Live music

January 29, 2018
 by Paul McGowan

Before Infinity Speaker founder Arnie Nudell's unfortunate passing, he and I were working on a new concept in loudspeakers, one based on the idea that it just might be possible to get closer to live orchestral sound levels than we have in the past.

A full orchestra can hit peak levels as high as 120dB. That exceeds the point of hearing damage, which of course was never our intent. And it is not hearing damage we get when in row one of an orchestra because peaks of this magnitude are both brief and rare. Arnie and I had become convinced this was the one quality still missing in speakers.

A few horn-type speakers can manage these extremes but none I know of without colorations (maybe the giant Magicos with their multiple horns? and extremely high price). Might it be possible to achieve these peak extremes without distortion, coloration, mega-amplifiers and bankruptcy court?

That is our challenge. Before his passing, he had made some good progress in a prototype he referred to as the IRS Killer. And it was. What we lacked to complete the design was a midrange driver of a very special kind. And that is now being worked on. It may yet be possible to complete the dream.

If you want to see what Arnie's last prototype speaker system looks like, you can watch this video here. The midrange driver in this amazing reference design is a Bohlender Graebener creation no longer available, but that's ok because it was the prototype's' one shortcoming.

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46 comments on “Live music”

  1. That’s great news!

    Whatsoever I see the main challenge of future speakers to have equal sound at smaller size and to provide flexibility of matching to ones surrounding.

    I always thought the limit in terms of speaker dynamics is not the speaker’s ability, but the meaningfulness and listenability to provide it in normal listening rooms.

    To work on even higher macrodynamics seems a bit like developing street race cars for countries with 120mph speed limit. But I know higher dynamics is never a bad thing, the same with higher speed 😉

    1. Big, accurate sound coming from small speakers violates the laws of Physics.

      To reproduce the SPATIALITY of real instruments, the speaker has to be the same acoustic size and shape of the original sound source. Further, the speaker has to have large surface area to have reasonably low Doppler distortion. For example, I use 6" equivalent tweeters and 8-12" midranges.

      As for the surroundings, if sound quality is the priority, the room should be built to integrate with the speakers. No speakers can fix the inferior acoustics of modern architecture and interior design. My room designs have walls covered with STUFF. Bare walls are bad for the health of your ears and eyes.

      Macrodynamics are accommodated by recordings with real dynamics, as opposed to the universal compression of commercial recordings, and speakers that reproduce the transients accurately. Orchestral musicians exposed to the 120dB peaks DAILY a week do not suffer higher hearing losses than the general population - except for the unfortunates in front of the Trombones.

      Hearing damage comes from machine sounds like subways and jack hammers and distortion of music. If your amps and speakers are operating in a linear region, then the occasional 120dB peaks are not dangerous.

  2. Many many years ago one of the cartoon images in The Absolute Sound, had two guys sitting in front of a full orchestra, their heads were bent back and their hair was back and on guy said to the other "I think they're clipping." Your post the other day about volume for individual types of music touched a chord for me. Too low = irrelevant - Just right = engaging and too loud = distressing. Also these
    levels alter with the mood I'm in. I sit about 3 mtrs back from my speakers and can easily get peaks of 110db (when the wife is out).

  3. I have had several times the chance to listen to the biggest horn loudspeakers from Avantgarde and Acapella in huge demo rooms. However even these rooms were tiny compared to a concert hall designed for 120 dB sound pressure levels. And thus I really couldn’t stand these high volume levels despite the highend speaker quality and the exquisite components of the stereo chain. However I must admit that I never regularity attended ear damaging rock concerts or clubs thus still having most sensible ear drums. Further 120 dB in a normal listening room will never fulfill the requirements of true high fidelity lacking basic requirements of model theory. But the design goal of undistorted 120 for the PS Audio loudspeaker should give enough head room for normal listening levels, Paul.

  4. My dealer has the Magico M3 on permanent demo with the Naim Statement amplifier. I went to a demo and it is a very heavy sound I personally found quite unpleasant.

    I mentioned a few months ago a demo by Pete Thomas. He has designed and installed in Capitol Records' main studios a 4,850wpc active speaker system that can generate 132db with no distortion. They are commercially available at a considerable price. His next level studio monitor that is available as a consumer product goes very loud with almost limitless dynamics and costs about 40%. Using that speaker, he played a drum solo recording that had no compression. It sounded unbelievably real, but he explained that it would destroy most speakers. Recordings of extreme sound are compressed for that reason.

    I would therefore assume that orchestral recordings are compressed to make them listenable, and I have one or two that have less compression and are not very listenable. So I don't see the point of a speaker designed to resolve the original dynamics that have most likely been removed.

    I went to the launch of the large Harbeth M40.2, one of the best monitors available for pro or consumer use and used in studios and homes worldwide. It is designed to be used in a large studio or home on the premise that anything much above 100db on a sustained basis will damage your hearing. So, like the comments above, my issue is that consumers and professionals alike are likely to opt for a speaker that suits their listening space without risking their health.

