Crown+DRPA2+JBL

rickcollette

I have the following equipment - I want to use this for a dance floor. The floor itself is 625 square feet. The DJ booth is at one end of the tavern, the bar is at the other, they are facing each other, the space is 25feet wide and 76 feet long. Ceilings are about 17 feet high. Mostly Electronic music.

Crown XTi 4000
Crown XTi 4000
Crown XTi 4002
Crown XTi 4002
Crown XTi 6000
DBX DriveRack PA2
JBL SRX725
JBL SRX725
JBL SRX725
JBL SRX725
JBL SRX828S
JBL SRX828S
JBL SRX828S
JBL SRX828S
JBL SRT815S
JBL SRT815S
JBL SRT815S
JBL SRT815S

Being dance music, and loudness and coverage is the primary goal here, what would be the best setup using this equipment?
I mostly work in a production studio environment, so this is pretty new to me - but I am super happy to learn new stuff.

rickcollette

Maybe I am asking the wrong question here.

the impedance on the SRX815 says 8ohms.
I have several XTI 4000/4002 amps.

Should I be running a left side output of my source into an XTI4000 2400W bridged mono @ 8 ohms to two SRX815's (into speak 1, out of speaker 1 and into speaker 2) and a second set the same for the right side?

or

Should I run a single XYI4000 stereo mode at 8ohm 650W left side to speaker one, our of speaker 1 and into speaker2, the do the same for the other two speakers on the right side?

Or something completely different?

nojoco

Looks like you have a lot of equipment for a small dance floor. Do you plan on elevating the speakers in the ceiling over the dance floor? 2 tops and 2 bottoms could easily cover the dance floor, even for EDM. If you want to use more speakers (especially subs), you could be in a problem with standing waves in the room with a 25ft wide area. The standing waves are a physics issue and adding more subs will not fix the problem. Having too many subs can introduce audio quality issues.

I would load the amplifier channels with 8-ohm loads (which is usually one speaker per channel). 4-ohm loads may be better, but for EDM (due to heavy low sustained tones), that could place a heavy load on amplifiers, especially if the amps do not have an adequate electrical source. Does your bar have adequate circuits to support EDM music? Also, pertaining to your last suggestion, if you are connecting speakers (from one speaker out to another), you are creating a 4-ohm load (by using 8-ohm speakers). For bridged mono operation, it's usually best not to load a single mono channel below 4-ohms. Referencing your first suggestion of 2400W bridged mono at 8 ohms, by placing 2 SRX815 speakers on that channel (parallel connections), you are actually creating a 4-ohm load on the amp. A lot of amplifiers do not like 4-ohm loads while in bridged/mono!

rickcollette

Awesome! Thank you so much. The equipment is available, but not required to be used. We could even rack up a second set to use for events. I like a lot of back up as well. In case something goes sideways.

We will be hanging the 815's ; I was thinking one at each corner.

So for the 815's - I could do 650W and 8ohm load. 2 channels/speakers per amp, using 2 of the 4000's

For the subs - these are the SRX828S ; should i use those stacked (one bin on top of the other) and use the XTI 6000 in 8 ohm stereo at 1200W per channel?

Or is there a better solution here?

rickcollette

Oh. My gosh. So - I tested the 815 at 650w per channel stereo. Just a single pair.. the sound is so much better than the powered speakers I was using prior. Once I get the baseline setup and configured, I would love to try bi-amping to see if I can get some really solid clarity from it.... as I mostly spend my time in production, I am likely to apply what I do there: Subtractive EQ until its the way I like it. Also.. I have 51 year old ears, so likely to have a younger human come in and make sure I'm not sending massive amounts of ultra-high freq into those poor kids...

nojoco

Sounds good with hanging the 815 speakers. There will be some high-frequency cancellations on the dance floor due to the direction the speakers will be used. However, it may not matter when the dance floor fills up! One speaker per channel on the 4000 amps would be a good setup.

The SRX828S subs (like most subs) do well the closer to the floor they are. The floor provides low-freq. coupling to occur, which usually results in much better lower-freq. response (without having to do "additive EQ"). However, if floor space is a concern, stacking them (like you referenced) will work well. Though, when stacking speakers, make sure they are strapped together... they will separate due to vibrations. The XTI 6000 amps will produce 2K watts @4-ohms. The 828S cabinets are 4-ohm, therefore, you will probably want to watch the power output of the 6000 amps when driving the SRX subs under EDM music. The SRX subs can handle 1200 watts continuously... this is less than what the 6000 amp can produce; you may want dial the 6000 amp down a couple of db.

Even though you are doing EDM, you will probably want to set a high-pass filter on the subs to protect them from potential over-excursion (especially in the sub-freq. range).

And yes... bi-amping will open up the clarity of the sound!

rickcollette

Again - thank you so much. I am learning a lot.
So - if i understand - the drivers in the 828 are each 8ohm, however because of the way they are wired in the cab, they end up being 4ohm.

So I want to send a 4ohm signal to the 828s? if so, then i have some 4000's i can use at 1200w 4ohms - i think.

I also have these whirlwind breakout boxes. I have one 14444 and one 14442 (http://whirlwindusa.com/catalog/black-boxes-effects-and-dis/splitters-boxes/sbnl-series-nl-splitter-breakouts)
Are these of any use to me?

nojoco

There's a lot to know with amplification and speakers!
You are correct, the 828 sub raw speakers are wired internally (in parallel) to produce a 4-ohm load for the amplifier. An amplifier will not send ohms to a speaker... it sends power to the speaker based on the ohms (resistance) of the speaker. This is why you may see more output power for an amplifier based on the lower (resistance) ohms the speaker has.
The breakout boxes may work for you at a later time... for now, I don't think you actually need those.

rickcollette

So - I think I'll do the 4000/4002's like this:

For dance/club nights:
4 of the 815's using 2 of the 4000's stereo 8ohm 650w/channel
4 of the subs using 2 of the 4000's at 1200w per channel and 4ohm

For live band nights:
same setup with the subs
725/835's on the remaining 2 4000's for use only when there are live bands and the 815's would cause feedback issues.

I have a soundcraft board with separate outputs that I can use to control the speakers that get audio;
So run the DJ mixer into a channel pair on the soundcraft board, run the live sound into their own channels on the board, output for DJ or background music to 815's and subs, output for live bands to the 725/835 pairs and the subs.

I think this would work.

nojoco

Looks like a good setup; you have the right amps matched for the speaker loads. One thing to know about feedback; it is not caused by speakers. Feedback occurs due to improper mic placement (when the mic is usually to close, or directly out front of the speaker) or improper gain setting on the channel the mic is using (the gain is set way too high). All speakers will "feedback" if either of those conditions exists. Make sure the gain is set good for the mic (not too "hot") and keep the mic out of the way of the speaker.