artto

As far as I'm concerned, that's certainly what you implied (again). So as far as the jackass part goes, "It takes one to know one".

Is this is another one of your insinuating comments KH? I see you really don't have anything better to do.

I've used many kinds of discs. And after burning thousands of CDs I can't honestly say that nowadays one brand works better than another. Most of these discs are coming out of the same OEM manufacturing plants with different brand names (or no name bulk packaged stuff). 5 years ago or so, certain discs seemed to prefer certain CD-RW drives. This no longer appears to be as critical as it was then, or I'd be seeing increased defect rates in certain brands of discs which would definitely show up in the number of returns I get from the sales of these CDs. I currently get 1 to 3 returns per 100. And that number hasn't changed for several years now regardless of which brand I use. I've purchased Microboards discs on sale at Guitar Center for as little as 20 cents (50 disc pack) with rebate.

Food for Thought From the book, Paul Wilbur Klipsch, The LifeThe Legend In Acknowledgements: We are indebted to many a person for their assistance in writing this book. Mike Sanders of Quicksilver Audio, for helping us bring out the best in our Klipsch loudspeakers over the last 15 years. (for those of you who dont know, Quicksilver manufactures tube amps, triode in particular)(no, this is not a plug for Quicksilver). Paul & Mike (Sanders) were hanging out in the Hard Rock Hotel on the eleventh floor at the CES in January 2001. Mike asked Paul what he thought was better for the Klipschorn, tube amps with pentode tubes or tube amps with triodes? He (Paul) stared right at me (Mike), let a moment pass, and very powerfully said What the hell do you need a pentode tube for with a damn Klipschorn when all you need is damn triode tube, for godsakes? Me? I use both SS & triode tubes (generally, not at the same time). The SS gear is on all the time. Its used for more general & practical things such as practicing or learning songs while playing along, parties, background music, etc. The class A triode tube amps are used only for "serious" listening. This is primarily because the power amps I use have a circut design which uses a special driver & output tube which has been out of production for more than 20 years. Fortunately, I have a decent supply of these tubes. However, since these tubes are not only expensive, but also very difficult to come by, I choose to use them only when I'm actually LISTENING to music. Kind of like opening a bottle of fine wine to be enjoyed with a special occasion dinner. I am not as offended by SS as some of the other posters here or elsewhere. Under my present listening room conditions (dedicated acoustically tuned room) SS, for some reason, doesn't seem to bother me as much. Makes me wonder if the crummy room acoustics that most people have to put up with isn't responsible for exaggerating the worst qualities of SS gear in a similar way that Klipschorns have gotten criticized for bad sound when it was really the associated equipment or sources that preceded them that were responsible for the poor sound, both then being further aggravated by poor listening room acoustics. That being said, IMHO, my SS gear doesn't hold a candle my tube stuff. My wife doesn't think so either. Neither does anyone who's listened to my system. Can I live with SS if I had no other options? Of course. The bottom line is, if YOU like it, and YOU are satisfied, don't let ANYONE tell you otherwise. Its your ears, your brain, your preferences, and your money.

Bass player here too (acoustic & electric). 5 string basses can go down B (standard tuning) which is about 30Hz. Drop tuning to B flat or A (piano lowest note) will yield 29Hz & 27Hz respectively. You need adequate string length & gauge to do this (not to mention a strong instrument). I'm sure some of the large percussion instruments can get "down there". On the other hand, I'll leave it up to you to decide if something like Mickey Hart's "The Beast" is a musical instrument (or even "musical" for that matter). All I know is I have Doc Johnson Reference Recording with that thing & at one point it sounds like someone dropped a Mac truck onto the floor of an empty 10 story building from the 10th floor. Playing Ranges of Some Instruments Instrument Lower Limit, Approx. Upper Limit Violin G3(196.0 Hz) E7(2637.0 Hz) Viola C3(130.8 Hz) C6(1046.5 Hz) Cello C2(65.4 Hz) E5(659.3 Hz) Double Bass E1(41.2 Hz) B3(246.9 Hz) Flute C4 (261.6 Hz) C7(2093.0 Hz) Oboe Bb3(116.5 Hz) F6(1396.9 Hz) English Horn Eb3(77.8 Hz) Bb5(932.3 Hz) Clarinet(Bb) D3(146.8 Hz) Bb6(1864.7 Hz) Bass Clarinet(Bb) D2(73.4 Hz) F5(698.5 Hz) Bassoon Bb1(58.3 Hz) Bb5(932.3Hz) Contrabassoon Bb0(29.1Hz) Eb3(155.6 Hz) Horn(double, F & Bb) B1(61.7 Hz) F5(698.5 Hz) Trumpet (Bb) E3(164.8 Hz) Bb5(932.3Hz) Trombone(tenor) E2(82.4 Hz) Bb4(466.2 Hz) Trombone(bass) B1(61.7 Hz) Bb4(466.2 Hz) Timpani F2(87.3 Hz) F4(349.2 Hz) Harp B0(30.9 Hz) G#7(3322.4 Hz) References: Rossing, Science of Sound, p 219, White & White p 280 http://hyperphysics.phy-astr.gsu.edu/hbase/music/orchins.html

