Skater

Having read this thread again recently, it appears that the piece of kit I need is the Soundgate LOCB.2 converter that will allow me to take the outputs from the head unit and convert them to RCA inputs to my aftermarket amplifier. The problem is I live in the UK and I can't find a supplier. There are a number of on-line suppliers in the US but none on them seems to export to the UK.

Anyone know how I could get hold of an LOCB.2 or an equivalent device (with the same quality of course!)?

rkostolni

I am adding a sub and amp to my RX-8 this weekend, so I have been doing some research on where is best to connect the amp at. I contacted Bose, while the technician would not suggest a location, he did tell me the bose amp is full range, but does add equalization to the signal. Also, he believes the signal between the HU and amp is just a line level signal, and is not differential.

This equalization is why so many users are getting poor sound when tying into the speaker level wires. I think the pre-amp signal before the bose amp should be investigated more. Only one user has experienced a problem with this, and his problem could have been totally unrelated!

rkostolni

Okay, after a little more research, I have decided the Bose Tech was wrong. I believe the inputs to the Bose amp are differential. Going to try to scope them this weekend to finalize, for now I will assume they are.

My question now is what is the best way to get around this. I am also fairly confident that the Bose amp does do some sound processing thus changing the frequency response of the output. So probably not a great idea to tap lines post amp. Could tap the lines pre-amplifier, but the level there is supposidly very low, and so this will require the gain to be maxed out, and may still be too low to allow maximum output from the aftermarket amp.

I found a soundgate LOC that has a line driver built in that doubles the voltage, but it is $100, I would rather not spend this if I don't have to and since my jl amp has speaker level inputs I would rather use them if possible, or at least just buy a cheaper $30 standard LOC.

What is everyone's experience, how have most people interfaced to the stock system?

ScudRunner

I too would like to know the answer to this question. It doesn't seem to make much sense to me.

CactusGeorge

The solution that I finally settled on was expensive, but it works very well.

Some amp manufacturers, like Xtant and Zapco, offer differential input solutions. I went with an Xtant amp because the diff inputs are built into the amp and it was less expensive than the Zapco solution.

The Bose HU puts out plenty of voltage to drive the Xtant, and there are no noise problems.

BomberNYC

posting to make picutres appear

Dylwad

Cactus,

Could you be a dear and tell me where you tapped the input to the xtant at? do you have to run the xtant input balanced enabled?

what setting is your input db jumper at?

Im not sure if im having issues with the amp or the LOC converter's ive tried.

Thanks,

Dylan

unpocoloco

I've got the stock sound system and plan on adding a modest 4 channel amp in the trunk, and some better speakers. Nothing too fancy.

Okay, so my plan is:
1. Head unit -> level converters. This provides two RCA outputs for the fronts, and two RCA outputs for the rears.
2. Level coverters' RCA outputs -> RCA extension cable -> amp.

What is a good length of RCA cable to get me from the head unit to the amp in the trunk? I'd like to get enough cable so the installation is not hampered by too little cable (esp. since I'm ordering online and it'll be hard to return I'm sure), but not get much more cable than I need for several reasons. One, more cable typically means more signal degredation and more possibility to pick up noise. And two, anything even of medium quality is frickin' expensive!

Think 12 feet will be enough? (too much/too little?)

Thanks!

unpocoloco

Whoa! I take it back. The Monster 16' cable is actually cheaper than the 13' (it is on sale). ( blink )

Still, what I said about signal quality stands. I know for my synthesizer I needed long cables to connect to my stereo, and the extra length plus cheap RadioShack-quality RCA cables made the sound quality absolutely terrible. I paid the price and got some better gold-plated, thicker, and much more expensive cables and it was a world of difference.

So I'm sort of sensitive to long cables causing problems...

DjAD

hey guys, ive read a lot in this post and others about "tapping" into the preamps, about tapping to the amplified etc...

in my case, my amplifier has a line-in and line-out, that you can do a passthrough (audiobahn). If i reroute the preout at the bose amplifier to mine, and then route my amplifiers line out to the bose amp, shouldnt it work, and not overload the HU? the audiobahn amp has a linear line in/out passthrough...

finally some stuff i got from bose, as controversial as the rest: they say that the HU is not bose, they only produced the speakers, amps, etc. i asked them now specifically what type of input they have, and hopefully the will come back to me.

