Over powering a subwoofer, can you and by how much if so?

[mikeyt]

I was reading some forums and watching some videos of guys who were throwing excessive power at some subs. Now mind you these were competition monster SPL pounding subwoofers so I wouldn't doubt they are built to be abused, however even they have limits. One guy was driving a 2500 watt rms sub with a 5k rms amp running at 95% he said. So that's 4500 watts ground pounding the heck out of the speaker and it was devastating IMO, and I know that's going to eventually burn up. However, I've seen different things to say that a subwoofer, not sure about coaxes or anything else, that is a quality product, not some Dollar Store special, has a built in safety factor for this purpose of approximately 15-20%. Not sure how true that is, so that's why I ask. For example sake let's take a JL Audio 10TW1-2 rated at 300 watts rms, and it will be driven by an amp at 2 ohms that puts out 600 watts rms. I'm using this shallow mount as an example for someone trying to get more output out of a confined space with only being able to use one driver. If you were to dial that in mathematically at 360 watts rms (20%) over powered would the speaker be fine, do manufacturers build in a safety factor for this? I understand rms is approximately 80% of max power, however as I understand it, max power is peaked at resonant frequency for a brief period of time and isn't sustainable consistently. I could be wrong, which I probably am...lol

[Weigel21]

Even if you were to use an amp capable of 600RMS and set the gain for such, you'd only see said power when using the volume level used when the gain was set and with source material recorded at or stronger than the source material used when the gain was set.

Now I'm not trying to tell you to do such, but I've known people to use amps capable of feedind their sub setup 1.5 times it's rated power handling without any short term issues.

Heck, I've got a pair of 130RMS 6.5" JVC woofers in a bandpass enclosure that I powered with a JBL MS-A5001 that had it's gain setup for 400RMS with a -3dB test tone for when I was using my 15" Polk. I ran it for a good year without any issues before putting the 15" back in. I did the swap to have trunk space while working out of town and needing to carry my belongings, passengers, and their belongings for the work week.

I did at one time crank the system up with a bass heavy track and found that the little bandpass setup didn't like such levels of power, but regardless, it didn't blow nor did it seem to incur noticeable dage from the nearly minute or so I played it pushing it's limits.

My point, unless you are really trying to squeeze everything you can out of that sub, you probably aren't going to have any real issues.

Still, take this all with a grain of salt, my luck and others I've known may have been better than what yours may be if you opt to really push the limits of the sub.

JL used to have a power rating diagram, in which it showed the optimum power and as you went beyond it, it eventually said warranty voided.

Also keep inind that exceeding the rated power of a driver won't yield much more in terms of output, unless we're talking about SPL burps. It takes doubling the power to get 3dB in gained output, so yeah, you'll hardly get a noticeable gain giving that 300RMS JL 600RMS.

If output is what you're after, then don't buildva setup that is going to struggle to give you what you want.

Going back to what you said before though, giving 20% power over rated isn't going to give you any noticeable gain in output, so it's pretty much a wash for anyone not chasing numbers.

[mikeyt]

I don't plan on doing any of that. There is a wealth of knowledge out here that's why I ask. When I come across things like this or see stuff that jogs a memory of something I faintly remember, I put it out here, I know some of it may be silly but tat's okay.

[Justin Zazzi]

I was reading some forums and watching some videos of guys who were throwing excessive power at some subs. Now mind you these were competition monster SPL pounding subwoofers so I wouldn't doubt they are built to be abused, however even they have limits. One guy was driving a 2500 watt rms sub with a 5k rms amp running at 95% he said. So that's 4500 watts ground pounding the heck out of the speaker and it was devastating IMO, and I know that's going to eventually burn up.

This is such a frustrating question to answer. For example how was this 2.5kw subwoofer rated? Was it tested using EIA-426B standard which means it should be used with a 2.5kw amplifier but it is actually rated to handle half of that power for half a day? Was is tested using AES2-2012 which means it can actually handle 2.5kw of rms power for 2 hours? Was it rated by some other standard that means ... something else? How was the guy in the video sure he was using 95% of the 5kw amplifier? How long did he play it, and what material was he using? Was is a sine wave tone blasting for three seconds or was it an SPL specific bass "music" track or was it AC/DC song recorded a few decades ago? What was the crest factor of the music and was the combination of the song and the enclosure allowing the cone to move enough to exchange enough air in the motor structure to keep the voice coil cool?

Too many variables to give you any kind of solid answer!

However, I've seen different things to say that a subwoofer, not sure about coaxes or anything else, that is a quality product, not some Dollar Store special, has a built in safety factor for this purpose of approximately 15-20%. Not sure how true that is, so that's why I ask.

I've not heard the 15-20% safety factor before and it sounds unreasonably small even for proper speakers from a reputable company. I would argue that dollar-store speakers have a negative safety factor because many of those numbers you find at flea markets and discount stores are wildly optimistic.

For example sake let's take a JL Audio 10TW1-2 rated at 300 watts rms, and it will be driven by an amp at 2 ohms that puts out 600 watts rms. I'm using this shallow mount as an example for someone trying to get more output out of a confined space with only being able to use one driver. If you were to dial that in mathematically at 360 watts rms (20%) over powered...

