jnorv

I may be missing something here, but isn't that second plot exactly what a base reflex is suposed to do. At 20 Hz, a half cycle is 25 ms. Just what the program predicts. The port is out of phase with the front of the driver. Jim N

MOre on delay: http://www.trueaudio.com/post_011.htm C&S, I am headed over to SJSU to see if I can find the JAES paper. It may or may not be readable to mere mortals. Jim N

Bad spelling. Vance Dickason, Loudspeader Design Cookbook. Parts Express has them. http://www.partsexpress.com/pe/showdetl.cfm?&User_ID=9829610&St=2451&St2=-39091299&St3=35511662&DS_ID=3&Product_ID=15363&DID=7 Jim

It is the same as a ducted port, just retangular. Most people only rely on the calculated port length to get close to the final value. Dickerson's book explains how to do the final adjustment with a signal generator. Jim

C&S, if you slot load it next to the floor, you can tune it by adjusting the heitght off of the floor. jim N

Gil, very well put. But it does bring up the point that if I am cleaver than I can tune the box/port to accommodate a close wall placement. However if I move the wall, then I have to retune. Jim N

Forget about the wire debate. We have the potential for a whole new knock down drag out fight over the best type of battery to supply thes babies. Just look up the debate on, I think it is the Final battery powered amps. I will admit that I was impressed by the Final amps at eh ChiTown horn fest. Nice and quite.

Ya never know. You might just get lucky. Jim

C&S, What is the actual internal volume that you are going to be using for your 515Cs. I have a pair of Bs with the same T/S parameters that are looking for a home. I have one now in a 10 ft^3 back chamber Karlson that sounds pretty good. Unfortunately I have roots in my sewer line so I have been off the speaker project for a while. I did discover 902s for 511Bs. much better high end than the 802s. If you are an old fart, with limited high end hearing, you can get by without a tweeter. Jim N

I use Thomas and Betts Sta-kon connectors. (www.tnb.com) Their hard copy catalog is much better than the web site. Depending on size they can be had in thicknesses of .040 and .050 inch. Buy them at your local Electrical supply house (the ones the electrical contractors use. I suspect that the high temperature versions are high in Nickel content, which should give good anti oxidation properties. NOt quite gold but close enough. Jim

When I first started listening to my La Scalas a year so back, I too was unhappy with the low end. I traced it to sidewall resonance. I cured it by cutting some large 30 degree wedges and inserting them between the sidewalls and the doghouse. Cut right , they are a drive fit and need no glue. Resonance disappeared. I have also had luck with suspending my downward firing sub from the ceiling. Jim N

For the best start, put the subs where you sit and then move around the room until you find the best response. Then put the subs there. Never tried it with dual subs, but it should get you close. Jim N

Outside flange dimensions are 23 1/4 x 10 1/2. Looks like they would fit into a 21 1/4 x 9 1/4 hole. Depth is 14 inch between the front flange and the horn throat. Jim N

Jazman, Got your email thru the BB. Sent reply with address and phone number. Sunday is fine. I live within 3 blocks of SJSU. Jim

Don't you live up in the East Bay some where. I have a pair that I am not using that I could loan you for a test. I don't want to give them up. I replaced them with homebuilt AK's. Jim N San Jose

The best primer on bridging amps is probably Levinson's amplifier manuels. Try http://www.madrigal.com/i/manuals/No33456OM.pdf A decent amp wil double output from 8 to 4 ohms. A great amp will double to 2 ohms. Only the big Krell will double to .5 ohm. Jim N

Living in the Bay Area, it would take the Super Lotto to just afford the land. I have always wanted to do, what I think, are called French walls. Saw them in some palace in Austia. No hard surface. The walls were covered in fabric. I figured to stuff the cavities with insulation and using something like speaker cloth over it. No reason that you could not build in base traps in the corners (Hemholtz resonators maybe). Jim N

This link to Positive Feedback Mag. was posted on the AA forum. Some of you might not have seen it. When I get big maybe I can have one too. http://www.positive-feedback.com/Issue3/maroom.htm Jim N

This link to Positive Feedback Mag. was posted on the AA forum. Some of you might not have seen it. When I get big maybe I can have one too. http://www.positive-feedback.com/Issue3/maroom.htm Jim N

Do any of you know of a flea powered class A SS amp? I am looking for something to drive the upper end of my horns. I am looking for less than 1-2 watts. My high power 300B is more than enough to drive both the base and the HF, so I figure I only need a 1 watterer. If I were a EE, I would think that I could build one from scratch. The smallest I can find out here is either a Bendini at 25/25 or a Pass at 30/30. Jim N

I live in a 100 year old house with a pier and beam foundation. My sub sets over one of the 4x6 beams but I still seem to drive the floor. Any suggestions on how I calculate the mass of concrete or rock slab that I put under the sub to tame the floor? I have not poked my SPL meter under the sub to get a reading but I ususally listen in the 100 to 105 db room range. Jim

You can use the tone arm run out as a measure of the how much the hole is off center. Also tells you in which direction to move the hole. You could then just use a round file to move the hole over and a record clamp to keep the record in position on the table. I use a Sorbothane record mat which effectively glues the record to the table. Jim N

You can never have enough Coltrane or Mingus. I don't understand why Davis gets all the press. Jim N

http://www.lansingheritage.org/html/jbl/plans/harts.htm http://www.lansingheritage.org/html/altec/plans/1968-plans.htm http://www.audioheritage.org/html/whats-new/site-history.htm Happy hunting. I am sure that T Brennan has a better list. This ought to keep you off the streets and out of trouble for a while. Jim N

OK, you LP nuts, have any of you played with the capacitance of the connection between your TT and Phono input. I have read that this match makes a big difference in quality. Jim N