masterxela Posted July 24, 2007 Author Share Posted July 24, 2007 Haven't bought it yet, problem is, with 4 8ohm drivers, I can only do 2 or 8 ohms. No pro amps run at 2 ohms bridged. Crown xti 1000 or 2000 is next choice. Just a lot of money for $315 in drivers. Usually in this situation I just run the amp in parallel (not bridged), which yields 4 ohms on each channel. With the xti 2000, what's the difference between putting 4 ohms on each channel, or just bridgeing it at 8ohms? Quote Link to comment Share on other sites More sharing options...
DrWho Posted July 24, 2007 Share Posted July 24, 2007 Haven't bought it yet, problem is, with 4 8ohm drivers, I can only do 2 or 8 ohms. No pro amps run at 2 ohms bridged. Crown xti 1000 or 2000 is next choice. Just a lot of money for $315 in drivers. Usually in this situation I just run the amp in parallel (not bridged), which yields 4 ohms on each channel. With the xti 2000, what's the difference between putting 4 ohms on each channel, or just bridgeing it at 8ohms? About 6dB of distortion Quote Link to comment Share on other sites More sharing options...
DrWho Posted July 24, 2007 Share Posted July 24, 2007 Oh, and I've seen and listened to high excursion drivers, tcsounds, adire audio, and I don't really care for the mechanical noise from the spider etc when excursion gets anymore than an inch, not that I'd turn it down though... Is it mechanical noise or intermodulation distortion? Probably a combo of both, but I'd wager that they are pretty quiet if you pull them out of the cabinet and run them to full excursion in free air...or at least I'd hope they'd be quiet (which indicates that mechanical noise is low). Quote Link to comment Share on other sites More sharing options...
masterxela Posted July 24, 2007 Author Share Posted July 24, 2007 Oh, and I've seen and listened to high excursion drivers, tcsounds, adire audio, and I don't really care for the mechanical noise from the spider etc when excursion gets anymore than an inch, not that I'd turn it down though... Is it mechanical noise or intermodulation distortion? Probably a combo of both, but I'd wager that they are pretty quiet if you pull them out of the cabinet and run them to full excursion in free air...or at least I'd hope they'd be quiet (which indicates that mechanical noise is low). probably so Quote Link to comment Share on other sites More sharing options...
michael hurd Posted July 25, 2007 Share Posted July 25, 2007 Having run the TC 3000 15 inch and the LMS 5400 18" free-air, I can most definately say there is nil for mechanical noise. Do not plug the rear pole vent when testing free air, you will have noise out the wazoo. I had to move the driver onto it's side and then there was no noise. Quote Link to comment Share on other sites More sharing options...
masterxela Posted July 26, 2007 Author Share Posted July 26, 2007 These things are already wicked rigid. I'd do more bracing, but it's going to be hard for 2 guys to take 'em down stairs Quote Link to comment Share on other sites More sharing options...
michael hurd Posted July 26, 2007 Share Posted July 26, 2007 Poor dog is not going to know what to do... hehehhe.... Looking good! No replacement for displacement! Also going with multiple drivers of lower xmax yields a lot of benefits ( less heating of voice coils ) and so on. Awesome! Quote Link to comment Share on other sites More sharing options...
masterxela Posted July 26, 2007 Author Share Posted July 26, 2007 keep running into obstacles... jigsaw broke, need rca to xlr adapters for the crown... some progress though Quote Link to comment Share on other sites More sharing options...
darkside Posted July 28, 2007 Share Posted July 28, 2007 When you say for your room do you mean that you live with your parents? Isn't 4 18's kind of pointless in that situation? I guess I'd allow my son to own something like that but never allow him to utilize them in the way they were meant! Unless he wanted to donate them to the family home theater [] Actually my dad allowed me to have an Earthquake Supernova MK-IV 10 in my room (11' 6"x11'6"x8ft), but I have since gotten rid of my old stereo, bought some Madison PA speakers and donated the Supernova to the family HT, without my dad knowing [] Also, the boxes look good...I'll have to try your method of construction on my next box.....build a frame and panel it, I've never seen that, but I like it. Quote Link to comment Share on other sites More sharing options...
masterxela Posted July 29, 2007 Author Share Posted July 29, 2007 as far as my method of construction goes, be careful. If the outside pieces are cut precisely, mine were, and the final dimensions of the internal bracing are off by any 32nd of an inch, itll show up as either a gap or a "not fit" when you try to lay all the exteriors on. Power planar made it a 30 second fix, but without it, I would have been sanding for a long time. Quote Link to comment Share on other sites More sharing options...
darkside Posted July 29, 2007 Share Posted July 29, 2007 Yeah, I always cut the panels and glue them together...however, because of my lack of a decent saw, There are always minute gaps that I end up sealing with hot glue, or hot melt as I've heard it called, which does the job just fine... Quote Link to comment Share on other sites More sharing options...
