2007AcuraRL

I've seen a bunch of posts where people are using the line output converter (LOC) off the speaker outputs of the head to drive amps. While I am not sure about the 2001 and earlier head units, The 2002 acura head unit has a line out loop and goes from the head, to and outboard Bose eq module and then back into the head.

I would prefer to use this line signal out of the head and BEFORE it goes to the bose eq as 1) its gotta be cleaner than amplifying the speaker level outputs (which are already being introduced to impurities inherent in the built in head unit amp) and 2) the bose eq was designed specifically to tailor the sound to the Bose speakers, so its definitely not a flat signal.

Now for the question --- has anyone hooked up amps this way? I understand that the bose eq also boosts the signal level a bit, so when you bypass it, the levels out of the head unit are lower, even if you were just using the LOC off the speaker level wiring.
I can probably find a signal cooker that will increase the gain to an acceptable 3 or 4 volts out, but i just wanted to know anyone else's experiences (and suggestion of what line device to use) in this configuration. I am also concerned about engine noise since the line out to the bose eq is just straight wire and not shielded cable.

Give me some guidance here please.

Brewboy

I have bypassed the EQ for my front stage and it is definitely worth doing if using aftermarket speakers with or without a new amp. I have no problem with the signal voltage, as my amps are gained at about 1/3-1/2. I would try it without a 'signal cooker' first, less in the signal path the better as you have said. I think you will find it isn't necessary.

2007AcuraRL

Thanks for the reply Brewboy. Tell me how did you you get the signal to the amps in you configuration? Is the signal out of the head a low level signal at that point and did you simply solder RCAs to the wires coming out of the head and ground the outer shielded core to chassis? or do you have one of those amps that have both hi and low level inputs? Again, I am not interested in using the line level speaker outputs which i know would require a hi to low level adapter. I need RCA low level signal because I am going to go straight into a Pioneer DEQ 9200 DSP module first and then out from there to the amps. I am also concerned about engine noise problems that might occur.... would you please elaborate a little bit on how your configuration is?

When I put the question to the folks at Soundgate.com, they suggest using their LOCB module. You are suggesting one isnt needed.....

Brewboy

Well, the HU is not the best for adding to because you will have to pick a R+, L+, COM (shared common, yuk!). There are a few ways to do this I suppose or even a BLD, but I would try the cheapest way first to see if your satisfied. This has worked for me. What I did was take (2) twisted pairs about 4"-5" long and solder a RCA to each end (a female is best if you can find one, if not, no worries). The other ends of the twisted pair get soldered (or jumpered if you prefer) to the wires between HU and EQ. The wires you soldered to each of the RCA pins go to the R+ and L+, respectively, and the two wires soldered to the RCA barrels get solder together along with the COM. If you didn't use female RCA's then buy a dual RCA splice (female-female) and plug it into the new RCA's. The other side of the splice you can plug in a high quality shielded RCA patch cable then off to your amp(s). In short, you need to Y-off the COM to share it between L and R. The twisted pair is only a few inches long to avoid picking up noise so you'll need a patch cable to reach from the HU to your amps. I have no audible noise to speak of but the shared common is not the best. I do have a circuit that was designed by a long time amplifer engineer/designer designed to use the L,R,COM as inputs and output a psuedo-differential-balanced (L+,L-,R+,R-) output for an amp. If you have the time and software to analyze and tweak it, I'll pass it along, or maybe somebody else here can work it. I used UTP but you could use shieldedTP and solder a wire to both shields then attach it to a HU gnd point, but only on one cable end, otherwise you'll have a gnd loop. Good luck.

2007AcuraRL

One more question, Brewboy: since i posted the original question the other day, someone else told me that the outputs from the head to the EQ are not variable but rather are fixed. (meaning they dont respond to the volume knob. I take it from your post that this isnt the case and they are actually variable? BTW, just to make sure, is your head unit from the 2002 model year of the car?

Brewboy

I have no volume problems. In fact, I only bypassed the EQ for my front stage with the rears still being powered and EQ'd via the HU although I fade everything forward. I am referencing a 2000 TL. I don't think it would be any different though. Ron (StreetEffectz) may know since he installs in many TL/CL's. Send him a PM concerning your year. Good luck

plahaise

Brewboy, do you have nav? If so, how did you get around the problem of the directions cutting in (and not being able to hear them) with the new amp setup? If not, how do you think the amp should be rigged into a nav system?

By the way, I just got my 03 tls/nav on Sat. I'm still grinning...