Was Heresy the First Sealed Speaker

[ishwash]

41 minutes ago, wdecho said:

I thought I needed a Crown DC300A with 190 watts of power back then. I still have it needing repairs but it is not worth the trouble or expense. There are SS amplifiers that sound great with our speakers as well. I have built 10 or more of the Nelson Pass Class A amplifiers. I now have 6 complete ones I rotate in and out of my system. They are in the range of 25 watts or less and are called Firstwatt and Zen clones. They cost around $700 to build and require a preamplifier as well. Retail Firstwatt amplifiers are in the $3,000 and higher range. You get the same or better sound with a good SET amplifier. 

Where were you guys when I was being a dumb-*** for most of my life, the last 25 years of which I spent 25 miles from the Klipsch Hope manufacturing plant. ..smile...oh well...education is never ending... 

[seti]

On 3/25/2018 at 2:53 PM, dirtmudd said:

 

https://www.cnet.com/news/did-the-best-speakers-of-the-1940s-sound-better-than-your-speakers/

 

 

 

 

Yeah that is a cool one indeed and very early. There is also the Lansing Iconic. I am not sure if it predates the 757 or not.

[ishwash]

Ok...I am with you on not needing a high power amp, and I get it that large amps were not being used to run those speakers in movie houses in days of yore, and I get it that some of those Yore speakers may have accidently ended up meeting the criteria of a sealed speaker, which I very much doubt...smile....

 

Now, Another Burning Question Has Arisen (burning for me anyway):

 

When I ripped my music to flac and when I converted my vinyl albums to high bit rate mp3 digital, I did not do it with volume leveling because I figured VL might degrade quality. As a result I have music with an annoying difference in the level in which it plays back such that I feel I have to stay pretty close to my remote to raise or lower the volume.

 

Also, I hate having to get up and go to the amp to adjust volume or to re-listen or skip to the next song. I have been known to play a song 10 consecutive times. With your small amps have you solved these problem? Having a remote is a strike issue for me...

[ishwash]

Just another post to ask followers to respond to my last post which originally said little or nothing but was later revised with another question. Sorry...

[Guest wdecho]

I do not miss not having a remote. I just figure being retired I need the little bit of exercise getting up and down. You would need a pre or buffer with a remote if it were a deal breaker. 

[DizRotus]

3 hours ago, ishwash said:

With your small amps have you solved these problem? Having a remote is a strike issue for me...

 

No.  Huge volume is available with mini-watts.  You would not want to use an amp that "controlled" volume by running out of steam.

 

IMO, you were right not to use volume leveling.  One of the advantages of dynamics is the difference between the loud and soft passages.  For example, when I listen to Hi-Res recordings using a Pono player hard wired to the aux input of the car's stereo, it's necessary to adjust the volume up and down.  If I don't, the quiet passages are buried by road noise, but then the loud passages blow me out of the car.  The alternative was compressed music mixed to sound good on Auratone cubes.  The problem is not present in the home.  I'd rather  deal with it then be fed compressed music.

 

On a related note, I find that music passages in films are too loud.  But turning the music down then makes the dialogue unintelligible to these geriatric ears. 

 

[ishwash]

Ok, yeah, that would be sorta like using your cell to control the volume when you are bluetoothing or feeding your vehicle via aux input. Not good to do, cell must be on max.

 

When I am alone and listening, I will repeat play songs all over the place. That is what the real issue is with me. I can handle the volume changes myself, it's when others are present that objections are made to volume changes. 

 

My habit of repeat play listening was hard on my vinyls too back when vinyls were all one had. Repeat play causes tone arm skips which cause scratches. Also, out west where the wind and the dust blows and seeps into homes, the dust was very hard on vinyl. You needed to clean them before playing and you needed to clean vinyl after playing if the wind was blowing. Dust particles can even lodge in the music groove, and they mada a cool little brush thingy to get them out. I lived out west during the advent of CD's. I thought it was the best thing to happen since sliced bread, I can't imagine going back to vinyl. And issues with turntables such as channel separation, signal to noise ratio, there was another which had to do with level of quietness of background, maybe, that was signal to noise. I know to have everything right was a balancing act, and you were dealing with stuff that might be as much imagined as real.

