Denny79

Hi folks,

I have 2011 Convertible with Bose sound system and Navi. I have been doing some research and talking to some installers and audio professionals about upgrading the audio system. What do you think about the following:

HU - keep Navi for now (replace later on 2nd stage of upgrade)
Front speakers, one of the following:
- Seas Lotus reference (2-way component with 6.5in midbass)
- Dynaudio 362 (3-way component with 8.0 midbass)
- Dynaudio 342 (3-way component with 6.5 midbass)
- Focal 165KR (2-way component)

Rear speakers - probably skip them or get something relatively cheap for the fill

Sub and box: one of these:
- Two Vette Nutts boxes for passenger and driver sides with JL10W3V3 subs
- JL audio with behind the seat subs and recommended 8" subs for that enclosure

Amp for the sub and components (are these good?)
- ARC 600x1
- ARC audio, 500W, 4 channel or
- Exile Audio S400.4 800 Watts 4 Channel


Sound Processor:
- JBL MS-8 MS (to level out the output from the HU)

Location of tweeters:
- in the A-pillars

What do you guys think about this setup? Any recommendations? I am trying to get pretty good sound quality without going too expensive.

WAwatchnut

Your idea of "without going too expensive" is definitely very different than mine!

At the risk of going on the higher end of your budget, I would recommend the Dynaudio 362's, combined with the Arc amps, and the VetteNuts boxes. The 8's in the doors will allow you to keep bass output out of the front, ensuring proper staging. The Dyns are very detailed and smooth, which Is a major plus in the Vette.

Thrash

You didn't say what tweets you were using for the pillars, or specifically for that vs. the 3.5" door speakers (6.5 & tweet components in doors?), unless that was taken care of by the 3-way units. I'm using Focal components in the front and rear, Pioneer subs in rear cubbies.

I'd go 6.5 & tweet -or 3.5, in doors and another tweet set for the pillars. Rear fill is up to you, plenty do and don't use those.

Nonetheless it sounds like a good plan, attached is my plan I drew, hoping to install this week, just waiting on 12 gauge twisted speaker wire that I ordered ...

Turbo6TA

For about $1,250 total including the wiring and the rest of the misc stuff, you can get something in line with what I installed below ... great sound without spending a bunch of money. Big improvement over the stock system!

This system also retains the OEM radio


5-Channel Amp
Arc Audio
XDi805

2-Way Component Speakers - Doors
Focal
PS 165

2-Way Coaxial Speakers - Rear
Arc Audio
XXD 5029

Subwoofer Speaker
JL Audio
10W3v3

Subwoofer Corner Sub Box (Coupe) VetteNuts

Sound Deadener Matting
FatMat

Denny79

Thanks Thrash! For the tweeters, I planned to use the tweeter, which comes with the component set.

Denny79

What I mean without getting too expensive is without crossing the exponential rise in the price for the top-notch sound quality, which normal ear cannot distinguish.

Thank you for the recommendation. Do you know if Dynaudio has a lot of build-up (being 8'' rather than 6.5'')?

Denny79

Have you experienced any issues with the stock head unit? Is it Navi? I was reading that for Navi usage of the sound processor is highly recommended (to offset the factory eq. curve).

WAwatchnut

Do you mean requires a lot of build up? I don't believe so, but I'm not sure of the depth of the Dyns. They should be simlar to the Morel 8", or the MBquarts that I'm using, which required a 1" spacer on the door. You also want to completely deaden the door. If you limit the 8" to 80 hz and above, that should work pretty well.

Ideally, some type of enclosure should be fiberglassed for the 8" - since there's a 10" hole, and about 2" of depth, you'd have to build out from the door, but you'd probably be able to build a .3 ft enclosure for it. But it's not completely necessary.

Yeah, I know a lot of people who would go the extra 2-5x on the cost of the amps, but there you really get into diminishing returns. With the car turned off, maybe you'd hear a difference, but under any other conditions, it's pretty much money wasted. But I think the Dyns are pretty hard to beat, and well worth the money.

Thrash

You might consider tweets in the upper door AND in the pillars, many have taken this approach, but I want a touch more mid up high so putting 3.5 mids in the upper door, tweets on the pillars ...

Denny79

If I go with the 3-way component set, that's what I will do. Tweets in the a-pillar, 3.5 in the upper door.

Fasthotrod

If you check the C6 FAQ's you'll find that the factory headunit has a flat/decent output already... there is no need to purchase something like a JBL MS-8 to 'level' out anything in that regard.

