Henry Kloss designs

[Guest nolanpk]

Hello group. My name is Pat and I have just registered after having visited this site several times. I am a fan of Kloss. I own four Large Advents and a pair of KLH Model 6 and a pair of Cambridge Model 6.

I have a question. Does anyone know what speaker models Kloss designed before he left KLH?

Thanks. I am looking forward to your input

[Andy]

Kloss played a part in every product KLH made, he left the company in 1967. The model 6 was an exellent speaker, produced from 1958-1972. He also was very responsible for what came after, from 1968-72.....such as speaker models 12,5,23,31,32,33. they were all acoustic suspension and had drivers which were his design. There was very little that was ground breaking in the 70's and by '76 KLH's products were a shadow of what they had become famous for.

[Guest nolanpk]

Thanks for your reply. Did he design the Model 17 and 20? I understand that he had a hand in everything, but I wonder if the 17 and 20 are derivatives of the Model 6.

[Andy]

He would have had major input in both the 17 & 20. The Model 17 was introduced in 1965 and the Model 20 speakewr went with was the model 20 modular phono/radio system of 1966-71. The Model 6 had a larger woofer magnet and was a more robust speaker and could reproduce slightly lower frequencies.

[tysontom]

>He would have had major input in both the 17 & 20. The

>Model 17 was introduced in 1965 and the Model 20 speakewr went

>with was the model 20 modular phono/radio system of 1966-71.

>The Model 6 had a larger woofer magnet and was a more robust

>speaker and could reproduce slightly lower frequencies.

The KLH Model Seventeen was one of KLH's most important products, and represented probably the best value of any speaker made by that company during the 1960s. Henry Kloss went all out to offer a loudspeaker that, at $69.95 list, had the highest-performance-per-dollar available from the company. The Seventeen was just barely behind the KLH Model Six in performance, but was designed to compete with Acoustic Research's AR-4 and AR-4x. The Seventeen had slightly deeper bass output than the AR-4/4x, but the latter had lower distortion; both speakers had superb tweeters and a very balanced overall sound. KLH speakers were always noteworthy for their excellent transient-response throughout the midrange and treble -- a hallmark of a well-designed speaker.

--Tom Tyson

[soundminded]

When I was in school, we tried an interesting experiment with a pair of KLH model 17s. In my dorm, there were built in desks on each side at one of the room end with very large knee wells and a masonary wall between them. We placed the speakers inside the knee wells in a corner aimed diagonally at the center of the masonary wall so that no direct radiation reached the center of the room. It seemed to me that there was a considerable improvement in bass and the treble was not much attenuated probably owing to the hardness of the wall. In another experiment, we compared them directly to AR3. While AR3 had obviously much greater capability at very low frequencies, it was the consensus that over most of the audible range, KLH model 17 sounded more accurate reproducing music. Very surprising results. IMO KLH Model 17 may have been the greatest speaker value ever offered (I don't own a pair but I do have 2 pairs of Model 6s.) Paired with a high quality subwoofer, KLH Model 17 should still give a good account of itself against many more modern designs. Not bad for a budget speaker built 40 years ago.

[Andy]

One more interesting thing about Koss's work, he was a master at frequency contouring. In the 1996 Lander interview, he said he did an A B comparison test with a cheap Radio shack speaker and a KLH model Six. Using a graphic equalizer to depress the center octive he made the the Radio Shack speaker - in his words "sound more like a model Six then the Model Six". This is how Kloss got such great sound out of a 3 inch speaker in the Models Eight and Twenty One radios.

Also, the cousin of the model Seventeen was the Model Twenty used for the model Twenty phono/FM system which is the same speaker except for a shorter voice coil winding to reduce the impedance to 4 ohms. I've always been impressed with how the Model Twenty sounds....it cost only $400 back in 1966 and was the modular system by which others were judged. Don't pass them up when you see them at a yard sale or chuch fair, they're really nice!

[tysontom]

“…In another experiment, we compared them (KLH-17) directly to AR3. While AR3 had obviously much greater capability at very low frequencies, it was the consensus that over most of the audible range, KLH model 17 sounded more accurate reproducing music. Very surprising results….”