 

Thanks again, my friends, especially you, friend wdecho!

[garyrc]

Yes, that efficient!

 

Below is helpful info from Klipsch, much more immediately useful that the 1W, 1 Meter ratings.  Even though, with a Klipschorn, 115 dB at 63 watts in a 3,000 cu ft room is labeled "Too Damn Loud,"  it is needed for very brief peaks.  IMO, we had might as well produce that brief 115 dB with an amp's continuous RMS rating, if we can afford an amp that will put out 63 watts continuously.  It is theoretically possible  to produce the leading edge of such a peak with 6.3 watts, in a 3,000 cu ft room, but I wouldn't feel safe trying it.  Several measurements of large live orchestras, up fairly close, have indicated that there are very brief (approx 20 to 200 ms) peaks as high as 115 dB. This is the "full scale" (fs) level for frequencies below 80 Hz that THX came up with. Paul Klipsch, who recorded and measured the SPL level of several orchestras, said something like "To get the blood stirring levels of a symphony orchestra, you need 115 dB peaks at your ears." At other times he emphasized the brevity of these peaks, and averred that some SPL meters using needles lag 13 dB below the actual value on very brief peaks, due to needle ballistics.  THX measured 110 dB levels in the bass for 70mm roadshow showings of The Empire Strikes Back three and one half decades ago. I'm assuming that these measurements were taken with flat, or "C" weighting, and "fast."

 

See the second page of this Dope from Hope for a marvelous chart that will give you the power needed for Klipschorns, La Scala, Belle Klipsch, Cornwall, and Heresy.   Notice that the Heresy will reach the fs level (Reference level peaks) for main speakers in cinema of 105 dB continuously (never done, AFAIK) with 45 watts, in a 3,000 cu ft room.  Almost all subwoofers, of course, have their own amps, a protective limiter (a few don't), and need to go 10 dB higher than the mains.

 

So, if 63 watts is enough for a Khorn, what would it take to produce an identical level with a speaker of average efficiency?  Taking a sensitivity of 90 dB @ 2.83 volts @ 1M as average [generous] the answer is 2,016 watts.   You could get a Mcintosh 1 channel amp (MC2KW) that produces that power for a mere $40,000.00  Of course, you would need one for each channel.

 

 

Klipsch 2 page treatment:

http://assets.klipsch.com/files/Dope_770100_v16n1.pdf

[ishwash]

That does explain a great deal!

 

I see your equipment too, just as interesting to see what you are running as to read your post.

 

So if you want it all and you want it now, for the instantaneous loudness, you may need a medium size amp. However, for keeping your equipment and your ears safe you must exercise a bit of self control (not good at that) when choosing the amp for any of the Heritage Klipsches and low power amps will work very well. It sort of takes care of itself, I suppose, because unless you are high on booze or drugs you probably are not and you shouldn't have your system running that cranked up anyway. And the Dope From Hope illustrates just how efficient his stuff really was (is). I keep feeling I should capitalize He or Him when referring to Mr. Klipsch...smile...

 

As an ex-engineer I am used to discussing incremental or improved efficiencies of 2 or 3 percent, and that is what I was picturing in my mind. Klipsch's speakers are way more bettah!

 

 

[ishwash]

I still think that for living areas and dens of normal size in which one may only have one corner available for a Khorn and limited funds, put one Khorn in there and run everthing in monaural. I doubt that you would even notice the lack of two-channel. I bet it would be a nice setup for folks with regular size houses who long for a Khorn.

 

Gonna now shutup...

[DizRotus]

1 hour ago, ishwash said:

I still think that for living areas and dens of normal size in which one may only have one corner available for a Khorn and limited funds, put one Khorn in there and run everthing in monaural. I doubt that you would even notice the lack of two-channel. I bet it would be a nice setup for folks with regular size houses who long for a Khorn.

