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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => SR Forum Archives => LAB Subwoofer FUD Forum Archive => Topic started by: JoshRice on October 13, 2004, 07:51:07 pm

Title: Need to build 2 single 18inch subs, Ideas?
Post by: JoshRice on October 13, 2004, 07:51:07 pm
hey guys, I need to build 2 single 18 inch subs or 2 2x18 inch subs.  Power will be off of a crest ca12.

I currently have a pair of community csx40 subs and not too happy with them.  Use them for all kinds of music both indoors and outdoors.  help.  Tops are 4 Community csx57's I would be willing to purchase one more amp for this project but have a budget for the amp of $500.  Not much I know.  I would like to build the cabs with decent quality.  Does not need to be the best,  but on a budget, a good sub.  

I am interested in using speakers from Parts Express as I am a wholesale member.  
Title: Re: Need to build 2 single 18inch subs, Ideas?
Post by: Peter Sylvester on October 14, 2004, 05:04:43 pm
If you click on the "Project Ideas" link under any driver on partsexpress.com they provide a reasonable reflex design for the driver.

--Peter
Title: Re: Need to build 2 single 18inch subs, Ideas?
Post by: Tim Padrick on October 14, 2004, 11:11:50 pm
First try to get the most out of the subs you have.

Power them properly - Amp continuous rating = at least 2x speaker continuous rating.

Place them together instead of with the tops.  They are more efficient, and you'll get smoother coverage throughout the venue.

Make sure that they are either within 2' of all room boundaries (floor, wall, ceiling) or at least 8' from boundaries.  If not, you get "holes" in the frequency spectrum.

Get a DSP crossover and delay the tops to the subs.  My system is all front loaded.  I have to delay the tops 12.5' (about 11ms I think) to get them to line up.  The system has a LOT more balls when the tops are properly delayed.


I'd just buy a QW218.  By the time you buy the drivers, good plywood, and all the hardware (handles, corners, grill, etc.) you are not going to save all that much, you may not get the same performance (unless you copy the box exactly), and you'll have "homemade" subs that will have no resale value.

http://www.padrick.net/LiveSound/SubwooferInfo.htm
Title: Re: Need to build 2 single 18inch subs, Ideas?
Post by: Marjan Milosevic on October 15, 2004, 11:40:27 am
Maybe that I don`t follow you well, but... what is delay doing in all front loaded box system Rolling Eyes ??????????