I ran a real-time analysis of the system using the following parameters:

pink-noise source via test CD
1/3 octave resolution (30 bands 20 -20kHz)
3-sec smoothing
measured with an Audio Toolbox Plus RTA with calibrated microphone

I took 10 sec-measurements at driver's ear, center front, right front
left, center, and right rear

I then averaged them:

Here is whatr I found:

1) As expected, bass is too heavy when engine off. It was up about 15 dB at 50 Hz. I set it down 5-bars to get the bass balance more natural. Of course, when the engine is on and the car is moving, ambient noise will tend to offset the bass boost, so I recommend a -1 bar as a good compromise

2) Midrange was very smooth - there is a null of about 6 dB at 400 Hz irrespective of position, which I attribute to modal effects caused by the interior dimensions.

3) There is another drop of about 6 dB at 1800 Hz - this is the low treble, and may account for the feelings of a need for a tweeter. Setting the treble to +2 bars smooths it out

3) Above the treble null, the highs are very smooth and extended, down a few dB at 12k, and rolling off at about 6dB out to 20k. This is nearly a perfect profile based on psychoacoustics (flat response to 20k is invariably perceived as very bright).

So I do not see the need for the tweeters - it is my experience that some folks unaccustomed to the sound of natural iunstruments go for a very boosted hi frequency - the "sssss' sound. That is personal preference, but the system is pretty well balanced from a frequency response perspective.

 

Sounds just fine to me!
Ed

 

no complaints here either.

i will try what you suggest.

bass on -1 and treble +2 right?

 

My settings are set because of the music I listen too. Being a young brash teenager I have to have my bass set up just a little, +3 I think, and I have my treble at +1. For some reason the treble seems weak...

 

RR: Your measurements confirm my suspicions! I've always had my settings at Bass -1, Treble 0. I've noticed that the bass was very boomy, even during driving. I've also noticed that there is a lack of punch in the mid-lows and mid-highs (corresponding to the notches at 400 Hz and 1.8 kHz), but boosting the treble makes the real highs (>2 kHz) annoyingly loud.

"No highs, no lows, must be Bose".

 

I dont know but that one sub in the window isnt enough bumps for a player like me...I just have a little back up bass in tha trunk for those times when im really crunk...Shyne

 

I have it on max bass and max tremble.

 

Road Rage,

I hope I'm welcome to throw my opinion in here. I am one of those many people who is of the thinking that the stock Bose setup in my 02' TL-S was, quite frankly, crap.

Now let me mention 2 things quickly so that no one thinks that I am attempting to sound like some I'm-better-than-you, "I'm a musician and an audiophile, blah blah" type person. First, I do have an appreciation for excellence in sound reproduction, though I don't use the term "audiophile" because of its snobby connotations. Second, to balance my opinion, let me mention that I was entirely happy with the stock Bose system in my last car, a 95' Maxima, so I don't expect the world from a car stereo. Now with my response:

I too, used an Audio Toolbox to record the response curve of the stock system (though admittedly not from as many positions as you have).

Regardless of what my ears were telling me, the data I recorded using the AT was far from "acceptable", let alone "good". Unfortunately, I never saved this data in the AT or to my PC (but who cares, this is just my opinion ).

Even without the AT, some of the stock Bose system's faults were easy to detect (faults that don't necessarily show up on an RTA even). The worst were probably the overall lack of transient response (bass drum thwack, snare hits, 'tink' of a cymbal), *awful* upper-mid/low-treble ringing in one particular area (easily heard with most female vocal recordings, I remember Alanis Morisette (live) and Enya albums reacted particularly bad), and lastly, an awful lack of response in the treble range, with little or no detail at all. (again, this is all just my opinion, and I'm only as much of an expert as I *think* I am :p )

So, yes, I replaced the stock door speakers, and added tweeters like so many others. Since I was bothering to do it, I went with components I really trust (Focal).

While I'm at it, I'll mention that Bose's approach to attempting to produce full-range, natural sound (using no tweeters and 6-inch paper cones with magnets no larger than an overcooked breakfast biscuit was to process the %@$^ out of the signal in an attempt to fix the deficiancies. I used the AT to do an analysis of the output from the Bose EQ a while I was replacing my speakers.

see my post in the Audio Forum, and look for the EQ graph:

http://www.acura-tl.com/forum/showth...threadid=20860

Another example I can give regards my own instrumental recordings. Imagine a sound-quality scale of 1 to 10. If at the studio, those recordings sounded "perfect/10", and sounded "excellent/8" on my home stereo, then sounded "pretty good/6" in my old Maxima, then I would have to rate the stock Bose system at a "below average/4". Stuff was just missing, and/or plain didn't sound right.