 

Gonna now shutup...

 

It would indeed.

[Guest wdecho]

I've read all my life the charts specifying what power one needs to recreate a live performance and at one time I was a believer. Now I just sit back with friends using my 1 watt SET I just built listening to them say turn it down some where we can talk. Nelson Pass in one of his listening rooms using full range speakers with a 95db rating with power meters hooked up showed that on peaks the most power being used was in the 5 watt range. That is on peaks in a large listening room. Another arguing point would be not looking for an amplifier with a power rating that would reach the peaks on the charts with that solely in mind. How does that theoretical amplifier sound at the average listening range and power which with our very efficient speakers is going to be less than a watt. Music lives in the mids and if the theoretical amplifier does not sound best in the mids it is not for me even if does produce enough power for 115db peaks. In general I mean Class A amplifiers whether tube or SS and when you start talking massive power in class A amplifiers one will need deep pockets and good air conditioning. Not necessary either. If our 100db speakers are not good for 5 watt SET's or 25 watt class A amplifiers what speakers are? There would be no market, yet people are willing to shell out substantial sums to get their hands on one of these fantastic amplifiers.

[Tony Whitlow]

There were many, many sealed speakers before either the Heresy or the AR.  Bozak, etc.  They were called Infinite Baffle and were generally large.  Sometimes, people would use the whole next room as the sealed container.  The ARs were pretty muddy sounding, due to needing too much cone excursion.  The AR 1 required 22 times the amplifier as a Klipschorn to produce a sound of equal loudness.  The Bozaks sounded much better, due to larger woofers, up to 4 of them, and bigger boxes. 

AR speakers are acoustic suspension speakers. Don’t know anything about Bozak.


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[Tony Whitlow]

Ok, first though, power has always been used as a measure of ability for an amp. I realize Klipsch are very efficient speakers, but that efficient? How can this amp drive these big speakers?
 
When you use yours, are you only doing it at low volumes, private listening so to speak, and if you want to play your music loud, do you have to use your SS amp?

A SONY WALKMAN can be deafening with KLIPSCHORNs.


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[Guest wdecho]

Bozak's were not acoustic suspension but rather conventional speakers. I was fortunate to see some of their products many years ago. Very impressive speakers. Fine cabinet work.  

[HDBRbuilder]

Heresy speakers were "sealed" in order to create an interior space that could provide an overpressure when the woofer cone's excursion went inward, and an underpressure when the same woofer cone excursion went outwards.  This allowed for the short-excursion woofers used in the Heresy, so that the voice coil would not be slammed, thereby damaging the woofer, itself.  Pretty simple.

[hsosdrummer]

9 hours ago, Tony Whitlow said:

AR speakers are acoustic suspension speakers. Don’t know anything about Bozak.


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Bozak speakers were of infinite baffle design, which completely prevents the woofer's rear wave from cancelling its front wave. (Enclosing the cabinet provides the same acoustic effect as mounting the woofer on a flat baffle of infinite width and height.) Although this does prevent destructive interference, it wastes half of the energy produced by the woofer. Achieving good efficiency and low bass response in an infinite baffle requires a very large enclosure with several woofer drivers. The Bozak Concert Grand speakers in the picture are close to 5 feet high, 3 feet wide and 2 feet deep. Its woofers were similar to Heresy woofers in that they used relatively light cones with an accordion suspension that combined with the sealed cabinet to limit cone movement and reduce distortion (see below). Bozak woofers differed from Klipsch woofers primarily in their cone material: Klipsch woofers used paper/pulp cones while Bozak woofers used a cone made from a blend of paper/pulp and wool fibers.

