belly

Hi guys.
Looking for some advice. ^_^
I have bose system and I installed new system w/ 5 ch. amp by expert(13 year career) in local audio shop. So far, I am pretty happy with this system. The sound quality is ok and I also have fade and balance. According to installer, the signal has to be tapped between bose amp and rear speaker. But the problem is I hear a constant running hiss even the audio turned off or the volume is "0", I believe that it is because of post-amp signal and the installer confirmed that. Also, for me, the sound quality is ok but a little muddy and not constant. I mean that the balance/combination of high and low are inconstant. When volume is low, I hear more bass. When volume is high I hear more high...
After searching in this forum, I found that adding soundgate LOCB.2 before bose amp and sending signal to aftermarker amp. is only solution... I talked installer and he said that it is just like wiring new system and asking $75 for installation.
My question is adding soundgate LOCB.2 will remove a constant running hiss with audio turned off, just like stock audio system. And since all wires are already there, is it hard to install by myself? or is it worth of spending $75 for installation?

Any advice will be appreciated.
Thanks in advance.
Have a nice day.

Rotary Rasp

iTrader: (2)

The LOCB.2 will help a lot. The LOCB.2 has a built in line driver which means you need to install it directly behind the HU otherwise if won't be as effective and you will be amplifiing white noise. The line driver will help to overcome alternator noise by increasing the preamp voltage. You'll have to run 2 new sets of RCAs from the LOCB.2 to the amps, and remember that the 2 in LOCB.2 stands for TWO channels. You'll have to get at least two of them to do your car with 4 speakers and three of them if you want to keep the 5th channel. I have this unit and I swear by it; yeah, it helped my system that much. I hope it'll do the same for yours. Installing it is not hard, just be prepared to remove the radio and what ever is in the path to the amps because you'll have to run new RCA wires.

belly

djseto, Rotary Rasp.
thanks for good info.
I am attaching some pictures of my system I took today.
first of all, I have no idea when it comes to car audio, but i will try to describe what i heard from my installer.
He took the signal after bose amp. and send to signal to after market amp and signal goes to each speakers. So, I just thought that replacing bose amp to LOCB.2 will clear hiss/white noise and will give clear signal to after market amp and I don't really have to disassemble HU since I just replace them in trunk.
But according to your post, I have to put HU out and install behind of HU.

Is it possible to just exchange bose amp to LOCB.2 in trunk? and any side effect? if it possible, could you elaborate how to? Can I just use 1 LOCB.2 since I have never used fade and balance function anyway or I better keep 2 LOCB.2 to keep 4 CH. as you said. I may loose fade function from HU, but sill can control fade by gain function on after marke amp. (I have saperate gain control:front and rear)

hopefully, pictures help...
By the way, I have Boston accoustic GT-50, MBQuart DTC169, Focal 165cv, ID nx30.

Thanks.

belly

more pictures

belly

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belly

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Rotary Rasp

iTrader: (2)

In short- Yes, you can do that but it dampers the surround sound effect.

Rotary Rasp

iTrader: (2)

Bad idea. It will work however, since the LOCB.2 is also a line driver you will be amping a weak signal. The Bose preamp is very weak to start with and by doing that you'll being amping a weaker signal. Line drivers are not repeaters, they do not recreate the signal, they only amp it. Therefore a poor input signal will only create a worse output signal. You'll also have a better chance of over coming ground loops and whine by installing it behind the HU. I'll see if I can get a picture of where I installed mine.

irfan

if you were to replace the speakers.. sending the differential inputs directly into an 4 channel amp that accept differential inputs and then out to your new speakers shoudl work right? in other words, you wont be using the bose amp or speakers at all? if i was to upgrade thats the route i'd take.. with a mono amp chained into the new amp, for subs