95 530i Aftermarket Stereo

[saj3n]

I am installing an aftermarket headunit into my 95 530i The model number for the unit is JVC -KD-SHX750 (http://www.cardomain.com/item/JVCKDSHX750). I wanted to know if there is a way that I can still route the audio through the factory amp used to power the 8 speakers in the vehicle. Any Suggestions? I have already purchased the wiring harness for the head unit as well.

[jarome]

i was looking to that same head unit last week. quick question can you adjust the bass/treble level on that? I have an older model and it bugs me that i can't adjust my bass and treble!!

[Anthony (M5 in Calgary)]

I am installing an aftermarket headunit into my 95 530i The model number for the unit is JVC -KD-SHX750 (http://www.cardomain.com/item/JVCKDSHX750). I wanted to know if there is a way that I can still route the audio through the factory amp used to power the 8 speakers in the vehicle. Any Suggestions? I have already purchased the wiring harness for the head unit as well.


...then open the factory booster amp. Take off the board attached to the top heatsink and feed the new HU wires to the exposed pins. You'll have the factory wiring all working in your favour, plus the crossover will send the correct frequencies to the relevant speakers.

This shot shows the amp with the cover off (later model with SMT parts):

http://img.photobucket.com/albums/v11/interalian/stereo%20stuff/06insideamp.jpg

This shot shows where to attach the wires (early model with through-hole parts). The white wire is the remote switch lead for another amp:

http://img.photobucket.com/albums/v11/interalian/stereo%20stuff/535ampwithheatsink.jpg

Here's a close-up of which pins to use. Polarity is --/++ all the way across. All of the --/++ were separate on my 2 cars, not connected to chassis:

http://img.photobucket.com/albums/v11/interalian/stereo%20stuff/535ampwirestospeakers.jpg

HTH,
Anthony

[TheDuke]

I just put in JVC KD-AR5000 (http://www.cardomain.com/item/JVCKDAR5000). Sounds way better than stock, even without an amp. Right now its holding by the duck tape and a crappy bracket that I've found in my basement. Still need to connect the antenna, but so far I'm amazed with the difference in quality. By the way anyone wants to buy stock cd changer. I believe it's the Pioneer one. Works great. If anyone is interested in it email me at TheDuke@iname.com

[saj3n]

I just put in JVC KD-AR5000 (http://www.cardomain.com/item/JVCKDAR5000). Sounds way better than stock, even without an amp. Right now its holding by the duck tape and a crappy bracket that I've found in my basement. Still need to connect the antenna, but so far I'm amazed with the difference in quality. By the way anyone wants to buy stock cd changer. I believe it's the Pioneer one. Works great. If anyone is interested in it email me at TheDuke@iname.com

Are you able to use all of the speakers in the vehicle. Because I know that when I took my first E34 in before I was confident with installing stereos myself, they bypassed the factory amp, but I was not getting power to the mid ranges on the dash, nor to the tweeters in the back or front, because the reciever only has 4 channels out. I know that if I wired through the factory amplifier, it would use the built in crossovers as well for the tweeters. Unles, you have found a way for the audio to play out of all 8 speakers, without harmonic distortion from the tweeters, and mid's when hitting lower notes....

[saj3n]

i was looking to that same head unit last week. quick question can you adjust the bass/treble level on that? I have an older model and it bugs me that i can't adjust my bass and treble!!

Yes you can. This one, as well as most of the JVC units now, have the built in equalizer that you can use to manually adjust each frequency that the stereo outputs so it is even more effective when attempting to maintain that perfect sound.

[saj3n]

...then open the factory booster amp. Take off the board attached to the top heatsink and feed the new HU wires to the exposed pins. You'll have the factory wiring all working in your favour, plus the crossover will send the correct frequencies to the relevant speakers.