 

Acoustic suspension speakers like AR and Advent work completely differently. They use a woofer with a heavier cone and a very loose suspension, which lowers its resonant frequency and allows it longer excursion. The enclosure is relatively small and tightly sealed, allowing the air trapped inside to act as a spring on the cone, helping to control its movement. When all these factors are properly balanced the speaker can produce bass as low as 30Hz. However, all of this tomfoolery severely reduces the speaker's conversion efficiency. requiring 10 to 100 times the amplifier power as more highly-efficient designs such as used by Klipsch. This makes it impossible for acoustic suspension speakers to play at life-like volumes without being damaged. The other price paid by acoustic suspension speakers is a big increase in modulation distortion, which is directly proportional to cone movement (more movement = more modulation distortion).

 

Look up the old Klipsch brochure titled "Yawns or goose-bumps?" for a great illustration of the limitations of acoustic suspension speakers.

[Tony Whitlow]

 
Bozak speakers were of infinite baffle design, which completely prevents the woofer's rear wave from cancelling its front wave. (Enclosing the cabinet provides the same acoustic effect as mounting the woofer on a flat baffle of infinite width and height.) Although this does prevent destructive interference, it wastes half of the energy produced by the woofer. Achieving good efficiency and low bass response in an infinite baffle requires a very large enclosure with several woofer drivers. The Bozak Concert Grand speakers in the picture are close to 5 feet high, 3 feet wide and 2 feet deep. Its woofers were similar to Heresy woofers in that they used relatively light cones with an accordion suspension that combined with the sealed cabinet to limit cone movement and reduce distortion (see below). Bozak woofers differed from Klipsch woofers primarily in their cone material: Klipsch woofers used paper/pulp cones while Bozak woofers used a cone made from a blend of paper/pulp and wool fibers.
 
Acoustic suspension speakers like AR and Advent work completely differently. They use a woofer with a heavier cone and a very loose suspension, which lowers its resonant frequency and allows it longer excursion. The enclosure is relatively small and tightly sealed, allowing the air trapped inside to act as a spring on the cone, helping to control its movement. When all these factors are properly balanced the speaker can produce bass as low as 30Hz. However, all of this tomfoolery severely reduces the speaker's conversion efficiency. requiring 10 to 100 times the amplifier power as more highly-efficient designs such as used by Klipsch. This makes it impossible for acoustic suspension speakers to play at life-like volumes without being damaged. The other price paid by acoustic suspension speakers is a big increase in modulation distortion, which is directly proportional to cone movement (more movement = more modulation distortion).
 
Look up the old Klipsch brochure titled "Yawns or goose-bumps?" for a great illustration of the limitations of acoustic suspension speakers.

Why? I have Heresys.


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[garyrc]

11 hours ago, wdecho said:

I've read all my life the charts specifying what power one needs to recreate a live performance and at one time I was a believer. Now I just sit back with friends using my 1 watt SET I just built listening to them say turn it down some where we can talk. Nelson Pass in one of his listening rooms using full range speakers with a 95db rating with power meters hooked up showed that on peaks the most power being used was in the 5 watt range. That is on peaks in a large listening room. Another arguing point would be not looking for an amplifier with a power rating that would reach the peaks on the charts with that solely in mind. How does that theoretical amplifier sound at the average listening range and power which with our very efficient speakers is going to be less than a watt. Music lives in the mids and if the theoretical amplifier does not sound best in the mids it is not for me even if does produce enough power for 115db peaks. In general I mean Class A amplifiers whether tube or SS and when you start talking massive power in class A amplifiers one will need deep pockets and good air conditioning. Not necessary either. If our 100db speakers are not good for 5 watt SET's or 25 watt class A amplifiers what speakers are? There would be no market, yet people are willing to shell out substantial sums to get their hands on one of these fantastic amplifiers.

 

I want (at least) two things:

 

1) Good sound in the average SPL range, which could be somewhat overestimated at  85 dB (just ran an SPL test with The 11 Overtures -  Beethoven on Pentatone SACD; highly  recommended) which -- with Klipschorns in a 3,000 cu ft room, would require 0.06 watts, according to Keele  http://assets.klipsch.com/files/Dope_770100_v16n1.pdf .   I listened to a variety of separate power amps at a very low level (probably 60 - 70 dB) and selected the NAD c272 150 w.p.c. as my basic amp because it sounded best down there, as well as with higher levels.  In those days, some dealers would let you take an amp or amps home Sat night through Mon morning to give it a good long listen, in your own room, with your own speakers.

