cfelliot

Yes, I started to redo the grills and the it just became a stalled project!

@dtr20 I have your phone # and will call you tomorrow night!

Decorators in raw birch.

Note: Emotiva forum has first dibs, but I will return here if no interest. I have a pair of 1973 Klipsch Cornwalls that I am willing to give away!!! Taker would need to pickup. These are vertical Cornwalls. Vertical mean that the horns are orientated. In the vertical axis. They are also mirror images. Some consider these the best sounding Cornwalls ever made. The woofers are in fine shape, but the horns need to have the diaphragms replaced as they are over 40 years old. The crossovers also need to be re-capped due to age. Bob Crites can provide all parts and do the diaphragm replacements. The cabinets are solid, but need to be re-done. In the late 80’s I did them in Formica, but never really liked it. I’d really like to find someone who would like to restore them and pass the legacy to another generation. PM me! Chuck

My only reason for posting the picture of what WinSpeakerZ showed was because someone asked and I happen to have the software. A ported speaker is a LC tank circuit of sorts. The box volume is the "C", While the port is the "L". The OP is cutting the volume in half. So, either the cross sectional area of the port needs to be / 2 or the length needs to be / 2. Either method produces the same "L". I'd rather reduce the length, if possible, than the diameter in any case! No arguments here, I just wanted to explain why I put the picture up!

I created a fake driver and ran it through WinSpeaker. Row1 is a single driver, Row2 is 2 drivers 2x volume. Looks like the port length is 1/2 for 1 vs 2 drivers keeping same diameter. Note Fb and Q stay same.

Nice Job!

I ended up having to attenuate the horns way down relative to the woofers. The woofers are K28s so I had to wire them in series. They measure as a 4 ohm driver and my amp( pair of Emotiva XPA-1Ls) will not drive a 2 ohm load. Given that the Heresy III(K28) is spec’ed at 99dB(I think it’s a bit lower), the Faital HF140/LTH142 at 109dB and -3dB for series woofers, dropping the autoformer to taps Y-4 dialed in a pretty flat curve using REW. I only have about 25 hrs of runtime so far, so I think there’s still a bit of break-in to go. But, man, do this guys image. Not only great width, but just superb depth! I suspect this is more Al’s crossovers than the horns. The horns themselves have that big open midrange sound that was what I was shooting for. The only thing missing is deep low bass. I always knew this was going to be the case and will be adding a pair of subs for below 80-100Hz.

Still tweaking the crossover horn attenuation with REW. I'll post more in a while.......

Yes, about 100lbs each speaker! The 15 ply euro-ply plywood is heavy! Al, did great work on the crossovers!

Well it took a while but this project is finally complete. As you can see from the picture below the new speakers are sitting on top of my 1973 Cornwalls. The final design took a lot of twists and turns, but the end result was worth the effort on my part and many others. The final design uses K28 woofers, the Faital HF140 w/Horn and a custom extreme slope crossover (800Hz). They are being driven by a solid line of Emotiva electronics XDA-2 -> XSP-1 -> XPA-1L(pair). Source is TOSLink from HTPC. Many thanks to: Bob Crites – Lots of advice on initial design and cutting the motor-board. Al Klappenberger – Crossover design, teaching me more about crossovers than you can imagine and putting up with a lot of stupid questions. Dave – For connecting me with Al. Bob Small – Cabinet work. Wife - Tolerance of my turning the living-room into a lab for 6 months. I am more than happy with the results. I finally have that big open Klipsch mid-range sound the the Heresy and Cornwall just couldn’t do!!! Up next, subs for same! Al's crossovers:

Subs are DIY using NHT1259 drivers. No plate amp - Anthem MCA-20 in eqip rack. Crossover @85Hz via pre.

3 Heresy speakers across the front is awesome:

Yes, the Gen2 can be jailbroken the Gen3 can't!

The K-700 or the K-600 in the original Cornwall are of course below the performance of a bigger mid-range horn, but I find the Heresy III, with the exact same horns as the Cornwall III, a solid performer. In fact I would say that it very much out performs any Heresy before it. A fail? I think not with the Heresy. But with the Cornwall III, I think Klipsch should have used a bigger horn. The physical room is there, but the redesign was well before the Cornscala concept.