I have 08 MCS on order with non-hifi radio. I wanted to change out speakers and add amps to make the audio come alive and still retain OEM look.

I have pair of Boston Acoustic SL65 6 1/2 components laying around from my last car. It may not be the best but it was good to my ears. Now, the rears, I am thinking about Polk MOMO MMC 690 6x9 to get some bass (dont plan to add subs)

I plan to power with JL 300/4 for the components and 6x9. Hope it is enough the push them all.

What do you guys think about mixing brands... I dont have much experience with audio setup... as i just take it to a audio shop and get ripped off all the time..

 

1. "Mixing brands" (a good pair 'here' and a good different pair 'there') is no problem. The non-hifi stereo is happy with "four-ohm speakers".
2. If you select "efficient" speakers (like 92db-95dB efficiency or better), you may not need the amps; an efficient four-ohm driven by the 15W/ch will give you very nice sound anyway.
3. Some good 6x9s in the rear will get you back a LOT of bass.
4. Opinion: It is easy to do your own fronts, a little tougher to do your own rears, and probably a professional job to add an amp (because the wiring is such a bear).

my two cents

 

Unfortunately, the best 6x9 speakers in the world won't get you squat for bass -- the bass response in the non-hifi system's rear speakers is cut severely in the head unit.

See the "Frequency Response" thread for the gruesome details.

I'm going to try a workaround probably this weekend; we'll see how it goes.

 

Nothing like a TEST to calibrate a subjective statement ... !!!

Folks: please see k6rtm's thread https://www.northamericanmotoring.co...d.php?t=150567 for more info ... in short, he has determined that there is a HUGE rolloff in the drive of the rear speakers at low frequencies, and proposes swapping the front and rear channel wiring to put bass back in the rears.
(For the non-engineers: you can put better speakers in the back and get SOME of the bass back lost by the crappy paper-cone originals, but pretty much anything below about 100Hz isn't gonna ever happen with the head-unit and wiring as-is.)

Editorial / follow-on-thought: does this all matter?
For the audiophiles, probably; the frequencies below 100Hz are desireable in much program material out there.
For other people, probably not; frequencies that low (especially in a car stereo) are irrelevant to them, and they can be happy spending just $300 on new speakers that sound better than they did before.
Me, personally: I'm a CHEAP so-and-so, so my preference is "substantial improvement without large cash outlay" ... but I absolutely respect the other camp (and the research that went into that work!)

 

Audio quality:

When I'm in the house, I can imitate an audiophile. I've been there.

I'm not looking for pristine audio in the car. I've said it before in these forums -- I want to be able to hear the sound of happy squealing tires and a burbling motor.

But I'd also like some thumpa-thumpa bass. Not thumpa-thumpa to the point of scaring folks on the sidewalk and setting off car alarms, but enough for some kick in the music -- without booming, distorting, and sounding like *rap.

And unfortunately, while the rear 6x9 speakers could produce some bass, and I'm glad I replaced the OEMs (with Polk db691, which add quite a lot in the midrange through high end in comparison), the audio chain driving them guarantees the thumpa-thumpa just ain't gonna get there.

I also want to do things in a cost-effective manner. Can't afford to just throw money at someone to make the problem go away (besides, what fun is that? Gotta skin up my knuckles somehow).

First steps:

I've got a Boss bass600 10 inch sub with integrated amplifier. It will be a tight fit under the passenger seat (especially since I've got ham radio gear hiding under there), so in the back it's going to go.

My candidate for stealing signals (high level) to feed it is now my favourite victim connector, X9331, in front of the driver's door.

But while I'm in there, why not try something interesting? Why not try swapping the front and rear channels by moving wires around in that connector? That way I get a full fidelity (hah) signal going to the rear 6x9 speakers, and a pretty good signal going to the front combo of 6.5 and 4 inch speakers. Rolling off the front 6.5 inch (Polk db651s) speakers at 100Hz isn't going to be the end of the world, especially if I can pump more bass from the rears. If anything, I should be able to get more volume from the fronts, as I'm not feeding them all that energy in the low end that they can't reproduce.

This swap will also provide the opportunity to test Robin Casady's hypothesis, that someone noticed bass-induced rattling in the rear of the car, and using perfect Teutonic logic, solved the problem by eliminating the bass!

But I'm not worried about figuring out the why. I'm just declaring it broken and figuring out how to fix it, so I can get my thumpa-thumpa bass.

And maybe if I'm good Santa will get me a Clean Sweep and an Alpine PDX 5.

 

I think you nailed it there for me:
I'm not an audiophile in my car ... but I DO play one, back in my house!

The front/rear harness-pin-swap experiment fascinates me -- both as a zero-dollar-cost enhancement and as a repair to something that looks like it was purposely crippled ... and since my replacement rears are good down to 50Hz, I'm definitely looking forward to hearing your results.

 

I did more digging around on the WDS site.

From what I found, both Boost and HiFi systems use the same radio heads (Nav or non-Nav), and run the outputs to the same connector, our favourite X9331.

