Monitor 12 Series 2 crossover re-cap advice/help
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^ No ^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 -
Constrained layer damping materials are even better but Polk would've had to fabricate enclosures with 2 layers and the damping mat'l (or elastomeric adhesive) sandwiched in between.George / NJ
Polk 7B main speakers, std. mods+ (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 -
Gardenstater wrote: »Constrained layer damping materials are even better but Polk would've had to fabricate enclosures with 2 layers and the damping mat'l (or elastomeric adhesive) sandwiched in between.
That would have been a huge mistake.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 -
Well by all means please feel free to elaborate.George / NJ
Polk 7B main speakers, std. mods+ (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 -
Terms such as over damped would apply to that and the poster lining the PR area. Both would kill the sound wave/energy transfer to the PR. In addition, many speaker cabinets are designed on purpose with positive cabinet resonances.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 -
I don't think we should just disregard the OP's experience and that of others that adding some thin damping material to the cabinet walls (not acoustical absorption materials) changed the sound for the better. It could be that Polk's choice of 3/4" (maybe 1" in some?) particle board (or MDF) and nothing more was simply a wise business decision based upon cost to benefit ratio. They were very successful at getting a lot of very fine sounding speakers out to the masses and had to be concerned with price and value. Bracing adds stiffness and helps with reducing panel resonance and amplitudes. They certainly saw fit to do that.
Higher end speakers more often than not these days do employ techniques that add a lot of expense and weight to the enclosures, such as multiple layers with constrained layer damping materials sandwiched inside, in addition to extensional layer damping like the OP did.
This is an interesting patent that goes into the construction of a high performance loudspeaker enclosure with the assignee of none other than Sony Corp. This construction would weigh a ton.
https://patents.google.com/patent/US5949033A/en
George / NJ
Polk 7B main speakers, std. mods+ (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 -
Time to add you to my bozo list.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 -
Most inappropriately discourteous sir.George / NJ
Polk 7B main speakers, std. mods+ (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 -
Gardenstater wrote: »I don't think we should just disregard the OP's experience and that of others that adding some thin damping material to the cabinet walls (not acoustical absorption materials) changed the sound for the better.
Wow. I missed a lot while while off in the great Pandemic Time Blur the past 13 months or so...
Hey, George! Nice to meet you.
After living with the 12's in their current incarnation for the past year, I am 100% sure I made the right call with the acousta-mat-style generic stick-on panels on the exposed walls in the lower half of the cabinets.
I had a couple great years of listening to these before they went into storage. So I have a pretty good baseline in my mind for comparison. The differences after the crossover upgrades, tweeter upgrades, and (lastly) the panels are all significant and positive- for me. I did do a little before and after testing with the one side that still worked without the crossover upgrade, so I'd have a refresher, too.
The way the bass behaves is more accurate and really engaging, compared to how it felt boomier and a bit overemphasized in its previous version.
I'm picking up a pair of SDA-1c tomorrow. They need the crossovers rebuilt. And I think I'll end up upgrading the tweeters, too. AND, I'll probably see how the same stick-on panels affect the bass on them, as well. It'll be interesting to see how it affects them. If the panels are a negative, I'll take them out. But, I hope it affects them in the same way it did my Monitors
F1 can call me a blasphemer. That's o.k. He's more knowledgeable about all things Polk than I am, so I respect his thoughts on my travesties. He'll be o.k. if I'm over here drinking RC Cola when he prefers Coke or Pepsi
The Thrifty Setups in Mah House Big thrifty stereo in the basement w/ my custom SDA-1C (built with help from kind forum members) * Beautiful 1966 MCM GE console upgraded w/ Bluetooth, Dual turntable, and Paradigm speakers in family room * Swanky 1980 Realistic system and great TEAC eq with dancing colored lights in the living room * Ye Olde college stereo in the garage -
Root beer.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
