DreamWarrior

OK guys...I'm really starting to get the audio bug back...this Bose system is seriously annoying me lately. I've been getting back into some of my older tunes that I used to listen to with my competition rig and the quality isn't even close.

The problem...I *really* don't want to kick out the factory head. I bought the MP3 deck and while its not perfect, it does integrate. I've seen the soundgate loc for Bose systems posted here and am assuming I can use that to get decent line level signals from the unit. What I'm wondering, however, is whether they will be flat. Does anyone know? Does the factory unit apply equalization or is all the eqing done in the Bose amp (which I'm assuming is external somewhere). I'm really hoping the later, because if this factory unit doesn't have a flat output I'm pretty much screwed because Cleansweep's external volume **** is NOT acceptable to me.

So...who knows? If I set the tone controls on the factory head and turn off audiopilot, do I get a nice flat response throughout the volume range?

forbidden

Here is a quote from a friend of mine.
"The cleansweep allows you to auto EQ the car so that the output is a full range non boost signal (cool feature), however you can no longer use the factory volume control or that feature is useless (not cool) you now have to use the supplied external volume **** which is not exactly going to look good in most new cars (not cool), it only has front and rear outputs that require front and rear inputs to work (not so cool) it doesn't allow for summing of channels (not cool), it has no sub out (not cool) but it has a AUX in (cool) The US retail is $499 which will probably be at least $599-$799 CDN retail.

The LC6 is $279 retail CDN (much better), it can take a factory tweeter, mid and sub input and sum them together (cool), it creates a SUB out with a optional sub control **** (cool), you can feed it front signal and have front and sub or you can feed it front and rear and get front, rear and sub (cool) It has a line driver built in (cool), has selectible grounding which is always a issue with OEM systems (cool)"

My advice to you is to use the Audio Control LC6 in a non Bose system and the Audio Control 6XS in the Bose system for reasons like what was pointed out above. IIRC, the eq'ing is done at the amplifier stages in this vehicle.

DreamWarrior

forbidden: would the A.C. 6XS connect to speaker or pre-amp level signals? If it is the former, I don't want it. I want the balanced pre-amp level signals from the head converted to unbalanced RCAs. Upon doing that, my hope is that the pre-amp signals from this head are flat throughout the volume range (so long as the tone and audiopilot **** is turned off).

My concern is that many heads these days boost bass at low volumes (as a "feature" for loudness control) and cut bass/highs at higher volumes (to protect **** factory speakers and accomodate their shitty response). I'm really hoping this head doesn't do that...if it does, I'm gonna have to find someone who can crack the thing open and hopefully bypass it...and that = $$$ .

forbidden

The 6Xs will connect to either type of input signal. The 6XS connection is simple, find the grey preamp lines at the rear center parcel shelf. Cut them about 3" away from where they plug into the Bose amp, extend the lines if you want to, solder on rca ends and you are done. If your going to the expanse of taking apart the factory head unit, you might as well do the full tillt install and do the new head unit at the same time. This would eliminate the need for the 6XS entirely. Find a highly competent shop to do this though. Both RX8's that I have worked on have now used the 6XS as the interface. The RX8 we are working with now does not as we are doing the full headunit install.

DreamWarrior

I don't want to lose the functionality of the red screen...I like it. As far as I know, there would be no ability to connect any aftermarket head unit up to control it. I also don't like the way after market heads look in the car. Personal opinion and all....

As far as the connection, what do the grey wires connect to back at the wiring harness for the head? It could possibly be more convenient to connect there if I go with equalization options up front. Basically, I want to cut in whereever will keep the unbalanced and low voltage runs shortest.

Finally, in response to the flatness question, have you done any RTAing with the car? Are you positive that its flat? This is really my biggest concern. I don't want to buy all this stuff and then found out later with an RTA that I wasted my money. And I can't exactly check before I've bought the stuff because the eqing will be present until I toss the Bose amp if its done there.

THANKS!

forbidden

We still have full use of the red display, save for the clock and cd / radio functions. The climate control etc. still operates normally. What is your e-mail address, I'll send some pics to you (not resized yet so they are a little big).

As far as teh wiring goes, it is by far and away a much simpler install to itegrate into the factory preamp lines in the back of the vehicle. There is little no no extra wire up front, unlike in the rear. The grey wires (5 internally paired) connect to the main molex in the factory radio. Someone in the last week or so posted the pinout diagram for it. Attention paid to the different output levels between the front (powerful) and rear (weak) factory preamp levels on the Bose system. The 6XS has a separate grounding pin internally in it to isolate the input signal and reject noise, so install it in the rear and call it a day.

I have not had a chance to do any RTA work in this car, thus I am far from positive that it is flat but going from what I know about Bose thus far, the eqing is usually done at the amp stages. Either way the Bose amp is a goner in the new system, some degree of experimenting is going to be necessary.

DreamWarrior

Thanks...my email address is dreamwarrior666@yahoo.com if you want to send the pics. I'll talk to my installer about the Audiocontrol product. He mentioned that he's done an install in a Mazda 6 and kept the factory head with good results. I'm not sure how similar the two are. He did mention that the outputs were low voltage and balanced, and hinted that whatever product he'd use would keep a balanced signal.

Anyway...thanks for the help. Hopefully this works out.

For the curious, so far the following is probably going to go in by way of Sounds Impossible in NJ: (excellent shop, BTW, they did my last car and it took home an IASCA trophy at every event it saw)

Zapco Reference amp (likely a 1000.4), however I'm debating. If I go with this amp I see two options:

1) use 2 channels for front and the other two bridged for a sub.

2) I'll bi-amp the fronts and have no sub for now and wait until I have more cash. (This is more likely the option I'll take because it'll leave me a more powerful front stage in the end).

