heinzboehmer's 2002 Topaz 6MT Coupe

[heinzboehmer]

Oh man, that's a serious crash. Glad you weren't hurt!

[heinzboehmer]

Quick bit of maintenance.

Harman Kardon amp in the trunk was acting up. When I parked the car in the sun, the amp would overheat and no sound would come from the speakers. So, I took it apart to clean it and replace the thermal paste:




That's what the unit looked like straight from the car. I was honestly very surprised at how clean it was. I was expecting it to be filled with dust, but nope.

23 year old thermal paste was definitely not doing its job anymore though:




Cleaned the old stuff off, replaced with new and done. Hopefully this fixes my issue.

Also, I have to say that I really like how this thing is designed. The housing is extruded aluminum, so the board slides in from either side. The long silver strip then clamps the amps to the housing and acts as more area for heat to dissipate. The part I thought was most clever is that the board isn't directly fastened to the housing. Instead, it's held in place by the front daughter board (with the harness connector), the heat sink clamp and these rubber bands that friction fit into the housing:




Good stuff, gonna have to steal that rubber band idea for some future design of my own.

The one downside of this design is that assembly is a bit fuzzy, as you can smear the thermal paste everywhere if you're not careful. But overall, thumbs up from me.

Also, keeping with the audio theme, just sent my CD53 out to Baris - Carphonics for amp upgrades. Excited to get the upgraded unit back and installed. I didn't want to be left with no music, so I ran over to the junkyard and grabbed another CD53, which ended up being in way worse shape than my own. Swapped faceplates before sending mine out, as I was definitely not going to be able to stand the shitty junkyard one.

But of course, nothing ever goes smoothly, and it turns out that the display backlight driver is broken on the junkyard HW. At first, I thought I had messed up the ribbon cable/faceplate when swapping, but I swapped back (and forth) and the issue stayed with the junkyard HW. So now I can't really see what the display says unless in fairly direct sunlight. Oh well, at least the audio seems to work fine. One more reason to be excited about getting my own unit back!

[heinzboehmer]

Drove the car around today. Amusingly, the junkyard radio sounds significantly better than what I sent out to upgrade, regardless of the worse aesthetic condition and broken display driver. Both were manufactured in 2004, so I don't think it actually matters which one gets the upgrade.

It'll be nice to have a decent reference point to compare the upgraded unit against, though. Pretty much anything is gonna sound better than the buzzy/static-y unit that was in there before (as proven by the junkyard radio).

Edit: I just realized I changed two variable at once, duh. I guess the only thing I can say for sure is that the system sounds better as a whole. Can't really attribute to the junkyard radio, as the HK amp could have also been playing a role.

[Obioban]

I am, generally, a sucker for passively cooled electronic components. If you can skip having a fan, you have my attention.

No moving parts or dust accumulation ftw.

[heinzboehmer]

I am, generally, a sucker for passively cooled electronic components. If you can skip having a fan, you have my attention.

No moving parts or dust accumulation ftw.

+1. Love the reliability of having no moving parts.

[D-O]

What are the benefits of amp upgrades in the head unit?

[Obioban]

What are the benefits of amp upgrades in the head unit?

Sound quality.

[heinzboehmer]

What are the benefits of amp upgrades in the head unit?

Yep, mostly sound quality.

Although Baris does advertise 50 Wrms per channel, so might be possible to drive the speakers directly. The weight savings potential is there, but redoing the entire harness sounds like a lot of (boring) work. My car's weight distribution is also a bit skewed towards the front right now (it's at something like 51:49 with me in it), so not exactly keen on making it even worse by removing the HK amp in the trunk. Maybe at some point in the future I'll revisit the idea, but for now, I just want the sound coming out of the speakers to stop being static-y

IObioban you did something along those lines in your car, right? Do you remember what the total weight savings were? Did you also get before/after weight distribution measurements?

[Obioban]

Yep, mostly sound quality.

Although Baris does advertise 50 Wrms per channel, so might be possible to drive the speakers directly. The weight savings potential is there, but redoing the entire harness sounds like a lot of (boring) work. My car's weight distribution is also a bit skewed towards the front right now (it's at something like 51:49 with me in it), so not exactly keen on making it even worse by removing the HK amp in the trunk. Maybe at some point in the future I'll revisit the idea, but for now, I just want the sound coming out of the speakers to stop being static-y

IObioban you did something along those lines in your car, right? Do you remember what the total weight savings were? Did you also get before/after weight distribution measurements?

I did do that, yes.

I didn't do a before/after, but I did weight the pile of all the stuff I took out (battery cable to the trunk, entire stereo harness, trunk module scaffolding that holds the modules, all the stock modules (amp, bluetooth, DVD drive, MKIV display, etc), all the speakers other than the door speakers (which are now directly powered by the heat unit)-- and it was 46 lbs.

Can confirm two speakers plugged directly to the head unit is a sound quality downgrade- but I just listen to podcasts 99.9% of the time, so.... don't care.

[heinzboehmer]

I did do that, yes.

I didn't do a before/after, but I did weight the pile of all the stuff I took out (battery cable to the trunk, entire stereo harness, trunk module scaffolding that holds the modules, all the stock modules (amp, bluetooth, DVD drive, MKIV display, etc), all the speakers other than the door speakers (which are now directly powered by the heat unit)-- and it was 46 lbs.

Can confirm two speakers plugged directly to the head unit is a sound quality downgrade- but I just listen to podcasts 99.9% of the time, so.... don't care.

Oh! Didn't realize you were only running on two speakers. In my case, if the radio is on, it's playing music, so two speakers probably won't cut for me. But, even half of the weight you saved is significant...

I guess project added to the ever growing list. Or, really, two projects (ordered by priority):

1. Shift weight balance rearwards by losing weight from the front or shifting components backwards (the front bracing should help with this as I want to remake the firewall plug and cabin air filter housing in CF)
2. Remove HK amp and redo audio harness to drive speakers directly from headunit

The only other thing to consider is sound quality. I bet it'll be fine in my semi-track-car'd out car, but I would like to confirm before permanently ripping things out. Simple patch plug connected to the HK amp harness connector should be good enough for the initial evaluation. Maybe I'll start there once I get my CD53 back.

[YoitsTmac]

I'm working on retrofitting iDrive 6 if you're not in a rush. Closing out a dev project and then I'll have more time for it. You'll have to be comfortable with a bit of wiring depending on the level of integration you want, but nothing too crazy

[heinzboehmer]

I'm working on retrofitting iDrive 6 if you're not in a rush. Closing out a dev project and then I'll have more time for it. You'll have to be comfortable with a bit of wiring depending on the level of integration you want, but nothing too crazy

Oh cool! You should definitely post about that on here once you get it working, sounds like an interesting project.

Personally, I want to keep my M3 screen-free, so I think I'll stick with the CD53. If I ever need more, I'll gut the headunit and just use it as a control interface for a modern amp.

[0-60motorsports]

I'm working on retrofitting iDrive 6 if you're not in a rush. Closing out a dev project and then I'll have more time for it. You'll have to be comfortable with a bit of wiring depending on the level of integration you want, but nothing too crazy

Would love to upgrade from the shitty mk4

[Obioban]

Would love to upgrade from the shitty mk4

Ha. I vastly prefer MK4 to any of the variants of iDrive I've owned (including 6, which I had in my i3). Adding wireless carplay to it would make me never want to change it.

Just because it amuses me every time, the iDrive in my current M5 (e60) racing the MKIV in my old (and vastly better car overall) e39 M5: