2 amps to 1 sub?

kolk1] wrote:

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y amps are rated at 1000 RMS at 1 ohm.

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So... what's your amp rated at 4 Ohms?  I'm going to guess that your VC do not equal 1 ohm each, so putting 1 amp into 1 VC isn't going to give you the power you're looking for.

Hardwarz

hardwarz wrote:

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kolk1] wrote:

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y amps are rated at 1000 RMS at 1 ohm.

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So... what's your amp rated at 4 Ohms?  I'm going to guess that your VC do not equal 1 ohm each, so putting 1 amp into 1 VC isn't going to give you the power you're looking for.

Hardwarz

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kolk1] wrote:

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es, its a DVC. But it would damage the sub if one coil was getting slightly more or less power than the other voice coil. .

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This is a false statement.  The only damage would be if the amplifier is producing more power than the voice coil (or the mechanical suspension) can handle.

punkguyta wrote:

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hardwarz wrote:

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kolk1] wrote:

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y amps are rated at 1000 RMS at 1 ohm.

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So... what's your amp rated at 4 Ohms?  I'm going to guess that your VC do not equal 1 ohm each, so putting 1 amp into 1 VC isn't going to give you the power you're looking for.

Hardwarz

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Actually if the amp is stable at 1 Ohm then 1000 watts to a 2000 watt subwoofer will probably be plenty loud unless you're trying to do some spl battleing.

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I know I've been out of this for a while, but it use to be that bridging and  dropping the load to the amp increased the power of the amp.  If that's true and you give the amp 4 ohms bridged, it won't produce the 1000W  that it's suppose to.  correct?

DYon, you are wrong, in stating that if both coils receive different power, that no damage will occor. You are correct in the fact that it all must be in phase. Here is a lengthy, & correct way to Gain Match (Voltage match is the wrong term) two amplifiers.

You will need a sub that can handle the amp wide open. A Test CD with multiple frequencies, & a DMM on the AC voltage setting.

1. Hook up 1 amp, gain at full, x-oxer at full, bass boost at full. Hook the sub up so it reads closest to the ohm load that you will be using in the end. Play test tones starting at 25Hz  up to 120Hz(assuming there is no sub sonic filter on the amp), rolling on the volumne knob on the deck, untill the amp is at full saturation (where the volt meter no longer increases in #'s). Do this to find the frequency of max output from the amp. Now do the same with amp #2. Make shure your charging system can keep the voltage to the amp constant, to ensure accurate results.

2. Hook up the WEAKER of the 2 amps, & set the gain, X-over point, & bass boost as you normally would. Hook up the STRONGER of the 2 amps (this time 1 amp to each voice coil), & at low volumne, set the output at all the frequencies the same (or within .3 of a volt). Start with the settings on the stronger amp all the way down, set gain approx, tune in bass boost frex. & level, & x-over point...then fine tune it in. This will ensure that, gain, bass boost frequency, & x-over point are all set the same (no matter what the knobs on the amps say).

3. Turn the volumne up, to max output of the weaker amp, & check the output of the stonger amp, to make shure it is still within .3 of a volt.

I learned this from a post Jeff Sanford did on the USACi forums a long time ago....in 04 I think, & have used it multiple times, & it works perfectly......it does seem that any more than a .3 variance in the out put, gives that burning VC smell....so make shure the DMM you use is accurate.

Just a side note, the ZAPCO DC amps WILL NOT work well this way, as the adjustment increments are too large, & (with the 1100.1) max output voltages can't be matced, even with adjsting the rail voltage, not just the gain structure) 

IF power is different to each voice coil, one with more power will try to move farter than the other, & WILL destroy the sub, as it will "push" the other VC, & generate exessive heat. You can easily prove this by hooking up matching subs, in the same sealed box, hook a 1000W amp to one sub, & a 500W amp to the other, & count how many seconds it takes for you to smell VC burning. do the same with 2-1000W amps, & count the time. The sub getting the LESSER power will get destoryed first, because it is being FORCED to move. Same goes for our DVC with different power to each VC, the one with lesser power with be forced to move.

ibasspro wrote:

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DYon, you are wrong, in stating that if both coils receive different power, that no damage will occor.