 

2) Good sound at high SPL, and with good, clean peaks, without clipping.  The largest peaks, on the above mentioned disk, as read on my analog, needle using, SPL meter were about 97 dB (the needle just touching -3 dB with the 100 dB level setting, "Fast," "C" weight).  Those peaks would need 1 watt, according to the chart (2 watts at 100 dB, -3 dB= 1 watt).  But, needle using meters read "up to" 13 dB below the true level of very brief peaks (leading edges) because of needle ballistics, according to PWK (somewhere in Dope from Hope).   So that would give me peaks, conceivably, of 110 dB, needing 20 watts quite momentarily.   O.K., to hit those peaks, I might be able to get along with an excellent 10 - 20 watt amplifier.  Here is where this becomes a personality test.  I would prefer to have more headroom, "just in case."  I would also like to be fully ready in case some of the 115 dB peak levels Paul Klipsch talked about show up.  So, 63 watts would be plenty for me, except I have a larger than 4,000 cu.ft. room, so that might take 88 watts for the loudest plausible brief peak.  The 150 w.p.c. NADs were the closest with a small safety factor built in, and guess what, my dealer measured them at 120 watt RMS ... but still plenty for Khorns in my situation. 

[garyrc]

38 minutes ago, hsosdrummer said:

 

Bozak speakers were of infinite baffle design, which completely prevents the woofer's rear wave from cancelling its front wave. (Enclosing the cabinet provides the same acoustic effect as mounting the woofer on a flat baffle of infinite width and height.) Although this does prevent destructive interference, it wastes half of the energy produced by the woofer. Achieving good efficiency and low bass response in an infinite baffle requires a very large enclosure with several woofer drivers. The Bozak Concert Grand speakers in the picture are close to 5 feet high, 3 feet wide and 2 feet deep. Its woofers were similar to Heresy woofers in that they used relatively light cones with an accordion suspension that combined with the sealed cabinet to limit cone movement and reduce distortion (see below). Bozak woofers differed from Klipsch woofers primarily in their cone material: Klipsch woofers used paper/pulp cones while Bozak woofers used a cone made from a blend of paper/pulp and wool fibers.

 

Acoustic suspension speakers like AR and Advent work completely differently. They use a woofer with a heavier cone and a very loose suspension, which lowers its resonant frequency and allows it longer excursion. The enclosure is relatively small and tightly sealed, allowing the air trapped inside to act as a spring on the cone, helping to control its movement. When all these factors are properly balanced the speaker can produce bass as low as 30Hz. However, all of this tomfoolery severely reduces the speaker's conversion efficiency. requiring 10 to 100 times the amplifier power as more highly-efficient designs such as used by Klipsch. This makes it impossible for acoustic suspension speakers to play at life-like volumes without being damaged. The other price paid by acoustic suspension speakers is a big increase in modulation distortion, which is directly proportional to cone movement (more movement = more modulation distortion).

 

Look up the old Klipsch brochure titled "Yawns or goose-bumps?" for a great illustration of the limitations of acoustic suspension speakers.

 

I agree.

 

In the last few years, the term "acoustic suspension" has been used loosely, as were the speaker cones (sorry).  Some websites and buy-by-mail catalogs have treated "acoustic suspension" as synonymous with "infinite baffle."   IMO, all acoustic suspension speakers are also infinite baffle, but not all infinite baffles are acoustic suspension.  Thank goodness.  Acoustic suspension speakers tend to sound muddy, due to extreme cone travel, while some large infinite baffles, such as the Concert Grand sound tight, clean, and sweet while producing excellent bass, for the reasons given in hsosdrummer's post.  Of course, the minimum cone excursion in the Klipschorn and the Jubilee provides very clean, low distortion bass.