JohnA

How have you padded down the 902? I have considered calling UTC and asking about an autoformer with 2 dB steps. I don't want to use the T2A/3916 because it would have the 902 running at 103 dB. I have found 1 dB is audible as sort of a "flavor". It may not be clearly identifiable, but there nonetheless. My brother's constant impedance Type A is a good example. The tweeter circuit runs about 1 dB hotter than my Type AAs (less losses) and his La Scalas are brighter sounding. I might not notice until I hear music I know. I want to keep the forward, "in the room" sound La Scalas have.

A capacitor is 2 plates in parallel, so it is not a direct short. Based on the capacitance there is a frequency where the charge on one plate can influence the other one and the cap begins to conduct. The smaller the capacitance the higher the frequency. That is why the 0.01 cap Gil recommended works. It is only effective well above audio frequencies, where you have a problem. It is small similar to cable capacitance so the amp should not care. Watch for excessive heat, though, in case it goes into an oscillation (not likely). You can use your second terminals for the cap, if you want. It shouldn't matter which pair you use. Tha correct connection is from + to -. Shorting plugs in unused inputs can reduce noise, too.

Shawn, I always thought the 902s were rated at 35 watts, but 15 is correct. Tom Brennan says the 902/802/806 drivers on 511Bs will handle a 1st order crossover at 500 Hz nicely. So, I'm going to use a 1st order at 650, an L-pad to drop the 902 from 106 to 104 dB and a parallel notch filter at 200 Hz to suck out the mid-bass hump I hear and you showed. I should get a nice looking impedance curve and a really flat FR.

How do I size the power ratings of L-pad resistors? I need to knock down the output of a pair of Altec 902-8Bs from 106 to 104 to try a 2-way La Scala. An L-pad seems like the best way to deal with just 2 dB, but I don't want them to burn up.

Leo, Crossovers don't work the way you think. The amp driving the tweeter of your RF-7s sees an increasing impedance as frequency drops. It NEVER see no load on the output terminals. The resistor you added may or may not cause harm, but it is not needed. The crossover adds the impedance at falling frequencies so the the power at those frequencies follows the path of least resistance to the woofers. The woofer section of the crossover does the same thing in reverse. At the crossover point the impedance of each section is double the driver's impedance, cutting output by half. Since you have 2 drivers at half power the output remains flat (give or take a little for real world variances). As an example, at 700 Hz, the tweeter section in your RF-7s might be 50 ohms, but the woofers at 700 might be 7 ohms. The woofers get, say, 98% of the power and the tweeters get the rest. (Note: no actual calculation was made to create this example; it is for illustration only.)

partsexpress.com and madisound.com

0 and 5 in; 0 is negative. 5 & 2 out; 5 is negative for Al's standard configuration. try 4 and 0 out; 4 negative.

All high efficiency speakers will allow you to hear things like your RFI because of their efficiency. Millivolts are audible through K-horns, Belles and La Scalas that just would not be heard with typical speakers because of the 20 dB higher efficiency. If you have that much problem, you are in a really intense RF field. If it is not sensitive to preamp gain it is most likely in the power amp or power amp section of your equipment. If you remove the speaker wires from the amp do you still hear it?

"I've Got The Music In Me", Thelma Houston and Pressure Cooker, CD from the Sheffield Labs LAB-2 Direct-to-disk session. It's a gold CD pressing, too.

Take a bow, Andy. You did a great Job!

What a bunch of Knobs! Did you see the $485 pair of sound enhancing beech wood knobs? BS!

The best center will be another HII. Nothing else will be close enough. Watch ebay and buy HII components and build/have built another cabinet to make your center. You might also split a pair of HIIs with somebody. One from a pair should cost you $150 to $200.

With a little background in EE, Ray's quote was excellent. The article and Shawn's subsequent sound bite sumary illustrate why Al Klappenberger's crossover networks should be excellent with tube amps. It's also why the stock Klipsch crossovers are of no concern to my Parasound SS amps with a damping factor of more than 800 (Ro < 0.01 ohms). I believe the frequency response changes a speaker inflicts on a tube amp are partly responsible for the "tube sound". The other parts are the even order distortion products and the HF limits of the output transformer making a clipped signal more rounded and therefore less harsh.

Craig, What about your 99D?

LOL! Just my luck!

Odds are this is it.

X is the transition year between the K-55-V and K-55-M. What color are the squawker drivers and what crossover did you get?

I can't hear a difference and I can't see one in the response curves i had run on a pair of Heresies, one with the solder terminal -V and K-77-M and the other with the spring terminal -V and K-77. It isn't supposed to be that way, but these 2 speakers tested no real difference.

Isn't the Parasound Pre/Pro $2500?

"Rockin' the Filmore"! Darned good live performance, especially "Hallelujah, ...." and "I Don't Need No Doctor".

Klipsch made the HPS-4000 systems for John Allen for years. When Klipsch Pro was sold, he hired someone else to do the building pretty quickly due to QC concerns. Almost all of Mr. Paul's patents have run out, so there is little legal issue as long as the copyrights are not violated. I believe I learned this from an e-mail "conversation" I had with Mr. Allen over the bass horn of the 525 aka La Scala. I wanted to replicate his bracing. My brother did not want the braces, so I never got to hear the effect. Mine look too nice to mess with.

What year and crossover?

The Shorthorn system is destined for one of 2 places. My M-I-L loves Big Band music. It was the Rolling Stones of HER youth. I had the idea of building the system for her and giving her some of my BB CDs. It will have the look (except for the cd player) of a system she might have used. Since she is funny about technology and gifts, it's second home will be a corner in my living room to perform the same duties. I believe the current owner might approve. Just thinking about that single 50s K-horn, that would be a juicy find! I just can't think of a place to put it.

You can get that woofer reconed for < $75 at most speaker servicing outfits. It was made by Eminence. There should be a code number on the back of the cone to use ordering the replacement parts. No other upgrades are needed. However, if you want to, .... I'd put rope caulk on the outside of the squawker and tweeter horns. If you are goos with an iron, you can replace the caps with polyethylene film and foil types like Hovlands. Look at Partsexpress.com or madisound.com. Replacing the woofer inductor with an air-core of the same value would help, too.