Anyone know their way around the sound system?

[figure1a]

I've got a 2001 X5 with the DSP sound system. Sounds pretty good but the sub woofers are terrible (muddy and hollow). The subs in the DSP system are rather unorthodox. I pulled apart the sub box and there are two 6.5" subs in there each with two voice coils each rated at 8ohms apiece--that means there are 4 sets of speaker wires going to the box expecting to mate up to four 8ohm connections. There are no after market 6.5" subs with those specs. I want to replace them with a JL 10W6 or maybe 10W8 (I'll make a new enclosure). I want to use the amp power from the DSP system. For anyone who has changed out their subs or knows the specs of the DPS system my questions are:
1) The speakers are rated at 8ohms, but do you know what the amp is rated at? I'm hoping it's 2 or 4 ohms and the speakers are just overkill. That would give me some better speaker options. If no one knows, does anyone know how I could measure what the impedence of the amp is?
2) Since there are four sets of speaker leads going to the sub box, could I bridge the four pairs into two and power a new sub woofer? What would this do to the impedence load of the amp?
3) Could I just not use the power from the leads, extract the high level signal into a low level signal and add a new amp to power my new subwoofer? Would just leaving the existing leads not hooked up to anything overheat the DSP amp or would the DSP amp be "smart" enough to know there is no load on those speaker wires and not overheat?
4) Anyone else done any other thing I haven't thought of to add a better sub to the DSP system?

[ponchonutty]

Originally Posted by figure1a

I've got a 2001 X5 with the DSP sound system. Sounds pretty good but the sub woofers are terrible (muddy and hollow). The subs in the DSP system are rather unorthodox. I pulled apart the sub box and there are two 6.5" subs in there each with two voice coils each rated at 8ohms apiece--that means there are 4 sets of speaker wires going to the box expecting to mate up to four 8ohm connections. There are no after market 6.5" subs with those specs. I want to replace them with a JL 10W6 or maybe 10W8 (I'll make a new enclosure). I want to use the amp power from the DSP system. For anyone who has changed out their subs or knows the specs of the DPS system my questions are:
1) The speakers are rated at 8ohms, but do you know what the amp is rated at? I'm hoping it's 2 or 4 ohms and the speakers are just overkill. That would give me some better speaker options. If no one knows, does anyone know how I could measure what the impedence of the amp is?
2) Since there are four sets of speaker leads going to the sub box, could I bridge the four pairs into two and power a new sub woofer? What would this do to the impedence load of the amp?
3) Could I just not use the power from the leads, extract the high level signal into a low level signal and add a new amp to power my new subwoofer? Would just leaving the existing leads not hooked up to anything overheat the DSP amp or would the DSP amp be "smart" enough to know there is no load on those speaker wires and not overheat?
4) Anyone else done any other thing I haven't thought of to add a better sub to the DSP system?

Well, the sound systems in these BMWs suck. Trying to add things are almost impossible. You could try to just replace the subs but I doubt it will work. Those subs you have I am sure are very low in wattage. Adding a real subwoofer too it might be rough. I would find a single voice coil sub rated at 4ohms and also try to keep the RMS wattage as low as you can.