I heard the elusive RCA LC-1A's, which I've wanted to hear for more than thirty years. The pair at the 2013 RMAF were in the appropriate prism-edged H.F. Olson (no relation) cabinets, and were powered with custom-made 50 DHT amplifiers. Quite beautiful, really, with the distinctive LC-1A cone with the famous little cones on them, as well as the "twiddler" tweeter. The front end was a suitably exotic turntable with the Frank Schroeder arm, and a Peter Ledermann cartridge. All quite impressive; no CD source or music server on this system, thank you very much. High expectations (I took the center seat in front, looking forward to the legendary RCA "Living Stereo" sound that I knew from many of my favorite recordings).
After all this buildup, what did the RCA LC-1A's sound like?
Ah well. Very tipped-up and out of balance. The bass in the 100~200 Hz range was at least 5 dB down from the 2~5 kHz range, and the treble, although not awful, was fairly ragged and somewhat distorted. The overall impression was very thin and threadbare sound, and high dynamics were not in evidence, despite the 15" driver. The imaging was non-existent, just a blur between the two drivers, with almost no directionality.
Gary Pimm, who visited many of the rooms on that day with me, was appalled. I was surprised, having read about the LC-1A for so many years, and having the utmost respect for H.F. Olson's work on microphones, loudspeakers, and acoustics.
After leaving the room, another show-goer mentioned that a pair of LC-1A's he knew of sounded considerably better than the pair at the show, and speculated that amplifiers might have been defective. Maybe, but I am a little dubious. It's really hard to give that particular spectral tilt to an amplifier; when things go wrong with SET's, they usually sound dull and murky, not thin and tinkly. Unless the output transformers were manufactured with a 200 Hz cutoff (almost no core at all), I can't imagine how any amplifier could sound like that.
Maybe the LC-1A's were not original and some wiseguy built their own cones, getting it completely wrong. I don't know. They certainly didn't sound anything like the FR curves seen in HF Olson's book, which are impressively flat for such an early loudspeaker.
So the RCA LC-1A's were both a surprise and a mystery; was that really the sound of the speaker, or were the amplifiers or phonostage defective? No way of telling. It was the last hours of the show on Sunday, so there was plenty of time to get the demo right.
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Just a brief comment here. Others will have more to say on this.
What you describe conveys the oft below expectations result of what could have been an exceptional listening experience. It is often like this at the European HiFi events.
Your submissions on the new project alone are enabling me to consider positively the suitability of the project for my purposes.
Do you have the project running on a website.
Thanks for your interesting comments and guidance
What you describe conveys the oft below expectations result of what could have been an exceptional listening experience. It is often like this at the European HiFi events.
Your submissions on the new project alone are enabling me to consider positively the suitability of the project for my purposes.
Do you have the project running on a website.
Thanks for your interesting comments and guidance
Hello Badman
I was surprised when I took a look at it. I would be curious to see what a 2450/51/52 waterfall looks like with a Be diaphragm. I think as said previously that the phase plug does play into the mix. That said it looks like that core and other using that phase plug may be a good choice to "upgrade" with the Truextent?? forget the name, Be's.
I know with the 2435's/435Be with their short phase plug you can see some hash in the waterfalls out around 10K or so.
Anyone have a waterfall using any of the cores with the same phase plug??
I was surprised when I took a look at it. I would be curious to see what a 2450/51/52 waterfall looks like with a Be diaphragm. I think as said previously that the phase plug does play into the mix. That said it looks like that core and other using that phase plug may be a good choice to "upgrade" with the Truextent?? forget the name, Be's.
I know with the 2435's/435Be with their short phase plug you can see some hash in the waterfalls out around 10K or so.
Anyone have a waterfall using any of the cores with the same phase plug??
Yes, I heard the Cessaro's; I tracked down the room and heard a few minutes of music before they put on some godawful heavy-metal noise at 110 dB. It did a great job of chasing Gary Pimm and I out of the room, pronto! Gary and I have moderate tinnitus, and that kind of acoustic trauma was the last thing we needed in the middle of an already noisy hifi show.
The Cessaro's, as I recall, had a pretty big MF horn, maybe 25" across, with what looked like a single (or maybe two) 12" Scan-Speak direct-radiator bass driver(s). The dynamic mismatch between the horn and the direct-radiator was very obvious and impossible to ignore, as well as mild degree of FR tipping-up in favor of the horn. Subjectively, the horn sound arrived first, and the bass arrived later ... and a bit short. (The well-known "the check is in the mail" effect.) It wasn't as disastrously out-of-balance as the RCA LC-1A's, in fact the FR was only slightly tipped-up, a balance some prefer (but not me).