Any ideas???

finally, from what i understand the RL/RR (preouts) inputs to the amplifier are the gr/or, bl/or, gr/red, fr/red with their negatives, and they are full range flat... So i can take it from there, right?

thanks

DjAD

hey guys, more input: i just received the email from bose, still not verifying if it is a differential or low level pre-amp signal. However, i got the correct pinouts, which seem ok on my side, and confirmation that they are not using the - signals at all on their amp (!?!?). At least that is what i got from their connection schamatics.

yeap, go figure, if it is really differential, why the heck was it meant to be differential, if they are not using them. hmmmmm... will wait for the rest of the answers of course.

Also, from what i got from them, the input range is up to 4volts rms, with imput ohmage up to 300 ohms. anyone knows the correct voltage of a normal preout /lineout?

and the usual of course "mazda and bose never meant and doesnt want you to have a sub..." bla bla bla ... aha... whazavantmetodo? :P make me one then!

anyways, lets see if they really come back to me with the last info.

any feedback, glad to hear about it... anyone else run the inputs straight into other amps? (wihtout loc?)

Hercules

To bump this thread and ask a question....

Why can't you just get a line driver, push the signal coming off the HU and send it off to the amp?

David Navone makes a line driver that is $20 that will take your speaker level inputs and output them to RCA -- essentially an LOC (i believe).

Please let me know your thoughts on this, as this is the route I'm going to try to take... much obliged for any insight (mind you, I'm no car audio guru -- just extrapolating from this thread!)

DjAD

hi guys,
sorry for not posting earlier:
the guys put a line driver instead of going straight to the head. They didnt want to take the rist, even though BOSE did send me the whole configurations etc, and they were pretty sure that the signal was straight forward to get.

I was thinking to put my extra amp in the middle, and then jump from the output of my amp back to the bose amp. The response is pretty good, but like others i did notice imprefections, i.e. small delays, or bass not as clear or responsive as it should be. But cant do anything about it i guess.

as for the bass itself, sounds pretty good when wired from the rear speakers. had no problem, i regulated the low pass filter, and sounds pretty clear and deep. Could sounds better if it was on RCA, but dont want to risk it. Besides, were getting in the "family" business now, so i wont be able to enjoy it at full blast anyways with my wife (and kids in the future) in the back of the car.

have fun

yenphi

Now this time I will do this: buy Infinity Basslink with 4 chanel amp, I will wire AFTER the bose -amp speaker wires to 4 CHANNEL OUTPUT LOC then to Basslink, from Basslink I will connect 2 channel to original speakers and ALSO 2 channel to 2 New speakers I will put in the back center console (between 2 rear seats). Anybody have any idea about this setup? please let me know.

romancetech

i have an extra complete oem bose system if anyone needs it

Unhooked

so I read the entire thread and just want to clarify something. If I have an amp with High/Speaker level inputs do I need a LOC?

jakejacobson

iTrader: (4)

Sorry to revive such an old thread, but I wanted to ask the same question.

Was thinking about this amp http://www.crutchfield.com/p_500MRPM...ures_and_specs

It says it has the speaker input so no LOC needed?

paulmasoner

iTrader: (1)

if you have a Bose system, wrong. you'll need a LOC. the signal from that system is not normal speaker level signal.

if you have non bose, i dunno. but all this info was posted/discussed/debated/and settled years ago in these threads

xShinka666x

definitely get an LOC, it sounds horrible with the speaker level on the bose system in my opinion

paulmasoner

iTrader: (1)

more importantly it can and will eventually destroy stock components if you dont use one

jakejacobson

iTrader: (4)

Got it thanks. Sorry for the noob question, but how exactly can you tell if you have a bose hu or not? I've been looking around and can't really tell the difference without taking the hu out again. All I know is my tweeter covers say bose.

xShinka666x

doesnt matter, youll want to tap the wires in the trunk as its easier to get to and wont require a long rca run

paulmasoner

iTrader: (1)

then you have the bose.

paulmasoner

iTrader: (1)

not what was being asked....