I have a RSX sub connected to the sub out of my HU which was working fine but when I switched out the HU for a new one, I can now barely hear the sub.

It's still working since I can hear some difference if I turned the sub out adjustments on this new HU, but it's really really low. I have no idea why there is such a big difference. Actually it was a bit too loud compared to the rest of the speakers, on the old HU which had not sub out adjustments. I turned off the low pass filters, and tried changing the sub out volume, the volume adjustment made some difference but still really low even when I turn it all the way up. I also tried switching the wires thinking it might be a phase issue, no difference either.

Any ideas, hints?? Thanks guys

 

What HU do you have?

Perhaps you can just adjust the 'level' of the sub?

I have a pioneer p880prs and my output is lower then I expected it would be too... *shrug*

 

some radio's have 2volt pre-outs rather than 4v pre-outs... if your dying for the extra power get a line driver.

 

Yeah I tried adjusting the sub level from the HU, I can hear the volume go up and down, but even at max level, it sounds weaker than the stock speakers.

The interesting part is, my old HU has 2V preamp outs and my new one has 4V preamp out...

imdarkrider, by line driver, do you mean like a LOC?

 

LOC has the same concept. werid that you getting worst sound with the higher output.

 

So what is your new and old headunit? kinda important information

 

Actually, I just noticed that the sub is making a whining/humming noise, similar to when you overload an amp with two speakers in series, etc. Could it be the 4V pre-out? Is there a way to reduce the 4V pre-out to a 2V?

Re: the HU, old one was a Blaupunkt Monterrey MP35, new one is a Sony CDX-GT805DX

 

you might want to run a search on the RSX sub. apparnetly there are issues with it which you can fix.

 

Yeah, I've already looked at the old threads, I think there was a couple of instances of ppl having low output from using the 4V preouts, while other had success with preout (but didn't specify 2V or 4V).

Is there anyway I can decrease the output voltage to 2V from the 4V output??