KLH Cabinets ? ? ?

[Guest alcon]

Which early KLH speakers had real solid wood cabinets? Also, which ones were made with veneer cabinets?

[Andy]

I posted a limited reply in the AR forum, but I'm really a KLH collector so......The early KLH speakers, models 1,2,3,4,6 & 7 made from 1957-59 were made of 15-ply marine plywood....amzing cabinets. The best known solid wood model is the model 8 speaker for the model 8 FM raio which was funiture grade solid walnut up to serial number 7500, then they switched to veneer covered plywood through serial number 12000 (est). I've seen models 4 & 6 made of solid wood dating from about 1960-3 but I don't know what type of wood was used. Fiber-board cover with walnut veneer became the standard in the mid 60's for most KLH models, but plywood continued on the small speakers, models 11,14,15 and 19. I don't like to use word the vinyl twice in one day, but KLH started using the stuff in the early 70's and examples like the model 56 from 1976ish are a far cry from the early models. Most of the KLH speakers dating 1964-74 found by collectors..models 6,17,20,22,24,31,32 & 33 are mdf covered with walnut venner.

If you want a rare KLH speaker, it's the model 8 in solid walnut with one 4 inch driver, 500 or so produced! They're are about 7,500 having two drivers but very few with one. about 4,500 plywood single driver units were made.

[Guest alcon]

Thanks for the very comprehensive reply!

[Andy]

Thanks for the very comprehensive reply!

Slight correction to my answer on this post of two years ago, I stated that all early KLH cabinents were 12 ply marine plywood construction...Models 1,2,3,4,5,6 & 7 up to about 1960.

I now believe a less exspensive plywood and a product like Nova-ply (used in early AR's) was also being used in the early years. i've seen several model Ones with a 6-ply plywood and a model Six, SN 003476 with the Nova -ply type material. I think KLH was trying different cabinet constution materials and was looking for a ballance between performance and cost. The 12-ply was pretty unique for a loudspeaker cabinet - but costly. When sales picked way up in about 1959, they simply couldn't use the 12-ply any more. All three materials may have been being used at the same time on different models.

A side note - Henry Kloss was not only a real thinker when it came to electronics, but was self tought in constucting things out of wood - he made is own furniture for is loft when he attended MIT in 1948-52.

Andy

[tysontom]

I posted a limited reply in the AR forum, but I'm really a KLH collector so......The early KLH speakers, models 1,2,3,4,6 & 7 made from 1957-59 were made of 15-ply marine plywood....amzing cabinets. The best known solid wood model is the model 8 speaker for the model 8 FM raio which was funiture grade solid walnut up to serial number 7500, then they switched to veneer covered plywood through serial number 12000 (est). I've seen models 4 & 6 made of solid wood dating from about 1960-3 but I don't know what type of wood was used. Fiber-board cover with walnut veneer became the standard in the mid 60's for most KLH models, but plywood continued on the small speakers, models 11,14,15 and 19. I don't like to use word the vinyl twice in one day, but KLH started using the stuff in the early 70's and examples like the model 56 from 1976ish are a far cry from the early models. Most of the KLH speakers dating 1964-74 found by collectors..models 6,17,20,22,24,31,32 & 33 are mdf covered with walnut venner.

If you want a rare KLH speaker, it's the model 8 in solid walnut with one 4 inch driver, 500 or so produced! They're are about 7,500 having two drivers but very few with one. about 4,500 plywood single driver units were made.

Andy,

Did you say that you have seen Models Four and Six made from solid wood (or did I misunderstand you)? I’ve never seen this. Where did you see them? Solid wood would have been a very poor choice for the cabinet unless it was two-inches thick. Solid wood tends to buckle, warp and split, whereas MDF and plywood are much more stable. Some of the early KLH Fours and Sixes used NovaPly-core veneered wood similar to AR, but I have not seen solid-wood versions. I know that the tiny Model 8 Radio used solid wood at the beginning, much as AR used solid walnut for the first AR-TT, XA and TA turntables, but later turned to walnut-veneer plywood for stability and strength. At one point it was difficult to get small-dimension walnut-veneered plywood, so solid-core wood was the better choice.

