Need Series & Parallel Combination Info

I am wiring up 9(nine) P212S4 subwoofers in my vehicle and I have looked everywhere trying to find information on how I should wire my subs. Series wiring gives me 36 ohms which is way too high. Parallel gives me .4444.... ohms which is way to low. Is there a site I don't know about or could someone here help me? Thanks

You need to think in multiples of three here. Here is how I would do this. I would break the subs into sets of 3.

Option 2 (series) = 12 ohm load Speakers wired in series Recommended Amplifier: Stable at 4, 2, or 1 ohm mono

This is a series circuit. Think of this configuration as one sub that has a impedence of 12 ohms. So what you have is three sets 12 ohms speakers. The next stage is to wire the three sets of speakers in a parallel circuit like this. Option 2 (series/parallel) = 4 ohm load Voice coils wired in series, speakers wired in parallel Recommended Amplifier: Stable at 4, 2, or 1 ohm mono

Now what you need to look at above is simple. Wherever it says 6 ohm, think of it as 12 and each speaker shown above is actually a group of three speakers, so nine in total. The amp that you will need is a big monster 2 channel amplifier for this task. Big, big, surfboard 2 channel amplifier for this application.

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Top Secret, I can tell you but then my wife will kill me.

You could also have three 4 ohm woofers in each group wired in parallel netting 1.333333 ohms (see below). Now wire all three groups in series . This will net a 4 ohm mono load (1.333 + 1.333 + 1.333 = 4).

Either way will give you a 4 ohm nominal impedance.

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the12volt • Support the12volt.com

When you go to the link the12volt showed you above, you will also see a parallel calculator next to the series calculator.  Use the combination of these two calculators to figure out wiring for any number of woofers.  Depending on your system design and power availability, dropping the total number down to 8 subs will give you some different available loads.  As shown above, think of any number of subs as groups of even amounts, so with nine subs you have only one choice - groups of three.

However you end up deciding to do this, draw up a wiring diagram to use.  Then place that diagram with the subs for future reference.

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

Ok. Got the idea now. The subs are Single voice coil so I did a combination of Series and Parallel. I got the pics of the van and the wiring diagram post at https://www.cardomain.com/ride/2329075/1
Check it out and let me know what you think. Thanks for all the help guys and hopefully this will be of some assistance to someone else in the future.

The wiring as you described on page 4 of that link is a correct series/parallel scheme.

But then you stated that the load amounted to 6 ohms.  These are 4 ohm subs, correct?  It is a 4 ohm load as forbidden and 12volt stated above.  Typo?

You currently have this 4 ohm load bridged to the Rockford amp for about 100 watts to each sub.  You wrote that you are using this setup until you can buy another T15002 amp.  My question is this:  how will you be able to incorporate a second amplifier with this group of nine subs?  If you've figured that out let me know how because I can't see the possibility.

Nice job with that FG baffle.

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

Sorry, typo on my part. 4 ohms is correct. As for the other T15002 amplifier, I will be purchasing another 2 for a total of 3. Three subs will be run off each amplifier. It's my first time messing around with any car audio set ups (wiring, fiberglassing, etc.) and I have gotten most of my information from right here and from friends. If there are any better ways to do this wiring that you guys know then it would be greatly appreciated. I tried to combine the information from the posts above and thats seemed to be the most likely setup that I could think of. Thank You guys for all your help and advice. It's been alot of fun and definately will be in the future. Let me know If I'm wrong on anything. Thanks

Those are 200 watt RMS subs, so three of them on an amplifier would like to have up to 600 watts.  Three SVC 4 ohm subs wire to either 12 ohms or 1.33 ohms.  The T15002 is a two-channel amp, so with three subs you will be bridging.  1.33 is far too low of a load to bridge, so you would have to use 12 ohms load per set of subs.  With an output of 1000 watts into a bridged 4 ohm load, you can calculate that the amp would make 375 watts into a bridged 12 ohm load.  375 * 3 amplifiers = 1125 watts.

