"Old" Monitor 7 any good? (paper coned PR)

2

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  • mhardy6647
    mhardy6647 Posts: 33,786
    SeleniumFalcon wrote: »
    I believe it was done with the tip of a soldering iron.
    That has long been my understanding (belief? ;) ) as well. I am sure there was an SOP. :)
    I think that brochure was created by Al Ballard.
    Well, that's cool.
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  • Gardenstater
    Gardenstater Posts: 4,459
    edited July 2021
    odcics2 wrote: »
    Did the hole cure a ringing issue at a certain frequency?

    Certainly, added cost for no reason would not be justified!

    Or, perhaps, it helped cooling?

    Apparently, it was a band aid, but why?

    I can’t say I’ve heard of any other tweeters with a hole in the middle.
    But, I’ve only been around 65 years!

    There is one extended multiple page audio magazine info advertisement where they, get this, call it an SL1000 and also refer to the hole as "aperture tuning", so I believe it was a tweak and not for air pressure issues from flying. I haven't ever been able to find more. I can see how it might improve transient response by working as a small vent. In lots of tweeters they do other things like add an air chamber behind the dome, with lambswool or the like as absorption material.
    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
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  • pitdogg2
    pitdogg2 Posts: 25,436
    edited July 2021
    Ken should know @SeleniumFalcon. Years ago another Polk employee has said the same about the hole. I've never had the pleasure to remove a dome on the peerless. I do know that both the sl1000/2000 had felt disc's under the polyamide dome. I also know I have seen some non-hole peerless that were wrinkled badly so I think there is much truth to what Ken states.
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  • mhardy6647
    mhardy6647 Posts: 33,786
    edited July 2021
    pitdogg2 wrote: »
    Ken should know @SeleniumFalcon...
    That's a big 10-4. :)
    ... I also know I have seen some non-hole peerless that were wrinkled badly so I think there is much truth to what Ken states.

    Or... or... perhaps little-kid-fingers(?).
    Little kids' fingers seem to be drawn to speaker drivers' domes and/or dustcaps just like BBs are drawn to rural stop signs. ;)B)



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  • Gardenstater
    Gardenstater Posts: 4,459
    For some reason tonight I cannot find the early multi page info ad, but this is the exact quote from it, which I got because I quoted it to geppy1 in a previous thread. I asked him if they were referring to the hole in the silk dome and he replied Yes. Now I know this isn't necessarily the final word but it is worthy of consideration:

    "The dome is vented (aperture tuned) in much the same way that woofer systems are tuned to further smooth out its response curve and improve transient response and power handling"
    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
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  • Gardenstater
    Gardenstater Posts: 4,459
    I found it:

    vq86h4sa0i2w.png
    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
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  • odcics2
    odcics2 Posts: 331
    With the right equipment, hole versus no hole tweeters could be measured to see the difference.
    It would have to be audible or they wouldn’t have added the hole.

    That brings up the question of hole-less later tweeters. Apparently, some tweaks were done so no hole was needed.
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  • Gardenstater
    Gardenstater Posts: 4,459
    edited July 2021
    Yeah. If it's a doped silk dome vulnerability to air travel, one has to wonder why the RDO's didn't have the hole. I have a pic somewhere of a Peerless with the dome/bezel removed and I believe it had a white felt domed disk on the pole piece. @xschop ? (I know he left unfortunately)

    I have a couple Peerless karma'd me by xschop where he re-domed them from Chinese silk domes/voicecoils. When I get around to it ( :# ) I will try burning a hole in one without butchering it and take some before and after spectrum graphs but I don't have a calibrated mic, just a phone app. Enquiring minds (PolkNerds) need to know 🤣

    PS: If you shine a flashlight through the hole in a Peerless, you can clearly see the white felt inside.
    Post edited by Gardenstater on
    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
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  • odcics2
    odcics2 Posts: 331
    edited May 2022
    Any more insight on this thread?

    Talked to the owner of the 2 pairs recently...
    He still has them. What would be a good cash and carry price to offer him for the 2 pairs?
    They are in fair condition.
    Thanks.
    Post edited by odcics2 on
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  • F1nut
    F1nut Posts: 50,537
    Just buy them. Very cool, very early examples.
    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

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  • mhardy6647
    mhardy6647 Posts: 33,786
    edited May 2022
    I mean... I'd like to have a pair -- for completeness, you know?
    ;)

    51294321276_85cf86aa9f_b.jpg
    51294498973_521bb99248_b.jpg
    Post edited by mhardy6647 on
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  • odcics2
    odcics2 Posts: 331
    OK! I contacted him, awaiting a reply...
    I'll update after I can swing a deal on them!
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  • DaveHo
    DaveHo Posts: 3,513
    I'd say $200 for the 4 is very good if operating properly and not beat up. Be prepared to refresh the crossovers if all original.
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  • audioluvr
    audioluvr Posts: 5,582

    That "M" on the inspected by looks strangely familiar.
    odcics2 wrote: »
    izbpydwlcqtx.jpeg

    Gustard X26 Pro DAC
    Belles 21A Pre modded with Mundorf Supreme caps
    B&K M200 Sonata monoblocks refreshed and upgraded
    Polk SDA 1C's modded / 1000Va Dreadnaught
    Wireworld Silver Eclipse IC's and speaker cables
    Harman Kardon T65C w/Grado Gold. (Don't laugh. It sounds great!)

