# two amps one sub, lets debunk this myth!!



## pitchblackcls6

Some words from Adire Audio, i def agree.

http://www.adireaudio.com/Files/DualVoiceCoilDrivers.pdf


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## jking29

*Re: two amps one sub, lets bebunk this myth!!*

Nothing on that page talks about running two separate amps to one sub.


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## brownmoses

*Re: two amps one sub, lets bebunk this myth!!*



jking29 said:


> Nothing on that page talks about running two separate amps to one sub.



LMAO. none at all. 

Here's Two girls one cup, err, i mean two amps, one sub in a nutshell. They must be strapped if possible ending up as one amp anyway, or you feed two amps to two coils on the same sub (one amp per coil).
the amps must be the same and it very beneficial to gain match the amps to be sure each coil is getting the same power and the same mono signal as to not try to feed a stereo signal to one speaker. Thats it....no myth.


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## fish

*Re: two amps one sub, lets bebunk this myth!!*

That's debunk by the way.


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## pitchblackcls6

*Re: two amps one sub, lets bebunk this myth!!*

@ jking29
my bad, should have been more specific, two separate signals to one sub, which could be substituted as also one signal from one amp and one signal from another amp. meaning, as it said in that pdf file:

There's one thing that often comes up about wiring DVC subs, and that is the mistaken conclusion that
running different signals to each voice coil will "ruin" the driver. Let's recall how a dual voice coil driver is
built. Basically, a dual voice coil driver consists of two motors (the voice coils) co-axially mounted (that is,
wound together on the former) to a single diaphragm. The net force on the diaphragm is the sum of the
inputs of the two motors.

So, when we run two different signals to the voice coils, what we find is that the magnetic fields of the two
combine to generate a net TOTAL field that interacts with the static field of the magnets. The two voice
coils NEVER fight each other in a physical way; it's all in the magnetic field.

@brownmoses
as you said, one amp per coil, and matched. I've spent the past year on these forums and the net in general, and its pretty widely accepted that if you feed anything other than a mono signal to amy speaker it will magically eat its self up. all im trying to do is make people understand why it wont. people come to these forums for advice and direction, and it seems most times a good post goes bad because people run off on tangents or start to bicker and take shots at eachother.
just trying to get some info out there to the "less informed"


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## Oliver

*Re: two amps one sub, lets bebunk this myth!!*



pitchblackcls6 said:


> So, when we run two different signals to the voice coils, what we find is that the magnetic fields of the two
> combine to generate a net TOTAL field that interacts with the static field of the magnets. The two voice
> coils NEVER fight each other in a physical way; it's all in the magnetic field.


*Can I run 80 Hz to 120 Hz to one voice coil from one amp and run 75Hz and down form another amp to the second voice coil ?*


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## PaulD

*Re: two amps one sub, lets bebunk this myth!!*

sure you CAN ... may not do much for you


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## Oliver

*Re: two amps one sub, lets bebunk this myth!!*



pitchblackcls6 said:


> @ jking29
> my bad, should have been more specific, two separate signals to one sub, which could be substituted as also one signal from one amp and one signal from another amp.
> 
> There's one thing that often comes up about wiring DVC subs, and that is the mistaken conclusion that
> running different signals to each voice coil will "ruin" the driver. Let's recall how a dual voice coil driver is
> built. Basically, a dual voice coil driver consists of two motors (the voice coils) *co-axially mounted*





PaulD said:


> sure you CAN ... may not do much for you


Thanks PaulD,

Yeah my coaxials play from about 120 Hz and up 5.25's , just wanted to make sure my sub could due the co-axial thing too , for the remaining frequencies


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## [email protected]

*Re: two amps one sub, lets bebunk this myth!!*



Oliver said:


> *Can I run 80 Hz to 120 Hz to one voice coil from one amp and run 75Hz and down form another amp to the second voice coil ?*


I would say you can do anything you want, because as your mom used to say, "your special", might be short bus special, but none the less you are special!!!


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## Oliver

*Re: two amps one sub, lets bebunk this myth!!*

If *pitchblackcls6* says it's OK ... then i know I am G-O-L-D-E-N !