Heres what Ive experienced, & let me also say that I agree whole heartedly with tbabbs post. There are any number of factors that can affect the quality of CD-R burning, & therefore its playback. Windows is not exactly what one would call the most stable operating system in the world. Theres always lots of stuff floating around in there, and, unfortunately, you cannot turn everything off. To avoid as many conflicts as possible; 1. Close down all programs except explorer & systray from the close program dialog box. 2. Run only the software you need to copy or burn. 3. DO NOT have any other programs/equipment running. 4. Stay off the internet. Disconnect your broadband connection if you have one. 5. Machine maintenance: hard disk defrag, windows system check (with something like Norton Utilities), check hard disc for errors, shutdown machine & reboot before burning, etc. In my experience, the best results are obtained by first ripping the file from the original CD and then burn the copy. Whether or not you are going to be able to do a direct copy to burn is highly dependent on the software & computer you are using, CD playback drive & the CD burning drive. Even if the playback drive is a faster (say 24x or more) speed drive, does not guarantee that actual the transfer rate (through-put) from drive to drive is good enough. Other factors that Ive found affect the burning process are (some obvious) the speed of the machine, the amount of memory, the kind of memory, how the memory in your machine is allocated (ie: some machines share memory for various things like video while other have additional dedicated memory & processors), the kind & speed of the hard disk, and the original CD or file you are trying to burn. For instance, if you have a file that has a lot of tracks on it (ie: 27), and the disc is being burned edge to edge taking up nearly all the available recording time on the disc, these discs seem to be prone to more errors and/or burn failures, especially if you are burning multiple CDs (either many CDs with different files, or just multiple copies of the same file). Contrary to popular belief, SCSI drives are typically not the best choice of hard drive for this application. SCSI drives tend to eat up a lot of system resources which can affect the burning process because of the aforementioned considerations. They are not recommended by the software manufacturer I use (Sonic Foundry). In my experience, Roxio Easy CD Creator is one of the worst pieces of Windows software ever made. I use it for data backup, but thats it. Nothing with music. Ive mastered dozens of recordings and burned literally thousands of CDs. Some for bands that Ive played in, some for other bands (rock, blues, jazz and American classical banjo). I also record, master & produce live-in-concert performances for a local Chorale 2 or 3 times a year in which Ive had the honor of recording some of their guest artists some from the likes of the Elgin, or Chicago Symphony Orchestra. Main CD burning equipment: Dell Precision Workstation, dual 866 PIII, 1GB dual channel 600Mhz Rambus RAM, dual Maxtor 10,000rpm 60GB hard disks, Lite-On (what ever that is) LTN483S 48x CD drive, Sony CRX140E CD-RW drive, Windows 2000, software; Sonic Foundrys Sound Forge & CD Architect. Ive also heard good things about the Plextor CD-RW drives. I burn at 4x on this machine. 2x on my slower one. Sonic Foundry told me the software is actually optimized to burn at 2x. And, it was not intended as a mass production product. For the Chorale I usually have burn runs totaling 85-150 discs. I can usually burn about 20-25 discs in one session that have 20 or more tracks that nearly fill the entire CD. The fewer the number of tracks and/or the amount of recording time, the more CDs I can burn without failure. And just because the software, at the end of the burning session says all 20 discs completed without failure, does not guarantee all of them are actually defect free. I shut down the machine for a few minutes & reboot after doing a 20-25 disc burn. There also seems to be differences as to how tolerant a CD player will be to these disks. And from what I can tell, it seems to be primarily related to error correction. I had one recording I mastered that would not play (skipped & jitter) on my old Revox CD player (circa 1984?). It played fine on everything else, even a cheap BrandX Walkman from WalMart. The old Revox basically doesnt have much in the way of error correction other than the traditional CIRC computer technique of interleaving. As for MP3, I dont use it. Great convenience (which I dont need), but inferior sound quality. IMO, somewhere between a good tape cassette being played back on a top notch machine, and CD, but definitely falls short of CD, SACD or vinyl. Oops, I take that back. I do have a ton of bootlegged live performances of favorite artists in MP3 downloaded from Napster before they went under. But these are obviously for the merit of collecting music that in all likely hood will never be commercially released. Eventually Ill transfer them to CD.

