Boom
Posted by: mrm on 26 February 2003
Hi guys,
I have always sufferred with boom from my Credos at about 80-100hz, while at any other frequency sounds are clear and tight. I have tried the usual things like moving the speakers/furniture, etc with little real success. The only improvements have been through equipment upgrades. I have always had this problem, even when I had non Naim amps and speakers.
Anyway the point of this... at the Bristol show I was talking to the techy guy for Spendor speakers (I forget his name), who has Naim gear, he said it sounded as though the problem was the ceiling, rather than the room or the walls. Anyone any experience of this? It sounds reasonable to me, does anyone think that putting insulating material in the ceiling cavity would help?
Aside from this would going active with an IXO and another NAP 140 allow me enough control to affect the troublesome frequency?
Current system is CDX/Rega P3/NAC82/NAP140/Credos
Any suggestions appreciated.
I have always sufferred with boom from my Credos at about 80-100hz, while at any other frequency sounds are clear and tight. I have tried the usual things like moving the speakers/furniture, etc with little real success. The only improvements have been through equipment upgrades. I have always had this problem, even when I had non Naim amps and speakers.
Anyway the point of this... at the Bristol show I was talking to the techy guy for Spendor speakers (I forget his name), who has Naim gear, he said it sounded as though the problem was the ceiling, rather than the room or the walls. Anyone any experience of this? It sounds reasonable to me, does anyone think that putting insulating material in the ceiling cavity would help?
Aside from this would going active with an IXO and another NAP 140 allow me enough control to affect the troublesome frequency?
Current system is CDX/Rega P3/NAC82/NAP140/Credos
Any suggestions appreciated.
Posted on: 26 February 2003 by mrm
Nick,
Thanks for the suggestion, however I have tried a 250. It brings a bigger sound, and in my room this is too much. There is more control, but I didn't like it. As volume increases so does the boom problem. The 250 needed to be played louder to sound 'right'if that makes any sense. Can't say about a 180. The 140 and 250 seem similar in overall presentation with the 250 giving more. Will a 180 give extra control without the bigger sound of a 250?
Thanks for the suggestion, however I have tried a 250. It brings a bigger sound, and in my room this is too much. There is more control, but I didn't like it. As volume increases so does the boom problem. The 250 needed to be played louder to sound 'right'if that makes any sense. Can't say about a 180. The 140 and 250 seem similar in overall presentation with the 250 giving more. Will a 180 give extra control without the bigger sound of a 250?
Posted on: 26 February 2003 by Mr_Sukebe
Have you checked around the room for things that are lose?
This Sunday I came home and had a good listen to my system to see how well/badly it compared to those at the show. What I was surprised to hear was what sounded like the left speaker really "booming" away. I wasn't even sure of the problem as it's never done it before.
Either way, took 10 mins to figure it out. Turned out that it was the kitchen door, which I'd left slightly adjar. As I was playing the system at pretty loud volumes, the bass was actually resonating the door. Closing it did help, but it certainly shows something about room acoustics. Go check around your room for lose objects!
This Sunday I came home and had a good listen to my system to see how well/badly it compared to those at the show. What I was surprised to hear was what sounded like the left speaker really "booming" away. I wasn't even sure of the problem as it's never done it before.
Either way, took 10 mins to figure it out. Turned out that it was the kitchen door, which I'd left slightly adjar. As I was playing the system at pretty loud volumes, the bass was actually resonating the door. Closing it did help, but it certainly shows something about room acoustics. Go check around your room for lose objects!
Posted on: 26 February 2003 by Rockingdoc
I would try the system in another room as a test. Even if this is impractical, e.g. bedroom, it should allow you to see if you have a room problem or a gear problem.
malcolm
p.s. going active is great, but unlikely yo solve your problem
malcolm
p.s. going active is great, but unlikely yo solve your problem
Posted on: 26 February 2003 by Bosh
What is the construction of the rest of the room?
I have a problem room due to what I thought was either drylined walls (3) and/or 12 foot stud partition wall (1) and/or chimney resonance, never though it may be the ceiling.
The point I make is I too suffered similar problems (52/135/SBL) when I moved house for which I could not get consistent advice on how to solve. The opinions varied from to mass damp or non mass damp the stud wall, strip the dry-lining and traditionally render, use rather cumbersome bass traps (either panels or 6-8 4foot tubes around the room!!).I opted not to do anything due to the potential mess of most options or lack of WAF for the traps.