A possibility of a horn/direct-radiator dynamic mismatch is exactly the concern I have for the new loudspeaker. The first prototype, which I fined-tuned and spent several days listening to, has a much, much milder version of the dynamic mismatch I heard on the Cessaro's at the show. (Very slight in comparison.) Subjectively, the Altec (GPA) 416 is a better match for mid-sized horn than the driver that Cessaro was using, which didn't sound anything like the horn (think medium-sized Scan-Speak or Vifa dynamics and tone color compared to an Altec 15").
Listening match of the horn and the direct-radiator on the Cessaro points me even more strongly towards a dual-woofer version of the new loudspeaker, possibly with one driver in a closed box (in a Q=0.57 alignment), and the other driver in a low-Q resistive/vented box alignment, covering slightly different frequency ranges (and phase-matched).
Subjectively, going with dual woofers has a greater improvement in headroom and reduction of IM distortion than the theoretical 6 dB (based on what I heard with single versus dual 5.5" Vifas). It also nudges the speaker just over the magical 100 dB/meter/watt line, towards all-horn territory, if not all the way there.
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Here is a smaller model using the 12" alnico Supravox in a back-loaded horn. Same tilted-up response (at least perceptually), no doubt exacerbated by the mic recording it. Cacophonous Jazz instead of "metal":
CESSARO SPEAKERS + ZANDEN AUDIO 300B MONO PSE AMPLIFIER - YouTube
-very good lower spl detail, but with a classic "short-horn's" forward emphasis (..along with the tilted-up response).
It's interesting- we all want the "kick you in the chest" midbass that a good club setup can do, and some are more willing than others to go all the way there- but it's still limited by the room, badly. What factors would you attribute to the sort of bass impact you're looking for? Your findings on the 2226h (which is often considered a very punchy and dynamic speaker) indicate that there's something beyond simply "clean output" you're looking for.
This seems to be an increasingly common occurrence with loudspeakers today.
It's like the old BBC compensation curve #1 (-3db tilt downward from 150 Hz to 7kHz) has been forgotten altogether along with Olive and Toole's more recent analysis on power response in-room.
i thought the Cessaro people built bass horns. direct radiators are toys compared to horns. Why would they forget to bring them? Maybe the room could,t handle the extra energy?
There is a thread at audioasylum talking about the RCA "fill range" you hated. The people posting there actually thought it sounded great.
That's what I like about building my own horn systems. I don't have to deal with other people's fantasies and can stay dead in the middle of my own.
There is a thread at audioasylum talking about the RCA "fill range" you hated. The people posting there actually thought it sounded great.
That's what I like about building my own horn systems. I don't have to deal with other people's fantasies and can stay dead in the middle of my own.
Possible 15 inch driver- dual or single.
Hi Lynn,
Hope all is well with you and you are back to good health.
I note your comments about dynamic mis match between cones and horns.
Well please have a look at this driver...
http://www.precision-devices.com/file-downloads/PD158DataSheet110912.pdf
The Precision Devices 15 inch PD 158.
I initially used it in a three way with a Beyma 15 inch bass driver below 100Hz and the Manger above 1,00Hz, it was and is sublime in that band, the kind of texture and delicacy I got from Volt 2500.4 10 inch or even my all time fav dedicated mid driver the PHL 8 inch M20 2520.
For a 15 inch Pro driver that can handle 500 Watts to a KWatt with Eq boost to make it flat to 35Hz, that is amazing to my ears.
Efficiency is very high, reliability is legendary and power handling almost unlimited...
Now my suggestion would be twin PD 158 's per side, crossed over around 600Hz to 900 Hz then your CD driver / horn combo on top ( with a thick sorbothane pad in between).
That would give you a two system with the cone section up around 103dB per watt...
Hope this helps.
All the best
Derek.
PS I also used my version of Mige0's "swinging speaker mounts" Really great idea and genuinely eliminated all cabinet resonance issues.
Hi Lynn,
Hope all is well with you and you are back to good health.
I note your comments about dynamic mis match between cones and horns.
Well please have a look at this driver...
http://www.precision-devices.com/file-downloads/PD158DataSheet110912.pdf
The Precision Devices 15 inch PD 158.
I initially used it in a three way with a Beyma 15 inch bass driver below 100Hz and the Manger above 1,00Hz, it was and is sublime in that band, the kind of texture and delicacy I got from Volt 2500.4 10 inch or even my all time fav dedicated mid driver the PHL 8 inch M20 2520.