So in summary, if you personally are happy with the stereo, rock on. If you aren't, fix it with whatever makes you happy! And unlike was suggested, "some folks" who add tweeters and the like to their TL Bose stereo aren't necessarily untrained listeners (Ok, ok, there are those dorks who, for some reason, like you to hear their bass and treble at terrifying levels 100 feet away, - can't even IMAGINE what that sounds like IN the car!).

And so it doesn't sound like I'm a picky person in general, the stock stereo is the only component of the TL-S I have any gripe with, aside from very minor build quality issues.

Responses/flames welcome!!
AllanC

P.S. - Do I sense a move to the audio forum?

 

Good post. I mentioned that this was not a subjective assessment. I have an EE and write for a high-end audio publication in addition to auto stuff so I know where you are coming from. The quality of the drivers can certainly be improved, and if people are overdriving the system into clipping, the resulting harmonic non-linearities will certainly make it sound worse. Still, it is an unassailable fact that linearity of freq response is the prima notta of an audio repro system, and in that regard the system does pretty well.

I use 14 channels of amplification in my home system, feeding 11 SOTA speakers. The system is flat from below 17 Hz to 20k. So I know where you are coming from. (I actually hardly ever listen to music in cars, as even the finest system is a mouse compared to my Big Dog system.) Rush sounds good enough on AM. What is interesting is that for most people, their cars have far better sound and attention to placement than they ever get in their homes. And then there is MP3...it does to music what Hitler did to Poland. The danger is a gen of kids coming up with no grounding in what "is" is. Plus, there is mounting evidence that boosted hi-freq is causing ever increasing #'s of mid-20's adults to have hearing loss beginning in the 5-7k region, and 1/3 of the population is tone deaf above 10k! Watch those ears!

 

I take it from your post that my settings of bass 0, and treble +6 is pobably bad. I'm not sure but that's what I think it sounds best at. Maybe its the music I listen to? But I find plenty of bass from the system but not enough high/mids, which is why I have my setting like that. Most of the music I listen to is bass-heavy anyway(hiphop, linkin park, house, etc. so I turn the treble up to compensate, but from ur post maybe I'm just tone deaf at high khz?

 

The settings that I use depend on the volume that I am listening at.

At high volumes, I find that the best setting is treble as low as possible and bass as low as possible.

I agree with the observation that the biggest problem with the woofer is that it sounds like a cardboard box and is very sloppy. Furthermore, the crossover frequency is 200hz where you can clearly tell what direction the sound is coming from (theoretically, below 80 Hz is omnidirectional).

At low volumes, I use a setting that is closer to neutral with the bass down two or three ticks and the treble down 1 or two ticks.

I do consider myself an audiophile and listen to everything from acoustic jazz, classical to pop, rock, and hippop.

 

The settings are personal, but a +6 makes my ears bleed. If the engine is off, I drop the treble -1. If I am cruising around, +1. The variations Hemants mentions are due to the fact that we perceive sounds differently at different volumes, hence "Loudness" controls. Were this not the case, we would be deafened by the low frequency roar of nature all around us. There is tons of low bass and subsonic info generated when a car is rolling, and it tends to overwhelm the woofer, hence the bass boost at 50 Hz.

Bass is non-directional below about 80 Hz as mentioned, but bass re-inforcement is a function of volume, so it starts higher in frequency in a car than in a house, which will make the problem of the high crossover less troublesome than it might have been.

 

Good points Road Rage. Most of the stuff you are talking about deals with frequency response issues.

The bottom line for me is that the sound kind of sucks. I am an EE too and used to agonize over why but have found that audio perception and audio measurement do not always correlate very well.

One other thing I would add that deals more with Bose home speakers but also to the car system is that the seperation of woofer and tweeter can never sound as good as a speaker with sound originating from a single source.

I have JM Lab speakers at home that go down to 35 hz and I have a Sub woofer that I use for home theater but I have to turn it off when I listen to music because it gives me a headache; even if I set the crossover to 80 Hz or below.