Gotta stop you right there. You cannot dial in precisely 360w rms like this. The amount of power delivered to the speaker is dynamic and it will change the moment your song changes from a verse to a chorus, and especially when you play a different song. You could, in theory, dial in the power to exactly 360w on one song and then play another song and it will deliver 32 watts instead. Unless you are playing something very repetitive like the EIA-426B test noise or a pink noise with a specific crest factor like in the AES2-2012 test, then you can't dial it in like that.

do manufacturers build in a safety factor for this?

Sometimes. But if they told you then would it still be a safety factor?

I understand rms is approximately 80% of max power, however as I understand it, max power is peaked at resonant frequency for a brief period of time and isn't sustainable consistently. I could be wrong, which I probably am...lol

Why do you believe these things? Peak power usually means whatever the manufacturer wants it to mean. Sometimes it is a number that makes their product look better when you're sorting it on Crutchfield and sometimes it is a number that is specified from a very specific testing standard. You will often never know unless that standard is called out in their literature.

The JL 10TW1 for example: I did not find any standards specifically mentioned on the website or the user manual so it is hard to say where the 300w rms number comes from. They do mention that:

the power levels listed in the above chart represent continuous (RMS) amplifier power per woofer and assume
that the user will regularly make full use of that power without drastically overdriving the amplifier(s).

So it seems like the 10WT1 is rated at 300w rms continuous or they recommend a 300w amplifier depending on how you read the verbage. These mean two very different things.



I used to work at Eminence and I designed their new power testing room so I'll use their new Tour Grade 21" subwoofer as an example of something easier to interpret. The badge says "2500w AES power" which means an amplifier played pink noise with a 6dB crest factor and an rms power of 2,500 watts for 2 hours and the woofer had no damage or significant change in performance. Think about that for a moment though: 2,500w with a 6dB crest factor means a 10kw amplifier had to be used for this test. The rating also says 5000w program power which means you can safely use a 5kw amplifier to play music during an event. So this 2,500w woofer can handle a *much* larger amplifier if you play music but that's only clear because the testing method is clearly defined!

[mikeyt]

Thanks Justin, that's why i asked this question. You bring objective quality evidence to the table to dispel folk lore. This was a youtube video of guys at some bass off or something like that and the guy who was filming was asking these questions, them he played some "bass trac"/rap song that made the truck vibrate the earth, there was NO science or technical specificity involved that I could see, no shred of how anything was measured or verified, only what he said. I was taking that, if that were true, how could he be running just about twice the power to a subwoofer that could only handle half as much and not blow up after all that abuse and be able to run it constantly. Is that you sniffing the fine bouquet of a coil?

[Justin Zazzi]

I'm sorry for overlooking Weigel21's post! It has some great points.

Thanks Justin, that's why i asked this question. You bring objective quality evidence to the table to dispel folk lore. This was a youtube video of guys at some bass off or something like that and the guy who was filming was asking these questions, them he played some "bass trac"/rap song that made the truck vibrate the earth, there was NO science or technical specificity involved that I could see, no shred of how anything was measured or verified, only what he said. I was taking that, if that were true, how could he be running just about twice the power to a subwoofer that could only handle half as much and not blow up after all that abuse and be able to run it constantly. Is that you sniffing the fine bouquet of a coil?

I also meant to say that some friends having fun on YouTube is great and I don't mean to discount any of it. If they enjoyed it, awesome!

And yes that is me inspecting a voice coil in my picture haha : )

[mikeyt]

You are correct sir. Inspecting, yeah that's rich...haha I sent you a pm. Fine like wine I see.

[ckirocz28]

I was reading some forums and watching some videos of guys who were throwing excessive power at some subs. Now mind you these were competition monster SPL pounding subwoofers so I wouldn't doubt they are built to be abused, however even they have limits. One guy was driving a 2500 watt rms sub with a 5k rms amp running at 95% he said. So that's 4500 watts ground pounding the heck out of the speaker and it was devastating IMO, and I know that's going to eventually burn up. However, I've seen different things to say that a subwoofer, not sure about coaxes or anything else, that is a quality product, not some Dollar Store special, has a built in safety factor for this purpose of approximately 15-20%. Not sure how true that is, so that's why I ask. For example sake let's take a JL Audio 10TW1-2 rated at 300 watts rms, and it will be driven by an amp at 2 ohms that puts out 600 watts rms. I'm using this shallow mount as an example for someone trying to get more output out of a confined space with only being able to use one driver. If you were to dial that in mathematically at 360 watts rms (20%) over powered would the speaker be fine, do manufacturers build in a safety factor for this? I understand rms is approximately 80% of max power, however as I understand it, max power is peaked at resonant frequency for a brief period of time and isn't sustainable consistently. I could be wrong, which I probably am...lol

Most quality subs will handle around double their rms power rating, when playing music, hence the fairly common "max power" or "program power" ratings. Because music doesn't produce the same constant power level as the sine waves used to measure power handling. You can significantly over power a sub while playing music, but when it comes to test tones you need to be very careful.

[mikeyt]

Ahhhhh, I see said the blind man. Makes sense that fluctuations would not produce the same power and the subwoofer isn't subject to that during a sustained time period, and also like you said the waves are different. However, I won't "overdrive" my stuff, I can't afford to keep replacing it...haha

[mlekk]

A 10W6 on 1500 watts in a HO enclosure from JL is still running after 3 years - the "rumble"