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## cobra93

*Re: two amps one sub, lets bebunk this myth!!*

As I understand it, the reason DVC subs came about is because of the lack of powerful amps available at the time. So you would hook both channels of one amp to it, not necessarily a mono signal. The coils may not be working together optimally, but it shouldn't harm the woofer.
In other words I disagree that the amps "must" be gain matched perfectly or a mono signal "has" to be used or the amps must be strapped.
If you hook two identical amps to a dvc sub and the gains aren't "matched" you would not damage the sub, both coils would still contribute to the movement of the cone, just not equally.

Edit: I reread post #5 and agree with pitchblackcls6, the woofer will not be harmed.


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## Oliver

*Re: two amps one sub, lets bebunk this myth!!*

JL Audio - Car Audio Systems


What is a dual voice coil speaker? 
- 
*JL Audio *Car Audio Systems

Where a dual voice coil subwoofer has an advantage is in giving the user greater wiring flexibility while avoiding speaker-to-speaker series connections


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## Oliver

*Re: two amps one sub, lets bebunk this myth!!*



> What happens when you run different signals into each voice coil of a dual voice coil speaker?
> Essentially, if there is any difference between the signals driving each coil at any given point in time at a given frequency, the voice coils will either fight each other or help each other, depending on the phase relationship of the two signals at that frequency. This is not the same thing as bridging an amplifier and can create undesirable non-linearities and distortion because* different input signals at each voice coil create shifts in the speakers electrical parameters.*
> 
> For this reason, it is advisable to mono-bridge the amplifier whenever possible and connect the voice coils of the dual voice coil speaker together in parallel or series. If a dual voice coil subwoofer must be wired to two independent channels, the inputs to both channels should ideally be the same (summed mono) and every effort should be made to match the gains of both channels as closely as possible.


Hmmm


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## cobra93

*Re: two amps one sub, lets bebunk this myth!!*



Oliver said:


> Hmmm


I don't see anything that states damage will occur, only that it's not optimal.
My thoughts on what you posted.


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## Oliver

*Re: two amps one sub, lets bebunk this myth!!*



cobra93 said:


> I don't see anything that states damage will occur, only that it's not optimal.
> My thoughts on what you posted.


But . . . do U want to find out , that towing a boat with a 4 cylinder car can be done - *once or twice before you need a new transmission ?*

I mean if U do . then *GO FOR IT !*


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## pitchblackcls6

*Re: two amps one sub, lets bebunk this myth!!*

so it seems that few people actually read that article, some looked at it but didnt read it. 
has anyone actually tried this? im curious to see what the difference would be. how it would actually degrade the life of the speaker. 

@oliver- yes you are golden because i said so, thanks for the shout out!


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## cobra93

*Re: two amps one sub, lets bebunk this myth!!*



Oliver said:


> But . . . do U want to find out , that towing a boat with a 4 cylinder car can be done - *once or twice before you need a new transmission ?*
> 
> I mean if U do . then *GO FOR IT !*


It's interesting to me that you used an analogy that's directly related to a components ability to dissipate heat. The engine that's in front of the transmission is only one variable, a small one at that, that will dictate the life span of the transmission. In fact an eight cylinder with more available torque and a heavy foot will overheat the transmission faster than the four cylinder would. I could go on, but that's not what this topic is about.

I've learned not to concede to other peoples "opinions" if I have a decent grasp of the subject, it may cost me some of the time, but in most cases it turns out ok.

Unless you're approaching the thermal limits of the coil and it's ability to cool itself, no damage will occur. Either the two coils will contribute to motion or one will hinder the other.


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## Oliver

*Re: two amps one sub, lets bebunk this myth!!*

cobra93,

Is it worth the price of an amplifier and subwoofer to try it ? 

I've seen guys try to use one coil on a DVC sub [ 3 dB less output when you use half the available motor, wrong box as parameters change ], can it be done ... sure !

would you want too ?