Rick, is Acetal the same thing as or similar to Acetate? I have a near mint condition portable Meissner disc recording machine that I inherited from my long gone father when I was a kid. He bought it when I was born. I believe it used "slow burn" acetate discs. I still have NOS unopened box of 25 disc recording blanks made by Audiodisc. There's a recording of me woofin on a harmonica when I was 1 or 2 years old around here somewhere. I guess you could say I've been doing the direct-to-disc thing all my life! (LOL)

STAY STRONG MY FRIEND

Long ago, reminiscing, about how one of my friend's system sounded so much better with his old Fischer tube amp, before he bought those early 70's Pioneer receivers is one of the reasons I went back to tube electronics. That early 70's Pioneer sure looked pretty. The sound quality was something else.

YEAH!.....LOL Terry Riley is cool too "A Rainbow In Curved Air". I didn't mention him because he's a little more extreme in the "electronic" part of this kind of music. But Reich is mostly acoustic & so is Adams. Anyways.....always nice to see another twenty-first century minimalist fan! You ever seen any of these guys live?

Try this. Not everyone is "ready" for it. Although this music is over 20 years "old", I'm sure most people would still qualify it as "new". My experience has been that the older & more traditional or conservative you are, the less you will like it. composer Steve Reich My favorite piece: Music For 18 Musicians. A very mezmerizing piece. I have it on vinyl & CD. Don't let it fool you. Its all 100% acoustic although it may at times sound like synthesizers or sampling is employed. ECM 1129-2 (CD) Also, Six Pianos; Music for Mallet Instruments, Voices and Organ. This one does have "electric organ" on Voices and Organ. Deutsche Grammophon 2535 4639 (LP) You might want to also check out composer John Adams. Similar vein, but a little more "traditional" bent for this kind of music (orchestral). WARNING: Don't drive while listening to 18 Musicians, especially on dark roads late at night.

No Kidding

overkill: transitive verb, 1957 "to obliterate (a target) with more nuclear force than required" Merriam Webster Collegiate Dictionary 2001 And believe it or not, that's the only definition of overkill in there! Overkill? Doesn't sound like it applies to anything Klipsch does. Go for it man!

HornEd....have you checked out ProSpec Noise Barrier from Sonex? Its only 1/8" thick & has better sound blocking per weight than lead. Might be just what you need. I wish it was available when I built my room. I may still install it but it will require taking some of the room apart which I don't have time for right now. http://www.mhtc.net/~lowey/Noise%20Barriers.htm

Ed...I've posted a whole S**load of stuff regarding acoustics & room construction in the architectural thread (just in case you haven't looked yet)

Thanks JM. And I (obviously) concur that room acoustics are probably the most overlooked aspect. Especially considering the Klipschorn's design which is so intimately tied to the room. I don't have any shots of the back yet. I just took down one large (4'x8') deflector in the back of the room which looks like the large deflector in roomcorner3.jpg. Instead I'm installing 3 smaller ones turned 90 degrees compared to the ones in roomcorner3.jpg. I'm also changing the method of mounting them to the wall for both visual effect & hopefully the ability to trap a little more stray sound behind them. To briefly describe them: they vary in size 1@ 32"x48" 1@ 32"x38" & 1@ 24"x60". They are staggared at different heights & not spaced equally. Kind of a contemporary look. They will be "center" mounted instead of being secured at the edges. A 2"x8" wood "center post" that is about 2/3 the vertical length of the deflector (so you can't see the support without looking directly behind the deflector) will be secured to the wall & the deflector mounted along its vertical centerline to this vertical center post. Angled Sonex sound absorption material that you would normally use in a room corner or wall/ceiling juncture will be installed on each side of the center post behind the deflector. The edge (sides) of the deflector that curves back toward the wall will be about 2" from the wall so it looks as if the deflectors are floating with no support & hopefully will allow a little more stray sound to enter behind the panel from all sides, not just the bowed sides. New track lighting was just installed to highlight the rear wall & deflector panels. I also added concealed halogen "Aura Light" strips to the 2 turntable racks which highlights the edges of the racks very nicely & provides overhead light directly down on the turntable(s).

