FRANKEN-POLK Definition?

F1nut

Gardenstater wrote: »

F1nut wrote: »

xschop wrote: »

VR3 wrote: »

Yes, most of what we do is stuff Polk couldn't do back in the day due to cost or lack of available tech.

Phase plugs have been around a long time and if they wanted to use them I believe they would have for sure, minimal cost difference over a dust cap.

If this is true, why didn't Polk add butyl mat to the baskets before they left the factory?

Dynamat wasn't introduced until 1989, so at the end of the vintage Polk speaker models. Not clear if there was a product like it before then.

"By the 1950s it had become common to increase damping in beams and plates by attaching a secondary
structural or “constraining” layer to the base structure using what was termed as “damping tape" "

This article is interesting but doesn't say when materials like Dynamat went onto the market. Clearly the technology was well known and in practice even in the infancy of Polk Audio.

https://aipp.silverchair-cdn.com/aipp/content_public/journal/poma/19/1/10.1121_1.4800606/4/pma.v19.i1.065023_1.online.pdf

You really had to dig deep for that one...LMAO!

Gardenstater

I found it in seconds LMAO. Search term "history of constrained layer damping" First hit that popped up.

Toolfan66

plastic_avatar wrote: »

From my place on the stage, if you weren't a member of the cool kids' club, you'd have gotten a vigorous rogering from the box seats in the gallery.

---

Some have given me c.r.a.p In their own way, sometimes silence speaks volumes, the difference is I expected it, I get it, and I respect them for it..

Had these been a mint set of Polks?




LMFAO!!!! Bahahahahaha.

txcoastal1

IMHO even if they were mint, the mods were tastefully done in a theme that most people can relate too. They may not go into the main living room due to WAF, but in many cases neither would an all original pair of Monitor 7's.

Gameroom, mancave, garage, office, party room etc

Gardenstater

Toolfan66 wrote: »

plastic_avatar wrote: »

From my place on the stage, if you weren't a member of the cool kids' club, you'd have gotten a vigorous rogering from the box seats in the gallery.

---

Some have given me c.r.a.p In their own way, sometimes silence speaks volumes, the difference is I expected it, I get it, and I respect them for it..

Had these been a mint set of Polks?




LMFAO!!!! Bahahahahaha.

Well one thing for sure, he definitely knows what "full monty" means lol.

Toolfan66

txcoastal1 wrote: »

IMHO even if they were mint, the mods were tastefully done in a theme that most people can relate too. They may not go into the main living room due to WAF, but in many cases neither would an all original pair of Monitor 7's.

Gameroom, mancave, garage, office, party room etc

Yeah, the wife thinks they are pretty cool, and can’t believe how I made them come to be when I told her my idea for them, but they won’t stay in the living room, wife loves the L800’s, and so do I, these will be moved out in another week or so..

ChrisD06

Gardenstater wrote: »

I found it in seconds LMAO. Search term "history of constrained layer damping" First hit that popped up.

To be fair, just because it was invented by then doesn't mean a mass-produced established name-brand became who was willing to wholesale was existent.

I'm sure if Dynamat and it's reputation was available 10 years earlier, we'd have seen Polk at least consider it officially (unless they did!)

Otherwise, they also have a certain budget to meet. I'm sure in the BOM, any free budget would be better suited other places rather than Dynamat for the drivers.

But hey, it exists now! Slap it on the basket and listen away.

xschop

F1nut wrote: »

Gardenstater wrote: »

F1nut wrote: »

xschop wrote: »

VR3 wrote: »

Yes, most of what we do is stuff Polk couldn't do back in the day due to cost or lack of available tech.

Phase plugs have been around a long time and if they wanted to use them I believe they would have for sure, minimal cost difference over a dust cap.

If this is true, why didn't Polk add butyl mat to the baskets before they left the factory?

Dynamat wasn't introduced until 1989, so at the end of the vintage Polk speaker models. Not clear if there was a product like it before then.

"By the 1950s it had become common to increase damping in beams and plates by attaching a secondary
structural or “constraining” layer to the base structure using what was termed as “damping tape" "

This article is interesting but doesn't say when materials like Dynamat went onto the market. Clearly the technology was well known and in practice even in the infancy of Polk Audio.

https://aipp.silverchair-cdn.com/aipp/content_public/journal/poma/19/1/10.1121_1.4800606/4/pma.v19.i1.065023_1.online.pdf

You really had to dig deep for that one...LMAO!

