High-Fidelity Audio System in 2005 4.8is

[el_duderino]

Hi again. It's Ken, the owner of a hi-fi shop in Portland, Oregon.

An earlier post detailed how the BMW factory audio system works in the 2005 4.8is. ( http://www.xoutpost.com/showthread.php?t=3896 ) I'll refer to this writeup several times below.

After talking with the vehicle owner, he hasn't had time to write up the system, so he gave me permission to write up what we did, and maybe he'll jump in (one hopes : )

The goals were as follows:

- OEM HU retention, with steering wheel volume and 7-band EQ

- Stealth installation

- Improvement of R door speakers to sound like fronts

- More bass - but detailed and accurate sub-bass, not boomy bass.

What we used

First off were the front and rear speakers. We used Dynaudio MD100 28mm silk-dome tweeters and MW160GT mid-bass speakers in the front doors and front dash locations (we did NOT use the OEM tweeter location in the inboard mirror area - just the spot on the top of the dash). If you're not familiar with Dynaudio, they make what are arguably the finest drivers in the world. They are the favorite car speakers of Stereophile magazine, and their credo is to add nothing to the sound at all. Their 7" midbass uses a 3" voice coil and a small magnet that is almost entirely within the voice coil, for ease of mounting. No traditional magnest speaker of this level of performance would have fit. Their 28mm tweeter has an amazingly low resonant frequency and will thusly play great upper midrange without strain.

With these speakers we then used custom passive crossover filters, with Solen capacitors and inductors at 2500 Hz. The OEM passive xover point is 3000 Hz - we lowered it to 2500 because the tweeter, with a well-damped resonance at 1300 Hz, is capable of handling the upper midrange quite well - and because with a dash-mounted location, we could elevate the vocals into the windshield without a lot of "float" (like you get with a xover point around 4K or 5K).

With the rear doors we used the Dynaudio System 240 GT - same drivers, but with the Dynaudio 3K passive crossovers. Since we put the tweeters into the same locations in the rear doors as the OEM mids had been, they were very close to the midbass drivers, and did not benefit from a lower crossover point.

With the F doors we let the Dynes play down to about 65 or 70 Hz, and down to about 90 in the R doors. More on this later.

Because of the cramped quarters in the rear, we used Genesis Profile Series amplifiers at 34mm - 1-5/16 - tall. They all have internal fans so we felt they could take the cramped quarters without getting too hot (we may end up ventilating them a bit more). We used two 75w x 2 amps and one 350 watt mono sub amp. As the pics show, we used the tray on top of the spare tire as an amp tray, and the spare is fully accessible and the tray is easily completely removeable if need be, for service.

For subwooferage, we used a single DLS Magnesium MW110 in a sealed enclosure. (I know that DLS recommends a vented enclosure for this driver. I've spoken with some very high-end DLS dealers around the country, and EVERY one I spoke to uses this driver sealed. I have one sealed in the trunk of the shop demo car and it sounds great. I've modeled this on the computer and it models fine sealed. I don't know why DLS made this recommendation.) We ran the subwoofer at about 70 and down. We also (as the pics show) installed a grille (the OEM subs were firing through 2mm of plastic). We used a Dynaudio 8" grille because the material was the right color and texture for the BMW. This is the only visible modification to the vehicle without opening something up.

The subwoofer also has a 3" voice coil, and uses a magnesium cone. This is a very light cone material, but is relatively soft, so acoustically it's more neutral than aluminum, a trendy woofer cone material right now. We've used this woofer a lot, and it tends to sound detailed and accurate rather than boomy.

The sub amp has an output level control knob. We installed it into the ashtray (owner doesn't smoke and doesn't allow it in his car), along with a fader knob. We had to install a fader knob in order to get full-bandwidth sound for the rear speakers. Since the OEM system had rear-door frequency-response issues (see the initial article), we routed full sound to the R doors by splitting off of the F doors and then running an Alpine 4312 dual-amp balancer (the only thing Alpine still makes from when I entered car audio 18 years ago: )

As the other thread mentions, we used a Phoenix Gold 4-band parametric EQ (now discontinued) to correct the summed frequency response and act as a line driver from the stepdowns into the amps. A p[arametric EQ allows you to boost or cut certain frequencies (like a graphic EQ), but it also allows you to decide what frequencies are affected, by adjusting the center frequency and the bandwidth to each side of the center (how many notes are also affected around the cetner freq).

Using the line driver helped a lot - the sound came alive a bit when we drove those amps harder. We also were able to set the EQ while measuring the signal with a real-time analyzer on the preamp level. We also had another parametric band in the sub amp, which helped out a lot. The HU's 7-band graphic EQ was left flat for our adjustments, and thus the owner could adjust it for different songs as needed.

How does it sound?