This shot shows the amp with the cover off (later model with SMT parts):

http://img.photobucket.com/albums/v11/interalian/stereo%20stuff/06insideamp.jpg

This shot shows where to attach the wires (early model with through-hole parts). The white wire is the remote switch lead for another amp:

http://img.photobucket.com/albums/v11/interalian/stereo%20stuff/535ampwithheatsink.jpg

Here's a close-up of which pins to use. Polarity is --/++ all the way across. All of the --/++ were separate on my 2 cars, not connected to chassis:

http://img.photobucket.com/albums/v11/interalian/stereo%20stuff/535ampwirestospeakers.jpg

HTH,
Anthony

Thanks Anthony,

I have yet to try this, I do have a question for you though. I was speaking with the folks at crutchfield and they informed me that it would be possible to wire directly to the amplifier using the harness, and this device PAC OEM-2 (http://www.crutchfield.com/S-4kLW2PmTEO3/cgi-bin/ProdView.asp?i=127OEM2&search=PAC+OEM%2D2). What are your ideas regarding this?

[Anthony (M5 in Calgary)]

Thanks Anthony,

I have yet to try this, I do have a question for you though. I was speaking with the folks at crutchfield and they informed me that it would be possible to wire directly to the amplifier using the harness, and this device PAC OEM-2 (http://www.crutchfield.com/S-4kLW2PmTEO3/cgi-bin/ProdView.asp?i=127OEM2&search=PAC+OEM%2D2). What are your ideas regarding this?

The adapter would take the high power output from the JVC to drive the low power input to the factory amp which is only 10W x 4. The factory HU has about 4W/ch out. The JVC amp you bought says it has 52W x 4, more than enough to blow the $hit out of your factory speakers. Just run 4 pairs of 18-16ga speaker wire from the HU to the trunk then follow the pix. If anything is unclear post back.

This will allow the exact use of the factory crossover without having to pull any of the wiring directly to speakers. Run the speaker wire across (behind) the driver's kneepad then down the kick, and along the driver's side rocker panel (you'll have to remove the rocker trims then pull the carpet away a bit). Push the wires way down into the padding next to the rocker panel. There's a nice big grommet in the rear seat panel which exits at trunk floor level behind the trunk liner panel. The factory amp is on the driver's rear behind the wheel.

You won't be able to drive the factory speakers very hard as they're only rated about 30W but they sound pretty good.

I'm using all of the factory speakers but using a 5 channel amp and only driving 80Hz and above to them. The system is supplemented by a small sub. You can see parts of my system on www.bmwe34.net under the stereo section.

HTH,
Anthony

[grave77]

if ur using a 4 output stereo u will need to cross the 2 commons together ... example: front left and rear left has 1 common sometimes they provide 4 wires so u need to cross the 2 commons to the amplifier input common, the same for the right. the amplifer used in BMW has low impedence input so u dont need to worry about the distortion unless the stereo u bought has more power than the BMW amp.
BMW amp uses the TDA2005 IC ... its a 10W X 2 or 18W BTL ( Mono Bridged ) I remember that it had 4 ICs inside ... with a passive crossover for the tweeters ... so this is powerfull enough ... some stereos has power upto 25W X 4 but that's not so real. BMW amp is close the the max power that can be delivered from 12V power supply. if u want more then u need to install an Amp with PWM power supply and that would be a different stroy.
if u had a problem I can draw u a simple wiring schematic for ur system ... I have the same setup with 2 more high power amplifers.

[Mobius]

HTH,
AnthonyWell ****, of course that helps. That's damn good info.

It's coming about two years too late for me, goddamnit. :)

For the record, I'm running a pair of passive crossovers off a friend's blown Infinity Kappa Perfects to drive the front tweeters, and it sounds lovely. Had I known this, it would've been (relatively) simple to get all speakers working at the actual, correct crossover.. Damn.

Genius, Anthony. Genius.

