# What's the most you've ever overpowered your subs.



## Fricasseekid (Apr 19, 2011)

So many people know that a subwoofer can handle an RMS signal that's substantially stronger than what its rated for, as long as the signal is clean. But there must be a statute of limitations right?

So what the most you've ever overpowered your subs and how long did they last?


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## Fricasseekid (Apr 19, 2011)

I just recently blew a Polk Audio MM. I had two of them rated for 450 watts apiece, and I had them wired @ 1 ohm to a 1500 watt amp. Granted I had the gains dialed down to around 1000 watts but sometimes with the bass cranked and song dynamics I'm sure they were getting ALOT more power. They lasted about two weeks, but damn they sounded good!

I can't say for sure my signal wasn't clipped cause I don't own an o-scope.


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## hottcakes (Jul 14, 2010)

i've two '03 series dvc 4ohm kicker cvr 10" subs wired to 1ohm running off a rockford 1000 (rated, tested power i don't know) watt amp. cannot say for sure where the gain is set since i tuned it by ear, but i should probably turn it up so i can turn down the sub pre-out level on the HU. 

i'm not even sure what the subs are rated at, but they still work. too lazy too look, but i'm going to guess 300watts a piece, maybe 350. can't remember the low pass either, perhaps 50hz @ 18db. i kinda do want to blow them up so i can get something "better," too bad i don't have cash sitting around to do so.


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## subwoofery (Nov 9, 2008)

The box makes the difference... I made a test box with 2 x Audiopulse Epic 8" and sent 3000 rms... Still going strong - and still playing in my friend's shop. Lot's of fun especially when we demo the 8s with a big fat 18" in front - just to mess with customers 

Ohh yes, for your info, this is an SQ enclosure  
http://www.diymobileaudio.com/forum/1183365-post32.html

As stated in another post, I never trusted the MM to have 1" of Xmax one-way... Especially with the SR line only getting 0.64"... 
Your box was vented right? Did you have a subsonic on? 

Kelvin


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## BuickGN (May 29, 2009)

I think it varies wildly on the sub used. I've seen many people pushing 1,000w to a 12W6 with no issues. Some subs seem to have very little safety built in. 

Enclosure of course has a huge effect. While the 12W6 might take 1,000w thermally, it can only take 250w max in free air. So who knows, in a large 3 cube box, that 1,000w might mechanically destroy it.

I've hit my IB15s with a 500w thermal limit with the full 1,000w at 20hz by accident once. No bad noises, nothing bottomed or anything. I think they are made to not commit suicide when over powered but rather the motor strength gets down to a point at huge excursion where it's weak and the suspension tightens to keep it from hurting itself. Other subs don't have this built in. The 12W6 will mechanically beat itself to death if you exceed xmech.

How did the Polks fail, thermally or mechanically?


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## Fricasseekid (Apr 19, 2011)

subwoofery said:


> The box makes the difference... I made a test box with 2 x Audiopulse Epic 8" and sent 3000 rms... Still going strong - and still playing in my friend's shop. Lot's of fun especially when we demo the 8s with a big fat 18" in front - just to mess with customers
> 
> Ohh yes, for your info, this is an SQ enclosure
> http://www.diymobileaudio.com/forum/1183365-post32.html
> ...


No, it was sealed. But I still had a subsonic on it @ around 20 Hz. 

I doubt it has that much xmax, but it deffinitely has the x-mech. The only thing I don't get is when I was driving these things really hard is when they sounded the best. If I was pushing them so far beyond xmax shouldn't I have been getting some god awful distortion? Maybe I don't know whatyo listen for with sub distortion.


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## Fricasseekid (Apr 19, 2011)

BuickGN said:


> I think it varies wildly on the sub used. I've seen many people pushing 1,000w to a 12W6 with no issues. Some subs seem to have very little safety built in.
> 
> Enclosure of course has a huge effect. While the 12W6 might take 1,000w thermally, it can only take 250w max in free air. So who knows, in a large 3 cube box, that 1,000w might mechanically destroy it.
> 
> ...


Thermally. Unless they mechanically went far enough to lose linearity and this caused the coil to rub... ? 

That can happen right?


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## BuickGN (May 29, 2009)

Fricasseekid said:


> No, it was sealed. But I still had a subsonic on it @ around 20 Hz.
> 
> I doubt it has that much xmax, but it deffinitely has the x-mech. The only thing I don't get is when I was driving these things really hard is when they sounded the best. If I was pushing them so far beyond xmax shouldn't I have been getting some god awful distortion? Maybe I don't know whatyo listen for with sub distortion.


Maybe you like the warm sound of distortion. Personally I do.

It varies from sub to sub but I couldn't hear any audible distortion or change in sound when pushing my 12W6s right up to their mechanical limits. 16.5mm is their xmax and 25mm is the xmech. It's a pretty large difference in xmax and xmech and I couldn't hear any distortion.


