Musician Gear & Tech Discussion

Ok, so after having such a great time at the gig Saturday. I have been researching ways to boost my sound system.
Our RX1200 is fine as is for small to medium sized venues especially indoors. ( I would like to add subs though) Our next to the last gig we played demonstrated to me that we dont push enough watts for a large outdoors area.
My Idea is this, continue to use my RX1200 PA indoors, outdoors just hook up the right and left signal outputs to a seperate set of amps and speakers, and use my PA / speakers as the mixer and personal monitors for the band. (like we did last Saturday)

So here's the question set up:
I can buy two subs, each that require 2000watts. Plus the two applicable amps.
Or, I can start with two 1000 watt subs, and one 2000watt amp to operate them.
Then latter on buy two more 1000watt subs and another amp.

The question : ( I know this will sound really dumb to some of you)

At the largest venue ( say a local highschool football field size or amphitheater)
Which will produce the larger volume of sound, or will the fact that it's 4000 watts total either way mean the difference in neglageble.
Also considering versatility in the system.

(A) two 2000 watt subs (too much for a small venue)
OR
(B) four 1000 watt subs (can use one or two of these at a small venue)

Thoughts or comments

99% of all double 18" sub's have a maximum SPL of around 136db

Lets just say the pair of double 18" 2000 watt subs have 108 db's at 1 watt/1 meter

and the

double 18" 1000 watt subs have 104 db at 1 watt/1 meter.

reguardless of the lower db's of the 1000 watt subs, they will still more than double the output volume because you are moving a massive 144 inches of air vice 72 inches.

When it comes to (subwoffers used for outdoor gigs) the more the better reguardless.

Out door gigs require twice as much power to achive 108 db because there are no walls to reinforce the back wave.

See now that was the kind of answer I was fishing for.
Thanks RG.
The double 18"s were rated at a max spl of 136.
Where as the singles were rated at a max spl of 124.
Much appreciate the input on the output.

Ok, so after having such a great time at the gig Saturday. I have been researching ways to boost my sound system.
Our RX1200 is fine as is for small to medium sized venues especially indoors. ( I would like to add subs though) Our next to the last gig we played demonstrated to me that we dont push enough watts for a large outdoors area.
My Idea is this, continue to use my RX1200 PA indoors, outdoors just hook up the right and left signal outputs to a seperate set of amps and speakers, and use my PA / speakers as the mixer and personal monitors for the band. (like we did last Saturday)

So here's the question set up:
I can buy two subs, each that require 2000watts. Plus the two applicable amps.
Or, I can start with two 1000 watt subs, and one 2000watt amp to operate them.
Then latter on buy two more 1000watt subs and another amp.

The question : ( I know this will sound really dumb to some of you)

At the largest venue ( say a local highschool football field size or amphitheater)
Which will produce the larger volume of sound, or will the fact that it's 4000 watts total either way mean the difference in neglageble.
Also considering versatility in the system.

(A) two 2000 watt subs (too much for a small venue)
OR
(B) four 1000 watt subs (can use one or two of these at a small venue)

Thoughts or comments

...I'm not exactly sure of the type of subs you're talking about but if they are single 18" or 15" types theres a very good chance that they cannot handle 2K of power (very few exceed the Eminence Kilomax @ 1250 "RMS" watts).

Anyway since there is only a small difference in volume going from 1000 to 2000 watts (3 dB) you should probably look and compare the sensitivity spec of the speakers.

Speakers are rated or measured using 1 watt of power at roughly 3 feet away (1 meter), the typical spec you'll be looking for when comparing one brand against another is something like this "99dB @ 1w/1m" -the higher the number the louder the speaker.

If one companies speaker is 3 dB louder then anothers then you only need half the amount of power to get the same volume.

If you're playing at an outdoor show I'd recommend folded horns for subs

Folded horns are usually 3-6 dB louder then conventional (bass reflex) subs and are meant to throw the low frequencies much further.

A single 18" folded horn will throw low frequencies farther outdoors then a standard double 18" (bass reflex) cabinet.

