2 ohm stable? - AVS Forum
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post #1 of 25 Old 03-03-2007, 10:02 AM - Thread Starter
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Anyone know of a good 2 ohm stable plate amp? Or, is it bad to wire to just one voice coil of a dual 4 ohm voice coil speaker? Thanks.
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post #2 of 25 Old 03-03-2007, 11:50 AM
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Use two plate amps, one on each coil. Or get a BIG plate amp like the Nady or Behringer pro amps. My "plate" amp is the Nady XA900 and it is totally stable into two ohms in parallel mono mode.

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post #3 of 25 Old 03-03-2007, 05:31 PM - Thread Starter
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Thanks , I will check those out.

Can anyone give some insight on the performance I should expect wiring an amp to just one voice coil of a dual 4 ohm voice coil speaker?
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post #4 of 25 Old 03-03-2007, 06:02 PM
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I believe that you will only be using half of the drivers motor performance potential by only using one voice coil. I dont think its a good idea.
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post #5 of 25 Old 03-03-2007, 06:08 PM
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What sort of alignment are you going to use? Small sealed, small ported, large low tuned, IB? It may make a difference. If the cone is mostly unloaded by a huge box or IB then one coil may be all you need. If you have a small sealed box you may not get enough excursion using one coil.

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post #6 of 25 Old 03-03-2007, 06:46 PM - Thread Starter
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It is a 1.25 cf box with 1 4" port. The speaker is 10". I am mostly concerned that hooking up one coil may damage the speaker. If this is not the case I will just hook it up and hear how it sounds.
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post #7 of 25 Old 03-03-2007, 06:55 PM
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You will not damage the speaker. Just have very low output.

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post #8 of 25 Old 03-03-2007, 09:08 PM
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Use just one coil if you wish. It won't hurt the speaker. Output will be reduced, not to 50% but more like to about 75-80% of the speakers rating. Here's a white paper by Dan Wiggins on the subject of dual voice coil drivers, for more info: http://www.adireaudio.com/Files/Tech...oilDrivers.pdf
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post #9 of 25 Old 03-04-2007, 08:38 AM - Thread Starter
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Great paper by Dan, thanks. I will try hooking up one voice coil and then wired in series.
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post #10 of 25 Old 03-04-2007, 09:16 AM
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At the moment, I don't know of any plate amps that are 2 ohm stable. It is a shame that there are not more offerings in the plate amp dept. The most powerful seems to be the new Elemental Designs 1300w plate amp. It is very affordable, but has not been tested for real world output.

The Nady and Behringer amps referenced above are not plate amps. So, I am not sure why/how they got mentioned.

It sure would be nice if there were a, say 2000+ watt plate amp in 2/4 ohm stable form. It would be hugely popular for the DIY crowd.

Some amps are built quite a bit more solidly and have better protection circuits. There may be amps that might tolerate a 2 ohm load and not complain or shutdown. The trouble is you have to test this theory at your own risk. It will certainly void the warranty and may even burn up the amp in the process...

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post #11 of 25 Old 03-04-2007, 10:26 AM
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My Nady is a plate amp. About three inches thick nineteen inches wide and sixteen inches deep. Would easily screw onto the back of a box.

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post #12 of 25 Old 03-04-2007, 11:19 AM - Thread Starter
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I agree Joe. I have a DVC 4ohm sub. I can run 1 coil at 4ohms or wire both coils in series at 8ohms. Neither option is ideal. A good 2ohm stable 1000w plate amp that fits my existing box would be great. Am I asking too much?

If my 2 wiring options do not produce satisfactory results I think I will build a new box big enough to house 2 plate amps, one for each coil. Thanks HT Nut, that was something I had not considered. If nothing else, it will be a fun experiment.
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post #13 of 25 Old 03-04-2007, 02:46 PM
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Quote:
Originally Posted by HT Nut View Post

My Nady is a plate amp. About three inches thick nineteen inches wide and sixteen inches deep. Would easily screw onto the back of a box.

Your Nady is not a plate amp. A plate amp is an amp on a plate where the plate is made to flush mount into the back of an enclosure. The Nady is a rack mountable pro style amp.

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post #14 of 25 Old 03-04-2007, 02:47 PM
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Quote:
Originally Posted by 051473 View Post

I agree Joe. I have a DVC 4ohm sub. I can run 1 coil at 4ohms or wire both coils in series at 8ohms. Neither option is ideal. A good 2ohm stable 1000w plate amp that fits my existing box would be great. Am I asking too much?

If my 2 wiring options do not produce satisfactory results I think I will build a new box big enough to house 2 plate amps, one for each coil. Thanks HT Nut, that was something I had not considered. If nothing else, it will be a fun experiment.

I have never experimented with running only one VC. I am told it is a viable option as the article referenced above states. I am going to contact Kyle at TC Sounds and get their opinion as well.