[Anthony (M5 in Calgary)]

if ur using a 4 output stereo u will need to cross the 2 commons together ... example: front left and rear left has 1 common sometimes they provide 4 wires so u need to cross the 2 commons to the amplifier input common, the same for the right. the amplifer used in BMW has low impedence input so u dont need to worry about the distortion unless the stereo u bought has more power than the BMW amp.
BMW amp uses the TDA2005 IC ... its a 10W X 2 or 18W BTL ( Mono Bridged ) I remember that it had 4 ICs inside ... with a passive crossover for the tweeters ... so this is powerfull enough ... some stereos has power upto 25W X 4 but that's not so real. BMW amp is close the the max power that can be delivered from 12V power supply. if u want more then u need to install an Amp with PWM power supply and that would be a different stroy.
if u had a problem I can draw u a simple wiring schematic for ur system ... I have the same setup with 2 more high power amplifers.

The factory wiring between the HU and the amp may well have common grounds. I just ditched the whole problem by running leads directly from the new HU to the inputs to the factory crossover, amp block removed. All of the outputs from the crossover to the speakers are separate and isolated from ground.

Feeding the low impedance inputs to the factory amp from a higher power HU completely defeats the purpose of any HU upgrade unless all you want is the added technical functionality of the newer unit (MP3, CD, whatever).

The TDA 2005s in the factory amp may well be configured BTL and give a theoretical 18W/ch but they still sound like crap. Having gone through numerous configurations all keeping the factory speakers, my final config sounds by far the best of all of them.

BTW, modern audio amplifiers achieve high output power by using switch mode power supplies to increase the 12V available in the car to a +/- 35 or more giving 70V+ swing for the amp. Also, class D amps can drive very high outputs using low voltage. I've seen 20W from a 3.3V supply.

HTH,
Anthony

[Mobius]

Also, class D amps can drive very high outputs using low voltage. I've seen 20W from a 3.3V supply.So, what are the drawbacks of a Class D amp?

[TheDuke]

Are you able to use all of the speakers in the vehicle. Because I know that ....
I used harnesses to connect the radio, didn’t have time to play around with wire matching (or too lazy;). All speakers work. It's true the radio has enough power to blow the shi&$ out of factory speakers.

[grave77]

thats true.. I suggested my way for quick installation, I'm cosidering ur methode for installing a DSP rack. I have 4 outputs and I need a hi-imp. inputs ... TDA2005 has been there for around 20 years or more ... there are new versions now of TDA power ICs ... I have 4 or 5 Datasheets of them if ur interested. Class D is the ultimate power amplifiers power wise, but 20W with 3.3v is impossible ... P = (V^2) / R so if the speakers were 2 Ohms and the amp slews to max supply voltage then the output power will be approximatly 16/2 = 8 Watts RMS P.M.P.O output is crap ... sometimes they mutiply the RMS by 35 to write down fictional power outputs. ( pocket radio delivers 1W RMS max,on the front written 35Watts.

[Anthony (M5 in Calgary)]

So, what are the drawbacks of a Class D amp?

None. Just new technology, the output looks nothing like the old fashioned analog signal you may have ever seen on an oscilloscope. Very efficient.

Anthony

[Anthony (M5 in Calgary)]

thats true.. I suggested my way for quick installation, I'm cosidering ur methode for installing a DSP rack. I have 4 outputs and I need a hi-imp. inputs ... TDA2005 has been there for around 20 years or more ... there are new versions now of TDA power ICs ... I have 4 or 5 Datasheets of them if ur interested. Class D is the ultimate power amplifiers power wise, but 20W with 3.3v is impossible ... P = (V^2) / R so if the speakers were 2 Ohms and the amp slews to max supply voltage then the output power will be approximatly 16/2 = 8 Watts RMS P.M.P.O output is crap ... sometimes they mutiply the RMS by 35 to write down fictional power outputs. ( pocket radio delivers 1W RMS max,on the front written 35Watts.


Amplifier hype aside, the best way to drive the factory speakers is by bypassing the interface between the factory HU and the factory amp then just connecting the inputs to the crossover terminals.