If I take the first option, I'll probably get the DLS Iridium 8.2's and a sub (unsure of which). The problem is I'll be passive on the front stage with limited options for later. I say this because I'd have to buy a sub amp if my subs aren't powerful enough, and then pretty much waste the other half of the 1000.4 amp on wimpy tweets that won't take the power. Not sure if I like this approach. However, the upside is that I can keep the factory speaker locations for everything and I'll have a sub (albeit potentially underpowered) right away.

If I take the second option, I'll get the DLS Iridium 8.3's and power the hell out of the mid-bass (with 2 channels of the amp) and then go passive on the mids/tweets for the other half of the amp. This will give me a very powerful mid-bass/bass response since the 8" woofer in the set can play pretty low (40hz) and with that much power I should easily have the bandwidth in the amp to do it. In this case, I don't think I'll be craving a sub right away, so I'll wait until I can buy a sub setup that fits me. Also, the other side of the 1000.4 is more appropriately used, giving me a more powerful mid/high response also. This seems less wasteful than option 1, while still allowing me to purchase subs later. Its just more costly, and also I'll have to find a spot to stick the mid/tweet combo.

Meh...opinions are welcome...I'm talking more to the installer next weekend.

MrWigggles

It really isn't hard to test how flat the eq curve is.

All you need is a test CD and a multimeter. I will do it tomorrow.

I will try and see how flat the input is to the bose amp AND how unflat the output is.

-Mr. Wigggles

DreamWarrior

Thanks MrWigggles, I'll be anxiously awaiting the results!

Anyone have any comments on the system design so far? I'm still debating which way to go. I wish I had the cash to do it all up-front...but, oh well.

Vaillant

One other thing to consider is there is a non-Bose HU out there as well (it's what I have). If the Bose isn't flat, perhaps the base HU is....

~ Matt

(not an audio guy...but thought I'd share my $0.02)

DreamWarrior

If you buy the MP3 unit, or 6 CD changer unit, do you have to specify which audio system you have, or are they compatible with either. My guess is the latter; why make two different heads?

MrWigggles

Alright,

I did a quick test using Alan Parson's Sound Check and a Fluke TrueRMS multimeter.

I attached my test probes to the front right INPUT of the Bose amp (i.e. the OUTPUT of the head unit) with the attached diagram as a reference.

Test 1:
Volume = 30
Bass = 0
Trebble = 0
Audio Pilot = OFF
Fade = 0

Results:
Nominal differential voltage @ 1KHz = 331mV RMS
Frequency response 20Hz - 20KHz = +/- .3 dB

Test 2:
Volume = 20
Bass = 0
Trebble = 0
Audio Pilot = OFF
Fade = 0

Results:
Nominal differential voltage @ 1KHz = 100mV RMS
Frequency response 20Hz - 20KHz = +/- .3 dB

So that's the good news. The head unit is flat. There is some bad news...

Test 3:
Volume = 20
Bass = +6
Trebble = 0
Audio Pilot = OFF
Fade = 0

Results:
Nominal differential voltage @ 1KHz = 100mV RMS
Frequency response: - .3 dB 20Hz
....................:+10 dB at 120Hz
....................:- .3 dB 20KHz

and

Test 3:
Volume = 20
Bass = -6
Trebble = 0
Audio Pilot = OFF
Fade = 0

Results:
Nominal differential voltage @ 1KHz = 100mV RMS
Frequency response: - .3 dB 20Hz
....................:-11 dB at 120Hz
....................:- .3 dB 20KHz


So you can see that while our head unit is flat under nominal conditions (Hooray), it has a high Q bass control centered at 120Hz (BOOH!!) not a shelfing style. This type of control has VERY limited usefulness since it doesn't do anything to boost or attenuate the subbass only the midbass. I am sure this is just to keep idiot users from overdriving their system, but for those who really want to play around with the low-end, that type of bass control sucks.

Anyway, overall this is still very good news for those looking to yank the Bose system. The headunit is still useful.

In fact, with the right capacitor resistor combo, you should be able to get an "RCA" signal straight off these differential signals without having to use a level shifter at all. I will be doing this in the future (circuit to come in a couple months) but keep in mind you can not ground either end of the differential signal and you should only use one end of the differential signal when doing a direct connect.

Have fun,

-Mr. Wigggles

jaedcem

This statement should be obvious to anybody with a trained ear and moderate experience listening to the stock system. This also seems to be the trouble with discussions about "bass response" on public forums like this - many people have never heard true bass and cannot recognize its presence or absence.

DreamWarrior

thanks Mr. Wiggles, for those of us non golden-ear types (^^^ :p ) your work was very helpful!

Vaillant

I believe they are compatible with either. I'm 99% sure about that.

Another source of info may be a user called "radiodoc" or something like that. I think working on stereos is his job.

~ Matt

MrWigggles

Here is roughly how the system works.

It actually has three components.

1. The headunit (Bose, Non-Bose)
2. Upper source (6 CD, Single CD, MP3)
3. Lower source (MD player, Cassette, and I believe Sirius)

So there are 3 seperate components all 1 DIN Tall. The headunit is simply the radio and that is all.

-Mr. Wigggles

DreamWarrior

Hummm...so when you buy the MP3 unit, you're not changing the actual "head unit" at all? Just the upper source? Is the MP3 unit just an optical drive + processing? Its been a while since I installed the MP3 unit, but I thought I remembered the wiring harness connected to the back of it....where's the "head unit" component located if not in the "upper source" unit itself?

Astral

Is the base (non-Bose) head unit just as flat in its outputs? (With ALC disabled and all other controls set to flat)