What cabinet improvements have you made?
Model 2 & 2SW cabinets are far too resonant. You can find obvious resonant areas by simply tapping around with a finger. I'm going to try and reduce that. Has anyone been there & done that?
Thanks.
Model 2 & 2SW cabinets are far too resonant. You can find obvious resonant areas by simply tapping around with a finger. I'm going to try and reduce that. Has anyone been there & done that?
Thanks.
And a mechanics stethoscope will get you even more info i=on what parts of the cabinet are moving.
dave
I added some hard wood strips on the inside for stiffening.
On the outside I added a 6mm thick Finnish birch plywood glued with a 1mm thick visco elastic glue. Developed specially to damp resonances.
On the outside I added a 6mm thick Finnish birch plywood glued with a 1mm thick visco elastic glue. Developed specially to damp resonances.
Cool! How did the sound change?
I'm going to try some of that autosound deadening mat. News in a couple days.
I'm going to try some of that autosound deadening mat. News in a couple days.
Try to add a thin layer outside the box to form a constrained layer.
https://en.wikipedia.org/wiki/Constrained-layer_damping
By doing the total weight does not exceeds 50% from original so you can still move the speaker. And you will have a much stiffer construction with less colorization.
I used SVEDAC DG-A2 https://www.swedac-acoustic.se/produkter/stomljudsdampande/damplim-dg-a2/
https://en.wikipedia.org/wiki/Constrained-layer_damping
By doing the total weight does not exceeds 50% from original so you can still move the speaker. And you will have a much stiffer construction with less colorization.
I used SVEDAC DG-A2 https://www.swedac-acoustic.se/produkter/stomljudsdampande/damplim-dg-a2/
Autosound damping will add mass without incvreasing stiffness, lowering the frequencies of any resonances, and widening their Q. This will make them more audiable.
What does teh enclosure look like on the inside?
dave
What does teh enclosure look like on the inside?
dave
OK the deadening mat needs a rethink.
It sounds like the best way to go is to increase the frequency of individual resonances as much as possible? Thus moving them up in the spectrum to a region where the cabinet just isn't as 'energized'?
If so, it sounds like internal lightweight stiffeners, glued tightly to each offending panel, is a better idea. Obviously I can use wood for these but how about carbon fiber tubing with a square cross section, and a rigid glue bond (epoxy maybe?).
For those unfamiliar, model 2 & 2SW have an internal wood frame that divides the large panels into small rectangular sub-areas. I'm thinking one diagonal brace glued down tight into each of these spots. Sound like a better idea? And many thanks for your input.
It sounds like the best way to go is to increase the frequency of individual resonances as much as possible? Thus moving them up in the spectrum to a region where the cabinet just isn't as 'energized'?
If so, it sounds like internal lightweight stiffeners, glued tightly to each offending panel, is a better idea. Obviously I can use wood for these but how about carbon fiber tubing with a square cross section, and a rigid glue bond (epoxy maybe?).
For those unfamiliar, model 2 & 2SW have an internal wood frame that divides the large panels into small rectangular sub-areas. I'm thinking one diagonal brace glued down tight into each of these spots. Sound like a better idea? And many thanks for your input.
Yes. You will never get rid of (potential) resonances. The idea is to move them up to where they become very unlikely to ever get enuff energy to set them off.
And if the Q goes up, it is even less likely to get excited as music rarely has sustained “high-frequency” sequences where the same note is played continuously enuff to pump suffiicent enegy into the panels at the frequency that will set the resonance off.
dave
Plywood is practical. If you can extend the brace to brace multiple surfaces.
The braces should have aspect ratios that are higher than the aspect ratio of the panel being braced. This means it is likely the brst braces for the shape of the Beverige will be vertical.
dave
Here's a pic of the open box, these are kind of their own thing. The walls can't be any more than a quarter inch thick! It's like cheap basement wall paneling and it is crazy resonant.
The 6 rectangles on each side wall are the areas I'm on about. They have a pronounced tone. Equally bad is the giant back door which is the same thin stuff, it booms much deeper and very loud. The slanted areas at the front were far quieter.
Cross bracing is not an option as the box is completely filled with foam.
The 6 rectangles on each side wall are the areas I'm on about. They have a pronounced tone. Equally bad is the giant back door which is the same thin stuff, it booms much deeper and very loud. The slanted areas at the front were far quieter.
Cross bracing is not an option as the box is completely filled with foam.
Yes with the back removed. Here it shows the foam stuffing. The dents in the foam are from wood blocks glued onto the door, I'm guessing not so much to seat the foam as to manage the resonance of that large panel... ?
You can see those little pockets on the side walls have nothing in them.
You can see those little pockets on the side walls have nothing in them.
That is going to be a PR like the removable back of the original Hereseys.
Can you rip the foam off (it is not that useful should be replaced with something more effective0.
Given you want to be able to remove the back, it will likely need to have braces from the front to the bacfk and the back screwed into it. It may also need some further stiffening. This may be easier to do on the outside.
What are the restictions given that one wil still need to be able to access and remove the ESL panels?
dave
Can you rip the foam off (it is not that useful should be replaced with something more effective0.
Given you want to be able to remove the back, it will likely need to have braces from the front to the bacfk and the back screwed into it. It may also need some further stiffening. This may be easier to do on the outside.
What are the restictions given that one wil still need to be able to access and remove the ESL panels?
dave
My pair was painted white. I like wood so the best option for me was the constrain layer method in combination with bracing on the inside.
