E34 stereo question

[SKB]

I had a 1990 E34 525i with a stock stereo and cd unit in the trunk. It sounded great.

I then got a 1993 E34 525i with no cd unit and it sounds pretty bad. no headroom and seems to distort and have a fuzzy sound just over half way.

I replaced the Head Unit with an Alpine CD player and it still sounds exactly the same. I can't figure out if its the speakers or the factory amp or what.
Anyone else run into this?? Any suggestions? thanks.

SKB

[632 Regal]

did you check to see if anyone messed with the factory wiring? Maybe someone bypassed the amp and used something else at some time or another and threw the stock stuff back in without hooking up the amp?

[SKB]

did you check to see if anyone messed with the factory wiring? Maybe someone bypassed the amp and used something else at some time or another and threw the stock stuff back in without hooking up the amp?

Yes I repaced the factory wireing with a wireing harness. I soldered all the connections myself as per the wireing diagram. F & R , Left and right chn's all work fine. Fades OK. However I wondered about the amp too. Is that located under the rear seat drivers side?? Does seem like the speakers are not getting enough power.

[talltorontoguy]

The factory amp is usually located on the drivers side of the trunk behind the lining. (between the corner of the car and the wheel well).

If you haven't hooked up the factory amp, the head unit (stock or not) will likely not have enough power to drive the speakers cleanly. Hence the distortion.

You'll need a wiring diagram for the factory amp inputs and outputs... I cannot remember the details but know it was a little unconventional. Many people prefer to replace the factory amp with a more current one.

[bjl4776]

did you get a converter box such as the Pac OEM 2 to convert the signal of the aftermarket headunit to a common ground signal that the factory amp needs. When I installed my headunit it was really distorted and then I talked to the ctrutchfield people and they said that I needed that, so i installed that in and sounds great now.

[Jon K]

did you get a converter box such as the Pac OEM 2 to convert the signal of the aftermarket headunit to a common ground signal that the factory amp needs. When I installed my headunit it was really distorted and then I talked to the ctrutchfield people and they said that I needed that, so i installed that in and sounds great now.

I have a PAC OEM2 for sale if anyone is interested make an offer

[SKB]

did you get a converter box such as the Pac OEM 2 to convert the signal of the aftermarket headunit to a common ground signal that the factory amp needs. When I installed my headunit it was really distorted and then I talked to the ctrutchfield people and they said that I needed that, so i installed that in and sounds great now.

Good point and yes I did get the Pac OEM 2 from Crutchfield and have it turned up about 3/4 on the 4 small volume pot's. It does now sound like the OEM amp may not be hooked up..or may be sick. I will check that (or maybe just replace it) now I know where it is. Thanks folks this helps a bunch!!

SKB

[Jon K]

Good point and yes I did get the Pac OEM 2 from Crutchfield and have it turned up about 3/4 on the 4 small volume pot's. It does now sound like the OEM amp may not be hooked up..or may be sick. I will check that (or maybe just replace it) now I know where it is. Thanks folks this helps a bunch!!

SKB



If you need an OEM amp, let me know. I have one laying around in good working condition.

[SKB]

If you need an OEM amp, let me know. I have one laying around in good working condition.


thanks Jon

I'm going to check it out in the next couple days..I very well may be in touch.
SKB

[SKB]

thanks Jon

I'm going to check it out in the next couple days..I very well may be in touch.
SKB


OK I found the amp and checked it out. It seems to be OK. I actually pulled the fuse and tried it and nothing. Then put the fuse back in and it played as normal. I'm thinking now this is just normal operation. I have the Alpine HU going into the PAC OEM-2. All speakers work fine. The max vol. on the HU is 35. It starts to distort at about 26-27 with CD or radio and Loudness off.

Again I have a '93 525I, But my '90 525I sounded very good and crunchy and I could just about max it out with no distortion. Does anyone know if the '90 525I used a different OEM amp than the '93 525I? Jon k. what year is your OEM amp from?

[saj3n]

OK I found the amp and checked it out. It seems to be OK. I actually pulled the fuse and tried it and nothing. Then put the fuse back in and it played as normal. I'm thinking now this is just normal operation. I have the Alpine HU going into the PAC OEM-2. All speakers work fine. The max vol. on the HU is 35. It starts to distort at about 26-27 with CD or radio and Loudness off.

