Room acoustics
Posted by: Bosh on 18 May 2002
I suspect my bass boom, exacerbated by XPS'ing the CDS2 is due to a the stud partition wall running along one end of the listening room. When thumped with the palm of the hand or an ear is pushed against it, it rumbles/resonates at more or less the problem frequency.
It has been suggested to me that-part filling the cavity with (dry) sand to mass damp the wall will help, but I have read that in time this will settle and bulge the plaster board. My dealer is coming on Tuesday to help with ways round the problem , but apart from getting in acoustic engineers (or installing very big bog rolls around the room to absorb the excess bass) has anyone any suggestions to address this?
It has been suggested to me that-part filling the cavity with (dry) sand to mass damp the wall will help, but I have read that in time this will settle and bulge the plaster board. My dealer is coming on Tuesday to help with ways round the problem , but apart from getting in acoustic engineers (or installing very big bog rolls around the room to absorb the excess bass) has anyone any suggestions to address this?
Posted on: 18 May 2002 by Allan Probin
Bosh,
The most realistic way of dealing with this would be to add another layer of plasterboard over the existing layer. Remove skirting board, attach new sheets of plasterboard (with copious quantities of PVA adhesive inbetween), re-skim and replace skirting board. Should add sufficient mass to lower the resonant frequency. May have to consult a builder to determine if the existing studding can handle the additional weight, can't see there being a problem though.
Did you get round to trying the Kans and Royds in that room ?
Allan
The most realistic way of dealing with this would be to add another layer of plasterboard over the existing layer. Remove skirting board, attach new sheets of plasterboard (with copious quantities of PVA adhesive inbetween), re-skim and replace skirting board. Should add sufficient mass to lower the resonant frequency. May have to consult a builder to determine if the existing studding can handle the additional weight, can't see there being a problem though.
Did you get round to trying the Kans and Royds in that room ?
Allan
Posted on: 18 May 2002 by Bosh
Alan
Tried the Kans but did not get on with them, they solved most of the bass problems but took the system back too many steps in other key areas.
I had a dealer demo of the Royd Minstrels, Rega Elas, Royd Doublets and s/h Shahinian Super elves with Nait 2. I found the Elves to be clearly better than the Minstrels which were better in that system context than the others. As the Elves push out more bass I was drawn to the Minstrels to prevent a repeat of the main system problems with the 2nd system. My dealer (who is aware of the main system problems) was therefore keen to come to my place and home demo the Elves and minstrels in the 2nd system and also assist with addressing the main system problems.
This happens on Tuesday.
Re The stud wall, should the 2nd layer of plasterboard go on both sides of the wall or would one side suffice?
Tried the Kans but did not get on with them, they solved most of the bass problems but took the system back too many steps in other key areas.
I had a dealer demo of the Royd Minstrels, Rega Elas, Royd Doublets and s/h Shahinian Super elves with Nait 2. I found the Elves to be clearly better than the Minstrels which were better in that system context than the others. As the Elves push out more bass I was drawn to the Minstrels to prevent a repeat of the main system problems with the 2nd system. My dealer (who is aware of the main system problems) was therefore keen to come to my place and home demo the Elves and minstrels in the 2nd system and also assist with addressing the main system problems.
This happens on Tuesday.
Re The stud wall, should the 2nd layer of plasterboard go on both sides of the wall or would one side suffice?
Posted on: 18 May 2002 by Dev B
Bosh
Some questions:
What are the dimensions of the room?
How far are you away from the speakers?
How far are speakers away from you?
How far is your head from the rear wall?
How high is the room?
How may walls are plasterboard? And where are they?
Most rooms can be fixed but in my experience there is a limit to the sort of sound you can achieve. You can email me privately and I can see if I can help.
cheers
Dev
Some questions:
What are the dimensions of the room?
How far are you away from the speakers?
How far are speakers away from you?
How far is your head from the rear wall?
How high is the room?