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## cobra93

*Re: two amps one sub, lets bebunk this myth!!*



pitchblackcls6 said:


> so it seems that few people actually read that article, some looked at it but didnt read it.
> has anyone actually tried this? im curious to see what the difference would be. how it would actually degrade the life of the speaker.
> 
> @oliver- yes you are golden because i said so, thanks for the shout out!


Maybe I've missed something. 
In your first couple posts you stated that you agreed with the link you posted.
It sound as though you're know unsure on your stance.

I assume you're referring to subs.
Is this really relevant with the cheap class D power available today?

From your last post: "how would this degrade the life of the speaker".
Unless the varnish/glue holding the coil windings fail and cause a short, what would cause degradation of the speaker?

I think the more important question(s) to ask here is(are): What (or how much more) distortion would be the result of sending stereo/different signals to the coils on a DVC speaker, would it be audible to most people?

I'm trying to understand your thought process here.


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## cobra93

*Re: two amps one sub, lets bebunk this myth!!*



Oliver said:


> cobra93,
> 
> Is it worth the price of an amplifier and subwoofer to try it ?
> 
> I've seen guys try to use one coil on a DVC sub [ 3 dB less output when you use half the available motor, wrong box as parameters change ], can it be done ... sure !
> 
> would you want too ?


How would this cause damage to the amplifier?
Using one coil most certainly changes the T/S parameters, but that's a different subject all together.

I've never seen a sub that only works under one set of enclosure parameters. Have you?
Couple that with the fact that everybody has their own preference as to what sounds good to them and the possible box parameters/wiring configurations are endless.
Would I use only one coil on a DVC sub, if it models/sounds the way I want it to, yes.

Did you read the link in post #1 in regards to using a variable potentiometer on one coil to change the Q of a woofer?
Why would this be suggested/implemented if damage to the woofer would result? This is from a manufacturer of subwoofers and some very good sounding subs, at least that's what I've read.

I don't propose this to be fact, just what makes sense to me based on my knowledge and understanding.


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## Oliver

*Re: two amps one sub, lets bebunk this myth!!*



cobra93 said:


> I think the more important question(s) to ask here is(are): What (or how much more) distortion would be the result of sending stereo/different signals to the coils on a DVC speaker,* would it be audible to most people?*
> 
> I'm trying to understand your thought process here.


At 80 Hz and down a large amount of people cannot hear 15% distortion - hence the "My sub took a **** and I was playing it very low"-POSTS

amp is sent into clipping 24/7 because they bought a really cheap ass amp and clipped it til hell wouldn't have it.

*End result ?*


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## Muggy

*Re: two amps one sub, lets bebunk this myth!!*

Yes it can be done! I've done this many times in Db Drag. Not recommended for daily driver. You have to match the voltage output of the amps. You can actually run 4 amps on one sub. 2 amps strapped on one voice coil and 2 amps strapped on the other. But I can't stress it enough the voltage output HAS to be matched! If one voice coil will end up frying and sounding like a spring or seizing up!!


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## thomasluke

*Re: two amps one sub, lets bebunk this myth!!*



Muggy said:


> Yes it can be done! I've done this many times in Db Drag. Not recommended for daily driver. You have to match the voltage output of the amps. You can actually run 4 amps on one sub. 2 amps strapped on one voice coil and 2 amps strapped on the other. But I can't stress it enough the voltage output HAS to be matched! If one voice coil will end up frying and sounding like a spring or seizing up!!


But if both coils are wrapped TOGETHER how would you smoke one and not the other?


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## tagperformance

yes you can use 2 amps on either a dvc 4ohm speaker or a 2ohm speaker.


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## Oscar

*Re: two amps one sub, lets bebunk this myth!!*



thomasluke said:


> But if both coils are wrapped TOGETHER how would you smoke one and not the other?


both coils are wound NEXT to each other but they are not wrapped together in the _electrical_ sense. If you were an electron and could physically travel within the wire of a DVC where each coil was on a separate amplifier, and you started "walking" through one lead of coil #1, you would exit the other lead of coil#1---at no time would you be inside of coil #2's wire. They are physically separate.(series/parallel wiring is different---this thread isn't about that)

Another example is that if you took one lead from the outermost coil, and literally unwound it from the former, you could literally unwind that entire coil and have one super long length of straight wire, while the other coil (that was wound first) would still be there on the former completely intact.

