FAQ Section 13 - Car Audio

Good Links
-Sounddomain Forum
-Carsound.com (w/Forum)


How good is the stock 7-speaker stereo system in the Supra TT?
For a stock stereo system it does OK. It sounds clean and does have some low-end response. But if you love music, or consider yourself to be any sort of an audiophile the stock stereo will not cut it for you. The thing that the stock system is lacking the most is proper bass reproduction. The stock subwoofer is a paper-cone 5x7 in a small-ported enclosure, and is mounted in a poor location for strong low-end frequency response.


What part of the stereo should I upgrade first?
The stock subwoofer is the first thing that needs to be upgraded. Just upgrading to a 10” subwoofer with 100 or so watts mounted in the back of the hatch would be a huge improvement.


What about upgrading the head unit?
The stock head unit is pretty decent; the only reason to upgrade it is for personal preferences. Unless you are doing a full stereo upgrade, then it would be wise to install an aftermarket unit. When upgrading it, you will need to bypass the factory amplifier.


What size are the factory speakers?
The dash-mounted tweeters are 1" in diameter. The door speakers are 4" (3-bolt) and are mounted in ported enclosures. The rear speakers are over-sized 6.5" (6.75”). And the Subwoofer is a 5x7" in a ported enclosure.


Can I put 6-1/2 or 6-3/4 speakers in the front doors?
Yes. However they will require the removal of the stock speaker enclosure. The removal of this enclosure will leave a huge opening in the door so there will be no place to directly mount your speakers. You will either need to purchase or make a bracket to mount you speaker. The other option is to mount the speaker directly to the door panel. You must be careful doing this however. Not only is the factory door panel $1000 a piece from Toyota, but also it does not provide a strong mounting point for speakers (only the factory grill is fastened to the door panel). To make it so that the door panel can support speakers, you must make support plates that go on the backside of the door panel for you to fasten the speakers too (the speakers must be mounted on the front side/interior side of the door panel). If you don’t do this, when someone slams the door shut, the speakers will rip out of the door panel. What I did to install 6-3/4 speakers in my door panels was:
-First remove the door panel
-Remove the stock speaker enclosure from the door
-Remove the factory speaker grill from the door panel
-Find a suitable place to work with the door panel
-Carefully trim the factory speaker opening in the door panel to allow for fitment of the larger speaker
-Cut backing support rings out of ¼ MDF or hardboard, AND 20 gauge stainless steel or aluminum sheet.
-The rings must have the proper diameter inside cutout for the driver to fit through, yet narrow enough to provide enough space to support the fasteners. The ring itself must be around 2 inches to provide for enough surface area to support the load.
-Test mount the speaker and try to line it up so that you can use as many of the factory holes as possible, then drill the rest of the holes (you must have at least 4 evenly space holes). Make sure that the speaker will be centered.
-Transfer the pattern of mounting holes to both the MDF/hardboard ring AND the sheet metal ring.
-Go to the hardware store and buy 8 of the proper sized mounting bolts (with screw type heads) for the speakers, as well as 8 lock washers, 8 standard washers and 16 standard nuts (all the proper size for the bolts).
-Place the speakers on the door panels (from the front side) and put the bolts in place.
-Now spread a film of clear silicone sealant on the backside covering the area the support plates will take (do not get excess silicone on the speaker) this will prevent resonation as well as keeping the rings in place.
-Now line-up the board-ring with the mounting bolts, and slide it on till it contacts the back of the door panel, and seals with the silicone.
-Now spread a film of silicone on the back of the board ring.
-Now line up the sheet metal ring with the bolts and slide it on until it contacts the board ring and seals with the silicone.
-Press the rings down firmly.
-Now put the washers on the bolts, followed by the lock washers, then 2 nuts on each bolt, tighten finger tight.
-Now double check that everything is lined up ok.
-Tighten down the inward nut, but do not over tighten, just enough that everything is secure. If you over tighten you can crush the board ring and the door panel.
-Now tighten the second nut against the inward nut. Use two wrenches to tighten the nuts against each other. That will lock the nuts in place and keep them from coming loose.
-Let the door panel sit so the silicone can dry.
-Now take care of the wiring and re-install the door panel, and your done.
-I have had mine mounted this was for a year now, and it has held up perfectly.