I did experiment endlessly with mains spurs and blocks ( tightened the bass and removed some boom) and speaker positioning (made a significant difference in many ways not just bass) within the limits of a WAF room layout (I was unable to try them on a different wall)
The problem is still there to some extent on certain discs but the real improvement came from the massive control gained from dropping in a NAP500. If all else fails another option you may want to consider is going active so you can tweak the bass with the crossover.
I would however caution you to home demo any future hardware upgrades very carefully. I found that just upgrading the black SNAIC on the prefix pushed the bass on the LP12 over the edge and wished I hadnt had it fitted!!!
NB: WAF =wife acceptabilty factor
I have a problem room due to what I thought was either drylined walls (3) and/or 12 foot stud partition wall (1) and/or chimney resonance, never though it may be the ceiling.
The point I make is I too suffered similar problems (52/135/SBL) when I moved house for which I could not get consistent advice on how to solve. The opinions varied from to mass damp or non mass damp the stud wall, strip the dry-lining and traditionally render, use rather cumbersome bass traps (either panels or 6-8 4foot tubes around the room!!).I opted not to do anything due to the potential mess of most options or lack of WAF for the traps.
I did experiment endlessly with mains spurs and blocks ( tightened the bass and removed some boom) and speaker positioning (made a significant difference in many ways not just bass) within the limits of a WAF room layout (I was unable to try them on a different wall)
The problem is still there to some extent on certain discs but the real improvement came from the massive control gained from dropping in a NAP500. If all else fails another option you may want to consider is going active so you can tweak the bass with the crossover.
I would however caution you to home demo any future hardware upgrades very carefully. I found that just upgrading the black SNAIC on the prefix pushed the bass on the LP12 over the edge and wished I hadnt had it fitted!!!
NB: WAF =wife acceptabilty factor
Posted on: 26 February 2003 by NaimDropper
Bosh and Rockingdoc are on to something here, it's probably room resonance.
For an experiment, try hanging a heavy curtain or some other sound dampening material in various places around the room and see if it goes away.
I don't know how tough it would be to put insulation in your ceiling, but it sounds like that may be a last resort.
Remember that a 100 Hz wave is about 11 feet long, so you can have resonance at that frequency with cavities with lengths of half that and multiples of that half.
Since your ceiling rafters are probably running one direction, try moving the speakers to an adjacent wall and see if it changes or goes away...
Good luck!
David
For an experiment, try hanging a heavy curtain or some other sound dampening material in various places around the room and see if it goes away.
I don't know how tough it would be to put insulation in your ceiling, but it sounds like that may be a last resort.
Remember that a 100 Hz wave is about 11 feet long, so you can have resonance at that frequency with cavities with lengths of half that and multiples of that half.
Since your ceiling rafters are probably running one direction, try moving the speakers to an adjacent wall and see if it changes or goes away...
Good luck!
David
Posted on: 26 February 2003 by mrm
Many thanks for the suggestions guys. The walls of the room are plasterboard (yes I know)except for the chimney which is solid plaster. I have tried hanging curtains on various parts of the walls... the effect is marginal.I have also filled the wall cavity behind the speakers with foam since this was the closest point of possible vibration to the speakers. It did give positive results, boom was considerably reduced. (It went from really awful to just bad.)
Once again thanks.
Once again thanks.
Posted on: 26 February 2003 by Bosh
Just a note of caution, I was advised to fill the wall cavity with expanding foam to damp it .However there is a serious risk in doing this of separating the plaster board and the walls.
I was also advised to fill the cavity with sand to mass-damp them but there is a risk of the sand absorbing water, expanding and rotting the plasterboard or pushing it off the wall
The following provided me a test CD FOC to analyse boom frequency (60Hz): http://www.absoluteaudio.co.uk/ Let me know if you try any of their products and they work (Michale Dale said he was getting their RATS here: http://forums.naim-audio.com/eve/forums?a=tpc&s=67019385&f=48019385&m=8051908584&r=7521931784#7521931784
[This message was edited by Bosh on WEDNESDAY 26 February 2003 at 13:44.]
