C43 vs. C33

[OneImprezziveRS]

I tried searching, but maybe my search query is not good? What i'm trying to figure out is what are the major differences between the two and why the c43 is favored over the C33. I currently have the HK system in my 98 m3 with the c33 head unit.

Any input?

[OneImprezziveRS]

http://www.geocities.com/christyler5...E34E36E46.html

found it on m3forums.com

[M3Armand]

Copied and pasted from the link above...

E36 3 Series
Read the E34 section first to understand the amplifier/crossover design,
and wiring modifications necessary to add an aftermarket Head Unit. Chris

The Problem
The original sound system installed in the E36 3 Series was widely condemned for providing
poor quality sound. It tended to have screechy highs; A midrange that was dynamically compressed
and lacked warmth; and of course extremely poor Bass with no real power.

Some of these complaints were due to the earlier radio's poor high frequency response,
which was attenuated to mask electrical noise problems that were apparent at higher frequencies.
It also didn't have enough output voltage to adequately drive the external amplifier. Later models,
including those with CD (C43 or CD43), were vastly improved to address these shortcomings,
and in many cases performed as well as aftermarket units. It doesn't make a lot of sense to change
these improved models, as they perform quite well. But if you have an early model head unit (C33),
you'll benefit with a head unit from a newer model or an aftermarket system.

Reading the notes below, you'll become confused as you read contradicting opinions. But if you
remember the update made to the head unit, it helps explain peoples different opinions. This is
especially true with regard to the standard Nokia 10 speaker system, which many felt were fine,
except for the poor Bass and Screechy highs. The screechy highs could be improved by replacing
the cheap bipolar electrolytic capacitors with same voltage and value polypropylene capacitors,
which gives a much smoother, pleasant and more listenable high frequency sound. This is a
common practice amongst car sound installers. One installer I talked to said he never used
expensive electronic crossovers because the polypropylene caps gave just as good a sound.
The difference between these crossovers is the electronic version gives a cleaner 12dB/octave
rolloff, whereas the capacitor only provides a 6dB/octave rolloff. Professionals believe the higher
rolloff provides a cleaner sound by better separating the frequencies going to the woofer and tweeter.
These capacitors are usually mounted on a support pole on the main woofer. More can be
found on replacing capacitors at http://www.civil.ubc.ca/home/bohnen/adventures1.html

Bass could be improved by adding a subwoofer, driven from the line going to one of the rear
speakers. Possible solutions include bass tubes or enclosed boxes with an 8", 10" or 12" subs,
depending on how much bass you like.

Of course, these were cheap solutions people found to improve the factory sound without
spending big money. If you wanted a really good system, you had to buy a new head unit and
fit high quality speakers, which necessitated a new amplifier because of the factory design was
only compatible with the Nokia Speakers that used a crossover built into the amp.


--------------------------------------------------------------------------------

Factory Head Unit Deficiencies
To: e36m3@Mailing-List.net
Date: Tue, 28 Dec 1999 12:29:45 -0800
From: robert_manger@mastercard.com
Subject: [E36M3] RE:

I am forwarding this I think the list can benefit from this information. I have been
banging my head against the wall looking for the best solution in regards to a
stereo upgrade to my 95 M3. This is the response I received from the horses mouth.

Robert,

Yes, I do know quite a bit about the E36 audio system, as I helped to design it
while working as the Product Development Manager for BMW until recently.
With regards to upgrading your audio system, the weakest link is currently
(and unfortunately) the radio. In your 1995 E36, you have what is called the
C33 platform, identifiable by having weather band feature.

Since then, the unit has been upgraded 2 more times; the C43 and more recently
the CD43. Although the C43 (still a cassette unit) is somewhat better than your C33,
the CD43 is substantially better. The CD43, however, is an in-dash CD player.
The major difference being the output voltage, which better drives the existing
amplifier. All of these units will work in your vehicle with no modifications whatsoever;
the power harness, everything, are direct plug-ins.

What you currently experience is a low voltage output from the C33, which does not
adequately drive (take advantage) of the on-board, external amplifier. Your unit also
has a limiter on the upper frequency range in the FM mode, meaning that when you
play FM, you never hear anything above 9 or 10K. This was because there was
inherent noise from the engine that could not be attenuated, so the radio had to be
attenuated. This hurt sound quality in the upper frequency range (sounds muffled).

I eliminated the limiter altogether on both C43/CD43 platforms for US cars.
Now the Radio drives the amp better and you can enjoy higher frequency output.
These units will work w/o any noise problems in your car.

So basically, what I am suggesting, since you want to retain cosmetic-integration and
don't care for cassette, is to get your hands on the CD43. This will also control
your CD Changer, if you have one.

Now, of coarse, if you are planning a full blown system with amps, etc, then we need
to reconsider my suggestion, since this unit still does not have RCA (line-level)
audio outputs, necessary in driving aftermarket amps (properly).

Let me know what you think

[M3@Apex]

I have the C43 upgraded from C33. It sounds better up high, it's more clear. I don't know how to explain it but if you can get one for cheap, I'd say do it.

[bonoz]

Hi all - do I have the C33 or the C43 head unit? can you tell just by pictures? if I have C33... is it worth upgrading to C43 head unit to improve sound quality?

20221114_211543.jpg

[dinobot]

Hi all - do I have the C33 or the C43 head unit? can you tell just by pictures? if I have C33... is it worth upgrading to C43 head unit to improve sound quality?

20221114_211543.jpg

this is c33 (no RDS button in the lower left corner, no "BMW professional" on the tape door, MODE instead of the note on the button in the middle of + and - buttons above the volume control). C43 will improve sound quality overall, but if your stereo sounds _really_ bad, your problem may be something different... C33 sounds pretty good for the stock stereo, and are fine for cars that are not equipped with hi-fi or harman kardon, I would say.