Excellent work!
Do you have the ability to anodize them? I do like the beautiful machine work, but would likely anodize them black.
Yes I do. One member will be doing black. I know they'll be stunning. If I do a set, they'll be red and I'll anodize the MW phase-plug to match for my last set of Jr's that I have good cabinets for.
+1. I was going to ask this, too. I'll take mine in black, please.
Thanks,
John
➀Speakers: Polk1.2tl's (Uber Mods)➁Pre/Amp/DAC: PS AudioBHK Signature & 250, DirectStream➂Cables/IC's: MITS1Bi-Wire/S1 Balanced+Avel Lindberg1000VA "Dreadnought"➃Power Conditioner: PS AudioP15 Power Plant➄Power Cords: Core Power Technologies Gold, DH LabsPower Plus DIY w/NeotechNC-P301 & P311ends➅Streamer: RoonROCK on wifi'd NUC & Uptone EtherREGEN⟿Ω☯☥☮⟿🔊♩♪♫♬♩♪♫♬♩♪♫♬
Just to be clear, the end-user can do the anodizing. I will not be doing post-treatment due to costs and low production numbers.
That said, the brushed alloy will match the stripped X-over plates and the large SDA spikes I'll be making. They won't be your momma's spikes.
Anodising
A local guy in Perth Australia wants 20 aussies ech. About $14 us.
Note: If Matching the plates colour is preferred ,it will be a problem as Different grades of aluminium also = different colour variations
I got the lathe speed down for the large 2.50" diameter billet to match the tweeter plate patina. Also working on the base pad prototype to go with them. The interface will match the spike cone angle perfectly...
Two reported back that they clear everything under 1.2s and 2.3s.... And theyll raise the SDA's by at least 3 inches...
How the hell have I missed this thread till now ! Xcellent !
Probably the same way the stealthy black paint thread has eluded my radar all this time I've been a member lol.
I have not forgotten what Wessmassguy originally asked about either. I looked thoroughly into the SL1000 to RD0 plate design and feel that the smaller curvature needed and the thinner plate required to mate to the cabinet will be WAY too close for comfort near the back magnet inset. They would simply be too weak/flimsy to be worthwhile.
Now that I've dissected two Old-school Peerless plates, I can design a better SL-1000/RD0 billet adapter plate along with matching block-off plates for the 2 tweeter model SDAs.
Thank you, no rush. Can you take an inner cabinet picture of any bracing near/around the Xover opening and top curvature of Passive?
If I go forward with solid 1/4" thick billet plate for the Xover, then no backing plate would be needed for the Xover itself nor a top Passive backing ring I believe. But I still want to design and machine the semi-rings for these SDAs. An FEA analysis would put the flexion right at the top area above passive....We'll see.
I realize you're in no hurry but apologies for not providing this as soon as promised.
*Disclaimer. I'm a proud American that's lived quite a bit abroad. I hate the US measurement system. Fractions suck. Metric rules! Measurements in mm's.
Thru-hole and in-step measured w/a trusty steel ruler. My digital caliper is too short for the larger measurements but was used on the center-to-center measurement.
As requested:
Inner thru-hole (RED): 359.0 mm
Outer in-step (BLUE): 389.0 mm
PASSIVE center-to-center mount holes (YELLOW): 142.11 mm (all holes)
Bonus Measurement-Bottom of internal brace to top of inner thru-hole: 38.58 mm
My guess is the bonus measurement can/will deviate, some, from speaker to speaker as a result of the original assembly process.
Gut pics of brace/XO plate area follow and I provided several to give you different perspectives. FYI w/the pics, since they will look slightly different than other 1.2's, I mounted the uber big 16 mH inductor on the brace and used an oak dowel to support it. Nothing else modified from stock. I also went Dynamat crazy.
Note to self; looks like the front facing side of the cross brace needs a surgical application of Power Grab. Felt fine but appears lacking.
Hope this helps.
