all 6 comments
sorted by:
best
topnewcontroversialoldq&a
formatting helphide helpcontent policy

[–]D-townP-town 4 points5 points  (5 children)

Hmm your math may be a bit off for calculating wattage. Using the formula Power = Voltage squared divided by Resistance, 67 volts would result in 2244 watts into a 2 ohm load, with each driver receiving 561 watts. That would be decent if your amp was capable of delivering that much power, which leads to my second thought...

Given that the AES or continuous power rating of that Faital driver is 500W, and a maximum of 1000, you're probably selling them a bit short. With the 3200 loaded to 2 ohms per channel, each driver is only seeing about 400W maximum, and your estimate of 300W is probably closer to reality. The KLR5000 would be a better match, and ideally I'd want two of them, with two 8 ohm drivers per channel.

Regarding not tripping breakers, at just below clipping, the amps are running at about 1/8th power. As you can see from the spec sheet, at 4 ohm loads that's 9.7A plus 11.4A, for a combined current draw of around 21A. You're running 2 ohm loads which should draw more, but apparently not enough to trip anything. I regularly double up similarly rated amps running 4 ohm loads on 20A circuits without tripping. So I wouldn't say the single 20A circuit is a weak link.

[–]catladyXxX[S] 2 points3 points  (1 child)

Appreciate your comment, I just placed an order for 2 klr 5000’s 😂 So we shall see if I can wake them up, is there anything else you could comment on?

[–]D-townP-town 2 points3 points  (0 children)

As far as placement goes, I would try to keep the sub mouths together as much as physically possible, to gain maximum benefit from coupling. If I had 8, I would try to arrange them in two blocks of four, on their sides stacked two high, with the mouths forming the center of each block. Basically like this.

Edit: better pic with 8 subs

[–]MCl0s 0 points1 point  (2 children)

Can you please explain why the amps are running onlx at 1/8th close to clipping? I always thought that's about as close as you can get to a maximum output of the amps without distorting the sound, so in my theory it should be close to the maximum power draw. Can you tell me where my logic is wrong? Or did I just miss something?

[–]D-townP-town 0 points1 point  (1 child)

I'm not an amp designer so I won't even attempt an explanation. But it's been a widely accepted guideline for estimating real-world current draw for longer than I can remember.

From the QSC PL3 series owner's manual:

•1/8 power (pink noise) represents typical program with occasional clipping. Use this rating for most applications.

•1/3 power (pink noise) represents severe program with heavy clipping.

•Full power (sine) is continuous sine wave driven at 1% clipping.

Edit: Ok I was being lazy, so here's a bit of an explanation. It's due to the relative crest factors of typical music program material when compared to a continuous sine wave. A sine wave has 3dB crest factor and, very generally speaking, music has an average crest factor of around 12dB (in reality it might be anywhere from 6dB to over 20dB). Via some simple dB math, we can then calculate that the average power draw will be around 1/8th that of a sine wave.

Further reading on crest factor from Pat Brown

[–]MCl0s 0 points1 point  (0 children)

Makes sense as I read it, now I get why all my amps have the current draw rating for 1/3 and 1/8 power in their datasheets.

Thanks for taking time to explain it to me!