http://www.vikash.info/audio/xls10/
I have to replace the sub amp with another model, the one he specifies is not available in NA. Would I need one that has a plastic cover over the internals?
Thanks, Brendan
I have to replace the sub amp with another model, the one he specifies is not available in NA. Would I need one that has a plastic cover over the internals?
Thanks, Brendan
If you have average to good woodworking skills, yes, this is a good beginner project. If you are unsure about your woodworking skills, a sealed design would be easier.
You could swap the amplifier for another one, no problems. No need for a plastic cover, just check if the amplifier is fully sealed and correct the design for the amplifier size differences.
Some plate amplifiers without rear covers are fully sealed, some are not. It's really important that you have no air leaks at all, since this is a passive radiator design.
You could swap the amplifier for another one, no problems. No need for a plastic cover, just check if the amplifier is fully sealed and correct the design for the amplifier size differences.
Some plate amplifiers without rear covers are fully sealed, some are not. It's really important that you have no air leaks at all, since this is a passive radiator design.
The only thing which would be even easier is a closed box, i.e. the same thing just without the passive radiator. A PR box is in its essence like a bassreflex, so you get a few dB more output around the low cutoff but need a highpass filter, because below a certain frequency the excursion gets very high. Closed boxes are more error insensitive and have a slightly better sound quality, but less maximum spl.
cyberspyder said:
Any air leak will introduce lots of unwanted noise and huge loudness loss. It also mess with the enclosure volume, the enclosure looks larger to the driver so the tuning point is messed up. Even if the leak looks like negligeable, it's not.
It needs to be totally fully perfectly sealed. You can achieve it with caulking inside the enclosure. After the box was fully built and glued, I personally achieved a perfect joint by using excess wood glue, until I got a perfect inner joint on all the inside. (Yes, I'm crazy)
For sealing the amplifier and the driver, you can use some double sided adhesive weatherstripping, or some caulking. Some drivers and amplifiers already come with a strip of foam, that when screwed down, it seals itself.
As richie00boy said, doubling the walls won't help you much. The box will only be much heavier and also it will be a bit bigger. If you want to countersink the driver on the other hand, you could double up the baffle. Countersinking ain't that useful for subwoofers, unless you like the aesthetics of it.
If you have good woodworking skills, go for it. I built my first subwoofer with a basic jigsaw, a drill, a table saw, sand paper and patience. With a circle jig and a router, it will be easy for you.
Good luck !
OK, yesterday I was just 'thinking out loud' when I posted my concern, but I found it hard to believe one of our moderators wouldn't do a performance update to such a meticulous presentation if it didn't work well, so out of curiosity I used Adire's downward sag math to calc/confirm it and found that the published 'Cms' is listed as mm/N for both driver and PR, but is in m/N.
Corrected to mm/N:
830452 = ~0.69 mm = ~5.52% sag
830841 = ~1.99 mm = ~9.05%
Adire recommends < 5%, so if you accept their math and I didn't screw up (a real possibility, so someone please double check it), then the driver may/may not be OK in a down firing app depending on how hard it's likely to be driven, but the PR is a no-no if driven hard. Regardless, I asked Vikash to give his thoughts/real world experience since IMO this is the final arbiter of what's acceptable.
GM
Corrected to mm/N:
830452 = ~0.69 mm = ~5.52% sag
830841 = ~1.99 mm = ~9.05%
Adire recommends < 5%, so if you accept their math and I didn't screw up (a real possibility, so someone please double check it), then the driver may/may not be OK in a down firing app depending on how hard it's likely to be driven, but the PR is a no-no if driven hard. Regardless, I asked Vikash to give his thoughts/real world experience since IMO this is the final arbiter of what's acceptable.
GM
Although my initial intention was to down fire the active driver (for aesthetics), it's only been used side firing both drivers as the project was never fully completed.
Unfortunately I still haven't got round to measuring the FR hence the lack of website updates.
FYI I recall doing the Adire sag calc during the initial design and ending up with the same conclusion - hence the design.
Unfortunately I still haven't got round to measuring the FR hence the lack of website updates.
FYI I recall doing the Adire sag calc during the initial design and ending up with the same conclusion - hence the design.
cyberspyder said:
Put the passive radiator facing the side or rear with the driver facing front. The project looks really good and bass production should be excellent for the size.
Also, a similar project is here. Well worth reading through this anyway, as it is very informative. The author is a member here also.
Hmm, WinISD Pro's HELP file seems plenty good enough to get you going and asking specific questions when you can't figure something out will generally get more attention. I normally don't use it, but one nice feature is that hightligthing a field such as box volume (Vb) or vent length can be scrolled with the arrow keys while you watch the response/whatever plot change.
GM
GM
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