(Warning - audiophile wine-tasting words to follow!) The vocals are clear and solid out over the hood in front of you (as stereo was meant to be). The midbass is very solid in the front too. You cannot tell the location of the subwoofer with most music - it sounds as if all the bass is out in front of you (as it should). The rear fill - something I usually detest as a commie plot - doesn't hurt much because of how low the tweeters are, how we set the tweeter output to Low on the passive xovers, and how we raised their highpass xover point relative to the front speakers, keeping the drum kit in front of the listener rather than in the back seat. It doesn't blow you out of the car with volume, but it can handle dynamic musical peaks without strain, as well as very low bass notes. There is a hint sometimes that the sound could be deeper overall - a sense of "flatness" or maybe alack of warmth - but I ascribe this to the use of the OEM Hu, and it's really a very slight issue, not an objection (especially relative to the OEM system, which I thought sounded very two-dimensional with no illusion of depth at all).

The high notes are detailed without sounding etched or bright, and have a little bit of "air" around them. There is no sensation of vocals hovering or floating, or the drum kit jumping back to the sub and then forward to the midbass. It's a very stable and well-localized system. The bass sounds fast and detailed - with some recordings, the bass seems to have texture to it - and the bass level control lets the driver change the woofer output level for highway driving or slower, surface-street driving (as well as the music being played, of course). It doesn't go down and grab the very lowest notes, but it will growl as needed.

My biggest complaint with the system is the BMW head unit's refusal to display any volume setting indication. Unless I just missed it, you can't tell how loud it will get until it gets that loud. Irritating.

I wouldn't recommend these for 56k-readers:

http://kward1.homestead.com/X5pics.html

http://kward1.homestead.com/X5pics2.html

http://kward1.homestead.com/X5sysdiag.html

About the gear we used:

www.dynaudio.com

www.dls.se

www.genesis-ice.com

Anyway, that's what we did, turned out great, although a bit more work than any of us thought! Any questions, pm me, or ping me at kenw at avincar.com, thanks!

[JV]

Good looking work and more detail than I'd ever need to hear about car audio.

Now, the only bit of info you didn't include here is how much did all that run? Parts, labor, design, all together how much?

JV

[el_duderino]

Well, it wasn't MY purchase, if you know what I mean. I guess if someone came in and wanted the exact same system in the exact same X5, we would charge just under $5K.

For a lower-cost system with the same architecture but with lower-cost speakers, one could pretty readily save $1-2K.

Not a cheap purchase. Of course, you guys could've bought Kia Sedonas, I guess. : )

[JV]

Originally Posted by el_duderino

Not a cheap purchase. Of course, you guys could've bought Kia Sedonas, I guess. : )

Or a new gen ML class, which looks just like the Kia. Thanks for the info. With all that work and customizing, 5K seems a bargain.

JV

[UCrewX5]

Excellent write-up, thanks for taking the time to share the knowledge and details

[boostmiser]

Very nice writeup. I'm interested in the loc's. Are they powered or stand alone? I recently bought an AudioControl LC6. I'm curious how you would set up the LC6? I want a similar setup with the stock hu (I have dsp). Any info you could share would be appreciated.

[el_duderino]

Thanks for the kind words : )

I tried the LC6 in this car as a test and was disappointed. Was noisy, although I wired it in and listened and removed it without much experimentation. Was checking to see if it was a magic bullet, and it wasn't.

The other problem with the X5 and the LC6 is number of channels. See my other post for details, but you're working with 7 pairs of channels if you leave out the 4 channels for the rear doors. You would need TWO LC6s (which is what I understand some of the Mercedes guys are doing).

We used modified Soundgate /Navone units. (We modded them). Same units used in janix' X5. Summed their outputs and ran them into the EQ. Having done this without the EQ (added the EQ towards the end of the installation), I don't see how any shop could flatten out this particular response curve without one. You can play games with reversing polarity on the mids, and relative potentiometer levels on the LOCs all you want, for this I think you need a darn flexible EQ, and I've always been somewhat anti-EQ.

I have read in many posts that if you unplug the digital coax from the changer the whole system is then analog from the HU into the amp (INCLUDING the CD changer). If that's true, yours might vary with volume at that point. Or maybe not. If yours varies with volume, you are way ahead of where I was on this car.

[Mylo_T_Cat]

I wish you were closer to Madison WI, cuz I'd love to have you upgrade the stereo in my 2005 4.8. For all my vehicles, other than the 2 X5s I've owned, I've had the great folks at "AMS" (here in the Madison area) install upgraded audio systems. However, having taken both X5s out to them for evaluation, they seem reluctant/unenthusiastic about upgrading an X5. I would love to hear the Dynaudios in a vehicle installation.
Dave

[Jeff330xi]

Nice write up. I love Dynaudio speakers. I used them for rear speakers (mid bass only, for fill) when I was competing in IASCA. I really loved my A/D/S speakers too.... wish I would've saved those when I sold the car... oh well.

What's the Vb for the sub enclosure? I wish someone made stealth boxes like those commerically available. I just don't want to go through the hassle of glassing a box myself...

-Jeff

[X5 Sport]

Nice install!!!

I wanted to ask a couple of questions which I hope you may be able to answer!

I Can get Dynaudio speakers at a good price however I dont want to put amps and all the other stuff in my car, as BMW in the UK would invalidate my warranty.So if I just put the same speakers that you used will they fit easily,So old speakers could go back,and would I need to use any cross overs or would the standard BMW work and would I gain a much better sound ? I have DSP if that helps

Many thanks