artto

Gotcha! I toyed with the idea of doing something wood panels like that but, as you said, it can be expensive. I was opting for something more contemporary, which I guess you could still do with the wainscots. My second reason for going with the large polycylidrical panels was that they can be bowed deeply enough to actually start damping standing waves in the bass range. But you also need the space to do this. Bowing these things 12-18" can take a lot of space out of the room.

I think I'm going to go with the New York Audio Laboratories $250,000.00 power amps & plug them into some car speakers hung in the middle of the room. At that price they should be able to make anything sound glorious. I also like the $750 3to2 prong power cord adaptors with built-in flasher. (what the hell is the matter with some of these "manufacturers"? I'm in the wrong business. Guess I'm not very good at being a con artist).

You sure that person is a "friend"? Maybe they are trying to tell YOU something! LOL

I have a reprint of a paper PWK published in the Journal of the Audio Engineering Society comparing modulation distortion in various loudspeakers, with horn-loaded ones that included spectrograms of the sideband distortion products. One section titled "Test of Full-Range Loudspeker" describes the following: "The speaker choosen for the test was direct radiator consisting of several small cone loudspeakers of 'long throw' capability and with a total area approximating that of a 12 inch cone loudspeaker. This system was intended for 'full frequency range' and normally employed an equalizer." Sound familiar? Gee. Now this just couldn't be the Bose 901 direct reflecting crap now could it? One look at the spectogram of this speaker is enough to make you puke. 14% total modulation distortion (95Db SPL reference). The second sidebands (distortion) are nearly half the height of the 2 fundamental test tones and even 50% higher than the first sidebands. As PWK put it: "Its easy to ignore sideband amplitudes of less than 3% when there are distortion amplitudes exceeding 10%. It would also be interesting to find the causes of these unpredicted distortion products, but the cone loudspeaker with its infinite number of modes of vibration and breakup could take a lifetime of studying third order effects." "In the case of the multiple loudspeaker whose performance is shown in Fig. 3 (the spectrogram mentioned above), obviously the mere proliferation of the number of loudspeakers fails to reduce distortion to tolerable levels. In the companion paper, a horn woofer was tested at 100Db SPL and found to produce less than 1% total modulation distortion". Thats the reality of why BOSE BLOWS. If you like your music full of distortion, go with Bose.

TOOL The first TOOL CD is immaculate. Clean as a whistle. Crank the hell out it! John Paul Jones'(of Led Zep fame, bass player) CD 'Zooma' is extremely intense. uh....just some food for thought as long as we're on the subject of music..... Everytime I play Stevie Ray Vaughn my dog comes downstairs & plants himself in the center of the music room. He does this everytime. There are no exceptions. My previous dog died the night before Stevie did. When I put on Pink Floyd he leaves (I like Pink Floyd). Once, a David Bowie tune was playing on the radio. My wife leaves to check on dinner. The dog always follows her. This time the dog stays. You guessed it! The Bowie song is from the Lets Dance LP. SRV is playing on it. When I put on TOOL, he throws up. This has happened several times. Needless to say, I remove the dog from the music room when TOOL gets played since it seems to make him sick so fast that he doesn't even get up & leave.

I wrote Klipsch about this subject many years ago. Their letter to me recommended either the LaScala or Belle for the center channel use with Klipschorns due to their horn loaded bass (tonal balance of the speakers is more similar to K-horn) & lower thru center distortion.

Glad I ran into this discussion! I was wondering about all this stuff too. Back in May or June I finally got someone in engineering to talk with me on the phone about the pic with PWK. I was wondering if this was new version of the Klipschorn. This is what I was told: It is called the Jubilee. It was PWK's last pet project. It was scheduled for release late this year. The wood is African Mahogany. Its a 2-way system. They were having some problems finding a suitable OEM source to build the upper frequency horn to their specifications, cost and production requirements. They were still considering alternative construction methods/materials such as a carbon fiber composite or carbon fiber composite with a Mahogany laminate, etc. The upper frequency horn utilized a 3" titanium diaphragm compression driver. The speaker was designed to not be as sensitive to room acoustics & did not require stringent corner placement like K-horns. The estimated retail price......hold on to your seats folks............. $17,000 I don't remember if that was a pair, or each. BTW, I remember some of the earliest K-horns were 2-way. I even have pictures of them with the tweeters mounted vertically & to the side of the midrange horn. I also seem to recall seeing some pics where they tried co-axially mounting the tweeter inside of the midrange horn at one time.