IF power is different to each voice coil, one with more power will try to move farter than the other, & WILL destroy the sub, as it will "push" the other VC, & generate exessive heat. You can easily prove this by hooking up matching subs, in the same sealed box, hook a 1000W amp to one sub, & a 500W amp to the other, & count how many seconds it takes for you to smell VC burning. do the same with 2-1000W amps, & count the time. The sub getting the LESSER power will get destoryed first, because it is being FORCED to move. Same goes for our DVC with different power to each VC, the one with lesser power with be forced to move.

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That is utter BS.

haemphyst wrote:

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basspro, I know you didn't just tell a mod that he was wrong, PARTICULARLY when you are the one who is wrong...

Read this... ALL OF IT!!! When you've read it ALL, (and I will test you...) THEN come back and apologize.

You cannot cause any damage to a subwoofer by connecting one voice coil OR connecting two amplifiers to it. Run one completely out of phase, for all the woofer is concerned, it WLL NOT DAMAGE the woofer, as long as power and mechanical limits are observed. Period, and end of story.

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I skimmed all 14 pages (sorry, but most of it was just banterings, or simple questions that have been asked & answered many time), & did not see one post about running 2 different amps to 1 speaker...although page 11 had some very good info (in wich I read in full). I AM correct on how to match 2 amps to one sub, in wich that thread has no mention of what so ever. So go ahead, test away, or we can stop this wizing match, & ensure the proper way of matching 2 amps to one sub is posted. It is not how much you or I know, it is getting that knowledge to those that need it.

Perhaps it would be better for you to just call me, as somehow I must be reading things incorrectly. My Phone # is (408) 406-8773 Tony Sorritelli, Just because he is a moderator, does not mean he is infallible....& I was not trying to be a jerk about it, & if it came off that way I apologise.

(I intend no animosity what so ever...so please do not read it that way)

IF you beleive it is BS, please do the test I posted. You will find out that it is true & correct. Perhaps not in theory, but in reality. I can save you the time, as I have done it, & the one with LESS power got destroyed. I did not type that because it is somehting I am guessing. I have done it, that is what happened, period.

Flame away if y'all want, I gotta get back to work. I stand by the post, as it is a very solid way to match 2 amps to one DVC sub.

ibasspro wrote:

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IF you beleive it is BS, please do the test I posted. You will find out that it is true & correct. Perhaps not in theory, but in reality. I can save you the time, as I have done it, & the one with LESS power got destroyed. I did not type that because it is somehting I am guessing. I have done it, that is what happened, period.

Flame away if y'all want, I gotta get back to work. I stand by the post, as it is a very solid way to match 2 amps to one DVC sub.

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I've done it many times with no issue UNLESS (as I said in the initial post) the voice coil is overpowered.  But there is no (repeat NONE) problem using different power levels from different amps on a DVC speaker (indeed, even completely different signals can be used with no damage what so ever.)

I agree, there is nothing wrong with your instructions on how to match the output levels of two amps.  That is not the issue.  The issue is that you do NOT have to do that if your intention is simply to avoid speaker damage.  The only thing that will damage a loudspeaker voice coil is over power.  Period.

kolk1] wrote:

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Ok, wow. Left last night with one response, came back to 3 pages lol.

Ill answer the main question, I was asked what my amps are rated at, at 4 ohms. The sub Im looking at is available in a dual 2. So my amps would be at 2 ohms each, roughly 800RMS each. These amps are supposedly underrated as well, but who knows for sure. But 1600 RMS so a single 12, should be good enough.

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ibasspro wrote:

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used to be loud, used to be fast...now I am married LOL

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punkguyta wrote:

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kolk1] wrote:

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Ok, wow. Left last night with one response, came back to 3 pages lol.

Ill answer the main question, I was asked what my amps are rated at, at 4 ohms. The sub Im looking at is available in a dual 2. So my amps would be at 2 ohms each, roughly 800RMS each. These amps are supposedly underrated as well, but who knows for sure. But 1600 RMS so a single 12, should be good enough.

