When to overpower drivers?

[Frankensuby 10+ year member]

Ok, so I know the first good reason to supply a larger headroom for speakers, and it is to reduce distortion and possibility of clipping by trying to get more than you can out of the amp.

But when is it safe to run more power to your drivers than they are rated? For example: Some people on here say that they run 300 RMS to their Germs, but the Germs are maxed at 180 watts it says. So how can you do that when is it ok to overpower drivers?

I understand that RMS, when not a sine wave, is not a constant. A 300 RMS in musical is possibly only averaging 200 RMS across an entire song, with peaks at around 300 watts, etc.

I'm just confused. Is it only possible for higher end companies like Rainbow? Do they underrate their handling on spec sheets? I would like to know because when all is upgraded on my system, I'll be overshooting my speaker power by nearly 100 RMS and my sub power handling by 300 RMS. If I could safely utilize that power, I would.

the specs:

Running 220 in to a set of Polk MMC6500 (125 RMS on spec)

Running 820 RMS into a Phoenix Gold RSD12" (550 RMS)

Right now:

Running 820 into a Phoenix Gold Xenon 10" (450 RMS in .65 cubed sealed)

Safe? Where do I need X-overs on the speakers to keep them alive?

Click to read more...

 

[Polecat 5,000+ posts]

some, underrate, plus, good clean power is better, than overpowering or clipping. on subs, it's also install dependant. Ported, use less power, sealed, you can actually add more power.

 

[jmanpc 5,000+ posts]

Definately... my 4-channel can put out 400w to my components, only rated at 150w... but they soaked it up and loved it. Just good, clean, distortion free power is fine as long as you're careful with the volume knob.

 

[n2audio 5,000+ posts]

I understand that RMS, when not a sine wave, is not a constant. A 300 RMS in musical is possibly only averaging 200 RMS across an entire song, with peaks at around 300 watts, etc.

Actually it's more like 50-100w, but you get the concept, and that's more than many.

 

[n2audio 5,000+ posts]

when you set your gain for 150 rms playing a test tone at full or near-full volume your speakers only get 150rms playing that tone at full volume.

at every other point it's something less than 150rms. Usually, much less.

I can't give you the math breakdown, but the general rule of thumb given a wide range of music is that your speakers see 10-30% of the amp's test tone output.

 

[Frankensuby 10+ year member]

So basically, if I tune at 1k Hz for fullrange, only when a note shows 1k Hz, will the amp actually give out it's true RMS?

I hope the Polks will take it //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[helotaxi 5,000+ posts]

The freq isn't the issue either. It's simply the difference between the actual recording level of the music and the reference level that you used to set the gain. 6dB is 25% of full power. If you only had 6dB of dynamic range then you would get 50 watts with peaks to 200w out of a 200WRMS amp. Since you have a lot more dynamic range than that, even with the compression that's used on most new recordings, your normal level is much more than 6dB, more like 10 or more dB, down from reference. 10dB down it 1/10th of the total power. 12dB is 1/16th the power. Get the picture?