seti Posted July 15, 2004 Share Posted July 15, 2004 I have never really thought about room size or dimensions as important to my audio system but from what I have read in these forums some of you consider it to be one of the most important factors. It is not a home theatre just a 2way system belles with 300b 8wpc set. I just purchased a home and have 3 different rooms that I could turn into an audio room. Which of these should I choose and they all have 15ft ceilings? 13 x 8 14 x 11 14 x 14 Thanks, Seti Quote Link to comment Share on other sites More sharing options...
damonrpayne Posted July 15, 2004 Share Posted July 15, 2004 15 foot ceilings? Wow. Uhm, I'm going to guess 14x11 but it may well sound pretty funky with a ceiling that is higher than either room dimension. Artto? Quote Link to comment Share on other sites More sharing options...
dodger Posted July 15, 2004 Share Posted July 15, 2004 Hello: Have you tried a search on either the Forum or going to Google and typing proper room size + 15 ' ceilings? I hope this helps. dodger Quote Link to comment Share on other sites More sharing options...
Champagne taste beer budget Posted July 15, 2004 Share Posted July 15, 2004 I'd start here: http://www.realtraps.com/modecalc.htm It will give you the basic room modes based on the dimensions. Definatly stay away from the square room, especially as close as it is to the height, I got double modes at 40Hz, 80 Hz, 121 Hz, etc going up by 40, which would be a nightmare to try and correct for. Keep the room somewhat oblong to eliminate double resonances. I'd choose the 14x11 just because it's bigger and will have less of a problem with modes than the 13x8, although they both appear to have 13 modes below 200 hz. Best of luck, and start saving money for room treatments!!! They all need some to some extent, and even DIY can be fairly spendy. edit. Actually, if you play with the mode calculator, you might find that one of the rooms works out pretty well if you lower the ceiling some. Check the other posts in this forum as to the best way, avoid a dropped ceiling if you can. Quote Link to comment Share on other sites More sharing options...
picky Posted July 16, 2004 Share Posted July 16, 2004 Naturally, I bow-to-the-master (artto) here, but it has been my understanding that the closer all room dimensions are to being equal (cube-like), the worse the sound is. So I would guess that to make your room 14 x 14 x 15 might produce terrible results. Also, I seem to remember that the 12-foot dimension had a huge significance because it approximates the size of a full wave, down in the lower bass region, thereby causing all sorts of havoc with room resonance and standing waves. And, because of this, any dimension of 12 feet should be avoided. IMO: Although very small, I would vote for the 13 x 8 x 15 room. Number two would be 14 x 11 x 15. Artto, please correct me if I am way off base here! Or, is that "bass"? LOL Quote Link to comment Share on other sites More sharing options...
seti Posted July 16, 2004 Author Share Posted July 16, 2004 Wow thanks for all the advice. It is a little over my head so I should start to read the f*ing manual. lol.... I went back and actually measured the ceilings for myself and only one room in the house has 15ft ceilings and that is the kitchen lol no klipsch there. The other rooms are 12ft ceilings. I'll check out the modecalc. I have an attic that could be converted to living space but i bet the slanted ceilings wouldn't help..... Thanks again! Quote Link to comment Share on other sites More sharing options...
DrWho Posted July 17, 2004 Share Posted July 17, 2004 ---------------- On 7/16/2004 8:34:42 AM picky wrote: Also, I seem to remember that the 12-foot dimension had a huge significance because it approximates the size of a full wave, down in the lower bass region, thereby causing all sorts of havoc with room resonance and standing waves. And, because of this, any dimension of 12 feet should be avoided. ---------------- 12ft? I think you might mean 19ft which correlates to 60Hz which is the frequency that most humming occurs. AC power operates at 60Hz and any imperfect ground is going to create some amount of 60Hz hum...usually it's inaudible, but a room of 19ft is going to amplify it and most likely make it audible. As far as room choice, my instinct would say to go with the 14x11 room. Bigger is usually better when it comes to rooms for audio. If you find that altering the dimensions might provide a better modal response, then you could take the bigger room and fill in some space with some acoustical material and kill two birds with one stone (improving bass response while treating flutter echoes or reverberation and whatever else that might be hurting your sound). Also, a bigger room allows for more and bigger gear Quote Link to comment Share on other sites More sharing options...