What I'd like to know how they are specifying the efficiency/sensitivity specification. There's no mention of wattage or distance. Secondly, assuming they are using standard sensitivity measurements (1w@ 1meter), what the hell does anyone need 2,100 watts of power in a domestic environment on speaker that is supposedly capable of 109Db/watt/meter? According to my calculations, that should produce around 142 decibels which is loud enough to not only instantly & permenantly damage your hearing, its also getting in the range where it may damage internal organs! Seems like the "compensation" thang is eating up a lot of the horsepower. Hell, stack a few Klipschorn or MCM Grand bottoms together & I bet you get the same thing. Thirdly, where's the "stereo"? Maybe 18Hz is not audibly directional. But 250Hz & a lot further down sure as hell is!

Glass has terrible acoustic properties. It is not very rigid (its a liquid actually). Its also terrible for blocking sound. As for long wall or short wall, the best thing to do is try it for yourself. If the back wall behind your head is too close when you are in the "sweet spot" you may prefer the short wall placement. My room has a bit more depth so the "ideal" listening position (which about 2/3 to 3/5 of the way from the front wall) and is not against the back wall where bass sound tends to pile up. And please, don't mention mobilehomeless and me in the same breath. Its my personal and qualified opinion that Kelly doesn't know his *** from a hole in the ground. More on that later.

Randy, the pic was taken as far back as I could get. If I took the picture from the listening position all you would see is the center speaker, even with a very wide-angle lens (20mm). From a listening perspective, I find that very useful, as the main speakers are out of the way in the corner shadows & are for the most part in my peripheral vision. I dont like looking at a bunch of flashing lights, glowing tubes or big speakers in my face when trying to re-create (simulate?) some semblance of a live performance. The furniture was moved out of the way for the pictures, as were all the cables hanging from the equipment stands. The pics were originally submitted to Stereo Review magazine many years ago for publishing. And in order to maintain as little photgraphic distortion as possible, you have to have the film plane parallel & centered to the front wall. The furniture would be blocking much of the room in the pic since I have a large 6 piece sectional sofa in there. I've recently decided that the sofa is soaking up too much sound so I've taken out 2 of the Ottoman's & one seating section. Eventually, I think I'm just going to have 2 or 3 "Executive" style comtemporary leather & steel frame recliners in there. The Belle Klipsch should sound basically the same as a Khorn. Personally, I think its bass is somewhat more susceptible to boom. And of course the midrange horn is shorter with a smaller mouth than the Khorn, but larger than the Cornwall or Heresy. The center speaker should not be able to be heard. If you can hear it, its turned up too high. Ive found that the center speaker, when PROPERLY SETUP, will give the sound more 3 dimensional depth, as well as pin point across-the-stage imaging accuracy (when appropriate of course). Even using an amplifier on the center speaker that has different voicing than the side channel amps can make the center speaker stand out too much.