➀Speakers: Polk1.2tl's (Uber Mods)➁Pre/Amp/DAC: PS AudioBHK Signature & 250, DirectStream➂Cables/IC's: MITS1Bi-Wire/S1 Balanced+Avel Lindberg1000VA "Dreadnought"➃Power Conditioner: PS AudioP15 Power Plant➄Power Cords: Core Power Technologies Gold, DH LabsPower Plus DIY w/NeotechNC-P301 & P311ends➅Streamer: RoonROCK on wifi'd NUC & Uptone EtherREGEN⟿Ω☯☥☮⟿🔊♩♪♫♬♩♪♫♬♩♪♫♬
Yes, Big help, thank you. If you still have PR out, can you get a center to center of the mount holes diameter on opposite sides if your Steele ruler is long enough?
Thank you for doing this. The brace is plenty far away to install the steel arcs.
Off topic, but if the Black Hole 5 reduces standing waves, why aren't people filling in those deep cross-cuts to the inner cabinets?
The dado's on the inside walls are for breaking up standing waves. BH5 and dacron are to make the cabinet appear larger than it is to the back wave of sound.
The dado's on the inside walls are for breaking up standing waves. BH5 and dacron are to make the cabinet appear larger than it is to the back wave of sound.
My perspective
They just look lile they compromise the structural integrity/stiffness
Good pic of the Xover plate too. I'll be looking into making them thicker 1-piece with integral handles.
This is similar to room treatments where you have Diffusors and you also have Absorbers. Both work to reduce the intensity of reflected sound energy. Polk must've thought this was an effective compromise to using lots of absorbent material. Maybe that would've increased the effective box size and messed up some tuning they were going for.
George / NJ
Polk 7B main speakers, most mods comp. (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Crown D150 amp
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform
In shop today for a while. Starting some audio related work to include custom-clearancing a set of plates for aftermarket black-phosphated Allen head screws someone sent me.... I prefer the factory screws for a reason lol.
Copper Sleeve to be shrink fit onto Pole Piece (Eddy Mod)? Seems pretty large though. Hmmm
Definitely not an Eddy mod. 4.125" diameter would kill Eddy lol...
How about an XSive point-to-point crossover with integrated terminal plates....
100% copper and Sch. 80 plastic. On fence whether to use Power grab or go get the Grey PVC glue. Once it's cured, I'm going to cut 6 channels so any iteration of the Polk Monitors and CRS+ /SDA 2B crossover components will drop in. Not 100% sure how to orient the CRS+ inductors just yet, but the aftermarket ones I have on hand fit with plenty of room for the capacitors.
The channels will allow for multiple choices of point-to-point mounting...
I guess the thinner it is, the easier to solder. Skin effect may be an issue also, especially for the tweeter bands. Maybe 0.062 for the midwoof tracks and 0.037 for the tweeter? Will the adhesive withstand the heat of soldering? PS: Maybe 0.037 everywhere?
George / NJ
Polk 7B main speakers, most mods comp. (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Crown D150 amp
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform
I know the Power Grab will withstand soldering near it when cured. Even if the immediate area gets a little toasty, the 1/2" wide rings that are left won't budge, being 2 circular flat rings sandwiched together...
I'll let set for a couple days to ensure full cure, then use a part-off tool to seperate the channels....
Well, after 24hrs cure time, I went to cut the first trace ring on the end and it spun, exposing a beautiful blue non-cured Power Grab. I cleaned as quickly as possible off the plastic and will use a 2-part epoxy next.
While I had it apart, I took the wall down to .050" and that was pushing the envelope with too much tool push-off. This is indicative of pure copper. I fine machined the ID and will use acetone to wipe down before sealing.....
Comments
+1. I was going to ask this, too. I'll take mine in black, please.
Thanks,
John
That said, the brushed alloy will match the stripped X-over plates and the large SDA spikes I'll be making. They won't be your momma's spikes.
A local guy in Perth Australia wants 20 aussies ech. About $14 us.
