D-MAN

That's good thinking. Much less scary than just hacking the dickens out of a perfectly good pair of cabinets. DM

As far as the math goes, I demo'ed my system for a buddy at 300 watts pegged on the meters. Suprizingly, it isn't painful (loud, yes) as you might expect, it is just to the point of being "uncomfortable for longterm listening". It isn't as loud as one would expect from "300 watts". It's only something like 4 times as loud as one watt (1w [or below], 3w, 30w, 300w). Not as impressive as one might expect. However, for HT, which has uncompressed dynamic capability as well as different purposes than music, you tend to use what you've got to its fullest extent, because the loud (explosions, etc.) parts are loud, and the remainder (which is the bulk) of the movie, etc., is "normal" dynamically speaking. For HT use, you NEED all the dynamic headroom you can get. The larger the amp (and respective power supply), the better. DM

I've had Al's "A"-type and various ES's, and the ES of any flavor is the definitive "hands-down" winner. DM

Make sure to ask for the "pre-owned-by-an-idiot" discount! Let's hope "they" didn't vent the back chamber by drilling "cooling" holes in it, you know, to let out the heat! DM

I would like to mention that the use of a lower-frequency midrange horn in a corner MAY BE sort of a bad idea. Here's why... The lower cutoff of the mid-horn is going to be determined by how far the horn is from the nearest reflecting surfaces. That is because the LF is going to be reinforced by reflections, and the mid isn't due to shorter wavelengths not "fitting" in the space between source and reflector. The normal cutoff ios The use of large (i.e., lowER frequency mid-horns) being discussed are going to introduce their own set of problems when placed in a corner. Something to think about! These issues are typically not in play with the "normal" setup of 4 octaves or more on the corner-style bass horn. DM

Tell Al to leave the fuze and fuse holder out! (It's as if you asked him to pull out his teeth with a pair of pliers or something!) Dana

I typically listen to my music below 1 watt. For HT, I use the full 300 watts. Could even use more (well, maybe). There is a great deal of sonic difference between an orchestra, for instance, and gun shots, explosions, etc. Personally, I think explosions should explode. DM

One problem I noted on using the "stock" version of the Edgar Tractrix was that it had a much wider dispersion characteristic than my "normal" 90x40's, which I found hard to control. The soundstage therefore became indeterminate, the opposite of what the coax BMS driver can do in my "other" horns. However, the tonality was exceptional. If somebody finds the "right" horns, let me know! DM

Ah-ha! I went the other way - extend the coverage of the bass horn. Our ideas are directly opposed, yet we choose the same gear to do it! That ought to say something about the BMS driver! Dana

Colin, I think your completely wrong on that. After all, they are NOT Klipschorns! They are not copies and they are not modified Klipschorns, are they?! Can't be a copy because: 1) different plans were used and required to complete the project; none were from Klipsch. 2) So what if they "look" like Klipschorns? Idiots say that about my horns, too, which should be abundantly clear to anyone with a smidgeon of sense that they are 2 entirely different things! I think they should absolutely NOT say anything about being Klipschorns! BTW, the label DOES say exactly that, doesn't it?! It does a humorous tip-of-the-hat to PWK in its layout. I like it alot. But I'm not really kidding about signing them. Sign your work! Dana

I particularily like the label! Nice touch. Don't forget to sign them (100 years from now, when your decendents take them to "Antique Roadshow", that signature will be important)! Provenance, you know. DM

Maron's right - fidelity is still fidelity, "cross-dressing" or not. My opinion of the state of general consumer-grade electronics is that almost (I SAID ALMOST) all of it is crap. Remember this simple idiom: "If it's BLACK on the outside, it's CRAP on the inside!" Given such a case, even the lowliest, cheapest, and most despised of professional PA gear is technically "better", isn't it? At least it was designed and built to do something other than simply "sell to the masses" at Walmart or Sears - where THEY know great audio! Ok, so I'm cynical. DM

The BMS is only rated to 300Hz. I've not heard one below 600. And you certainly don't need to go that low, seems to me. It is really pushing the hardware to cover that territory. The BMS I have is a 2" throat. I haven't hear the smaller versions, but I would question the value of attempting to use a coax on a smaller size throat. DM

