[Swagger]

I started an extensive audio renovation this week. I'm going to replace the speakers in all four doors and the rear deck and also add a JL Audio sub enclosure. Here are a few pictures from the first day. Most of the wiring is in and the trunk is fully dynamatted. I'll post more pictures and updates as the project progresses.

[Swagger]

Here's a picture of the AudioControl LC8. This acts as an OEM integration module that takes the signal from the stock amp and creates a usable clean preamplifier signal.

More pics and updates to follow.

[canucklion]

nice, thanks for sharing dude!

Please post pictures of the door removal/dynamat process, I plan on doing it in the near future, and I'd love to see pics of the process!

[avincar]

So, a couple of questions.

Which OEM system do you have?

The LC8 is a summing-capable line output converter. It does not have any EQ or de-EQ capabilities. How are you reversing the EQ emphasis in the BMW amplifier? Are you?

Are you summing the channels together? Or are you retaining the OEM F/R/non-fading bass? If you are summing, how are you tuning the levels?

[Swagger]

The OEM is the Logic 7.

I'm not trying to reverse the eq. The primary function of the LC8 is to sum the channels of the pre crossed over factory outputs. This is necessitated by the fact that OEM speakers and their amplified systems are crossed over on the OEM amp because the OEM speakers are not very dynamic in their acoustical reproduction capabilities.

In an ideal system the goal is to maintain the eq at a flat or neutral setting therefore not introducing any coloration into the reproduction of the audio signal.

The summing of the channels together refers to the individual speaker, not the f/r/sub application of the preamp output... that functionality is intact.

[Swagger]

I'm not planning on using Dynamat in the doors but here's a few pics or the disassembled doors. I hope this helps a little!

The pictured speakers are still the OEM. The Focal's haven't arrived yet.

[smellthebeans]

Originally Posted by Swagger

The OEM is the Logic 7.

I'm not trying to reverse the eq. The primary function of the LC8 is to sum the channels of the pre crossed over factory outputs. This is necessitated by the fact that OEM speakers and their amplified systems are crossed over on the OEM amp because the OEM speakers are not very dynamic in their acoustical reproduction capabilities.

In an ideal system the goal is to maintain the eq at a flat or neutral setting therefore not introducing any coloration into the reproduction of the audio signal.

The summing of the channels together refers to the individual speaker, not the f/r/sub application of the preamp output... that functionality is intact.

Damn! whished I had paid more attention in Rocket Propelsion 462

[canucklion]

thanks for the pics, Swagger

hmm, it looks like there's no space to dynamat the doors!??!?!

would you mind outlining the steps you took to take apart the door panels? there are people that have done it before on this forum, but no official DIY posted. It looks like you did a very nice job, and I would like to find out what your technique was.

Thanks!

Originally Posted by Swagger

I'm not planning on using Dynamat in the doors but here's a few pics or the disassembled doors. I hope this helps a little!

The pictured speakers are still the OEM. The Focal's haven't arrived yet.

[avincar]

Easy, tiger.

The fact that the OEM amp has crossovers in it is not due to the shortcomings of the speakers. They have shortcomings, but crossovers in the amp are not a function of that.



The reason I'm asking these questions is that I've seen many oem integration installations which don't start off with an analysis of the system.

You don't need to re-sum the channels IF the crossover punt is appropriate to the system you want to install.

If you don't know the crossover point, you don't know if that's true or not.

The only way to determine that is to use a real time analyzer.

All your talk about "coloration" sounds great - but when you test the output of the amplifier to determine the crossover points, you will find a significant EQ curve which is applied to the amp signal, including a 9db+ broad-Q peak centered at 1k.

In short, I suggest that the crossovers in the amp are very usable, but the internal EQ of the amp will mess things up unless you reverse it somehow.

Originally Posted by Swagger

The OEM is the Logic 7.

I'm not trying to reverse the eq. The primary function of the LC8 is to sum the channels of the pre crossed over factory outputs. This is necessitated by the fact that OEM speakers and their amplified systems are crossed over on the OEM amp because the OEM speakers are not very dynamic in their acoustical reproduction capabilities.

In an ideal system the goal is to maintain the eq at a flat or neutral setting therefore not introducing any coloration into the reproduction of the audio signal.

The summing of the channels together refers to the individual speaker, not the f/r/sub application of the preamp output... that functionality is intact.