For a 15 inch Pro driver that can handle 500 Watts to a KWatt with Eq boost to make it flat to 35Hz, that is amazing to my ears.
Efficiency is very high, reliability is legendary and power handling almost unlimited...
Now my suggestion would be twin PD 158 's per side, crossed over around 600Hz to 900 Hz then your CD driver / horn combo on top ( with a thick sorbothane pad in between).
That would give you a two system with the cone section up around 103dB per watt...
Hope this helps.
All the best
Derek.
PS I also used my version of Mige0's "swinging speaker mounts" Really great idea and genuinely eliminated all cabinet resonance issues.
Attachments
That's great, like the Mythbuster's slogan "I reject your reality and substitute my own". I couldn't agree more. Considering the depraved and corrupt nature of audio-journalism, you have to follow your own counsel.
Badman refers to the kick-in-the-chest midbass of a band playing in a club, but I'm not really aiming for that. I don't go to jazz clubs or rock concerts that often, and I'm not interested in replicating PA sound in my home. If it does that, fine, but it's not a design goal.
My friend Gary Dahl plays tympani for orchestra; I know what they sound like from a few feet away, and I know what a concert grand piano and a good singer sound like. I like to sit in the 10th-row seats at a concert hall, and get the full impact and vivid tone colors of the orchestra. That's the experience I'm aiming for.
The Karna amplifiers are optimized for peak dynamics, with zero feedback and a very gentle and unobtrusive overload characteristic, like a 1950's vacuum-tube limiter. Although the output is 15 watts in Class A1 at 0.1% distortion, it rises to 30 watts in Class A2 at 3% distortion above that, with immediate recovery from overload (no RC blocking or transistors coming out of saturation). They have the dynamics of 60-watt pentode amp or a 100-watt transistor amp.
I want the new loudspeaker to do the same. No perception of overload, at least with acoustic music. No interest in replicating the rock-concert or dance-club experience, although good dynamics with all kinds of music are welcome.
So I'm not interested in the "slam" that reviewers are always yammering about; the speakers that sound that way are a long ways from my favorites.
Is the piano realistic in scale, presence, and weight? Does the singer sound like a human being, or AutoTune? Does the cello sound like it's made of wood, or plastic?
Very few loudspeakers sound anything like an in-the-room piano, cello, or for that matter, an electric bass. The commercial high-end systems that have the dynamic capability frequently have heavy colorations as well; folded-horn coloration, PA sound, etc. For example, entirely aside from the frequency-balance issue of the Cessaro's, the MF horn has more horn coloration than the AH425's; if you turned the lights out, it sounds like a "horn" speaker.
So I'm not aiming for kick-in-the-chest bass or "slam", although they are nice party tricks to entertain visiting audiophiles. No. I want realism and vividness, and am willing to err on the side of "too much", since most recordings are more drab and colorless than real-life musicians. Part of the reason for all the studio trickery is to draw attention away from the flattened nature of the commercial CD or LP release, which is a pale shadow of the analog tape or high-res PCM master.
Dynamic imbalance was a problem with a lot of the speakers at this show. Many had ribbon tweeters working all the down to 2 kHz, and you could easily hear that the ribbon was badly overloaded in the 2~5 kHz range, with grossly flattened tone-colors and hard, metallic dynamics. (In other word, the tone colors changed quite a bit with playback level, and only in one part of the spectrum. This ruins the artistic intent of the performer, and severely limits the choice of music to "audiophile favorites". No thank you.)
Other speakers had issues with woofer balance; thick, heavy bass, thumping along, but noticeably out of sync with the small-format direct-radiator midrange drivers. One 3-way system had ting-ting ribbon treble, crossed too low to a pair of small carbon-fiber cone midranges, and thump-thump bass from what looked like an expensive 15" subwoofer driver.
Before you think I hated everything at the show, the sound at the Antelope room was really impressive, with the insanely expensive Rubicon DAC/linestage, and ATC SCM100 self-powered loudspeakers. The best PCM digital I've heard to date ... as good as professional-quality DSD128fs, and the ATC's are seriously good loudspeakers, without audiophile affectations. Even Gary Pimm was impressed, which doesn't happen that often.
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This is more or less where I am with my own projects. This is why Imention differrent sector of HiFi. All this nonsense about 110 db plus. This is home theater stuff or club stuff, not music lovers classical authenticity stuff.
I want a violin to sound like a violin both at comparable sound levels and at low levels so I still get the beauty and subtlety. I do not need 5.1. Even 1 speaker can be fabulous on good material for obvious reasons other than needing a stereo or even 3D perspective.
