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Old 12th July 2007, 10:42 PM   #1
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Default Impedance help!

Hey I have a question if I have three subwoofer's all 4 OHM DVC and wire 2 of them into a 4 ohm mono(frop both to 2 ohms each then wire in series to get 4 ohm's and take the other one left and drop that to 2 ohms and wire the two 4 ohm mono and the single 2 ohm mono and wire those parrallel into 1.3 ohms mono........ok that said would all of them recieve equal power?
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Old 12th July 2007, 11:02 PM   #2
jnb is offline jnb  Australia
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No. You could turn them all into 8 ohms and put them all in parallel for 2.7 ohms and they'd get equal power.
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Old 31st July 2007, 08:41 AM   #3
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I've been in audio for nearly forty years but I don't understand this question nor jns's answer

How do you "wire" a 2 Ohm speaker into a 4 Ohm one or "turn" a 4 Ohm speaker into an 8 Ohm one (without using a transformer)?
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Old 31st July 2007, 10:21 AM   #4
jnb is offline jnb  Australia
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Hi ricobasso, DVC=dual voice coil

cheers
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Old 31st July 2007, 10:54 AM   #5
AndrewT is offline AndrewT  Scotland
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Hi,
I think from your description you have 4+4 DVC drivers.

if so then JNB is correct.

In addition, I don't think ultra low impedance gets the best sound from amplifiers. They play a lot better when not stressed as hard as a 2ohm or 1ohm load attached to them.

If your amp can drive a 1ohm load decently then it should perform well into 2r7 (8//8//8)
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Old 31st July 2007, 03:25 PM   #6
Svante is offline Svante  Sweden
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One could also wire them for 2 ohms and connect them all in series, ending up with a 6 ohm load. If the amplifier cannot take low impedance loads, this may be a better choice.

Wiring them for 8 ohms, and putting them all in parallel ending up with 8/3=2.7 ohms may be ok if the amplifier can handle it.

Also, one should remember that the impedance of a driver in a box may be considerably higher than the DC resistance in the "sub frequency range" (20-100 Hz). This may make he second alternative better than it seems.
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Old 31st July 2007, 06:57 PM   #7
Petriej is offline Petriej  United States
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Dual Voice Coil subs are pretty nice to let you have all those options. Depending on your usage of the drivers and the amplifier you have, it looks like your best bet is between wiring each driver's coils in parallel (2 ohm drivers) and wiring the drivers all in series for a 6 ohm load total; or wiring the voice coils in series (8 ohm drivers) and wiring the drivers in parallel for a ~2.66 ohm load.

Just like Svante said. Keep in mind what AndrewT said, the 6 ohm setup is more likely to sound better, depending on your equipment. But in either case, the drivers should receive the same power each.

Also, as Svante mentioned, in their intended box, the impedance may be very different. If you have the equipment and your amp can handle it, try both setups and make an impedance graph. If you like what you see and hear, then, success!
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Old 31st July 2007, 09:28 PM   #8
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Im curious what is the rating of the amp, both impedance and power? Also, how much power can the woofers handle? The answers to these questions determine the most appropriated wiring method.
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Old 1st August 2007, 10:07 AM   #9
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Another thing you should bear in mind is that series connected speakers can go unstable at high levels. Non-linear behaviour during high excursions leads to unequal impedances. I've seen two in-phase, series connected, woofers in the same box move out of phase with each other!

DVCs in series is OK, but series drivers can have problems.
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Old 1st August 2007, 08:40 PM   #10
Svante is offline Svante  Sweden
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Quote:
Originally posted by ricobasso
Another thing you should bear in mind is that series connected speakers can go unstable at high levels. Non-linear behaviour during high excursions leads to unequal impedances. I've seen two in-phase, series connected, woofers in the same box move out of phase with each other!

DVCs in series is OK, but series drivers can have problems.

Hmm, just wondering... How did you see this? Did you use stroboscopic light or something? The nonlinearities must have been really strong, and I wonder if the speakers were at all useful at these levels?
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