mustang guy Posted April 27, 2015 Share Posted April 27, 2015 Four KW-120 subs should be enough bass for any room. Our member bhenry has 4 in an odd shaped HT room and 4 of these things. He says the bass is lacking. I am somewhat stunned since Michael Colter has said they are fantastic subs. Here are some pictures of this room: Your thoughts? 2 Quote Link to comment Share on other sites More sharing options...
OO1 Posted April 27, 2015 Share Posted April 27, 2015 I would think that (4) four 15 inch subs are required in the room - so adding two (2) 15 inch subs in the front of the room would be needed as a minimum if not (2 )18 inch subs - 1 Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted April 27, 2015 Share Posted April 27, 2015 (edited) If that room is a basement in my personal experience it may not be enough. I lost about 10 db. going from roughly the same size space upstairs when I moved the gear to the basement. That space also looks open in several areas which was another problem I ran into. Concrete cover with carpet will deliver less tactile response than being on a wood floor. Drop ceiling and some other construction basement ceilings can act as bass traps in a negative way. Symmetrically placed subs will reinforce the same dips and peaks in the FR. Also, that seating looks to be close to half way of the length of the room which is an area of poor bass. Some measurement would help before choosing which direction to go as a remedy. Edited April 27, 2015 by derrickdj1 3 Quote Link to comment Share on other sites More sharing options...
mxr dad Posted April 27, 2015 Share Posted April 27, 2015 I'm wondering how much may be lost going up those stairs. Can you hear strong bass at top of stairs? 1 Quote Link to comment Share on other sites More sharing options...
willland Posted April 27, 2015 Share Posted April 27, 2015 A big room indeed. Thick carpet, big fluffy cloth furniture, open passage ways, are a recipe for a bass draining environment. so adding two (2) 15 inch subs in the front of the room would be needed as a minimum Agree, or maybe in the rear of the room. Bill 2 Quote Link to comment Share on other sites More sharing options...
Chris A Posted April 27, 2015 Share Posted April 27, 2015 (edited) Your thoughts? Taking a REW sweep at the listening position(s) would help to isolate the frequencies of the room modes that are cancelling the LF. For instance, are those cancellations sharp or broad? What frequencies? You could also use the "Room Sim" visualizer in REW to put in the basic dimensions (width, height, length) of the front portion of the room to see if the locations of the subs are optimal or really suboptimal (the most likely issue that I see). You don't even need to run a sweep to do this - just install REW and plop in your room dimensions and move around the locations of the subs and the listening position to match the current positions, then move them around in Room SIm to see the effects on the FR. Chris Edited April 27, 2015 by Chris A 2 Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted April 27, 2015 Share Posted April 27, 2015 Taking a REW sweep at the listening position(s) would help to isolate the frequencies of the room modes that are cancelling the LF. For instance, are those cancellations sharp or broad? Cancellation was my first thought a s well. 2 Quote Link to comment Share on other sites More sharing options...
mustang guy Posted April 27, 2015 Author Share Posted April 27, 2015 Now all we need is for bhenry to come on the forum again. He was talking about building a back wall which would make the room much smaller and change the dynamics of the standing waves. 3 Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted April 27, 2015 Share Posted April 27, 2015 Now all we need is for bhenry to come on the forum again. He was talking about building a back wall which would make the room much smaller and change the dynamics of the standing waves. It would certainly do that. I've seen issues before when subs are placed either where they're aesthetically pleasing or where the room dictates as opposed to using acoustic placement. Just for grins, I'd shut off either the ones behind the couch or the ones in the wall and see if bass improves. 3 Quote Link to comment Share on other sites More sharing options...
mxr dad Posted April 27, 2015 Share Posted April 27, 2015 You think he could block it off with some poly (plastic) as a temporary so it wont be such a pain the arse? I would think the bass would reflect off the poly? Dunno Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted April 27, 2015 Share Posted April 27, 2015 You think he could block it off with some poly (plastic) as a temporary so it wont be such a pain the arse? I would think the bass would reflect off the poly? Dunno It would go through it like it wasn't there. 1 Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted April 27, 2015 Share Posted April 27, 2015 (edited) I put up some door and and walls: it helps. Now we are spending money and it is All ABOUT THAT BASS, lol. Edited April 27, 2015 by derrickdj1 Quote Link to comment Share on other sites More sharing options...
