Guys, I appreciate the ideas. Please keep in mind, however, that this is an empirical experiment, not one where I need to be concerned about the materials or the reflection. It's simply a way of finding out how much any given material works. I wouldn't refer to myself as a novice in this arena, although I always appreciate good advice.
Buscis, as for the blanket absorbing the 'bloom' and high frequencies, I assure you it's not. The high frequencies are MORE present, not less. The blanket, being porous, wouldn't likely be sufficient to damp the highs, given that sound would go 'through' the blanket. In fact, the blanket 'softened' the ceiling and allowed the highs to be heard more clearly. The lack of bloom is likely a combination of the low ceiling and the other room nodes, and I made a decision to limit the amount of work I was going to do, given that this is a family home, but my presence in it is for only a few years. Don't misunderstand: I like your suggestions, but I'm pretty aware that, if I need to make changes, I can do that with the 40 tube traps I'm bringing back from California, and I've been working with tube traps for 14 years now, so I know how to set them up.
And Jaytor, thanks for your input also; I've already damped the first and second reflection points with the Armstrong acoustic ceiling tiles. That would be the first thing I'd do. Again, this is an experiment. I hope I made it clear that this is more a fascinating experiment, not a source of consternation. I was in the euipment manager for an audio magazine for a while, so I have some understanding of necessary room treatments, although more info is better!
I'm in the process of having a 10x14x19' barn
being assembled. If I'm going to acoustically correct something, it'll be the barn, as that space is completely mine to do with as I please. |
Gbmcleod, The blanket concept is simply a temporary "fix it".
I don't know exactly how long you will be using this temporary listening area. My suggestion would be, if you are going to be using this room for any extended period of time, buy a few sheets of 4x10 x 5/8" sheetrock and a couple of rolls of "fully encapsulated" (such as Owens-Corning "Miraflex") insulation, maybe R-19 or R-30. About 1-2 hours time and some sheetrock screws will yield much better "temporary" results. Insulate the "bays" between the floor joists over your listening area and screw the sheetrock to the floor joists to create the ceiling.
Hang a blanket from the ceiling down to the floor about 3-4 feet behind your listening position. A little more work but much better results.
The "lack of openess" is probably the fact that the majority of the high frequency and "bloom" is being absorbed by the blanket. Again, I'm not sure how much time, work or money you are willing to invest, but about $75.00 and my aforementioned procedure will bring much better results. My original suggestion, I would of hoped, would bring you max results for minimum effort.
Maybe a trip to Home Depot is in order?
|
One more correction: the 'room divider I mentioned is at 15' feet from the wall BEHIND me. So the 'wall' the bass wave mainly hits is around 26-28 feet, although, obviously, with the 'divider' my mom put up being porous, it goes 'through' the divider and hits the wall. Still, some of the wave is attenuated. |
Joeb:
Thanks for the comments. The Alton Everest book is waiting for me at home. I'm curious, however, as to why you say this? Is it because it seems the room seems to be in multiples of 8? The figures were not exact for the room, just close to within 1' of exact (except for the ceiling height in the basement). As for the room length, I should have mentioned that there is a "constructed" divider (it was my mom's home) at around 15 feet,so the base wave travels less.
For all that, I found, using Buscis 2's suggestions, that using a blanket on the ceiling between the speaker and listening positions DID improve the imaging. Since all things are relevant, saying "significant" improvement might be an exaggeration; "noticeable" would be more precise. And it is quite 'noticeable.' I notice a lack of openess at the top, as in an-inivisible-force-field effect, which prevents the sound from floating freely upwards, but this is likely also an artifact of the Synergistic Reference Research .5 speaker cables (i've used the cables in other rooms, and I get the same "effect").
While Imaging is not optimal in multiples of one room dimension, my experience is that they are not absolutely impossible to attain. It's more the focus that suffers: the "outline" (as in orientation: is the image facing forward, or sidewards or even away from the microphone, as might happen in jazz during a spontaneous "jam" session). Or: the image itself is somewhat diffused and the "boundary" merges with the background, so that the image is not fully three-dimensional.
