E30 Audio Overhaul - My Project Details

[bmwman91]

Oh yeah, those SBA drivers are badass. You have to spend SERIOUS coin ($450+/set retail) to get that range of driver quality, generally more. I am not all that excited about the woofer, but it should fit his (the OPs) needs pretty well.

Not that excited about the 10" sub? It has a much smoother response curve than the SP10 & WQ1858, and is considerably more sensitive. Those were definite pluses. Normally I am weary of "low profile' stuff, but this driver seemed to be legit. It IS freaking ugly though, I'll give you that. It's going to be hidden behind a grill & some speaker cloth.

Really, the only item I really feel like I compromised a lot on is the amp. I just cannot justify dropping the necessary coin to get Zapco stuff (which seems to be legit). The car is such a noisy environment that I know it would be wasted money at this point. As much as a no-compromises approach is tempting, putting audio equipment into a car is a compromise to start!

[StereoInstaller1]

Oh yeah, those SBA drivers are badass. You have to spend SERIOUS coin ($450+/set retail) to get that range of driver quality, generally more. I am not all that excited about the woofer, but it should fit his (the OPs) needs pretty well.

[StereoInstaller1]

Thank god, another convert.

When I look at a JL woofer and I see stamped steel frame, 2" voice coil and a foam surround on a tupperware cone, I think "good $100 woofer" and then I see the price is like $250...its like WHY do people buy into the marketing?

There are PLENTY is issues running "home audio" speakers vs. "car" drivers, but most of the issue is warranty, which is virtually nil. As a hobbyist, that is all fine and good, but as a shop the liability is just too high. Too many retards who have NFC on tuning, crossovers, enclosure design...basically, nothing.

I have converted a few shops over to the concept of selling home drivers for car installation, but you need fairly deep knowledge of the product and how to sell a product with no warranty...basically. You can either build in enough profit to cover a replacement or two, or simply tell the customer they get to cover the cost of replacement BEFORE they buy them (good luck getting a salesman to actually cover the fine print on that one) so when they blew them up (as they always do), no one is screaming (as they always do) that "no one told me nothing about no warranty!"(as they always do).

So maybe that would explain why most people have never heard of the "good stuff"...Dynaudio, Morel, Scan Speak, Peerless, Vifa, Audax...or exotic stuff like Aurum Cantus or Bohlender/Graebener, or the new wave of terrific Chinese made product.

To me, developing a good understanding of this process is why I always look for the differences between engineering and marketing. I have no problem paying for engineering, but I really don't like paying a salesmans wages.

[bmwman91]

Do you have a reason you went with SB Acoustics?

Absolutely. "Car audio" speaker brands are, IMHO, 95% dog poop. The ridiculous amount of money you have to spend just to get a driver with a cast aluminum frame (versus stamped steel) is outrageous. On top of that, a great many of the major names in the industry make speakers with decorative cone shapes that look cool. This has zero basis in functionality, and probably causes even more distortion. The best speakers are usually the most boring looking ones. Basically, car-audio branded stuff if a bad value in my book. You cannot get output curves for the majority of them, which is sketchy and makes it hard to design the system. You DO need to be mindful of the environment you are placing speakers in, though. Moisture is an issue in a car, so you do want treated cones. Car-branded stuff seems to at least have this, and that's why so many have poly cones.

I was first introduced to the world of audio in ~2000 (high school) when a friend sold me his sub enclosure with 2x12" Rockford Fosgate Punch drivers. I installed various car-brand stuff (Sony Xplod, Blaupunkt deck, etc). I didn't know why, but it was pretty obvious that one needed at least 500W and big speakers to get good sound. A head unit that can do 200W (50Wx4) was pretty good to drive the 4 coaxial cabin speakers. I sold the stuff a couple years later when I was in college & got into autoX, but I was left with the knowledge that you needed hundreds of watts & big-name equipment to get a good system.

In maybe 2005 or 2006 a friend in college got into speaker building. He made some back-loaded horns with some Fostex drivers and built a 1W tube kit-amp. I could NOT believe what I heard. From 1W, I almost went deaf, AND the drivers he used were only like $50 each (very nice full-range 4" drivers) and had paper cones (which I had previously thought to be bad since, you know, it is "just" paper). The sound quality was above and beyond anything I had heard before. He later built a subwoofer that had to be strapped to the wall to avoid walking all over, and damn near got him evicted from the dorm he was living in. Once again, the total cost was mind-bogglingly low, and it did this with only 50W peak.

So, his projects brought me into reality. I have built some over-the-top speakers for my home theater since then and I am applying what I have learned to the car's audio system. SB Acoustics is very well priced, and they have all of their data sheets available, like any reputable brand should. Basically, their drivers can compete with ones that cost 4X as much in terms of construction quality, consistency & harmonic distortion (it has been measured and documented over at www.zaphaudio.com ). Browse through www.madisound.com to see some fun stuff. It is all overwhelming at first, and you'll probably feel like WTF at the selection of speakers priced from $3 to $6000 (yes, for individual drivers). As long as you aren't putting untreated paper cones into your doors / foot-wells, you are fine using "non-car" brands.

