Mixing different impedances.

[chasw98]

I don't post much here because I don't have an IB........ yet. But now I have the chance to pick up some drivers cheap to end up with 4 Soundsplinter RL-p15's. The problem is that 2 of them will be 2 ohm dual voicecoils and 2 will have 4 ohm dual voicecoils.

I have done a search and cannot find any info on good or bad effects of mixing differing impedance amongst the same drivers. As far as wiring them I can use a seperate amp per driver if need be or some sort of series parallel for anything from a 3.2 ohm load to a 12 ohm load.

What are the effects, if negligible, of using differing voicecoil impedances? I have looked over the T/S parameters and understand some, don't understand others and want to know before I commit. Thanks for any help in advance.

Chuck



Dual 4 ohm

Qts: 0.447
Qes: 0.508
Qms: 3.728
Fs: 27.487 Hz
Re: 6.1
Ls: 5.303 mH
Lp: 6.268 mH
Rp: 12.39
Dia:
(% shift) 330 m
37.5 %
Vas: 148.8 L
Mms: 231.4 g
Cms: 144.8 u
Bl: 21.90 T*m
n0: 585.0 m
SPL: 89.67 dB
Sd: 0.0806 m^2
Xmag: 27.4 mm
Xmax: 24.6 mm
----------------
Dual 2 ohm

Qts: 0.333
Qes: 0.363
Qms: 4.032
Fs: 23.426 Hz
Re: 3.66
Ls: 5.236 mH
Lp: 7.277 mH
Rp: 10.46
Dia:
(% shift) 330 m
23.7 %
Vas: 163.0 L
Mms: 290.9 g
Cms: 158.6 u
Bl: 20.76 T*m
n0: 554.4 m
SPL: 89.43 dB
Sd: 0.0806 m^2
Xmag: 27.4 mm
Xmax: 24.6 mm

[ThomasW]

Hi,

You don't want to mix different impedance drivers on the same channel of an amp. There won't be an equal amount of power going to them.

So go with one driver/amp, or use the 2 ohm pair on one channel and the 4 ohm pair on the other channel. With input level controls you can match the output.

[chasw98]

Actually, I was thinking of using 2 amplifiers with a channel per driver. Other than that, are there any downsides such as in audible sound quality?

Chuck

[ThomasW]

If you isolated the drivers and did an A/B comparison, you could probably hear minor differences between them (primarily the 2 ohm being over damped in comparison to the 4 ohm). But any distance away from nearfield, they'll just blend together.