From X9331, signals either run direct to the speakers, or back to the amp (A18, X10266) and from there to speakers (X256, X257).

This seems to make sense from a manufacturing point of view as well.

So swapping wires on the radio side of the X9331 connector should do the same in both Boost and HiFi systems.

Now I need to get my eyes and fingers on that connector!

 

Sounds so complicated!! I just want to swap out the speakers.. just like all other cars ive owned before... Are all newer generation cars like this?

Reading all the info here... according to k6rtm, you have to find the X9331 and from there --->

1) x9331 ---> signal leveler? like JL CleanSweep) -----> to aftermarket amp ----> aftermarket F/R speakers

2) X9331 --- > Aftermarket speakers with cripled signal to the rear channel.

let me know if im undrestanding this wrong...

 

It's not that complicated. I think it was more complicated for me to verify that things were broken, and measure by how much.

First off, replacing the existing 6.5 and 6x9 speakers makes a tremendous improvement. Do it! Replacing the fronts will take you an hour at most. Replacing the rears will take you maybe two hours.

A lot of people will stop right there. Sounds okay. I'm picky -- that's why I got a Mini rather than a Honda Fit!

The second issue, where'd all the bass go? Replacing the OEM speakers with better ones (I went with Polk; other people have different tastes) improved things, but still no thumpa-thumpa. Why not?

I spent last Saturday morning measuring why not! And collectively, a number of us have been figuring ways to address the problem.

(One way is to throw money at it, but if I was going to do that, I'd have gotten an E55 AMG, right?)

I'm hoping that a simple wire swap at the X9331 connector will improve things a great deal, routing the full-bandwidth signal to the larger rear speakers, and the reduced bandwidth signal (rolling off at 100Hz) to the smaller front speakers.

With the system as it is, just replacing the speakers, it's plenty loud. Hopefully with the swap, it will be loud with more bass.

In your terms, that's aftermarket speakers with crippled signal to the front channel.

Again, this will probably be great for a lot of people. This is a game of diminishing returns! It costs you more to get each additional fractional improvement!

Next step: put the sub package in the boot.

Pull a cable from the x9331 connector to the boot where the sub will go. The sub package I have (boss bass600) has an integrated amplifier with high-level inputs, so it's just connect to the proper speaker leads, and to power.

That's not too bad. The worst part of this whole thing is the effort involved in replacing the rear speakers. Getting to the X9331 connector ahead of the driver's door has to be easier than ripping the dash out, or pulling out the back seats and the trim to get to the rear speakers!

I think this is going to be a good solution. Is it a solution I'm going to be happy with for a long time? Don't know.

I'll live with it for a few months, though, as the next step involves more money, $500 or more. That's going with an amplifier, and possibly something like the clean sweep. Some amps have high-level inputs. One of the ones I've been eyeing, the Alpine PDX 5, doesn't, so I'll need some kind of level converter. Yes, you can get one for around $20 (I have one sitting on the lab bench next to me.

But even the clean sweep is going to be hard pressed to recover from the 12dB/octave filtering on the signal going to the rear channel. Down at 20Hz, you need 30dB gain to get back to the uncut signal level, and then you're going to want 6 to 10 dB of bass boost, yes? That's 36 to 40dB or more of gain at that low end. Think about what all that gain must do to the noise floor... Not pretty...

So if I go with an external amp, I'll be driving all the speakers off the front (unfiltered) channels.

But maybe I won't have to go that far. Only time will tell.

And possibly in the interim, someone will dissect the head unit (or I'll get one to dissect) and see if undoing the high pass filtering is possible.

We'll see. And now that we know what the problem is, maybe someone will come up with a better answer, right? Or if not, at least we're documenting the problem and avenues of attack for the next person who goes down this road.

 

EXCELLENT post, summarizing the new knowledge ... and it crossed my mind that, when you get to X9331 to swap those pins, you might also add a pigtail there while you have everything opened up to avoid having to pull panels again later --

 

ill go digging for this x9331 as ive dont isntalls in a few r56's and pulling the headunit isnt fun... where exactly is it and what colors

 

The X9331 connector has the signals going to the speakers for the normal (Boost) sound system, and the signals going to the amp for the Hi-Fi system.

The X9331 connector is just ahead of the driver's door; it should be pretty much behind the bonnet release:



Here are the pinouts/colours (German, remember?) and functions for X3991 (don't believe me - check it yourself!):

Happy hunting!

 

K6rtm: You are amazing!!! What do you do for living?? or is this what you do for fun?! oh man.. all the stuff you used to figure all the frequencies are all different language for me.. i can only understand the final summerization you make in layman's term.. lol

What i will probably do is this from what I am understanding.

x9331 --- > Front channels --->JL 300.4 rear input ---> rear 6x9 POLK (dont know but one that pumps out more bass)
x9331 ---> Rear Channel ----> Jl 300.4 front input ----> front 6.5 components (BA SL65)

JL 300.4 enough?!?!? it should be i hope..

