garyrc

@PrestonTom I've long appreciated your posts, BTW. Was that low test-retest reliability with the same part of the same program material? Do you have info on inter-rater reliability? In the olden days, when my friends and I were shopping for speakers, we (informally) found that our design/brand preferences tended to be associated with where we sat in the orchestra. Brass players and those who sat in front of the brass, liked horn loaded midrange/treble. Percussionists liked fully horn loaded speakers. Violinists liked Bozak 3way all cone type speakers. Most of us appreciated the ample bass and small size of the AR-3A acoustic suspension speaker, but all but one of us couldn't stand the muddy, un-dynamic, slow nature of the bass. The AR3A was reputed to be the flattest, "smoothest" of them all, but that didn't make up for the lack of natural, exciting dynamics and subjectively judged transient response. I find it very disturbing that classically trained musicians were screened out of Toole's tests. The aforementioned orchestra friends and I had a great deal of experience with huge a JBL C55 rear loaded horn enclosure, equipped with 2 - 15 inch 154 woofers and a 375 compression midrange driver with 537-509 horn-lens (golden and wavy!). Our favorite record store (mostly classical) used these to demo records, believe-it-or-not. So, we heard these speakers about 3 times a month for about 6 years, through long afternoons. Once in a while we even bought something! Although these speakers had hardly any deep bass (probably almost nothing below about 50 Hz, best guess), the mid/treble range had incredible, clean but explosive dynamics, and sounded a lot like the orchestra we played in every week-day morning. If I had to choose between flat frequency response and realistic dynamics, I'd choose the dynamics every time.

A very distant cousin of T Rex.

Consumer lines only: Best Jubilee preferrably bi-amped and EQd-- see Chris A's posts Klipschorn AK 4, AK5, (AK6?). La Scala II, III (II and III probably better?) or Belle Klipsch (all need a subwoofer -- in my room, below 60 Hz). Consider a horn loaded subwoofer to preserve tight, clean bass. Forte III Heresy III, IV, probably IV is best, with a subwoofer Top of the Reference or Reference Premiere line. Worst (but still good) All have clear, low distortion midrange and treble, high dynamic range, sensitivity ranging from high to extremely high. Those with horn loaded bass (Jubilee, Klipschorn, La Scala II and III, and Belle Klipsch) also have clean, low distortion bass. There is nothing as clean in the bass as well designed horn loading. All could probably use some EQ, especially a slight midrange cut and some judicious bass boost. In general, they are noted for clarity, openness, high dynamic range as well as good microdynamics, excellent brass and percussion. They may not be as smooth ("flat") in frequency response as some (usually more expensive) "audiophile" speakers, but those same "audiophile" speakers sometimes sound veiled by comparison. Your own ears, in your own room, should be your final judge. Listen with a great variety of program material. Buy with a return privilege.

I can't answer your question, but are your present crossovers Klipsch stock models that were used in the AK4 and the AK5? I thought they had crossovers of 450 and 4500, and very steep ones. Just curious.

Used K-horns would be my choice, if you have corners, or can build artificial corners. If you seal up the backs (research it) they still benefit, and probably need, to be very near, or in, a corner, but can be toed in. With a 1800 cu ft room (yours with an 8 foot ceiling), 50 watts should get you something like 112 dB very clean, unclipped, instantaneous (50 ms to 500 ms) peaks and a good, powerful, average level with Klipschorns, according to http://myhometheater.homestead.com/splcalculator.html. That's when rating the Klipschorn very, very conservatively at a sensitivity of 101 dB/1w/1m; the 105 dB/1w/1m would be in a room, speakers in a corner --- but, essentially, that's how you will listen, so you might have about 4 dB more headroom. Somebody may say that your room is too small for K-horns, but I used to have mine in an even smaller room, and they were great! You need a carpet. With any speaker you might have a problem with a perfectly square room, but you an reduce one dimension by putting a well filled set of bookshelves behind the listeners. Screw it to wall studs. If necessary, build a tuned bass trap for any standing wave you get -- but I think you will be O.K. without it. You will probably have to get the crossovers re-capped. If you are not up to it, Bob Crites (BEC on this forum) does it. Be sure to test the tweeters to make sure they are working. Place an old paper towel or TP roll (without the paper) gently up in front of the tweeter, to separate its sound from the (dominant) midrange horn, and listen through it. Play something with lots of treble (but don't turn up the treble or the overall volume much!). Cymbals, triangle, or orchestra bells are good. IMHO, La Scalas would need a subwoofer below about 60 Hz. If you play vinyl, make sure your C28's refurbisher checks the phono section; the Achilles' Heel of the C28 was one channel dropping out on phono (only), usually the right channel, for some reason. Otherwise, it was a wonderful preamp. Khorns, in my room, would respond well to having the subtle Bass Trim turned up, and the separate Bass Control used for bass-shy CDs. Oh, and welcome!

