Room needs more bass

[mxr dad]

Have tried the mains set to large and to small, no major difference there.

 

 

This seems odd. I know when I change mine from small to large I notice a huge difference. 

[derrickdj1]

Rooms are 50% of the equation for good bass in a room and rooms have a set number of modes.  The question I ask myself is how good can I get things in this room.  Due to the modes, certain things may not be possible without a total overhaul of a room.  The size/shape of a room will have a constant number of mode.  You can change the distribution of some of the modes over 100-200 Hz but, the ones under 100 Hz are dominant and very little can be done with them unless the room under goes radical changes. 

Edited April 28, 2015 by derrickdj1

[edzu1234]

PLACEMENT!  PLACEMENT!!  PLACEMENT!!!    

[garyrc]

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. ...

 

.......why not call it quits while owning what I have always thought is the ultimate loudspeaker?e floor

 

 

1) The dog is sucking up the bass

 

2) Use REW in the way Chris suggested

 

3) While the floor might not shake if there is concrete under the rug, the couch should, just due to the wind coming from the Khorns and the subs (if you have any subs aimed at the couch).

 

4) Sometimes bass impact isn't where we think it is in the frequency spectrum.  Some of it is above the usual 80 Hz crossover (80 to about 200 Hz), so some would be coming through your Khorns.  PWK thought the bass reflection off the floor (as well as the walls, naturally) was important for Khorns.  Your platform may not be quite large enough ... may not come out far enough from the corners... to deliver that reflection uninterrupted.  You could try temporarily putting a high mass platform the same height off the floor as your current one in front of it to see if that restores some bass.  If so, build out the platform another couple of feet.  Don't do that until you try what Chris suggested.

 

I have Klipschorns and a single sub inferior to yours, coming in at 80.  The bass impact is terrific.  I tried turning off the sub out of curiosity, and found that the power of drumbeats comes mainly and magnificently through the Khorns with the crossover set @ 80 Hz.  The lowest movie effects (LFE) do come through the sub, and so do the lowest registers of instruments. 

 

Although this is quite politically incorrect, I later tried setting the Khorns to "Large," while using a subwoofer setting in the pre/pro of "LFE + Main" which allows the sub to operate while the Khorns are working full range, and, instead of there being phase cancellation & bloating, there was even more bass, without bloating.  This may not work with most rooms & MLPs, but it works with mine.

Edited April 28, 2015 by garyrc

[edzu1234]

Why not move the Horns a little forward and put a sub behind the K-horns in each corner.

[garyrc]

Why not move the Horns a little forward and put a sub behind the K-horns in each corner.

 

Normally, to get good upper bass (100 to 200 or a bit higher), you need Khorns to be pushed all the way into the corner, fairly crushing a rubber gasket, OR you need them in very rigid, high mass, artificial corners, with the Khorns sitting flat on the floor.  Or so a Klipsch tech told me a few years ago.

Edited April 29, 2015 by garyrc

[mustang guy]

Definitely look at Chris' post about doing a sweep with REW. 

 

I think gary is on to something. Those corners the Khorns are in have short ceilings with exposed joists above which may be acting as traps or at least turbulence to the bass notes. The Klipschorns rely on corners with certain properties to sound right. Those corners definitely don't look like those I've seen which work. The lowered duct above the speakers and the exposed joists... I just don't know...

 

I mentioned drywall on that ceiling and you said it was not going to happen. The next thing would be speakers with direct bass like the LaScalas, Belles, Cornwalls or Chorus. You had also mentioned replacing the Khorns with some RF towers. Those would definitely match the center better than Heritage speakers. It is most definitely worth a try.

 

Some of you think the answer is bigger subs. Michael Colter loves his THX subs, and dtel has commented that he could feel the wind from colter's THX subs from 8' away while watching Dr Who. Before you throw down coin on 18's, maybe you should get Michael involved in the conversation.

[CECAA850]

Bottom line, my opinion (for what it's worth) is that you do not have a subwoofer problem.  You have a room/phase/placement integration issue with your subs.  It will take a little work to get it right but the rewards will be worth the efforts.

[colterphoto1]

THX spec is for a 3000ft3 room. Do the math. 

[colterphoto1]

Picky has a vinyl bulb type seal on the heavy door to his basement theater. You can feel the change in the air pressure when his RSW15 kicks it. His is a smallish room, but the principles of physics apply equally. You guys are bang on with the issues being the wide open space, the numerous bass traps, possibly room modes, etc being issues for this otherwise lovely room. 

Edited April 28, 2015 by colterphoto1

[CECAA850]

THX spec is for a 3000ft3 room. Do the math. 

 

 

Did I miss the room dimensions somehow?

[colterphoto1]

 

THX spec is for a 3000ft3 room. Do the math. 

 

 

Did I miss the room dimensions somehow?