artto Posted July 17, 2004 Share Posted July 17, 2004 All of these rooms are rather small for good acoustical properties. Usually a high ceiling is a benefit, but in these circumstances it is not an advantage. Ironically, the 14x14 room has the best mode distribution (49 modes below 150Hz), however since the room is nearly cubical the modes spacing becomes very severe with very large peaks and dips. The 13x8 room has only 29 modes and the 14x11 room 40 modes (below 150Hz) (typically the more modes the better as this usually creates smaller peaks and dips for each mode). Rooms of these sizes are best used with what are called near-field monitors, which is what they use in smaller recording studios. Basically, youre trying to put a Ferrari engine (Belles) in Chevette (the room). In this kind of situation Id almost be inclined to use a 32 band equalizer, EQd for one specific listening position. Belles are large speakers, and although not nearly as large as Khorns, they still need some room to breath, for the sound to open up and for the bass to bloom (instead of boom and/or null out). Thats one of the reasons you dont see recording studios using speakers like this in their small control rooms. They will never yield anything close to smooth and reasonably flat (I use that word with hesitation because you dont really want the response flat for listening, there usually should be a flat roll off with increasing frequency) response, especially in the bass range. And lets not forget that the bass range encompasses nearly half of the musical frequency range. Its also what provides the fullness and power to the music. If you have many severe dips in the lower frequency range youre going to be missing much of the impact and dynamics of the music. http://www.audioholics.com/techtips/setup/RoomAcoustics-RivesAudio.html http://www.audioholics.com/techtips/setup/acoustics/BassTraps.html Quote Link to comment Share on other sites More sharing options...
artto Posted July 17, 2004 Share Posted July 17, 2004 ---------------- On 7/16/2004 8:34:42 AM picky wrote: Also, I seem to remember that the 12-foot dimension had a huge significance because it approximates the size of a full wave, down in the lower bass region, thereby causing all sorts of havoc with room resonance and standing waves. And, because of this, any dimension of 12 feet should be avoided. ---------------- Dr. Who is correct, it is the 19 foot dimension that is to be avoided. Quote Link to comment Share on other sites More sharing options...
artto Posted July 17, 2004 Share Posted July 17, 2004 Using 12' for the ceiling height in the 14x14 room still yields the greatest number of modes (41 below 150Hz) with a mode spacing of 2.2Hz. The 14x11 room has 33 mode with a spacing of 2.7Hz. The 13x8 room 24 modes with a spacing of 4.1Hz. The 14x14 room still wins and is far from anywhere near ideal. My previous comments still apply. Sorry, wish I had better news, but it all really starts with the room (not ends there). Unfortunately, for most audiophiles, its the last thing given any consideration (if at all). Quote Link to comment Share on other sites More sharing options...
DA1984 Posted July 17, 2004 Share Posted July 17, 2004 My new room is going to be 19.8 L x 12.2 W x 8 H. Will this be a good size? Quote Link to comment Share on other sites More sharing options...
artto Posted July 17, 2004 Share Posted July 17, 2004 ---------------- On 7/17/2004 12:25:55 PM DA1984 wrote: My new room is going to be 19.8 L x 12.2 W x 8 H. Will this be a good size? ---------------- In this room there are only 36 modes below 150Hz with an average mode spacing of 2.6Hz (fair to not so good). Most of your mode problems in this room will be with peaks rather than dips, at 46.2Hz, 57Hz, 70.5Hz, 85.5Hz, 92.5 Hz, 114Hz, 138.7Hz and 142.5Hz. These peaks can often cause cancellations at the listening position, however these peaks should be able to be tamed to some extent with bass traps in the corners. So while this room is not near the ideal proportions either, you should be able to manage some of its problems with proper acoustical treatment. It would help if the room were much deeper, say 15-17'. Quote Link to comment Share on other sites More sharing options...