Can I just upgrade the factory amplifier?
It is recommended that the main speakers, head unit, and amplifier all be upgraded at the same time for compatibility reasons.


Is it better to use stereo components that are all the same brand?
No. It’s almost never the case that any one company offers equally excellent products across their line-up. It would be wise to investigate each component individually. The only exception would be having main speakers from the same model and series. And subwoofers should all be identical to each other.


Is it safe to assume that higher dollar equipment will sound better?
While this can be somewhat true, it is not an absolute. The best thing to do is research as many components as possible, as well as listening to as many as possible. There are many times that a component may sound and perform better than another costing twice or three times as much. So do your homework.

It is important to note that the best place to spend your money is on the speakers / subwoofers, and a quality install. Against popular assumption source units and amplifiers, of similer "actual" specifications, do not produce noticably differing sound quality. 100 watts RMS produced at a low distortion level (and sound processing not applied) is going to sound the same to the human ear (trained or not) regardless of the brand name or cost. Richard Clark of Autosound 2000 currently offers a challenge that will earn you $10,000 if you can prove that statement wrong. Hundreds of professionals have accepted the challenge, no one has ever won! Now I am not saying there are not differences, because there are. Cheap generic amps usually have less effective X-overs or on-board sound processors, but when those are turned off that doesn't present a problem. Reliability, style, compactness, efficiency, extra features and percieved quality are all important and do vary between products.

The same applies to source units like CD players. If you are comparing two quality units, any difference in sound quality will not be picked up by the human ear. One note, "trained ears" are also usually atleast slightly damaged ears because of more exposure to higher dBs. Children and Women usually have more sensitive hearing, and they are the ones who usually don't care as much about perfect sound quality. Ironic huh?

Sound quality and performance differs much more in "drivers" (i.e. tweeters, mid-ranges, mid-basses, subwoofers) so I would recommend spending the bulk of your energy and budget in this area. And of course, the difference between a decent stereo, and a great one is ALWAYS the install and system tuning.

Here is a partial copy of Richard Clarks Challenge (Find the rest on Carsound.com):
THE $10,000 AMPLIFIER CHALLENGE RULES {April 21, 2000}
By Richard Clark
There is no question that all amps are not the same. It is very easy to measure large differences in the performance of amplifiers. This is true in nearly every known specification, including power, noise, distortion, etc. My experience has led me to believe that even though these differences can be easily measured, hearing those differences may not be so easy. Given the relatively small magnitude of performance differences, there is a giant step between amplifier performance and our ability to hear performance differences.
It is claimed by designers, manufacturers and especially salespersons that differences in amplifiers are clearly audible. Reasons include "obvious" advantages of one type of circuit topology over another. For example, it is claimed that certain designs have a smoother midrange response whereas other amplifiers exhibit tighter bass. Tube fanatics claim that tube amplifiers have that "warm" sound we all need in our systems.
Such descriptive terms are certainly subject to personal interpretation. It is not my intention to determine if one particular amplifier is better than another amplifier. Differences in the quality of the discrete components and constructions are more appropriate for settling the issue of "good - better - best." The sole purpose of my amplifier challenge is to determine if the differences in amplifiers are audible.

What differences are Audible?

I believe the perceived differences in amplifiers are all due to various factors that can be explained with basic physics and elementary psyco-acoustics. For instance, if two amplifiers are not carefully matched in volume, and one amp is slightly louder than the other, then it would be a simple matter to detect such a difference. In such an example it is important to understand that it is not the circuit topology, quality of the component, design excellence, or superb marketing and packaging that caused the noticeable difference - it was an error in the test setup! It is my present belief that as long as a modern amplifier is operated within its linear range (below overload), the differences between amps are inaudible to the human ear.