So where does JL Cleansweep play a role in this kind of setup... i mean it is already going to receive cripple signal and nuetralize it and resend it to the amp... already missing the rear channel 100 mhz signal.. whats the point right?? well.. I think it's still a nice electronic toy. haha Its like having a 1 Farad capacitor in a small scale aftermarket system.. doesnt do crap.. lol


what do you think? 100mhz signal cut off for front components (Boston Acoustic SL65 - not greatest but i already have a pair) would still respond to 90% of signals and i do not thin my ears will really know the difference...

At least doing this, rear 6x9 will fill the thumpa-thumpa that k6rtm is looking for.. heheh thumpa thumpa... sounds so funny but i know exactly what you mean...

 

IMO ditch the cleansweep and just use the front channels to feed your amp, obviouslly u wont be able to use fader control from the headunit but you can dial that from the amp

 

Again, you don't have to be an audiophile to know that amping power to a full range of 6x9s is going to be a downgrade. If you are going to use a 4 channel amp, use the front channels to power the components and the rear channels to power a 6x9 that is at least built to play 80-100 Hz down like the CDT CL-69. I can't seem to scratch my head over and over again why anyone would suggest amping a full range of 6x9s, ESPECIALLY in a Mini Cooper.

There I said it again and am done with my soapbox.

 

Doc--

It's 100 Hz, not 100 MHz (factor of a million in there!)

The JL Slash 300/4 looks like a good pick. My quick calculations tell me that 60-80 watts/channel is right for this kind of installation.

I'd run both front and rear channels of the amp, though, off the front outputs of the Mini head, since the fronts have full bandwidth. I tend to agree with pentavolvo and don't know that something as expensive and sophisticated as a Clean Sweep is needed between the Mini sound system and the amp; it looks like you don't need a level converter with the JL amp.

Once the amp is in place, you'll need to get things dialed in as far as filter settings for the new fronts and rears. That's a by-ear process done to taste.

I'm going to try the channel swap (tonight or tomorrow morning, I hope), take a listen to that, and probably drop in the sub package. That's going to take a while to get dialed in.

As to what I do, I'm a specialized tech writer, building on an earlier career in physics, electrical engineering, and computer science.

But I try to not let that get in the way of having fun!

 

the 300/4 is a great amp and should be more then enough for your application

 

im devistated about the frequency rolloff--

Please keep us posted with any affordable fixes!

 

I'm wondering if the best solution is to add a sub?

 

Im embarrassed by the fact that I was not even in the same spectrum of sound wave as what you were referring to.. LOL

I will take your advice of using front channels of x9331 to go to the 4 channel amp and play with the setting from the amp.

Your brain must be full of numbers and equations from your specialty field.
Im a mechanic... a teeth mechanic... lol i just fix teeth and drill them.

I see what you are saying... ill lose the fader at the radio but spend some time tuning the amp to please my ear....

BTW, i dont think PRO shops know these things would they? Just asking... I can install the speakers but Im kinda scared by wiring the amps and stuff...

 

unless its a shop that specializes in minis they wont know, they will say oh jl cleansweep right away but in reality if u just pull signal from the front channels its relatively clean, plenty cleaner then most cars

using your gains on the amp you can dial in front vs rear

 

Doc--

Don't underestimate your skills. You're far more used to working in cramped conditions and at weird angles than I am! And you don't have to worry about getting hep c (or even a cold) from connectors...

I just posted the results in another thread, and the conclusion is:

Do it!

(now to go put part of the car back together and wire up the sub!)

 

You give me courage my friend!

 

No need for cleansweep or amp with high-level inputs and lots of money.
Just buy the stinger saloc/slocii/sloc (sgn11/sgn12/sgn13) converters:
http://stingerelectronics.com/produc...=13&ParentID=1

SGN13 (SALOC) has level control as well.
SGN12/SGN11 - fixed level.
6$-20$.
http://cgi.ebay.com/Stinger-Adjustab...2em118Q2el1247

It was used in this thread:
https://www.northamericanmotoring.co...=120290&page=2

 

The thread that never dies.

After reading through this thread I saw one mention that the wire feeding the HiFi amp may be good enough to run a splice to a second amp - and another suggestion to run the power all the way to the battery.

I've replaced every stereo and speaker setup in every car I've owned, but always with sale parts and cobbled together. kinda loud and clear through the spectrum is more the goal than winning any sq competition.

I figure, based on the wiring diagram in this thread I'll jack in to the front line feeds (every other head unit that I've paid attention too fed the lows off the fronts as well), before the amp, and run them to an amp i have laying around (2 channel bridged to 300W with built in crossover adjustment and gain) and just bridge to my 10" MTX sub (same setup/equipment i had in my truck).

So the questions are basically - can I feed the always on and switched power of the wires going to the existing amp? Or do I have to rip everything apart in my still new smelling car (i didn't care when it was my daewoo and I'd had it torn apart from dash to rear bumper that night - but this is my *baby*).

Second - should I feed the ground off the amp too with a long ground wire to the right side boot, or risk a ground loop and ground closer to the amp?

After I install this equipment, then I can see about finding some replacing speakers slowly - at least this stuff is just laying around

Thanks!