Chris A

"...when the model fairly accurately predicts the actual performance...". If the model is far off from tested performance, then I have questions. I have questions. Chris

The reason why I questioned the corner-space parameter in Hornresp is that the simulation that you show really doesn't look like what I remember the tested Jub bass bin performance to look like on the ends of the FR plot. Chris

Greg, Are you accounting for the corner effect in your Hornresp model? Chris Edit: Sorry, I see your parameter for this listed.

Oops, you're right - I looked at my numbers after I got home. My initial guess on path length was 19' but I missed th short lengths on the "switchbacks". Chris

It's 19 feet in length at the centerline, approximately.

Actually, this says that the Khorn has driver delay mismatches that really do need to be corrected. I'm not sure if you are asking about the Khorn design, the article publish date, or the results of the test by Rigma, et al. The article was published in November 1986 and is probably the most famous review written on the Khorn. Richard Heyser was a pioneer in the use of waterfall FFT diagrams and other testing techniques. His untimely death was a great loss to the profession.Chris

Gil, I was doing a Google search and found this thread. Note that, for the record, the 8.4ms delay is between the woofer and the tweeter, not the delay between the signal and receiving microphone. The delay between the midrange and the tweeter is 1.67ms. Sorry for updating this old thread, but this is just in case someone else finds this like I did using Google. I was actually looking for the Heyser article on the Klipschorn: http://forums.klipsch.com/forums/storage/3/1037187/Richard%20C%20Heyser%20KHorn%20Review.pdf Chris

Agreed, but note that it takes a fair bit of gain for folks like me to hear all passages and dynamics of most of those type of recordings - way past the point of being able to hold a casual conversation without using American Sign Language (ASL). At some point, even ASL would get tough due to the probable onset of "hand volume" levels along the way. [] Chris [H]

Thought about Audiogon for the good/expensive stuff and/or Craigslist for miscellaneous stuff? Two percent fee with Audiogon. Zilch with craigslist. You can crosspost here to increase interest. You don't have to box thing up with craigslist or even Audiogon, if you are willing to live with local-area buyers or buyers that can arrange their own shipping. Chris

How do you pronounce Schröder? "Manfred Robert Schröder (12 July 1926 – 28 December 2009) was a German physicist, most known for his contributions to acoustics and computer graphics. He wrote three books and published over 150 articles in his field.[1][2]"

Yours too! [] []

I found the Linkwitz site on "Loudspeaker Design", and remembered the so-called "Schroeder frequency" (I think it is pronounced "shrader" with a long "a"). The formula is: fs = 2000 ( T60 / V )1/2 [Hz, s, m3] Here are the values that I used for my room: V = 152 m^3 T60 = 0.38 (approximate room reverberation time, based on REW-measured results in-room) My listening room's Schroeder frequency turns out to be ~100 Hz. This would explain why I was able to do the in-room measurements below 100 Hz, i.e., in the "sparse mode region" below the Schroeder frequency. Most folks' listening rooms are probably not 152 m^3 in volume, so the Schroeder frequency would be higher than this. If you use the following values for room dimensions, you will see that the typical "sparse mode region" starts at a higher point. Here is a more typical listening room case: W = 20', L = 15', H = 8'; V = 68 m^3; fs = 203 Hz. That would be the approximate break-point frequency below which you could probably get reasonable in-room microphone measurements if you use multiple measuring positions. Just FYI. Chris

The nail-gun king's reputation preceeds him--once again. [] By the way - I'll repeat myself: while I do see the theoretical advantage of avoiding gain-staging the input or output of the Dx38, I have yet to hear anything limiting from this unit in real life (although there has been a lot of angst and subsequent discussions over assumed-but-as-yet-unproven shortcomings). Any other comments that I''ve made here or anywhere else that might appear to detract from personal or product reputation (with the possible exception of SET amplification [6] ) were not intended. I will say that the Jubscala is probably a miraculous improvement over the basic La Scala's sound, I'll also say that there is at least a couple of more tweaks that can improve its performance: 1) stiffening the La Scala bass bin to decrease its resonances, and 2) turning the bass bins around to face a corner (assuming the you have two good corners to put them into)... ...will significantly improve their sound - dramatically so. Chris