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For a 1600 watt sub TWO amps would be more than enough but being that each VC is half the rating that's 800 watts each, however you'd be safer off running the sub on one single amp even a 800 watt amp by itself will be enough power. Right now I'm running a 1200 watt sub off a 300 watt (max) panel amp and it's loud enough.

Rule of thumb, the amplifier doesn't care how many watts the speaker is as that doesn't matter, what matters is that the ohms match the amp. So if your sub is a dual 2 ohm, parallel wiring it would present a 1 Ohm load (Don't do that bad idea) so wire it in series to present a 4 Ohm load and you should be laughing.

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What sub do you have that is rated at 2000 watts?

Also, the difference between 1000 watts and 2000 watts in the same speaker is only +3db.  Hardly enough to justify the extra expense unless you are competing.

It will NOT hurt, period. You've got all the documentation to prove it -courtesy of haemphyst.

I'm currently powering a single 4ohm DVC sub with 2 2channel amps. Each amp is rated for 250Wrms x 1 @ 4ohms. The sub is rated for 450Wrms (both coils). So, I'm slightly overpowering the sub, by 50watts.

Bottom line is, go for it unless you don't want to spend the money.

Keep in mind of the amps RMS power rating @ 2ohms, as each coil has an impedance of 2ohms.

You'll probably be better off (for the money) to get 2 mono amps that put out full power into 2ohms, not 1. But, for efficiency and sub control, you're well off as it is. Have Fun!

kolk1] wrote:

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The sub can take 2000 RMS. If I run the sub in parallel, I wont be able to run 2 amps, so Id only be able to give it 1100 RMS. By running one amp per VC, ill be able to give it a total of 1600 RMS. I already have these amps. And down the road I will probably buy one amp that does 2000RMS at 1ohm, but for now, Id just like to get the box built, and buy the sub, and be able to push it as hard as possible, since it might be summer time before I decide to dive into buying a new amp.

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aznboi3644 wrote:

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it still wouldn't matter if you had and amp on each coil as long as the signals were the same phase.

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ibasspro wrote:

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IF power is different to each voice coil, one with more power will try to move farter than the other, & WILL destroy the sub, as it will "push" the other VC, & generate exessive heat.You can easily prove this by hooking up matching subs, in the same sealed box, hook a 1000W amp to one sub, & a 500W amp to the other, & count how many seconds it takes for you to smell VC burning. do the same with 2-1000W amps, & count the time. The sub getting the LESSER power will get destoryed first, because it is being FORCED to move. Same goes for our DVC with different power to each VC, the one with lesser power with be forced to move.

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punkguyta wrote:

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aznboi3644 wrote:

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it still wouldn't matter if you had and amp on each coil as long as the signals were the same phase.

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If it were perfectly set up, yes it wouldn't matter. However you need balanced outputs, exactly the same amps (model wise) and would defiantly have to play around with a volt meter and a sound generator. But this guy has two different amps, which means they are different amplifier chipsets basically and have different outputs, different in line effects too probably and it would be hard to get as clean as a sound out of the two as you could get having the coils wired together. Not to mention he needs a way of having a balanced input.

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Matching the amplifier outputs is necessary to attain maximum performance from a single speaker/dual amp setup, but again, it is not necessary if all you're trying to do is not damage the subwoofer.  I will say it again: you can send two completely different signals at completely different power levels from completely different amplifiers to the two coils of a DVC woofer, and as long as you do not exceed the power handling capability of the coils, the speaker will be fine.  You may not get the output you expect if the signals cancel each other by being out of phase, but the speaker will not care at all.

DYohn] wrote:

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punkguyta wrote:

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aznboi3644 wrote:

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it still wouldn't matter if you had and amp on each coil as long as the signals were the same phase.

