From what I've read on this forum, at the head unit I can tap:

1) low-level, pre-amp, left and right signals
2) remote amp turn-on

then why would I need this:

Pac Audio AOEM-VET1

I was thinking I could just tap the pre-amp signals and connect them to my subwoofer amp's low-level inputs. But the Pac Audio shows some kind of box, as if it's got some converter stuff, or a transformer in it. Is that a gimmick to try and scare people into buying their product and NOT simply tapping wires, or am I missing something here?

 

you need the aoemvet1 if retaining the stock radio

 

I am indeed keeping the stock radio, Dennis. But, if I simply splice onto the pre-amp signals at the connector at the back of the radio, that should be fine, because I wouldn't be interrupting anything in the stock setup, right?

 

very interested, just added the aux input to the stock head unit. Probably could hijack that signal but it would only play the base from my aux input. Not that i listen to the radio much anyway.

 

The C5 Bose system doesn't use standard signals. You will need to use the AOEM-VET1 in order to provide an interface that allows the connection of a standard aftermarket system.

The C5 Bose system is based on a modified Delco head-unit that uses pseudo-differential low level signals along with fully differential speaker level signals. The common signals are not standard and have a DC offset, so they cannot be grounded.

 

I can ground to the black wire, or the bare shield, can't I? I thought I read on here that several people have hooked up sub amps by tapping those signals. Am I mistaken?

 

 

If you could do it I would have told you yes you could do what your wanting to do.

You can not
as mentioned above the C5 radio and audio is not one you can use line out converters or doing what your wanting to do and do it correctly.

This is why i said you MUST use the aoemvet1

its really not that hard of a thing to do
you buy the aoemvet1 connect 1 wire and done
You have your preouts.

 

Well, I got the aoem-vet1, and everything is installed and working properly. I have an additional question for those that used the aoem-vet1 to connect to a sub amp:

Should I turn up the potentiometers on the aoem-vet1 to the max on the channels I used to feed the sub amp?

 

No one else has jumped in, but I would say NO... it's usually NOT a good idea to turn any audio equipment settings to FULL ON... unless your wanting to blow something... they give you range because for most applications somewhere near the middle should be sufficient...JMHO

 

Well, they're only pre-amp outs, so that won't overdrive the pac unit. Of course I would adjust gain on the amp. I would think i would want the full low-level output from the head unit. I can't see how the the pac could boosts anything, but I can see how those potentiometers can indeed provide an option to apply cut to the low-level signal.

 

Weirdly, NOT in the instructions, but on a sticker on the back of the package, in small print, it says, "... provides 2:1 gain and infinite attenuation". Right now, I have my amp at max gain with no distortion, but probably a raised noise floor that is going undetected due to the fact that I am powering a sub. Apparently, that little 8" vintage Kicker sub is capable of more than its rated rms, because the amp is a perfect match as far as numbers go. Although the amp does not get hot set at max gain, like you, 73Corvette, I would prefer NOT to run it that way. Since I also installed a remote output control ****, I could give the amp a little more headroom by upping the preamp out levels a bit. Unless someone thinks it's a bad idea, I think I'm gonna turn up the preamp gains to 3/4. Right now they are at 1/2, which is likely near Unity gain, or 0 gain. I'm sure those little potentiometers aren't exactly linear, but 3/4 should put me somewhere near 1.5:1 gain, and I can retune the amp and drop the gain a bit, so the amp won't be working so hard. I suspect it's not working as hard as it could be right now, since it's a 2 ohm rated amp and I'm only running it at 4 ohm, but I still don't like that the gain is pegged at max.

 

Ok... you just totally drug me out into DEEP water, I have NO clue about most of what you just said, lol... but, if the AMP isn't getting hot, clipping out , or distorting... I'd say it's set about right. For me setting EQ, Amp gains, etc.. is all about CLEAN... if I can get LOTS of volume with that being said, then it's a bonus... but, sometimes it's a trade off.. Clear, Crisp, Clean or just LOUD..

 

Ok, sorry for getting a bit too technical. I can explain the terms that threw you for a loop, if you like, just let me know which ones.

In any event, I took the bezel off again earlier this evening. I'm getting pretty darned good at removing it now. I increased the output gain on the aoem-vet1 to just shy of 3/4, instead of 3/4 like I originally said I would raise it to. I believe it's now close to 25% higher than Unity, or 0 gain. To clarify, Unity, or 0 gain, is basically the unchanged level that the aoem-vet1 receives from the head unit. I'm amazed that that little device has actual preamps in it, because that's what it has to have in it to have the capability of increasing the signal it receives from the head unit.

While I was at it, I pulled the hvac control unit to see how much wire was behind the stereo, and turns out that once the head unit is seated you can pull the wires toward the driver's side and connect the aoem-vet1 from outside the console, which is what I did. I simply tucked the unit under the carpet on the tunnel up front on the driver's side. Now I can easily access it by pulling the carpet out from under the left side of the bezel upfront if I want to make any further adjustments.

As far as gain-staging is now, I now have more signal at the amp, still don't detect any noise or distortion, and even though I brought the gain on the amp down from max to 3/4, I have more headroom now. For example, before I was turning my amp remote volume way up on some types of music to get the lows to a level Iiked, but now the **** is only at 1/2.

For what it's worth, I, too, like sound quality, and I know from experience with pro audio equipment that you want to get the strongest signal possible from the source because it is cleanest there, which is much different than turning up amp voume to try to compensate for a low source signal. That would surely introduce noise, not to mention can damage components.

 

Looks like you are getting it figured out... nice write up. I know others will glean from your expertise and experience... Your still talking over my head but I get the jest of what your saying and I totally agree... I think
I bet it sounds AWESOME and good call on relocating the Vet- 1

 

I used the pre-amp section of the stock stereo to feed my JL 250/1 and 300/4 just fine. You need to grab the signal between the deck and the BOSE amp.

 

That's what I thought you could do! As you can see, I went for the aoem-vet1, just to be safe, and at $29, I figured it wouldn't be that much of an expense if I ended up getting it for nothing. In the end, I am glad I did, if only for the little bit of extra gain it's internal preamps provide. But, where were you earlier, when I initially asked the question?! :-)

 

Sorry man... haven't had a lot of time this summer. But I do now....

 

Does anyone happen to know what the frequency cutoffs are on the Bose system? In particular, where does the hi-pass frequency cut for the twiddlers, and where does the lo-pass cut for the door subs?

 

The basic crossover frequency of the BSP is 1 kHz. - Thats what I found.

http://www.caraudioforum.com/showthread.php?t=28494