CAS Posted July 31, 2007 Share Posted July 31, 2007 the bracing can be mdf? MFD makes outstanding bracing Quote Link to comment Share on other sites More sharing options...
TheEAR Posted August 1, 2007 Share Posted August 1, 2007 the bracing can be mdf? MFD makes outstanding bracing Doh of course,MDF makes very good bracing...even better go with multi ply void free birch...my material of choice. Quality void free Baltic birch over MDF any day...and I have now built several subs using MDF and multiply birch. Brace brace,douible on the walls and triple on the baffles.Cannot beat that,tank like and no detectable vibrations or colorations. Wilson like in the cabinet departament. Quote Link to comment Share on other sites More sharing options...
CAS Posted August 2, 2007 Share Posted August 2, 2007 as far as my method of construction goes, be careful. If the outside pieces are cut precisely, mine were, and the final dimensions of the internal bracing are off by any 32nd of an inch, itll show up as either a gap or a "not fit" when you try to lay all the exteriors on. Power planar made it a 30 second fix, but without it, I would have been sanding for a long time. Just cut each free end an 8th to 16th too long and the router becomes the great equalizer! Praise be to Porter Cable! Quote Link to comment Share on other sites More sharing options...
darkside Posted August 2, 2007 Share Posted August 2, 2007 MDF is all I use for my boxes...MDF and glue, that's it. Although...if I remeber right, cabinet material makes negligible differences in sound, but I can see how a sub like Ear's dual TC-3000 would weigh close to 500 lbs made of 3/4 MDF.... Quote Link to comment Share on other sites More sharing options...
darkside Posted August 22, 2007 Share Posted August 22, 2007 Any update on the 4 18s? Quote Link to comment Share on other sites More sharing options...
masterxela Posted August 24, 2007 Author Share Posted August 24, 2007 Denon blew up, so I'm getting a new one tomorrow. New apartment has severe volume problems until I move everything downstairs. Once I'm set up and can finally do some measurements and tweaking, I'll have a big write up. Quote Link to comment Share on other sites More sharing options...
darkside Posted August 24, 2007 Share Posted August 24, 2007 Cool. Quote Link to comment Share on other sites More sharing options...
masterxela Posted September 11, 2007 Author Share Posted September 11, 2007 Everything is setup and sounding sweet. Major room issue is between 35 and 50hz, with a +20db peak at 40hz. What a coincidence that my room is 343/40 meters long.... (RS db meter, so who knows what the actual number is) Secondary issue, who guessed it, with the other parallel walls. +10db at 75hz. Room happens to be 343/75 meters wide. Its nice when math works Most recordings sound phenomenal. Any with sustained 40hz info is bothersome though. Only thing I listen to regularly that low is tool. Rf-7's on large with sub off dig sooo deep down here. Authority to 35hz. Unbelievable. I set the crossover at 40hz (don't tell me I'm wrong until you come down here and listen to music with the crossover at 60 or 80, because you can't, just take my word it does not sound as good) 35hz is deafening, 30, I'm starting lose definition and beginning to pass by the "super audible" band, moving into only feel. from 20hz down to 15hz, I can hear the door to my basement shaking on its hinges, at the correct frequency. It's cool, but I'll try to shut it up somehow. db meter said 96 at 15hz, not bad for a 3000 cubic foot room. Having solid concrete floor and walls is so nice after being in and hearing other "drywall" systems. The bass is so pure, no weird stuff, no floor vibrations, no wall flexing, no random noises. The absence of feeling the bass through transmission on the floor is the nicest. I feel the hair on my head move before my whole room is rattling like the trunk of a cadillac rollin' on 22's. Now the floor right above me is another story. Out of control up there, like I was kidnapped and put into that trunk. Standing up there feels like a foot massager thats low on batteries. If anyone knows what software I need and how to go about using my computer to use the eq on my crown xti2000, lemme know. Also, what mic should I buy to use rew, or an equivalent program and get good results down to 20hz ish. Further projects include, getting money to buy a less crappy projector, and bass traps. Quote Link to comment Share on other sites More sharing options...
michael hurd Posted September 11, 2007 Share Posted September 11, 2007 With a 20 hz sine wave, I can move the rear doors 1/4" p-p on my car... hehehe.... As far as a mic, Dr.Who is having good results with his Behringer ECM 8000, the same model I have purchased. Quote Link to comment Share on other sites More sharing options...
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