Troels usually lines the inside of his speaker builds with bitumen pads. I asked him why he omitted the bitumen on his “The Loudspeaker” project. Because of the 27mm thick Baltic Birch used he said he didn’t think it was worthwhile.
Since I’m using 2 layers of 3/4” (38mm) plus the polyurethane as the meat in the sandwich, I wasn’t planning on adding any either.
But thinking about the project last night I realized that the 10” midrange and the panel behind the 18” that makes the pocket for the crossover and plate amp is just 3/4”. So today I ran out and picked up some bitumen pads from a local supplier and wrapped these panels.
The pads are “peel and stick”, but since I have access to commercial grade contact cement I took advantage. And used a laminate roller to really press in place.
Since I’m using 2 layers of 3/4” (38mm) plus the polyurethane as the meat in the sandwich, I wasn’t planning on adding any either.
But thinking about the project last night I realized that the 10” midrange and the panel behind the 18” that makes the pocket for the crossover and plate amp is just 3/4”. So today I ran out and picked up some bitumen pads from a local supplier and wrapped these panels.
The pads are “peel and stick”, but since I have access to commercial grade contact cement I took advantage. And used a laminate roller to really press in place.
I slipped into the shop a couple of afternoons and completed installing the denim insulation. All interior surfaces recieve the insulation, with the exception of the backside of the front panel. I also covered the backside of the midrange section.
Since I’m working my way out the back I had to install the insulation on the back panel before I can assemble.
The inner back panel is just tacked until tomorrow
The plan for tomorrow is to make the opening for the amp, crossovers, and the final covers. Then install the outer back panel.
Since I’m working my way out the back I had to install the insulation on the back panel before I can assemble.
The inner back panel is just tacked until tomorrow
The plan for tomorrow is to make the opening for the amp, crossovers, and the final covers. Then install the outer back panel.
Great-looking build! I'm a Troels fan, but my next project will be perforce a lot more modest (at least in terms of size) than yours.
The talk of seriously well-endowed speakers reminded me of an old design I read a couple of reviews of in the 90s - the Naim DBL. Has anyone heard of a clone being made of these? I wonder what one could learn from the DBL. Naim always made a lot of claims about the sophistication of their cabinet structure, with the different parts being partially decoupled, but I don't know how much difference it made.
Alex
The talk of seriously well-endowed speakers reminded me of an old design I read a couple of reviews of in the 90s - the Naim DBL. Has anyone heard of a clone being made of these? I wonder what one could learn from the DBL. Naim always made a lot of claims about the sophistication of their cabinet structure, with the different parts being partially decoupled, but I don't know how much difference it made.
Alex
Cabinets complete, ready for finish.
Another long day, but completed the cabinets. I brought in the drivers, horn, plate amp, and the midrange crossover in for a last trial fit.
Planning was good, everything fit.
After installing the outer back panel I hit all the outside edges with a 1/8” roundover bit, then sanded the entire cabinet with 100 grit in a orbital sander.
From experience it’s better to hit the Medex with a coat of primer before starting any final prep. Excited to see what these will look like with some color!
Another long day, but completed the cabinets. I brought in the drivers, horn, plate amp, and the midrange crossover in for a last trial fit.
Planning was good, everything fit.
After installing the outer back panel I hit all the outside edges with a 1/8” roundover bit, then sanded the entire cabinet with 100 grit in a orbital sander.
From experience it’s better to hit the Medex with a coat of primer before starting any final prep. Excited to see what these will look like with some color!
The Mun-17. I've been steadily collecting parts for the last 18 months - just the bass drivers to get now, then I can start cutting wood.
Alex
Busy week at work, got a little time in the shop and built the “jewelry box” to hold the super tweeter.
More time consuming than one would imagine. Built around the idea of the unit being self contained with male plug on the bottom to fit into female receptical on the top of the main speaker cabinet without any wires showing.
For this I purchased mini banana plugs. Photo/details will come with final assembly.
The custom panels to cover the crossovers and hold binding posts, and compression driver attenuator came in. I’ll try figment and take pics tomorrow as I’m prepping and priming.
I would have been happier with the looks if Troels would have designed the crossover/cabinet like the JBL 4344 with the super tweeter on the main speaker cabinet baffle. But I guess this is better by time aligning the super tweeter by placing it rearward and on top. I could imagine that with full DSP you could overcome the time alignment?
I’m hoping with some routering of the “jewelry box” and paint it will look better or at least like it belongs there.