Well, I'm going to have to disagree. An acoustic wave front, is an acoustic wave front. Physics doesn't care if its a sine wave or a dynamic complex signal. The cancellations will still be there. Whether or not its audible to certain individuals under specific conditions is a subjective call for sure. But consider that you're not dealing with a situation like a complete speaker system that has crossover networks where you can compensate for time delay & phase errors between the drivers thereby reducing comb filter effects. I also can't understand the purpose of placing two "center speakers" 5 feet apart. This may reduce comb filter effects between the two speakers but it also seems to me that it would just spread the center imaging apart, which is completely the opposite of what a center channel is supposed to do. May I borrow a phrase from one of my architect cohorts? Seems like this is a prime example where "Less is More". The KISS method also comes to mind.

There sure are a lot of misconceptions out there. I would question the use of styrofoam as a sound barrier/absorber. It is lighter in mass than either gypsum wallboard, Celotex rigid insulation, or lath & plaster. That means low frequencies will go right through it. Technically, you shouldnt even have any mechanical connection between the interior wall surface & the wall structure. There are resilient lath channels that can be used for this purpose. Its called discontinuous construction & there are many ways to achieve this. There also used to be a product called Acousti-lead (sheeting) that could be used between the wall layers. Sonexs new ProSpec Barrier provides better performance in a similar product & is probably much safer. You dont really need to fill the air space between the studs with insulation. Insulation is mostly porous & light & will affect only the highest frequencies (of which there are relatively very little, and even less that made it into the wall). Keyword(s): Diffusion. Isolation. Mass. Sound absorption comes after all those other things are in place. Exterior & interior noise can produce 3 types of sound problems: (1) multiple reflection of airborne sound within a room, (2) airborne sound transmission through walls, floor/ceilings and openings, (3) structure-borne (impact) sound transmitted primarily through floor/ceilings and from vibration of mechanical equipment and plumbing systems. Highly reflective, hard surfaces, especially flat parallel surfaces can cause airborne sound within a room to build up to annoying levels - even higher than that of the original sound source (ever notice how that table top radio, or the TV set sometimes seems louder after its been on a few minutes & you reach to turn it down?). It is impractical & uneconomical to obtain sound level reduction within a room of much more than 10Db by treating reflective surfaces with sound absorbing materials. For example, a typical ceiling covered with acoustical tile provides a sound level reduction of only 5-7Db, yet the reduction is clearly audible. In others words, dont over do it. All you are going to accomplish is the need to turn up the volume even higher. And with higher volume comes higher distortion.

Ive mentioned this in the architectural section & a few other places in the forum. I dont mean to sound like a know-it-all, but there seems to be a preoccupation with sound absorption through out the forums as opposed to sound dispersion (controlled reflectivity) to control room reflections, frequency response & sound decay. An anechoic chamber may be fine for testing certain performance characteristics of a speaker, but it is NOT a pleasant, nor appropriate place to listen to music. A quiet room is beneficial. But trying to achieve this by simply absorbing sound within the room is the wrong approach. Making the room quiet requires insulation/isolation of the room from the building structure & increasing wall mass, not stuffing it with anechoic wedges or sound absorbing panels. The use of wainscots should look pretty classy but use them to reflect the sound, not absorb it. Put the absorption material in the air space between the wall & the wainscot so that as the sound gets louder & louder, more & more sound gets trapped behind the wainscots (or diffusers) so that the room does not acoustically overload due to extended reverberation times at peak sound levels. What you need to do is try to make the decay more nearly logarithmic, for all frequencies, through out the room, not eliminate it. The reason for using some very large diffusers is because you need to control the reverberation time of the bass as well. The absorption of bass is greater than that of the treble & midrange with large diffusive surfaces. They also help to breakup standing waves. You need to use a combination of diffusive & absorptive surfaces. EXPERIMENT. What you want is a room with a uniform bass-treble reverberation & decay, & uniform frequency response, THROUGH OUT THE ROOM. That being saidits easier said than done.