Combined with a 5 channel amp driving only 80Hz and up to the factory speakers and adding a sub the sound is as good as you'll get with high end systems in new cars. The factory 5.25" mids can easily handle high SPLs once the bass elements are removed.

HTH,
Anthony

[grave77]

thats true ... I'm using them as midrange now ... I just wonder if there is a high impedence input ready made for the amp or not. I didn't really check it closly yet. I would be glad if u know the pins

[Mobius]

None. Just new technology, the output looks nothing like the old fashioned analog signal you may have ever seen on an oscilloscope. Very efficient.Ah. I just keep hearing about how great Class D amps are; I figured there had to be some downside.

[saj3n]

The factory wiring between the HU and the amp may well have common grounds. I just ditched the whole problem by running leads directly from the new HU to the inputs to the factory crossover, amp block removed. All of the outputs from the crossover to the speakers are separate and isolated from ground.

Feeding the low impedance inputs to the factory amp from a higher power HU completely defeats the purpose of any HU upgrade unless all you want is the added technical functionality of the newer unit (MP3, CD, whatever).

The TDA 2005s in the factory amp may well be configured BTL and give a theoretical 18W/ch but they still sound like crap. Having gone through numerous configurations all keeping the factory speakers, my final config sounds by far the best of all of them.

BTW, modern audio amplifiers achieve high output power by using switch mode power supplies to increase the 12V available in the car to a +/- 35 or more giving 70V+ swing for the amp. Also, class D amps can drive very high outputs using low voltage. I've seen 20W from a 3.3V supply.

HTH,
Anthony


Thanks for all the help Anthony, and everyone else too! Very useful information. My Wire harness arrives today and I will be doing the installation tonight. I will post updates as soon as I finish the work.

Thanks again!

[Anthony (M5 in Calgary)]

thats true ... I'm using them as midrange now ... I just wonder if there is a high impedence input ready made for the amp or not. I didn't really check it closly yet. I would be glad if u know the pins

...and drive the OE booster amp? There's no such input on that amp but I bet it would be no trick to re-jig the input sensitivity of the TDA2005 circuit though. Usually low Z amp inputs just use a moderately high power (say 1-2W rated resistors) load around 70 ohms to provide stability for the amp that's driving. The circuit should be easy to mod but I suspect the load resistors are on the main portion of the amp board, not on the power module.

I suspect BMW's reason for going the booster method was to allow for a base HU that would work for base applications and added the booster for "higher market" cars. Plus, speaker level signals are more immune to electrical noise.

HTH,
Anthony

[saj3n]

I used harnesses to connect the radio, didn’t have time to play around with wire matching (or too lazy;). All speakers work. It's true the radio has enough power to blow the shi&$ out of factory speakers.

Ok, Installed! I just used the harness, like TheDuke, and connected it directly to the back of my stereo and then secured it with the bmw's factory wiring. After that was done, about 15 minutes worth of work, the radio plays nicely through all speakers. Now there is just a problem with the stereo itself not playing audio when I play mp3 files from a cd or sd card.... I have to check on that after work today... :p

[saj3n]

Ok, Installed! I just used the harness, like TheDuke, and connected it directly to the back of my stereo and then secured it with the bmw's factory wiring. After that was done, about 15 minutes worth of work, the radio plays nicely through all speakers. Now there is just a problem with the stereo itself not playing audio when I play mp3 files from a cd or sd card.... I have to check on that after work today... :p

So I called JVC regarding this probleme and here are the transcripts of the call:

"Can I have you name and number..."

"What is the unit doing?"

"Have you tried resetting it"

"It's defective, send in for repair"

-the quickest service call ever.

And so I call the repair shop, and they tell me that it would take 2 and a half weeks for me to get my stereo back.... So this one is going to be returned to the store... Thanks guys for all your help! Hopefully I can reap some of the benefits of my work soon!