Listening to live fm classical broadcasts witht the 19kHz wall filter with its limitations can beat all the 24/96 chopped up stuff. I know because I can hear the difference.
What I have beats my Quad ELS57 hands down. It is not perfect buit I will not start another speaker construction until I know I can beat it bysome useful margin. I cannot get the Altec drivers here in the UK but I do not need them. I will mod the drivers if I have to to get the sound right.
I can deliver 1000 watts per channel class A so, and I can drive a 2 ohm speaker impedance with alacrity. As I do not need this I run at a low enough quiescent current to cover 110dB of class A . My one off 845 amp gives me the alternative. Long live Sakuma
It seems like you have reached a point of 'diminishing returns'. I am in the same boat. My next speaker - inspired by this thread - may not be better in every way than what I currently have, but I hope that it will provide a different and fun listening experience. Large woofer, wide baffle, low crossover point, high dynamic headroom are taking me off the beaten path of MTM towers. Without offense to the latter of course: here are my current speakers in case anyone is interested: http://www.diyaudio.com/forums/club...ttawa-diy-audio-get-together.html#post2221923. I like them very much and would not trade them for most speakers I hear at audio shows.
I would be interested in learning more about your setup if you don't mind.
Pierre
Thanks very much Lynn for your reports. Sorry the RCA was such a disappointment. Do you think it was a crossover issue? A few years back I heard a GOTO system at a show in Maryland. Impressive system! The legendary GOTO drivers, amazing horns, beautiful craftsmanship, Verdier turntable (my fav), very expensive phono cart and preamp, etc. With all that - came an horribly shrieky tonal balance that would pierce you ears. The crossover was bad. All that expensive technology ruined by a bad crossover. It had been built for the show, and they admitted they got it wrong. Hints of greatness, concealed by a very bright tonal balance. Perhaps it was just as well, I don't want to fall in love with GOTO drivers.
Slam? It's something a lot of people want in a speaker. Not surprising, as slam is (IMO) and artifact of big amps and...... speakers! It's what you get from a good PA system with large, efficient drivers and 100s of watts on tap. The chest thump. That sensation is rare with acoustic instruments, but amplified it can made your insides turn to jelly. As most people's musical experience is almost all from voices and instruments that have passed thru a mic, some amps and a loudspeaker, that's what "sounds right" to them. That can include slam, with the right system. Mid bass slam is a seductive effect, and therefor popular. But it doesn't have a lot to do with acoustic music.
Slam? It's something a lot of people want in a speaker. Not surprising, as slam is (IMO) and artifact of big amps and...... speakers! It's what you get from a good PA system with large, efficient drivers and 100s of watts on tap. The chest thump. That sensation is rare with acoustic instruments, but amplified it can made your insides turn to jelly. As most people's musical experience is almost all from voices and instruments that have passed thru a mic, some amps and a loudspeaker, that's what "sounds right" to them. That can include slam, with the right system. Mid bass slam is a seductive effect, and therefor popular. But it doesn't have a lot to do with acoustic music.
Lynn,
Did you have a chance to walk into Duke's Audiokinesis room? Or the all TAD room with TAD electronics? There were so many systems I didn't get to hear (alas, no time). But the great majority I did hear had a flattened soundstage and a very serious problem in the midbass area (about 100-300Hz) with congestion and confusion going on from a tonality standpoint, especially when you turned the volume to a Slow/C-weighted ~75dB at the listening position.
I saw you there, you were seated near the open air restaurant in the big lobby area, but you seemed busy so I muttered to my colleague..'That's the legendary Lynn Olson...'
Till next year!
Best,
Anand.
Did you have a chance to walk into Duke's Audiokinesis room? Or the all TAD room with TAD electronics? There were so many systems I didn't get to hear (alas, no time). But the great majority I did hear had a flattened soundstage and a very serious problem in the midbass area (about 100-300Hz) with congestion and confusion going on from a tonality standpoint, especially when you turned the volume to a Slow/C-weighted ~75dB at the listening position.
I saw you there, you were seated near the open air restaurant in the big lobby area, but you seemed busy so I muttered to my colleague..'That's the legendary Lynn Olson...'
Till next year!
Best,
Anand.
No slam from a drum kit? Last concert I was second row right on top of the drummer. The clarity and dynamics were awesome.
Rob
Very true..
On the other-hand there is more than a little difference in intensity.
I remember a friend practicing "softly" in his home - and it was too much for me to stay in the same room. I couldn't believe he did that without ear protection.
With out-door venues though you never really get that sense of low freq. "slam". Instead it's just upper-bass to lower-midrange "punch" dependent on distance.