Arkytype

Back in March of 1974, PWK wrote a tongue-in-cheek article for the Journal of the Audio Engineering Society. It was a response to various claims made by "experts" regarding loudspeaker design. It later became a Dope from Hope which I've attached. One prevalent premise back then was that the more power a loudspeaker could handle, the lower its distortion would be and the frequency response would be more linear. Now 35 years later, McIntosh Labs offers the ultimate amplifier load bank--oops, I mean loudspeaker in the XRT2K. At a rated sensitivity of 89 dB/1watt @ 1 Meter, the 452 lbs. XRT2K with 110 drivers will output 122 dB @ 2,000 watts input. By comparison, the 175 lbs. Klipschorn with three drivers will output 121 dB with 1/20th the power!! http://www.mcintoshlabs.com/data/brochures/XRT2K.pdf Lee http://www.mcintoshlabs.com/data/brochures/XRT2K.pdf'> Ultimate LSH Loudspeaker.pdf

Joe, From an engineering standpoint the linear tracking arm is a very attractive design. The stylus is perpendicular to the groove at all points on the record. Other than keeping the arm's moving mass low, the designer has to figure out how to advance the arm so that the stylus doesn't lead or lag the groove being played. If LPs all had the same number of grooves per inch, the problem would be easy to solve, however, groove spacing varies with modulation and the arm has to be driven by avariable speed drive system. I owned a B&O Beogram ??? which used a light and shutter mechanism to advance the linear tracking arm. You were limited to using their cartridges which plugged into the end of the arm. The platter was driven by an eddy current "motor" which meant the platter was only connected to the plinth thru the bearing--no belts. With a properly set up pivoting arm, the stylus is perpendicular at only one point. You have tracing distortion at all other points on the record. Lee

Connect the positive/negative terminal of the 9 V battery to the red/black terminal of the tweeter. If the smoke from the tweeter is white, then the diaphragm was moving toward the front before it fried. If the smoke is blue, the polarity was inverted. I've use a neat two-piece device from Rolls for several years for acoustic and electronic phase testing. Unfortunately, it is no longer manufactured. The link is for the manual which includes a schematic for the DIYer. http://www.rolls.com/data/pt102man.pdf Lee

You might want to look at the rack products and accessories from Middle Atlantic Products. Buying knocked down racks makes sense from a shipping cost standpoint. Shipping a six-foot rack via motor freight can cost about as much as the rack itself! If you are handy with woodworking, consider building the rack as a box 19 1/16" wide and as tall as you need. Buy a pair of rack rails which are tapped with 10-32 holes at the length you need. The link shows a few MAP rails offered by Full Compass. http://www.fullcompass.com/brand/MID/Rack-Rails.html Lee

While a fluorescent lamp might work, a neon lamp is what you really need. A neon lamp will transition from off to on and make the strobe markings easier to see instead of the flickering from a fluorescent. Radio Shack has several neon lamps with the necessary built-in dropping resistor. Just take an old extension cord, cut off the female end and solder and tape the neon lamp pigtails. Don't forget to observe correct polarity---just kidding. http://www.radioshack.com/product/index.jsp?productId=2062373&cp=&sr=1&origkw=neon&kw=neon&parentPage=search Lee

I'm five foot thirteeen and my ears at the listening position are about 48 inches above the floor. Guess you could pretend the artists were seated when they were recording. :>)