KH....thanks for the Decca info. How wonderful to see that gem back in production!!! Now my only problem is, do I sprend my Christmas present budget on a lifetime supply of 8045G tubes for my Luxman MB3045's or do I buy a new Decca? lol The Maroon version is what I've been calling Plum. I have several of these. Nice to see they've appreciated. I don't think I paid more than $100 each for mine. They were out of favor at the time. In regards to the Crown gear, I sometimes wonder if the typical listening room coupled with a Klipsch/Crown combination was the culprit (at least partly) for dislike of this setup. Most rooms have a broad midrange peak that would probably help exaggerate that "cold hard grainy" sound. I don't find them all that disturbing. I think everyone got on the bad rap Crown bandwagon back then because of the then "newly discovered" TIM (or Otala) distortion. Matti Otala tested Crown amps himself & found them to be free of TIM under normal operating conditions. Crown was a target of this because TIM seemed to be more prevalent in amps with high amounts of negative feedback (which Crown has). Don't get me wrong, I can never get my Crown stuff to sound like the tubes. The tubes make the K-horns sing & sound glorious. But I also think there are certain colorations & distortions in tube gear that make it "sound better". And speaking of Phase Linear, thats one piece of equipment I consider outright junk. Noisy as all hell. Ditto for Carver's latter amps. I had borrowed a trio of his "1.5t", I think it was called, from my dealer. Was supposed to be "balanced" to sound like a tube amp. I think I had those things in my system all of 5-10 minutes. May I borrow Paul's phrase? "BULL****". Have you ever read Paul Klipsch's dissertation about the "Ultimate LSH Loudspeaker" in the Journal of the Audio Engineering Society? Its hilarious. Only Paul Klipsch could get away with slamming Bob Carver like that. Lately I've been playing music more than listening, so the SS stuff gets the cue. I can't see burning these rare tubes for background music or at parties anymore either. Nobody else really cares anyway, & even if they do, its still probably far better than anything they've heard before.

Peronally, (no offense) I think you're just "hearing" things man! There is no reason for that much difference. On the other hand, its a well known fact that electronics that have been "running" or warmed up for a while tend to sound better. My SS preamp/control center is left on all the time. So is one of the tuners, the center channel power amp & sometimes the L&R channel power amp (by accident). The tube gear I have uses some rather rare/hard to find tubes so I tend not to let them burn any longer than I have to. By the way, there is no comparision between my SS gear & my tube stuff. Tubes win hands down no questions asked. Also this may be of interest to you & other readers. One year back in the 80's I was attending the CES (Consumer Electronics Show). They also had a special "audiophile" section of the show. Klipsch never showed at these type of things for many years. Then what do I see? Klipsch. Klipsch has a large suit at the hotel. And not only that, they are using all Mark Levenson electronics (all SS)& (all $$). The power amps were ML-2 class A 25watt monoblocks which are about the size of a large window air conditioner. Superior results can be obtained with either SS or tubes. Although it is arguably easier to do with tubes. The nature of the beast just doesn't allow you to make as many stupid mistakes.

and shouldn't that read... "always go to other people's funerals, otherwise they'll be going to yours"?

yes, I do. GET RID OF IT (just kidding) checkout startrek.com I think they have one of those "simulators" that can make anything happen.

EJ, Almost forgot..... I take it you are talking about using 12ga Oxygen free copper for the electrical (wall) wiring? If so, I don't think I would waste money on it for that purpose. Plus, better make sure it meets your local building codes. Spend the money on a good isolated regulated power supply/line conditioner instead. Also, I don't think linking (or wraping) 2 of these together is a good idea, whether for the electric power, or for your speakers. This will just create more inductance, which is something you want less of, not more. Going from 12ga to 9ga is not going to produce anything significant in terms of measurable or hearable performance. If you were using a cable that was designed as a 9ga cable, you would be better off, than taking a chance with creating a larger magnetic field around your speaker cable. There's also the time-difference (phase problems) to contend with by strapping 2 cables together. This also may not be audible. But why even bother? Its just more money spent on something with potentially more problems than it solves (the cure is worse than the disease type of thing). artto

EJ, Actually your room dimensions should give you reasonable room response down to 20Hz using the half-room principal. 40Hz without it. You might want to download an Excel spreadheet from this link: http://www.linkwitzlab.com/rooms.htm The file you want is modes.xls. I don't agree with everything this guy has to say but the speadsheet is useful. Your room proportions, while quite generous, and larger than my room, has almost 2.5 times as many room modes "piling up" below 150Hz than I do(26'10"x 18'10" <16'-8.5" on half of the back wall with angled wall/doorway section between it & the 18'10" section> x7.833' ceiling), although the average spacing of the room modes is good, only 0.8Hz. You also have room mode resonances at 60.4Hz & 59.6Hz. BAD. Any electronic hum from amps, electrical noise, grounds,lights etc. will be reinforced. The 60.4Hz is in the height. The 59.6Hz mode is a bit more serious as it has 3 occurances, all in the length direction (28.5'). artto