Also, did KLH actually mention that their 13- or 15-ply wood was marine-grade plywood? That would imply that it was water-resistant, something that would be totally unnecessary for a speaker cabinet. At one point (and this is true today), multi-ply plywoods were available in more wood-veneer finishes than standard building-grade plywood, but I’m unsure as to whether or not it was marine-grade. Some 15-ply plywood was also known as “Russian Plywood.”

--Tom Tyson

[Andy]

Andy,

Did you say that you have seen Models Four and Six made from solid wood (or did I misunderstand you)? I’ve never seen this. Where did you see them? Solid wood would have been a very poor choice for the cabinet unless it was two-inches thick. Solid wood tends to buckle, warp and split, whereas MDF and plywood are much more stable. Some of the early KLH Fours and Sixes used NovaPly-core veneered wood similar to AR, but I have not seen solid-wood versions. I know that the tiny Model 8 Radio used solid wood at the beginning, much as AR used solid walnut for the first AR-TT, XA and TA turntables, but later turned to walnut-veneer plywood for stability and strength. At one point it was difficult to get small-dimension walnut-veneered plywood, so solid-core wood was the better choice.

Also, did KLH actually mention that their 13- or 15-ply wood was marine-grade plywood? That would imply that it was water-resistant, something that would be totally unnecessary for a speaker cabinet. At one point (and this is true today), multi-ply plywoods were available in more wood-veneer finishes than standard building-grade plywood, but I’m unsure as to whether or not it was marine-grade. Some 15-ply plywood was also known as “Russian Plywood.”

--Tom Tyson

Tom,

In my post of Feb 2006 I had thought that solid wood KLH models from about 1960 did exist....having just seen a pair at a audio show, but they were actually the NovaPly with a veneer. I had not known of Novaply at that time.

As to the use of "Marine" grade plywood, I remember reading in a magazine ad for KLH the use of the word Marine grade. I just looked through all my KLH paper and can't find it. I agree, it does not make sense for a speaker cabinet to be made of this type of plywood. (I'll keep looking for information on this). I've not heard of the term "Russian Plywood" before, but it sounds serious

At any rate - the plywood used (12-ply), must have been a good quality due to the rabbet joints at the corners. Most plywoods don't cut well when a multi- angled edge is cut, they tend to chip and splinter. My 1958 model Six's corner rabbet joints are very nice. Also of interest - they weigh about 2 lbs. more then a 1960's KLH model Six with mdf cabinet construction. I realize this increased weight may be due to the unique epoxy bonded woofer on early KLH's, but I'm still impressed with these early cabinets.

KLH kept using a plywood on the small speakers into the mid to late 1960s - models 11, 14,15,19 and added solid walnut trim on the front edge around the grill, much like the earlier AR-2, AR2a, & AR-2ax (the wrap around front edge veneer type came after about 1966 on these AR's ?)

Andy

[tysontom]

Tom,

In my post of Feb 2006 I had thought that solid wood KLH models from about 1960 did exist....having just seen a pair at a audio show, but they were actually the NovaPly with a veneer. I had not known of Novaply at that time.

As to the use of "Marine" grade plywood, I remember reading in a magazine ad for KLH the use of the word Marine grade. I just looked through all my KLH paper and can't find it. I agree, it does not make sense for a speaker cabinet to be made of this type of plywood. (I'll keep looking for information on this). I've not heard of the term "Russian Plywood" before, but it sounds serious

At any rate - the plywood used (12-ply), must have been a good quality due to the rabbet joints at the corners. Most plywoods don't cut well when a multi- angled edge is cut, they tend to chip and splinter. My 1958 model Six's corner rabbet joints are very nice. Also of interest - they weigh about 2 lbs. more then a 1960's KLH model Six with mdf cabinet construction. I realize this increased weight may be due to the unique epoxy bonded woofer on early KLH's, but I'm still impressed with these early cabinets.

