Overnight Sensation build

[JavadS]

Javad , what i was taught is that any round over is better than a sharp edge , but the difference between a 1/2" and 1" is very marginal . but like you said it really starts to show up around 2-3" . the small test i did was when i was building my surrounds . i measured before and after the 1/2" round over and there was a difference . unfortunately that was 2 years ago and i have a ton of measurements since making them very hard to find ... i'll keep looking tho .

Yea agreed, I've built about 10 pair of speakers this year all with roundovers ranging from 3/4" min to up to 1.5", so I'm a fan, but there does seem to be some opinions on the importance, I've had some very experienced say what I said above. My goal was to say "it won't make or break it but definitely do a 3/4" if you can", that is my actual position that I overstated the other direction inadvertently

Thanks,
Javad

[Millstonemike]

Ahh, good stuff, I apologize if I spoke incorrectly, ...
Javad

I haven't really looked at everything that's flown by my screen and I'd bet there's lots more results and postulation from various user experiences and tests.

Could it be that a different roundovers tend to affect different frequencies and/or different roundovers affect the diffraction differently on baffles of different dimensions?

And Peter Piper picked a pack ...

And could driver directivity influence results as well?

[PWR RYD]

Yes that is correct Mike. The driver directivity does make a big difference in how much influence the roundover has. A dome tweeter like the silkie that sits very proud of the baffle will project more accoustic energy on the edge verses a tweeter that is recessed in a waveguide or horn.

[Kornbread]

Is this too much dampening?

[Chris Roemer]

no

[JavadS]

Looks good to me, I've had good luck with some light stuffing behind the woofer/s as well to further dampen the back wave.

[Dwight]

Hey Kornbread, just score that cement board 2 or 3 times with a razor knife and crack it over a 2x4, no mess, easy peasy.

[Kornbread]

Hey Kornbread, just score that cement board 2 or 3 times with a razor knife and crack it over a 2x4, no mess, easy peasy.

A masonry blade on the compound miter works wonders, makes nice clean and straight cuts every time. Figured that trick out about half way through cutting the cement board. I do think the expanding poly glue would have worked better at holding the cement panels in place vs construction adhesive.

The thin colorful padding is 1/2" thick carpet padding, then there is 1" thick open cell foam behind each woofer. This was stuff left over from building the house, basically free and serves the purpose.

Just in case something should happen to the crossover it will be recessed in the underside of the bottom pedestal, which should be plenty thick since it needs to raise the tweeter about 3". This means each driver will have about 3' of speaker wire, should I twist all the wires together into one large wire from crossover to driver or just twist the wires for each individual driver keeping the runs separated?

[martyh]

A masonry blade on the compound miter works wonders, makes nice clean and straight cuts every time. Figured that trick out about half way through cutting the cement board. I do think the expanding poly glue would have worked better at holding the cement panels in place vs construction adhesive.

The thin colorful padding is 1/2" thick carpet padding, then there is 1" thick open cell foam behind each woofer. This was stuff left over from building the house, basically free and serves the purpose.

Good call on the 1" Open Cell foam. The open cell properties are invaluable in controlling internal waves - even more so than the carpet pad.

[Millstonemike]

Good call on the 1" Open Cell foam. The open cell properties are invaluable in controlling internal waves - even more so than the carpet pad.

Isn't the carpet pad open cell foam? I've read about denim (recycled) stocked at HD. But I've never seen in the three stores I frequent. Only the recycled foam in Kornbread's box.

[Kornbread]

IMO, the carpet pad is as you said, recycled foam, all kinds of different pieces and types of foam in there. I do know when laying carpet, putting down the pad makes a world of difference in the sound of the room, the 'slap' is muted.

The two different types/thicknesses of padding were on purpose, my reasoning being together they would control a wider range of resonances. ?

[Millstonemike]

IMO, the carpet pad is as you said, recycled foam, all kinds of different pieces and types of foam in there. I do know when laying carpet, putting down the pad makes a world of difference in the sound of the room, the 'slap' is muted.

The two different types/thicknesses of padding were on purpose, my reasoning being together they would control a wider range of resonances. ?

No questions on your implementation. I took the post about thicker open cell foam behind the woofer to mean the thinner stuff wasn't foam. And there's been several posts lauding the recycled denim padding carried by HD but I've never seen it, only the stuff in you used. I was just making sure I wasn't crazy - I'm looking at foam, not denim.

[Kornbread]

Denim insulation is hard to find around here but Lowes and the local hardware store have Roxul, it's supposed to be a better noise suppressor than fiberglass and not itch. Cellulose seems to be more dense and much better at blocking sounds than fiberglass, if I could of thought a way to permanently affix cellulose to the inner walls of the cabinet, I'd have used it.

The dedicated shop listening room had some terrible peaks, using a combination of home made open face fiberglass and cellulose panels, it was possible to somewhat target specific frequency ranges. Only part of the room treatment is visible in the pic, panels also line the side walls. By varying placement, materiel, thickness, and even the distance from the wall mounted to, it became a good listening room. It took a lot of time and work ... if REW had been around back then the job would have been easier. This was my reasoning behind using different types of padding in the speaker cabinet, attenuation of a wider range of frequencies.

For me DIY is about what I can do with what is on hand, easily available, and (champagne on a beer budget,) affordable. It's a good feeling when things go right.

[Millstonemike]

For me DIY is about what I can do with what is on hand, easily available, and (champagne on a beer budget,) affordable.

And I thought it was just me

[Kornbread]

Got a little work done on the build. Let the glue dry, rounded the edges, and hit em' with some 60 grit. I like the way wood feels soft after a rough sanding. One problem, tweeter cutout is about 1/4" overall too large. How's the best way to fix this?