That's not very much more power than you have right now using just one amp with 1000 watts.  You may not even be able to distinguish a quality difference and you certainly won't notice much db increase if you do at all, and to show for it would be the cost of two more of these amplifiers.

See what I meant when I said I don't see the possibility of adding more of this particular amplifier for more output?  If you want closer to 200 watts per sub with this set of nine, you'll have to use just one two-channel amplifier that makes more power than the T15002 does.  Or the best bet...if it seems loud enough like it is, leave it with just the one amp.  Although the subs can take 200 watts, they are perfectly comfortable receiving 110.

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

Thanks Stevdart. That's something I had no idea about. You're totally right. People were saying that if I wanted to get into SPL comps that I would need more then the one amplifier but I thought it was just a reason to spend more money. Maybe more amplifiers but why so big and so costly. Those amplifiers run $1,499.99 each.....ouch! I'm new to car audio so the input is greatly appreciated. I think if I want more db then I should be looking at some more powerful subs but then I am looking at more cost again and there is no way I am getting that box out of the van without a chain saw or something (took a winch, sledge hammer, and a 4 people to put it in). A very big Thank You for the help and advice.

If you knew then what you know now,

• You wouldn't have designed that box for nine subs, or
• You wouldn't have chosen SVC4 ohm subs, or
• You wouldn't have chosen a two-channel amplifier

A change you might consider for the future would be to trade out all nine of those subs to 8 ohm ( or DVC 4 ohm) versions.  This would net a 2 ohm load on the amp, and since it's capable of a 2 ohm bridged load, it would ouput an additional 500 watts.  Your wiring diagram would stay the same with the only exception that each sub's coils would be wired in series, which is just a connecting wire from coil 1 - to coil 2 +.  No changes to wiring within the structure itself.  You might as well use the amp for all it's worth (never thought I'd say that but we are talking about 9 subs here) for that kind of expense.  1500 / 9 = 166 watts per sub, which isn't too bad (of course, we don't know what the DVC 4 sub is yet).  I don't know how the amp performs as I'm not familiar with it, and loading it at 2 ohms would put it to the test, but that's what it says it will do.

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

That's where things atart to get confusing for me. I am very new to this and this is my first custom install over a 2 month period so I have overloaded my brain with so much stuff that I am starting to get to the confused stage.

A friend of mine is the one doing the tuning and power setup for me so when it comes to setting the amp, I don't even touch it. I don't really know the advantages or disadvantages between SVC and DVC. I don't know the power distribution from the amplifier to the subs. There is alot for me to learn and what I have learned has been mostly from here. The advice you guys have been giving me is exactly what I need and have been looking for but my brain is so overloaded with this system and work that I get lost.

It is probably possible that I would have to build a different box to house the dual voice coil subs, would I not? And this box right now is not ported. Each chamber is exactly 14" x 14" x 7.5" = 0.85 ft3. I guess it all depends on the look I am going for as well as the type of bass. I know you get a higher SPL with a ported box but for that instant hard hitting bass I think the sealed box is better is it not? People say about the whole air flow things and how that hits you more but does it really give you that much bass when that air flow is not coming directly from the sub? Maybe I am just questioning myself too much but these are definately factors I will need to consider when it somes right down to it.

As for building the box. Remember to measure the height on the sides of the vehicle too (not just the middle). I got laughed at for that one. At least I know I got a roll cage if I ever get into an accident cause it's not moving anywhere.

You shouldn't have to do any box rebuilding at any time.  .85 is a good workable sealed size for a large number of different subs.  What you should do is just enjoy your system and stay with this forum to learn.  Don't get all caught up in trying to compete yet, but show off your hard work.  Everybody's got advice for you, remember that, and most of it will be either unnecessary or flat out wrong.  Let it flow in and out, and take your time grasping the major concepts of audio and 12 volt electronics.  It takes everybody a lot longer than two months.

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.