How may walls are plasterboard? And where are they?
Most rooms can be fixed but in my experience there is a limit to the sort of sound you can achieve. You can email me privately and I can see if I can help.
cheers
Dev
Posted on: 18 May 2002 by Allan Probin
Bosh,
I would only consider one side necessary for this sort of treatment. It would be a pity though if you went to this sort of trouble and it had little effect if the fundamental problem was due to room dimensions.
FWIW, I'm still bowled over with the performance I'm getting in my problem room with the Epos ES11s (upgraded by Epos with ES12 drivers). Considering a new pair (now called M12's) are only £430 I would consider them a bargain. I'm converted now to the belief that in these situations you need the flexibility of free-space placement in order to tune your speaker to the room.
Allan
I would only consider one side necessary for this sort of treatment. It would be a pity though if you went to this sort of trouble and it had little effect if the fundamental problem was due to room dimensions.
FWIW, I'm still bowled over with the performance I'm getting in my problem room with the Epos ES11s (upgraded by Epos with ES12 drivers). Considering a new pair (now called M12's) are only £430 I would consider them a bargain. I'm converted now to the belief that in these situations you need the flexibility of free-space placement in order to tune your speaker to the room.
Allan
Posted on: 18 May 2002 by Bosh
Hi Dev
The house is new and the listening room is 17'2" x 12'2" x 8' high with french doors at one end. The walls are drylined on 3 walls with 4th being a 12'2" wall opposite the french doors.
My listening position is halfway along one of the long walls with the SBLs placed either side of a fireplace on the opposite long wall and the CDS2/52/135 on 2 x 4 shelf high Fraims 6" from the stud wall.
I have experimented extensively with all elements of setup especially so with SBL placement which makes a big difference to the sound. The best position I have found is 8'2" apart (tweeter to tweeter). Any further apart and a hole opens in the middle of the soundstage and any closer together a hard edge appears in the sound making piano and vocals very hard edged. The SBLS are as close to the skirting as I can get without touching and angled backwards to bring them again as close to the wall as possible without touching. Parallel to the wall the "hard edge" is present but removed by toeing towards the listening position.
In the listening position my head is 12-18 inches from the wall and on may recordings the boom is removed by moving further into the room. These measure have resloved the problem on all bar a couple of LPs but remains a problems on many CDs (Lambchop/latest Ferry/Eels/in fact at least a couple of track on most well recorded albums with "decent" bass) inflicting problems much further up the frequency band (ie chesty vocals etc)
The house is new and the listening room is 17'2" x 12'2" x 8' high with french doors at one end. The walls are drylined on 3 walls with 4th being a 12'2" wall opposite the french doors.
My listening position is halfway along one of the long walls with the SBLs placed either side of a fireplace on the opposite long wall and the CDS2/52/135 on 2 x 4 shelf high Fraims 6" from the stud wall.
I have experimented extensively with all elements of setup especially so with SBL placement which makes a big difference to the sound. The best position I have found is 8'2" apart (tweeter to tweeter). Any further apart and a hole opens in the middle of the soundstage and any closer together a hard edge appears in the sound making piano and vocals very hard edged. The SBLS are as close to the skirting as I can get without touching and angled backwards to bring them again as close to the wall as possible without touching. Parallel to the wall the "hard edge" is present but removed by toeing towards the listening position.
In the listening position my head is 12-18 inches from the wall and on may recordings the boom is removed by moving further into the room. These measure have resloved the problem on all bar a couple of LPs but remains a problems on many CDs (Lambchop/latest Ferry/Eels/in fact at least a couple of track on most well recorded albums with "decent" bass) inflicting problems much further up the frequency band (ie chesty vocals etc)
Posted on: 19 May 2002 by Don
Bosh
Excuse me, but how do you run the CDS2 w/o having an XPS in the first place?
Excuse me, but how do you run the CDS2 w/o having an XPS in the first place?