Mark, So what are you getting when you upgrade from the La Scala to the ne plus ultra Klipschorn other than 20 Hz deeper bass (rated at 33 Hz versus 53 Hz)? The efficiencies, drivers, squawker horns & tweeters for both loudspeaker models are identical. IMHO it has to do with creating a more realistic (ergo believeable) soundstage. The Klipschorn is 15 inches taller than the La Scala. That means the mid and tweeter horns are at your seated ear level, not your kneecaps. Well, maybe mid abdomen! The only "problem" I have with my center channel Belle Klipsch is that the mid and high sound sources are lower than those from the corner horns. This tends to "distort" the soundfield. BTW for those of you considering adding a center channel to your La Scalas, Belle or Klipschorn, I highly recommend an all horn-loaded design. My first pair of Klipschorns (unfinished walnut) was purchased back in 1973 along with a single Cornwall as center channel. Big mistake. Although the Cornwall had deeper bass capability than the horns, the bass distortion compared to the horns was very noticeable. Another consideration is the K-400 horn in the Klipschorn will have fewer cabinet edge diffraction anomalies because it has more "loading" around it compared to the La Scala. Look at the La Scala link and note the amount of wood surrounding the K-400 midrange horn. Now click on the Klipschorn link from that page and note that by looking thru the grill cloth you can see the increased solid surface surrounding the Klipschorn's K-400 horn. Whether there is a direct correlation between "more" or "fewer" diffraction anomalies and "worse" or "better" sound is a subject for objective measurement and subjective listening. http://www.klipsch.com/products/details/la-scala.aspx Here are some interesting links that address the diffraction issue. http://www.trueaudio.com/st_diff1.htm http://www.linkwitzlab.com/faq.htm#Q8 http://www.linkwitzlab.com/diffraction.htm http://www.usenclosure.com/diffraction%20graphs/diffraction-graphs.htm Lee

Damon, While my McIntosh MC502 amp was on my bench getting re-capped, I bought one of the Teac A-L700P amps with the Tripath chip. It is amazingly good. After my McIntosh was back in service, I rigged up an A-B switch which selected either amp's outputs. When amp A was connected to the Klipschorns, amp B was terminated into an 8 ohm load. After carefully matching the gains, and having a second person set the A or B position (so I was unaware of which amp I was listening to) I couldn't tell any difference between the two amps. What is interesting is that while my McIntosh was out of service, I could swear on a stack of "Dope From Hope" that the Teac had deeper, punchier bass. Ah, how easy it is to fool the ear with our perceptions. Once the A-B comparison was in play, I could hear no difference between the amps. There is a great comparison of digital amplifiers at this link. http://www.stereomojo.com/SHOOTOUT2007INTEGRATEDS.htm Since the Teac amp has been discontinued, the best bang for the buck is the shootout winner, the Trends Audio TA-10.1 and this eBay seller has them for sale. The amp doesn't use surfqce mount parts and is a tweaker's dream. http://cgi.ebay.com/Trends-Audio-TA-10-1-Class-T-Stereo-amp-Tripath_W0QQitemZ220157630610QQihZ012QQcategoryZ39783QQssPageNameZWDVWQQrdZ1QQcmdZViewItem Lee

