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New Generation "High Powered" MI Level Speakers
DBA:
Looking at the specs for new(ish) generation top tier MI loudspeakers (take Peavey QW or SRX for example) I can't help but think some of the power handling figures are marketing fluff.
For Example:
JBL SRX 715 is rated Passive: 800 RMS/1600 Program/ 3200 Peak
Peavey QW2: 1600 watts program, 3200 watts peak
So, now that we have an apples to apples loudspeaker comparison that have similar output, sensitivity, frequency response, etc..etc and technically should be a close drag race between them.
Does this mean for either of these two cabinients, the LARGEST PLX amp (let's just agree for a moment that this amp line is suficient to match most MI level use..because it is) is "ONLY" good for 700watts RMS at full tilt on either of these speakers wich is barely, if not even, their RMS power levels?
Ok, so now to the real world. What does this really mean? Does it mean that neither of these loudspeakers can be pushed to acceptable levels for a rock band or DJ use with one of the biggest MI level amps you can buy? Or does it mean, they will get loud enough without catching on fire? Does it really mean that a DJ could take a PLX 3402 and let it rip on either of these cabinents constantly in "clip" or "peak" and never burn up anything? I mean, that's what the RMS figures suggest right? I just find it all hard to believe, or maybe I have been out of it for too long.
Is there really that much to be gained by hitting these speakers with a solid 1600 watts each? If manufactures are making simply trying to make bulletproof speakers, I am for that. If they are truely making speakers to hold this much power to get slightly louder, then I don't really see the point in having to have 6,000 watts on tap to power a pair of them.
This question is just a general observation to some of the huge power figures on speakers these days.
Maybe, I should have just asked "What do you power your SRX and similar high powered cabs with and how do they sound".
Steve Ferreira:
This past weekend I powered 2x712s with an Itech 8000. I didn't use all that power, but they sure did get up and go. I also use the rms limiters in the ITechs just to make sure nothing blows up.
Any of the speakers you mentioned will take that kind of power and sound good. By matching the rms with an amp will not give you enough headroom for transients to "get through". You don't want to clip an amp into any speaker.
As for your last question:I power up srx 725s and 728 with IT8000s. That's a 1200 watts rms @4 ohms cab on a 4000 watts per ch amp.
Tracy Garner:
My main go to rig is 2x IT8000 with 4x 725/728. It runs at 2 ohms on 2 20amp circuits (sometimes even 1-20 amp circuit with control). If I do only 1 bottom/top per side, I don't change any amp settings. Sometimes, I hook straight up into a DJ mixer and other times I will use up to a 40 channel console for bands/choirs. I'm enjoying a pretty versatile setup I can move myself except for the occasional endless staircase. Even then, I usually enlist a security guy instead of the second helper. When I do need a helper in these cases, its more about needing production help than moving help.
I'm really not a big fan of the sound of a 725 overall but for the weight and power, and even reliability, its hard to beat.
Paul G. OBrien:
--- Quote from: Whit Hutchinson on February 04, 2011, 03:39:23 PM ---Looking at the specs for new(ish) generation top tier MI loudspeakers (take Peavey QW or SRX for example) I can't help but think some of the power handling figures are marketing fluff.
For Example:
JBL SRX 715 is rated Passive: 800 RMS/1600 Program/ 3200 Peak
Peavey QW2: 1600 watts program, 3200 watts peak
Ok, so now to the real world. What does this really mean?
--- End quote ---
It means the manufacturers tested these speakers with an 800w signal that had momentary peaks(maybe only miliseconds) of up to 3200w.. and they survived. That may sound like a lot but you have to remember these 3 numbers represent the last 6db of power handling where most of the power compression and distortion occurs, or where the output gains from adding more power are dimishing fast.
--- Quote from: Whit Hutchinson on February 04, 2011, 03:39:23 PM ---Does it mean that neither of these loudspeakers can be pushed to acceptable levels for a rock band or DJ use with one of the biggest MI level amps you can buy?
--- End quote ---
Not unless you consider close to 130db output from a pair of speakers unacceptable, because that is what they will produce with about 700w each
--- Quote from: Whit Hutchinson on February 04, 2011, 03:39:23 PM ---Does it really mean that a DJ could take a PLX 3402 and let it rip on either of these cabinents constantly in "clip" or "peak" and never burn up anything?
--- End quote ---
Absolutely not, but it's because of what happens to an amp pushed deep into clipping, it produces a squashed(compressed) signal with heavy high freq distortion content that will be at quite a bit higher output level than what the amp is spec'd to produce, and that is something speaker systems in general aren't designed to handle.
--- Quote from: Whit Hutchinson on February 04, 2011, 03:39:23 PM ---Is there really that much to be gained by hitting these speakers with a solid 1600 watts each?
--- End quote ---
Yes.. as some of the other responders have already indicated, but it depends upon the source material and what you do with that 1600w. It should be used as headroom to cover momentary peaks without clipping the amp, you cannot push sine waves at this power level.. for that you have to keep it at the RMS rating.
Bob Leonard:
The question of amplifier rating has been discussed many times in the past and I have yet to see anyone come up with a better rule of thumb than the rule of thumb which has been used for the past 40 or so years.
If you want your speakers to perform to their potential then;
Take the RMS long term capability of the cabinet and multiply it by two. In the case of you SRX example, which is not considered an MI or entry level cabinet your amplifer should provide.
2 x 800 watts = 1600 watts. 1.5 can be substituted for 2, and an amplifer which provides 800 watts may work fine depending on the application and as long as the amplifier does not clip.
In most cases it is usually long term clipping caused when under powering the cabinet which destroys the drivers, not the instantaneous peaks the cabinets are designed to handle at 1600 or 3200 watts when using a properly sized amplifier that does not clip.
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