It sounds to me like all the bass is going to the lower speaker in each door. Very little seems to be going to the 6x9s in back. Anyone else get this impression?

 

There should be bass going to the 6x9's. The crossovers are built into the hifi amp. Even though I replaced the back speakers I have my fader almost all the way forward as the backs can't hang with my fronts powered by an aftermarket amp.

 

Try setting the fader all the way to the back. I think you wont hear much bass. I've got a soundtrack to Mononoke-hime that begins with some big bass drum beats. Very little of that can be heard in the 6x9s.

 

strange.. I know when I first changed my fornt speakers without having changed anything else the front's definiately put out more bass than the backs but I chalked that up to better speakers.

 

I just tried going 100% forward, and back. Sounds about the same, but it seems the 6x9's in the back distort alot faster from the bass than the fronts. But they both seem to be getting the same signal. I have the Hifi, no mods. (YET!)

 

I tried the fader today with a Foghat tune playing, and got the same bass front and back. I have the HiFi option without modifications.

 

I'm just ditching the rear speakers altogether, no point for them IMO. Had a few "competition" setups that had no rear speakers, I love the way it sounds without them. The speakers are crossed over terribly imo, I've bottomed out the fronts a few times (whoops). Considering the stock stereo doesn't have time correction or anything, a signal summing interface such as pac pch8 or an audiocontrol lc8 would do wonders, then use the crossovers at the amp to do the trick, I know the front "bass" speakers are low pass, meaning the lows pass, theres no subsonic filter and no lower reduction so I think it would work well. I can draw this if this is confusing.

 

a96bimmerm3, I hope I am not the only idiot out here who was confused by that. More explaination would be much appreciated. What exactly would "a signal summing interface such as pac pch8 or an audiocontrol lc8" do for you? Where do they go in the audio chain? For those more-experienced in the car audio arts I appologize for the novice questions.

Pat

 

A "signal-summing" processor is used to take an audio signal that's already been broken up into several different frequency ranges by a factory crossover and recombine them into a full-range signal. They're really useful when your factory head unit has a crossover built into it that you can't bypass. The signal-summing processor would take the multiple signals from the head unit and give you one full-range signal that you could then send to aftermarket amps or crossovers so that you could set the crossover frequencies where *you* want them, not where the factory head unit is programmed for.

I don't know if this is true for the second-gen cars as well, but in the first-gen MINI with the H/K system, all of the crossovers are in the factory amp, not in the head unit, so if you want to change the crossover points, all you have to do is take the full-range signal from the head unit and feed it into an aftermarket crossover (or an aftermarket amp that has a programmable crossover built-in). You would have to ditch the factory amp, but if you're going to the trouble of changing the crossover points, you're probably going to want a new amp anyway.

So, for a system like the MINI's, I don't think you need a summing processor - just take the factory amp out, use the full-range signal from the head unit, divide it up with a crossover (either standalone or built into an aftermarket amp), and then run the split-up signals to the appropriate speakers.

 

Scott,
Thanks that is a great description and makes perfect sense. As MotorMouth pointed out in this thread, and I have read elsewhere, "the crossovers are built into the hifi amp". I was confused why one would need such a device in the R56. It sounds like you really don't.