Damon, When I was living in central Arkansas, I had a great listening room (24' X 14' X 9') for my Klipschorns and center Belle. I used about 20 of the RPG BAD panels spaced about three inches apart (V & H) in two horizontal rows on the long rear wall. The side walls were "treated" with foot-square 4" foam wedges and the ceiling with some fiberglass lay in ceiling panels (2' X 4' X 1") purchased from Lowe's with the finished side toward the drywall. I too thought about using Skyline panels on the ceiling, but opted instead for three separate 4' X 4' (two 2' X 4' panels butted together) absorbers mounted with the fiberglass exposed. My thinking was that even with a nine foot ceiling, the Skyline panels would only "see" sound at a grazing angle from the three loudspeakers and wouldn't be that effective as a diffusor. They do make for a sexy (audio-wise, of course) wall treatment. I used a laser pointer (mounted at several angles to cover the nominal 90 X 40 degree dispersion) in each of the three mid range horns and a mirror on the side walls and ceiling to determine the location of the foam and panels. A couple of throw rugs on the tile floor and viola, a great-sounding room. It wasn't bad before the treatment, just a little live for my taste. The BAD panels made the rear wall "disappear" acoustically and the resulting sound field was very neutral to my ears. There were a couple of low frequency modes that needed some diaphragmatic absorption but I moved to NW Arkansas before I could build them. My new home under construction will have a 26-foot wide wall for the horns and Belle with a 24-foot high vaulted ceiling and loft. As I wrote in an earlier post, Daddy Dee and fini heard this setup a couple of years ago. They might want to comment on what they heard. See the first link for info on the RPG BAD panel. Unless you are very patient and are willing to drill several hundred holes in a two-foot-square piece of masonite, the BAD panel is probably not a DIY project! http://www.rpginc.com/products/badpanel/index.htm The BAD panel hole pattern in my panels are different from the design shown in the patent. When I asked RPG about it, they said my panels were an "improvement" and could be mounted in any orientation as opposed to the design shown in the patent which has to be correctly oriented. If you want to view the patent drawings on the U.S. patent office website, you'll need to download a special TIFF viewer available free here. http://www.alternatiff.com/ BAD panel patent # 5,817,992 http://patimg2.uspto.gov/.piw?docid=US005817992&PageNum=0&IDKey=EF02BC575C4F&HomeUrl=http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2%2526Sect2=HITOFF%2526p=1%2526u=%25252Fnetahtml%25252FPTO%25252Fsearch-bool.html%2526r=16%2526f=G%2526l=50%2526co1=AND%2526d=PTXT%2526s1=%252522DAntonio%252522.INNM.%2526OS=IN/%252522DAntonio%252522%2526RS=IN/%252522DAntonio%252522 Here's a link to the Skyline patent. Notice that the commercial RPG Skyline has a 13 X 12 grid with many different cell depths (or lengths). The DIY site below has an ersatz Skyline design using a 12 X 12 grid with only a few cell lengths. If you choose to build your own using anything but balsa wood, keep in mind it will be HEAVY--so mount it on the ceiling using toggle bolts. Skyline patent # 5,401,921 http://patimg1.uspto.gov/.piw?Docid=05401921&homeurl=http%3A%2F%2Fpatft.uspto.gov%2Fnetacgi%2Fnph-Parser%3FSect1%3DPTO2%2526Sect2%3DHITOFF%2526p%3D1%2526u%3D%25252Fnetahtml%25252FPTO%25252Fsearch-bool.html%2526r%3D23%2526f%3DG%2526l%3D50%2526co1%3DAND%2526d%3DPTXT%2526s1%3D%252522DAntonio%252522.INNM.%2526OS%3DIN%2F%252522DAntonio%252522%2526RS%3DIN%2F%252522DAntonio%252522&PageNum=&Rtype=&SectionNum=&idkey=NONE&Input=View+first+page Peter D'Antonio has filed for two patents which expand upon his earlier products. Here are the links: http://aiw1.uspto.gov/.aiw?Docid=20060231331&homeurl=http%3A%2F%2Fappft1.uspto.gov%2Fnetacgi%2Fnph-Parser%3FSect1%3DPTO2%2526Sect2%3DHITOFF%2526p%3D1%2526u%3D%25252Fnetahtml%25252FPTO%25252Fsearch-bool.html%2526r%3D7%2526f%3DG%2526l%3D50%2526co1%3DAND%2526d%3DPG01%2526s1%3D%252522D%252527Antonio%252522.IN.%2526OS%3DIN%2F%252522D'Antonio%252522%2526RS%3DIN%2F%252522D'Antonio%252522&PageNum=&Rtype=&SectionNum=&idkey=697EEF7DFC91 http://aiw1.uspto.gov/.aiw?Docid=20070034448&homeurl=http%3A%2F%2Fappft1.uspto.gov%2Fnetacgi%2Fnph-Parser%3FSect1%3DPTO2%2526Sect2%3DHITOFF%2526p%3D1%2526u%3D%25252Fnetahtml%25252FPTO%25252Fsearch-bool.html%2526r%3D4%2526f%3DG%2526l%3D50%2526co1%3DAND%2526d%3DPG01%2526s1%3D%252522D%252527Antonio%252522.IN.%2526OS%3DIN%2F%252522D'Antonio%252522%2526RS%3DIN%2F%252522D'Antonio%252522&PageNum=&Rtype=&SectionNum=&idkey=2E3DFB7BDBAE Finally, if you want to roll your own RPG diffusor or Skyline-type panels, here's a cool site for the DIYer. One of the overlooked design elements of the RPG-type diffusors is that the well dividers must be as thin as possible. 1/8" masonite (or possibly sheet metal) should be the maximum thickness. http://www.mhsoft.nl/default1.asp Lee