2023 goin' out with a bang....

Gardenstater

The technology of CLD was well known, since the 30s and had become well defined with scientific papers in the 50s (when they referred to it as DAMPING TAPE) so you can absolutely be certain that Polk engineers were well aware of it and fully capable of combining a sticky layer of viscoelastic soft grade of butyl rubber with a thin layer of aluminum. They did after all design the triple layered damping configuration of the midwoofer cones, the outermost layer in fact being a sticky viscoelastic layer in and of itself.

I'm sure that most of their decision making came down to designing the speaker to sell at a certain price point with a desired amount of profit. Could they have incorporated some of these things and sold them successfully at a higher price point and higher performance level? We'll never know.

VR3

IMO, Polk would have designed a proper cast basket before utilize dampening pads. Why bother designing a stamped steel basket and then buying dampening pads and paying someone to apply it then just designing a proper cast basket? Doesn't make much sense is all!

F1nut

Gardenstater wrote: »

I found it in seconds LMAO. Search term "history of constrained layer damping" First hit that popped up.

Like I said, you had to dig deep for that one considering that most refer to the product as butyl mat.

I'm happy owning the brown wiener, much better you owning the brown star. LOL

Gardenstater

There is a lot of expense involved in designing and tooling up for and manufacturing a cast basket. That would have put them in a much higher price point target than they were shooting for, relative to the competition. I think it is quite likely that they didn't design that stamped steel basket but it was probably already tooled up and off the shelf and the same basket design was probably used by other speaker manufacturers.

VR3

Maybe? Polk produced a ton of those drivers.

Definitive did the same thing and these 6.5 midbass had a very nicely designed basket and was used in low cost speakers. They used this exact driver in various parameters for close to 20 years

The way Polk used them across a wide variety of speakers over a long period of time... I don't think the cost is thst different when done in scale.

DarqueKnight

xschop wrote: »

VR3 wrote: »

Yes, most of what we do is stuff Polk couldn't do back in the day due to cost or lack of available tech.

Phase plugs have been around a long time and if they wanted to use them I believe they would have for sure, minimal cost difference over a dust cap.

If this is true, why didn't Polk add butyl mat to the baskets before they left the factory?

F1nut wrote: »

Dynamat wasn't introduced until 1989, so at the end of the vintage Polk speaker models. Not clear if there was a product like it before then.

When I consulted Polk's engineering department, in 1990, about modifications to my SDAs, one of the recommendations was to apply "foam tape" to the driver and passive radiator baskets to damp them. Dynamat was relatively new at that time. The engineer I spoke to (Chris) probably didn't know about it. This is probably particularly true since Dynamat was an automotive product.

I had a long discussion with Chris about where Polk cut corners and about modifications I could make to move my SDAs' performance closer to the design specification. By analogy, the same house blueprint can be implemented with walls of thick cardboard, wood, brick, or steel-reinforced concrete.

My reasons for modifying my audio gear (and motor vehicles) are to enhance a performance benefit or to reduce or remove a performance deficiency.

xschop

@VR3...Didn't the last iteration of Polk's cast frame MW's have cracking issues?

pitdogg2

Gardenstater wrote: »

There is a lot of expense involved in designing and tooling up for and manufacturing a cast basket. That would have put them in a much higher price point target than they were shooting for, relative to the competition. I think it is quite likely that they didn't design that stamped steel basket but it was probably already tooled up and off the shelf and the same basket design was probably used by other speaker manufacturers.

Cerwin-Vega did it......🎤

mhardy6647

But even cast components can ring like a freaking bell if not carefully made (and sometimes damping's still required). The Altec 511B horn is a classic example. We won't even talk about Klipsch's squawkers.




The only Altec components - to date - that I ever bought... and then sold.

Compare the construction of this EMILAR 500 Hz horn (EH500-2) to the nominally 500 Hz 511B. These certainly benefit from mounting to a sturdy baffle, and probably from some damping as well, but they're way better behaved than the 511B.

Jazzhead

^^^
"Klipsch squawkers" lol....

ken brydson

Bet these dampen better than any dynamat...

VR3

xschop wrote: »

@VR3...Didn't the last iteration of Polk's cast frame MW's have cracking issues?

Yes there were many on ebay with broke baskets

nooshinjohn

VR3 wrote: »

xschop wrote: »

@VR3...Didn't the last iteration of Polk's cast frame MW's have cracking issues?