    1. The issue with high output horn speakers has always been the midrange driver. There are plenty of very high quality HF devices (think TAD in particular). There are plenty of ways to put multiple LF drivers together. As far as I know, there was only one high quality midrange compression driver, the Community M4- 200 Hz to 4 kHz with some equalization. It is no longer built. One Watt was sensitivity was 114 dB, max output 137 dB.

      We designed a theater system around the M4 and installed it in the screen clusters in Muppets 3D theater down in Florida in the late eighties. Dynamic reproduction and clarity was superb with the most demanding material.

      1. This driver you refer to would be great but my experience with horns has always been an unhappy one. Their acoustic amplification characteristics always colored the sound to unacceptable levels for me. But the specs you mention on this driver would be near perfect. A shame it's not made anymore.

        1. I've been a Quad owner since 1973, a couple of Gale GS401 systems, and of course a triamplified set of Hill Plasmatronics. None of them blastingly loud, but all with a fine phase response. I don't think you'd call me a horn guy.

          The nice part about the M4 is that is was run well under its own maximum capabilities and not pushed anywhere near distortion. We were also able to keep any crossover out of the vocal range, which I think essential for any quality speaker system- there just no way a split right in the middle of you highest audio acuity range makes sense to me. Yet 99% of speakers still do it.

          All in all, I was very surprised at the performance. Dynamics and midrange clarity. Not exactly cost effective, but impressive.

      2. My friend Alan Thompson used Community Horns for decades, but switched to the superior Tom Danley Synergy horns. The Danleys are the only horns that sound like music to me across all genres, I have a trio of Unity's.

        Alan's remark was that the point source is clearer than line source arrays, which always have phasing issues in the treble region from inter-driving spacing, parallax and end effect.

        1. Tom Danley does fantastic work indeed.

          And yes, line arrays are easier to rig and pack in a truck. I recently wrote an article on line arrays versus the Grateful Dead's Wall of Sound.

          The Wall was totally impractical. But up close, also magical.

          1. The "Wall of Sound" used columns for guitars and bass strings. The vocal and piano arrays were cylindrical sections, which also have reasonable coherence.

            The problem with current line array technology is phase coherence over vertical angle range. Electronic phase alignment only works over a small range of vertical angles. There have been various partial solutions - I once had a pair of Electrovoice LR-7 that were curved to focus the sound over normal High School auditorium distances, and the EAW LS832 has proportional length tweeter and midrange lines like the MacIntosh speakers.

            The gaps between tweeters also causes anomalies, and the end effect of line sources causes fr lobes even on axis at certain distances.

    1. Servos can't correct for the overhang at resonance, which lasts as long as the note! Tonal bass instruments in the rhythm section like bass drum, bass guitar, pizzicato Contrabass and staccato Tuba (think New Orleans) produce anharmonic distortions through even servo woofers.

  5. Just for historical interest, KEF designed a speaker in the 80s for high level monitoring, the KM1. It was rated to play 120 dB from 40 Hz to 20 kHz with a maximum of 0.5 dB compression. I was an actively powered speaker with 4 12" woofers, 2 special heat synched B110 mid ranges and a 2" dome tweeter with a magnet that made large woofer magnets look small.

    1. The KEF KM1 was designed for the BBC's Maida Vale Studio. Referring to my post above, Peter Thomas worked at Maida Vale at that time and set up PMC in 1990 on the back of agreeing to design new large scale monitors for them, which presumably replaced the KM1. That was the BB5, his flagship range ever since.
      The new QB1-A beasts (and their big brother QB1D-A at 8,800 watts per channel) are clearly modelled directly on the KEF KM1.

      http://international.kef.com/explore-kef/kef-museum/1980s/professional-series-model-km1-1984-88
      https://pmc-speakers.com/products/professional/active/qb1

  6. If so, that is decided to call: "IRS Killer" as the name for a new speaker, I think a lack of respect for the memory, by the new manufacturer, for whom he has called his mentor, so many times.

    I'm not sure that if he were alive, he would have liked that name, because the IRS is a classic among the speaker systems of all time, (it is the Genesis of Genesis) and a great effort within the technology of 30 and more years ago, that despite from this time, it can still be considered a reference system.

    A fair tribute could be a name related to A. N., something similar to BHK. IMHO.

        1. Indeed it is and I won't be calling the new speakers IRS Killer. I just repeated the name Arnie had given his prototype.

          The new speakers we produce in Arnie's name will be labeled the AN Series. Like AN1, AN2, etc.

          1. AN1 ...., It sounds better.

            The verb adjective killer, does not do justice to the quality of IRS V, or ask those who have had the privilege to listen to them in the PS Audio-room No. 1

            Being me, strictly vegetarian since 1970, I feel repulsion against words or deeds, which imply violence. But this is the opinion of a single individual.

