John Warren

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that a good one!

any professional masons out there? any of you folks skim coat the concrete foundation of your house? Mine was done years ago (it is done entirely for looks) and it's needs to be scrapped off and reskimmed. I'm thinking of doing it myself using a product called *Quickwall* (from Quickcrete). Anyone even know what the hell I'm talking about?? If so, please share your experience(s).

HDBR-Do you know what Klipsch was using to glue up a Klipschorn in 1982? I have a pair of KDBRs here with glue lines that are brown. the glue is very brittle. some of the glue lines are cracked. these have never seen water. I've gone into the horns and "repaired" the joints with strips of Muslin soaked in Weldwood.

when gluing with hide glue a few things to consider 1. must be fresh, if it isn't the bond strength suffers. 2. end-grain gluing-->for maximum bond strength, warm the ends of each board with a heat gun, apply a thin coat of warm glue with a small paint brush to the each end-grain to be joined and let it diffuse in and dry. On the next day, paint both joints with warm glue, brad nail and then drive screws. the boards should be pre-drilled for screws and the screws *loaded* in one board before glueing. 3. I don't like lumber core plywood for enclosures, I only use veneer core plywood. The ends of veneer core, if cut with a 60 tooth carbide blade do not suck up too much glue. also veneer core holds screws alot better. 4. hide glue has zero resistance to moisture, if it gets wet is comes apart. 5. hide glue has tremendous holding capacity. I have cracked 90° butt-jointed 13-ply veneer core glue joints in the plywood. 6. it is very slow setting, a HUGE asset when building Klipschorns. 7. it is corrosive when wet and can get corrosive if damp weather, use stainless steel screws. 8. it can be purchased in cake form for use in hot pots. when it cools it hardens, can be re-used, smells awful. 9. its been around for 600 years, it must be good.

SJ-I'm starting to think that *Abstract Metallurgy* is some sort of course taught in the marketing classes at university. hell...tungsten carbide is also a "9" on the Mohs scale, but at a density 17 grams/cm^3 it's nearly 1.7X denser then lead...certainly won't do much for the woofer transient behavior. (BTW, if my memory serves me Hafnium Carbide is about the same density as lead and will also hit a "10" on the Mohs scale) This message has been edited by John Warren on 05-22-2002 at 06:56 PM

The Mohs scale is esentially useless as an engineering parameter. Diamond and alumina exhibit very high strength in compression. under tensile loads the strength is described by the Weibull parameter (or modulus) which is the slope of the cumulative probability curve of failure (plotted on a log-log graph) as a funtion of applied tensile load. Materials with high Weibull modulii exhibit near deterministic fracture strength (steel for example), ceramics like alumina exhibit a range of tensile strengths (polycrystalline->very low, single crystal->very high). I would think that as a designer of loudspeakers the only real parameters that make sense are the elastic modulus (determines the speed of sound in the solid) and the density (high density means hard to move quickly, F=M*A). The ratio (density/modulus) defines the specific density. Diamond is vastly superior to alumina when looked at in this analysis. This message has been edited by John Warren on 05-22-2002 at 06:38 PM

Wes, If the *lowest* external location of the *dwelling* (not the gargage for example) is out of the flood zone boundary then you are ok and do not need to disclose that the property is in a flood zone. If you think you are close you need to have a your town map maker superimpose the 100/500 year flood zone elevations onto your certified plot survey. Some mortgage companies want to see a 40' minimum distance from the boundary otherwise they may demand flood insurance, others just want it out of the zone. Another point to consider, you can be out of the flood zone but still have a basement flood because the lowest external location is where the foundation meets the top grade of the property. So the basement can flood but the lowest external elevation is higher than the flood level in the basement. FEMA and mortage companies consider that the *serious* flood risk is when the water reaches the first floor. Under these conditions the insurance liability is significant. To install a high dollar HT in a basement (or to just finish a basement) a detailed hydrological study of both the flood zone and high water table elevations and an instrumented GPS elevation survey of the property should be conducted. Some installers (the good ones) will recommend it. Once these elevation studies are complete the risk associated with flooding can be determined. I would build iff the basement FOOTING is at an elevation equal to the elevation of the simultaneous occurance of both the 50 year high water table AND the 100 year flood elevation. This usually occurs after a heavy snow melt and subsequent heavy spring rain. Very few homes made today meet this rqmnt. Home builders just need to meet the *lowest* external location of the *dwelling* rule to build. They can even build in a FEMA flood zone provided they use fill to raise the lowest external point above the flood zone. When they state that a property is not in a flood zone they are technically correct HOWEVER the basement can flood 3-4' and still be out of the flood zone. Homes can be built to satisfy the criteria I stated above and the big dollar homes in my town ($1.5M+) are exactly that, built up 30+ feet of fill. Many of these homes also have billiard rooms, HT's and libraries in the basements. Water + MDF = oatmeal This message has been edited by John Warren on 05-22-2002 at 01:06 PM

actually that's not want they mean. the 100 and 500 year flood plane elevations mean that there is a 1% chance in 1 and 5 years respectively that you will have a flood that reaches the elevation levels shown on the FEMA flood hazard zone maps. 1% chance in 1 year means that in 3.65 days in each year you could get a 100 year flood and 18.3 days in 5 years for a 500 year flood. I had a 100 year flood a year ago last March and I've only lived in this house for three years.