More time consuming than one would imagine. Built around the idea of the unit being self contained with male plug on the bottom to fit into female receptical on the top of the main speaker cabinet without any wires showing.
For this I purchased mini banana plugs. Photo/details will come with final assembly.
The custom panels to cover the crossovers and hold binding posts, and compression driver attenuator came in. I’ll try figment and take pics tomorrow as I’m prepping and priming.
I would have been happier with the looks if Troels would have designed the crossover/cabinet like the JBL 4344 with the super tweeter on the main speaker cabinet baffle. But I guess this is better by time aligning the super tweeter by placing it rearward and on top. I could imagine that with full DSP you could overcome the time alignment?
I’m hoping with some routering of the “jewelry box” and paint it will look better or at least like it belongs there.
First up this morning was to build some riser blocks to elevate the speakers on carts for the painting process.
Then into the booth and a first coat of Chromax 2K high build primer (Automotive). Waited two hours, as spec’d, and then spread some Rage Gold filler (Automotive) on gaps, nail holes, etc
While I was waiting for the primer to dry I built the actual bases for the speakers. The front corners will get rounded over to match the speaker cabinets. The casters are 2 3/4” tall when installed, I made the base 2 5/8” tall to hide the casters. The casters are adjustable, so depending on what type of flooring the casters can be adjusted down if needed. The casters came with a locking mechanism. I will use these in the rear, to be able to lock the speaker in place, which requires a 3 1/2” radius clear area to swivel. For the front I will remove the lock so I can push the location closer to the front corners for better stability.
Then into the booth and a first coat of Chromax 2K high build primer (Automotive). Waited two hours, as spec’d, and then spread some Rage Gold filler (Automotive) on gaps, nail holes, etc
While I was waiting for the primer to dry I built the actual bases for the speakers. The front corners will get rounded over to match the speaker cabinets. The casters are 2 3/4” tall when installed, I made the base 2 5/8” tall to hide the casters. The casters are adjustable, so depending on what type of flooring the casters can be adjusted down if needed. The casters came with a locking mechanism. I will use these in the rear, to be able to lock the speaker in place, which requires a 3 1/2” radius clear area to swivel. For the front I will remove the lock so I can push the location closer to the front corners for better stability.
Usually Sunday is Family Day. Go to the beach, scenic drive, picnic, etc. My wife volunteered to help out a friend, so I went to the shop and spent the day sanding and priming again.
Yesterday I sprayed one coat of primer and then spread a little filler. Better results are had by applying the filler on the primer instead of first. That way the primer fills the pores of the wood and not the filler so more consistent.
By applying only one coat of primer I fill the pores for the filler and then the thin coat acts like a guide to show if your digging a hole, so to speak. Both the filler and the primer are softer than the Medex, so not completely bad to get some sand through at this stage. But if you had two coats of primer you were sanding through you might have to spend extra time blocking it out so it wouldn’t show.
Anyway, happy with the results today, only minimal defect showing. Maybe a little spot putty here and there before the next sanding. Planning on having ready to spray color next weekend.
Yesterday I sprayed one coat of primer and then spread a little filler. Better results are had by applying the filler on the primer instead of first. That way the primer fills the pores of the wood and not the filler so more consistent.
By applying only one coat of primer I fill the pores for the filler and then the thin coat acts like a guide to show if your digging a hole, so to speak. Both the filler and the primer are softer than the Medex, so not completely bad to get some sand through at this stage. But if you had two coats of primer you were sanding through you might have to spend extra time blocking it out so it wouldn’t show.
Anyway, happy with the results today, only minimal defect showing. Maybe a little spot putty here and there before the next sanding. Planning on having ready to spray color next weekend.
Now in color!
Started my Saturday early with a sander. I should find better things to do here in Hawaii on a weekend!
Before I actually started sanding the primer I sprayed last weekend, I went over the entire surface with a high intensity light and marked all pin holes/defects and then hit with a little glazing putty.
Sanded the entire surface with 600 grit, then a little Cromax rattle can bumper paint on all sand through or glazing putty. Seems a little strange product to use, but it dries quick and keeps the final paint from “flashing” at these spots. Great trick to use on last minute touch ups. The most minute defect gets amplified in the final paint.
Then 2 coats of Cromax automotive paint, through a Sata gun, 1.4 tip, 65lbs pressure.
Turned out really good, next weekend or so I’ll be wetsanding and polishing. With this product you can actually wet sand the next day, but I find the paint is still too soft and makes it harder to polish.
Then ready for assembly!
