CECAA850 Posted January 8, 2014 Share Posted January 8, 2014 How big does the manifold need to be? In a perfect world the opening to the IB would have the same area as the sum of all the surface area of the drivers. Most can't manage that so go as big as you can. Let's see, an 18" driver's area is 3.14x 9 squared. That's about 254"/driver or 1017 square inches for the opening or roughly 32" x 32". Smaller won't hurt, get what you can. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted January 8, 2014 Share Posted January 8, 2014 Be sure to double check my math, sometimes I don't carry the 1................................................ Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted January 8, 2014 Share Posted January 8, 2014 No chance I am getting 4 now, but hope to build the manifold for 4 and add as I can. Perfect. Prepare the holes complete with threaded inserts and build blanks to fill them. Get the EP-4000 now and you won't need to upgrade later. If you buy dual 2 Ohm drivers, you can wire for a 4 Ohm load per channel now and 2 Ohm after you get the next 2 drivers. Quote Link to comment Share on other sites More sharing options...
WakeJunkie Posted January 8, 2014 Author Share Posted January 8, 2014 Looks like the EPX4000 is $20 more but has RCA inputs. Anybody have negative to say about this one? http://www.musiciansfriend.com/pro-audio/behringer-europower-epx4000-power-amp?pfm=sp Changing the fan wouldn't be a problem. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted January 8, 2014 Share Posted January 8, 2014 (edited) Anybody have negative to say about this one? I'd be surprised if anyone did. They've been building this amp for years which is basically a cloned QSC. Even if you were one of the rare people to have an issue, there's plenty of warranty on them. They're also one of the few amps in this price range that actually put out their rated wattage. Mine has been wired for a 2 Ohm load for the last 7+ years without the first issue. HT duty isn't really that hard on a pro style amp. If you get one, pay careful attention to the dip switches on back. You might accidentally engage a 50 of 30 Hz filter and lose all your bottom end! Ask me how I know, LOL. EDIT, I misread and thought you were talking about the EP-4000, my bad. Edited January 8, 2014 by CECAA850 Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted January 8, 2014 Share Posted January 8, 2014 (edited) but has RCA inputs The EP-4000 should have RCA's as well. My mistake, it has 1/4" and XLR. I used a 1/4" to RCA adapter on mine. Edited January 8, 2014 by CECAA850 Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted January 8, 2014 Share Posted January 8, 2014 Like this. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted January 8, 2014 Share Posted January 8, 2014 Looks like the EPX4000 is $20 more but has RCA inputs. Anybody have negative to say about this one? http://www.musiciansfriend.com/pro-audio/behringer-europower-epx4000-power-amp?pfm=sp Changing the fan wouldn't be a problem. Be sure you can find independent testing that shows output below 20 Hz. Some amps roll off there fairly sharply. If so, it would be easier on your back then the EP-4000! Quote Link to comment Share on other sites More sharing options...
BE36 Posted January 9, 2014 Share Posted January 9, 2014 (edited) Four 18" drivers and amp is getting close to costing as much as a used Velodyne DD15. . . http://www.ebay.com/itm/Velodyne-DD-15-Powered-Subwoofer-/171212669738?pt=Speakers_Subwoofers&hash=item27dd12032a Goes down to 9 Hz, 15Hz is -3dB. My Velodyne SPL-15, not as good or low as the DD, on a cement floor in the basement shakes the whole house including the second story, just ask my children that sleep on the second floor. Feel bass in my chest and rear end (couch shakes). Auto calibration to room works great. I do not know any thing about IB subs - Have only owned sealed Velodynes. Would love to Audition Tapered Horns and IB. From what I have read and your skills I thought you might build a Tapered Horn for fun of it and cost / output advantages. Maybe you could build both Tapered and IB and sell one or tune one for music and the other for movies? I may try dual 30 Hz Tapered horns in couple of years, they fit my space and hopefully be more geared towards music while still being acceptable for HT. Given the size of your room location of the sub(s), firing direction and having multiple subs may be just as important as sub type. Edited January 9, 2014 by BE36 1 Quote Link to comment Share on other sites More sharing options...
fuzzydog Posted January 9, 2014 Share Posted January 9, 2014 Anybody have negative to say about this one? Ask me how I know, LOL. How do you know? Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted January 9, 2014 Share Posted January 9, 2014 Anybody have negative to say about this one? Ask me how I know, LOL. How do you know? I know what I know what I know. That's how I know, you know? Quote Link to comment Share on other sites More sharing options...