KLH kept using a plywood on the small speakers into the mid to late 1960s - models 11, 14,15,19 and added solid walnut trim on the front edge around the grill, much like the earlier AR-2, AR2a, & AR-2ax (the wrap around front edge veneer type came after about 1966 on these AR's ?)

Andy

Andy,

Actually, I went about responding to your message from two years ago before I realized that it was an old message! Sorry about that. We actually talked about the solid-wood cabinet thing before, so it is old news. Fundamentally, however, none of the manufacturers would try to use solid-stock wood for a cabinet unless the cabinet was very small -- such as in the case for the Model 8 -- which probably indicated that (at that time) small-dimension plywood wasn't available with high-grade wood. NovaPly does indeed look like "core" wood or solid wood, so it's easy to mistake it.

Coincidentally, I also remember seeing the term "marine" plywood somewhere in a KLH reference, but I can't locate it either. The high-strength, multi-ply (12- or 15-ply) plywoods were likely marine or Russian, as I don't think this was available any other way. Veneered marine plywood is quite expensive, however, so that would factor into the mix. The good cabinet shops that supplied companies such as KLH and AR had high-precision milling and routing equipment, and those joints you mention were easily accomplished. There is a specific name for the type joints used, but I can't remember it. I am surprised that the plywood cabinets weighed more than the MDF-style cabinets; it's usually the other way around. I suspect that the old Alnico magnet versions with the epoxy and stuff might have entered into the mix, but you did not mention the exact versions.

It is interesting that you mention the solid-wood trim (molding) on KLH speakers. I am not familiar with many of the models, but the original models used a continuous piece of panel (be it plywood or MDF-style wood) that went past the baffle board, and then veneer was applied to the inside and front edges to make it look like a continuous piece of wood. AR used the solid panel up to the baffle board edge, and then applied solid-core wood, be it Walnut, Cherry, Teak, Korina, Birch or whatever the finish at the time. The problem with this approach was the transition from veneered plywood to solid wood, and the edge was easily identified.

--Tom Tyson

[dynaco_dan]

Andy,

Actually, I went about responding to your message from two years ago before I realized that it was an old message! Sorry about that. We actually talked about the solid-wood cabinet thing before, so it is old news. Fundamentally, however, none of the manufacturers would try to use solid-stock wood for a cabinet unless the cabinet was very small -- such as in the case for the Model 8 -- which probably indicated that (at that time) small-dimension plywood wasn't available with high-grade wood. NovaPly does indeed look like "core" wood or solid wood, so it's easy to mistake it.

Coincidentally, I also remember seeing the term "marine" plywood somewhere in a KLH reference, but I can't locate it either. The high-strength, multi-ply (12- or 15-ply) plywoods were likely marine or Russian, as I don't think this was available any other way. Veneered marine plywood is quite expensive, however, so that would factor into the mix. The good cabinet shops that supplied companies such as KLH and AR had high-precision milling and routing equipment, and those joints you mention were easily accomplished. There is a specific name for the type joints used, but I can't remember it. I am surprised that the plywood cabinets weighed more than the MDF-style cabinets; it's usually the other way around. I suspect that the old Alnico magnet versions with the epoxy and stuff might have entered into the mix, but you did not mention the exact versions.

It is interesting that you mention the solid-wood trim (molding) on KLH speakers. I am not familiar with many of the models, but the original models used a continuous piece of panel (be it plywood or MDF-style wood) that went past the baffle board, and then veneer was applied to the inside and front edges to make it look like a continuous piece of wood. AR used the solid panel up to the baffle board edge, and then applied solid-core wood, be it Walnut, Cherry, Teak, Korina, Birch or whatever the finish at the time. The problem with this approach was the transition from veneered plywood to solid wood, and the edge was easily identified.

