I was hoping to get a little help on our live sound. maybe someone could recomend another forum.

"I was told that I should get another power amp and an active crossover. Then use one amp for the mains and the other for the subs. How much of a difference would this make?"

I'm not a live sound guy but here is what I know (for what it's worth).

Yes, it WILL make a difference however; with that said, as you pointed out it's an expensive difference.
People will tell you "yes do it" but, it's NOT their money. A lot will depend on where you're playing, etc.
For 90% of the bars I've ever been in the drunks in the back could care less. What I would do is this.
Borrow or Rent a second power amp, crossovers, etc and at the next gig try it out. See if it is worth it to you.

Some people are all about live sound and some do enough to get by. Can you tell the difference? of course you can but again.. for that 100 bucks apiece gig is it really worth it.

If you keep this near the top, I imagine eds... will arrive at some point. He's a live sound guy, (as well as a studio head,) and probably has your answer. I'm more in line with duane here. Rent it, try it and then decide if you need to go there. Crossovers will certainly help the subs, and I've seen setups exactly the way you explained it. Unfortunately, I can't tell you if it will make that much difference. A lot will depend on the venues you play.

The only time I see a problem with our current set up is when we play outdoors and the 2 biker bars we play that want ridiculous volume. All the local bands around Charleston have gone the route of big subs and towering mains.

We are stuck between keeping up with the Jones or being left behind.

It seems like the new trend is a lot of bottom end.

Here I am!

This is a very interesting question. Basically it all boils down to "it depends". First of all, do your subs have built in passive crossovers? If so, you can get by doing what you are doing, providing you aren't going too low on your ohmage, possibly sending your amp into protect mode. Passive crossovers aren't very common in subs that aren't active - there's only a handful I can think of that do this.

If you don't have a passive crossover on your subs, well the answer swings right over to YES, it will sound way better. Get a crossover, crack the manual for your sub, and find out what the frequency should be set at. Your whole system will seem to "open up" with not only bass, but focused bass as opposed to a muddled sort of sound.

Ok, this brings us to a different topic. When you are running your mains, is your power amp higher in wattage per side that your speakers can handle? When you add the subs, it lowers your ohms and your power amp will dish out more power - providing it can handle the new lower ohm value. If you add the ratings of one main and one sub, is the total power handling less than your amplifier dishes out?

Basically you want speakers that can handle equal or more power than your amplifier can dish out. For example a 400 watt main shouldn't be getting 500 watts. However adding whatever you have on that leg of the amp, let's say a 400 watt main and a 1000 watt sub, shouldn't have an amp putting out more than 1400 watts.

If you have an active crossover I recomend throwing a compressor on the sub side with an attack of like 20-30 MS and a release of 10-ish to really kick out the bass.

The last point I have to make in favour of adding a crossover is this: Your mains won't have to do so much work running entirely full-range material, and your subs will be tighter only amplifying the bass - these efficiencies combined with the second amplifier will make your system louder and more than likely last longer.

One more important thing about amps - this is mainly why I try to match the wattage of the amp with the speakers I plan to use - it's easier/faster to blow a horn with an underpowered amp than an overpowered one. Why? Because you want to turn that smaller amp up louder, and when you clip an amp it really fries the tweeter FAST, whereas just giving it too much power may burn it out over a longer period.

Of course, if your system has a passive crossover and gets loud enough as well as sounds good, why would you want to change it?


My personal PA system is a combination of active and passive speakers, and is mainly Yorkville. I use an allen & heath mixwizard and a mackie 1402 VLZ for monitors [yes, I prefer having a seperate mixer for monitors].

4x performance series Y115
2 Elite Series EX401
2 Elite 190p
1 Yorkville EX 1
1 yorkville EX 2

I really recomend the EX-1 or 2 - -it's basically a cart with a subwoofer on it and the speakers mount on top and is brain dead to set up... 1 power cord, and 2 speakon cables. Loud. Here's a link.
http://www.yorkville.com/products.asp?id=270&cat=41&type=29

It's about time! ;p

Yeah, it's weird... I've had a life lately and have just been lurking in the background of guitar.com

Got the crossover and another power amp and what a difference. This is the live sound I have been looking for for more than 20 years

The power amp I got was a 1974 Pravey cs800. It is a tank. It takes uo 4 rack spaces and weighs 60 lbs. It was given to me so I cant complain.

Your speakers will love you, too. It's pretty rare to have a passive sub with a built in crossover. I can actually think of only one example.

If you know anyone whos giving out free power amps... I'm in the market for an installation I'm doing :P