Rear Speaker Deck Removal and Amp Install

[Heinoceros]

You're not still using the rear channel signal for the sub, are you? I imagine that would amplify (poor choice of words) the problem. I feel like every factory system I've ever worked with has suffered from dramatic bass roll-off in the rear channel, especially at higher volumes.

i am still using the rear channel, and you are right, there is crazy bass roll-off going on. I am changing to the front channel anyway just because of the phone, but it sounds like you would expect the bass roll-off to be less in the front channels? I was not expecting that, i would have expected it to be identical, since the speakers are the same front and rear.

the roll-off is also very volume dependent, which means when i try to add it back in via the high to low signal converter box, it just goes all wacky on me.

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[Heinoceros]

Or u can take the same route as me and just bypass the whole factory radio altogether. I run a samsung tablet that sends the bluetooth signal straight to the bluetooth amp.

that is sort of what i expect to be doing in the meantime. I am just going to use my old samsung s3 phone to drive the usb dac and have a switch between the head unit outputs and the dac output before it goes into the amp. that way if i get a call, i can quickly switch back to the head unit. its not ideal, but until someone makes an aftermarket head unit adapter, this may be my best shot.

 

[neozeric]

Without a bluetooth solution would tapping the rear speakers be best for a sub only amp?

 

[Heinoceros]

So i just hooked up my s3 phone via a usb dac box to the amp, and it was absolutely eye opening. Everything was crisp, the bass, the middle, and everything seemed perfectly balanced without having to do anything to the EQ.

before everything sounded slightly muddled, especially the bass. There was no punch to it, even when the bass was loud. And remember, i am no audiophile. I cant tell the difference between a FLAC audio file and my 256bit mp3 files. But this difference was really noticeable.

So this is very disappointing. While its possible that its just my high to low converter that is no good, i currently doubt it. It is a reasonably high end unit. Its also possible that the rear speakers are just not as good an input as the front speakers would be, i am still going to try that, but i also doubt that is going to help significantly.

I think that the base head unit for this mustang is just a terrible terrible unit. Or its possible that high-low converters are just fundamentally a sub-optimal solution. I would guess they will have an aftermarket kit for it in the next 6 months or so, so until then i am going to hack together some sort of android dac solution.

 

[TheColorRed]

Same...even though the samsung tab got a 10 band eq...I just leave it flat and it sounds awesome

 

[Heinoceros]

Without a bluetooth solution would tapping the rear speakers be best for a sub only amp?

I cannot recommend this at this time. For the reasons i list above, i dont consider the rear speakers to be a useful input for a sub only amp. It appears the very frequencies you are looking for have been significantly reduced in the signal. Someone else might figure out a way to make this work adequately, but i wouldnt bet on it.

 

[neozeric]

I cannot recommend this at this time. For the reasons i list above, i dont consider the rear speakers to be a useful input for a sub only amp. It appears the very frequencies you are looking for have been significantly reduced in the signal. Someone else might figure out a way to make this work adequately, but i wouldnt bet on it.

How about an lc2i ?

 

[Heinoceros]

How about an lc2i ?

that is what i am using now. the accubass is supposed to be able to add back in the bass that is rolled out, but it is just all over the place. it is very hard to restore a signal properly that has been reduced. it will work correct for one song, but sound bad in another. and it just never sounded crisp like the dac source.

 

[neozeric]

On a GT Premium would you do anything differently to hook up the sub amp?

 

[Heinoceros]

On a GT Premium would you do anything differently to hook up the sub amp?

yea, on the premium you have access to line level inputs, its a whole different ballgame. I posted the wiring diagrams earlier in the thread for the premium, but since i dont have one i cant try it. The head unit looks like it produces 4 line level inputs that go to your stock amp. You should be able to pull off of those and get a good unmolested source.

 

[neozeric]

I appreciate all of the help. Would I want to tap in AFTER the factory amp to retain all functionality as suggested in this post?

http://www.mustang6g.com/forums/showpost.php?p=447468&postcount=15

If I do tap in AFTER, would it still be an unmolested source?