I heard 4311s at the studio of the Different Fur Trading Company in San Francisco, hooked up to a synthesizer (a Moog, I think), in about 1975 (?) ... I was amazed at the SPL they could get out of them, for a speaker of only moderate sensitivity and relatively low power handling capacity. Later, I was reading one of those "build your own recording studio" articles, which advocated using 4311s, or other similarly sized speakers, which said something like, "Ignore the power handling capacity; good manufacturers are quite conservative in the phc rating." It was about that time that somebody asked PWK what the phc meant, and he said, "Probably not much." I guess it depends in part whether the peaks are 50ms or 500ms. Still ...

I would guess that the JBL would be a little "sweeter," and would never give offense. BUT I would guess the Klipsch would be clearer, more detailed, more dynamic, and with really good recordings would sound more real. AlSO For the same Sound Pressure Level you would get from 100 watts into a Forte III, you would likely need about 300 watts into the L100, and the L100 could conceivably overload, because it is rated for a max of 200 watts. I don't think it would, since, at that level we are talking about very brief peaks. These calculations use a sensitivity rating for the Forte III that is 4 dB lower than the manufacturer's rating, which is about what Stereophile got.

Back when I used reel to reel, I found that some alcohol leaves a residue. I think it depends on what the other 1% with 99% or the other 5% with 95% is. You can compare various brands by putting some drops on a clean piece of glass and letting it dry, then looking for a residue. Swan has some 99% isopropyl. I haven't tested it for residue. I would definitely use 99%, or stronger. There are other tape head cleaners, but some are quite toxic and bad for you and the environment.

I'm disappointed and embarrassed for them. Has McIntosh been sold to some fresh squeezed serpentes syndicate?

Yes, it would be less.

Like the time we came home to Oakland after the Bay Area's Loma Prieta earthquake and found that 3/4 of a tall 70 gallon aquarium had emptied itself on the floor. It hadn't fallen over, just sloshed about 55 gallons of water on the floor. The fish were all huddled at the bottom, keeping a low profile. The carpet was soaked, and a subwoofer was wet (not our "good" one). The place smelled like fish water for few days. Luckily, the main speakers in that room were not floor standing, and the Khorns were in another room, far away from fish tanks. The Monster Cable interconnects I had cursed because they were so tight that they could hardly be pushed in came in handy. An expensive Luxman and an expensive Lexicon were hanging from them.

I remember seeing pictures of your place in Mexico (I think), but there is one thing I don't remember. Is the curved ceiling concave or convex? I'd consider some kind of hemispheric diffusion (probably convex, diffusing in several directions, like mushroom heads aimed into the room) on the walls between the 13 foot high level and the 33 foot ceiling, perhaps just some poly-cylindricals orientated in several directions different than the orientation of those below 13 feet, some made of hardwood, some of something harder (more reflective). I really don't know if random directions of a snaggletooth diffuser would be better or worse than mathematically designed ones. A room the size of yours should sound big, IMO. Mushroom diffusers (no psilocybin involved, but magic nonetheless) OR The Human Condition series of sculptures by Lawrence Sheraton -- so your diffusers will be talked about.

Saw him in an indoor concert in Berkeley in the early '70s. There were a few people standing in the aisles because every seat was taken. The fire marshal arrived and said they would have to go. Cohen said, "Oh they can come up on stage with me." People began to do that, and the fire marshal freaked, indicating that they had to leave, and couldn't lay one foot on stage (which had a huge floor area). Cohen calmly tried to reason with this individual, but reason was evidently not his strong suit. "Stop the concert, or we'll turn off your microphone!" He didn't, and they did. He said, "I don't need that," and sang without it. So, they turned off the lights. Someone, I don't remember who, persuaded us that being totally in the dark was hazardous, in case we had to evacuate suddenly (earthquake?), so the auditorium drained. It was all so Berkeley.

Thanks. I am actually using an AVP, but hadn't thought of using it for reverb. I have now tried increasing the delay on the two surrounds, and this works for both music and movies. For music only, I'm trying adding panorama to the increased delay in the surrounds. It seems o help, too. I'll have to listen for several days and see if I still like it, while watching out for novelty effect. Do you know of any additional things I could try with an AVP?

Good question! l'll look into it.

I had a circuit similar to this in the late 70s. It worked pretty well. I'll keep it in mind. Thanks.