 

no, we don't even know them. How you gonna engineer something without dimensions? 

 

[CECAA850]

How you gonna engineer something without dimensions?

 

 

You said "do the math".  I was going to try.

[jimjimbo]

1) The dog is sucking up the bass

 

+1....cute though.... 

[derrickdj1]

Excellent advice in this post.  I love subs and did not mention getting any subs.  Without measurements, we are all making educated guesses that may be on the mark.  Bass problems in a room are multifactorial and will take some willingness to tackle the problem with more than one quick fix.

 

B henry said most people would be happy with the sound.  The point is he is not completely happy.  The Khorns, sub, and other gear are a sizable investment not to consider some measurement device to dial in what should be a great room of sound and stop when the answer may be so close.

Edited April 28, 2015 by derrickdj1

[CECAA850]

I've said it before.  Subs are the LEAST plug and play of any speaker.

[mustang guy]

This was the original post bhenry sent me which mentions room dimansions. I would guess about a 7 1/2' ceiling height.

 

bhenry: Thanks for the interest in my quest for more bass! Here are some pictures of the room, it is an "L" shape with the long part where the A/V equipment is being about 45/50' long and the short part around the corner is about 30' long.

 

long portion with sofa 12' x 50' = 600 sq ft

short portion with table in it 18' X 12' = 216 sq ft

600 + 216 = 816 sq ft

816 X 7.5 height = 6120 cu ft

stairway volume estimate 200 cu ft

total volume of room 6120 + 200 = 6320 cu ft, which is 320 cu ft over the 6,000 cu ft specification for two stacks of KW-120-THX subs.

 

If he builds a wall to block off back room, it would reduce the volume by:

 

12' X 30' = 360 sq ft

360 X 7.5 height = 2700 cu ft

 

And the remaining volume would be:

 

6320 - 2700 = 3620 cu ft for the HT room including volume of stairwell. With two stacks of KW-120-THX's, this would be well under the THX 6,000 cu ft specification you mentioned. There is no good way to build a door for the stairwell, but with this much overage, the room will still pressurize well if a wall is built.

 

Your thoughts?

[garyrc]

Definitely look at Chris' post about doing a sweep with REW. ...

 

... Michael Colter loves his THX subs, and dtel has commented that he could feel the wind from colter's THX subs from 8' away while watching Dr Who.

 

I can feel the wind from 13.75 feet away from a single RSW 15 sub.  But -- guess what -- when I turn off the sub and make sure the Khorns are set for full range ("Large"), I can feel the wind from the Khorns at about 16 feet away.  I used to have a table I used as a desk in the Khorn path, and during Fanfare for the Common Man (Crystal Clear direct-to-disk), the table seemed to go out of square during the timpani/bass drum/tam-tam strokes.  The table is gone now, but the Khorns alone -- at about 16 feet -- still make my pant legs flap.

Edited April 29, 2015 by garyrc

[Chris A]

This was the original post bhenry sent me which mentions room dimansions. I would guess about a 7 1/2' ceiling height.

 

bhenry: Thanks for the interest in my quest for more bass! Here are some pictures of the room, it is an "L" shape with the long part where the A/V equipment is being about 45/50' long and the short part around the corner is about 30' long.

 

long portion with sofa 12' x 50' = 600 sq ft

short portion with table in it 18' X 12' = 216 sq ft

600 + 216 = 816 sq ft

816 X 7.5 height = 6120 cu ft

stairway volume estimate 200 cu ft

total volume of room 6120 + 200 = 6320 cu ft, which is 320 cu ft over the 6,000 cu ft specification for two stacks of KW-120-THX subs.

 

If he builds a wall to block off back room, it would reduce the volume by:

 

12' X 30' = 360 sq ft

360 X 7.5 height = 2700 cu ft

 

And the remaining volume would be:

 

6320 - 2700 = 3620 cu ft for the HT room including volume of stairwell. With two stacks of KW-120-THX's, this would be well under the THX 6,000 cu ft specification you mentioned. There is no good way to build a door for the stairwell, but with this much overage, the room will still pressurize well if a wall is built.

 

Your thoughts?

 

Since the REW Room Sim utility doesn't do irregularly shaped rooms, I've just used the approximate dimensions (eyeballing the position of the couch and subs from the front wall).  The first image is the approximate low frequency response--at the listener's ears--for the current placement of the Khorns and subs, and the second image is for the same placement, except that the subs are simply moved to the front wall.  You might recommend just moving the equipment rack off to one side and placing (or stacking) the subs on the front wall between the Khorns, since the Room Sim shows a significant improvement in LF response doing just that.

 

 

Edited April 29, 2015 by Chris A

[DrWho]

Room modes....There ain't anything you're gonna do about it short of moving things around or getting into the technical details.

Using multiple subs with such different time arrival differences can be causing problems too. You may actually get more bass by turning off some of the subs.