well the one I use says it takes 1 day to completely dry:
DAP ALEX Fast Dry 10.1 oz. Acrylic Latex Plus Silicone Caulk (12-Pack) 18426 at The Home Depot
DAP ALEX Fast Dry 10.1 oz. Acrylic Latex Plus Silicone Caulk (12-Pack) 18426 at The Home Depot
gog12 -
You already have my answers about bracing and about holes.
By the way, I don't recall reading anything about the nature and shape of your enclosure (essential data, duh) - which is why I offered a generic "intuitive" suggestion to use your intuition. And I commented that little holes just don't matter much.
Naturally, my casual approach should not be taken to mean I have no less respect or interesting in reading the sophisticated discussion of materials going on in this thread. (BTW, raising the freqs of resonance shown in those waterfalls makes the bad-sound more audible.)
Now I wonder if those sophisticated posters have evidence for or against my belief that very little holes like little gaps left around exiting wires don't matter much (except maybe for very small sealed enclosures such as the rear-box on horns)... provided they don't whistle!
Ben
You already have my answers about bracing and about holes.
By the way, I don't recall reading anything about the nature and shape of your enclosure (essential data, duh) - which is why I offered a generic "intuitive" suggestion to use your intuition. And I commented that little holes just don't matter much.
Naturally, my casual approach should not be taken to mean I have no less respect or interesting in reading the sophisticated discussion of materials going on in this thread. (BTW, raising the freqs of resonance shown in those waterfalls makes the bad-sound more audible.)
Now I wonder if those sophisticated posters have evidence for or against my belief that very little holes like little gaps left around exiting wires don't matter much (except maybe for very small sealed enclosures such as the rear-box on horns)... provided they don't whistle!
Ben
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Hi Ben,
Since we were talking about subwoofers, "resonances shown in those waterfalls" are all above sub range (<120Hz). If you measure panel losses with contact mics you would get a better picture.
I guess you refer to the old days when a whole of about 12mm (approx. 1/2 inch) was drilled in the back of an IB to release some pressure from the cone. To show you the difference I made a theoretical model for you. It's based on standard 18mm (approx. 3/4 inch) panel thickness, a system volume of 42.88 Litre and a round gap of 12mm diameter.
Since we were talking about subwoofers, "resonances shown in those waterfalls" are all above sub range (<120Hz). If you measure panel losses with contact mics you would get a better picture.
I guess you refer to the old days when a whole of about 12mm (approx. 1/2 inch) was drilled in the back of an IB to release some pressure from the cone. To show you the difference I made a theoretical model for you. It's based on standard 18mm (approx. 3/4 inch) panel thickness, a system volume of 42.88 Litre and a round gap of 12mm diameter.
I don't recall any old days when a half-inch hole was drilled in a sealed box. I do recall some manufacturer with a metal plate and 1/32-like pin-hole.
And I CERTAINLY don't recall any lunatic drilling holes in an infinite baffle to release internal pressure with barometric changes.
Perhaps the fault is mine but I don't know what "above sub range, <120" means or have much sense of what your charts show. But, crabby as I am this moment, I do appreciate your good intentions in replying.
Ben
And I CERTAINLY don't recall any lunatic drilling holes in an infinite baffle to release internal pressure with barometric changes.
Perhaps the fault is mine but I don't know what "above sub range, <120" means or have much sense of what your charts show. But, crabby as I am this moment, I do appreciate your good intentions in replying.
Ben
What gap? What hole? Where? An infinite baffle, once you get to the edge is ALL hole.
It may surprise you to learn, but charts are much clearer to the person who posts them than to the person who tries to read them.
Ben
On one of my favorite drivers for sealed, SDX7, one can see right thru the gap between the voice coil & the pole-piece to the vent holes in the back (so an SDX7 woofer is never really sealed)
dave
Hi Ben,
Sorry, I had the impression you were referring to an old technique, but it seems you didn’t. Anyway, I was trying to explain how in the old days they sometimes drilled a small hole in a closed box to release the pressure at low frequencies. The advantage was lower excursion at low frequencies. It was nothing more than a safety at times when drivers had limited excursion and ‘delicate’ suspensions (and amps often didn't had low-cut filters). To show an example I made a theoretical model that shows the difference between an ideal closed enclosure and the same enclosure with one drilled hole of 12mm.
Early sixties they started to use more advanced techniques like holes at the top of the piston together with a ‘breathing’ (not air-tight) fabric dome. Also some domes had a small hole in their centre. For instance Philips used the fabric dome technique. Later on, the holes in the piston and/or holes in the back of the magnet were mainly used as cooling devices. During the eighties Dynaudio introduced a system of gaps around the edge of the dome and a hole through the back of the driver for both reasons.
If the plots were difficult to read:
Sorry, I had the impression you were referring to an old technique, but it seems you didn’t. Anyway, I was trying to explain how in the old days they sometimes drilled a small hole in a closed box to release the pressure at low frequencies. The advantage was lower excursion at low frequencies. It was nothing more than a safety at times when drivers had limited excursion and ‘delicate’ suspensions (and amps often didn't had low-cut filters). To show an example I made a theoretical model that shows the difference between an ideal closed enclosure and the same enclosure with one drilled hole of 12mm.
Early sixties they started to use more advanced techniques like holes at the top of the piston together with a ‘breathing’ (not air-tight) fabric dome. Also some domes had a small hole in their centre. For instance Philips used the fabric dome technique. Later on, the holes in the piston and/or holes in the back of the magnet were mainly used as cooling devices. During the eighties Dynaudio introduced a system of gaps around the edge of the dome and a hole through the back of the driver for both reasons.
If the plots were difficult to read:
An externally hosted image should be here but it was not working when we last tested it.
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Braces and damping all done German style with measurements
dämmung-und-versteifen
Google translate works for those who find german a challange
dämmung-und-versteifen
Google translate works for those who find german a challange
Sorry to derail the thread, but will it be ok if I put on my sealant after screwing my subs in my box and let the silicone caulk dry with the speakers loaded? I heard that you should wait 12 hours to let the sealant dry before putting in speakers so that they dont get damaged by any chemicals that are put out during the drying process, put I'm just going to put some one the outside of my box, so could my subs get damaged that way? It's a lot easier for me to do it that way so that I dont have to hook up my speakers from inside the box.
Hi,
Silicone gives off vinegar vapours so probably aren't a problem. Other caulks use different solvent like xylene, toluene, mineral spirits or WHY. Those might be a problem, but if you use it on the outside of the box, you should be fine. There are some cheap silicone-acrylic caulks that seem to be pretty much smell free. Maybe look for those.
Silicone gives off vinegar vapours so probably aren't a problem. Other caulks use different solvent like xylene, toluene, mineral spirits or WHY. Those might be a problem, but if you use it on the outside of the box, you should be fine. There are some cheap silicone-acrylic caulks that seem to be pretty much smell free. Maybe look for those.
Great thread! So much nice info.
I've used good 'ol cheap clear bathroom silicone, not very smelly.
But I still like to get 10-20 extra cm's of cable in the box, as long as it won't rattle or anything. It's really nice to be able to get the drivers in and out, especially if you build a box that can be used for several different drivers.
I've used good 'ol cheap clear bathroom silicone, not very smelly.
But I still like to get 10-20 extra cm's of cable in the box, as long as it won't rattle or anything. It's really nice to be able to get the drivers in and out, especially if you build a box that can be used for several different drivers.
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