Anyone have RPGInc products?

[damonrpayne]

In the next couple of weeks I'm looking pretty seriously at getting a couple of RPG Skyline products. I'm pretty sure my measurements are showing me some reflections off the ceiling from my center channel which I will diffuse with these. They are not precisely cheap but I expect it to be worth it. Depending on how things look after this I may be getting some QEDs, they call them "hemmifusors", unless of course DrWho gives me those plans to make them @ home.

[DrWho]

Oh sure, put the pressure on me []

I'm not going to be available to do anything until after this semester...

[Arkytype]

Damon,

When I was living in central Arkansas, I had a great listening room (24' X 14' X 9') for my Klipschorns and center Belle. I used about 20 of the RPG BAD panels spaced about three inches apart (V & H) in two horizontal rows on the long rear wall. The side walls were "treated" with foot-square 4" foam wedges and the ceiling with some fiberglass lay in ceiling panels (2' X 4' X 1") purchased from Lowe's with the finished side toward the drywall.

I too thought about using Skyline panels on the ceiling, but opted instead for three separate 4' X 4' (two 2' X 4' panels butted together) absorbers mounted with the fiberglass exposed. My thinking was that even with a nine foot ceiling, the Skyline panels would only "see" sound at a grazing angle from the three loudspeakers and wouldn't be that effective as a diffusor. They do make for a sexy (audio-wise, of course) wall treatment.

I used a laser pointer (mounted at several angles to cover the nominal 90 X 40 degree dispersion) in each of the three mid range horns and a mirror on the side walls and ceiling to determine the location of the foam and panels. A couple of throw rugs on the tile floor and viola, a great-sounding room. It wasn't bad before the treatment, just a little live for my taste. The BAD panels made the rear wall "disappear" acoustically and the resulting sound field was very neutral to my ears. There were a couple of low frequency modes that needed some diaphragmatic absorption but I moved to NW Arkansas before I could build them. My new home under construction will have a 26-foot wide wall for the horns and Belle with a 24-foot high vaulted ceiling and loft.

As I wrote in an earlier post, Daddy Dee and fini heard this setup a couple of years ago. They might want to comment on what they heard.

See the first link for info on the RPG BAD panel. Unless you are very patient and are willing to drill several hundred holes in a two-foot-square piece of masonite, the BAD panel is probably not a DIY project!

http://www.rpginc.com/products/badpanel/index.htm

The BAD panel hole pattern in my panels are different from the design shown in the patent. When I asked RPG about it, they said my panels were an "improvement" and could be mounted in any orientation as opposed to the design shown in the patent which has to be correctly oriented.

If you want to view the patent drawings on the U.S. patent office website, you'll need to download a special TIFF viewer available free here.

http://www.alternatiff.com/

BAD panel patent # 5,817,992

http://patimg2.uspto.gov/.piw?docid=US005817992&PageNum=0&IDKey=EF02BC575C4F&HomeUrl=http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2%2526Sect2=HITOFF%2526p=1%2526u=%25252Fnetahtml%25252FPTO%25252Fsearch-bool.html%2526r=16%2526f=G%2526l=50%2526co1=AND%2526d=PTXT%2526s1=%252522DAntonio%252522.INNM.%2526OS=IN/%252522DAntonio%252522%2526RS=IN/%252522DAntonio%252522

Here's a link to the Skyline patent. Notice that the commercial RPG Skyline has a 13 X 12 grid with many different cell depths (or lengths). The DIY site below has an ersatz Skyline design using a 12 X 12 grid with only a few cell lengths. If you choose to build your own using anything but balsa wood, keep in mind it will be HEAVY--so mount it on the ceiling using toggle bolts.

Skyline patent # 5,401,921

http://patimg1.uspto.gov/.piw?Docid=05401921&homeurl=http%3A%2F%2Fpatft.uspto.gov%2Fnetacgi%2Fnph-Parser%3FSect1%3DPTO2%2526Sect2%3DHITOFF%2526p%3D1%2526u%3D%25252Fnetahtml%25252FPTO%25252Fsearch-bool.html%2526r%3D23%2526f%3DG%2526l%3D50%2526co1%3DAND%2526d%3DPTXT%2526s1%3D%252522DAntonio%252522.INNM.%2526OS%3DIN%2F%252522DAntonio%252522%2526RS%3DIN%2F%252522DAntonio%252522&PageNum=&Rtype=&SectionNum=&idkey=NONE&Input=View+first+page

Peter D'Antonio has filed for two patents which expand upon his earlier products. Here are the links:

http://aiw1.uspto.gov/.aiw?Docid=20060231331&homeurl=http%3A%2F%2Fappft1.uspto.gov%2Fnetacgi%2Fnph-Parser%3FSect1%3DPTO2%2526Sect2%3DHITOFF%2526p%3D1%2526u%3D%25252Fnetahtml%25252FPTO%25252Fsearch-bool.html%2526r%3D7%2526f%3DG%2526l%3D50%2526co1%3DAND%2526d%3DPG01%2526s1%3D%252522D%252527Antonio%252522.IN.%2526OS%3DIN%2F%252522D'Antonio%252522%2526RS%3DIN%2F%252522D'Antonio%252522&PageNum=&Rtype=&SectionNum=&idkey=697EEF7DFC91

http://aiw1.uspto.gov/.aiw?Docid=20070034448&homeurl=http%3A%2F%2Fappft1.uspto.gov%2Fnetacgi%2Fnph-Parser%3FSect1%3DPTO2%2526Sect2%3DHITOFF%2526p%3D1%2526u%3D%25252Fnetahtml%25252FPTO%25252Fsearch-bool.html%2526r%3D4%2526f%3DG%2526l%3D50%2526co1%3DAND%2526d%3DPG01%2526s1%3D%252522D%252527Antonio%252522.IN.%2526OS%3DIN%2F%252522D'Antonio%252522%2526RS%3DIN%2F%252522D'Antonio%252522&PageNum=&Rtype=&SectionNum=&idkey=2E3DFB7BDBAE

Finally, if you want to roll your own RPG diffusor or Skyline-type panels, here's a cool site for the DIYer. One of the overlooked design elements of the RPG-type diffusors is that the well dividers must be as thin as possible. 1/8" masonite (or possibly sheet metal) should be the maximum thickness.

http://www.mhsoft.nl/default1.asp

Lee

[Tracking Angle]

No doubt MAS knows where to find DIY plans for the QEDs or "hemmifusors." Of course, he would want you to learn the acoustical science and do the proper room measurements needed to implement them.... [8-|] "A little learning is a dangerous thing." Maybe someday I'll find the time and do it right.