Powered Subs: 18" or 15"?
Behringer B1800-D
Behringer B1500-D
Bottom line: the 18" is $85 more, 27 lbs heavier, and rated 1 dB louder. Is it worth it to go 18 or 15?
For all kinds of events, adult parties to college parties to youth events.
id buy the 18, but thats because i have 2 B215d (15" active monitors) and a 15" sub just wouldnt cut it.
are those GC prices?
No, they are from Amazon. GC will match the price of the 18" but with tax it doesn’t make it worth it.
you should probably take a look a the frequency range and see what meets your needs.
both are rated at 20 to 200Hz (-10dB)
Sounds like not very accurate specs which is pretty typical.
Which Speaker Do I Need?
As you have probably noticed, we make these subwoofers in two different woofer sizes. Which one is right for you? An 18" woofer has more surface area with which to move air than a 15". If you’re engineering sound for a small jazz combo in a small club, the B1500D-PRO might be all the speaker you need. If you need to provide pounding techno sounds to a standing room only nightclub, the B1800D-PRO might be the better choice.
I saw that on the behringer website, but it doesn’t provide any evidence as to why. If the specs are all the same (accoridng to Behringer…except for 1 dB and added weight), is the 18" just going to move more air?
Yes. Moving more air is exactly what you want your sub to do. Looking at the numbers only gives you part of the story, head over to GC and listen to those subs next to each other to hear the rest. 
The sub will hit harder and feel deeper the more air it pushes around. It’s something that that stats can’t describe but you can totally feel when the sub is in front of you.
Imho you’re gonna want the 18".
I know money is an issue.. it always is… but if at all possible - try to stay away from Behringer loudspeakers. For starters the sound quality is awful and their specs are exaggerated.. 2. build quality is just as awful as the sound quality which means that over the course of a couple of years you’ll wind up spending as much as you would have to purchase a good quality sub… I’d recommend looking into the QSC line of direct radiating powered subs… They are going to be twice the price of what your looking at, but they sound much better and will last much longer.
thanks jake, I’m going to get the 18…unfortunately GC doesnt stock the 15, but I’l take your word.