 

good posts both of you!

For those of laymen, the problem I have with Bose is what I term musical accuracy, which is along the lines of what I think alanc45 was driving at.

When I picked the speakers for my home system, I went for those that you could here sounds that other speakers wouldn't produce (fingers on strings, the inhale of a woodwind section, etc). Bose was the first and most obvious loser in this test. I wound up going with M&K - really like their stuff. If I was made of money perhaps Watt Puppies (sp?)....

So Rage, how would you term this in technologic jargon?

Sota? I thats one I haven't heard of...

 

Heh heh and I guess JPG does to 2-D art what Hitler did to Poland as well

I agree. I see a disturbing trend these days: teens seem to prefer oveboosted highs as well as booming lows. I can understand the lows for their "beat" value, but the highs simply hurt my ears; there's an increasing number of young people who have lost their high-frequency sensitivity!

 

SOTA = state of the art

JM is good stuff - Focal drivers are fine, except that inverted titanium driver has a low-Q resonance in the 15k region.

To all: I am not saying that because the Bose/Acura system measures pretty flat it is "phat". There are many other issues with speakers that affect ultimate perception: energy storage problems (ringing), non-pistonic break up, dynamic offset problems when the magnetic ring goes out of the magnetic field's area of linearity, etc. These can make identically "flat" speakers sound different - it is called "clarity" or "focus" or "timbre". Bose can EQ a cheap driver to make it sound pretty good - but you cannot make a silk purse out of a sow's ear. The 901 series proved that.

Nearly all the other measurements and sound do have causality - amps, pre-amps, cables, etc. Identically measuring transfer functions sound the same. I have confirmed that in 100's of controlled double-blind tests (not audiophile A-B "tests").

The only real subjective area is speakers and the filtering and dithering schemes used in DAC's.

 

I think it's important to note that there is no "right" or "wrong" to the bass/treble settings. If there was a "right" setting that the controls should be set to all the time then Acura/Bose would have hardwired those settings in the system all the time and you wouldn't have any adjustment knobs. RoadRage presents an excellent analysis of the Bose system--from an engineering standpoint (RR, I'm not slamming you at all--I know you're very knowledgeable in this area--I just want to make sure people understand the difference between specs and sound). If all you wanted to reproduce was pink noise from your system, then the settings he gives would be correct. But the problem is different recording materials and different volume levels make the problem more complex than a fixed setting.

Fletcher & Munson's work on the phon scale illustrates this clearly. Your perception of the loudness of a particular frequency and it's acutal loudness can be quite different. And nowhere is this more pronounced than in the lower frequencies. Lower frequencies tend to sound softer than they really are at a lower SPL. This is why many home stereos have a "loudness" button. Engaging this circuitry artificially adds amplitude to low frequencies to make the material sound more "flat." If you left this button in as you turned up the volume, eventually it would sound like there was way too much bass.

Likewise, not all commercial CDs are mastered at the same level. Some engineers mix in heavy bass on the master (or use heavy compression) to give the sound a big bottom end. Many do this because they like the sound, and some have claimed to do it because they are anticipating the type of equipment that will most likely play their music. Example: My Boys II Men 'Evolution' CD has an inordinate amount of bass mastered into it. If I don't adjust the settings in the car it sounds way too boomy. However, my Little River Band's 'Greatest Hits' CD (no smart remarks please) is mastered very flat, and suffers from a lack of bass when played in the Acura. I make adjustments accordingly.

The moral of the story is: treat bass and treble like salt and pepper at the dinner table. If the meal is cooked right, you shouldn't need to add any seasoning yourself, but occasionally you may need to make a slight adjustment to suit your tastes.

Use bass/treble sparingly and add (or subtract) to "taste."

Remember the bottom line: If it sounds good to you then it's set right. That's all that really matters.

 

I agree. I think it great that we have members that have the knowledge and equipment to do that type of testing.

What people do with the results are up to them.

 

Wow RR, sounds like you've done a lot more study on this than most magazine writers

Just curious, when you say transfer function, do you measure both impulse and steady state response?

Also, remember that statistically speaking, a Null result (or 100 Null results for that matter) of difference between A/B doesn't prove that two things sound the same, only that no difference was found by those listeners, in that environment, using that music, on that day.