That is how you can cause an open coil in one coil of a dual-voice-coil subwoofer if one coil is getting more power than the other. I'm not saying that it happens often, but it is possible.


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## Hispls

Worthy of consideration is the fact that when you strap amps their output resistance becomes seriesed so you lose a bit on damping factor. By all accounts unless you need to strap amps to achieve the correct ohm load one amp (gain matched from the same signal) per coil is preferred.

I've never heard of feeding a L and R signal into either coil. Seems to me like that might not be optimum


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## artv4nd3l4y

*Re: two amps one sub, lets bebunk this myth!!*



cobra93 said:


> Maybe I've missed something.
> In your first couple posts you stated that you agreed with the link you posted.
> It sound as though you're know unsure on your stance.
> 
> I assume you're referring to subs.
> Is this really relevant with the cheap class D power available today?
> 
> From your last post: "how would this degrade the life of the speaker".
> Unless the varnish/glue holding the coil windings fail and cause a short, what would cause degradation of the speaker?
> 
> I think the more important question(s) to ask here is(are): What (or how much more) distortion would be the result of sending stereo/different signals to the coils on a DVC speaker, would it be audible to most people?
> 
> I'm trying to understand your thought process here.


Yeah that was the first thing I thought of, little more than a couple hundred can get you a 2000 watt RMS 1 ohm stable monoblock. Still an interesting thread though, always am curious about things like this.


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## maggie-g

2 year old thread bump. nice.


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## cajunner

nobody actually answered this question properly, haha...

or they forgot the reason DVC subs were first implemented? Maybe it's just my thinking cap is defective, but I remember when amps were not always bridgeable, and those were used to drive normal speakers but subwoofers were new, and the size of the motor and the cones, meant that more power was needed to run them correctly.

If all you had was basic 20W/ch power limited to 14V input, the use of two channels to a single voice coil former would effectively allow deeper bass extension and output than what was available at the time.

You had a couple of companies that could make 50W/ch at that time, early seventies, but not very many were bridging capable. This too, was a place for DVC subs.

Also, since it was understood that l+r meant that you had to combine both sides to get all the bass into the sub from the source material, you could use a single sub with left plus right input, by driving separate coils on the sub.

the idea that the bass could also cancel out, wasn't pushed so much since most bass at the time was mixed to mono for LP vinyl playback, because stereo bass in the grooves would lead to needle bounce and jump-out.

with CD introduction the source material changed and the need for a stereo bass configuration became more important, while the extra uses of DVC subs for lowering impedance to wring every last watt from the amps, became hot buzz.


then, the market actually produced variable Q subs, using extra coils and technology that made it easy to buy one sub and use it in sealed, ported, or IB configuration.

that should have gone over better, like the Infinity variable Q subs, but it didn't.

The Ascendant Audio Atlas was a well designed speaker hindered by a slightly too small vent in the pole piece. I think it would have done well if someone could have connected the Q coil to a switch that also operated a servo door, so that the sub could play sealed in a smaller enclosure, then open up to a vented alignment while the Q could also change, to a lower Q in the vented box.

then, the same sub that was "tight and clear" in a sealed config playing jazz quartet, would turn into a low bass monster using a port and correct Q tuning. For the rap special, or EDM...


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## 1styearsi

i ran a RF POWER DVC 15 with 4 ohm coils back in 98.i had a punch 800a2 on each coil....


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## oabeieo

As long as the signals are in phase , dosent matter if it's stereo or not it won't matter. And the gains do not have to be matched . It will just play both signals through the movement of the cone. It's like two people carrying a heavy box . One might be stronger than the other they both carry it just fine. As long as one of the people aren't pushing down instead of lifting it will be fine

Could you imagine if someone said hey let's lift this sub box into my car and the person helping was pushing down so the other couldn't lift, I mean , it's a no brainier . 