Does anybody know of a reverb/ambience black box with pre-delay and adjustable reverb that I can patch into my two rear channels without going through a computer? The laptop is not always nearby. I'm thinking of one that would go between my pre-pro and the two freestanding power amps going to my two surround speakers. Context: I used to have my Klipschorns and surround Heresy IIs in a very small room, so I got a Lexicon CP1 to add subtle, realistic reverb to the two rear channels (Heresys) ONLY, which were in a loft above and behind the room. I emphasize just a touch of reverb from the rear did the job. I used a pre-delay (to put the first simulated wall encounter about 50 imaginary feet away) and used moderate concert hall style reverb (which a reviewer said should have been labeled "ambience"). After a few days of tweaking, I got it just right. It was quite musical, but unobtrusive. A few years later, we moved. For the last 8 years we have had a combination music room/home theater/library in a 4,264 cu.ft. room, with Audyssey making our sound better than ever, except the room is a little too dead. I never thought I'd need reverb in a room that large. The instruments sound real and beautiful, but the reverberation time is too short. I don't want to change the room treatments or content -- it has wall to wall carpeting and many bookshelves and books. Audyssey is working beautifully, and I'd like to preserve what it does for the front three channels. The Lexicon is long dead (developed noise in one channel that is very noticeable unless I have the reverb turned way too far up, or crank up the input up to the point at which it is in the red zone for peaks in orchestral recordings), and no one wants to repair it, for any amount of money, including Lexicon. It is no longer available new, and originally cost > $1,000. They are on the used market for suspiciously low amounts ($30-$60), and I'm not sure how to know if they've developed noise (the amount in my single channel might not bother a garage band, with constantly loud music, but it drives me nuts on soft classical passages). There are intriguing, much more modern, units around, some quite inexpensive (or even free!) but they all seem to need a computer. Is there any way around this? I'd just like to give it a shot. Here is one that is priced right, has pre-delay and everything I need, but it needs a computer. AD034 EOS2 $60 Any ideas?

Yes, and a level of 85 dB for a "loud" passage (even though some, like Keele, Jr., consider 85 dB "medium level," rather than "loud")* allows for instantaneous peaks 20 dB higher, @105 dB, just as THX and Dolby specified. Theater tests of The Empire Strikes Back at standard level (for THX), from wherever their standard mic positions were, produced brief peaks of 108 db, and 110 dB in the deep bass. How long would the leading edges of these peaks last? At from 2 ms to about 500 ms, it would take quite a large number of peaks quite a while, with all those peaks crammed together cheek by jowl, to add up to a figure of 15 minutes (or so) for 115 dB; if the new standard is consistently 5 dB lower (I haven't found it online), I assume that would be 110 dB for 15 minutes (??). OSHA is looking at Industrial Noise, not music, and looks at "continuous" in the sense the sound from a machine might be continuous (not continuous the way a steady tone would be), i.e., time weighted averages, putting the limit at 110 dB for, say, 15 minutes. Orchestral music is not continuous in the steady tone sense, but may resemble, during loud passages, a time weighted average of machine noise. Rock or electronic music, with sustained electrical guitar tones may require lower levels to be safe. The absolute limit for impulsive or impact noise is 140 dB. This surprises me; I would expect a pulse at this level would cause temporary (or permanent) hearing loss, or ringing in the ears. How loud is a gunshot when it occurs at arms length? I know of a case in which a guy drove through the hills, firing his gun out of the car while drunk. His aim was unreliable, so he shot the mast on the side of the front window. He got his hearing back after several hours. Another thought: A highly distorted signal might reach the "I can't stand it any louder" level at a lower true SPL than an only moderately distorted signal, which might get to that hard to take loudness at a lower SPL than would a signal with hardly any distortion. Loudness, after all, is a perceptual/psychological phenomenon, while SPL is a physical characteristic. *Dope from Hope Vol. 16, No. 1, January 1977