Correct. The curtains will have very little impact on sound quality. Many years ago, when I first bought my K-horns, we still lived in an apartment (obviously I had future plans for these things). The room was only about 12'x14'. I hung medium weight curtains across the back wall. The curtains had to be "bunched" up...the pleats compressed rather tightly for it to have any impact at all. You could still hear the "ping" between the walls when clapping your hands. There's nothing wrong with a "live" room as long as the reflections are well controled & uniformily dispersed with regards to all frequencies (thats the objective anyway). For what its worth, the reverberation time for a room is generally given at 500Hz, but depends on its intended use & volume (size not loudness). Recording studio listening rooms usually have around 0.4-0.5 second reverberation time. But as I stated above, of particular importance is the avoidance of "piling up" of room resonances which is what diffusers (as opposed to sound absorbers) accomplish so well. You can put the sheetrock over the soundboard. Its more effective if you have an air space 1-2" between the two. Also take a look at Sonex's ProSpec barrier as a layer between the sheetrock & the studs. Bass is going to be the most difficult to handle & that means wall mass to block sound transmission. My room's previous "setup" had a lot of Celotex "tiles" & Sonex panels on the back walls & ceiling areas. I came to the conclusion that the room was overstuffed. Be careful with the sound absorption. Don't over do it. Sonex is somewhat expensive. I bought mine in standard grey, in bulk (a whole box) from a local professional sound contractor. Saved a lot of money. But yes, its worth it. Sonex is unique in that it is an "open-cell" foam. Its acoutically dead. The thicker it is, the lower the frequencies that can be absorbed. Only the geometric structure of the cell(s) is retained. There is not "membrane" between the cell structure as in regular closed cell foam. Sonex is basically 99.9% hollow. They make it in different thicknesses & patterns/shapes for different applications. There are some other companies making something similar now. Just make sure its "open-cell" acoustical foam, not some crap they use for egg cartons or packing material. And yes, thats my room. The flash kind of washed the room's lighting out & makes the panels look like there is less depth between them than there really is. It may be a few weeks or months, but I'll post something that is more representative of what its actually like "in the room". artto

Actually, its not any different. Its just not as prominent the lower you go because the wavelengths are much longer, even longer than the room dimensions most people are listen in. The higher the frequency, the more frequent the occurrence of alternating cancellation & reinforncement. You would be better off just adding a second Heresy bass driver only & leave just one set of mid & high drivers. The bass speaker has the most cone excursion & distortion & determines the overall efficiency of the system. And it would be least affected by the comb filter effect. artto

You really don't want to have 2 center speakers. Two speakers producing the same signal in such close proximity to each other (in a, relatively speaking, small space)produces something called the "comb filter" effect. Various alternating frequencies will be cancelled and exaggerated (producing a "comb" like effect to the acoustic wavefront) due to the time difference between the two speakers. It will create a rather jagged frequency response. artto

Detail of Masonite polycylindrical diffuser/bass damper with offset Sonex suspended between the final interior 1" laminated Celotex sound board & the Masonite. artto

Heres a few pics. The camera flash kind of washed out the dramatic lighting across the curved surfaces. Eventually I'll new pics when the room revisions are finished.

This pic might help. Not sure if its worth a thousand words or not, lol artto

Im not so sure you want to use soundboard as a bunch of flat panels spread around the room. These products, such as Celotex, generally have a tendency to absorb frequencies that you want to retain in a sound room or home theater. They are designed more for noise control in work or commercial/industrial environments. They will basically suck out a lot of the midrange & make the bass sound humpy and bloated. This link has specs for a variety of Soundboard products of the kind you are contemplating. http://www.us.bpb-na.com/wall_panel_products.html . I think you also dont want put a lot of soundboard on the front wall. Klipsch speakers dont seem to like dead sound absorbing surfaces around them. Ive also had a lot problems with dust from the Celotex panels so covering them is probably a good idea. That link above has these panels available ready made with various fabric coverings. Sonex makes some nice materials for acoustical control http://www.mhtc.net/~lowey . Curtains will have more of an visual impact than an acoustical one. Natural & synthetic materials used for curtains are relatively transparent acoustically. Consider the case of a heavy tarp covering some speakers at an outdoor festival. How much does it knock the sound level down? Almost nothing. And they obviously dont have the mass to even begin effecting lower frequencies. What you are really trying to do here is control the distribution of sound so there are no hot or dead spots, at least in the listening area. Consider how the best sounding concert halls in the world are built. Lots of reflective and/or ornate surfaces, curves, angled flat surfaces, etc. to uniformly disperse the sound equally at all frequencies. The smaller the room is, the more difficult this is to do. Under all circumstances, AVOID CONCAVE SURFACES. These will simply focus the sound to a single (very) hot spot. Convex polycylindrical surfaces are ideal. artto

