Guinness

Thanks Greg, I did not remember that you tried both drivers. www.usspeaker.com caries BMS drivers. They do not list the 4591 or the 4592ND-MID on their web site. It may be worth contacting them to see if they can get either of these two drivers.

Randy, Consider the BMS 4591 driver also. It's much cheaper. It has a smoother response curve. Although, I have never seen any direct comparison between the two drivers. I have the 4591 and think it is great on Greg's horns. It is a lot larger but, it will fit just fine.

I use the Jabo K55A round horn. I'm thinking of switching to Greg's tractrix.

Beautiful horn Greg! I've been using the BMS 4591 driver for a few years. I let it roll of naturally on the top end and cross the tweeter at 7000 Hz with a second order Butterworth filter. I have not measured it but, it sounds very good there. I tried 6500 and 7500 before settling on 7000. The response curve for the BMS 4592-MID looks nearly identical to the 4591.

There are several two inch drivers that will get low enough if used in a three way system. JBL 2440 JBL 2441 JBL 2482 BMS 4591 If you want to go that low as a (sort of) two way system in a 2 inch driver, try the BMS 4592. It's actually a coaxial design and requires an external crossover to go from the mid to high.

What is the crossover point for the 510 horn with K69? Will it go down to 400Hz?

I'm confused about crossing the woofer to the squawker. Both the Super AA by Dean and the ALK Universal use a first order crossover for the woofer to squawker. The Super AA uses a 2.5 mHy coil for the woofer and a 40 uF cap for the squawker. The ALK uses a 1.3 mHy coil and 48 uF cap. On paper, they both can't be right. I'm sure there's a rational explanation but, I don't know what it is. Can anyone explain? Thanks

freddyi, I think the thread you are looking for is this one.... http://audioheritage.org/vbulletin/showthread.php?t=12697&highlight=selsted I was reading it myself over the last few weeks and thinking of building my own set of Smith's for a tweeter.

I'm curious if anyone has any experience with this alternative round tractrix horn.... http://cgi.ebay.com/Spheric-Wave-Tractrix-Horn-1-400-Hz_W0QQitemZ9718926801QQihZ008QQcategoryZ14980QQcmdZViewItem

What does it mean? What is it about Marantz that doesn't like a low impedance load, more than any other S.S. amp?

The Marantz 2275 is rated at 75 watts per channel, I think. That kind of power will certainly drive most any speaker, let alone the 102 dB efficient RF-7. Should sound great. I have a 2230 that sure sounds good with Cornwalls. Crank it up and enjoy.

The truck probably sounds better. Look at all those tubes in back. Must be push pull. []

Bluesboy, I didn't get the PM. I tried sending you both PM and email. You can contact me also at dm.rains@sbcglobal.net Thanks

Very good to hear Bluesboy. Could you send me a PM to work out the details? Thanks

Stunning! Love the Padauk. Bluesboy, would you consider making those top hat sections available to others? I have 511b horns with JBL 2404's.