Monitor 7 Baffle Strengthening
joebass3
Posts: 284
I'm in the process of veneering my beat up 7B's and, while I'm waiting for the veneer to arrive, I decided to install hurricane nuts and also the semi rings that I've had laying around for too long. Others have mentioned that the baffle between the MW and passive radiator is possibly a weak point on this model that could use some stiffening up. I made these and was going to just screw them from the inside into the cabinet. I know most here like mods the can be reversed, so no glue! Thoughts? I had the oak scraps and the free time so if it's not practical I have nothing to loose.
Comments
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Nice you beat me to it. Let us know if you hear any improvements!
I will be using a couple round 1" oak dowels in 2 pairs of glued in wooden sockets, like the way a closet rod is supported. If I like what I hear the dowels will get epoxied for good.George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Onkyo A-8017 integrated
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'm in the process of veneering my beat up 7B's and, while I'm waiting for the veneer to arrive, I decided to install hurricane nuts and also the semi rings that I've had laying around for too long. Others have mentioned that the baffle between the MW and passive radiator is possibly a weak point on this model that could use some stiffening up. I made these and was going to just screw them from the inside into the cabinet. I know most here like mods the can be reversed, so no glue! Thoughts? I had the oak scraps and the free time so if it's not practical I have nothing to loose.
Can't hurt.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
This mod cleans up the mid-bass substantially.
Less energy will be wasted exciting the baffle.🙂
Nice method you used to be able to quickly swap and compare too.Post edited by xschop onDon't take experimental gene therapies from known eugenicists. -
My scraps of wood were free, but I had also thought about this as an alternative. It could be easily adjusted for a tight fit and then attached. But would a metal rod be OK? How close is too close to the speaker magnet?
Post edited by joebass3 on -
Stick to the wood.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
A couple more pics with one cabinet finished. Note to self... make sure to put the roll of polyfill in FIRST before installing the wood braces!
About the polyfill. I know it is suppose to be behind the tweeter and mid woofer, but when took the speakers apart the polyfill was rolled up very tightly and at the top of the cabinet. Basically it was mostly behind the tweeter. I rolled it up a little looser to fit behind the mw also.
Also, is a 4"x4" piece of BH5 or sonic barrier still the go to size behind the MW?
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I like the way the screws for the brace members are easily accessible for doing an A/B comparison. Did you glue the semi rings in yet?George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Onkyo A-8017 integrated
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 -
Gardenstater wrote: »I like the way the screws for the brace members are easily accessible for doing an A/B comparison. Did you glue the semi rings in yet?
Yeah I used a 2 part epoxy on the semi rings. -
Gardenstater wrote: »I like the way the screws for the brace members are easily accessible for doing an A/B comparison. Did you glue the semi rings in yet?
Yeah I used a 2 part epoxy on the semi rings.
Bravo. You won't be disappointed.George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Onkyo A-8017 integrated
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 -
Also, is a 4"x4" piece of BH5 or sonic barrier still the go to size behind the MW?
YesPolitical Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
I built the braces for the other speaker today and decided to play around with the placement. It may not make much difference but, since the weakest spot of the cabinet seems to be the middle (between the MW and passive), I was able to get them closer together by about 3/4". I think I'll leave them there.