Lee, My 1978 rosewood Klipschorns & Belle are from Honduras. Well, actually they were made in Hope and have Honduran rosewood veneer. :>) Initially, they were built as an oiled finish (KBRWO)? but because the thin veneer dried out in splotches, they were returned to Hope and refinished with clear lacquer. In the late 1960s, Brazil embargoed the export of rosewood unless it was part of a finished product. Of course, the black market immediately drove up the price of rosewood logs already in the country. I've seen one pair of genuine Brazilian rosewood horns that had a black and blood red grain pattern. Stunning. Lee

Mike, I've attached the two Dope From Hope articles re imitations. Lee DFH.pdf

Does anyone remember Yamaha's ear-shaped driver from the early '70s? I think it was mounted in a rectangular box. Making a loudspeaker driver in the shape of the human ear is about as logical as building an eyeball-shaped video display. Lee

Here's page 3 of 3 Hearing vs. Measurement 3 of 3.pdf

Here's page 2 of 3 Hearing vs. Measurement 2 of 3.pdf

Richard C. Heyser wrote over thirty articles for the Audio Engineering Society, IREE including eight written for Audio magazine. I'm posting one of his Audio articles that appeared in the March 1978 issue. Perhaps this paper, Hearing vs. Measurement, will help temper some of the discourse in this thread. I would recommend reading the opening paragraph several times before continuing. Whether you agree with his philosophy or not, he will make you think. If there is interest from the members, I can post the other seven articles that appeared in Audio magazine from June 1977 to May 1979. Any suggestions for posting multiple pages would be welcome. Lee Hearing vs. Measurement 1 of 3.pdf

Neil, Thanks for your post---it is easier to read than mine. Now, everyone save this .pdf to their hard drive for the next time someone needs it. Lee

Fini, I'd rather read the carnage--er discussions from the sidelines. Miz Paula & I will definitely be at the next Klipsch gathering--hope to see your brood there, too. Lee

Here's page 6 of 6. Review page 6 of 6.pdf

Here's page 5 of 6 Review page 5 of 6.pdf

Here's page 4 of 6 Review page 4 of 6.pdf

Here's page 3 of 6 Review page 3 of 6.pdf

Here's page 2 of 6. Review page 2 of 6.pdf

Several forum members have mentioned the late Richard C. Heyser's review of the Klipschorn that appeared in the November 1986 issue of Audio magazine. I was able to locate the review at a university library's reference section. The Audio magazines were bound twelve issues at a time so the text on some of the page edges is a little hard to read. There are six pages so I'll post each one separately for those with dial up. Some of Heyser's measurements and comments will no doubt spark some interesting forum posts. Enjoy. Lee Review page 1 of 6.pdf

Gil, You have a PM.

Garyrc--- 1) Your continuous average sine wave power (CASP) would be 171 watts (just below clipping). That's about 13% above the rated output. Depending upon the program material, the actual peak power would be higher on short transients. 2) I'm not sure if you meant RMS instead of ROMS. A root mean square value as applied to a voltage is derived by taking the square root of the mean of the sum of the squares of a voltage. A true RMS voltmeter will sample the positive and negative values of a waveform, square each sample, add the squared values together, compute the average (or mean) of all the squared values, divide the sum by the number of values squared and finally, taking the square root of the last step. Simple, huh? The primary advantage of a true RMS voltmeter/ammeter is that the result is independent of the shape or symmetry of the waveform and that value can be used to compute the average power or DC heating equivalent of a load. 3) Bob Crites correctly answered this point. Are you looking for this type of 30-ampere receptacle? http://www.internationalconfig.com/icc6.asp?item=L530-R IMHO that's overkill. Be aware that the National Electrical Code requires you to run #10 wire for a 30 ampere circuit. You can't legally use #12 wire which is rated for 20 amperes and connect it to a 30 amp receptacle. Also the circuit breaker has to have a 30 ampere rating as well. I'm installing 20 ampere receptacles in the house I'm building and wiring with # 12 wire. A 20 ampere receptacle has a little more metal where the plug mates compared to the usual 15 ampere receptacle. For you, I'd recommend asking for 20 ampere service with an isolated ground receptacle (usually orange). Bring the ground wire back to the service entrance without tying in to any other ground and connect to the grounding bus bar. That will help system noise and interference from other household appliances. Lee