Please excuse my ignorance, can you please post pictures when it comes time to connect the CD43. I am not quite sure how you splice the speaker outputs from the CD43 into Audio Control unit. I'm assuming you have to integrate a male RCA connector onto the end of the - outputs of the CD43?? I know this has been talked about in multiple threads but I am having a hard time visualizing how/where to make these connections.

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.

[TurboFox93]

Please excuse my ignorance, can you please post pictures when it comes time to connect the CD43. I am not quite sure how you splice the speaker outputs from the CD43 into Audio Control unit. I'm assuming you have to integrate a male RCA connector onto the end of the - outputs of the CD43?? I know this has been talked about in multiple threads but I am having a hard time visualizing how/where to make these connections.

[cobraken]

.

[cobraken]

Do you have a reason you went with SB Acoustics?

[bmwman91]

Well, it looks like Christmas came in May. I got home tonight & found that a delivery had been made.

Behold, a box of speakers.


The 6" mid, from the rear...


The 6" mid...from the front...


A pair of Seas tweeters.


The neat low-profile subwoofer.


This thing is nice. The frame castings are top-notch!


Looking more closely at the tweeters...


These are a bit deeper than I had anticipated. I will probably need to cut out the front diffuser to make them fit, but I will only do that as a last resort. It's there for a reason.


I also got a nifty tool. By now I have probably cut 20 holes using an MDF router base & drilling holes in it to pivot from. It is going to be sooo nice to not have to make a new jig every time I want to cut a hole!

[bmwman91]

Today's update:

I got in the trunk & took a bunch of measurements. The amplifier will take some work to mount...it won't fit on the rear bulkhead with the sub. I will probably mount it under the rear parcel shelf (in the trunk). Things should work out nicely back there.

I have also been messing around with ways to mount the CD43 in the HVAC panel. I picked up an extra at a local yard for $4 to hack up. This one is clean enough that I will probably just use it. JB Weld is the best stuff ever. Here is how it fits in. The flash, combined with the light behind it, really accents the gaps. Obviously it will look a lot better inside the nice dark dashboard. I am seeing if I can find a way to get some 1/8" foam in the gaps to prevent the dash backlighting from leaking through, and to prevent rattles.


It took some adjustment, but I got the edges to sit pretty flush.


If you haven't been told this yet, then listen carefully. Don't ever, EVER, set a box on the car's roof while you load stuff. You will forget and drive off with it up there. My punishment for being so stupid will be looking at this every time I am in the car. Luckily, in the car it won't be nearly as noticeable. Cameras & fluorescent light make things look a lot worse than they actually are. Still...STUPID!


How was it done? Yes, JB weld & some 20ga sheet steel. The one over by the OBC was easy. I just snipped the plastic & bent it over to the right position, and then reinforced it with some steel & JB Weld.


The other side was a bit of a pain. We'll see how long this lasts. I can crank pretty hard on it, to the point that the plastic deflects. It seems pretty strong. I want to try this route before I go messing with little fasteners up behind the unit like others have.


I spent the better part of the day doing some other maintenance though. The sunroof guide rails were shot so I replaced them. I also had some exhaust leaks, so I got out the steel hot glue gun (MIG welder) & took care of them.

Later this week I need to design the baffle that the sub will sit in behind the ski pass hole. I will also get into the front fenders & see how much depth a big mallet can buy me.

[StereoInstaller1]

oh yea, MIC is all about the 250 piece minimum order

[StereoInstaller1]

I looked at MIC.com. There were a number of amps on there, but I didn't look too closely since I already bought one. Have you found good stuff on there?

I will probably end up opening the amp at some point, and depending on what I find, I might go through & swap in some higher quality components. I would imagine that they all cheap-out on the capacitors in the PSU, and the output drivers (transistors or FETs). Maybe I will wait until after the warranty expires though!

Hot rod mods on cheap-o amps? Hell yeah! post it if you do, preferably with full analysis.

[bmwman91]

I looked at MIC.com. There were a number of amps on there, but I didn't look too closely since I already bought one. Have you found good stuff on there?

I will probably end up opening the amp at some point, and depending on what I find, I might go through & swap in some higher quality components. I would imagine that they all cheap-out on the capacitors in the PSU, and the output drivers (transistors or FETs). Maybe I will wait until after the warranty expires though!

[StereoInstaller1]

Did you go look at made in china .com?

Some older stuff is better sounding, most isn't. Almost all of it is better built, but for the most part, the cost of performance has come down radically.

[5Toes]

This is great! Can you post a link so I can read up on all this. I know the basics of a stereo but with this Im lost.

[bmwman91]

Haha well I will be using all 4 Ohm drivers, so 60Wx4 & 250Wx1. The sub is 5~6db less sensitive than the woofers/tweeters, so they will require ~4x the power (240W). Really I would have been fine with a 150W sub channel, but hey whatever lol.

Based upon things that were in stock, taxes & some questions about quality, I ended up with the MBQ amp over the PPI one. What has your experience been with MBQ's newer stuff, and current PPI Sedona series amps? I keep hearing that all the new car audio hardware is poop & that eBaying older stuff is "the way." Does the smoke get out of the new ones or something? Back in 2000 or so when I was into car audio (high school, big subs) MBQ was "high end" stuff, but I am not sure now.