Curious_George

What do you want to attenuate? Mid or tweeter? You can make an “L-Pad” from 2 resistors. It is not as convenient but works great.

Perhaps we are all in between meds...

My point exactly. All the other stuff Robby the Robot brought up is inconsequential.

"Looks" are exactly what I was referring to. Although we will never know, I am certain that the big midrange horn that Klipsch has used on the Cornwall IV is no coincidence and was Bob's concept. I am not taking anything away from Klipsch, but just making an observation. In some cases (groups of people), there seems to be this dogma that DIY speakers cannot sound as good as manufactured speakers from a (good) known brand. I disagree, in today's world with inexpensive free solutions, it is very easy to design and create a great DIY speaker IF you have the technical skills and understanding. Now, as far as sound, if you had 100 people listen to them, you would probably have a good amount who like the gentle slope of the Cornscala vs the Cornwall IV. As you indicated, we all hear sound differently, which is very true.

Not necessarily. It has everything to do with the T/S parameters. An enclosure that is too large or too small will negatively affect the low-end response of a woofer in a box or in/on an infinite baffle.

Looks like Bob Crites was ahead of the curve... His Cornscala concept looks just like the Cornwall IV. Bob must have inspired the Klipsch design team. As a side note, equipment reviews have always amused me. They always seem to use the most esoteric items that most people have never heard of. Maybe it is just me, but 90% of the time the associated equipment list is bizarre and never consistent. It is constantly changing.

Just because a "Loudspeaker" has a 12" wooofer does not mean it will reach low(er) frequencies. The (low-end) frequency response of a loudspeaker enclosure is based on the woofer parameters and the enclosure it is in. The woofer T/S parameters will dictate what volume of enclosure the woofer likes to work in. There are a few woofers that you can upgrade to for the stock Heresy enclosure that you can use in a ported configuration to help extend the low frequency response. The wire and crossover have nothing to do with the Heresy low-end frequency response.

I remember the forum back then. It’s one of the reasons I was absent from the forum for so many years. DIYAudio is one of the worst forums for that behavior. Now, I’ll fire back a reply if needed and try to keep it “not personal”, but if pushed, I could care less about being banned from any forum.

My position is about 12' (speakers are approximately 13' apart) from the speakers and I have not experienced any beaming. As far as I know, no one has complained about any "beaming" from the ZXPC 18x10 or 17x11 horns. Some people are more sensitive to beaming than others.

Why did you sell it?

The newer horn geometry of the ZXPC 18x10 horn may sound better than the EV SM120. It’s a personal preference. In general, 2” drivers have less distortion than 1” drivers, but other factors play into that as well. For a three-way system, the 18x10 horn appears to be a perfect choice due to its flat response from 400 ~ 10kHz, unequalized. I listened to both the K55V and 2200Ph on the 18x10 and both sounded great. I give the 2200Ph the edge though. There is some magic going on between the 18x10 and 2200Ph. The sound is very natural, detailed and dynamic.

Capacitors are used so much in electronic circuitry that it’s hard to dismiss them as “horrible”. A few coupling caps in your preamp / amp are not going to make a difference when there are so many more upstream from recording to post processing, etc. I’ve never been a capacitor-phob, but I do like to use good quality (not boutique) caps when I can. Anyway, I just may have mock-up a para-feed to see how it performs. It’s funny how some topologies although deemed better in a lot of areas, never make it to the mainstream and become popular, while other topologies that may seem less optimum find a popular following. Take solid-state for example, I prefer output stages that are “triples” to anything else. However a good Darlington output stage with modern high gain transistors can sound great and drive just about anything.

These PCB’s are definitely not multiple layer. Just single-sided.

1kHz is best especially if you have your 400Hz high pass filter on to eliminate power supply ripple and other low frequency junk for testing. I test with and without the 400Hz high pass to ensure there is no ripple.

Yep... I don't think I'd be taking anything to W4S or at least their senior tech.

I suspect a lot of people don't know or understand topologies and they buy the equipment and listen to it and enjoy it. In Yogi Berra style lingo "I don't know what I like, but I know what I like".

I have never driven difficult loads with my amps, perhaps that is why I have never had an issue with them. However, what about the hundreds of thousands of amps made by Dynaco, Eico, Heath, etc that were Ultralinear? Ultralinear was well documented with plenty of test data. Although I am a fan of Bob, he always had some real unusual amp designs that only he understood. There was nothing "text book" about his "later" designs that is for sure. His magnetic field amps were a smart design and efficient as far as the power supply was concerned. Actually, some of his first designs (early 70's - 700B/400B) were very similar (read: probably copied) from early RCA transistor manuals. Not that it is a big deal, but just saying. An Ultralinear Amp_Page 2.pdf An Ultralinear Amp_Page 3.pdf An Ultralinear Amp_Page 1.pdf

Maybe he will find "Zen" elsewhere...

I'm surprised the amp is not configured to operate in "Ultralinear Mode". In my opinion, it is the best of triode & pentode operation. I guess they wanted the Crimson to have that vintage pentode sound.

Come on, keep it real.

Anything old is going to leak… even humans. Ha ha.

I see Lii Audio is in Hangzhou, China. I spent many years going there for audio development. Nice town.

I listened to the amp extensively on my system and could easily discern all the material in each song. In other words, you can easily hear each instrument and everything at once. Not all amps are that revealing. The attack and decay of the music is also quite amazing.

How is the amp sounding Rich?

Not sure what RIAA curve it had when made, but I now remember redesigning the phono section for the "contemporary" RIAA curve that is accepted today as "standard".