 

Umm....are you planning to live a long life? If so, how about the concept of having your hearing intact down the road a few years when you no longer consider yourself "a player"? People change, they grow up, mature, evolve, and one day you'll look back and say to yourself "what was I thinking?".

Think about all those self-destructive people out there on the streets...listening to that rap....music?....stuff really loud all the time. There's gonna be a lot of hearing impaired people out there some day...and its gonna be sooner than one might think.


By the way, I love this thread. I'm gonna set my bass and treble according, so thanks alot!

 

Keep in mind there is a big difference between subjective listening tests and objective listening tests.

You can do a very comprehesive audio waveform analysis which would suggest that the music sounds good but subjectively if you listen to it, it may sound terrible.

My opinion is that the system is adequate, nothing more. You should be able to "feel" your music not just hear it. There are certain frequencies which contribute more to that "feel" sensation ... if you listen to MP3 compressed music you'll know what I mean. The sound is there but you can't feel the crisp highs and deep lows.

I usually set the bass to about 0 and treble to +2. Even with that, I find that the music lacks clarity and detail ... typical of all Bose systems.

But then again, that is my subjective opinion ....

 

Responses to numerous contributors:

1) Transfer function - I usually use steadt state. I also have ETF and MLS for impulse testing

2) RE: A/B tests Yes, it is as you describe, but it goes a long way to separate out what is and isn't audible, and who is full of crap and who isn't. In open tests, people hear all sorts of things as they interject biases of all kinds. In a controlled A/B, they learn that amps with similar specs are indistinguishable.

3) Re: objective vs. subjective I disagree. Only transducers and DAC filters are clearly audible. Most everything else is simply determinstic. That is, two amps of similar noise, distortion, linearity, when held below clipping, will sound identical. I have proven this to my satisfaction through 100's of controlled tests, and this is the prevailing opinion of most designers except hi-end types. If you can find one tenured professor at an accredited EE school willing to go on the record in dispute of this, please let me know.

 

I can't stand rap music, but if people want to listen to that sh!t, let them live and be well. I am 37 years old, still love rock and roll and still listen to it too loud. I am sure that my hearing is going to suffer, but one good side effect of that is that I won't be able to hear when people tell me not to listen to my music too loud.

The system in the TL-S is acceptable, but it really needs some solid bass.

 

RR, you and I both know that there is a lot of Voodoo in hi fi that hi-end companies profit from.

That being said, I don't think that the correlation between WHAT WE CURRENTLY MEASURE and what is audible is 100%.

Theoretically, everything that is audible should be measurable. But measurable is not the same as measured.

As a practical matter I can agree that most differences between components are exaturated, especially cables but I also think that subtle differences do not show up as statistically significant in an A/B test.

 

Man my head is spinning and I've got a headache trying to keep up with what you guys are talking about. :p

Should I get to the point of upgrading my system, which I surely would like to do, I'll be sure and post here for some advice.

BTW - I used to have a nice system in my 64 Malibu SS that would shake the walls in my parents house while sitting in the driveway. Mind you I didn't have a sub in it. Just a pair of 3-way Pioneers I think and a some 2-way doors. There were 2 Fosgate Punchs running through a 2 input passive tuner. I was so fond of it I was thing of duplicating in my TLS, but it sounds out dated from what you guys are talking about.

Anyway, sorry for the rambling and keep up the good stuff.

RUF

 

Tell me a better stock car audio system. It sounds great to me. (for stock)

 

a stock system in a car that's in the same price range as the TL?

 

Shee-it! After just reading this thread I think I'm ready for the mid-term!

Good stuff!

V.

 

Crap. I generally like my food salty. But, if there was one thing that I learned from this thread is that having a very high setting of Treble is more damaging than an equally high setting of Bass? Correct me if I'm wrong please. I know too much of both is bad...I'm just asking which one is worse.

 

From a hearing protection point of view, this one is easy - excessive hi freq signals are the most damaging. The tiny hairs which detect hi-freqs and link into the ear are much more fragile. Once they are damaged, they do not heal. There is some evidence that the bundles of hairs have some "memory" and that there can be some perception of hi-freqs even when direct detection is obstructed, but I for one prefer to take care of my hearing via ear protection and moderate levels. I am middle-aged but still have excellent hearing out past 14kHz.

 

So I take it it would be torture for a dog if you were to have them sit in your car with settings like mine. I think I'll turn down the treble a bit. thanks.