Comparing Amps

The idea here is for a test subject to scientifically demonstrate his/her ability to hear differences in amplifiers. It is our job to carefully match the amps so that we are comparing "apples to apples" instead of "oranges to frogs." This means that we sure wouldn't want to compare one amplifier that had + 12 dB of high frequency boost against another amplifier that was adjusted for + 12 dB of bass boost. Such a test would be easy to pass - even on identical amplifiers with consecutive serial numbers.
For our comparison test, we aren't concerned with which amplifier sounds best to the test subject. We only require that the listener be able to identify each amplifier when it is powering the speakers. Since many folks seem to believe that amplifiers have some kind of distinctive sonic character, this test should be easy to pass. Right? After all, we're talking about comparing those harsh sounding, high distortion, squeaky "widget As" to those warm sounding, smooth, bass hog "widget Bs."
Now pay particular attention to the following sections. Since we're looking for differences in amplifiers, and we already know that those differences are probably going to be very, very small, it is important that the parameters under our control be carefully adjusted so as to be equal as possible. This means that we must be cognizant of differences we might unknowingly introduce between amp A and amp B. They must be adjusted as identical as possible. We already mentioned the importance of volume. The same goes for the L and R balance. It sure would be easy to choose an amplifier that exhibited left side bias over a balanced amp. Right?
Well, in order to keep this amplifier comparison test fair, there are a few other parameters that must be considered.



What are some good head units?
I’ll list a few of the top lines:
-Alpine
-Clarion (Pro-Audio Line)
-Eclipse
-JVC (SH Series)
-Kenwood
-Nakamichi
-Pioneer


What are some good “main” speakers?
-A/D/S
-Alpine
-Crystal Mobilesound
-CDT Audio
-Diamond Audio
-Directed Electronics (DEI)
-Focal
-Image Dynamics
-Infinity
-JL Audio
-MB Quart
-Oz Audio
-Rainbow


What are some good amplifiers?
Good low cost amps:
-U.S. Acoustics
-Lanzar

Good moderately priced amps:
-Alpine
-Clarion
-Crossfire
-Directed Electronics (DEI)
-Earthquake
-Hifonics
-JBL
-Kenwood Excelon
-Kicker
-MMATS
-MTX
-Orion
-Phoenix Gold
-Precision Power
-Rockford Fosgate
-Soundstream

Good higher priced amps:
-A/D/S
-ARC Audio
-JL Audio
-Orion HCCA
-XTANT
-Zapco

Good HIGH priced amps:
-Brax
-Mcintosh


What are some good brands of Subwoofers?
-Adire Audio
-Alpine
-AlumaPro
-Audiobahn
-Audiomobile
-Beyond Audio
-CDT Audio
-Cerwin Vega
-Crystal Mobilesound
-DEI
-Earthquake
-Eclipse
-Elemental Designs
-Focal
-Image Dynamics
-Infinity (Kappa Perfect)
-JL Audio
-Kicker
-MB Quart
-MTX
-Resonant Engineering
-Rockford Fosgate
-Orion
-Oz Audio
-Velodyne


Would 2 12" subwoofers be enough?
What do you want out of this stereo? Eardrum popping bass output, life-like musical reproduction, or something in between? A high quality single 10” or 12” given appropriate power will put out a surprising amount of low frequency sound, and with great sound quality. Anything over 2 10” or 12” subs is probably going to be WAY overkill unless you are using bad equipment or have a poor install.


Where can I go to find a good deal?
Ebay.com, Ikesound.com, Thezeb.com, Sounddomain.com, and sometimes Crutchfield.com (always check in the “specials” sections)


Should I use Dynamat sound deadening material?
It is wise to use sound deadening material, but Dynamat is way over-priced. Check out www.b-quiet.com, or look for RAMmat on Ebay.com.


How much weight will the stereo add? Will that make a difference in vehicle performance?
It can add a lot of weight, and it does make a noticeable difference in performance. Try to keep things simple and to a minimum and you should be OK.

Mike T
94 Supra TT 6spd
"A naturally aspirated engine, is an engine with never-ending lag"

[This message was edited by Mike T on December 01, 2002 at 11:06 AM.]

[This message was edited by Mike T on December 02, 2002 at 03:45 PM.]

[This message was edited by Mike T on December 02, 2002 at 03:47 PM.]

[This message was edited by Mike T on December 02, 2002 at 04:20 PM.]

[This message was edited by Mike T on December 11, 2002 at 07:15 AM.]