Well, not in your high school, but I would think there would have been nerds back to Galileo, Kepler, Copernicus, Leeuwenhoek, and those dudes ... no ... all the way back to Sumer in 3,500 - 4,000 B.C., where the nerds played with the latest in hi-tech --- the wheel. "I can roll may dad's sun disk farther than you can roll your dad's sun disk!" At least they didn't have their slide rules in holsters, and their pocket protectors in the shirts mom (or grandma) bought them, like our guys did. . At Fremont High, in Oakland, California, there were plenty of nerds in our science club and our orchestra in the late '50s, early '60's. As for stoners, I'm not sure ... if we convert that to "pre-hippie," the Beats fascinated us, even though we were too young to glory in their culture in person. We were well aware of the San Francisco Renaissance and we even had a satire/celebration of it in a production with dancers to a marvelous, long drum solo, carrying the "credits" on long strips of construction paper. One read "Censored by Wailing Waugh." Mr. Waugh was the principal. That credit was absent in the second assembly. We had read "Howl," and could appreciate the line, "I saw the best minds of my generation destroyed by madness ..." We knew one or two cases like that, in which very promising individuals were gobbled up by Moloch the Eater of Children. We knew the Beats tended to use marijuana, peyote, and the worst of the time, Benzedrine, but I never saw any used by my age group until about 1965, well after high school. Starting shortly after graduation were the Kennedy years. He gave us hope; he seemed like an older brother. Little concrete change occurred, but he was encouraging. Several I knew joined the Peace Corps. We heard him speak at the UC Berkeley Colosseum, talking about "the broad view," overcoming differences, and respecting adversaries. We were ready! We marched for Civil Rights, questioned the Military Industrial (thanks for coining the phrase in your farewell warning, Ike!), read Paul Goodman, and then ...

A Dope from Hope said that 115 dB was "too damn loud" for an average level, in a chart by Keele, but that particular label is so PWK that it was probably contributed by him. PWK, in another publication, said something like, "To get the blood-stirring levels of a full symphony orchestra, you need peaks of 115 dB at your ears." He should know, he recorded them repeatedly, and probably measured them. My own measurements, in row 10, approximately confirm this. It has been pointed out more recently that, with what we now know about small room acoustics, we probably don't need that much at home. THX put out a chart that indicated that something like 107 dB in my approx. 4,300 cu ft treated room would "sound like" 115 dB in one of their large theaters. Just in case, calculations indicate that a mere 88 watts into a single Klipschorn will produce 115 in my room, without really trying. If someone wanted to rely (I wouldn't), on the instantaneous reserve power Keele believes a "good" amplifier will provide (very brief peaks "10 dB above average, without clipping") that figure would shrink to about 9 watts through a single Klipschorn. Amazing, no?

Movie industry measurements indicate that an empty theater -- or one with a respectful audience -- hovers (as you say) around 30 dB. Mike Todd banned popcorn in cardboard boxes and drinks with ice during his reserved seat showings of Around the World in 80 Days (1956), because, "They fu___ up the stereo." The dynamic range of his 6 channel magnetic sound was probably the highest of the era.

Note that the SPL levels are in terms of dBA; music SPLs should probably be measured in dBC (or dBZ, if your meter offers that option). C weighting takes (nearly) full account of the bass in the program, whereas A weighting rolls it off and underestimates it ( Z weighting treats all frequencies equally). If an orchestral climax is measured by two SPL meters, side by side, one set for A weighting and one set for C, the one set for C will read higher, because it is counting the bass, but the OSHA tables use A weighting.... cirrusresearch A big bass drum, timpani, or kick drum beat may measured too low by as much as 20 dB/ 25 dB if using A weighting. Kick drum beat characteristics:

According to a calculator, peaks of about 120 dB. As read on an SPL meter, the highest I dared go with my ears in the same room provided 110 dB peaks. But, PWK said that, given the ballistics of a needle meter (like mine) unread peaks can be 13 dB higher.... so 123 dB brief peaks???

... and I pointed out that back when it had superior sonics, there was a "large Persian rug, piano, and better placed, more absorbent couches, plus a dog and cat." In the adjoining dining room (barely visible on the left) there was another thick rug, as there was also in the sun room (also on the left). There was also an entry hall off to the right of the room. The acoustics were very musical and complex. 😊

Welcome to the forum! My K77Fs, K77Ms, T35s(EV equivalents, but without the Klipsch testing), too, have high end sparkle. I like it. At least one other forum member went through the same reversal; his thread is labled "Back to the K77s." If some think it sounds like frying bacon, that's O.K. with me. The brass, in particular, is bright and burnished, and sounds like the brass I have heard in live orchestras. Maybe the CT-125s just need to be turned up a bit. Yes, great fireplace! The house I grew up in had one like that, but a little bigger, with JBL 030s in C34 rear folded horn enclosures, and the acoustics were great! I think the fireplace acted as a diffussor. Phantom center material, including soloists, came right out of the firebox opening. As it stands it is much too bright, and the Realtor's wide angle lens makes it seem bigger than its 16 x 24 feet, but when my parents and I occupied it we had a large Persian rug, piano, and better placed, more absorbent couches, plus a dog and cat. I've tried for years to duplicate the acoustics, but failed, by a little, so far. My parents designed the house, and my father, a master carpenter, built it single handed, except for a little extended family help lifting and placing.