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## Fricasseekid (Apr 19, 2011)

BuickGN said:


> Maybe you like the warm sound of distortion. Personally I do.
> 
> It varies from sub to sub but I couldn't hear any audible distortion or change in sound when pushing my 12W6s right up to their mechanical limits. 16.5mm is their xmax and 25mm is the xmech. It's a pretty large difference in xmax and xmech and I couldn't hear any distortion.


I thought throwing the coil out of the magnetic gap can cause serious problems?

Perhaps I do like that sound. So how does one achieve that safely?


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## madmaxz (Feb 11, 2009)

I gave my idq12v3 (500rms) about 1000 each and they were fine. I'm running my arc black to at it's rms 500-600 @8 ohms Im not sure if I should give it the 1600- 1700watts my RD t1500 can do a 2 ohms.


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## BuickGN (May 29, 2009)

Fricasseekid said:


> I thought throwing the coil out of the magnetic gap can cause serious problems?
> 
> Perhaps I do like that sound. So how does one achieve that safely?


As long as you don't hit xmech, you're not throwing the coil out of the gap or hurting anything. Xmax is usually the amount of excursion it takes to hit 10% distortion (some like JL use a higher standard than 10%) but most subs will have more excursion, some significantly more excursion before they hit their mechanical limits (xmech). The 12W6 has an xmax of 16.5mm and xmech of 25mm. My IB15s have an xmax of 18.5mm and an xmech of 25mm.

You can push the sub past xmax safely assuming you don't exceed the thermal limits. The xmech number will tell you how far you can push it before you do mechanical damage. Some subs sound terrible after xmax. Some sound great well past xmax and have a lot more usable range than the xmax figure would indicate.


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## Fricasseekid (Apr 19, 2011)

BuickGN said:


> As long as you don't hit xmech, you're not throwing the coil out of the gap or hurting anything. Xmax is usually the amount of excursion it takes to hit 10% distortion (some like JL use a higher standard than 10%) but most subs will have more excursion, some significantly more excursion before they hit their mechanical limits (xmech). The 12W6 has an xmax of 16.5mm and xmech of 25mm. My IB15s have an xmax of 18.5mm and an xmech of 25mm.
> 
> You can push the sub past xmax safely assuming you don't exceed the thermal limits. The xmech number will tell you how far you can push it before you do mechanical damage. Some subs sound terrible after xmax. Some sound great well past xmax and have a lot more usable range than the xmax figure would indicate.


I'd love to send my other Polk MM to Erin for klippel but I think he isn't doing the testing right now. 

I'm think of just scrapping the two Polk for two Dayton HO 12s. They should be able to take the whole 1500 watts and then some.


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## subwoofery (Nov 9, 2008)

Fricasseekid said:


> I'd love to send my other Polk MM to Erin for klippel but I think he isn't doing the testing right now.
> 
> I'm think of just scrapping the two Polk for two Dayton HO 12s. They should be able to take the whole 1500 watts and then some.


What was the size of your sealed box again? For the 2 x MMs... 

Also, if you plan to go Dayton, try to listen to one first and see if you like a low distortion. Distortion adds warmth to the sound and can sound pleasing to the ear... 
I recommend you use a JBL Power P 1222/1224 - they are cheap and sound really good... 
If you really need a shallow driver, I don't see anything (spec wise) that can beat the Type R one lately - never used one though... 

Kelvin


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## Fricasseekid (Apr 19, 2011)

subwoofery said:


> What was the size of your sealed box again? For the 2 x MMs...
> 
> Also, if you plan to go Dayton, try to listen to one first and see if you like a low distortion. Distortion adds warmth to the sound and can sound pleasing to the ear...
> I recommend you use a JBL Power P 1222/1224 - they are cheap and sound really good...
> ...


The Alpines cost so much though and I didn't like the models.

The Polk were in a sealed box just shy of 3 ft^3 before speaker displacement.


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## subwoofery (Nov 9, 2008)

Fricasseekid said:


> The Alpines cost so much though and I didn't like the models.
> 
> The Polk were in a sealed box just shy of 3 ft^3 before speaker displacement.


FYI, the Dayton is a single 4 ohm driver. So 2 will give you a 2 ohm load at the amp... 

Here's the 2 x MM in 3cuft and the 2 x P1224 in 2cuft (subsonic set to 20Hz @ 12dB/oct slope on both) powered by 1500rms: 









Everything looks pretty much the same except for excursion (the MM has a bit more). Knowing the Xmax for the JBL, I can tell you that with that alignment, subsonic and power - mechanically the JBL is safe... 
Thermally, the JBL and the MM both see 800rms max (400rms for each sub) 

So IMO, you failed your MM mechanically since the MM have a 425rms power rating... unless you were clipping. You leave the bass boost off right?  

Kelvin


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## Fricasseekid (Apr 19, 2011)

subwoofery said:


> FYI, the Dayton is a single 4 ohm driver. So 2 will give you a 2 ohm load at the amp...
> 
> Here's the 2 x MM in 3cuft and the 2 x P1224 in 2cuft (subsonic set to 20Hz @ 12dB/oct slope on both) powered by 1500rms:
> 
> ...


They make a DVC Dayton. 