DA1984 Posted July 17, 2004 Share Posted July 17, 2004 The room is actually deeper than 15-17ft, its 19.8 ft, or am I misunderstanding you. It will have a 60in TV at one end and a 3 quarter sectional at the other, so the corners are couch in the rear and one is SVS cylinder in the front. I acctually thought it would be a little better than that. Take a look the pic is attached. Quote Link to comment Share on other sites More sharing options...
artto Posted July 17, 2004 Share Posted July 17, 2004 ---------------- On 7/17/2004 3:03:22 PM DA1984 wrote: The room is actually deeper than 15-17ft, its 19.8 ft, or am I misunderstanding you. ---------------- The width or depth is 12.2 feet. 19.8 is the length. However, these just terms. It's the dimensions in relationship to each that are important. Basically the height to width to length ratios should be 1:1.26:1.59 for optimum performance. The mode calculator I use is a little more sophisticated and uses the following formula: Acceptable if 1.1*(W/H) < (L/H) < 4.5*(W/H)-4 the above= 2.3 2.5 5.6 Quote Link to comment Share on other sites More sharing options...
DA1984 Posted July 17, 2004 Share Posted July 17, 2004 Any further suggestions based on the attachement? Quote Link to comment Share on other sites More sharing options...
artto Posted July 17, 2004 Share Posted July 17, 2004 If it were my room, I'd seal the doorways off with air tight doors, if anything just to cut down on noise. Quote Link to comment Share on other sites More sharing options...
seti Posted July 17, 2004 Author Share Posted July 17, 2004 I simply had no idea room size mattered so much. Thanks for all the input perhaps i'll just tear down one of the walls and extend the room. So what are the magic deminsions for a room to house a pair of belles anyhow? Quote Link to comment Share on other sites More sharing options...
formica Posted July 18, 2004 Share Posted July 18, 2004 ---------------- On 7/17/2004 11:09:27 AM artto wrote: the 14x14 room has the best mode distribution (49 modes below 150Hz), however since the room is nearly cubical the modes spacing becomes very severe with very large peaks and dips. ---------------- Yes, and I'm figuring that the mode spacing will probably have a greater influence than the number of modes esp with a 14x14x15 room. (the 14x14x12 is slightly better). Guess you could try either room if you don't mind dragging around the Belles... Rob Quote Link to comment Share on other sites More sharing options...
picky Posted July 19, 2004 Share Posted July 19, 2004 Dr. Who & artto: Thanks for straightening me out, guys! I don't know where I got that "12-foot" dimension from! 19 makes more sense, to me now. Quote Link to comment Share on other sites More sharing options...
artto Posted July 19, 2004 Share Posted July 19, 2004 ---------------- On 7/17/2004 6:07:17 PM seti wrote: I simply had no idea room size mattered so much. Thanks for all the input perhaps i'll just tear down one of the walls and extend the room. So what are the magic deminsions for a room to house a pair of belles anyhow? ---------------- It's not so much room size as it is room proportions. As the room gets larger and larger, eventually the room modes no longer matter because any of the room dimensions are longer than the wavelengths of the lowest frequencies being produced. The "ideal" room proportions are posted in my post, six posts up. This only a guideline, as there are many good sounding rooms that fall outside of this criteria. Richard Bolt (a renown acoustician) ( http://www.fact-index.com/b/bo/bolt__beranek_and_newman.html ) indicated a preference of room ratios ranging from 1:1.5:2.5 (nearly 'golden mean') to 1:1.26:1.59 (height:width:length). (see Klipsch Dope From Hope Vol.9, No.1 Feb 1968 available in "The Paper" I prepared & is available in PDF format from Justin's website www.soundwise.org) These proportions have nothing to do with any particular speaker although the Klipschorn, because of it's mandatory corner placement to achieve maximum performance at lower frequencies is capable of exciting any and all room modes. This can be a good thing, or a bad thing, depending on how well distributed the room modes are. This is why there are so many different perceptions as to Klipschorn "sound", some saying it has boomy or bloated mid bass, while others say it has no low bass, etc. Quote Link to comment Share on other sites More sharing options...
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