Remember that this speaker can not be compared to a speaker with dynamic elements. Moving mass is the air in the acoustic lens, and the radiating area is enourmus compared to other speakers. So comparing the rigidity of the box with a small ordinary speaker is not valid. That said the speaker do benefits from reducing vibrations even though the vibrations from the beginning is almost zero
Remember that this speaker can not be compared to a speaker with dynamic elements. Moving mass is the air in the acoustic lens, and the radiating area is enourmus compared to other speakers. So comparing the rigidity of the box with a small ordinary speaker is not valid. That said the speaker do benefits from reducing vibrations even though the vibrations from the beginning is almost zero
Roughly 10 years ago I spoke with seller on craigslist near me with a pair of Model 2 for sale.
He said they had been rebuilt by Rick and that included additional cabinet bracing and he thought they were better
before the cabinet work.
How about cutting 3/4" mdf into panels the same size as the cabinet sides and temporarily clamping/squeezing in place
with cheap bar clamps from harbor freight.
He said they had been rebuilt by Rick and that included additional cabinet bracing and he thought they were better
before the cabinet work.
How about cutting 3/4" mdf into panels the same size as the cabinet sides and temporarily clamping/squeezing in place
with cheap bar clamps from harbor freight.
Couple more pictures. You can see the foam is just big blocks you can remove.
I was wrong about the wall thickness, it's not 1/4 inch, it's even less! It's 3/16.
I was wrong about the wall thickness, it's not 1/4 inch, it's even less! It's 3/16.
planet10 I've stumbled onto the fact you used to have Tangent RS8's. Me too!! Betcha don't hear that every day.
I just barely got a rosewood pair out the door right as the Canada operation was shutting down. I loved those speakers for many years.
Anyway can you believe these Bevs were screamin' state of the art? They are such an odd mix of incredible stunning performance, not done before or duplicated since, and totally cheesy couple-guys-in-a-garage physical construction.
I take your point about a whole new back panel, thanks. This cabinet is only driven above 100Hz and the back panel booms probably well below that now. So I'm gonna have to raise its' frequency a lot.
For the side pockets I'm thinking 'blades' of 1/4" plywood that are maybe 1.5" tall mounted perpendicular to the paneling like an inverted letter T. They would bisect the long axis of each pocket, and again planet10 thanks for the charts, very helpful. 1.5" inches seems a practical maximum to still allow the foam blocks in & out.
I had an RH Labs subwoofer with the Tangents, holy crap that thing wouldn't fit in a bathtub 🤘
I just barely got a rosewood pair out the door right as the Canada operation was shutting down. I loved those speakers for many years.
Anyway can you believe these Bevs were screamin' state of the art? They are such an odd mix of incredible stunning performance, not done before or duplicated since, and totally cheesy couple-guys-in-a-garage physical construction.
I take your point about a whole new back panel, thanks. This cabinet is only driven above 100Hz and the back panel booms probably well below that now. So I'm gonna have to raise its' frequency a lot.
For the side pockets I'm thinking 'blades' of 1/4" plywood that are maybe 1.5" tall mounted perpendicular to the paneling like an inverted letter T. They would bisect the long axis of each pocket, and again planet10 thanks for the charts, very helpful. 1.5" inches seems a practical maximum to still allow the foam blocks in & out.
I had an RH Labs subwoofer with the Tangents, holy crap that thing wouldn't fit in a bathtub 🤘
Not many RS-8s ever made it to NA. We sold quite a few pairs, but they never got it quite right. I blame on them trying to grow too fast — ill-fated pre/power & TT. I di duse the one working channel of one of the wpower amplifiers to drive a sub for thew QUAD 57s hanging from the ceiling of my shop in the later half of the 80’s.
They didn’t have the same seemlessness of the RS2/4. But they were PRETTY.
I’d definitely play with damping other than foam. I imagine layers of damping of decreasing density as you go from back to front. Dense felt, less dense felt, evemn more if you can find it, then a fluff of well teased acoustistuff, a blanket of Ultratouch insulation, i’d avoid fiberglass. You might want to add a “blanket: of thin, audio transperant cloth as a screen to keep and dust fibres from getting behind the stators.
dave
They didn’t have the same seemlessness of the RS2/4. But they were PRETTY.
I’d definitely play with damping other than foam. I imagine layers of damping of decreasing density as you go from back to front. Dense felt, less dense felt, evemn more if you can find it, then a fluff of well teased acoustistuff, a blanket of Ultratouch insulation, i’d avoid fiberglass. You might want to add a “blanket: of thin, audio transperant cloth as a screen to keep and dust fibres from getting behind the stators.
dave
My pair had the most absolutely gorgeous rosewood veneer. Pretty, indeed. I never blew a driver but years later swapped in the titanium version of the Audax tweet, padded down a couple dB as I recall.
I worked for a dealer, Marshall Music in East Lansing, Michigan. Back then I paid for the RS8s by mailing a money order to Canada, I got a call offering to send it back & I said 'send me the speakers instead'. It was all right as the shutdown happened.
I'm not quite getting your comments, but first be aware that black speaker element is electrified at three thousand volts. We need to be careful what touches it. The original foam blocks are right up tight against the panels & not bothered by the voltage.
OK, 'tapered density layers' in my padding; Most dense on the rear door and tapering toward the transducer, or the other way 'round? Why? Thanks.
I worked for a dealer, Marshall Music in East Lansing, Michigan. Back then I paid for the RS8s by mailing a money order to Canada, I got a call offering to send it back & I said 'send me the speakers instead'. It was all right as the shutdown happened.
I'm not quite getting your comments, but first be aware that black speaker element is electrified at three thousand volts. We need to be careful what touches it. The original foam blocks are right up tight against the panels & not bothered by the voltage.
OK, 'tapered density layers' in my padding; Most dense on the rear door and tapering toward the transducer, or the other way 'round? Why? Thanks.