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post #15 of 25 Old 03-04-2007, 03:41 PM - Thread Starter
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I would love to hear his opinion. I have a Dayton amp coming in the mail. I will report back when I get it hooked up.

I looked up HT Nuts Nady amp. From the pics it does not appear to be a plate amp but rather a rack mount. But, I suppose just about anything could be attached to a box.
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post #16 of 25 Old 03-04-2007, 07:19 PM
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Quote:
Originally Posted by 051473 View Post

I would love to hear his opinion. I have a Dayton amp coming in the mail. I will report back when I get it hooked up.

I looked up HT Nuts Nady amp. From the pics it does not appear to be a plate amp but rather a rack mount. But, I suppose just about anything could be attached to a box.

Ya, definitely no plate amp there. I will let you know what they say, should be interesting reading regardless.

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post #17 of 25 Old 03-04-2007, 08:06 PM
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So now we are going to get picky about the thickness of the plate. I just offered that it could be mounted with no more difficulty than any of the plate amps. In fact, probably with less difficulty. If the fans were reversed in flow the controls could be on top and make a nice amp for any reasonable sized box. Ya gotta be an improviser if you are going to DIY.

And here is a pic of the amp with low noise fans installed.

http://www.digphoto.net/HT/nadyfans.jpg

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post #18 of 25 Old 03-04-2007, 09:32 PM - Thread Starter
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Another question: My DVC speaker is rated at 250w rms. Is this 250w per voice coil? If I go with Jerry's suggestion I will be running 2 250w plate amps at 4ohms, one for each voice coil. I know some headroom is good but is that too much power. (Is there such a thing as too much power with a sub?)
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post #19 of 25 Old 03-04-2007, 10:21 PM
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There is never any thing as too much power for speakers, as long as you are aware of the limits of the speaker. Far more speakers are damaged by amps clipping than by a brief overpowering. If you get two amps and have more power than is required, just keep the level controls turned down a bit.

Not sure how your speakers are rated, per coil or total for both coils. Do you have manufacturer manuals or datasheets?

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post #20 of 25 Old 03-05-2007, 06:04 AM
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Quote:
Originally Posted by 051473 View Post

Another question: My DVC speaker is rated at 250w rms. Is this 250w per voice coil? If I go with Jerry's suggestion I will be running 2 250w plate amps at 4ohms, one for each voice coil. I know some headroom is good but is that too much power. (Is there such a thing as too much power with a sub?)

If the speaker is rated at 250w RMS it is for both VCs combined.

You can run your VCs in either serial or parallel. I would avoid running two amps for the same sub. Yes, it will work fine but it is just a waste of space. I would just get a stronger amp and run the VC in series giving the amp an 8 ohm load, which any amp will love. It is easier on the amp to go up in ohms but not down. When you go up you lose power output but the amp does not work as hard.
For instance if your amp is rated at 500 watts at 4 Ohms, with an 8 Ohm load it may only out 250 or thereabouts. Just plan accordigly and you will have more flexibility with a more powerful amp.


You will just want to get something that is around 500 watts or so. Like HT Nut said, don't be afraid of too much power. You can always turn the gain down a little too. In addition, often the amps do not put out quite what they are rated at in "real world" conditions.

Also, there is very little price difference in 250 vs. 500 watt amps and you can re-use the bigger amp if you have a bigger and better project on down the line.

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post #21 of 25 Old 03-05-2007, 06:36 AM
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Quote:
Originally Posted by HT Nut View Post

So now we are going to get picky about the thickness of the plate. I just offered that it could be mounted with no more difficulty than any of the plate amps. In fact, probably with less difficulty. If the fans were reversed in flow the controls could be on top and make a nice amp for any reasonable sized box. Ya gotta be an improviser if you are going to DIY.

And here is a pic of the amp with low noise fans installed.

http://www.digphoto.net/HT/nadyfans.jpg

Sorry to be picky about it, but there is quite a difference; no fans, built in crossovers, made to seal in the enclosure, about 1/5 the weight, much less current draw, etc. etc.

Agreed on the improvising, but in this case I think a real plate amp would work a little better especially when not much power is required.

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post #22 of 25 Old 03-06-2007, 10:15 AM
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Quote:
Originally Posted by 051473 View Post

I would love to hear his opinion. I have a Dayton amp coming in the mail. I will report back when I get it hooked up.

Check your PM. TC Sounds responded to our question.

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post #23 of 25 Old 03-06-2007, 10:25 AM
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Quote:
Originally Posted by 051473 View Post

It is a 1.25 cf box with 1 4" port.

How long is the port? What's the Fb?

-Robert
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post #24 of 25 Old 03-06-2007, 11:07 PM - Thread Starter
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Thanks for the help and advice everyone. I have decided to start from scratch and build a new sub instead of trying to make the parts I have work. I have never done this before so I am looking forward to learning something new and hopefully the result will sound great. Thanks again.
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post #25 of 25 Old 03-07-2007, 05:41 AM
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Good Luck! And remember to have fun during the process.

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