[avincar]

Here is a pic of the screen of a NT Instruments 1/3-octave RTA, on the Front speaker-level outputs of a non-Logic 7 amplifier in an E90, with the M-ASK CD player playing a 20-20k stereo pink noise CD test track. The tone controls were flat. While the Logic 7 amp probably has different EQing, it still has EQing.





Here is the amplifier's output to the underseat subwoofer:



These measurements were taken with the speakers still in the circuit (otherwise the measurements are incorrect).

Now, the sub crossover filtering -3dB point seems to be at around 80-90 hz. perfectly acceptable.

The high-pass -3dB point seems to be around 150 hz, depending on where you decide your reference level is, since there is a lot of EQ curve to the signal, that is not totally apparent. Crossing a 4" mid at 150 is not an inappropriate thing and is not indicative of a sucky speaker.

But you will have a dip between 80 Hz and 150 hz if you sum these two channels together with an LC8. You may or may not get the relative levels matched, since the wattage output is different, unless you set the levels with a real-time analyzer - BUT the LC8 gives you no facility to address this disparity in crossover points.

BUT... if you used some multichannel EQ means to de-process the OEM EQ, you could also massage the crossover point response a little and correct this dip.

When you talk about coloration, it's important to remember that 10K+ audio systems with vinyl playback use RIAA EQ in the records they play, and de-EQ in the phono preamp they use. No bad thing here, if it's done well. No reason that EQ can't sound good, just because is often has sounded bad when done poorly.

I would suggest that you spend about $350 on a Phonic RTA and some cables and you can see what I mean.

When I talk about OEM HU integration, I look at the signal type, the response, and the range. The speaker level output of the amp is easy to work with, the range I think is usable - but the response is what will mess you all up if you don't plan ahead.

Good luck and keep us posted!

[///Matt]

SOMEONE here is an Audiophile. I'm not gonna say who, but I think we know. =)

[avincar]

Originally Posted by ///Matt

SOMEONE here is an Audiophile. I'm not gonna say who, but I think we know. =)

I think you mean Swagger.

I'm just a pragmatic guy with a bunch of tools

[Swagger]

Nah, Avincar knows what he's talking about!

What would you recommend to clean the signal out of the stock amp before sending it along to the two aftermarket amps? Would you recommend getting rid of the LC8 altogether or adding something to the mix?

My initial reaction is that the sound is a little cloudy. At a low volume, it almost sounds like pillows are over the speakers. The bass sounds incredible but I'm more interested in clean sound. Like you said, hearing every instrument with a sound stage pushed a little forward.

I feel like I've lost what little stage the Logic 7 had.

I'm going back on Monday to the shop to have the guys take a look after they speak to Audiocontrol tech support. The car sounds, like the door chime, PDC beeps, and navigation speech are annoyingly loud. These sounds are disproportionate to the stereo volume by a huge margin.

What's your take on this? Any suggestions?

Thanks!

PS - The install LOOKS incredible. I'll post some pics when I get a chance. I'd trade the looks right about now for some beautiful sound!

[Swagger]

Canucklion,

I had this work done at a local high end car audio shop. I'm too chicken to take the car apart to that extent! I'll try and find out how they remove the panels. Avincar can probably help you; he's taken apart quite a few of them!

[bigjae1976]

Looks like a promising start. I'm interested to see how it turns out by using the auto-sum feature with the Logic 7.

I saw a system in a 7 series integrating the OEM head unit. Apparently, it was pretty tough to get it to sound good. Not sure how much eq power they had.

[avincar]

Originally Posted by Swagger

What would you recommend to clean the signal out of the stock amp before sending it along to the two aftermarket amps? Would you recommend getting rid of the LC8 altogether or adding something to the mix?

My initial reaction is that the sound is a little cloudy. At a low volume, it almost sounds like pillows are over the speakers. The bass sounds incredible but I'm more interested in clean sound. Like you said, hearing every instrument with a sound stage pushed a little forward.

The right interface tool in this case depends on the installer.

The Rockford 360.1 and .2 seem to sound pretty good (better than you might expect given the Rockford rep for cranking over fidelity). They adjust themselves when installed correctly. They MAY also obviate the LC8 (depending on your system architecture). The .2 also has a 1/3 octave EQ and time delay per channel, the .1 a 5-band graphic.

The JL Audio Clean Sweep is a bit more problematic in some applications (I think this one is fine), but can take the output of the LC8 in most cases, and also adjusts itself.