 

[Heinoceros]

I appreciate all of the help. Would I want to tap in AFTER the factory amp to retain all functionality as suggested in this post?

http://www.mustang6g.com/forums/showpost.php?p=447468&postcount=15

If I do tap in AFTER, would it still be an unmolested source?

if you tap in after, it will not be an unmolested source, and you will have to do a high to low conversion. i used the autocontrol unit, in his post he is talking about using the MS-8, a 400+ dollar digital processing box to do it.

now i would guess that the premium sound head unit and amp are higher quality than the base unit, so it might be fine. And that MS-8 unit has great reviews, and it has a lot more capabilities than the high low converter i am using. But right now i am skeptical of high-low conversion in general. It may be that the only way to do it is with a high dollar system like the MS-8.

i am not sure why tapping in before for an subwoofer would affect your head unit performance, but again, i do not know this for sure. I think the volume is controlled on the head unit side, not the amp side. All the balance, fade, eq controls in the head unit are added into the input pre-amp. You can just splice in, using it as an input shouldnt reduce the signal for the existing amp (folks split a two signal system into a four signal input with y-splitters all the time, and it doesnt affect the levels as far as i know). And i would guess the phone, bluetooth stuff, etc is also added at the head unit, not the amp, but you would have to try it.

 

[Driversound]

Heinoceros, thank you for pioneering the removal of the rear deck and door panels. I recently upgraded mine to Polk and also dynamatted the rear deck and door panels as well as insulation (http://www.lobucrod.com/). Next project would be pulling the carpet and insulating and dynamat the floorboard. For those looking to change speakers, bottom depth is not much of a problem, it's the top mount that is limited as in the rear deck, there's only a certain amount of top room for the speakers.

 

[ThirtyThreePointThree]

The ms-8 may or may not be an end-all solution, but it's worth its price of $400 imho. I do have a problem with bass response being a little spotty, but right now I think it's because I have a 12" sub in a non-custom enclosure with about 300W rms while I'm running my door woofers with only 20W RMS. There's definitely some peaks and holes right now, but I'm going to re-evaluate after I move to a 10" sundown audio sub and have some power going to the door woofers.

There is also a small bit of white noise with my set-up. It's not too noticeable if I have music turned up. I've noticed the noise gets turned up if I turn the ms-8 volume up, but not when I turn the HU volume up. Got any ideas on that one? :shrug: Your idea of bypassing the factory HU for input reminded me I can drive the ms-8 with an auxiliary input, so I'm gonna try that and see what kind of results I get as opposed to going through the HU via BT/USB.

Would have never thought about bass roll-off in the rear speakers btw. Good catch for the rest of us.

 

[Heinoceros]

The ms-8 may or may not be an end-all solution, but it's worth its price of $400 imho. I do have a problem with bass response being a little spotty, but right now I think it's because I have a 12" sub in a non-custom enclosure with about 300W rms while I'm running my door woofers with only 20W RMS. There's definitely some peaks and holes right now, but I'm going to re-evaluate after I move to a 10" sundown audio sub and have some power going to the door woofers.

There is also a small bit of white noise with my set-up. It's not too noticeable if I have music turned up. I've noticed the noise gets turned up if I turn the ms-8 volume up, but not when I turn the HU volume up. Got any ideas on that one? :shrug: Your idea of bypassing the factory HU for input reminded me I can drive the ms-8 with an auxiliary input, so I'm gonna try that and see what kind of results I get as opposed to going through the HU via BT/USB.

Would have never thought about bass roll-off in the rear speakers btw. Good catch for the rest of us.

so i still dont understand why you would use the high level speaker outputs instead of the low level amp inputs. is there head unit functionality you lose if you use the low level inputs?

driving the ms-8 with an aux should be a good test, although even an aux port is a high level input with different impedance than a line level input. but i have no idea if that matters. the usb to dac converter i got was 20 bucks, but i need to see if i can just drive it via aux port. that is a lot more convenient.

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