Started my Saturday early with a sander. I should find better things to do here in Hawaii on a weekend!
Before I actually started sanding the primer I sprayed last weekend, I went over the entire surface with a high intensity light and marked all pin holes/defects and then hit with a little glazing putty.
Sanded the entire surface with 600 grit, then a little Cromax rattle can bumper paint on all sand through or glazing putty. Seems a little strange product to use, but it dries quick and keeps the final paint from “flashing” at these spots. Great trick to use on last minute touch ups. The most minute defect gets amplified in the final paint.
Then 2 coats of Cromax automotive paint, through a Sata gun, 1.4 tip, 65lbs pressure.
Turned out really good, next weekend or so I’ll be wetsanding and polishing. With this product you can actually wet sand the next day, but I find the paint is still too soft and makes it harder to polish.
Then ready for assembly!
Hi
you are lucky to have such great place to make speaker
they must be really great looking..
follow with interest how it goes
I have once again tried my Hypex amp to the 18 "
it does not work here,,my Gryphon amp sound a good deal better in the bass area
(even my wife said it )
i have also change the filter to the 18".....a C-Coil with lower ohm and all film cap
all Janzen component
Best Bjarne
you are lucky to have such great place to make speaker
they must be really great looking..
follow with interest how it goes
I have once again tried my Hypex amp to the 18 "
it does not work here,,my Gryphon amp sound a good deal better in the bass area
(even my wife said it )
i have also change the filter to the 18".....a C-Coil with lower ohm and all film cap
all Janzen component
Best Bjarne
I know this is an obvious question, and apologies in advance if I am teaching Granny to suck eggs, but you did gain match the Hypex and the Gryphon amplifiers, didn't you?
Alex
hi Alex
No problem ..asking
yes i have gain mach,, trying different things--several gain ,,,but there are something that not plays right
i have the same thing with Groundsound filter and amp,,but with my old speaker..2 different amp...it is not me....better with ordinary filter
i am just super happy with my speaker,,,
best bjarne
No problem ..asking
yes i have gain mach,, trying different things--several gain ,,,but there are something that not plays right
i have the same thing with Groundsound filter and amp,,but with my old speaker..2 different amp...it is not me....better with ordinary filter
i am just super happy with my speaker,,,
best bjarne
Could you put your finger on what it was that you found less satisfying with the Hypex amps?
I am interested because my next project will use a couple of Hypex PSC2.400d plate amps to drive 11" woofers. I am aware that there is a latency of a couple of milliseconds in the digital filter of the Hypex (as has been mentioned before on this forum), and this is potentially audible. An analogue filter wouldn't introduce this delay.
Alex
The definition in the bass from Gryphon is better,,,more strong not so rounded..better dynamic ..the sound overall has more coherency
but remember it is not day and night difference
maybe it is because the crossover point at 200hz
i have use the hypex (same as yours) in my brothers speaker,,,30w scanspeak woofer
(those are for sale now ) there the hypex sound really good,,but the crossover was 100hz,,,so is it because the lower crossover ?
but remember it is not day and night difference
maybe it is because the crossover point at 200hz
i have use the hypex (same as yours) in my brothers speaker,,,30w scanspeak woofer
(those are for sale now ) there the hypex sound really good,,but the crossover was 100hz,,,so is it because the lower crossover ?
Thanks for your comments.
Yes it’s great to have access to a shop like this. But a curse too, I wouldn’t take on projects like this without out it. Could take up surfing!
Really interested in your comments about power for the 18”. I have the full crossover components, and am planning on installing in the compartment. But there for later trials.
Your amp puts out 500wpc, so you have the power to run the 18”. I have a strong 100wpc amps, so not a option for my current equipment.
Have you run the Hypex both ways? With DSP and not through crossover, or with DSP off and through the crossover?
i have only tried the hypex with DSP
i have tried a 200w holton amp on the speaker,,,absolute no problem
so i think 100w will drive the speaker very good (remember troels use 60w tube on the top )
only thing to take care of with the amp,,must drive 3 ohm (3ohm impedance about 120hz with passive filter)
i must say ,it is my opinion about hypex or not,,other will maybe say the opposite ,,we all listen different
i have tried a 200w holton amp on the speaker,,,absolute no problem
so i think 100w will drive the speaker very good (remember troels use 60w tube on the top )
only thing to take care of with the amp,,must drive 3 ohm (3ohm impedance about 120hz with passive filter)
i must say ,it is my opinion about hypex or not,,other will maybe say the opposite ,,we all listen different