Advice on New Setup :D

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Originally Posted by pier

Anyone that knows a bit of acoustics will tell you the contrary. Having a sub near a wall is the fastest way to muddy bass and phase interference problems.

In an ideal situation your listening space would have no walls to avoid constructive / destructive interferences.

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I disagree. Having subs in the death zone, Ie, more than half a wavelength, or less than 2 wavelengths from a wall is an instant formula for extreme lack in bass, due to the above mentioned phase interference problems. This is the main cause of the power alley efffect.

Bass Frequencies are omni directional, so, putting the sub close to the wall can gain you as much as 3-6 dbs of volume, and cut down on phase issues.

n quick play around with http://www.falstad.com/wave2d that applet will help.

In short, Unless you have a way to suspend a sub, in a 100x100x100 foot room, in the center...... Then it really is important to *properly* place them, near walls, Because improperly placed subs, or subs that have been split by less than a wavelength, but more than 1/2 a common bass wavelength (bassically more than 6-10 feet, even though 35 hz is like 22 feet or something) will cause MAJOR phase issues, and you might as wel have half as many subs as you actually do

If I had 2 grand to spend on speakers I would def go witn JBLs but I would get a djm800 mixer before i would get speakers

JBL and EV used to be the same company I believe, before altec lansing split up.

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Originally Posted by sine143

Bass Frequencies are omni directional, so, putting the sub close to the wall can gain you as much as 3-6 dbs of volume, and cut down on phase issues.

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Of course you will gain some DBs at some frequencies, but you will loose some DBs in other frequencies. If that is good or even desirable to you...

Also, having a sub is a bad idea unless you have a proper treated acoustic space, a very open space, or have no hearing criteria and just want some punch bass no matter what.

No SUB?? lol now im confused about something else. its okay though. I'm still doing my research, but everyone helped out a lot with the initial info.

Ill tell you how it turns out!

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Originally Posted by pier

Of course you will gain some DBs at some frequencies, but you will loose some DBs in other frequencies. If that is good or even desirable to you...

Also, having a sub is a bad idea unless you have a proper treated acoustic space, a very open space, or have no hearing criteria and just want some punch bass no matter what.

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If you are crossing over below 100 hz, hipassing above 35, and running RTA, wall loading is definitely beneficial Especially if you are using horn loaded subwoofers, as wall/corner loading servest increase horn length. I'm sticking with it.

I'm just trying to keep him from seperating 2 subs, and getting low output due to horrible phasing. Thats never fun, and it can kind of ruin the vibe.

Few clubs are "acoustically" treated areas. Granted, most clubs have shitty sound, but thats not really the point.

I

Why would you want to do anything with your subs other than stick them in a corner or against a wall? You're getting free gain because the wall acts as a horn.

I think the problem here is the clarification between studio monitoring and live sound. Studio monitoring, using a sub is a bad idea because your mixdowns will end up being very lacking in the low end. In live sound, stacking subs and loading is the only way to go.

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I think the problem here is the clarification between studio monitoring and live sound. Studio monitoring, using a sub is a bad idea because your mixdowns will end up being very lacking in the low end. In live sound, stacking subs and loading is the only way to go.

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Ohhhhh. gotcha.

Update: I ended up getting:
2 x Harbinger HX121 12''
2 x Harbinger HX 118 18'' subs
2 x QSC GX5 amps
w/ cables and stands and what not... for about 2,000. Just got today so I'll keep you guys posted on how it goes with my gig tomorrow.

You probably could have driven all of that on 1 amp.

Flip the crossover switch on the amp. run a cable from channel 1 to your first sub, nother cable from that sub to your second sub (this drops the impedance from 8 ohms to 4, meaning the subs will see about 750 watts from the qsc: 300-325 to each sub). In all honesty, you wont notice much of a difference between driving those subs with 500 watts or 300 watts, maybe 1-2 db, because of the enormous amount of power it takes to increase volume at high levels
Granted, 2 amps will give you a lot more headroom and flexibility in your setup.

Good luck with your gig. I hope it goes well! remember to keep the subs close together (even if pier and I argued about the wall thing). it would be best to run the amp in xover mode anyways, cause you dont want to feed lows to your tops, and highs to your subs/vice versa.