Guy, unfortunately Klipschorns are not for every room or environment, at least not in terms of achieving optimum performance. Thats why Klipsch made similar speakers with near equal performance that did not have the mandatory 45 degree angle & corner placement. In your room, it seems to me, that the open area on the one side of the which leads downstairs may cause a somewhat lopsided sound, at least in terms of the overall sense of acoustic space (reverberation & reflections of sound). You would definitely have to build a false corner or replace the railing with a wall to use the long wall for the Khorns. No, its not the optimum thing to do. But hey, Paul Klipsch used false corners in his second house. The other problem you have is the room proportions. 16x26 should be fine, but 16x30 starts to get excessively long which may make the system sound bloated at certain bass frequencies. You may want to build false corners for both horns & secure them to the house walls. You could even make them much taller than the Khorns (to cover up that open/railing side of the room). Just make sure the false corners extending above & beyond the Khorns are not vibrating too much as they (just as weak walls can) act as passive radiators affecting the bass response. Making the false corners extend more than 4 from the corner will yield negligible improvement. The long wall is the most desirable to achieve a wide-stage stereo perspective which gives the largest good listening area. However, there seems to always be that sweet-spot. It also allows one to perceive the proper scale of larger music productions such as symphony orchestra. However, many recordings are mixed with far right & far left perspective in mind to sound more stereo on most run-of-the-mill playback systems. This is one of the reasons for using a third, derived center channel. Ive also found that use of an audio imaging control or panorama stereo to mono blend control as some preamps/control centers have is useful to bring the stereo image in from the far left & right sides. It just helps to dial the image in to a more realistic scale & perspective if the recording was not mixed optimally for playback on larger systems. I originally designed & built my room to accommodate the Khorns on the shorter (18.5) wall so I would have more room depth for ambience, as in a concert hall. The curious thing I noticed when I experimented moving the Khorns from the 18.5 wall to the 27 wall was how much the sound opened up. It now seemed as though you were in-the-space with the orchestra, and the perspective was large enough to sound like a real live band was in front of you on things like rock, pop & jazz. And I didnt feel a need to turn the volume up as high to achieve the same impact. Needless to say, I had to open up the other room corner and walls, & reinforce it like the other side.

System/Room Frequency Response. The measurements were taken from the listening position using a McIntosh Real Time Analyzer & calibrated B&K microphone I borrowed from a local dealer. This graph is from the room as shown in the first photo in this post thread. It was taken in 1982. The source test signals used were from the Crown Test Equalization Record (vinyl LP). Playback was performed on a Linn Sondek LP12 turntable, Decca International pickup arm & Decca Maroon phono pickup. Amplification used Audio Research SP6A preamp & Luxman MB3045 triode monoblock power amps. The bass hump at 160Hz is due to the Decca pickup/pickup arm. I suspect the rapid fall-off of frequency response at 16KHz is also due to the Decca Maroon pickup which uses a spherical (conical) stylus. In recent years, Ive decided that the room was over-stuffed with sound absorption materials in the rear of the room and this may also have contributed to the high frequency roll-off. This is one of the reasons for the new acoustical treatments seen in the more recent photos. The 160Hz hump doesnt seem to be audible when using the Decca Maroon in an SME III pickup arm using the medium size damping paddle. The other phono pickup I currently use is a Shure V15 type VxMR which provides much smoother and more extended response. After I complete the current acoustical & architectural revisions Ill re-run the tests both from vinyl & CD.

One more for the road...... 1. Kelly, your friend is right. (email "Mother Theresa" on the other thread) 2. I never did like fraternities 3. Ok, I apologize Randy, The dimension across the top looks like 12' on my crt. Me being an architect, I just figured you couldn't draw right. (we architects tend to just draw a "typical" & label the dimensions accordingly & "DON NOT SCALE DRAWING"). Everything else still stands however. You need some real lessons in acoustics/physics before you start doubting me. Believe me, your setup is not approaching anything yielding optimum performance. It wouldn't surprise me if it sounded somewhat painful to me, even with the tube amps. (and update that analogue front-end!) 4. KH......I've got news for you. I knew I was going to have problems with you after 1 or 2 of your additional posts. As far as I'm concerned....you can blow it out your ***. Was that I rock I saw on top of one of your amps on your homepage? Looks like the refrigerator is next to the right side Cornwall too. And your Linn turntable is affected by (among other things) the "moon phases"? Get a life. Cornwalls were my first Klipsch speakers. And I'd be willing to bet that you were "one of those guys" arguing with me in some stereo store 25 years ago about how bad you thought Klipsch was while I insisted that you needed some really clean amplification, preferably tube, AND a proper acoustical environment to bring the best out of them. Now, some years later, you've finally, partially discovered what I discovered decades ago & you are going to tell me what kind of "compromise" wide-stage 3 channel stereo is?..... as if it were Paul Klispch's personal brainstorm to cover up a major flaw, while you continue to play catch-up with someone who's obviously gone to extends that you probably never dreamed of. And YOU and RANDY are going to tell me, that what I already know, is not possible? I've got news for ya Kelly. You haven't got a clue as to what's possible with the components you're using and the environment you're using them in. I've been there. Same/similar gear....years ago. Seems to me you should be asking more questions instead posting inane criticisms based on your personal theories and trying to cover up it by preceding it with statements like "PWK wasn't stupid". My God Kelly. Everything I have posted on here has been backed up by published documentation. "A picture says a thousand words". I have posted a number of those as well to help explain some of my posts & the documentaion. What have you provided? An opinion. Nothing more. Just an opinion. And as far as I have been able to tell, its a somewhat unqualified one. By the way. Have I told you about the importance of room acoustics, the ultimate component? (well, ok, the recording itself is just as important).

