I do have a couple 25W dayton exciters. Not sure of the frequency response, I believe they are midrange drivers. Might be interesting to bring them into the mix in some way, though their tonal quality is largely dependent on the material they are placed on, and the position as well.
Has anyone used roof deck felt material as panel/cab damping? I saw someone say it produced good results when fixed with spray adhesive, but it seems pretty thin.
https://www.homedepot.com/p/Warrior-Roofing-15-Felt-Roof-Deck-Protection-406-0/100092007
What about regular foam, or memory foam, mattress pads? Moving blankets? I've heard carpet underlayment can work, but can get a bit pricey unless you can buy it in small quantities.
https://www.homedepot.com/p/Warrior-Roofing-15-Felt-Roof-Deck-Protection-406-0/100092007
What about regular foam, or memory foam, mattress pads? Moving blankets? I've heard carpet underlayment can work, but can get a bit pricey unless you can buy it in small quantities.
I finally got 1 of 4 speakers in. Any recommendations on speaker placement on the cab baffle? I was going to place them evenly in a rectangle, but I'm not sure if there are any other configurations that are known to help reduce unwanted resonances from having them placed equidistant from the edges.
With four drivers of the same size, you are doing a good job of copying the most expensive used console piano, the Yamaha U3. Which has no highs and rather flabby lows, too. There is no accounting for taste, except the statement that pianos are sold by suits & ties to the eyes, not sound to the ears.
My SP2-XT speaker that can sound like a Steinway or Bosendorfer grand, has a 15" woofer and a 2" horn, crossed over at 2000 hz. Bosendorfers have so much high frequency and ping, the thin strings have to be replaced about every 40 tunings.
My SP2-XT speaker that can sound like a Steinway or Bosendorfer grand, has a 15" woofer and a 2" horn, crossed over at 2000 hz. Bosendorfers have so much high frequency and ping, the thin strings have to be replaced about every 40 tunings.
Roger that. Can you give me the cliffs notes on the difference between the two? I know panel braces will help raise the resonant frequency of the panel, so this was going to be my first thing to try. Coincidentally, I was going to also try adding a panel inside at the halfway mark to split the L/R sides (full size cross section). This would be sort of a combo panel/cross brace.
I know this is different from hifi where we might point a flamethrower at the problem to kill all resonances. I've led myself to disappointment going too far too fast and not being able to undo the mess.
I'm kind of thinking leaf springs, and the way they only cover part of the previous one. I did experiments like this once or twice but I can't remember anything useful to add.
The hope would be to have some control over frequency and level. Surely adding a small brace with mass could result in a similar frequency but different Q. In addition to that add tone. Where you put it to break things up.
Putting a brace in the middle is likely to hold the fundamental and odd order resonant modes, leaving the ones with equal amounts of in/out movement for partial cancellation.
Is this a good or bad thing? I was planning on eventually testing with 3 braces, just 2" wide and 3/4" thick plywood. Will just have to do informed trial and error, I suppose.
Distance between drivers right now will be about 36" (only have one driver in). If I end up adding a 3rd and 4th driver, those will be a bit closer together. I plan on adding damping material, I have a question about it a few posts back in this thread.
I was thinking of using either thin memory foam, moving blanket material, or roof deck felt on the panels, in addition to the bracing. Seem like a decent idea?
at 36 inches you could wind up with a notch or a blob in the response at approximately 380 hz all depending on whether the phase info of the stereo channels is different and to what extent.
i may have missed it but just what keyboard are we talking about?
doing what your doing i would explore stereo "width" circuits as those would/could have a significant impact on the perceived sound.
i may have missed it but just what keyboard are we talking about?
doing what your doing i would explore stereo "width" circuits as those would/could have a significant impact on the perceived sound.
What did you use to come up with the 380Hz number? It definitely sounds like there is some mid-high bass resonance, but being that I only have 1 speaker installed right now, it is definitely not from a stereo phase interaction. I think right now it is all from cabinet/room resonance. I may end up treating the room a bit, as well.
Right now Im on the Casio PX-130. But I'm using Pianoteq as a sound source, and I believe it has built-in stereo width control. Its pretty amazing software, models various pianos and mics from scratch, no recordings at all being used.
Wavelength
with only one driver at play then yes it's likely a box resonance, which is why i asked about whether damping is at play.
with only one driver at play then yes it's likely a box resonance, which is why i asked about whether damping is at play.
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sorry another thought if you have a Visaton BG 20 why not use it open baffled?
and if the eventual plan is to use 4 you have so many ways to configure them, top mounting 2 and using the distance to the other two to tune out the mid resonance should be possible,No?
dipoles might be possible!
and if the eventual plan is to use 4 you have so many ways to configure them, top mounting 2 and using the distance to the other two to tune out the mid resonance should be possible,No?
dipoles might be possible!
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Ahh, I see where you were going with that. Did you see my response/question about damping materials?
That is correct.
I did try it without the rear panel/baffle in place, and it seemed to lose some of the "oomph" in the sound. Of course, there are SO many ways to test it, and I only tried it one of those ways, but with the vents in the rear panel, and the box not being sealed tight, and the dampening material I'll be adding, I think it should work well with the rear panel on. But that is my uneducated opinion.
I honestly wouldn't know where to start with using the placement to tune out resonances. I assume it would be in relation to the wavelengths of the resonant frequencies. I've been thinking more now of trying this cab on its back, raised up like a grand piano, with the speakers facing up. If I try this, I would probably recess the front baffle into the cab 8" or so. The thinking here is to mimic the placement of the soundboard in a grand, and also to contain the sound a bit instead of them sitting right on top of everything. At that point I would try removing the rear panel to create a sort of contained open baffle (top/bottom/side panels would still be in place).
A dipole is an interesting idea here, but holy cow, I wouldn't know where to start with designing that, and how that would work out for the player position a the keyboard. That might be a bit too much to chew off, for this first project.
There are just SO many possibilities, and it will definitely take some time to test a variety of them, and get the baffling/dampening in place.
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