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E36 Stereo Upgrade: Additional Comments

Several additional comments after completing my stereo upgrade:

The term speaker is a bit misleading, especially when a system involves
multiple units, as the ones found in the E36 packages. It helps to think in
terms of "drivers" (high, mid, and low) or by the names "woofer",
"mid-range", and "tweeter". 

The oem system in my  318iS had (2) 5 1/4" low drivers in the kick panels,
(2) high drivers in the doors (1 in each door) and (2) mid drivers in the
rear deck. It is my understanding that the 10 driver systems employ a similar
pattern but add a Mid driver in each door, and (2) high drivers in the rear
deck. The high drivers in the rear deck are hidden under the covers with the
mid drivers.

The biggest complaint that I have heard, is the lack of bass that is produced
by the oem system. I would qualify my dislike by calling it a lack of tonal
quality at the lower end. You can add more "thump" to the rear deck and kick
panel drivers by increasing the insullation in the enclosures, but I wouldn't
call that improving the bass.

The cause of the problem is two-fold; the power supply (I can't say
amplifier, because in some early production models, mine included, there is
no seperate amp) and drivers. I've been told by dealers that the 6 and 10
driver systems use a seperate amplifier that is located on the Driver's side
in the deck/trunk area. No one ,however, has been able to provide me with
specs on said amp, but let me suggest this: in a system that utilizes the
"seperate" oem amplifier, if you can turn your volume control to 40%, with
the bass level 2 or 3 clicks above "even" and you hear distortion from the
low driver in the rear or kick panel, (especially the kicks), then the oem
amp isn't worth the ink it took to list it on the window sticker. Since I
haven't listened to this type of system personally, this is only my opinion.

The drives in the oem system are marginal, and IMHO, something less. I
attempted to passify myself by replacing the kick panel and rear deck drives
with limited success. After two weeks though, it became apparent that I was
wasting good "speakers" on a non-existant amp and still had marginal sound
quality. I had to bite the bullet, and go for an amp.

For anyone with the 6 drive system, a speaker upgrade alone will not
completely solve the problem. If your car has the seperate oem amp in the
rear, installation of an upgrade won't be much trouble. Without a seperate
oem amp however, you'll have some restrictions.

The non-amp units have a small power supply in the dash head unit that I'm
told generates a max of about 4 watts and does not have RCA pre-amp outputs.
( I can't believe Alpine would even consider such a unit.) For those
wondering, RCA "jacks" are just like the patch cable ends used to connect
your home CD player, VCR, or tape deck , to the receiver or amplifier.
Instead of RCA outputs, the oem dash unit wires directly to the speakers.
What this means is that you can't choose an aftermarket amplifer that relies
on RCA imputs, which MANY do. For those of us in this boat, there are two
alternatives, "speaker level imputs" or "line output converters".

An amplifier that will accept speaker level imputs will use the powered
signal coming from the dash head unit via the speaker wire and does not have
special connectors (RCA jacks). The amount of power from the head unit that a
speaker level imput will accept varies with the amplifier, but most will
accept as much as 25 watts.

Line Output Converters vary in size, with the biggest I've ever seen being
about the size of a paperback book. They accept the powered signal via the
speaker wire and convert it to an un-powered signal with an RCA jack, that in
turn, can be used with a wider variety of amplifiers. They're also known as
"high to low " converters. I chose an amp that accepted speaker level imputs
over the line output converter method because some LOC's have to be powered,
and they take up additional space.

The next consideration in amp selection is 2 chanel vs. 4 chanel. A 2 chanel
amplifier powers 1 left and 1 right "speaker". A 4 chanel amp sends power to
1 left front, 1 left rear, 1 right front, and 1 right rear. Each chanel has
seperate  output, so each  can be isolated by the head unit. In order to keep
the fader, the ability to choose either the front or rear speakers at one
time, you have to use a 4 chanel amp. Since I didn't want to lose this
feature in the upgrade, I had to go with a 4 chanel. Now for the tricky part;
many moderately priced 4 chanel amps with speaker level imputs (under $200) ,
only have 2 chanel INPUTS. This means that the signal coming from the head
unit into the amp is only imput as left & right, not left front/rear & right
front/rear. Ergo, you lose the ability to fade the speakers front to back.
You have to specifically determine that the amp has 4 chanel INPUT, as well
as being a 4 chanel output unit. Power is the last consideration, don't go
below 25 watts per chanel.

