Notes on a 2012 E92 M3 HiFi Audio Upgrade with mixed OEM and Aftermarket Parts

[Technic]

Originally Posted by VP Electricity

Adhering grills with dynamat doesn't count.

I'm using Gorilla Glue now...

[nelson29]

Very clean install brother!!!!

[taibanl]

Technic, would there be room to but MS-8 UNDER the HD stack? Thats what I want to do (basically exactly where it is in my thread now).

[Technic]

Originally Posted by taibanl

Technic, would there be room to but MS-8 UNDER the HD stack? Thats what I want to do (basically exactly where it is in my thread now).

It may be some space there but the OEM amp bracket must go. There will a problem in plugging the headphones in once it is installed there, though.

[taibanl]

Yes, I have to have my headphone lead plugged into an extension. I should have used a right angle adapter but I was too excited and rushed when I installed. I don't have an OEM bracket, just my crappy DIY bracket, which I think would look better if I took off the top half and replaced with 2xHD

So sounds like it would fit in my case. I thought it would just wondered if there were any hidden gotchas.

[taibanl]

It does look like you had to bend the CD changer door a bit for fitment.

[Technic]

Originally Posted by taibanl

It does look like you had to bend the CD changer door a bit for fitment.

The door closes normally but by cutting the opening (it is for the OEM CD Changer after all) the latch needs to be forced in a little to lock in as the opening tab now bends as it does not have any support anymore.

[taibanl]

Crap. Just realized you have pdx in there. Not jl hd series. Is there an additional 19mm of depth available?

[Technic]

Originally Posted by taibanl

Crap. Just realized you have pdx in there. Not jl hd series. Is there an additional 19mm of depth available?

[taibanl]

Cheers!

[taibanl]

Any thoughts on pdx vs hd that you feel essential to share? My goals are better fitment (like yours) and power balance amongst my channels. I dont need a ton of more spl headroom other than for sq sake

[kaigoss69]

Originally Posted by Technic

Sweet! I thought they would be too deep but I guess my HDs are now going to be moved.

[Technic]

Originally Posted by taibanl

Any thoughts on pdx vs hd that you feel essential to share? My goals are better fitment (like yours) and power balance amongst my channels. I dont need a ton of more spl headroom other than for sq sake

The jury is still out on the HD amps... two years ago I installed a HD900/5 in a HiFi M3 and it was great. Very straight forward install, sounded great without any processor.

Fast forward two years and a coded EPS-HiFi M3 with two HD600/4 (the one in the picture) and no processing showed some changes in sound quality and compatibility that I'm still trying to understand. For example, although the power output should be the same all the way down to 1.5ohms, a 2 ohms load sounds considerably louder than a 4ohms load. Setting their input level to high sounds slightly better than setting it at low, as it should be (it is HiFi as it was with the HD900/5). Installing a MS-8 in between the CIC and the HD amps have shown similar results, so it is not a matter of balanced inputs.

No XD amp have shown issues like that with HiFi outputs.

Something must have changed in these amps that when the customer contacted JL Audio to ask about these issues their "fix" was to install a Cleansweep.

[taibanl]

Thanks. So i guess its safe to say you recommend pdx over hd

[VP Electricity]

After you mentioned this, I asked them if there had been any changes to the design, and Tech Support did not know of any.

[taibanl]

Excuse my ignorance. Why should hi level input sound better? I am aware there is some overlap in the voltage ranges.

[Technic]

Originally Posted by VP Electricity

After you mentioned this, I asked them if there had been any changes to the design, and Tech Support did not know of any.

The only difference that I know of is that the HD900/5 was a Marine version, the HD600/4 (one brand new and the other used) were not.

I asked the customer to swap 600/4 to see if anything changes.

It sounds to me quite decent, until attention is paid to the imbalance in sound level between the front and rears (fronts are the EPS 4ohms, rears are the rear/sides in parallel =2ohms). I have not found such an imbalance with any of my 2 PDX installs with the exact same OEM EPS speakers in the same exact configuration.

[Technic]

Originally Posted by taibanl

Excuse my ignorance. Why should hi level input sound better? I am aware there is some overlap in the voltage ranges.

Sounds better in the sense that the iDrive volume level seems to me and to the customer to correspond better to the level of sound coming from the speakers than setting it to low. Like somehow the 6V balanced inputs are really 6V inputs and needed to be attenuated somehow to match the amps.

For example, the BT phone volume at input set to low is considerably higher than the music level, even when the BT volume is set to the minimum. Then by setting it to high it is pretty much at the same volume level.

Again, this could be an issue with just one particular HD amp. That's what I am trying to find out in this particular case.

[taibanl]

Interesting as i now have two ohm rears. Would be interesting to try a two ohm load on a pair of drivers vs a set of four. Of course theoretically no different

You said you has similar results with the ms-8, so still some degradation in quality even once level matched?

[Technic]

Originally Posted by taibanl

Interesting as i now have two ohm rears. Would be interesting to try a two ohm load on a pair of drivers vs a set of four. Of course theoretically no different

You said you has similar results with the ms-8, so still some degradation in quality even once level matched?

According to the customer, yes. I did not install the MS-8, I only calibrated it once after the install and still it sounded to me that the rears were getting a slightly higher power than the fronts.

[taibanl]

Ok last question (i think). Did you do a pre-cal level match with gain or just set 2.8v sensitivity and press

Im not terribly concerned about the level mismatch as thats an easy fix but if the SQ isnt there id just as soon save $$

[Technic]

Originally Posted by taibanl

Ok last question (i think). Did you do a pre-cal level match with gain or just set 2.8v sensitivity and press

Im not terribly concerned about the level mismatch as thats an easy fix but if the SQ isnt there id just as soon save $$

I tried both and still I could hear higher volume in the back. To be clear, this is not higher as in "damn this is louder!" than the fronts, just enough to notice. And because I already noticed this without the MS-8 then it became obvious that something is not quite right in here.