Folded horns are usually not used indoors since the lows don't really impact the audience till about 30 or more feet away, at indoor shows double 18" subs are usually perfect

A pair of simple Cerwin Vega EL-36 folded horns (single 18") are around $1400 for a pair, for indoor use Yamaha has a nice sounding double 18" cab that goes for around $1300 a pair

As far as amplification you really don't need huge amounts of power to drive either of those types of speakers;

QSC makes a simple amp (GX5) that puts out around 500 watts into 8 ohms and around 700 into 4 ohms (the double 18" cabs are 4 ohms) for about $400...

Behringer has their own medium sized amp (EP 4000) that puts out a little more then the QSC at around $350

Crown has their XLS-802D which is in the same wattage area as the other two for around $500

Of course you could always buy a used Crest 8001 on ebay for around $800 (and 3 times as heavy) but I'd say you'll be fine with any of those simple modern amps.

If you do buy an amplifier from Guitar Center its a good idea to get the extended warranty in case there is an issue


Remember -The amount of watts (power) a speaker handles has nothing to do with its loudness

When I do buy I will probably go with Carvin again.
I know some people like to badmouth their stuff, but I love my system and my amp.
I see no reason not to continue to build upon what is working so well for us. And they have some package deals I can get into for less than advertised via the sales and service guys I have been communicating with.

Thanks a lot for the input.

IMHO, you are better off with the 4 seperate subs. In a smaller venue you can use just 2 but when you play the larger outdoor gigs you can use all 4 so it just makes more sense. In sound you have what is called a coupling effect 1+1=more than 2 the different uses for subs are; free space the worst case scenario where you fly subs, half space= outdoor gigs where you only have a floor and no walls, 1\4 space= floor and 1 wall, 1/8 space = floor plus 2 walls (when you place your subs in a corner) each one of these scenarios increases the db level of your subs and you will need to turn up or down the level of your subs based on which scenario you are placing the subs in. In most cases you will be using 1/2 and 1/4 space. I hope this helps.

George How loud are you trying to be?

Our band we have a pair of Yamaha 118 subs. I power these with a QSC 1450 amp in the bridged mode. Our tops are Yamaha 215 which we push with a Yamaha 7000 series amp.

We are using one of those DBX Rack Packs or hwatever you call it for our eq. I ussually run the sub amp at 75% power and the top amp at 60%, seems to balance it out better. If I could redo our setup I would have a 218 sub and a 115 top.

As far as the DBX, we had a strange thing happen at our last outdoor gig. We RTAed the system with pink noise and it locked in. When we ran it later the subs sounded like they were clipping the amp, which they were. We turned the sub amp down and finished the show. Yesterday I pulled the mains out and set them up. We had saved the program and when I looked at the graphic curve for some reason 2 of the lower bands were maxed out, causeing the amp to clip. I reran it and its fine.

Haley I think you use on of these units have you ever had it do anything like this? We ran the program and it eqed the area but Im wondering if the unit hadnt finished or maybe being outside we had the RTA mic in a bad position and it was overcompensating the low end for some reason. Thats the first glich weve run into with the DBX unit. In the future I will pay more attention to the curve we use and make sure its done its job before I lock and store it.

Yes Jw, any time you auto e.q. always go back to the eq display and check to see how it has set your e.q. when it sends out the pink noise and measures the room acoustics it willl automatically set it to what the room measures out at. The only problem with that is it may not be what your system can handle. JW, if you remember a while back I wrote about this. When you pull up the display in your driverack if you notice any boost over about 4 to 6 db higher than the rest of the spectrum, be they high or low you are going to want to get into the parameters and back those down they are not good for your speakers and are usually inaudible to the human ear anyways. They basically cause your system to work to hard to achieve a sound that is not even necessary.
That is the only problem with these systems I have seen. When you ask them to auto eq they do just that on the other hand if you notice drastic cuts in the eq spectrum you are going to want to raise those a bit as well. Those DBX Driverack P.A. are the best thing going in my opinion for small bands that do theyir own sound it would cost thousands of dollars to buy individual units that will do the same thing as the driverack pa they are a total front of house sound management system they make several versions. They even make one for powered speakered systems. You just have to get past the learning curve that you are going to face but once you know how to use that little piece of gear you will wonder how you survived all these years without it.