This was all an attempt to see how much could be done in a 'bad' environment. I use curiosity to see what can be attained: I KNOW what can be attained, as I've had the fortune to meet and mingle with TAS reviewers and hear 'super' systems in the manufacturers own laboratories. (Dave Wilson told me, when he let me listen to the "Puppy" woofers, that I was the first person to hear them outside of his production crew [in 1989]. I remember his room vividly and it was NOT acoustically damped in ANY way -- just very, very BIG. And the imaging was VERY, VERY good. So, apparently, room size does not preclude good imaging: wall materials, of course, DO. I've used Armstrong ceiling tiles along the side walls, as well as things like boxes of clothing (and the usual 'basement things' to interrupt the sidewall and backwall reflections). The Armstrong ceiling tiles (2' x 4'long. Cost: $2.50 per tile) made a difference, too. And, to help things along, I put two bags of sand on top of the First Presence preamp just to see what the effect was. That was an eye-opener: the volume increased by at LEAST 1 decibel, maybe more. And the sound was cleaner, which made sense. Common sense indicates that decreasing cabinet vibrations would make any component sound 'cleaner' and more focused. However, I was still surprised at how much the volume increased! For a second, I thought I'd turned up the volume pots, but since it's dual mono volume pots and I hadn't come near them, I realized that it was just the 'mass-loading' principle -- which improved the imaging. This might be why the Walker acoustic devices work: their sheer weight would decrease the cabinet resonances of whatever you place them on. Heck, I put a BOOK on top of my friend's NAD 320BEE and the volume -- and clarity -- increased. That was just something I did out of sheer instinct, I wasn't expecting anything dramatic. But dramatic it was -- or should I say 'significant'? So, I did the same thing with the preamp at home.
The bottom line is, sound can be improved in significant ways without spending $20,000 to 'fix' the room and most audiophiles, I think, do not have the luxury -- or option --
of installing wall panels, as Robert Harley did in TAS 140 (I mean, c'mon! $33,000 to improve the bloody room?!?!? What kind of realistic idea is that for someone who lives in an apartment. I even wrote Harley and got a response back from him [within a day, which seemed to conclude he was piqued by my suggestion that TAS do an article similar to ones done between issues 38-50 on room acoustics. I reminded him that nothing had been done since then]sort of snidely implying that I hadn't read his article He said (this is cut and pasted from his reply: "I agree that treating a room is of paramount importance. I stressed this in my review of the Acoustic Room Systems package a few issues back.
Thanks for reading."
He assumes I didn't read it: he's wrong. I did. But it's a review of a PRODUCT, not an ARTICLE on how the average person might improve their room significantly. This is why I was experimenting with the basement. I thought the least I could do was to install dedicated circuits, which I did. Everything else was 'homegrown' remedies. I wanted to see how cheap it COULD be to improve the sound and this is the purpose of my thread.
Buscis2: Thanks. That 'blanket' strategy helped,and, by the way, I used a THIN blanket. Next week, after I've listened a while, I'm going to put up a comforter instead and see how that helps. The most interesting thing I learned from all this is that the ceiling SIGNIFICANTLY affects the sound. Most of the articles on room improvement stress the walls and floors. Almost NOBODY ever STRONGLY RECOMMENDED ceiling treatments -- 'mildly suggested' would be more precise. Oh, Except for "Rives," above-- but that's his vocation, so he SHOULD know this. I'd tube-trapped my entire listening room in San Francisco, but NOT the ceiling. The ceiling treatments seem to improve soundstage height. Maybe Mr. Rives would like to comment on this.
It would be MOST helpful if others listed homemade improvements they've done - and the specific characteristics of sound improvement they noticed with these improvements. This can only help the whole audiophile community to take more of an interest in improving their rooms, which would in turn, benefit the companies that provide services. If you can 'fix' something with a homemade solution, and see the improvement, you're likely to have more incentive to want to hire someone to REALLY improve your sound, especially at a reasonable cost -- say, around $1,000 or so. I would. TAS used to do this in articles, and especially Enid Lumley (a la "Auntie Enid) who was the first person in TAS to seriously write about lifting speaker cables off the floor (talk about noticeable differences!! JEEZ!), power line conditioning and the like. We need more of that. For the majority of us, our components don't even sound as good as they DO 'sound' when plopped down in the average audiophile's listening room. And a new power cord isn't going to do diddly to change that. Anyone who thinks otherwise is taking the 'red' pill - or was that the 'blue' pill?!?!?! (reference to The Matrix). |
I agree with those that feel it is most likely the room acoustics. The large room size will, in general, help you, since it will reduce the frequency of the primary bass modes (although the low ceiling height is a bit of a problem here). I agree with Rives, though, that the construction of the ceiling is more important than the height.
