E30 Audio Overhaul - My Project Details

[bmwman91]

Wait, all this work and you're keeping the speakers in the kick panel? Come on man go with something in the door.

Haha, absolutely not! I want this as stock looking as possible. Break-ins are prevalent right now, and I don't want to deal with that.

As mentioned, most (but not all) home audio drivers are 8ohms vs 4/2ohm and lower sensitivity. Other than that, you can still find some nice drivers for the money but I would never install my scanspeaks or vifas/seas/peerless in a car... they belong in a nicer home environment for longer / better use. imho .

Agreed, I wouldn't put a $300 driver in a car. It is pretty easy to find 4 Ohm versions of a lot of drivers though.

[StereoInstaller1]

Wait, all this work and you're keeping the speakers in the kick panel? Come on man go with something in the door.

Kick panels in an E30 just suck. I did some decent 6.5's in the stock spot, but they have to be a neo magnet. That is why I don't fuck around with either location...but on the other hand, E34 kickpanels kick ass!





No chance in hell for any action like that in the E30 though. The frame of the door protrudes into the tiny little 5.25" stock spot...I wish you all the luck in the damn world getting something decent going on!

[5Toes]

Is that pic the 6.5's in stock E30 kickpanels?

[StereoInstaller1]

Kick panels in an E30 just suck. I did some decent 6.5's in the stock spot, but they have to be a neo magnet. That is why I don't fuck around with either location...but on the other hand, E34 kickpanels kick ass!


No chance in hell for any action like that in the E30 though. The frame of the door protrudes into the tiny little 5.25" stock spot...I wish you all the luck in the damn world getting something decent going on!

[bryant.cw]

Trust us, the kickpanel location is a JOKE for sound quality. I put in some high quality speakers and have them biamped. They sound like straight ass. I will do 6.5"s in the doors, and seal up the doors with dynamat type material. Done properly they will not look crazy aftermarket or valuable to steal. I have no idea how you are going to shoehorn that 6" in there.

There is a reason not a single person has come on here and had a good idea or recommendation for you to go with in the stock location; there isn't one.

Sorry if I sound harsh, just don't want you to waste your time and money.

[bmwman91]

Trust us, the kickpanel location is a JOKE for sound quality. I put in some high quality speakers and have them biamped. They sound like straight ass. I will do 6.5"s in the doors, and seal up the doors with dynamat type material. Done properly they will not look crazy aftermarket or valuable to steal. I have no idea how you are going to shoehorn that 6" in there.

There is a reason not a single person has come on here and had a good idea or recommendation for you to go with in the stock location; there isn't one.

Sorry if I sound harsh, just don't want you to waste your time and money.

No worries, I always appreciate input.

I'll stick them down there & see how it turns out. If it really sounds awful then I will look into moving to the doors. Moisture is just so much more of an issue there, though. That, and I cannot use a deep woofer since it would block the window from moving and I do not want to use spacers since they scream "aftermarket stuff." I am really sort of hell-bent on retaining the most stock look possible. Trust me, people will steal anything. I lost a beaten-up 20 year old steel frame mountain bike that was U-locked to my staircase (they cut it), and that presumably took longer to get through than a car window! That must have taken an hour to cut lol...I hope they get a ruptured bicep's tendon.

The kick panels are easy to get 6.5" speakers into...there are some 6.75" ones there now. It just takes some patience & tin snips.

[Dirtboy]

You can run either the + or - output of each channel to the 6XS. Read my breakdown of the CD43 here:

http://www.r3vlimited.com/board/showthread.php?t=170952

As long as you run one of those (it really doesn't matter which) to the + terminal on an RCA plug and connect the - terminal to the chassis ground, you are fine. One thing you can do to improve on that is to use the Audio Control level converter. that will accept the differential signal & then feed a ground-referenced signal to the 6XS. The advantage there is that you can run the diff signal all the way to the trunk which will greatly help to reduce noise if that is an issue, and then run a minimal distance of unbalanced signal from the converter to the 6XS. I am thinking that it won't be necessary, but I will do that if I get lots of alternator or ignition noise somehow.

So what would you suggest I use to hook up a Kicker KQ30 eq from a C43 deck? Any highly recommended LOC's?

[bmwman91]

So what would you suggest I use to hook up a Kicker KQ30 eq from a C43 deck? Any highly recommended LOC's?