In fact I did it on my car had 2 hd1200/1 on a sundown sad2 15 sold one of the amps now I have one amp same sub . Sub works fine


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## punkrocker

If you strap two or more amplifiers together, I think all that happens is that the audio is in-sync. between the two amplifiers. Those RCA cables don't carry a very high wattage load. Does this clarify the thread? Pretty sure at least.


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## Justang99

I’m trying to figure out if this setup would work properly:

Pioneer P99RS
2x JL XD1000/5v2 amps
1x Dual voice coil sub

I would have to run the Left rca from the P99 to the left sub input of one amp, and the Right rca to the right sub input of the other amp. Then one amp to each voice coil of the sub.
Would this work properly? My main concern is with the auto tune setup of the P99. My thoughts are the P99 would send slightly different signals to each amp and thus not hit the sub equally... thoughts? Suggestions??


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## Lycancatt

your idea will work except I'd run both rcas to the amp, then y split at the first amp and run to the 2nd amp. set gains very carefully, preferably all the way down then hit the sub out on the pioneer hard to get the output you need. higher voltage into the amps will be nice anyways.


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## Jscoyne2

https://www.youtube.com/watch?v=koCqdDXTb3s

^^^all the info you need


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## robertallinson

Nothing on that page talks about running two separate amps to one sub.


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## Evl5150

It can be done, it's not that hard. You can run two mono sub rca's, one to each amp (you can use a Y splitter on each cable if need be). Or if the amp has an output, you can run that to the second amp. I'd try to match the gains as close as possible.

OR sell the two amps and buy one BIG amp that will do what you are wanting. Would be easier to tune this way. Less wiring too.


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## WilliamS

This is the proper way to ruin a sub woofer in a spectacular way. Even if you ran 2 amps to 1 sub, try to remember the timing of the cycles say at 40hz. Thats 40 cycles per second, Im going to try to make this easy. So if either amp or signal is delayed for any reason but a fraction of a fraction second you now have 2 motors fighting each other. This can maybe generate more heat, or just rip each other apart! Running two different frequencies would be epic.

I say ignore physics and do it, perhaps you will time travel if you have enough power.


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## dumdum

*Re: two amps one sub, lets bebunk this myth!!*



Muggy said:


> Yes it can be done! I've done this many times in Db Drag. Not recommended for daily driver. You have to match the voltage output of the amps. You can actually run 4 amps on one sub. 2 amps strapped on one voice coil and 2 amps strapped on the other. But I can't stress it enough the voltage output HAS to be matched! If one voice coil will end up frying and sounding like a spring or seizing up!!


What? How does that work then? If they are not matched they don’t die period!

I’ve used 5k amps strapped on one coil and 7k amps strapped on another coil... guess what nothing died!

The only way to kill a woofer is excess heat however it’s caused or mechanical failure coils are interwound so if one gets hot the other will also, sure one can pop before the other but that doesn’t mean they need to have identical voltages or signals even


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## Holmz

WilliamS said:


> This is the proper way to ruin a sub woofer in a spectacular way. Even if you ran 2 amps to 1 sub, try to remember the timing of the cycles say at 40hz. Thats 40 cycles per second, Im going to try to make this easy. So if either amp or signal is delayed for any reason but a fraction of a fraction second you now have 2 motors fighting each other. This can maybe generate more heat, or just rip each other apart! Running two different frequencies would be epic.
> 
> I say ignore physics and do it, perhaps you will time travel if you have enough power.


The physics of it - is that electricity travels at the speed of light. There is no way it will be "slightly delayed for any reason". There is no reason.

The tweeter frequencies being well imaged at 5-20kHz proves that, and at 40 it is be easier to be perfect... which it already was at 20kHz.


The idea of running two separate frequencies on two separate coils, ignores how the motor works in a quiet profoundly


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## khlae

I'm curious to see how putting two different frequency bands into a DVC coil measures up, has anyone taken near field measurements of such a setup? I think I know how it would act but... It's a shame the only disposable woofer with two coils that I have already had the cone sacrificed or I'd try 

I've heard of people using resistors to parallel 2 amps to 1 coil, each amp first drives a series resistor then the speaker, so if the amps are imbalanced, the path from amp to amp sees both resistors and the path to speaker sees only one. But if you want more SPL, heating up a bunch of resistors is a bad way to go about it


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## Loyota86

pitchblackcls6 said:


> *Re: two amps one sub, lets bebunk this myth!!*
> 
> so it seems that few people actually read that article, some looked at it but didnt read it.
> has anyone actually tried this? im curious to see what the difference would be. how it would actually degrade the life of the speaker.
> 
> @oliver- yes you are golden because i said so, thanks for the shout out!