I had the bass boosted a couple decibels @30 hz just to get a better low end response. But it shouldnt have been clipping cause I set my gains down to 1000 watts (31 volts) but set them @ 40 hz where the amp had the most output.


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## subwoofery (Nov 9, 2008)

Fricasseekid said:


> They make a DVC Dayton. Good to know
> 
> I had the bass boosted a couple decibels @30 hz just to get a better low end response. But it shouldnt have been clipping cause I set my gains down to 1000 watts (31 volts) but set them @ 40 hz where the amp had the most output.


Ok... How much is "a couple of decibels"? Coz you might have overdriven your subs that way, even with the gains set back to 1000rms. Let me show you: 








Xmax figures... See the *RED* (1000rms) with a boost of 3dB @ 30Hz - the boost increases the Xmax even more. 3dB also means twice the power applied (theoretically)... 









Now both your subs see 510 watts instead of 400... Doesn't seem like much but may be enough to cook coils if the cooling system is not up to par... 

Again, how much is "a couple of decibels"? Coz IMO, 3dB seems like a lot already... 

Kelvin


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## Fricasseekid (Apr 19, 2011)

subwoofery said:


> Ok... How much is "a couple of decibels"? Coz you might have overdriven your subs that way, even with the gains set back to 1000rms. Let me show you:
> 
> 
> 
> ...


Well my bass boost goes from 0-12 and I had it set around 2. I had figured for 5 db in my models but that was considering 1" of xmax so I went a little more conservative. 

I guess I'll also mention that I was listening to Bass Mekanik when the speaker popped.


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## Fricasseekid (Apr 19, 2011)

Also, if the JBLs and the Polks look so close why would you think the JBLs could handle the abuse?


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## cubdenno (Nov 10, 2007)

You may have done a bit of both. Playing tones that are likely recorded at max levels AND pounding your system..... Watch a voicecoil get a constant 1000 watts and see what it does.


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## subwoofery (Nov 9, 2008)

Fricasseekid said:


> Also, if the JBLs and the Polks look so close why would you think the JBLs could handle the abuse?


Coz we know for sure the real Xmax for the JBL... Also, the JBL has a bigger voice coil than the MM (3" VS 2") - so it won't fail thermally. Since you don't have enough low end (hence the bass boost use), you need a sub with a higher Xmax rating... 
In sealed enclosures, Xmax is *KING*. Don't know your budget but you might need to look into those: 
WoofersEtc.com - SA-12 D4 - Sundown Audio 12" 600W Dual 4-Ohm SA Series Subwoofer 
WoofersEtc.com - SWR-1243D - Alpine 12" DVC 4-ohm Type-R Subwoofer 
https://ssl.perfora.net/www.ficaraudio.com/sess/utn;jsessionid=154e7025cc522b2/shopdata/0050_Speakers/0040_SSD/product_overview.shopscript 

Now, if you don't have enough low end in your sealed box, you might also consider going ported. 

Kelvin


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## Fricasseekid (Apr 19, 2011)

Ported was the plan with the Daytons.


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## BuickGN (May 29, 2009)

VC size is not the only thing that determines power handling. My Dyn 6.5" should have 1,000w power handling if that were the case with their 3" VC lol.


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## subwoofery (Nov 9, 2008)

BuickGN said:


> VC size is not the only thing that determines power handling. My Dyn 6.5" should have 1,000w power handling if that were the case with their 3" VC lol.


True... But it does tell you some. Look at the Ultimo 8... It easily has the highest RMS rating @ 800 rms. That is due to its oversize 5.1" voice coil... What voice coil size doesn't tell you though is how much SPL you can achieve 

Knowing JBL and reading up on their sub tech, they did manage to keep the voice coil cool during normal listening... What should really stop you from sending 1500 watts to 1 is the excursion. 

Kelvin


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## BuickGN (May 29, 2009)

subwoofery said:


> True... But it does tell you some. Look at the Ultimo 8... It easily has the highest RMS rating @ 800 rms. That is due to its oversize 5.1" voice coil... What voice coil size doesn't tell you though is how much SPL you can achieve
> 
> Knowing JBL and reading up on their sub tech, they did manage to keep the voice coil cool during normal listening... What should really stop you from sending 1500 watts to 1 is the excursion.
> 
> Kelvin


I know, I'm bored and just giving you a hard time. I think it is a little interesting how the Dyns are actually rated at something crazy on transients like 1,000w or so. I wonder if that is due to the very large VC. Maybe it can absorb a few milliseconds of extreme power without burning up. I know the reason for the very large VC is the breakup nodes of the cone but maybe it does have some other small advantages.

A little more on topic, I've sent mine that are rated at around 150w?!? over 300w and they handled it fine but they were high passed at 80hz.


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## eltico7213 (Oct 26, 2011)

i had my DD 9512 play for months at 3000w off an audiopipe ap3k... after 8 months it finally gave out, so i got a recone and a dd m3a at .5 ohm. im going to measure imp rise and measure the exact power going to it now, but im expecting about 2kw. rms off the DD is 1500, but i love how easily these subs can go way over... if 180+ db could be hit off their 18' from 24kw, you know these subs can hold up.


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