In fact, let me end this right now. We might be all using the same bat (ie: a Louisville Slugger=Klipsch). But I've got news for you. You're not in the same league. Not with me. And certainly not with the likes of Paul Klipsch, or William Snow or Fletcher or Wente or Thuras, etc. (And I thought my ego was big!) Its amazing that guys like you & Randy keep arguing about something you've obviously never had the motivation or opportunity or whatever the reason, to pursue. I figured I could contribute some 25+ years of experience and mistakes with these speakers in the hope that others could share in what I've learned. I guess I'm wrong. Good Bye

Kelly, as a fast response (more to follow later........if I'm still compelled enough to insult you verses just considering the source & forget about it)........ BULL**** ( I knew there was a reason I shouldn't even bother posting anything on here. IGNORANCE IS BLISS , isn't it!)

Great observation fini. It always seems to sound better when I'm facing west (LOL). I was given the "Audio Papers from Klipsch & Associates" by Mrs. Eva Belle Klipsch many years ago. As far as I know, the "Dope From Hope" publications were mostly intended as dealer newsletters/bulletins. One the Klipsch engineers, Gary Gillum (don't know if he's still with Klipsch) sent me a set of them back in the 80's. I have another set that I believe I got from the local dealer. They both contain somethings that the other does not. So I'd start by contacting Klipsch. Many of the documents included in the "Audio Papers" should be available on the web or in the library, especially engineering libraries at a college or university. Randy...use the long wall (17'). 12' apart for 2 K-horns is awfully close. See "Experiences In Stereophony" Audio, July 1955, Paul W. Klipsch & "Wide-Stage Stereo" IRE Transactions On Audio Vol. AU-7, No. 4, July 1959 PWK, also, for starters. With the speakers placed the way they are, your "sweet spot" is only about 7-8' from the K-horns. "The Klipschorn is also intended to be listened to at ranges greater than 3 meters" (Richard Heyser, Best of Audio Vol. IV, fall 1989). By sitting so close you are not getting the full benefit of what the K-horns are producing. And if you're sitting further back, you're still not getting the most benefit from the speaker due the to geometry of the speaker's projection relative to the off-axis listening position. Andy, you might contemplate building some false corners (also covered in a D F H newsletter). Gary Gillum describes a corner wall constructed using a 2x4 frame with half inch plywood on the outside & three-quarter inch plywood on the inside (speaker side). They applied formica for cosmetic purposes. "Negligible improvement will be obtained from extending further than four (4) feet from the corner." Paul Klipsch used these in his "second home". I have a hand drawn diagram, from the man himself, showing the layout of the room. To quote the late, great Richard Heyser once again, "Because the Klipschorn uses the corner and floor of the room as a part of the bass reproduction process, the speakers must be placed in the corners for best reproduction. If the listening room does not have available corners or is very small, then, in my opinion, purchase of a Klipschorn system should not be comtemplated. It simply needs room to sing." (thats why Klipsch makes other speakers like the LaScala or Belle Klipsch or Heresy or RF7's folks). While not pointing the finger at anyone in this thread, I've seen some pretty silly setups other places on this forum (like the guy with the 30'x12' mobile home using K-horns on the long wall & he wonders why they don't sound "right"). Whats the point in putting a Ferrari engine in a 1978 Chevette? It couldn't be EGO now could it?....nah! And Randy, I doubt I'm any better off financially than you are. My room was built 20 years ago. I had hoped to build a new house by now with a bigger & better room. Things having gone the way they have, it may never happen. But, who knows? You should also know that I am somewhat at an advantage. I have a strong background in architecture. By the way...concrete does NOT have very good acoustical properties. Great for blocking sound. But its sound absorption co-efficient is enough to make my ears ring just looking at it.