bhenry Posted April 28, 2015 Share Posted April 28, 2015 Thanks for the help, guys! Maybe I'm expecting too much, but I feel like the bass performance is lacking. I understand the stairway is an issue and the overall size of the room is also an issue. I am considering building a wall where the room separates in pictures #1 and #3. I would love some suggestions on what I could do as temp situation to get an idea of what to expect before actually building the wall. I think I am missing the tactile response that was mentioned before. I can't feel the floor or the furniture shake, but I'm also not hearing the deep notes that I know are there in the songs I'm listening to. Placement is a problem due to the Klipschorns taking up the corners, I've thought about going to back to RF-7's so I can get my front corners back for the subs. I think the other problem is my losing interest in dick!ing around with this. I've done pretty well with the audio hobby for years........why not call it quits while owning what I have always thought is the ultimate loudspeaker? 1 Quote Link to comment Share on other sites More sharing options...
bhenry Posted April 28, 2015 Share Posted April 28, 2015 I have tried it with just one set of subs running in each position and there is a significant reduction in bass, so when they're all running it is much better. Does anyone think that if I were to purchase the Tuba sub, would I use it with the current subs or replace them? As a side note, I'll bet 99% of the general population would be happy as pigs in poop with the performance of this system so I should probably just shut my pie hole and be happy with what I've got, huh? Quote Link to comment Share on other sites More sharing options...
bhenry Posted April 28, 2015 Share Posted April 28, 2015 Also, for the record it does sound pretty sweet with movies. Music is the problem. Quote Link to comment Share on other sites More sharing options...
mustang guy Posted April 28, 2015 Author Share Posted April 28, 2015 I am curious about what would happen if you tinkered with the settings on the pre-processor. I know those have settings for the center and mains separately. Is there a considerable difference between the 'Subwoofer Ultra' and 'Subwoofer Yes THX' for the mains and center speakers? In both cases you can set the speakers to full range, or as they put it 'Large'. The reason I bring this up is that there may be cancellation occurring between the fronts and the sub. In that case, it might be a timing or phase issue. The sub amps have phase controls which can eliminate these cancellations. You would set up the pre-processor with one channel of sub output and set the phase of that amp so it is loudest where you are sitting. Then turn on the second sub output and adjust the phase on that amp until it is loudest with everything on. It would be my opinion you would use the 'Subwoofer Ultra' / 'Large' settings for the KHorns, and the center 'Subwoofer Yes THX' / 'Small THX'. Then go through the phase adjustments. Quote Link to comment Share on other sites More sharing options...
mustang guy Posted April 28, 2015 Author Share Posted April 28, 2015 I have tried it with just one set of subs running in each position and there is a significant reduction in bass, so when they're all running it is much better. Does anyone think that if I were to purchase the Tuba sub, would I use it with the current subs or replace them? As a side note, I'll bet 99% of the general population would be happy as pigs in poop with the performance of this system so I should probably just shut my pie hole and be happy with what I've got, huh? HAHA, the fun is in the chase. Frankly, if you look at the output those subs you have are capable of, and that you are stacking them in two locations, I don't think you will beat it with tubas. A full size THT will give you about 119db max without corner loading and it is as big as all your subs put together. Just one pair of your THX's stacked will output 130db. Quote Link to comment Share on other sites More sharing options...
bhenry Posted April 28, 2015 Share Posted April 28, 2015 I have it set to Ultra. Have tried the mains set to large and to small, no major difference there. I know, these subs are supposed to be pretty sweet, let alone four of them! I'm thinking the room is the problem and I just don't have any interest in modifying it too much. I would build the wall if that made a huge difference, other than that I'm probably done chasing the perfect sound. Might have some pretty nice gear for sale soon. Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted April 28, 2015 Share Posted April 28, 2015 Room gain can be like adding a couple of more subs. The key is to shorten the length. How low is the room? Maybe even play some Real Traps test tone (free download) and see a crude FR graph. This will point things in the right direction on what should help. Quote Link to comment Share on other sites More sharing options...
Scrappydue Posted April 28, 2015 Share Posted April 28, 2015 ask user michaelandklipsch. he used to love his ultra 2 subs. he had 4 of them and i finally talked to him into some 18's. he bought the jtr S2. two of them but i bet he would tell you even a single one will best all 4 of them ultras. they are good subs but 12's have their limit ESPECIALLY in a basement. i loved my pb-13 ultra's when i had them. till they went to the basement. then i search for more. my 4 diy 18's are unreal compared to them svs ultra's 1 Quote Link to comment Share on other sites More sharing options...
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