There are several other aspects of amp design components that you may want to
consider. For a decent explanation of things like regulated power supply,
discrete output devices, THD, MOSFET and others, call Crutchfield at
1-800-955-3000 and request their catelog. 

Amplifier Installation: the one saving grace of the E36 electrical design, is
that the battery is in the trunk, which makes it easy to wire the amp for
power. You'll need to run a lead to switched  power so that the amp isn't
constantly drawing power from the battery. The typical place to go would have
been to the power antenna, but since the antenna was moved the to rear
windshield, that was out. The next closest lead, and actually just as easy to
tap onto, is the power lead that runs to the antenna power boost. The unit
itself is behind the trim panel on the rear drivers side C-pillar. The wire
is white, with no other markings and runs under the rear deck for several
inches before going to the front of the car. You'll need to buy some extra
"on/off" lead wire, the amp's length is usually less than a foot.

I placed the amp on a wooden panel that I made to sit in the groove that
holds the lug wrench. I wrapped the wrench in a towel and placed it in the
spare tire well. From this location, it is easy to run the remainder of the
wiring above the right side trim piece to the amp. As a finishing touch, buy
a small piece of flexible black rubber tubing, about 3/4" dia. Slit it down
the length and use it to encase the several inches of exposed wiring.

Speaker/Driver Selection: the choice of speaker brand and model is a matter
of personal taste, and there are several trade-off's to consider. The easiest
way to get exposure to many different brands is to get the Crutchfield
catelog. (I don't work for them.) Note the brands and models, and them go to
a local audio shop that carries those lines and try them out. The catelog
also has a chart for sizes that will tell you what will fit. On occasion the
chart has been incorrect, as with the rear deck sizes for an E36. If you
speak directly with one of the sales reps, they have updated data and can
confirm any corrections made to the current catelog. The prices are close to
full retail, not much mail order savings here, but the sales reps are
extremely helpful and don't press you for a sale. 

When auditioning speakers at a local shop, keep in mind the Obscurity
Principle. This law states that the price of a given piece of audio equipment
is inversely proportional to the purchaser's recognition of the
manufacturer's name.

Speaker/Driver Installation:  I replaced the rear deck and front kick panel
drives. As I had the 6 speaker system, I used coaxle drives in both areas. A
coaxle drive combines a low mid-range and a high drive into one unit. You
access the rear deck speaker boxes by removing the cover and removing 2
screws. There is a clip on the inner side of the enclosure that must be
depressed. After this, go to the trunk and slide the box out. (Hint: place a
towel on the rear seat to protect it and fold down the split seats and sit on
top of them during speaker removal.)

Most drives have 4 ears with screw holes for mounting. You'll have to bend
back 2 of the ears on opposite sides because the oem speaker box has 2 posts
that accept the box mounting screws, which are in the way.

The front drives require a bit more work. In order to get at the kick panels,
 you'll have to remove the lower dash trim pieces from both sides and then
slide them out. (Hint: if you have the oem alarm system the alarm unit will
not allow you to side the right side piece out horizontally. You'll have to
remove the glove box assembly. This gives you better access to the speaker
enclosure anyway.) 

The drives themselves are screw out, screw in, so no big deal. But you'll
have to make a decision on wiring to the amp at this point. Most professional
installations would cut the 4 lead wires at the back of the head unit, run
leads back to the amp for input and then run the outputs back to the cut
wires for the fronts and straight to the rears in the back. This,however,
involves removing the head unit from the dash and also running wire through
the console. And I didn't want to be splicing wire with my hands in the small
space in the dash for the head unit.

What I did instead was to take the original output leads, extend them, and
run them back to the amp as inputs. Then I just ran new lines for output from
the amp to the speakers. For the fronts, I ran the wires under the door jam
trim piece and then under the rear seats and behind the trunk trim.

Total installation time was about 6 hours. But if you take into consideration
the trips for  supplies that I forgot and also that I was doing this after
work, it took me three evenings. (I was driving around with no glove box and
half a dash for two days!)

This is by no means a professional installation or equipment selection
manual, but it worked for me. The total cost was about $350, which as car
audio goes, is not much. Yes, you can do more, and spend more, but it would
bother me to dump big dollars into a car that should have had a quality audio
system included in the first place. If there's anything I left out, let me
know.

Regards,
Jeff
93' 318iS
84' 318i