The AudioControl DQL-8 - a product we can be fairly sure they have access to if they are an Audio Control dealer - does NOT adjust itself. It really requires that the installer use their real-time audio analyzer - with AC dealers, that's usually the 3050/3055 - and connect it to the output of the DQL-8, and play a pink-noise CD through the OEM system (the way that I did) and adjust the DQL-8 controls until the signal coming out of the DQL-8 is FLAT.

I would also consider a Zapco DSP-6 - but it requires a very skilled installer. 10 band parametric EQs per channel, time correction, and presets. It's a sweet deal.

Most installers have never done this before. Many don't know that their RTA can measure electrical signals.

That is not to say that a flat response sounds best ACOUSTICALLY. But you want a flat ELECTRICAL signal going to the aftermarket amps (except for whatever crossover filtering you do) BEFORE you start EQing for sound. Then the speaker location and electromechnical tendencies will create your ACOUSTIC response - which may (or may NOT) need EQing.

The kink is that they should have used the RTA to test this already. If they haven't, they may not be an AC dealer (they are required to have SOME RTA, and the 3055 is usually what they have). So if they don't have an RTA or are not comfortable with using it, the self-adjusting interface devices may be the best bet. the Alpine H650 is coming out someday, and it will self adjust both the electrical signal and the acoustic response, but no one has heard one yet so let's not hold our breath.

If they are an AC dealer, you should be able to get them to take the 3055 out to your car, plug an RCA cable from the output RCA of the LC8 into the RCA input of the 3055, play the pink noise test track, and see what's coming out of the LC8. THEN you can decide what to do to correct it.

I've done the E60 5-series and it wasn't that hard to make sound good - but that's me, and I use these tools every day.

If you are interested, I would be happy to explain what I'm talking about to your installer. I was the tech support manager for a large 12V manufacturer for years, and I am fairly good at explaining these things to installers without stepping on their toes. Your call, happy to help if you like.

I should mention that I have hated EQs for years. You want to have as big and amp, and as good-sounding an amp, and the best speaker system there is, before EQing, in my considered opinion. But with OEM HUs giving us pre-EQd signals, we need good-sounding EQs just to get us back to square one.

[Swagger]

Avincar,

Thanks for the great reply. I had to read it twice but I think I learned something!

Here is the equipment that I'm using:

AudioControl LC8
Memphis MCA-3004 (Amp for 6 new Focal speakers)
JL Audio 500/1
JL Audio Dual 10 W3 v3-2
Focal Polyglass 100 V Slim 4" (Front Doors / Rear Doors / Rear Deck)
AudioControl Subwoofer Level Control

The rear doors and rear deck are bridged from the rear channel of the Memphis.

I'm suspicious that some of the wiring from the stock amp to the LC8 may be incorrect. First off, the balance is backwards but that may be as simple as inverted RCA's going the the Memphis.

It almost sounds like the rear channel is in the front and the front channel is in the rear. It fades normally but I hear highs bouncing off my rear window and midrange coming out of my front speakers.

I'll have them check all of the wiring.

Have you ever heard of the native car sounds (Door Chime / PDC beeps / Navigation voice) being obnoxiously loud after a setup like mine. The PDC beeps are almost deafening and the Nav voice sounds like it's going to blow the speakers. What do you think could have caused this?

I'll let you know how it goes tomorrow. If we don't make much progress, I may take you up on that phone call. You're incredibly generous to offer and I really appreciate it.

If all else fails, I'll make a road trip out to Oregon!

Thanks again!

[avincar]

Well, if they got L and R swapped, then it's POSSIBLE that they got polarity wrong somewhere too. That would sound weird.

But the basic problem is still that the signal going into your amps, which "should" be a flat signal, is geting a peaky signal which looks something like those screen shots instead. It's not identical, because those of of a non-Logic 7 system.

Your comment on R speakers is why I tell all my clients that rear speakers are a Commie plot against our North American way of life...

[Swagger]

Just got back from the audio shop. They switched the front crossovers from -3db to 0db. They gave more power to the fronts and eased off on the rears. They also switched the RCA's to reverse the balance mix-up.

The car sounds a thousand times better. I still would like a little more taken off of the rears and maybe have the crossover lowered in the rear deck. I still hear a hint of cymbals smashing off the back window.

No immediate solution for the loud car sounds such as door chime / pdc beeps / and nav voice. The shop's BMW contact said that the latest progman update (or one since March 06) addresses this issue with electronic control over the volume. Can anyone confirm this? I'm bringing the car in to BMW in a few weeks so I should know then.

