Three 10" 4Ohm subs, wired in series or series-parallel?

[Nagamitsu]

Ok,
Here's something I am not entirely sure about. Let's say I have three 4Ohm 10" single coil speakers.

Do I wire them up in series, or series-parallel?

TIA

Tim

Edit:

Hmm, from what I understand currently, if I run them parallel, they should put 4Ohm to the amp. If I run in series, they put 12Ohm to amp (?) and run in series-parallel, it varies or uses the highest Ohm (if I mixed with a speaker with a higher Ohm).

[Nagamitsu]

Ok,
No big amp here, here's what I found in specs:

4 ohms @ 12/13,8 V 75/100 watts RMS
2 ohms @ 12/13,8 V 110/150 watts RMS
bridge at 4 ohms @ 12/13,8 V 220/300 watts RMS

If this is the case, my best/safest option might be to do series-parallel, so I could hook up bridged at 4Ohm.

If I run parallel, I think it makes it 1.5Ohm thereabouts (4Ohm divded by 3).

So I'm unsure about doing bridged with series-parallel, or run parallel on one channel.

Tim

[Nagamitsu]

Think I may have answered this myself. Sorry.

Thanks all!

Tim

[I Am An Idiot]

your only safe equally powered option with the amp and speakers you have is going to be a series connection. Granted your amp will probably not make a lot of power into a 12 Ohm load. You will not hurt anything if you connect one speaker to one channel and parallel the other 2 speakers to the other channel of the amp, But the speakers will not see the same amount of power. If you do it this way, you really need an enclosure with 3 separate chambers.

[team_innovative]

Ok, well it all depends on the stablity of the amp, meaning... what is the amps lowest omh load it can safely handle? I'll break down the connection loads for you. If you run all three subs in parallel the current ohm load will be 1. If you run all three in series-parallel the ohm load will be 4. As for running all three in series... that isn't possible to do. However you can run four voice coils in series. And if that were to happen the ohm load would be at 16.

[I Am An Idiot]

3 X 4 = 1.33 or 12

[team_innovative]

Originally posted by I Am An Idiot
your only safe equally powered option with the amp and speakers you have is going to be a series connection. Granted your amp will probably not make a lot of power into a 12 Ohm load. You will not hurt anything if you connect one speaker to one channel and parallel the other 2 speakers to the other channel of the amp, But the speakers will not see the same amount of power. If you do it this way, you really need an enclosure with 3 separate chambers.

This type of wiring setup is possible to run. So as far as it not being possible to run 3 voice coils in series(as I stated earlier) I stand corrected. However, running a setup such as that isn't an option that I would ever consider doing. Thus, anyone who understands resistance and how it effects the power and performance of an amp, would agree that running 3svc subs to a 12ohm load isn't an effective or practical application in any way at all. So that is why I stated earlier that it couldn't be done. Because in all reality... it shouldn't be done.

[tsmith1315]

Originally posted by team_innovative


Because in all reality... it shouldn't be done.

I'm not looking to start an argument, or to be condescending. I disagree with such a blanket statement.

A 12-ohm load will cause a bridged stereo amp to produce the same power as it would into a 6 ohm stereo load. That can be perfectly practical and effective, depending on the system and your goals. I've used plenty of 6 and 8-ohm drivers as single drivers per stereo channel with great results.

In reality, it's a perfectly fine option depending on the circumstances.


Likewise,
I *personally* would not consider running a series-parallel connection with an odd number of identical drivers. Power will not split be evenly among the drivers, and (unless I was trying to do some sort of band-specific augmentation) that would be unacceptible to me.

That's no to say it can't be effective, practical, or it shouldn't be done.


To the OP's question-
If this were my amp and 3 identical 10" 4 ohm woofers, I'd either:

1)wire them in parallel and see how long the amp would run an effective 0.67 ohm load before shutting down or smoking, or

2)wire them in series and deal with the power loss, or most likely

3)buy one more identical woofer and parallel two per channel

[luka]

you can't put 3x 10" on stereo amp... not any normal one... get sub amp stabil on 1R and connect all 3 in ||

[chris661]

From what I know, to find the resistance of the 3 in parallel, you need to write them as 1/R (resistance), add them together, then do the 1/ again, so

1/8 + 1/8 + 1/8 = 3/8

Therefore the resistance would be 8/3, or 2.6666666666 ohms, not 0.67

Which means the amp should be happy.