Yes there were many on ebay with broke baskets

Broke Basket Mountain

xschop

Right next to Shifted Magnet Mtn.

Gardenstater

VR3 wrote: »

IMO, Polk would have designed a proper cast basket before utilize dampening pads. Why bother designing a stamped steel basket and then buying dampening pads and paying someone to apply it then just designing a proper cast basket? Doesn't make much sense is all!

Maybe we need to watch that lost episode of Sliders where MP and his engineering dept. made different decisions leading to different outcomes lol.

I know of one company's engineering dept. so far that I have come across that chose to dampen the stamped steel baskets. That is VMPS which was founded by Brian Cheney, and they used Soundcoat sheets. "Driver baskets are damped with Soundcoat sheets to prevent basket resonances from interfering with cone output". I don't know if that was CLD or just regular D. That company has made lots of different products and they are kind of vague about it. Here's the brochure dated April 1989 that I posted on the forum before:

xschop

Reminiscent of the original factory Franken-Polk...

VR3

Vmps was no where close to scale of Polk Audio operation. Not even in the same ball park

gp4jesus

IME at a minimum ALL RTi*/RTi A Series mids & woofer magnets shields** NEED some sort of damping as they ring like bells. CLD*** accomplishes that plus covers the shiny surfaces
*concluded from pictures that they VERY similar to the A series drivers
***just about the easiest tweak to perform, next to doing nothing and can be CHEAP.

12 years ago I unexpectedly heard them** loud and clear during post mod listening.

“But to each their own.”

Happy ‘24

Gardenstater

VR3 wrote: »

Vmps was no where close to scale of Polk Audio operation. Not even in the same ball park

Polk didn't start out big. They got that way as a result of all their decisions; design, implementation, choice of price points, marketing.....etc......

Maybe if they had done phase plugs and the other aspects of the "full monty" (lol) and damping sheets on the outside of the baskets, the higher price point needed would've upset that apple cart, even if the speakers performed better.

VR3

I would say Polk at their smallest was vmps at their biggest

Gardenstater

Gardenstater wrote: »

VR3 wrote: »

Imo, butyl mat is way more labor intensive then utilizing a phase plug. Even if it is pre cut and the material itself is kind of pricey.

Having a cnc machine routing a hole in the magnet pole piece then having a worker put glue on the bottom of a plastic aluminum phase plug and inserting it in a hole is fairly simple.

Say the extra machining and assembly labor time plus machine time and materials cost added up to maybe $20 per driver. If their profit per speaker was $80 previously, now they have reduced their corporate profit by 25%. I know Polk contemplated going public but never did, but if they reported that on their quarterly earnings report, the shareholders would probably sue or something

Correction. Got curious to learn more about the history of Polk and found out that they were publicly traded from 1986 to 1999, when the founders took it back private. Just to set the record straight.

Gardenstater

VR3 wrote: »

I would say Polk at their smallest was vmps at their biggest

Rapid growth shouldn't be confused with not starting small. The rapid growth was a tribute to their business model.

https://www.stylelaser.com.my/product/polk/

"Polk Audio was founded in 1972 by two young graduates of Johns Hopkins University in Baltimore, Maryland. Matthew Polk, a physics major, and George Klopfer, a student of history, had built public address systems for fiddlers' conventions, and the pair decided they would start a business making audio speakers. The new company, which was formed with only $200 in capital, was named after Polk because his name was easier to pronounce. Initially working out of an unheated garage, the two founders set as their goal speakers which would combine the airy, crisp sound of European designs with the bassier, more powerful style of American ones.

The company's initial contract was to build private-label speakers for a Washington, D.C. stereo shop, but when that order was canceled, Polk and Klopfer were left with unsold inventory which they were forced to market themselves. Assisted by new partner Sanford Gross, they redesigned the cabinets and managed to successfully find buyers for their wares. The new company's speakers received a positive response from both consumers and critics, and within a short period of time the partners were able to move the company's operations to a large Victorian house in Govans, Maryland.

In 1976 Polk Audio, now with 12 employees, secured a $75,000 loan from the U.S. Small Business Administration to help increase production, and revenues grew fourfold the next year, to over $1 million. Two additional SBA loans followed. Annual revenues hit $3.6 million in 1980, with the company now boasting over 100 employees and production of more than 1,000 speakers a week. As a measure of its success, Polk was named to Inc. magazine's list of the 100 fastest growing private companies in the United States."