I'll ask for the hell of it, do you know where 100 and 500 year flood plane elevations are relative to the basement footings?

I'd gladly pay $1250 for these... here's another view...

if the woofers are K33Es and are not damaged and the units are pushed properly into the corners the horns should produce decent LF. if not, look at the bottoms of each unit and examine for water damage (which you also did before you bought them, right?). inspect the outside and inside joints for openings. remove the woofer access door and inspect all seams, wire connects. is the woofer door on tightly or is the mtg holes stripped as usual? buying and old Klipschorn is like buying a house, you have to know what to look for before you buy it.

515B came in two sizes, standard 15" (15 3/16" OD) from 1955-1977 and 16" 1977-1978. the K33E is 15 3/16" OD. Altec 515 revision history here: http://www.soundpractices.com/images/515history.pdf Altec YOM dates here: http://www.soundpractices.com/images/largedriv.pdf This message has been edited by John Warren on 05-01-2002 at 06:06 PM

Tom- WIth the LaScala, the bass output is so minimal the issue is boderline moot. I wouldn't "waste" an Altec 515B in a LaScala cabinet.

quote: well, doesn't EBay have some kind of enforcing authority that can cancel misleading auctions? no quote: I mean, this is a pretty clear case of wrong information given on a product. if someone was waiting for those nice-looking cerametallic cones and doesn't get them, they will be pretty pissed, no? who cares?

c

quote: i will alert the authorities if he doesn't answer. and whom may that be?

The drivers are University. tweeter 4401. mid H600 compression driver?. woofer? enclosure is not familiar design to me, could be DIY. University drivers are clearly marked. The labels look large to me in the blurry photos yet seller doesn't know the manufacturer(?). I'd steer clear, seller is either an idiot or just too lazy to bend over and read them (likely both).

I agree with what you say except for the overheating part. Alnico magnets are superior to ceramic in elevated temperature conditions. Alnico 5 is difficult to demagnetize by high temperature exposure. Curie temp of Alnico 5 = 850°C Curie temp of Ferrite = 450°C For Alnico 5 up to about 1,000 F, changes in magnetization are largely reversible and re-magnetizable, while changes above this are largely structural and not fully reversible or re-magnetizable. Approximately 90% of room temperature magnetization is retained at temperatures of up to 1,000 F. For ferrite up to about 840F, changes in magnetization are largely reversible, while changes between 840F and 1800 F are re-magnetizable. For all Ferrite magnets, the degradation of magnetic properties is essentially linear with temperature. At 350 F, about 75% of room temperature magnetization is retained, and at 550 F, about 50% is retained. This message has been edited by John Warren on 04-24-2002 at 07:02 PM

Stig-Yes, I have the plans. This is an early design circa late 40s. It is a 3-way corner positioned enclosure with (2) 6200 12", (1) cobra-12 mid, (2) 4402 tweeters. Not a real *horn*. The rear waves exhaust into the corner of the room ala "Baronette". The woofer fronts radiate directly into the listening area. It was not a production model. Very large, heavy.

I thought it appropriate to post a few Google quotes regarding this topic- Posted by Bruce Edgar on September 25, 2001 at 18:36:06 In Reply to: Re: Klipschorn Drivers posted by Tom Brennan on September 25, 2001 at 18:01:32: If the throat is 3"x13", the k-33 is ok. If the throat is 6"x13", then you have to use a regular 15" horn driver like Altec 515B, JBL 2220, JBL D-130, D- 140. Bruce Posted by Bruce Edgar (M) on January 16, 2002 at 09:45:12 In Reply to: K-Horn posted by vincolise on January 16, 2002 at 01:00:40: The K-33 driver needs to see a 3"x13" throat to get any bass. The old original plans specified a 6"x13" throat. Klipsch changed to the constricted throat in order to make their cheaper K-33 driver give better bass. the full threads can be found here: http://www.audioasylum.com/forums/HUG/messages/16877.html http://www.audioasylum.com/forums/HUG/messages/21750.html This message has been edited by John Warren on 04-24-2002 at 05:39 AM

The cost of the woofer was *the* reason for the throat change. This message has been edited by John Warren on 04-22-2002 at 07:01 PM

Al- The woofer output is only of interest here, the curve above is a resonable representation of that. But, to address this, I have the anechoic response of the woofer wired directly to the amp without the inductor. I'll post it here and delete the one above. This message has been edited by John Warren on 04-22-2002 at 06:35 PM

Trey- Can you post a few pictures of the "new" Klipschorn tweeter/mid-driver. A few of us need to know these things. TIA, JW