KH, thank you for your kind comments. I honestly didnt think my post would be so well received. I agree with you about the Crown equipment, for the most part. I also used Crown in sound reinforcement in bands in the past & still do occasionally. Sometimes, if needed, Ill pull the PSA2 from the system & use it on a gig (my bands days may be almost over, not sure yet). I use the Crown gear because its clear & reliable. And because the room/system is currently used more for practice/rehearsal/learning songs than for serious listening which would be a major waste burning the tube gear. But, as you said, they can be kind of one dimensional & grainy, especially at lower output levels that easily drive a K-Horn. The PSA2 seems to be somewhat smoother sounding than earlier equipment such as the DC300 or D150s. The newer K series actually sound pretty good & seem to produce a little more powerful & tighter bass. The Crown DL2 is kind of interesting. Its nothing like the earlier IC150 preamps. Its the first (& still the only) piece of equipment I could run any high level source through & not hear any difference compared to running the source directly into the power amps. I know. It seems weird. And it is. But thats the reality. I bought it mostly for its great flexibility in being able to tie everything together. For serious listening with CD, I usually connect the CD player directly to the Luxman tube amps. The CD signal first goes through a bridged center channel circuit (2 in, 3 out with precision pots to fine tune the gain balance) that I made based on the Klipsch Dope From Hope newsletter (Vol 11, No3 & Vol 14, No4). With vinyl I use the Audio Research preamp. Sometimes I just use it as a phono preamp, taking the high level outs through the Crown DL2 (since it seems completely transparent & is noise free). I also use the AR mains out directly to the Luxmans. This yields a more pleasant, but colored sound, albeit with more noise. The AR is a model SP6C. The letter suffix designated revision updates. It was originally a SP6A (the first in the 6 series). The power supply went out & fried a few things. I sent it to AR for repairs & had it upgraded it to a SP6C (current model at the time). Actually, I liked the sound of the early SP6As better. Definitely more colored & sweet, but incredible definition. I havent bothered with ARs more recent stuff, because, as Im sure you know, AR is a master at re-inventing the wheel & charging 5x as much for it. I use the Decca arm only on the Linn. I use the SME on either the Linn or Thorens. The SME III has a detachable arm (as opposed to detachable headshell) (shifts the mass closer to the bearing carrier for better balance & less mass at the cartridge). This makes changing between phono cartridges much easier. Ive used the Decca pickup in both the SME & Decca arms. The Decca arm/cartridge combo is a real pain-in-the-*** to set up. The Decca pickup works really well in the SME arm. The Decca pickup has a clarity & solidity to it that, in my opinion, is unrivaled. The Gold model, I believe has a Van den Hul stylus. The Plum uses an old fashioned conical stylus which has certain advantages, especially with the Decca arm. Ive been looking for a Decca Van den Hul for years now. I dont believe any of the Decca pickups are made anymore. Actually, I was guaranteed first purchase off the initial shipment of US CD players by Sony. That early stuff was absolutely terrible. I waited so long for the promise of digital & was really disappointed (see my contribution to the storyteller contest under K. It should be posted shortly, youll recognize it). The Denon CD player was a major sound improvement over the Revox. Its a pro audio model with pitch control which is something I need as a part-time musician so I dont have to keep re-tuning my instruments. Ive already begun my search for a proper SET amp. What Id really like to get my hands on are the Luxman MB300. There were only 200 pairs of these made in 1984. I noticed a lot people in the forum using 2A3 based amps. I would think that the 300B tube would be the ultimate choice. Since these class A SETs have become all the rage, the cost of these units has gotten astronomical. Im thinking of building my own. Ive downloaded a number of schematics. Any comments on whats the best way to go? I know someone is going to ask, so I might as well tell all now. The musician thing is part-time. Yes I play at the pro level. Mostly rock & blues. Mostly bass, although I also play guitar & some keyboards. My professional background is in architecture. Actually my degree is in landscape architecture with minors in architecture & civil engineering. I switched about half way through & wish I didnt. So please everyone, no landscaping or what kind of bugs are on my trees questions. Im not in landscaping (grrr). artto

Sorry dude. But Klipschorns don't belong in something the size, proportions & construction of a mobile home. Whats the point? artto