WakeJunkie Posted January 9, 2014 Author Share Posted January 9, 2014 Four 18" drivers and amp is getting close to costing as much as a used Velodyne DD15. . . http://www.ebay.com/itm/Velodyne-DD-15-Powered-Subwoofer-/171212669738?pt=Speakers_Subwoofers&hash=item27dd12032a 4 -18's or a single 15 and the 15 cost more....that's a hard sell. I can build anything. That's not a problem. Quote Link to comment Share on other sites More sharing options...
Moderators Youthman Posted January 9, 2014 Moderators Share Posted January 9, 2014 Four 18" drivers and amp is getting close to costing as much as a used Velodyne DD15. . . http://www.ebay.com/itm/Velodyne-DD-15-Powered-Subwoofer-/171212669738?pt=Speakers_Subwoofers&hash=item27dd12032a 4 -18's or a single 15 and the 15 cost more....that's a hard sell. I can build anything. That's not a problem. I agree. I have owned several Velodyne subs including dual HGS15's and although they are impressive, I can't imagine a single Velodyne 15" being able to compete with (4) 18" drivers. That's just mere physics. Quote Link to comment Share on other sites More sharing options...
BE36 Posted January 9, 2014 Share Posted January 9, 2014 Four 18" drivers and amp is getting close to costing as much as a used Velodyne DD15. . .http://www.ebay.com/itm/Velodyne-DD-15-Powered-Subwoofer-/171212669738?pt=Speakers_Subwoofers&hash=item27dd12032a4 -18's or a single 15 and the 15 cost more....that's a hard sell.I can build anything. That's not a problem. Aim positive you can build it, costs are getting close. 1 Quote Link to comment Share on other sites More sharing options...
Moderators Youthman Posted January 9, 2014 Moderators Share Posted January 9, 2014 Cost is getting close but I'm not following the logic. I would understand if one DD15 was equal to the (4) 18's he is considering. My guess is 1-2 of those 18's would best the velodyne 1 Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted January 9, 2014 Share Posted January 9, 2014 My guess is 1-2 of those 18's would best the velodyne In an IB??? I'm not so sure. 4 yes. in every category. Quote Link to comment Share on other sites More sharing options...
WakeJunkie Posted January 9, 2014 Author Share Posted January 9, 2014 (edited) My guess is 1-2 of those 18's would best the velodyne In an IB??? I'm not so sure. 4 yes. in every category. I have found very little info on an IB with only 2 18" drivers. (There is probably a good reason) Maybe you can help quantify this. Any chance you could turn off some subs for a test and see what kind of levels you get with just two 18" subs. Doesn't have to be elaborate, but if you can hit 100dB at 15Hz is a big difference than 90dB etc. If you have the time, it would be greatly appreciated to many I am sure. Thanks for all the help so far. Edited January 9, 2014 by WakeJunkie Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted January 9, 2014 Share Posted January 9, 2014 I'm not sure that's a good way to check. The unpowered drivers would act as passive radiators at that point. Not quite sure what that would do to the results. Let me snoop around the Cult and see if I can dig anything up. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted January 9, 2014 Share Posted January 9, 2014 For reference, I sit 14' away from the drivers. The most I thought my house could stand was 110dB @ 10Hz. The measurements were taken at the seated position using the correction table for the Radio Shack meters. Cutting that in half would be around 100 dB@ 10 Hz, roughly 110 dB @ 20 Hz. I'm sure someone could figure out just how loud that is at the drivers but it was crazy in the house. Any doors that were shut were shaking like someone was trying to get in. The windows in the back of the house were bowing visibly, the ceiling fans in the adjacent room were actually turning slowly and that's with the drivers I have. Yours will displace about a liter more (for the set) and have about 3mm more Xmax. 1 Quote Link to comment Share on other sites More sharing options...
Moderators Youthman Posted January 9, 2014 Moderators Share Posted January 9, 2014 Wake, I'm not sure if that will be enough for you. If you are going to upgrade your subs, I want to see some structural damage. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.