Note: If Matching the plates colour is preferred ,it will be a problem as Different grades of aluminium also = different colour variations
Two reported back that they clear everything under 1.2s and 2.3s.... And theyll raise the SDA's by at least 3 inches...
Probably the same way the stealthy black paint thread has eluded my radar all this time I've been a member lol.
I have not forgotten what Wessmassguy originally asked about either. I looked thoroughly into the SL1000 to RD0 plate design and feel that the smaller curvature needed and the thinner plate required to mate to the cabinet will be WAY too close for comfort near the back magnet inset. They would simply be too weak/flimsy to be worthwhile.
Now that I've dissected two Old-school Peerless plates, I can design a better SL-1000/RD0 billet adapter plate along with matching block-off plates for the 2 tweeter model SDAs.
Haven't forgotten...chores took over this weekend. Will get you the measurements in the next few days.
If I go forward with solid 1/4" thick billet plate for the Xover, then no backing plate would be needed for the Xover itself nor a top Passive backing ring I believe. But I still want to design and machine the semi-rings for these SDAs. An FEA analysis would put the flexion right at the top area above passive....We'll see.
I'll try start the prototype spike on CNC next week with 1/4-20 taps. I see there are many thread adapters out there for 1/4-20.
I realize you're in no hurry but apologies for not providing this as soon as promised.
*Disclaimer. I'm a proud American that's lived quite a bit abroad. I hate the US measurement system. Fractions suck. Metric rules! Measurements in mm's.
Thru-hole and in-step measured w/a trusty steel ruler. My digital caliper is too short for the larger measurements but was used on the center-to-center measurement.
As requested:
- Inner thru-hole (RED): 359.0 mm
- Outer in-step (BLUE): 389.0 mm
- PASSIVE center-to-center mount holes (YELLOW): 142.11 mm (all holes)
- Bonus Measurement-Bottom of internal brace to top of inner thru-hole: 38.58 mm
My guess is the bonus measurement can/will deviate, some, from speaker to speaker as a result of the original assembly process.Gut pics of brace/XO plate area follow and I provided several to give you different perspectives. FYI w/the pics, since they will look slightly different than other 1.2's, I mounted the uber big 16 mH inductor on the brace and used an oak dowel to support it. Nothing else modified from stock. I also went Dynamat crazy.
Note to self; looks like the front facing side of the cross brace needs a surgical application of Power Grab. Felt fine but appears lacking.
Hope this helps.
Thank you for doing this. The brace is plenty far away to install the steel arcs.
Off topic, but if the Black Hole 5 reduces standing waves, why aren't people filling in those deep cross-cuts to the inner cabinets?
My perspective
They just look lile they compromise the structural integrity/stiffness
Good pic of the Xover plate too. I'll be looking into making them thicker 1-piece with integral handles.
Polk 7B main speakers, most mods comp. (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Crown D150 amp
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform
Got my attention too.
Harry / Marietta Georgia
Polk 7B main speakers, most mods comp. (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Crown D150 amp
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform
Definitely not an Eddy mod. 4.125" diameter would kill Eddy lol...
How about an XSive point-to-point crossover with integrated terminal plates....
100% copper and Sch. 80 plastic. On fence whether to use Power grab or go get the Grey PVC glue. Once it's cured, I'm going to cut 6 channels so any iteration of the Polk Monitors and CRS+ /SDA 2B crossover components will drop in. Not 100% sure how to orient the CRS+ inductors just yet, but the aftermarket ones I have on hand fit with plenty of room for the capacitors.
The channels will allow for multiple choices of point-to-point mounting...
Polk 7B main speakers, most mods comp. (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Crown D150 amp
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform
I'll let set for a couple days to ensure full cure, then use a part-off tool to seperate the channels....
Go vote for America.
While I had it apart, I took the wall down to .050" and that was pushing the envelope with too much tool push-off. This is indicative of pure copper. I fine machined the ID and will use acetone to wipe down before sealing.....
These came in last night. Very cool!