Too bad the machine in Waxahachie, Texas (SSCL) didn't come to fruition (...broken promises, broken dreams [8] ) There were some really interesting people involved there. It was a lot of fun as far as it went. [:'(] There was even more promise with SSCL than LHC from a physics standpoint (designed for higher energies but lower luminosity). LHC's superconducting magnets and detector components won't last very long due to their system design choice. But it's good that someone is doing the physics...bravo to the Europeans. Chris

Opah! Mazel tov! Best wishes! [<)] Chris

https://community.klipsch.com/index.php?/topic/93561-la-magic-or-listening-to-la-scalas-backwards/

As a side topic of conversation (not to derail the main topic here...) have you ever thought of taking a La Scala bass bin and turning it around backward to face into a corner? The top of the unit must, of course, be able to be turned 180 degrees from the output of the bass bin to do this. You could even stack two pairs of bins on top to get more net sensitivity with lower distortion.The only issue that I can see is making sure that there isn't anything between the two La Scalas to adversely affect the stereo imaging, since they will be lower than Khorns (assuming that a single pair of La Scalas are used in corners) and thus more susceptible to furniture/electronics racks getting in the way. One could even set up small false corners to increase the corner loading effect without seriously detracting from the decor or the sonic performance (e.g., diffraction, higher-order modes, etc.). La Scalas used in this way could be called "the new Shorthorn". [] I'd bet that they would sound great--and the price is right...Just add your K-402 or K-510 horn with whatever compression driver suites your fancy, with your choice of active or passive crossover (Dx38s go for about $400-$600 on ebay). Wait..wait...I think that I remember someone here (from Maine) that did just that-- and showed pictures of it. Chris

Do tube amps have 100+ dB of SNR? (This is a straight-up question.) Is there a difference between P-P and SETs in this aspect? Maybe this question should go into another thread...Chris

http://www.audioasylum.com/cgi/vt.mpl?f=hug&m=152594 http://www.linkwitzlab.com/frontiers_3.htm

I thought this was a thread on the JubScala...[A] Okay, I guess you have me on that. If you're ever through D/FW, drop in for a critical listening test. My ears aren't 26 years old anymore [] [] Fair enough - note that some folks read only a portion of what is written, then run off and say things like "the Dx38 is a piece of [bs] "Just trying to understand your points, and I believe that I do now. Recently, I've been reading on the demagnetization of typical permanent magnet materials (ferrite, Alnico, ceramic, and neodymium-ferrite-boron) and "flux modulation distortion" of real drivers. This is an area of real interest, since I believe it was that PWK guy who said the following: "...But a small percent of modulation distortion can raise hell with the way it sounds." Taken from 4/89 Speaker Builder Magazine, "A Visit to the Klipsch Kingdom" by Bruce Edgar I much prefer horn-loaded speakers, tweeters through subwoofers (not direct radiators) because of their ~25 dBspl freedom from distortion and their ~15 dBspl increase in output over using the same drivers as direct radiators [...PWK's performance numbers quoted from the same article].

Clearly, the Boston Rally Bass Collection is tuned for this duty...Chris

Mike, 1) Are you taking into account the thresholding of human hearing, effectively reducing the ear's required S/N at very low SPLs? How old are you assuming your critical system listeners to be? 2) Also, are you assuming that most folks are setting up their gain structure in order to get 100% out of the last amplifier stage? It seems to me that if there were a problem with noise floor (...which I don't believe that I've experienced in my listening...), that would be the first response by the user--to adjust the gains to "prevent noise floor audibility". 3) All this is interesting discussion, but I'm still not aware that I'm listening to the postulated problem. I'm listening to Dx38s on a daily basis. What am I missing in detecting the problem? 4) I'd probably prefer to discuss driver FM distortion and IMD before I'd get really excited about my own electronics noise floor, FWIW. We haven't even discussed the noise floor of tube electronics, cables (common mode noise rejection), and TTs in this thread...[:-*] Are we talking about some effect that is 20+ dB away from most currently limiting system performance issues? Chris [:^)]

By the way - this is a very old thread... [] Chris

The Boston Rally Bass Collection Any of these...

I would guess that your Khorns were made on the 110th day of 1993.