputation. Here is a reference thay make there as to what is refferered as tight bass in sealed enclosure since West has difficulty grasping that concept: "Transient Response Transient response refers to the ability of the subwoofer system to reproduce quick changes (transients) in the program material accurately. This is often interpreted as "tightness" or "looseness" which is maybe a dangerous terminology since many people are more influenced by tonal characteristics when asked to qualify the "tightness" of the bass. Transient response is actually a function of accuracy in relation to time rather than frequency. In music, sounds like drum strikes and quick bass guitar pulses are good tests of a subwoofer system's transient performance. A system with good transient response will reproduce these sounds with clear, "tight" definition. A system with poor transient response tends to blur these sounds over time, due to the speaker's inability to stop and start quickly enough to react to the signal accurately. It is generally accepted that an optimized sealed enclosure exhibits the best transient response characteristics."

A little translation in your wording perhaps? wwest: substitute "transient response" for "compliance". Carlos: substitute "compliance" for "transient response". I don't quite see how it is that you are both saying the very same thing but can't seem to understand each other. And Carlos, I don't know very much at all about the subject but it would appear to me that your sealed enclosure is probably "optimized" to fit your 911, not an "optimized sealed enclosure" as referred to in the article you referenced. Not an expert in any sense of the word but it is really hard for me to believe that there is enough airspace inside your enclosure to allow any reasonable level of transient response, compliance, for two 10" speakers.

Theory & practice. It is a very well known theory, at least in electronic engineering venues, that reducing the gain of an amplifier, or an individual component within, serves to increase the measured bandwidth. To put it simply, the half power points (3db down on the gain/bandwidth plot) are now farther apart, ergo, more bandwidth. That's what the last powered instrument aboard the Pioneer 10 was set to measure, the HPP of the solar wind. Regretably at about 8 billion miles from the earth we lost contact with it's 10 watt transmitter. But at least we now know that the solar wind's HPP is more than 8 billion miles from the earth. For whatever that matters. With a sealed enclosure to reduce the 10" speaker's compliance ("GAIN") you have in essence increased their responsiveness, but with regards to bandwidth only. If you were to turn the sub-woofer amplifier's gain/volume up to the point of equal performance to, say, a couple of 5" speakers in a tuned enclosure, you would undoutedly have your ears insulted with the level of distortion created.

Juan, thats one of the advantages of sealed enclosures. Sealed enclosures need much less airspace than ported/vented boxes (bandpass need even morte space) and also that airspace needed is not an almost exact figure like in ported boxes, sealed boxes are much more forgiving in that aspect and there is a wider margin of airspace allowed. In this case, there is enough space between the rear seats for a 2x10" sealed enclosure (the space which the driver needs in a sealed box may vary from driver to driver, and the manufacture gives that max and min figure) but not for a 2X10" ported one. I could have gone with 1x10" ported or bandpass, but I preffer sealed 2x10" which is less efficient box though but in turn you have two drivers of 10" and veryb importantly, at the gain that you can play them inside the car you are not even close ever to getting any distortion (you can trash West's last post again about gain/distortion as you can see... no clue ), also even though the sealed boxes reproduce/perform better at low bass with a quicker transcient response, they don't perform as well as ported in higher bass freq's but if you include 2x6" woofers in the doors, you can't tweek the system for those to start to take over at those freq's (crossovers, etc). Whatever box you fit, you take it into account when designing the whole system to compensate for the disadvantages of each enclosure, so thats why there is no "right" box. So for the 966, the most popular solutions are 2x10" or 2x8" in a sealed box, but you could also fit a ported box though its construction will be much more difficult since the space behind the seats is very irregularand very limited.