jnorv

What did you pay at Yardbird? OSH was $2/pound. HD wanted $2.60 Jim N

If you can, you should get the builder to install a double set of studs on the shared wall, with the sheetrock on one side nailed to one set and the sheetrock aon the other side nailed to the other set. Double layers of sheet rock will also help. Care should alos be given to sealing all air paths in the walls. Jnorv

C&S, I put 6 pounds of the OSH duct seal on each of a pair of 511's. 4 punds on the lips (2 on each side) and 1 pound on each side of the "flats" between the front flange and the driver mount. Seems to make the HF cleaner. I am using 802D's on this set. I am comparing them to a pair without damping running 902-8B's. For $25, it seems to be worth the effort. The stuff is so sticky that you just mold it on. I still want to try a pair of sand filled boxes. Maybe next week when the wife goes to Amsterdam. Jim N

You dont necessarily need shielding, but you do need 3 conductors. There is twisted pair, shielded mic cable that is only 3/16 OD. I am sure that there are mini plugs made for this cable diameter. If you want to go unshielded, you could experiment with cat 3 telephone line (2 twisted pair of 24 ga). If you dont pick up any RF noise, you could then upgrade to cat 5 Teflon twisted pair and make up a 3 conductor with one of the twisted pair and one wire stripped from one of the other pairs. Jim N

You could get some 24 ga twisted pair with shield microphone cable and make your own. Parts Express has the Large jacks for this cable http://www.partsexpress.com/pdf/092-155.pdf http://www.partsexpress.com/pe/showdetl.cfm?&User_ID=12066359&St=2165&St2=-74875855&St3=69972615&DS_ID=3&Product_ID=2806&DID=7 Jim N

Parts express sells their version of Dynamat for about $3/pound plus shipping. OSH has Duct Seal for $2/pound. I was thinking of kneeding some lead shot into the Duct Seal to increase it's density. Of course the best way to dampen the metal horns is to build a box around them and pour it full of sand. Did that once with my LS's. worked great. Jim N

Dunlavy wanted about $500 for a pair of shipping boxes for their IV's (180 pounds). Jim N

I have a reference to a Dec 1997 JASA, Vol 6, page 3644 for curve fits to the original 1933 data. Not sure whether this is Audio Society or Acoustics Society. Does any one have online access to these Journals and can check. I have not had time to get to the library yet. Jim N

Dave, Have you ever seen a replot of F-M where the verticle axis is loudness in phons and the curves are equal SPL's, instead of the way they presented it? I have been intending to replot the data but never seem to have the time. Jim N

If you are really interested in this, read up on the end correction for Helmholtz resonators. Jim N

http://antwrp.gsfc.nasa.gov/apod/image/0011/earthlights_dmsp_big.jpg Jim N

I just bought some duct seal at HD. Looks like the discription of the "thumb gum" stuff except it comes in 1 and 5 pound lumps. ~ $3 for a one pound lump. Found it on the internet $90 for 50 pounds. Jim N

This might explain some of the high prices. http://www.westernlabo.co.jp/104.htm Jim N

I firmly believe in shooting rabid dogs. Jim N

Try an HVAC contractor. They use a rigid fiberglass in****ation on duct work. Also, try suspended ceiling installers. I bought several bundles of 1/2 inch compressed fiberglass ceiling panels at my local HD. Must have been a fluke since I have not seen it there since. http://www.jm.com/insulation/products/whispertone/OEM_WWallboard_MEO131.pdf JIm N

Where is DT Hofy when his country calls? Jim N

You could screw a piece of plastic (pc board) oriented verticly to the back edge of the xover board and mount 5 way binding posts in drilled holes. I did this to mine and moved the xover towards the rear of my LS's so that the binding posts hung out past the back, which allowed easier connection for spade lugs. Jim N

The LF cut off is set by the horn flare rate. Making the mouth bigger only smooths out the response. To go lower, you have to decrease the flare rate. Jim N

You add the circular mils. 22 ga is 640 CM times 3=1920. 17 ga is 2050 CM. So it is a little less than 17 ga. A CM table is at http://www.weights-and-measures.com/xamerwiregage.html BTW, How do I add active links? Jim N

How do I check the calibration on my RS SPL meter? At listening levels at which I used to blow out my Thiel's, I only read 90-95 db. Jim N

I use software from True audio. A one octave RTA is free. You can buy higher resolution for up to $100. It is full duplex, but you need a good Mic to use it. http://www.trueaudio.com/index.htm Jim N

I think that B Edgar's horn sub is about $1k buck in particle board. Of course it is the size of a refregerator, but it kicks A. Jim N

djk, do you have a thought for the difference in sound if I invert the LS's and put the additional box on top? Makes it much easier to test. Don't have to lift the LS's and it makes it easier to change drivers. This arrangement is close to 1/2 of an Altec 210. I have a pair of 515B's that should also be a good match for a system like this. Second question. What are your thoughts on going bigger on the volume of the cabinet and retuning to get lower bass response? Must be some kind of trade off. I am a firm believer in the 1st law of Thermodynamics-you can't get something for nothing. I am not using the LS's mid/high drivers. I will use 511's with 802's, mounted on top of the stack. Jim N

I found that the perfect solution to the WAF problem was to buy the house next door and move my system into it. I don't complain about her traveling to exotic places on a regular basis (at least once/month). She doen't complain about the gear that I collect. Jim N

djk, do you have any opinion on the optimum extra size for the "base bin". I plan on building a box that I set the LS's on, so the extra volume can be anything that I like. Using the T/s parameters, it looks like a 7 ft^3 box is about right. Jim N