First off, many thanks to XRK971 for all his advice with the crossover. It would have taken much much longer without his knowledge.
I picked these up 10 years ago at a garage sale for $5 and put them on the shelf. Two weeks ago I thought I'd check them out for garage speakers. The woofer surrounds were blown and I looked everywhere for replacement surround to no avail.
So I found the SB Acoustic SB13PFC25-08 5" Paper Cone Woofer that is a drop in replacement but MUCH better than the stock woofer.
I've built many EconoWaves so I found a 4.5" x 4.5" horn (H45E) that would fit where the tweeter goes and ordered those and the Dayton Audio DT250P-8 1" Polyimide Compression Horn Driver
I used a Linkwitz/Riley 2nd order crossover and added an L-pad made from a 8ohm in series and a 1ohm across + and -. There was still a big bump at 10khz so I added a .47 uf cap in series with the 8ohm and that flattened it out very well.
When I put the woofer through Win-ISD it showed I needed a 1" x 5" long vent and there was no room for that so I order 4 Peerless 830880 Peerless 5.25" Mini Passive Radiator
After listening to the one speaker and very pleased with the sound, I took 40 hours (yes, 40 freakin hours) to sand the case aluminum cabinets and bring them up to a mirror finish.
These are all grits of sandpaper; first 120, then 180, 220, 320, 400, 600, 800, 1000, 1500, 2000, then finally 3500.
Then I buffed with Tripoli, the White Diamond, then Blue, then power polished them with Mothers aluminum polish which also has a wax in it for protection.
I lined the walls with BASF professional grade acoustic treatment foam (reticulated open cell phenolic foam)=(Mr Clean Magic Erasers) to reduce the back wave.
I brought them to a SMAC gathering last Saturday and everyone loved them. They are not bass boomers but for Jazz, Acoustic, Classical, and most rock they sound fantastic.
Here is the real rub......I don't need another pair of speakers. I just got going and this is what I ended up with.
I picked these up 10 years ago at a garage sale for $5 and put them on the shelf. Two weeks ago I thought I'd check them out for garage speakers. The woofer surrounds were blown and I looked everywhere for replacement surround to no avail.
So I found the SB Acoustic SB13PFC25-08 5" Paper Cone Woofer that is a drop in replacement but MUCH better than the stock woofer.
I've built many EconoWaves so I found a 4.5" x 4.5" horn (H45E) that would fit where the tweeter goes and ordered those and the Dayton Audio DT250P-8 1" Polyimide Compression Horn Driver
I used a Linkwitz/Riley 2nd order crossover and added an L-pad made from a 8ohm in series and a 1ohm across + and -. There was still a big bump at 10khz so I added a .47 uf cap in series with the 8ohm and that flattened it out very well.
When I put the woofer through Win-ISD it showed I needed a 1" x 5" long vent and there was no room for that so I order 4 Peerless 830880 Peerless 5.25" Mini Passive Radiator
After listening to the one speaker and very pleased with the sound, I took 40 hours (yes, 40 freakin hours) to sand the case aluminum cabinets and bring them up to a mirror finish.
These are all grits of sandpaper; first 120, then 180, 220, 320, 400, 600, 800, 1000, 1500, 2000, then finally 3500.
Then I buffed with Tripoli, the White Diamond, then Blue, then power polished them with Mothers aluminum polish which also has a wax in it for protection.
I lined the walls with BASF professional grade acoustic treatment foam (reticulated open cell phenolic foam)=(Mr Clean Magic Erasers) to reduce the back wave.
I brought them to a SMAC gathering last Saturday and everyone loved them. They are not bass boomers but for Jazz, Acoustic, Classical, and most rock they sound fantastic.
Here is the real rub......I don't need another pair of speakers. I just got going and this is what I ended up with.
Very nice repurposing of those speaker cabinets, they look great. I am wondering about the 6 - 7dB boost in response between 10 - 15kHz relative to 1kHz, it strikes me that perhaps C3 is responsible for this boost? Is this to compensate for falling response off axis or relatively absorbent room finishes?
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