I was also advised to fill the cavity with sand to mass-damp them but there is a risk of the sand absorbing water, expanding and rotting the plasterboard or pushing it off the wall
The following provided me a test CD FOC to analyse boom frequency (60Hz): http://www.absoluteaudio.co.uk/ Let me know if you try any of their products and they work (Michale Dale said he was getting their RATS here: http://forums.naim-audio.com/eve/forums?a=tpc&s=67019385&f=48019385&m=8051908584&r=7521931784#7521931784
[This message was edited by Bosh on WEDNESDAY 26 February 2003 at 13:44.]
Posted on: 26 February 2003 by garyi
Guys the cavity isn't just there for the hell of it, leave it alone!
When I had credeos the best sound came from toeing in slightly (yes I know) and insuring the spikes are as far in as possible and that they rest on two penny peices.
If you are on carpeted wood floor put some cross head screws in where the spike inpact and offer the spikes up to the corss heads,
In any case a rock solid platform needs to be available for the leaf spring at the back, other wise it will flap like a beast.
When I had credeos the best sound came from toeing in slightly (yes I know) and insuring the spikes are as far in as possible and that they rest on two penny peices.
If you are on carpeted wood floor put some cross head screws in where the spike inpact and offer the spikes up to the corss heads,
In any case a rock solid platform needs to be available for the leaf spring at the back, other wise it will flap like a beast.
Posted on: 26 February 2003 by phil. S
Sorry MRM
I purchased second hand Credos from my dealer about 2 years ago. They never sounded right in my room..too much bass boom. To his credit the dealer tried everything to cure them. I had the latest crossovers fitted, but this only made things worse.
After about 6 weeks I solved the problem.
I bought a pair of JM Lab Elektra 906s'...brilliant.
I and my dealer put the problem down to room acoustics. My wife wouldn't entertain foam things stuck around the room so the Credos had to go.
I must say that I have never regretted buying the JM Labs.
Cheers
Phil
I purchased second hand Credos from my dealer about 2 years ago. They never sounded right in my room..too much bass boom. To his credit the dealer tried everything to cure them. I had the latest crossovers fitted, but this only made things worse.
After about 6 weeks I solved the problem.
I bought a pair of JM Lab Elektra 906s'...brilliant.
I and my dealer put the problem down to room acoustics. My wife wouldn't entertain foam things stuck around the room so the Credos had to go.
I must say that I have never regretted buying the JM Labs.
Cheers
Phil
Posted on: 26 February 2003 by J.N.
MRM
I've suffered from room problems and reckon that modern houses (mine was built about 1980) can produce a generally poor sound, due to relatively flimsy construction.
Older, more solidly built properties (particularly with higher ceilings) seem to be a lot better.
A friend reported a substantial improvement by putting good quality underlay and carpet in the room ABOVE the listening room.
DO NOT throw money at the system. You've learned that a 250 just pumps out a bigger more powerful sound that the room has to deal with.
Work on the room. In an acoustically great room, a modest system will sound great.
Good luck.
I've suffered from room problems and reckon that modern houses (mine was built about 1980) can produce a generally poor sound, due to relatively flimsy construction.
Older, more solidly built properties (particularly with higher ceilings) seem to be a lot better.
A friend reported a substantial improvement by putting good quality underlay and carpet in the room ABOVE the listening room.
DO NOT throw money at the system. You've learned that a 250 just pumps out a bigger more powerful sound that the room has to deal with.
Work on the room. In an acoustically great room, a modest system will sound great.
Good luck.
Posted on: 27 February 2003 by garth
The last couple fo weeks have been spent preparing for a move. I began by laoding boxes into the listening room. After stacking maybe 20 boxes strategically about the room my system - planet/planar, 32.5/90, ninka - sounded far better. I realized how much I had been losing to my rather reverberant room. Everything was tighter, more prat, bass was tighter and more tuneful, highs less tizzy, everything richer, while at the same time more detailed and rhythmic. A major upgrade.
After loading perhaps another 20 boxes and other absorbent clutter the sound just died. Dry and constipated. Sounded like it was playing in marshmellow.
The moral of the story, for me, is that the room is probably the most important single component in a system, and, if you don't mind living surrounded by ugly boxes and packing material, it can be dramatically, cheaply, and easily improved or tuned to your liking.
Garth
After loading perhaps another 20 boxes and other absorbent clutter the sound just died. Dry and constipated. Sounded like it was playing in marshmellow.
The moral of the story, for me, is that the room is probably the most important single component in a system, and, if you don't mind living surrounded by ugly boxes and packing material, it can be dramatically, cheaply, and easily improved or tuned to your liking.
Garth