Now, if you are adding the MS-8 because you want to easily setup the system and have a lot of control over the crossover points, frequency response, etc... then it's a great choice.

Just don't think that you need one when it's simply not the case.

Thrash

Cleaning the stock levels is a good idea, I'm installing the AudioControl Matrix 12v Line Driver, ensures signals are balanced, clean and optimal (look up the specs on this unit, impressive quality). I have a spare Alphasonic 8v Line Driver that is FREE for the asking if you cover the shipping ...

Fasthotrod

Are you talking about the Audio Control Matrix Six Channel Car Audio Line Driver or something else?

When you say 'cleaning' the stock levels, what do you mean? Cleaning up noise? If so, what kind of noise?

You say that it's balanced... what and how, exactly?

NYC6

Two of the things I learned arounf here.
1-everybodies version of expensive is different.
2-everybodies normal ear is different.
You have some that pull out the whole OEM system and add thousands of watts of power and squeeze 2 13" subs into the back to be happy and others, only removing the center speaker is enough to have them say "the sound quality is so much better now, I dont need to do anything else".

Heres what I did to please my normal ears.
JL Audio(C5-650 Components, XR-525 Coax, JL Stealthbox 10W3, Amps 450/4v2 and 300/2v2, Kenwood 8019 H.U.

initially I left the stock HU but wanted good ipod interface and BT, the Kenwood gives me both.
Komoman(one of the guys worth listening to around here) says, the stock HU signal isnt that good and SQ can be improved by replacing.

Thrash

That would be the unit -the AC Matrix, problem with stock HU's is maybe 2-4 volts max of signal clarity, easily overpowered and stepped on by even a connected iPod, thus noise and buzz is created. Matrix kicks it up to 13 volts so that rides above the other interferences, plus other benefits ...

Two, Four or six Channels of input power to six Channels of Output:
- Stock 2 or 4 channel outputs gain extra sets of output (6 channels) for extra speaker sets -or subwoofers
- 24 dB of Signal Gain - 13 Volts Peak Output
- 12 dB of Signal Attenuation
- PFM Subsonic Filter
- Output Level Controls
- Balanced Differential Inputs
- Linkable Inputs - 2, 4 or 6 Input Channels to 6 Output Channels
- Low Impedance Outputs
- Voltage Indicator LEDs
- Multiple amplifiers easily supported with no loss of signal strength

When it was installed in my C5, you could pause the iPod, turn the volume all the way up ... and there was not a hiss or sound at all ...

Fasthotrod

I guess I don't follow you. How is it that an iPod can 'overpower' or 'step on' a stock head unit and create noise and buzz? Assuming that a person sets up their system correctly, this should never be an issue.

Just how much interference do you have in your car? What amplifiers are you running that can take advantage of an unbalanced input with that high of a voltage? It says in the Matrix manual that, "Most amplifiers cannot handle input voltages over three volts without clipping." and while I have seen some that can handle five volts or more, I'm curious as to why you think this is needed for your system?

Which leads me into the question I asked earlier regarding balanced signals... RCA connectors are normally considered unbalanced, unlike TRS or XLR connectors that are considered balanced. Normally, this means that the signal is sent on the center conductor of the RCA cable, and the outer shield is simply a ground/drain connection.

If you have an RCA style connection that is considered 'balanced' then you essentially have two signals on the wires: The inner wire is the main signal, and the outer wire carries an inverted signal that the amplifier uses (with a differential amplifier) to cancel out any noise. (Assuming that your amplifier has balanced inputs.) The chassis ground is the third 'wire' in this setup, much like the three-wire TRS/XLR style connectors in that regard. More info here.

If your HU is an unbalanced output, and your amplifier has an unbalanced input, then using a piece of equipment in between with balanced outputs doesn't really gain you anything. (No pun intended.)

I read the spec sheets, and for your every-day type system with just a couple of amplifiers, I'm not so sure this is going to be of much benefit to your average person. If you needed the extra sets of inputs/outputs, and plan on driving ten or more amplifiers, then I could see a need for this... but if not, what's the point? If you are running a sealed box, then I doubt that you will have much need for a subsonic filter... but it's there, and could be utilized if desired.

As for the differential inputs, all that means is an Op-Amp based differential amplifier that is used in a lot of audio equipment. (It's basically the 'balanced input' that I was talking about earlier.) It looks at the signal and performs a comparison between the signals and any noise, and effectively cuts the noise form the circuit. Look here for more information.

