question on setting up 2 amps - PeachParts Mercedes-Benz Forum

greasybenz · #1 07-17-2006, 04:30 AM

OK here is the deal, i couldnt get the damn kicker 5 1/4 speakers to fit in the dash. So i stuck them in the back and put 4in pioneers in the dash instead.

Now the audiovox 4ch amp was overheating and playing engine noise so i gave up on it. Bought a jensen 4ch amp 600w dont know the RMS but can care less as they are smaller speakers. Works great! but i run into another problem.

The sub amp and the 4ch amp are connected with a equalizer. Problem is, that i cant get the bass i used to get when i had the sub amp connected straight to the radio rca outputs.

I assume im getting less bass because of the EQ even though i have the amp at full and the equalizer at full. Is there another way of connecting these two amps without a loss in bass?

bfisher · #2 07-17-2006, 07:51 AM

Does your head unit (or maybe the EQ) have a subwoofer output? Use that instead. Somewhere you need a low pass filter for that sub... else you are sending full range to the sub which it probably can't handle properly (wasting amp power plus muddying up the sound). It's possible your sub amp has a filter on it - if so make sure you have it engaged.

just my first thoughts...

Zeus · #3 07-17-2006, 10:19 AM

Does one amp have an RCA output capability? Decent multi-channel amps should have an RCA output, so you can daisy chain another amp to it. I've got two amps running in my car. A 4-channel to handle my car speakers and a 2-channel bridged amp running my sub. RCAs from head unit go into the 4 channel amp and this amp is set to HP and has a set of RCA outputs. I connected the outputs of this amp into the inputs of the sub amp and set it to LP.

greasybenz · #4 07-17-2006, 06:11 PM

Hmm, this is all a little confusing. BUT yes the EQ has a subwoofer output where the subwoofer amp is connected. The head unit only has one rca output the other is a aux input for ipods. Its a lanzar VBD400MP deck. The EQ is a targa that used to be run my fathers amps in his 4runner.

The 4ch jensen amp does have outputs and the 2ch boss amp running the subs has an output as well. Would it be possible to daisy chain these two amps as youve done yours?

bfisher · #5 07-18-2006, 07:57 AM

Sounds like it. Does your sub amp (Boss) have a low pass filter?

If yes, I'd try running EQ to the Jenson amp to the Boss amp (with LP on).

If no, I'd try EQ to both Jenson and Boss. Use normal RCA out on EQ to jenson, Use the sub out on the EQ to the Boss.

Zeus · #6 07-18-2006, 08:57 AM

Yup, what bfisher said. To simplify it even more -

(1) - Headunit RCA goes into input of EQ. RCA output of EQ (normal) goes into input of Jensen. Set Jensen to 'HP'. Normal RCA output of Jensen goes into RCA input of Boss. Set Boss to 'LP'.

OR

(2) - Headunit RCA goes into input of EQ. Normal RCA output of EQ goes into Jensen, set to HP. Subwoofer output of EQ goes into Boss, Boss set to LP.

Either should work. It depends on the amps and their capabilities. Many amps have a lot of features that let you tweak settings - i.e. bass levels, crossover frequencies, etc. If the amps are decent, I'd run the setup as per the first scenario. Also depends on the quality of the EQ.

The main thing in either scenario is to make sure you set the filters on the amps appropriately (the high pass and low pass)!

greasybenz · #7 07-21-2006, 08:28 PM

Ok i was messing around with it, set the boss amp to LP and the jensen to HP. But still didnt get the bass i used to get, i suspected the EQ since it is pretty old and outdated. So i bought a boss equalizer and now i get better bass responce, still not as good when i had the amp plugged in straight to the deck but good enough.

woodall33 · #8 08-11-2006, 12:21 PM

I would suspect the EQ as well. Chances are it is significantly cutting the RCA voltage. If you wish to keep that particular EQ, then I would strongly suggest getting what is called a "line driver", which will basically boost the RCA line voltage to whatever you desire. With a small entry level type line driver, you should be able to step up to say, 4 volts, and you will get a dramatic improvement. Of course, you can always replace that EQ with something newer that already does a 4v signal. Also, you could go all out and get something that pumps out as much as 7 or 8 volts, but I doubt that Boss amp would be very happy with that.

I think your problem is at the RCA signal though, particularly with the EQ not being "gutsy" enough to do what you are wanting.