4 drivers with dual 2 ohm VC's wiring question.

[Kingdaddy]

Just got my other 2 Avalanche 18’s (thanks Chad for expediting) to add to the other 2 that are already wired in a series dual channel configuration (4 ohm per channel).

What do you guys prefer for your Pro Amps, I've never ran my Mackie 1400i on a 2 ohm load. I was thinking I would have a better output to input ratio, I currently will clip my BFD output well before my Amp output, would a 2 ohm load allow more output? In addition, how are you guys wiring 4 drivers with dual 2 ohm VC's?

Forgot, Mono 2/4 ohm vs. Stereo 2/4 ohm, any preferences?

[Brian Bunge]

Wire the VC's of each driver in parallel for a 1 ohm load and then wire the individual drivers in series to achieve a 4 ohm load. Then just run your amp in bridged mode.

[ThomasW]

If the goal is lowest distortion/lowest noise, then running the amp in stereo is the best option.

He has a relatively small room and is using 4-18"s, so he has reasonably high efficiency. Also since his IB drivers are excursion limited not thermal limited, he doesn't want or need tons of power at the ready.

[Kingdaddy]

I'm still confused on what I need to do, I dont want an 8 ohm load at the amp, my BFD outputs clip well before the amp outputs already (4 ohm). I need a diagram of a series parallel configuration that will give me either 4 ohm, either dual channel or single channel.

Anyone know where I can find such a diagram?

[PMazz]

Use the 4 speaker diagrams when wiring 2 DVC drivers. You'll either have a 2 or 8 ohm load for each channel.

Wiring Guide

Pete

[ThomasW]

If the BFD is clipping you need to turn down the subout level so your not over driving the Behringer. Also check which position the rear panel switches are in. Normally their run in the -10dBV postion.

With dual 2 ohm VC's there's no way to get a 4 ohm load and run the amp in stereo. The only way to get a 4 ohm load is with the amp strapped.

You wire the individual VC's in series that creates a 4 ohm/driver. Series the drivers in pairs = 2 -8 ohm loads. Now parallel the pairs of drivers. That creates a single 4 ohm load.

[Brian Bunge]

You wire the individual VC's in series that creates a 4 ohm/driver. Series the drivers in pairs = 2 -8 ohm loads. Now parallel the pairs of drivers. That creates a single 4 ohm load.

Thomas,

Same end result that I got, just from a different approach.

[Kingdaddy]

Thanks guys, I went with the dual channel 2 ohm version, couldn’t get the 4 ohm mono to come out right, I kept getting 6.5 ohm. Anyway I'll do some testing and see how it looks.

Thanks again.

[Brian Bunge]

How were you getting 6.5 ohms? You must have wired something wrong.

[Kingdaddy]

How were you getting 6.5 ohms? You must have wired something wrong.

I dont know, I had two different Fluke meters and they both read the same, I did as you suggested; parallel the VC's (1 ohm) then series the drivers (4 X 1ohm = 4 ohms). My meter was in series, one lead on the first drivers + terminal and the other lead on the last drivers - terminal.

[Bent]

an 8 ohm driver in paraqlell with two 8 ohm units wired in series could give that resistance - approximately...

[ThomasW]

Since impedance is a curve that's frequency dependant, using VOM to measure them isn't really accurate.

BTW That particular wiring configuration can have a negative impact on the drivers damping.

It's better to series the individual VCs, then parallel the drivers together. That doesn't mess around with the Qms. And that's why I suggested it....

There's a big long winded technical explaination for this, but I doubt I can get Jon to chime in and type it due to his current work schedule

[Kingdaddy]

Since impedance is a curve that's frequency dependant, using VOM to measure them isn't really accurate.

BTW That particular wiring configuration can have a negative impact on the drivers damping.

It's better to series the individual VCs, then parallel the drivers together. That doesn't mess around with the Qms. And that's why I suggested it....

There's a big long winded technical explaination for this, but I doubt I can get Jon to chime in and type it due to his current work schedule

Yes you did tell me this over at the Cult, it makes sense, but I was strapped for time so I went with what I know and with your recommendation of using dual channels to cut the distortion a bit, so series VC's and paralleled each pair of drivers for 2 ohm, works fine. The 50Hz dip gave me fits though, all I could do is move it to 84Hz then I ran out of EQ bands. I also found a Subwoofer switch on the back of my Mackie 1400i amp, switched it on and set the switch to 63Hz and re tested, very strange readings, they seem much moor linear now but an average of 6db’s higher, no measurable roll-off after 63 Hz either (probably my boost from the PEQ or room gain). Anyway I’m goanna try to re-set up the subs with the amp in this mode, seems to have much more head room with the internal crossover turned on.