--Tom Tyson

Hi Tom;

The joint is called a, "lockmitre joint".

It may have been done with a machine called a, "shaper", back in my high school days.

It was about 2 - 5 horsepower and you could do any profile on a wooden edge using steel or carbide rotary bits.

This shaper was about the size of a large tablesaw and was all cast iron.

I asked this same question a year or so ago and I cannot remember if it was John or Kent or ? (sorry) who answered my question and provided a link.

Today, for the do-it-yourselfer, you would need a router, for 3/4" wood.

My big old 1 HP router only has a 1/4" bit capacity, so it is not large enough for 3/4" wooden speaker projects, at least with the 1/4" mitrelock bit and 3/4" wood.

A router with 1/2" shaft capacity and around 2 HP or larger is needed.

The bits are made with both 1/4" and 1/2" shafts.

The material limitation means it would need to be the 1/2" shaft version.

You would also need to make or buy a metal router table to mount the router under.

Here in Vancouver, I believe that I was looking at close to $700.00 CDN for a router, bit and table to make a few speaker cabinets.

This particular joint profile allows for a lot of glue, a very strong joint.

I downloaded the same photo from the link, I believe.

The Lee Valley catalog has a photo as well and I also downloaded it.

A friend already has the 1/2" shaft bit. MMMMMM

I've also downloaded a rear photo of one of my Heathkit AS-2 speaker cabinet's.

Notice the non-mitrelocked corner joints, along with 3 sides with multi-layered plywood and one with (bottom) standard plywood.

No wonder Heathkit recommended glueing their AS-2/AS-2A inside cabinet seams prior to assembling their speaker systems.

We can see one corner cut to make the kit lower in cost.

The left photo, I believe, is the correct bit.

The right photo is from the LeeValley.ca catalog.

[tysontom]

Hi Tom;

The joint is called a, "lockmitre joint".

It may have been done with a machine called a, "shaper", back in my high school days.

It was about 2 - 5 horsepower and you could do any profile on a wooden edge using steel or carbide rotary bits.

This shaper was about the size of a large tablesaw and was all cast iron.

I asked this same question a year or so ago and I cannot remember if it was John or Kent or ? (sorry) who answered my question and provided a link.

Today, for the do-it-yourselfer, you would need a router, for 3/4" wood.

My big old 1 HP router only has a 1/4" bit capacity, so it is not large enough for 3/4" wooden speaker projects, at least with the 1/4" mitrelock bit and 3/4" wood.

A router with 1/2" shaft capacity and around 2 HP or larger is needed.

The bits are made with both 1/4" and 1/2" shafts.

The material limitation means it would need to be the 1/2" shaft version.

You would also need to make or buy a metal router table to mount the router under.

Here in Vancouver, I believe that I was looking at close to $700.00 CDN for a router, bit and table to make a few speaker cabinets.

This particular joint profile allows for a lot of glue, a very strong joint.

I downloaded the same photo from the link, I believe.

The Lee Valley catalog has a photo as well and I also downloaded it.

A friend already has the 1/2" shaft bit. MMMMMM

I've also downloaded a rear photo of one of my Heathkit AS-2 speaker cabinet's.

Notice the non-mitrelocked corner joints, along with 3 sides with multi-layered plywood and one with (bottom) standard plywood.

No wonder Heathkit recommended glueing their AS-2/AS-2A inside cabinet seams prior to assembling their speaker systems.

We can see one corner cut to make the kit lower in cost.

The left photo, I believe, is the correct bit.

The right photo is from the LeeValley.ca catalog.

Vern,

Thanks for coming to my rescue! Great information!

--Tom Tyson

[dynaco_dan]

Vern,

Thanks for coming to my rescue! Great information!

--Tom Tyson

Hi Tom;

You are always more than welcome, Tom.

You, John, Roy, Kent and Steve and many others have come to my aid when needed as well.

Thank you, all.