John Warren

Barium Ferrite.

the last section of the URL given by Dieter discusses the bracing of the rear chamber panels that make up the "V". This modification makes a noticable improvement in the bass response. done properly, it eliminates the mid-bass hangover. it is also irreversible since it requires glue and screws.

if you want Mac find a dealer in your area. they always have used equipment lying around. they will all deal.

I have no clue what "tonal, dynamic or timing" mean (???). Accuracy is a violin sounding like a violin, piano sounding like a piano, etc.

The original Klipschorn was developed around a field coil, stiff paper surround 12" Jensen A12 "Concert Speaker". The prototype horn also contained a front chamber between the woofer and baffle acting as a shunt capacitance. Klipsch's discussions and ballparking assumptions are centered around this configuration. Also, for rear chamber calculations, his throat area was (correctly) based on the area of the transition between the 100Hz and 47Hz flare rates and not on the woofer baffle slot. Half inch plywood is inadequate for this horn. Mid-bass peaks are attenuated by bracing the "V" panels that make up the rear chamber. It requires drilling, screwing and glueing edgewise a 1/2" thick, 3" wide plywood rib down the center of each panel.

most transactions are resonable. but be prepared to get burned, it is inevitable.

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can any of you suggest a supplier for the forever sticky surround goop. I have a driver that has a corrugated paper surround that was coated with the compound. it has a small tear in the surround that I would like to patch.

what do Fostex units costs in Germany?

will the cabinet backs stay glued on or do we pay extra for them falling off?

I did a simple swap out and all I heard was the tweeters. they need to be attenuated. I didn't bother screwing with the network so the T-350s are collecting dust. Maybe I'll post them on ebay and try to get $5000 for the pair!

I'm amazed that the LLC is still even MAKING the Klipschorn. It's big, hard to ship, hard to make, has specific placement requirements and has a significantly limited customer base. Since production will not end (I assume) it will be priced to reflect this. As BoB G mentioned it will have a price increase. I am not surprized given the constraints I listed. I hate to say it but at $6K/pr. it really was a bargain.

looks like a Phenolic diaphragm, you don't want to go there

question- what musical instrument drivers do you use that reproduce 16Hz tones?

saw a case of "chainsaw kickback" on the 14th. Does that count?

electric bass can't reach into the last octave and niether can the LaScala. now if you told be you played pipe organ...

Richard Small would disagree with you.

Should audition before buying. LaScala is an odd one, could be in for a dissapointment.

$500 for 16db, I'd sell my mother for a 6db drop!!!!!!!

Al-- The expression comes from L.L. Beranek's "Acoustics" (McGraw-Hill, 1954). I went from memory screwed up! The proper equation for % 2cd harmonic distortion with I in (Watts/cm. sq.) is 1.73 (F/Fc) SQUARE ROOT Since I is directly related to throat size we see immediately that a larger throat will reduce the second harmonic. The K-400 has 0.9 inch diameter throat (2.29 cm). One acoustic watt at the throat yields a power density of 0.243 W/cm^2. A 2" diameter throat is 0.049 W/cm^2 which is almost 5 times lower power density than a 0.9 in. K-400. Since SQRT<5>= 2.23, the 2" throat reduces 2cd harmonic by 54%. NOT insignificant since 2% mid-band total harmonic distortion is a design goal, 1% or less is were I want to be. If we look at the equation and use Fc=230Hz we can calculate the 2cd harmonic over a range of F's for the 0.9 inch throat K-400 and a 2 inch throat with same Fc (in parenthesis). Remember that anything >3% is noticable distortion! F=4000 14% (6%) both fail F=2000 7% (3%) K55M fails F=1000 4% (2%) K55M fails F= 400 1.5% (0.7%) both pass So based on this model two conclusions can be drawn about the K-400 1. It distorts appreciably above about 1000Hz when played at levels necessary to fill a large room and 2. the Fc for a throat this size is too low. No network mod will cure this.

Compression instability (also termed "air overload distortion"): 2cnd Harmonic distortion caused by the non-linear relationship between pressure and volume of the air in the throat of the horn as it undergoes adiabatic compression and expansion. Mathematically-- %2nd Harmonic distortion = <1.73(F/Fc)I>x10^-2 where: F= driving frequency Fc = cut-off frequency I = throat intensity (watts/sq.cm) So Ed, as you state the speed of sound in air for a given temperature, pressure and humidity is a constant....now that I've explained compression instability can you explain this statment and were it was supposed to take us?