I have tried it,as a matter of fact I still have two power acoustic rzr2500d amps which only do 600ish watts each hooked to separate voice coils on one Walmart power acoustic gothic series 12, been that way for about 4 months now and sounds a lot better than I expected


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## MythosDreamLab

I'm sorry, this got way too technical for me, so is the myth:

Bunked?

Debunked?

Or 

Bebunked?


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## txkawboi

I'll share my results after this weekend. I'm about to try this with a Resilient Sounds Platinum 18 and 2 Kicker CXA18001s.


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## Randp07

pitchblackcls6 said:


> *Re: two amps one sub, lets bebunk this myth!!*
> 
> so it seems that few people actually read that article, some looked at it but didnt read it.
> has anyone actually tried this? im curious to see what the difference would be. how it would actually degrade the life of the speaker.
> 
> @oliver- yes you are golden because i said so, thanks for the shout out!


I did and I’m fixin to find out


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## 96jimmyslt

Randp07 said:


> I did and I’m fixin to find out
> View attachment 320637
> View attachment 320637


Bruh sell the JL stuff and get a mono.


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## 96jimmyslt

Do they make dvc mids? I want to run 2 channels to one speaker.


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## bradley85lackey

I'm hooking up to 2500 watt amps cheap Class D amps to a kicker Solo-Baric s12l7 dual voice coil running them straight to the coils any ideas any thoughts


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## 96jimmyslt

bradley85lackey said:


> I'm hooking up to 2500 watt amps cheap Class D amps to a kicker Solo-Baric s12l7 dual voice coil running them straight to the coils any ideas any thoughts


Gain match them. Listen for unloading...etc.


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## oabeieo

I have a DVC with a mrv M500 on one coil
And a XD6001 on other

different amps , different power

3 years of service and works absolutely perfect

and I’m about 300w over RMS and I use it daily for about 8hrs a day….(well actually my kids do) 

hummmm weird

sounds like a lot of this nonsense about matching amps is just nonsene

I mean , duh….. a positive waveform is a positive waveform. Especially when it comes from the same source and rca cable …. But oh no (as someone makes up some bs about different power and different positive waveforms)

lmao ….. the common sense on this topic is nonsense

Oh and did I gain match….. hell no
I left it completely whack for a year on a bet….. still works just fine

do the parameters get screwed up, yeah probably…will it damage the speaker…. No , not in my experience. Sorry
Does the bass sound good and correct….. um, yep.


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## oabeieo

The one question I think I have on the subject is 

what if you hooked one up backwards with low power

besides making it horrible inefficient, would that coil act like a field coil and raise the rms?
Haha , because I seriously doubt it would burn up.


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## 96jimmyslt

I knew a dude with 3 subs and 3 amps...lower wattage alpine too...i think the mrp m500's 

I'll stick with 1 amp for however many subs i need.

I've never understood why anyone under 5-10k rms would use multiple sub amps for one or 2 subs unless they already had the first amp and couldn't find a bigger amp to replace it. I would be concerned about one amp being off a bit, due to various reasons. 

I feel like it's just safer and easier to run a single big amp if you can, vs 2 smaller amps. At least if you're not a pro at gain matching (I'm not, lol)


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## txkawboi

Well gents, I FINALLY got around to trying this after FINALLY building a proper enclosure. End result? BIG ASS BASS from a single DVC sub and 2 separate amps. If I blow or cook any component of this setup prior to changing it ( if I ever do), I'll report back (a yr later lol). Lots of great info and opinions in this thread. As for the thread title, DEBUNKED! From an early 90s wrap song, "signing out on the symphony!"


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