DR280 Output

[KORTH]

I finally completed a build of 4 DR280's loaded with Delta Pro 12's and 10 1016 peizo's per cabinet. Initial listening tests are incredible regarding overall sound quality and perceived loudness. I read the Rane tech note about setting up system gain structure and Leland's note "Understanding Amplifiers and Speaker Power Rating" in the AMPS forum for setting limits to the speakers. At 15V measured at the amp output with a voltmeter, these things are painfully loud. Ignoring headroom for the moment, can I really drive them to the 400W rating of the speaker? I figure this would be around 50V or so, I can't imagine how loud that would be. This seems too loud compared to what I thought 400W was, am I damaging the speakers by driving them to the rated limits? It seems simply enough, but am I measuring the amp output wrong? Is the cab design just 'that good' regarding output/sensitivity?

As reference, I am using them with 4 T30S's, also completed this week, and driving them with a pair of Crest CC4000 amps, 2 cab's per channel, using an active crossover set at 110Hz. I've only put recorded music through the system so far, but it is intended for live sound PA support. I wanted to use the whole system for outdoor festivals covering about a city block with upwards of 3000 people. For smaller venues, which is probably 80-90% of the time, I figured a 280/T30S per side would do, but seems like overkill now that I hear how loud these really are. This system is replacing a Mackie SR1530/T24 setup which also sounds incredible, but lacks overall SPL to do larger outdoor events.

Thanks!

[LelandCrooks]

can I really drive them to the 400W rating of the speaker

Yes you can. At 15 volts into 8 Ohms thats 37 watts. At 400 watts you will be approximately 10db louder. Twice as loud. Probably too loud.

The cabs are that good. Their sensitvity makes huge amps unecessary. Cheaper to build boxes than buy 2000w amps.

[Bill Fitzmaurice]

The 400 watt rating isn't what you should drive them to, just what you can drive them to before they overheat and the voice coils melt. With most drivers power compression sets in at half power or so anyway, and if you get them to full power they're distorting horribly. That's why commercial reflex boxes need so many drivers and such big amps to do the job. But with a DR, as you're now very well aware, you don't to get to even half power before they're louder than you'll ever need them to be.