I have no idea, it depends on the hardware. Unless it specifically states that it (EQ) can accept line-level signals, you shouldn't connect it that way. You can try contacting Kicker to find out what the maximum input voltage is, and if the inputs are grounded or differential. If you have the EQ unit, you can use a DMM to test the impedance between the - input terminal & the ground terminal on it. If the resistance is almost nothing, then you definitely don't want to run both HU outputs to it. The max output from a head unit is probably going to be equal to the battery voltage.

The only LOC I know of is the LC6i, and I haven't used it.

[StereoInstaller1]

That Kicker can accept a 9VRMS input, you will be fine.

Turn the input gain all the way down when you start tuning.

[bmwman91]

Today's update:

I finished modifying the tweeters to fit in the pods. It was pretty easy...making the fixture was more work than modding the tweeters lol.

Since putting ferrofluid-filled tweeters into a lathe & spinning them really fast seemed like a bad idea, I decided to make a fixture that would hold them on a rotary table. There the cuts could be made with a mill.


The tweeter is held onto the fixture with an M4x0.7 x 16 machine screw. There is a boss on the back that fits tightly into a bore in the rotary table, thus making it easy to center it on there. I made the jig from a D2.5" 6061 aluminum bar scrap.




The milling operation was simple. I chopped off the flange and knocked a little material off of the front to a diameter of 38mm so it would fit nicely into the existing tweeter pod hole. Obviously, I didn't want to cut too much off or else the nice diffuser would fall off, and probably end up destroying the dome in the process. I held a shop-vac hose next to the cutter during the process to keep chips out of the thing.


Here they are, all chopped up.


Fitted into the pod...


There is about 2mm of clearance between the diffuser & the grill...perfect! I stuck them in the car and there is like 10mm of extra room behind them. That is good, because I would have been pissed if they weren't going to fit!

[StereoInstaller1]

That looks perfect!

Gonna sound great!

[pegase747]

Amazing installation ! and using the CD43, that will be killer install, looking OEM, Love it ! My dream.

Pierre

[pegase747]

Can you adjust crossovers with the 6XS ??

Cheers Pierre

[Mless5]

IIRC, you change chips to change xo point in AC products.

[bmwman91]

I have almost all of the parts & hardware now. The supplier of all the marine-grade splices & terminals messed up & sent me fewer connectors than I ordered, so I need to wait for the rest.

Anyway, the plan for the weekend is mainly to mount the amplifier & XO, and to build the sub baffle. I won't be tearing the interior out until I am 100% prepared to do the electrical stuff & knock it all out.

In the spirit of the build, I will be going overboard with the mounting scheme on the electronics. It will be a vibration-isolated setup using some nice neoprene rubber foam blocks. Electronics & vibration don't mix well in the long-run, so I want to make sure everything lives a long & happy life.

I also got the tweeters done & installed. I had to bend some metal tabs in the door to grab them better, and get creative with a file to get them in right, but they look good now. I still need to find some 1/8" open-celled foam to put under the tweeter grills so that they don't look special to thieves.

Yeah, it is not super clean, but nobody sees it. You can see where I had to get the file out so that the plastic body of the tweeter could clear the door frame.


This is the amp. It is big as hell and mounting it will be a chore. Overall, I am totally underwhelmed by it. For $380 it is almost a joke considering the quality of home-amplifiers you can get for $200. The mounting flanges are plastic, the adjustment pots aren't totally straight and one of the warranty stickers was slightly cracked. I was bench-testing it to set the gain earlier, and it is sort of shitty. Ch1 & 2 share a gain potentiometer, and there is a ~12% difference between the channels for any given gain setting (that's a "feature" right, since the right speakers are further away from me?). They should have made adjustment pots for EACH channel.

Here's the amplifier.


The crossover unit at least seems to be of reputable quality. I set the sub/mid LPF at 183Hz, and the HPF for the tweeters is at 2180Hz. Ignore the color bands on the resistors in the pics...they are wrong (as I later found out). It turns out that the "front LPF" part is actually a HPF (that should be set at the same value as the sub LPF), and when coupled with the tweeter HPF (HPF for the tweeter, LPF for the mid) forms a band-pass filter for the mids. The documentation doesn't explain this, probably because it would lead to at least as much confusion. Burn test tones that are solidly in the pass-bands of each filter section & test them. All the planning in the world won't save you if you don't realize you made a mistake. Testing is your friend!


It is very nice that they made the unit in a fashion that allows precise custom settings. I bought a bunch of 0.1% tolerance resistors on DigiKey for this. It is important that the resistors be as close as possible in value to maintain as much noise rejection & phase-coherence as possible.