Been trying to figure this out and have been doing a good bit of searching. I want to build a couple of ported subs for light PA use, will be run with a pro audio amp. The modeled design I have right now does not hit xmax with RMS power, and the xmech is plenty.
The pro audio guys say run double the RMS power of the subs, and set limiters for no clipping - amp is comfortable and sub gets clean power all the time.
People using the pro amps for HT say that power matching the RMS rating is fine, and a little bit of clipping at a bit above RMS levels is no big deal.
Can anyone point me in the right direction or give more advice?
The pro audio guys say run double the RMS power of the subs, and set limiters for no clipping - amp is comfortable and sub gets clean power all the time.
People using the pro amps for HT say that power matching the RMS rating is fine, and a little bit of clipping at a bit above RMS levels is no big deal.
Can anyone point me in the right direction or give more advice?
So, something like the Behringer inuke 6000dsp (1700w RMS 4 ohm x 2 both channels driven) could be a good match for Dayton audio 15" Ref HO's (800w RMS), in 2.5 cubes vented, tuned to 37hz? Seems pretty excessive to me.
http://forum.speakerplans.com/behringer-inuke-nu6000-vs-kam-kxd7200-bench-tested_topic69202.html
http://forum.speakerplans.com/behringer-inuke-nu6000-vs-kam-kxd7200-bench-tested_topic69202.html
As long as you aren't tearing the speaker apart by exceeding Xmech, long term average power is what burns speakers up.
Average power can be very different for different types of music, heavily compressed sine wave like material can have 5-10 times the average LF power compared to say 1980's Steely Dan or the like. HT is generally about sound effects, which usually are fairly short, though there certainly are exceptions.
If you run double the RMS power and have limiters set for no clipping, there is still a very real potential of burning the voice coil if the amp is driven in to hard limiting, as is typical of a DJ mashing in to the red for long periods of EDM.
That said, most amps are capable of + 3 dB output when driven in to hard clipping, in the above scenario one can still burn a voice coil with a clipped amp rated at the speaker's RMS rating.
By the way, most speakers are rated using the AES standard, which uses compressed pink noise with a 6 dB crest factor (normal pink noise is around 12 dB crest factor, still less crest factor than "normal" music), which has only half the average power of a sine wave, which has a 3 dB crest factor.
Although I have tested (almost) all my woofers with sine waves at the AES rated wattage, it has been short term with resting periods between tests, so the average still is around the AES power rating or less. Some of the tests I have done not leaving enough time between tone bursts have resulted in burnt voice coils, and the amp was not clipping at all.
So the short answer about how much power is safe is "it depends".
Art Welter
That's not a PA woofer, and that amp has limiters so the level of excess is totally up to you.
It used to be the case that a PA woofers had short coils and Xmax with Xmech being 3x Xmax or more. So basically no mater what you did the driver ran out of force and the suspension could safely keep the driver from bottoming.
OTOH the HiFi subs with soft suspension and 30mm Xmax 40mm Xmech are exactly the opposite situation...
It used to be the case that a PA woofers had short coils and Xmax with Xmech being 3x Xmax or more. So basically no mater what you did the driver ran out of force and the suspension could safely keep the driver from bottoming.
OTOH the HiFi subs with soft suspension and 30mm Xmax 40mm Xmech are exactly the opposite situation...
See my post # 5, this is kind of a P.S.
Just looked at the Eminence Lab 12 specs, rated for 400 watts using the AES EIA 426 test signal (6 dB crest factor) and Parts Express wrongly label the speaker as “400 watts RMS”, overstating it’s power by 3 dB.
I’d expect the Dayton 15” Ref HO to be rated using the same AES EIA 426 test signal, be careful with an amp rated for 1700 watts, even at peak.
Art
Wow, thanks Art. Dayton gives 800w RMS on their spec sheet and web page. Given the claimed Mms of 380.6g and BL of 21.52, do you think they are rating the sub correctly for power? Seems like it should have a pretty large voice coil, and get some cooling from the aluminum cone?
I would suspect the speaker is 800 watts AES 426, which would be 400 watts RMS.
Still, that would be 3 dB more power handling than the Lab 12, and I have not burned any Lab 12s using about 2000 peak watts.
That said, I also have never used my Lab 12s for long periods of EDM
.Art
No mention here of talk about the level in the space and frequency. You need sufficient power to product sufficient sound levels in the worst case setup, and add some headroom to keep the amp happy. As was stated, "it depends"
For PA use, go buy PA speakers, not home theater speakers. Efficiency is almost everything.
For PA use, go buy PA speakers, not home theater speakers. Efficiency is almost everything.
I'd agree about going with a stronger, un-clipped amp.
There is no DC in clipping of musical signals, the speaker is always seeing alternating (+/- ) signal.
The speaker heats in response to average power, there is more power in a square wave of the same amplitude as a sine wave, a fully clipped signal may approach double (+3dB) the power an amp delivers over it's rated power.
Valid point...this will be for portable use in private house parties and limited outdoor use. Not real pro use, but a powerful stereo that can be transported and setup quickly. Sound quality is nearly important as output. I've modeled many pro woofers, and found that the 15" HO can give nearly as good of sensitivity in a small ported box with good extension to 35hz. Roughly 16x22x19 is what I'm looking at. They seem like they are pretty beefy subs and people work them hard in car and HT use. I'd really like to have some huge bass horns but don't want to transport them.
For the rest of the system I just picked up some Peavey Impuse 100's. They sound great, I was running them off a musical fidelity A2 and analog parametric EQ this weekend, sourced by a sansa clip+ with flac files. Have a Adcom GFA-555 I intend to power them with for PA use. So after a USB dac, the tops could have a full analog chain. The impulses will get taken apart and internally braced and damped. It would be nice if i could use a dsp pro amp on the subs so I wouldn't have to add a standalone crossover. I would like to build pole mounts into the subs to fly the tops over them, using heavy steel poles ~50lb each.
Will also have a 12v setup with an alpine class-d amp and SLA batt, intended to use with the mains and a single sub.
If I can hit 110 db in a 1000 square ft room, I will be pretty happy with that.
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Think DrDyna is stating that extreme clipping is basically the same as the square wave Art, at a full clip you basically have alternating bursts of DC..?
Thanks I'm here all week
The NU6000 is basically two bridged NU3000's in one chassis, so you can't bridge the NU6000 but it is 2kw per channel @4Ω...
Thanks I'm here all week
The NU6000 is basically two bridged NU3000's in one chassis, so you can't bridge the NU6000 but it is 2kw per channel @4Ω...
Yes, 1700w @ 4 ohms per channel, both driven, into each sub.
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