No , I actually got ripped for 20$ by the Albany sheet metal dealer and had
a 13 X 14" / 1/8" sheet cut (below). I'm going to cut a 10.5" X 4.5" rectangle
on its left side for the amp.
Your recommendations are quite welcome.
(I'm good - but a little "rusty" 😱 )
OS
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The sheet metal will flex too much with the power you have here. You're better off with 3/4 plywood or MDF. If it doesn't sound dead when you bump it, it will make noise when the speaker is running.
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Are you sure ? I have run the whole deal with the speaker wire running under
the edge of the plate .... and felt very little vibration ??
"Running the whole deal" = nearly sent the woofer out of it's frame !! 😀
-just to see what I was dealing with ... I'm thorough , as well ..
I don't think the Dayton's have any more than .080 , maybe .1" as the plate ??
That might be .160" AL sheet ( a little over 1/8") -dealer gave me a "cutoff" .
OS
I'm more accustomed to sealed boxes (car audio) but even ported will likely make enough pressure to flex that. Usually if there's an aluminum plate on a box it will be an extrusion so it can't flex. The heat sink might help some.
Yes , I'm ported .. not sealed. And I have considered what effect the extrusion
will have on the "flex" of the whole plate.
I've even considered a piece of angle on the non-extrusion side.
I wonder how Dayton gets away with their .080" plates ?
They sell the PMA250/500 for even sealed enclosures (as complete kits) ??
Edit - you have me thinking , I can integrate a hefty piece of bar/angle where my
extrusion bolts to the plate. BTW , I can not flex that .160" plate on my knee AT ALL !
OS
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If you look closely at the Dayton, they bolt the amp to the plate and bolt the heat sink on the other side. No cutout so it's laminated aluminum with extruded fins. Much stiffer design. Your amp will likely have much more power too. Your supply likely won't sag like theirs does.
Dayton's sub amps actually have a box inside the the plate. It almost looks potted. The pictures you are showing is their full range amp. I may be worried about nothing (wouldn't be the first time). One of the speaker gurus here would know better.
Oh , that's what they do ! So they have the .080 + the 1/4" extrusion with
the thermal conductivity going through the whole double plate (extrusion).
That might be a better idea. I could make a template for my extrusion
drillings , drill slightly larger holes for my Sankens + mounting holes
and re-tap for my OPS PCB standoffs.
It would actually be easier to just do the drilling than to make a cutoff
AND do more drilling. The plate would also become a heatsink , as
an added benefit.
OS
Just figured it out .... put the whole amp outside the box.
And the pre - amp , too
The microphonics on that poor IPS (and OPS) might be too much.
I'm sure the preamp won't like the subs vibrations ,either.
If you do that , the main plate can hold everything. Trafo / PS/
control on the inside - all audio on the outside.
The slewmaster can be mounted "flat" with the IPS out on wires.
And the pre-amp can sit next to it (outside ) the case.
Like a plate on top of a plate (by about 2.25"). Just an idea.
OS
And the pre - amp , too
The microphonics on that poor IPS (and OPS) might be too much.
I'm sure the preamp won't like the subs vibrations ,either.
If you do that , the main plate can hold everything. Trafo / PS/
control on the inside - all audio on the outside.
The slewmaster can be mounted "flat" with the IPS out on wires.
And the pre-amp can sit next to it (outside ) the case.
Like a plate on top of a plate (by about 2.25"). Just an idea.
OS
A bit of research .....
Things that are "micro-phonic"
- larger ceramics
- actually silver mica (piezoelectric effect). 🙁
- wires ... maybe?
- and screws (they fall out 😀)
Not MP -
-Large electro's are quite resistant (PS caps).
-Transistors - to a great degree (better than tubes).
- Trafo / bridge
The relays are variable , depending on type.
After reading audiophile "lore" and real apps -
Most of a proposed sub amps components won't "appreciate"
what a large x-max woofer dishes out (ported or sealed) !
Dayton and many Class D plates either use a cheap plastic "dish" to seal /isolate,
or in the case of some Class D's .... just pot the hell out of everything.
PATHETIC -- they just want "good enough" . 😱
Amazingly , it is "el cheapo" Logitech that actually adheres by
these basic microphonic "tricks" , and actually put the whole
control/amp/.EQ on the outside (fully separate from the enclosure).
OS
Things that are "micro-phonic"
- larger ceramics
- actually silver mica (piezoelectric effect). 🙁
- wires ... maybe?
- and screws (they fall out 😀)
Not MP -
-Large electro's are quite resistant (PS caps).
-Transistors - to a great degree (better than tubes).
- Trafo / bridge
The relays are variable , depending on type.
After reading audiophile "lore" and real apps -
Most of a proposed sub amps components won't "appreciate"
what a large x-max woofer dishes out (ported or sealed) !
Dayton and many Class D plates either use a cheap plastic "dish" to seal /isolate,
or in the case of some Class D's .... just pot the hell out of everything.
PATHETIC -- they just want "good enough" . 😱
Amazingly , it is "el cheapo" Logitech that actually adheres by
these basic microphonic "tricks" , and actually put the whole
control/amp/.EQ on the outside (fully separate from the enclosure).
OS
The Klipsch THX system also uses an external amplifier. I wasn't sure why they did that. All their lower end stuff used BASH plate amps. I think their THX subs are the only ones they make that have any substantial output. Maybe they were concerned about vibration there as well.
There must be a solution, as there are many powered PA subwoofers. They are runnig with double 18", with 1-2kW of power, and 130-140dB soud pressure. If they are working properly day by day, the must be good solution...
My PA subwoofer had separated sub-chamber, made by 18mm plywood, to separate the electronics.
Sajti
My PA subwoofer had separated sub-chamber, made by 18mm plywood, to separate the electronics.
Sajti
They are likely using potted class D amplifiers. Potting does wonders around vibration but can cause all kinds of thermal problems and makes the finished product disposable.
The datasheet says they use a field replaceable amplifier module. This also makes me think it's a potted disposable assembly.
And the power supply:
Sajti
An externally hosted image should be here but it was not working when we last tested it.
Sajti
That looks scary! I work for a transport company and have seen the horror stories first hand. I realize these will be in transport racks but I'd be worried about parts being damaged in shipping! I may be over cautious but I think anything with substantial mass needs to be adequately suspended when near a source of vibration.
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