In my C5 I run a simple Alpine HU with an iPod and an Xtant X603 amplifier, and I can do the same. Granted, my amp as a 'noise gate' which is nothing more than a muting circuit that rejects any noise smaller than the input signal... but that's to be expected with a quality amplifier like that.

I'm not trying to bust your chops here, but I have been involved in audio long enough to know that some companies like to make great claims regarding their equipment, and some people 'buy it' as gospel. Just look at how many people have purchased "monsterous" equipment that claimed to be the 'be-all/end-all' of high end audio... it turns out, most people can't tell the difference from a hearing perspective.

If you have a vehicle that is prone to noise, and your amplifiers can accept a balanced input and your HU doesn't offer it, then perhaps adding a line driver with a differential amplifier is the cure... but I wouldn't make that determination without doing a bit more research into the problem.

In the case above, he said that he wanted to use the MS-8 to "level out" the signal from the HU, and as I said before and pointed out in the FAQ, the low-level signal from the GM HU is already pretty decent and relatively flat. If it were me, I'd run a good amp like the Arc Audio KS 125.4 Mini:

To further simplify OEM integration the KS 125.4 mini uses a fully balanced input stage that is switchblade between speaker and RCA input. Simply plugging your stock speaker wires into the RCA's will supply a perfect clean signal to the amplifier and turn it on.

So in that case, a stock GM HU should work just fine in this application.

Turbo6TA

My GS had the standard Delco audio system and no-Nav.

I really didn't want to change the look of the upper console area with an aftermarket radio/HU, so I just kept my OEM radio. The sound is great, but maybe a good quality aftermarket radio would be better .. I just don't know. I am thinking that the pre-amp and the tuner in the OEM radio really isn't that bad afterall ... It's the speakers and the power amp in the OEM audio system that are the real problem.

Anyway, I just added an AOEM-GM24 adapter to the wiring harness that goes into the OEM radio, and then ran my RCA interconnects from the AOEM-GM24 to my 5-channel amp like in the diagram below. I used RCA Y-interconnect cables to split the rear speaker signal and send it also to the sub speaker input on the amp .... simple!




As far as the Trigger wire (turn-on wire) is concerned, all you need to do is find the white wire that is in your OEM radio wire harness (this harness will be attaching to the harness of the OEM-GM24) and strip some insulation off of it. Then attach a long 18 gauge wire to this and solder so it's a good connection. Then just run that wire back to your aftermarket amp to the connection that accepts the "turn-on wire" .... You DO NOT need to use either of the 2 blue and white wires comming out of the OEM-GM24 for the turn-on. In fact, I tried to use these blue and white wires and could not make the amp turn on.

.

Thrash

Well, we are on a single 14v power line with shared ground. The iPod runs at what 5v, so it affects the power. The Matrix boosts the signal power above all the other devices, so the signal is uber-clean, no clicks, no fades, no rumbles.


The Matrix feeds into the AudioControl DQXS, then leveled and out to my 2 ARC amps, controlling levels, crossover and EQ on each pair of speakers -separately. This setup was mentioned in Forum threads back in 2006 or so, and I researched it then conferenced with AudioControl engineers about all of it. Basically, sit in your car, play a song from your iPod, now press pause and turn the volume on your HU all the way up. Do you hear anything (usually hiss)? On mine it's the same as if it was off. That is what the Matrix line driver does, and is enhanced by the DQXS as well ... like I said, it is uber-clean. Might be over the top, but as far as I can tell it works like butter ...

okie08vette

Mark, as always a wealth of info I did not know of your audio past. Next vette night I would like to show you the system I put in "O2Sweet"!

WAwatchnut

Mark - it definitely sound like you know your stuff! Do you think for the average 2-3 amp installation, there would not be a noticeable improvement in S/N from the input to the amps being driven to the max voltage the amps can handle (with the corresponding reduction in input gain on the amp)? Of course I'm assuming that the "average" head unit supplies closer to 3v cleanly, most amps are designed for 5v inputs max, and the AudioControl unit were installed properly, closer to the head unit, and not at the end of the RCA run. Noise introduced in the RCAs, and the amp having to work with 40% lower input voltage, should definitely have an impact, shouldn't it?


I don't believe most amps have built in 'noise gates', so improving input S/N would be more important than in your system.