Again I have a '93 525I, But my '90 525I sounded very good and crunchy and I could just about max it out with no distortion. Does anyone know if the '90 525I used a different OEM amp than the '93 525I? Jon k. what year is your OEM amp from?

I had a couple of similar questions when installing my stereo and got great support. Have you tried not using the PAC OEM-2, I purchased for my installtion and did not use, and the stereo sounds nice! If you have a wire harness coming from your apline unit directly into the factory's wiring device, you should experience an increase in sound quality.

Information provided by Anthony regarding the PAC OEM-2 and my reciever, very helpful!


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

[Arxon]

I just replace the stock radio with a Pioneer deh 77md and found great difference in the quality, now I'm planning to install an amp and speakers for better performance of my stereo

[Kalevera]

This might be really uh...a stupid question, in fact one that might have already been addressed, but I'll fire away --

Is the HU using RCA outs or the line level ones? The reason I ask is, if the alpine HU puts out more than 5w (or whatever the stock one does) at the line levels, it's going to be sending a messed up signal to the amp, and the amp's going to distort it at any substantial volume.

best, whit

[SKB]

This might be really uh...a stupid question, in fact one that might have already been addressed, but I'll fire away --

Is the HU using RCA outs or the line level ones? The reason I ask is, if the alpine HU puts out more than 5w (or whatever the stock one does) at the line levels, it's going to be sending a messed up signal to the amp, and the amp's going to distort it at any substantial volume.

best, whit

Whit,

No I'm not using the RCA outs on the HU. I'm using the wiring harness and going into the PAC OEM2 because of the common ground system on the 525i.
I could remove the OEM2 and try tying all the negative(grounds) together but that seems cheezy to me. My Alpine HU is 18watts RMS X 4 going into the OEM amp which is 10W X 4. So this makes 28watts x 4 going into the OEM stock speakers. I just read, I think, the stock speakers are only rated for 30 watts. So maybe this is just normal and I'm really pushing the stock speakers to the max, thus not clean crunchy sound at higher SPL levels. Does this make sence?

I'm looking at adding a 4 channel amp and new speakers and speaker wire if I really want better sound. This would get rid of the common ground system. Also what kind of speakers have people used for the rear deck I know they are 5.25's but only 1.75 in depth. The front would be easy, just use component speakers.

[Anthony (M5 in Calgary)]

Whit,

No I'm not using the RCA outs on the HU. I'm using the wiring harness and going into the PAC OEM2 because of the common ground system on the 525i.
I could remove the OEM2 and try tying all the negative(grounds) together but that seems cheezy to me. My Alpine HU is 18watts RMS X 4 going into the OEM amp which is 10W X 4. So this makes 28watts x 4 going into the OEM stock speakers. I just read, I think, the stock speakers are only rated for 30 watts. So maybe this is just normal and I'm really pushing the stock speakers to the max, thus not clean crunchy sound at higher SPL levels. Does this make sence?

I'm looking at adding a 4 channel amp and new speakers and speaker wire if I really want better sound. This would get rid of the common ground system. Also what kind of speakers have people used for the rear deck I know they are 5.25's but only 1.75 in depth. The front would be easy, just use component speakers.

When you drive the OE amp with high level (speaker) leads, the audio is just "sampled" at the input to the OE amp. All you're getting is the OE amp's output.

The rear speakers don't add much

Try it my way: http://www.bimmer.info/forum/showthread.php?t=11484

HTH,
Anthony

Edit: while my M5 is down for service I'm driving my old '90 535 with full factory stereo. It is fully capable of blasting the speakers but cannot make any decent SPLs. Get rid of the bass notes to the factory speakers (install a sub) and they rock.

[MBXB]

Have you physically inspected all the speakers for cracks, etc?

[SKB]

Yes I have looked at the rear deck speakers only and they don't have any cracks but do have rubber surrounds and look OK.

I think I'm simply in a normal operational mode with this system and it's just the way it is. So I think, down the road, I'm just going to repalce the OEM speakers and get a 4 channel amp. My questionis for folks who have already done this...

I want to put component speakers up front. I know I can mount the woovers down in the kick pannels, but where are folks mounting the tweeters??
In the pilliars, where the tweeters are now or in the front L + R top dash location where this Midrange is now? Thanks for any info and further advice.
SKB

PS My Alpine HU does have RCA outs for Front and Rear speakers so all I need to do is find and amp that will accept the RCA in's. Plus I think installing the amp in the trunk will be easy with the battery under the back seat.