BillFitzmaurice.info

DJ Higgumz wrote:Good idea!

Not trying to rain on your parade, but I think you need to think this through. You said the "corners of the track", I assume that you mean a track around a football field. Not only will you need several hundred feet of speaker cable to reach all the speakers - you will have to double that if you run bi-amped...not to mention more amplifiers.

And bottom line you aren't really gaining anything. The difference between a 90 degree dispersion and a 120 degree dispersion is moot after 20 or 30 feet. Most people will be much further away than that. And anyway, it's not like once you get outside the speaker's dispersion it goes silent - it just doesn't have quite the clarity or high end....but, people will be able to understand the spoken word fine and they will know that music it there. And typically, they are walking - so they won't be out of the sweet spot for long.

Don't get tunnel-vision here....look at the big picture.

I was planning on spreading them 100 ft to each side. who knows maybe by the time I will be able to build the Drs and everyone will be happy!

Apologies DJ Higgums,
I didn't realise you wanted to spread your cabs quite that wide!
That makes it much less workable.

Bruce is quite right, the wide dispersion benefit is only out to around 30 feet.
You could still do the prebuild DR arrays and place them on top of the SP2's as centrefill, with the (as you're looking at the stage/setup area) left arrays right edge and the right arrays left edge side to side, giving you 240 degrees dispersion up close and beaming left and right beyond 30 feet, with your dual 6's beaming straight forward. That would give greatest coverage all up. Yes, you'd need another amp as well, but it would cut way down on cable runs etc.

You shouldn't run your speaker cable more for than 45 feet ish runs, so if you insisted on doing what you have in mind, you would need to run power and a signal lead for the distance you require, which would hook up to a crossover and amp each side. Not good...

Grant Bunter wrote: You shouldn't run your speaker cable more for than 45 feet ish runs, so if you insisted on doing what you have in mind, you would need to run power and a signal lead for the distance you require, which would hook up to a crossover and amp each side. Not good...

I often see advice like this, and I have to strongly disagree. I routinely run speaker cables of 100-125' with no ill effects. In fact, two of my FOH cables are well over 100' to reach from one side of the stage to the other for over half the events I do.

125' of 13 gauge wire with a 4 ohm load nets a 1db loss, which is inaudible. 250' is 2db, which is just barely audible. Going to 12 or 14 guage wire changes it fractions of a decibel. An 8 ohm load cuts the loss in half (of course, two ohms doubles the loss).

While you can lose some HF on long runs, it's nothing that can't be fixed with a bit of EQ (if you can even hear it at all).

Long runs are par for the course in installations as well. In big auditoriums, there's usually no way you're getting the amps even within 100-200 ft of the mains. We're working at a swimming pool right now where the shortest way to get to the farthest speaker is 250ft. The solution for instances like these is to go to 12 gauge wire (10 if necessary) and oversize the amp a bit. It works just fine.

Sometimes I think we get blinded by what is "technically" best whilst forgetting that our ears can only discern moderate differences in sound.

BrentEvans wrote: I routinely run speaker cables of 100-125' with no ill effects.

I agree with this, but my point was - should he invest in a bunch of speaker cable x 2 (if he biamps) for no discernible improvement in sound quality for a one-time event?

He'd be better off doing this event with what he has, positioned as far as his cables will allow and call it a day. Use the money saved to build more cabs.

Having participated in many of these over the years - I've found that those who really care about the announcements will come to the speakers, but most are just there to walk and support the cause.