  7. Paul, there are two designers that might be worth talking to, I think you know them both. Well three if you add Dave Wilson. I am thinking Richard Vandersteen, and Bill Dudleston. Richard and Bill have very different approaches to midrange. Richard uses 5" drivers, while Bill is using what seems to be a quite large driver.
    A while back I heard that Vandersteen often got Thiel drivers in the mail for repair. Because both stressed time alignment, using first order crossovers, some Thiel owners thought they were the same company. What I was told was that Richard told Thiel what change he could make to solve the problem, but it wasn't done, and they continued to have problems with the driver.
    I don't think any one of those guys would be concerned about the competition, and might be happy to assist in completing Arnie's last design. Just a suggestion.
    All three design speakers that would be on my short list, if I was able to replace my 1997 Focus.

  8. I don't think I will buy a speaker simply because it can play loud to 120 db which damages one's hearing. Even people have this kind of speakers, I suspect most of the time they will turn the volume down. So why Paul wants to proceed with the making of a speaker that can play loud to 120 db?

    1. Turning your statement into a question, what makes you buy a speaker? In my case it was one that works really well at low volume. Loudness hides more than it reveals. To me a speaker that at relatively low volume provides detail and structure is ideal. My 20 year old son is learning that music can sound better and be more enjoyable at lower volumes through better speakers.

    2. This may sound a bit weird coming from someone who is a techie and 'measurementalist', but what I look for in a speaker is something I would call 'effortlessness'. It should sound as if it has massive reserves to cope with higher volumes and radical changes of program material. It is one of the reasons I have traditionally always favoured big speakers. I cannot put a number on it, but being able to reproduce sound accurately at a volume level far higher than you would normally want must be part of it.

    3. A constant 120dB, like the sound of rotating and impacting machines with metallic resonances, will damage your hearing if you are exposed daily.

      In real acoustic music, the 120dB peaks only last a few milliseconds out of an hour long symphony. Our hearing mechanism has protection systems that keep us from going deaf from lightning, and the loudest sound of all - CHEWING! Mastication of crunchy foods can produce the equivalent of over 130dB through bone conduction.

      Still, the removal of orcehstral peaks by normal recording practice, radio and internet compressors, amplifier and speaker limitations is dynamic distortion that reduces the feeling of live music. I know this because I made stage speakers with 120dB full range capability to replace PA for a live venue and produced a thousand concerts.

      These had consistent reports that the conservatory trained musicians in the audience COULD NOT TELL we were using speakers when you have sufficient linear output and low temporal distortion. They also produce higher audience euphoria levels than the concerts I attend at Carnegie Hall and Lincoln Center because the chamber sized room does not have the acoustic peak compression of large halls and further, greater articulation and intimacy.

      I also discovered that string quartets peak over 110dB at 2 meters, and a concert grand piano peaks over 120dB without causing hearing loss

      1. I hope you are right about the brief spell of loud sound will not harm one's hearing but I wonder why one has to wear ear muff in a shooting range. One does not have to have 120 db passages in order to enjoy the music and I value my remaining hearing not to subject myself to sound 120 db sound.

  9. Speaking of live music, some of the very most wonderful musical moments I've ever enjoyed have been those live shows with Wesla Whitfield. Today I got notice that she has gone into hospice care. Last year was sad when her retirement from performance was announced. I didn't realize it was due to such a serious illness.

    Take a listen and buy some of her recordings. There is little you can buy which will bring more beauty from your hi-end system.

    https://www.youtube.com/watch?v=A1ShN1cniBc

  10. Hi Paul,

    To the absolute annoyance of many patrons, my dear husband has no better idea that to measure SPL while at Disney hall concerts. Though our seats are in front of the orchestra, they are usually around 30 to 40 yards away. He has lots of things to tell me, which I usually ignore, including the tuning difference form his iPhone app (always a bit sharp by the orchestra), or the sound pressure level when the hall is silent right before the start of the music playing. He tells me he has never measured 120 dB from our seats. Even with loud rousing music.

    1. Right, and those classic measurements of 120dB are directly in front of the orchestra. Just like you would not sit there you also would not sit that close to your speakers.

      But, look at it this way. It's headroom. A speaker that can effortlessly reproduce peaks of 120dB without distortion is likely to sound completely unrestricted in its playback of dynamics. In the same way, a big 1,000 watt amplifier has tons of headroom which is never used, but always valuable. Or a 500 horsepower motor to get you to WalMart.

      1. Whatever, Paul!

        My issue is to make sure that when he plays his "stereo" at a low volume, it sounds as good or as accurate as when he plays it loud. Actually, it is relatively easier to make it sound accurate at normal levels. But very loud or very quiet, it is a different matter.

        And even when we sit closer to the orchestra in Santa Barbara, he tells me it doesn't get this loud, 120 dB. He compares the SPL at home with the live concert and you still don't get the same "feeling" of being there....

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