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Discussion Starter #1
I was made to wonder about wiring together combos of subwoofers with mixed voice coil resistances while checking wiring diagram websites.

I wondered if amplifiers with headroom to run at lower ohms could add subs to 'match' the resistance of 1 or more other subs already there to take advantage of more power at lower ohms.

Let's take my N4 for instance. I run a dual 1ohm sub on it to get the amp to run at the 1000w level (using stated numbers from manufacturers just to simplify) so I run this sub at an effective 2 ohm load. If I were to add two more subs, say 2 dual 2 or 2 dual 4 ohm subs, and wire them so the newly added pair were an effective 2 ohm load then paralleled the pair in with the single sub already running at 2 ohm would it drop the effective load of what the amp would see to 1ohm or would the differences in speakers change what the amp sees in the end?
 

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If the efficiency and ohms of the subs are identical to the original matched pair, very little should be effected. The sub response however will be different.
 

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I wondered if amplifiers with headroom to run at lower ohms could add subs to 'match' the resistance of 1 or more other subs already there to take advantage of more power at lower ohms.

would it drop the effective load of what the amp would see to 1ohm or would the differences in speakers change what the amp sees in the end?
To get the most out of the amp, always run the channel(s) at the minimum impedance. Whether that's 1,2 or 4ohms. Rule of thumb. Understanding resistors in parallel, yes, adding 2ohms to 2ohms brings the load to 1ohm. That's called r-T. Total resistance(impedance).
Now as long as you r-T is not lower than the minimum rating of the amp, you can run as many speakers as you want. Question should be, how many speakers should you run? That's when matching RMS ratings comes into play.
 

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If I understand your question, are you asking, if I have an amp that is 1000 watts into 2 ohms and I run a single 2 ohm sub to it, what happens if I then wired in 2 4 ohm subs wired in parallel to present another 4 ohm load? If thats the case then you should be aware that the speaker with the lowest impedance will draw more power from the amplifier than speakers with higher impedances. Use the above formula (the 1/impedance one) to figure out what your total impedance will be.
 

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If I understand your question, are you asking, if I have an amp that is 1000 watts into 2 ohms and I run a single 2 ohm sub to it, what happens if I then wired in 2 4 ohm subs wired in parallel to present another 4 ohm load? If thats the case then you should be aware that the speaker with the lowest impedance will draw more power from the amplifier than speakers with higher impedances. Use the above formula (the 1/impedance one) to figure out what your total impedance will be.
if that were the case then the single 2 ohm sub would get the same power as the (2) 4 0hm subs wired to 2 ohms would. its not technically getting more than the (2) subs would, it would be an even split. (although the single sub would have to handle more since it is getting the entire 1/2 of the amplifier)
 

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if that were the case then the single 2 ohm sub would get the same power as the (2) 4 0hm subs wired to 2 ohms would. its not technically getting more than the (2) subs would, it would be an even split. (although the single sub would have to handle more since it is getting the entire 1/2 of the amplifier)
good to know
 

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Right if that sub getting more power was heavier duty. Otherwise with similar subs the powered up one will xmax sooner and all that. Most never recommend using dissimilar subs because of all those issues, it can change the response curve and other things, even just different size boxes. I have heard it work well, but it is not normal.

Lower ohms will get more power from your amp, if the amp can do it. More cone area will offer more dB but each additional sub divides the total power between subs. That means if you can use a sub with less powerhandling, those are usually more efficient but not always at the lowest frequencies.
 

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Along these lines, if you have two identical subs (say 4 ohm resistance each) and a two channel amp that is stable down to 2 ohms that can also be bridged, what will be the difference between running stereo two channels to each sub, or a bridged one channel to both subs wired in series?

What are the pro's and con's of one config. vs. the other (sql, spl...)
 

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Along these lines, if you have two identical subs (say 4 ohm resistance each) and a two channel amp that is stable down to 2 ohms that can also be bridged, what will be the difference between running stereo two channels to each sub, or a bridged one channel to both subs wired in series?

What are the pro's and con's of one config. vs. the other (sql, spl...)
I don't know if what you are saying has much relativity or whatever, it would be 2 channels running a 4 ohm load or an 8 ohm load to the bridged 2 ch.?
 

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Discussion Starter #11
Well in my case I have a FiQ sub that is 1000w rms and I wondered, when I had those 2 SA-8s if just one N4 would power them fine.

Even though the two 8s are rated 400w rms each, the N4 is a good match for two of them at 2ohm I'm thinking. And I have a pair of single vc 4ohm 10s that are 400-500w rms though I'm not gonna drop those 10s in my trunk anyhow lol. They're for my tiny Mazda b2300.
 

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I don't know if what you are saying has much relativity or whatever, it would be 2 channels running a 4 ohm load or an 8 ohm load to the bridged 2 ch.?
Sorry, big brain fart. For the situation when running a single, bridged one-channel I meant wiring the subs in parallel.

A. Amp in two channel mode, 4 ohm sub to each channel
b. Amp in bridged one channel mode, two 4 ohm subs wired in parallel


In any event, I did some forum searching on "parallel vs. series" and found some threads (http://www.diymobileaudio.com/forum/diyma-sq-forum-technical-advanced/35777-dvc-pros-cons-parallel-vs-serial.html)
 

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if you are running two subs that are 2 ohm in stereo vs running them in series to 4 ohm and then bridging the amp. power wise, makes no difference. as for the subs, they will get the same signal, since they will share a single channel. it is debatable if this does much. but if there were a slight difference left to right, it would be nulled out this way.
 
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