Engine noise is still a minor problem. They connected a group loop but it made the whine worse. Both amps are grounded with 4 gauge wire. Any suggestions on how to eliminate the engine noise completely?

All in all, a big step. I'll be interested to see if the Alpine H650 (when it comes out) that Avincar spoke of, or something of its like, will help get me over the final hurdle. The car sounds great but I can still hear a few weak spots that I don't think playing with the gains, levels, and crossovers will solve.

I'll post final pictures when the shop emails them over. The owner is out of town and will send them over when he returns.

[avincar]

Dude, I'm not feeling too cool with this shop. Are you in the city? You might want to contact Ron at Installations Unlimited in Union, NJ. VERY smart guy, knows BMWs very well, BMW owner.

BTW, if your shop is owned or run by a guy named V Sokolov, run, don't walk, RUN, away from there. Hackamundo.

Have they used the RTA on the output? Do you yet KNOW what the output's doing?


My treatise on RPM-related noise.

All systems have noise. In some, it's audible. You want the noise floor to be inaudible.

If the gains are too high - if the amp input sensitivity is too high, if the LC8 output level is too high, etc., then you can hear the noise floor. Resetting the gain structure might solve the problem.

Ground loops make the noise louder. 95% of RPM-related noise is due to a ground loop (electroncs traveling to ground through the (-) signal connection, usually in an RCA cable). Ground loop isolators stop the ground loop they are connected to. If you have a 4-channel amp and you have a ground loop on both sets of channels, and you try a GLI on one side and not the other, your noise may not change. You need to try one on each, or one on one side and the other side unplugged.

If the GLI is next to a power wire or a OEM component which emits EMI, you will have more noise with it in the circuit. GLIs have transformer coils in them, and they are antennae for electrmagnetic interference. EMI in the audible range has a VERY short range, so moving it slightly can solve this. This is inducted noise.

Inducted noise is rarely the problem. This is when something - an RCA cable or a passive tweeter crossover - is picking up EMI out of the air. In rare cases a component such as the LC8 or an amp can pick up EMI. If your tweeter crossover is the issue, the noise will be audible from the tweeter EVEN with the amp fuses pulled and the amps disabled (or in your case with the LC8 unplugged - that should disable your amps too). Easy test, worth doing first, just to know.

I am not saying that the LC8 is never the problem - I think they are kinda noisy, but the gains usually take care of it.

Also, the E90 makes horrendous mechanical whine in the trunk which is RPM related. It's the fuel pump. Make sure you are testing with the trunk lid closed and the seat closed.

[Swagger]

I don't think the shop has an RTA. I've asked several times but haven't gotten a straight answer.

Say I do find someone with an RTA (I work 20 minutes from Union, NJ) and he hooks up to the output and finds something really funky (which he most definitely will!), does he have the ability to flatten it out with my current setup? Wouldn't I need something else with the ability to de-eq the stock amp?

If I were in the hands of an expert, like you recommended, would you recommend swapping the LC8 out for DQL-8? I checked out the Zapco DSP6 but it's a little out of my range.

I suspect it's always better to use an RTA and manually adjust than to just add a device like the JL Audio Cleansweep and let it do its thing.

As always, thanks for the advice and the education.

[Joe Bimmer]

Originally Posted by Swagger

I don't think the shop has an RTA. I've asked several times but haven't gotten a straight answer.

Say I do find someone with an RTA (I work 20 minutes from Union, NJ) and he hooks up to the output and finds something really funky (which he most definitely will!), does he have the ability to flatten it out with my current setup? Wouldn't I need something else with the ability to de-eq the stock amp?

If I were in the hands of an expert, like you recommended, would you recommend swapping the LC8 out for DQL-8? I checked out the Zapco DSP6 but it's a little out of my range.

I suspect it's always better to use an RTA and manually adjust than to just add a device like the JL Audio Cleansweep and let it do its thing.

As always, thanks for the advice and the education.

First of all, that audio shop is a joke. No respectable audio shop would give back the customer's car with alternator whine coming through the tweeters.

You should definitely have them hook up a voltmeter and match the correct input voltage senstivity settings from the OEM amp line out RCA's to the pre-amp input gains, and from the pre-amp outs to the amp ins. Are they grounding the LC8 into the amp, and then having that ground go into metal? Ensure they're using one common ground for all components. If it's still there, then they should try increasing the distance between the RCA's and all powered wires in that wrap of wires in the above pics. Also make sure they are using the best possible shielded RCA's.

Avincar has been spot-on with his recommendations.

Good luck man!