parallel/series help - AVS Forum
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post #1 of 22 Old 12-02-2012, 08:08 PM - Thread Starter
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I've got 4 separate sub enclosures with terminal cups. Each cab is 8ohms and I was running two cabs wired in parallel for a 4 ohm load and running my sub amp in stereo. Now...how do I wire the 4subs in series to create a single 8ohm load? TIA
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post #2 of 22 Old 12-02-2012, 08:18 PM
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unplug one red and one black from where they connect to the amp and connect them together.

now the signal will go from the red on the amp through sub pair 1, then through sub pair 2, then return to the amp on the black.

a 9v battery can be used to ensure that they all move the same direction when connected to a voltage.

a simple multi-meter can be used to ensure that the net resistance is what you are looking for.

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post #3 of 22 Old 12-02-2012, 08:46 PM - Thread Starter
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I'm still confused LT so maybe this can help you break down just a little bit more. Thx
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post #4 of 22 Old 12-02-2012, 09:12 PM
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does this help?

top is two drivers in parallel per channel.

bottom is two drivers in parallel seriesed.

i'm not sure why one would do that, but that is how it would work.

if bridging, make sure that you use the correct set of terminals and configure your amp for bridged mode.


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post #5 of 22 Old 12-02-2012, 09:46 PM - Thread Starter
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Yes! Thx LT!
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post #6 of 22 Old 12-02-2012, 09:57 PM
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no problem.

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post #7 of 22 Old 11-16-2013, 11:16 PM - Thread Starter
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I've got a total of four 2 ohm cabs and would like to bridge them all together for an 8ohm load. Two cabs are wired in series for 4ohms per side. How do I wire in series to the other 2 cabs to achieve 8ohms?
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post #8 of 22 Old 11-16-2013, 11:27 PM
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if I understand you correctly, what you have now is represented by the top picture.

the bottom picture would be series wiring of all four drivers for a net of 8 ohms to the amp.


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post #9 of 22 Old 11-16-2013, 11:51 PM - Thread Starter
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Bam that's it! Good ol LT to the rescue. Thx as usual.
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post #10 of 22 Old 11-17-2013, 10:43 AM
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Could I ask why you want to do this?
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post #11 of 22 Old 11-17-2013, 12:13 PM - Thread Starter
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Right now with 4 subs per side I'm at 95db efficiency. I'm gonna rewire to be 98db and run my amp bridged so an even easier load and more efficient.
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post #12 of 22 Old 11-17-2013, 01:50 PM
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A good link to have when you are going to connect several elements.

 

http://www.rockfordfosgate.com/rftech/woofer_wizard.asp?submitted=true&woofer_qty=1&woofer_imp=3

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post #13 of 22 Old 11-17-2013, 01:55 PM
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What amp are you using? Going from 4 ohm per side to 8 ohm mono is usually considered the same. However, some amps are spec'ed a little better running stereo.
Where did the 3db gain come from?
Also, the amps I am familiar with are wired from red to red in bridge mode.
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post #14 of 22 Old 11-17-2013, 04:35 PM - Thread Starter
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Sanway FP14K, yeah I should have clarified I know the impedance presented winds up being same to the amp. The 3db comes from wiring the subs in series again (from cab to cab) so the amp should work half as hard. The subs are dual 2 ohm 89db a piece so four winds up at 95. Now from those four wired in series to the next four achieves another 3db.
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post #15 of 22 Old 11-17-2013, 06:24 PM
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I'm not familiar enough with the clone to know if you have an edge running stereo or bridged. By going to bridged mode you have doubled your voltage. By rewiring your drivers you are also doubling your impedance. Therefore, you have the same current, and the same load to the amp. Unless I'm missing something here, if you have not added power or added drivers you're basically in the same place as you started.
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post #16 of 22 Old 11-17-2013, 08:32 PM - Thread Starter
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I was under the impression that an increase of 3db in sensitivity (98) would result in half the amp power required to reach the same SPL of a load at 95db. Is this not the case?
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post #17 of 22 Old 11-17-2013, 09:09 PM
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Again, I ask where did the extra 3DB of sensitivity come from? Have you doubled your drivers or have you doubled your power?
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post #18 of 22 Old 11-17-2013, 10:00 PM - Thread Starter
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Doubled drivers from 4 to 8.
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post #19 of 22 Old 11-18-2013, 10:09 AM
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Ok, I'll start by apologizing if I am not seeing the picture here. I've been up all weekend with a sick 2 1/2yr old. Not much sleep to speak of.frown.gif

"I've got 4 separate sub enclosures with terminal cups. Each cab is 8ohms and I was running two cabs wired in parallel for a 4 ohm load and running my sub amp in stereo. Now...how do I wire the 4subs in series to create a single 8ohm load"

I read this as 4 total subs at 4 ohms per side on 1 amp. LTD02 showed how to make this an 8 ohm load.

"I've got a total of four 2 ohm cabs and would like to bridge them all together for an 8ohm load. Two cabs are wired in series for 4ohms per side. How do I wire in series to the other 2 cabs to achieve 8ohms?"

I read this as 4 total subs at 4 ohms per side on 1 amp. LTD02 showed how to make this an 8 ohm load.

"Right now with 4 subs per side I'm at 95db efficiency. I'm gonna rewire to be 98db and run my amp bridged so an even easier load and more efficient."

I read this as 8 total subs at ? ohms per side on 1 amp.

"Now from those four wired in series to the next four achieves another 3db."

As it stands from the two examples provided by LTD02, if you wire these in series you will have a 16 ohm load. I might be missing something obvious, not sure my reading skills are up to par. Sorry if I'm confusing an issue that you already have worked out.
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post #20 of 22 Old 11-18-2013, 10:24 AM - Thread Starter
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As LTD02 drew up the top diagram is exactly how I wire my boxes currently. Each of 4 boxes contains two subs as they are dual opposed. I think I see the confusion because in the wiring diagram only 4 subs total are shown.
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post #21 of 22 Old 11-18-2013, 04:40 PM
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gpmbc, the sensitivity of the drivers doesn't change based on how they are wired up. the system will still provide the same spl per watt in series or in parallel.

a driver that has 95 db 1w1m sensitivity when dual 4 ohm voice coils are wired in series for 8 ohms will produce 101db when wired in parallel and hooked to the same amplifier setting, but that is because in parallel the driver is 2 ohms net and the amplifier is producing 4 watts of power.

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post #22 of 22 Old 11-18-2013, 10:24 PM - Thread Starter
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So in my scenario, is there any benefit at all in bridging the amp? I thought less power would be required based on a more efficient load (higher sensitivity)?
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