Soundminded

Nothing could be farther from the truth, of course! Please don’t think I am criticizing the results of the dorm-room listening test. I am not! I'm sure that your description is what they heard.

The observation in the dorm room, however, describes the intuitive thinking of KLH’s pioneer, Henry Kloss. Kloss successfully attempted to design speakers that would sound clean and pleasing, with great deep bass, yet would make a no-compromise speaker such as the AR-3 sound muted or less accurate, as the dorm-room comparison appeared to demonstrate. What was at work here? This dorm-room effect is *precisely* what Henry Kloss was adept at doing: he knew that many competitive speakers, notably ARs, had a reticent quality (particularly the on-axis sound), and he specifically designed (“voiced,” as some say) his speakers to have a brighter, more “immediate” and detailed sound. This is done by increasing the output of the tweeter on axis for greater first-arrival energy, up close, even if it meant a loss of off-axis response.

Kloss was also keenly aware of the low sensitivity (efficiency) of AR speakers, and he designed his speakers to have higher efficiency, even at the expense of ultimate low-distortion bass, a characteristic of AR speakers. Only the most discerning listeners can detect a difference of one or two percentage points in distortion, so a small sacrifice in distortion is worth it to gain increased sensitivity. Even with its 4-ohm impedance, an AR-3 or AR-3a has lower efficiency in an A-B comparison than a comparable 8-ohm KLH Six, Seventeen or even Advent. Kloss was aware that audio dealers rarely set acoustic levels to compensate for efficiency differences, and he knew that people evaluate speakers in a showroom typically in the near field, not well back into the far field. This is where the KLH Seventeen or Six would sound more “immediate” than a speaker such as the AR-3. In a showroom, or in some forms of side-by-side comparisons, a speaker such as the KLH Model Six, KLH Seventeen and even The Advent Loudspeaker, sound considerably brighter and more detailed than a design such as the AR-3, and the sensation is that the KLH sounded better. More “pleasing” might be a better adjective, but certainly not more accurate.

Another factor was the significant interference effects in the AR-3/AR-3a due to (1) cabinet-edge diffraction and (2) mutual-radiation interference effects of the two wide-dispersing dome tweeters. These effects are noticeable and measurable when one listens to an AR-3 up close; however, these effects are totally swamped and have no effect in the reverberant field, or in a typical listening room. By simply moving a measurement microphone around in front of an AR-3, the dips and peaks caused by diffraction will move up or down in frequency, showing that there is no anomaly with the drivers themselves; furthermore, once back in the far field, those effects can’t even be measured.

As we've stated many times, the AR-3’s sonic accuracy really goes without saying, and it has been proven definitively, time and again. No KLH or Advent speaker has ever been subjected to the scrutiny of public live-vs.-recorded concerts of the type done by AR with the AR-3. These concerts, widely reported in the press, demonstrated the sonic accuracy of the AR-3. Furthermore, test reports from nearly every audio publication, including *Consumer Reports,* usually proclaimed the AR-3 to be the best commercial loudspeaker that could be purchased for any price. Even *Popular Science* magazine in the Fall of 1963 picked the AR-3 system during an exhaustive, two-month side-by-side comparison with virtually every known high-quality loudspeaker of the day -- including the KLH Sixes and KLH Fours -- to determine the top choice in picking a stereo system. The most famous test of the AR-3 was by Hirsch-Houck Labs, in which Julian Hirsch proclaimed, “The sounds produced by this speaker are probably more true to the original program than those of any other commercially manufactured speaker system we have heard.”

So what this says is: what you hear the on the first impression or in a dealer showroom is usually unrelated to accuracy in high-fidelity reproduction. Whereas Edgar Villchur was a brilliant speaker designer, Kloss was perhaps equally brilliant in knowing how to design a loudspeaker (for less money) that will sound great the first time and sell well!

--Tom Tyson

[dynaco_dan]

Hi Tom;

An excellent write-up, thank you very much.