George, if I were you I would get the 2 subs and you are going to want power amps that provide at least 2 to 3 times the power your speakers are rated for and get one of these DBX Driveracks they are $499.00 and the RTA mike is an addional $99.00 but this is well worth the money and worry about getting the other two subs later. I have found that running 2 15's with horns and 4 - 18" subs is a sound for rock that can't be beat. I use a power amp bridged for each speaker. One other thing about using multiple speakers of any kind is you have to watch that they are not out of phase with each other or they will canel each other out and you will not get the results that you have spent the money to get. Just remember George sometimes it is better to just bite the bullet and get the best now otherwise you will be spending more money later. Get subs that are rated for at least 600 watts (for Single 18"s) I have QSC 1450's bridged running to each sub and let me tell you it will blow your hair back if you are in the audiance.

When I do buy I will probably go with Carvin again.
I know some people like to badmouth their stuff, but I love my system and my amp.
I see no reason not to continue to build upon what is working so well for us. And they have some package deals I can get into for less than advertised via the sales and service guys I have been communicating with.

Thanks a lot for the input.

Agreed, Carvin makes some excellent equipment

-All of their PA speakers use upper end Eminence raw frame drivers in plywood cabinets instead of those cheap crappy mdf cabs that many companies use for their low end stuff
-Their power amps are well built and an excellent value for the money
-Thier package deals are not only a good value but perform as expected

....if you think about it a mail order "only" company cannot survive unless they produce a decent product and Carvins been around for quite a while

In our band we use the BX1200 bass amp (upper bass/mids for the bass guitarists bi-amped rig) -sounds incredible with many tonal variations and tons of power

The DCM 1000 power amp to drive each of our guitarists 4x12 cabs with up to 350 real watts if needed

Two of Carvins NE18-8 18" (Eminence) sub woofers for each of the bassists single 18" monitor cabs -very efficient and lightweight

We will probably soon be purchasing Carvins new XD-88 digital eq -with eight individual 30 band eq's (one at each input) and eight 4 band parametric eq's (one on each of the 8 outputs) we can replace all of our older eq's with a single two rack space unit.

Thanks for the info. I will have to do some research ya'll lost me on the driverrack business. Then I had a crappy day and my mind is pooped.

John, it's not so much trying to be overly loud, I have been listening to you guys and working on having good sound at a good volume.
Must be doing something right, people keep telling me we have the best mix, when we play along side other acts.
( I am still high from last Saturday LOL)
Our greatist opportunities are working out to be outdoors in some rather large parks and ampitheaters. My current system wont carry a space like that.
Perhaps I am looking at overkill for now, but my intent is to play to thousands.
And my will is as strong as my faith.

George Ive always like to over power rooms, that way you can cut it back and be clean and dont have all the feedback issues. We set our system up in my drive one time and measured the volume level at around 20 ft and were carrying 128 decibels. We never run our system like this in real life.

I would imagine we only run our system at 40-50% most of the time. Out doors recently we ran it at around 65%. The only problem with having excess power and paper is that if you arent careful you will get too loud sometimes. We did clear a room out one night when someone said turn it up and play that heavy sh*t, we did and we did. Finally some of the gals that come and like to dance said could you turn it down and play something that we can dance too. We did and they did.

I dont know your audience, if you are playing for familys and whatnot I would think you would want to keep it under control. Of course Ive seen bands with almost nothing for equipment that just sounded clear and great while Ive seen band swith huge systems that just sounded horrible.

Good Luck and keep us up on what you guys are doing.

Its about time to get on the road for tonights gig.

Just out of curiousity, does no one use powered subs?

I have looked at them. But I think it may be a lot like a powered board ya know. something goes wrong your screwed.
Want to have a back up system for everything .............. eventually.

For subs, we use powered JBL's. Only 500 watts, I think, but they have done the trick both inside & out for all our needs. Inside we only use one, outside we use both.