Roy makes a good point. There is no horn made that does both low-end and high-end equally well. You have to choose. I am running the BMS 4590 on a P-Audio 4525 (400Hz fc) horn and it works satisfactorily... Attached is the frequency response curves for the BMS in the horn, you will have to look far and wide to do better than this (entirely possible, but very likely more expensive). DM

Source material aside, my opinion is that the PREAMP is the most influential device in the food chain. Tubes pre's seem to be pretty forgiving of impedance variance compared to SS pre's, at least with what I've played with over the years. Second in line is the source device. Warning: [Rant Start] I can't believe the CD players that are used these days by some people with otherwise what I would consider pretty nice systems. Does the word C-R-A-P mean anything? Take a perfectly good system, put a cheap POS CD player on it, and there goes the fidelity - right out the window! So for most, it doesn't matter whether they use tubes or not - they might even prefer "old" sloppy-soft sounding tube gear to take the edge off the cheap CD players they are using! [End Rant] DM

Yeah, but those are HORNS! I would probably agree with you. He's talking about a direct-radiator compared to a bass horn! The physics don't back up his position. So I took it that he was just trying to pick a fight, looking for trouble, fishing for a bite, etc. You know, TROLLING! DM

Yes, it's YOU. Could be one of 2 things, (1) you are insensitive to distortion, or (2) you are simply trolling. DM

Try wavelength = 13200 / Fc (13200 = speed of sound in inches per second) circumference = 1/3 wavelength diameter = circumference / pi which gives diameter in inches. Also MOST designers use 1/3 of a wavelength instead of 1/4 which gives a much smaller mouth size. Keele, Edgar, Leach, etc. formulas are all based on 1/3 wavelength of Fc=circumference of mouth. 1/4 can be a little small and would require very accurate reactance annulling to prevent "peaking". To calculate mouth area the formula is pi * (r * r) or radius-squared where r=radius (1/2 of diameter). DM

It won't go any lower, but it will not suffer from mouth diffraction effects if flush mounted in a wall. Note that placement (radiation angle) won't overrule the horn expansion rate! It is "written in stone" so-to-speak. Best you could do is reinforce the bass that is already there (i.e., corner placement), not add "new" LF frequencies! DM

I second *cough* the *cough* motion! Build a pair of Jubilees, which don't "need" corners but can use them if you've got them! DM

Man, I have no idea, other than to call it a "cast metal bi-radial sectoral horn with a detachable throat adaptor". DM

I would definitely go with a tractrix on the mids. Absolutely, hands down, no-brainer. It has a foot-up on all the horns I have heard so far. Now for upper-frequencies and controlled dispersion characteristics, that is still up in the air... I suppose a smaller horn would help there, we don't need to crossover at 250Hz! Dana

I don't know - I've not heard a 511 that I remember. I tend to ignore small-throated horns, anyway! Dana

"hey D-Man - what the effective inroom sensitivity of La Scala at 55-60Hz?" That is a problem! First, what placement and how far from the walls, etc.? Not as easy to figure (guess) as the Khorn. I'd GUESS maybe 104db or so in a corner, 101 or so in 1/4 space, and 99 or so in 1/2 space. DM

The Klispchorn is a nasty little problem to measure, that's for sure, because the space it's in is required as part of its operation. A room can be measured for its characteristics to null out the response without the speaker, then the speaker is tested and the response adjusted for the room characteristics, etc. The issue is that the Khorn is measured for sensitivity at 3 meters (due to its configuration), and then is "adjusted" mathematically for the 1 meter response. Add to that the complexity of averaging a bandwidth response. An easy estimation of its "expected" sensitivity would be the known 96 db for the K33E woofer @ 1 watt (2.84V). Add +8db for the horn loading and corner placement. That gives about 104 db per bass bin, sans other frequencies. There would be some expectation of variances, but that should be a good ballpark figure. Since the top-end SHOULD be adjusted in operation to be equal or less than the SPL output of the bass bin, they can be safely ignored for the purposes of sensitivity. There would be some losses incurred, of course. DM