So I bridged my 4 channel amp into 2 channel and am just running my front components. Playing rap, it sounds fine. I had tested just turning my balance to all front and it sounded a little cleaner, so I thought I'd give it a shot. However, playing rock music, it just sounds like something is missing. I'm assuming there are sounds that only come out of the rear speakers, different than what is coming out of the fronts? I took the front RCA cables, got splitters and ran them to the front and rear hookups. Then on my deck I changed the balance to all front, since the rear isn't going to anything. That was the correct way to do it right?
EDIT I misread. You need to split the front RCA signal and connect them to both sets of inputs on the amp. Rear RCA lines are not used.
But NO, the sound from front and rear speakers is not different. Exactly the same. All standard audio systems are 2 channel stereo, a right and a left channel. Left channel audio goes to front left and rear left speaker, right channel audio to front right and rear right.
What speakers do you have for front stage? what speakers for rear?
I'm willing to bet the raps sounds fine since you are pretty much just getting bass and highs. But w/ rock, you will have a more prominent midrange. So, having something like a pair of 6x9's for a little more mid in the rear sounds better.
All in all, you are likely just lacking mid-range from your front stage.
It seems that all my sound is coming from my right side. When I turn the balance to the left, the volume goes down. When I adjust to the right it stays the same. It sounds weird because I'm not getting any left channel. I know I hooked it up right.. I split the front RCA cable right to the front and left to the rear.
If you properly split the right and left signals from the HU to the 2 channels on the amp, you should be getting equal power to both right and left fronts.
Try this. Get rid of the Y-splitters...just for a test. Put the Left RCA into one of your RCA inputs for your amps front channels. Do the same for your Right RCA and rear channels.
See if the sound is equal for the fronts then.
Makes sure your gain and crossovers on the amp are set accordingly.
Also, what 4ch amp do you have? Some amps have a 4ch/2ch option that internally splits the signal to allow for a setup like you are trying to create.
It's a RF 4004. I've got the button pushed in that sets it for 2 channel mode. It's never been ran bridged before. I'm going to try your advice and see if I can figure it out. My components you asked about are the 6.5 pioneer rev series, 60 rms.
the ONLY source that uses more than 2 channels in a car, is a DVD. for music, it's all 2 channels, so front and rear are identical. If you're missing something, it's probably midbass.
if you do want the rears back in the loop, then run front and rear pre-outs to the 4 channel amp. run the fronts on channels 1 & 2, in stereo (typical.) bridge channels 3 & 4, and wire the two rear speakers in series, and run them in mono, and fade toward the front on the head unit till the rears are barely audible. This will prevent destroying your soundstage and imaging up front, will still giving rear fill. You'll also want to use both the head unit and amp filters to create a band-pass filter for the rears, so they handle about 150Hz-5000Hz. Nothing above or below. This will prevent them from bottoming out, or being too bright and distracting.
That's pretty much the ideal way to run rear fill without doing a more complicated L-R setup with 20msec delay.
Thanks for all the great information guys. Always great advice. I believe on your page about rear fill glasswolf you were saying you really shouldn't run tweeters in the rear, so its better to run just mid bass drivers. I was thinking of getting a pair of components and just running the driver and not the tweeters. Then I could wire it in series and run them mono like you suggested. Sound good? What would you guys recommend for a good pair of mid bass drivers for the rear? Something around $100.
The advice on turning the amp back to 4 channel worked. I hit the button and it solved the problem. I believe if I was just to run the front RCA's to the front channel input, then select 2 channel mode, it may have worked as well as MS had recommended.
That's why I love dealing w/ 12v audio on a daily basis. You can pick up on simple things that the average joe would miss.
Actually, the trouble shooting thing I posted was to help test for the very problem my 'switch flip' method fixed. Your 2 right RCA's were just doubling over to from the amps front channels to the rear. So, when you faded to the left, you lost pretty much all sound.
. . . . . What vehicle do you have? What size speakers fit in your stock locations?
If your HU does not have time alignment, keep the y-splitters in place if you want to retain the ability to balance left and right.
By splitting the HU's front RCA out to the rear and front inputs on the amp, you effectively force those inputs to react as left and right rather than front and rear. With some 4ch amps, the inputs react as if your HU only has a single R-L RCA ouput. If you put your RCA's directly into the ch1-2 inputs and put the amp in 2ch mode, you may loss the audibility to balance L-R.
Of coarse that all depends on how the RCA summing/input/output works on your amp.
Best to just keep the splitters in for now. As long as you a happy w/ the loss of rear fill. You may want to run the rear speakers directly to the rear speaker outputs on the HU as MS recommended. That may allow for a little 'ambiance' given the much lower power output of the HU vs the amp.
It's a celica and my speaker size is whatever size lol. I took the advice of isolating the mid bass drivers and used 1/2" mdf to mount my drivers to. That alone gave me a huge increase in mid bass.6.5 was the factory sizes though, front and back.
I plan to sound deaden my doors eventually, which I know will also help with my mid bass. I was very happy with the improvement just adding the mdf did though. I went from almost no mid bass to feeling it in my chest now. I used to have 4 rear speakers, 6x9's in the rear walls and then custom fit 6.5's under the back hatch window. This was years ago, when I assumed more was better, so I had lots of rear fill. A month or so ago, I decided to take out the 6x9's since I know that a round speaker provides better SQ and to run just the 6.5's in the rear walls, which would also let them run at a 4 ohm load, that is also better SQ. Well, where the 6.5's had been in the rear window for years and years, I believe they became a little brittle and frail. The rear speaker behind the driver seat started making noise a few days ago. At low or high volume. I took the rear wall apart to make sure it wasn't rubbing something and its making the noise on its own. This is what lid me to think about just running my front components. I could either invest in a new pair of rear speakers, and do it right in the process, or just run my front components. My 6x9's I took out are the same exact series/model of speaker as the rest and are in mint condition. I could run them in my rear walls, the only thing there is, they're coaxial and I've read its not ideal to run tweeters in the back.