Posted on: 20 May 2002 by Bosh
Don
No - I upgraded the CDS1 head to CDS2 last year and continued to use the CDS1 power supply which I have just upgraded to XPS. This obviously puts out more bass in the bass frequency region where I have the room acoustics problem.
Interestingly a demo of upgrading power supply form Hicap on the Prefix to Supercap showed this to remove all boom tendencies from the LP12 and I was hoping the XPS would do the same for the CDS2
An excellent example of the necessity for home demo at this level
No - I upgraded the CDS1 head to CDS2 last year and continued to use the CDS1 power supply which I have just upgraded to XPS. This obviously puts out more bass in the bass frequency region where I have the room acoustics problem.
Interestingly a demo of upgrading power supply form Hicap on the Prefix to Supercap showed this to remove all boom tendencies from the LP12 and I was hoping the XPS would do the same for the CDS2
An excellent example of the necessity for home demo at this level
Posted on: 20 May 2002 by Dev B
Sorry for the delay in replying, has to visit the outlaws and pariods this weekend...
Anyway, lets see...
OK, not bad dimensions, but hmmmm, drylined walls can be problematic as Allan has suggested in one of his posts earlier.
Does that make your listening seat about 9 feet away then? This should be okay but is nearing the minimum for SBL's - i.e in my experience assuming an solid rear wall about 2 ft behind you and a 9 foot ceiling on top of you, you should be sitting about 10-12 feet way for proper integration with SBL's
I reckon the problem is that your rear wall is reflecting tne mid-bass and is causing the confusion in the sound. You need a combination of absorption (sp?) and diffusion. Try and make a diffuser (you don't need those panels from RPG) and stick it in the wall behind you then, hopefully, given how far apart your speakers are all the bass should disappear, and everything should should really bass light. Then you wil have to being the speakers closer together (say 6 feet) to get a natural bass balance without bloom.
Having said all that, is it not possible put the SBL's along the short wall firing along the length of the room? I would try this to see if you like the character of the sound.
If all of that fails you could try active, or plinths under your speakers.
regards
Dev
you can email me privately if you want to talk about this
Anyway, lets see...
quote:
The house is new and the listening room is 17'2" x 12'2" x 8' high with french doors at one end. The walls are drylined on 3 walls with 4th being a 12'2" wall opposite the french doors.
OK, not bad dimensions, but hmmmm, drylined walls can be problematic as Allan has suggested in one of his posts earlier.
quote:
My listening position is halfway along one of the long walls with the SBLs placed either side of a fireplace on the opposite long wall and the CDS2/52/135 on 2 x 4 shelf high Fraims 6" from the stud wall.
Does that make your listening seat about 9 feet away then? This should be okay but is nearing the minimum for SBL's - i.e in my experience assuming an solid rear wall about 2 ft behind you and a 9 foot ceiling on top of you, you should be sitting about 10-12 feet way for proper integration with SBL's
quote:
In the listening position my head is 12-18 inches from the wall and on may recordings the boom is removed by moving further into the room. These measure have resloved the problem on all bar a couple of LPs but remains a problems on many CDs (Lambchop/latest Ferry/Eels/in fact at least a couple of track on most well recorded albums with "decent" bass) inflicting problems much further up the frequency band (ie chesty vocals etc
I reckon the problem is that your rear wall is reflecting tne mid-bass and is causing the confusion in the sound. You need a combination of absorption (sp?) and diffusion. Try and make a diffuser (you don't need those panels from RPG) and stick it in the wall behind you then, hopefully, given how far apart your speakers are all the bass should disappear, and everything should should really bass light. Then you wil have to being the speakers closer together (say 6 feet) to get a natural bass balance without bloom.
Having said all that, is it not possible put the SBL's along the short wall firing along the length of the room? I would try this to see if you like the character of the sound.
If all of that fails you could try active, or plinths under your speakers.
regards
Dev
you can email me privately if you want to talk about this