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If it were perfectly set up, yes it wouldn't matter. However you need balanced outputs, exactly the same amps (model wise) and would defiantly have to play around with a volt meter and a sound generator. But this guy has two different amps, which means they are different amplifier chipsets basically and have different outputs, different in line effects too probably and it would be hard to get as clean as a sound out of the two as you could get having the coils wired together. Not to mention he needs a way of having a balanced input.

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Matching the amplifier outputs is necessary to attain maximum performance from a single speaker/dual amp setup, but again, it is not necessary if all you're trying to do is not damage the subwoofer.  I will say it again: you can send two completely different signals at completely different power levels from completely different amplifiers to the two coils of a DVC woofer, and as long as you do not exceed the power handling capability of the coils, the speaker will be fine.  You may not get the output you expect if the signals cancel each other by being out of phase, but the speaker will not care at all.

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punkguyta wrote:

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But would you play your prized subwoofer at high volumes with different signals going to each vc for a couple hours? No cuz you know it would bust apart.

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You are simply wrong.  I will say it again: as long as the power handling capability is not exceeded NOTHING bad will happen to the woofer.  Period.

punkguyta wrote:

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But would you play your prized subwoofer at high volumes with different signals going to each vc for a couple hours? No cuz you know it would bust apart.

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punkguyta wrote:

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But would you play your prized subwoofer at high volumes with different signals going to each vc for a couple hours? No cuz you know it would bust apart.

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It's obvious that you didn't read the link Heamphyst gave earlier in the thread.  If you did then you would know that out of phase signals sent to each coil wouldn't cause physical damage (as long as power limits aren't exceeded), but would just cancel out the magnetic field produced by the coil resulting in no (or greatly reduced) cone movement.  Here's the link again, and I suggest you read it this time: https://www.adireaudio.com/Files/DualVoiceCoilDrivers.pdf

DYohn] wrote:

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punkguyta wrote:

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But would you play your prized subwoofer at high volumes with different signals going to each vc for a couple hours? No cuz you know it would bust apart.

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You are simply wrong.  I will say it again: as long as the power handling capability is not exceeded NOTHING bad will happen to the woofer.  Period.

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Steven Kephart wrote:

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punkguyta wrote:

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But would you play your prized subwoofer at high volumes with different signals going to each vc for a couple hours? No cuz you know it would bust apart.

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It's obvious that you didn't read the link Heamphyst gave earlier in the thread.  If you did then you would know that out of phase signals sent to each coil wouldn't cause physical damage (as long as power limits aren't exceeded), but would just cancel out the magnetic field produced by the coil resulting in no (or greatly reduced) cone movement.  Here's the link again, and I suggest you read it this time: https://www.adireaudio.com/Files/DualVoiceCoilDrivers.pdf

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aznboi3644 wrote:

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how would it bust apart if the cumulative power to the sub did not exceed the thermal limits or the mechanical limits.

I don't know why you keep fighting an already lost battle

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punkguyta wrote:

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DYohn] wrote:

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You are simply wrong.  I will say it again: as long as the power handling capability is not exceeded NOTHING bad will happen to the woofer.  Period.

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Playing your sub with each vc wanting to go in a diff direction is "Eventually" gonna break something and possibly cause spyder damage.

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Nope.  You simply do not understand how loudspeakers work my friend.

DYohn] wrote:

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punkguyta wrote:

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DYohn] wrote:

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You are simply wrong.  I will say it again: as long as the power handling capability is not exceeded NOTHING bad will happen to the woofer.  Period.

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Playing your sub with each vc wanting to go in a diff direction is "Eventually" gonna break something and possibly cause spyder damage.

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Nope.  You simply do not understand how loudspeakers work my friend.

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OR you just don't have respect for your equipment.
___________________________________________
Chrysler LHS w/ infinity 11 speaker factory system, 1200 watt sub on the way.

THAT is just simply too funny.

(I think this subject's dead, ed.)

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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.

Yep that's me, absolutely no respect for equipment.  Duh, how'd I ever make it in this industry all these years?   

punkguyta, I am trying to help you understand the truth but obviously that is a losing proposition.  After you get a little experience and maybe take some classes come on back and we'll chat.