If you've got hard concrete walls and floors, you need to do something to tame strong reflections. Make sure you have some acoustic absorption at the first reflection point on the side walls and floor. If the room is excessively bright, you can add more absorption on the wall behind the speakers, then on the wall behind the listener. Be careful about adding too much absorption, though. You don't want to make your room too dead. Substituting diffusion for absorption works well with less effect on reverberation time, but is more expensive to implement for a comparable effect.
Very hard walls will also increase the Q of the room, causing the bass modes to be narrow and strong. It doesn't sound like it's bass boominess you're complaining about though so this may not be as big a problem in your room. If it is, then some use of bass traps (RPG Modex is probably the best if you don't want to make your own) and low frequency equalization will help a lot.
Regarding your ceiling, I agree with Rives that diffusion can make a big difference, particularly with such a low ceiling. You can make polycylidrical diffusors that will fit up between the joists fairly easily. If the heavy blanket trick suggested by Buscis2 helps at all, then a broad application of diffusors will help significantly more. If you need help figuring out how to make the diffusors, let me know.
Good luck.
- Jay
http://www.jaytorborg.com |
There's no way you could have anything but horrible imaging with those room dimensions. Forget wires etc. And it's not just the ceiling height. The sound waves are traveling a 40' length, bouncing off (concrete?) walls and traveling back to you and "mingling" with the current waves "floating" past your ears. See Alton Everests books and others posted here on the topic of "resonat nodes" and standing waves, in multiple dimensions. this room would take a lot to fix. foget it and focus on your new room.
take care |
If you, on down the road, determine that your AC may be the culprit, give the Audio Magic Stealth or Matrix a shot. I had no idea how deep, wide, and detailed the soundstage could be, until I plugged my electronics into the Audio Magic. I use the Stealth Digital Mini for my front end and the Matrix for my analog. Killer sound. peace, warren |
Buscis:
Given that I have the PS Audio, which is a power regenerator, I hope that the AC issue has been scotched pretty thoroughly. If not, I want my money back!!!! (smile)
Nonetheless, I'll try it out. Empirical testing is the rule of the day. As for why I moved from CA to CT, had to. Family illness.
I'll also give the "blanket theory" a test right NOW. For the nonce, I went out and bought some Auralex bass traps, just to see if I can discern a difference in the bass response. I'll be posting later this evening, after I've put everything in place.
Now...where's the bloody blanket?!?!?!? |
BTW, I didn't mean to suggest that you do all of your listening after 11:00 pm. I was suggesting this as a part of the troubleshooting process. If you notice better results after that period, it would probably suggest that you may have an AC power issue.
Just wanted to clarify. |
I agree with your observations on ceiling height. Ceiling height is very important, but ceiling construction is even more important. We do many designs in basements where the ceiling height is 8 feet or less. Ideally we want diffusion throughout this large surface area, but do not want to sacrifice ceiling height. As such, we have designed a diffusion system that goes in the joists. In rooms using this system it sounds like the ceiling is 11 feet high instead of 8 and makes the sound stage very spacious. We have patent pending on this design |
I don't really know if ceiling height is the sole, or even the most important of your problems. There is probably lots of concrete which has its own acoustic rules. With out lots of wall treatments you are stuck with what you have. If this is temporary, I suggest you invest more energy in the room you are building and don't worry for now. A really good set of head phones helps. |
Gbmcleod, First question, why the hell would you move from Cal. to Ct? I,m looking to make the opposite move soon as my whole immediate family lives in Del Mar. But anyway.
Second question, where in Ct. do you live, as some areas in Ct. have a much higher population density in regards to factories and shopping centers, ultimately inducing much more grunge into your AC, which could really do a number on your soundstage and imaging. In fact, try doing some listening late at night (after 11 or 12 pm). I find much a more defined soundstage at these later hours.
Now, just an idea to help you troubleshoot. Try tacking or nailing a medium density blanket or comforter flat to the ceiling joists. This will negate the effects of the direction of the joists. Hang the blanket starting at about 1 foot from behind the dispersion range of the speakers and from that point, allow the blanket protrude into your listening area. See if you notice a difference.
Also, I'm assuming the floor is carpeted? Is that correct? |