    There is about a 5% genetic difference between apes and men …but that difference is the difference between throwing your own poo when you are annoyed …and Einstein, Shakespeare and Miss January. by Dr. Sardonicus
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  • odcics2
    odcics2 Posts: 331
    audioluvr wrote: »
    That "M" on the inspected by looks strangely familiar.
    odcics2 wrote: »
    izbpydwlcqtx.jpeg
    Why?

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  • F1nut
    F1nut Posts: 50,537
    It would be MP and it's not.
    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

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  • odcics2
    odcics2 Posts: 331
    Looks more like “JM”.
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  • odcics2
    odcics2 Posts: 331
    Just to let you guys know, nothing to report yet. :(
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  • odcics2
    odcics2 Posts: 331
    So, struck a deal on the original 7 and 7a speakers.
    Here’s a couple of pics of the 7s.
    Currently set them on Plateau stands.
    Man, do they sound great. Bass is very extended in my 12x16 room for that small passive radiator. asxnmv2bd2v2.jpeg
    u9hfxdx2yxe5.jpeg
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  • odcics2
    odcics2 Posts: 331
    A few more pics of the 7 back and the 7A speakers that were part of the deal. As you can see, the 7A grilles are BAD. I have posted a WTB ad. wsqla4k4gqtb.jpeg
    ucwixl9x9v0y.jpeg
    ppledagsiui2.jpeg
    79dnckkknlay.jpeg
    gi0au1wrj7uf.jpeg
    iqm57yjtktqf.jpeg
    plmp1slzzxzv.jpeg
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  • Astrl55
    Astrl55 Posts: 64
    edited June 2022
    Just as a point of reference, I see your box has a Wetheredsville Rd address; here's one of my boxes from speakers I bought new in '78 (now on S. Carey St.)

    movazslot6ei.jpg
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  • mhardy6647
    mhardy6647 Posts: 33,786
    edited June 2022
    Neat-o.
    Those The first one is a Model 7 and the second one is an early 7A (similar to my pair), although my pair of 7A are finished in a fetching "rosewood" vinyl finish :#
    Mine also have "dual five-way binding posts" rather than the earlier barrier terminal strip, as exhibited in the photos above. Sorry, I was looking at the wrong speaker in the photos above!

    Plus, the 10" PR is uncoated paper (mine are coated). The original Model 7 had an 8" uncoated paper PR (as shown in the first set of photos). , as most folks looking at this thread would probably know already ;)
    Also, the tweeter isn't holy -- umm, I mean, holey. ;) (mine have the center holes, FWIW)
    So it's either a replacement Peerless or it's before Polk started perforating them.
    All in all, a very, very early pair of 7A, by all appearances.

    fpeuhta75c59.png

    I've posted this image a zillion times, but -- for comparison & FWIW -- here's one of my "rosewood" 7As. :)
    the s/n of this one is 4900.

    10944888976_998ec76e53_c.jpg
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  • odcics2
    odcics2 Posts: 331
    edited June 2022
    My 7A speakers have red glue holding the PR weight.

    I’m curious about build dates on the drivers but want to leave the speakers as is.
    ;)

    Wasn’t the tweeter hole to lessen a peak around 13k ?
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  • odcics2
    odcics2 Posts: 331
    Mhardy: What’s the address on your boxes?
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  • mhardy6647
    mhardy6647 Posts: 33,786
    edited June 2022
    odcics2 wrote: »
    My 7A speakers have red glue holding the PR weight.

    I’m curious about build dates on the drivers but want to leave the speakers as is.
    ;)
    Must be ca. '74 or '75 I would think (a SWAG -- as they say).

    FWIW, I have a pair of Model 10 that have the red racing stripe 'round the PR weight, too. B)
    These 10s have a barrier strip terminal connector instead of binding posts, and (if memory serves) no fuse at all. :| I don' think the s/n card is intact on either one, though (although I haven't looked for a long time).

    11208619575_674f036d9b_c.jpg
    (un-holy Peerless, too ;) )



    Wasn’t the tweeter hole to lessen a peak around 13k ?
    I've "heard" (read) several different hypotheses for the tweeter perforation, FWIW.
    Others here may know for sure, though. Perhaps @SeleniumFalcon knows?



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  • odcics2
    odcics2 Posts: 331
    edited June 2022
    Very cool.
    Yours is the big brother to my 7A. B)
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  • odcics2
    odcics2 Posts: 331
    Question: Would the mid-woofers be the same part number for Monitor 7 and 10 speakers that have Peerless tweeters? (hole or no hole)
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  • odcics2
    odcics2 Posts: 331
    mhardy6647 wrote: »
    odcics2 wrote: »
    My 7A speakers have red glue holding the PR weight.

    I’m curious about build dates on the drivers but want to leave the speakers as is.
    ;)
    Must be ca. '74 or '75 I would think (a SWAG -- as they say).

    FWIW, I have a pair of Model 10 that have the red racing stripe 'round the PR weight, too. B)
    These 10s have a barrier strip terminal connector instead of binding posts, and (if memory serves) no fuse at all. :| I don' think the s/n card is intact on either one, though (although I haven't looked for a long time).

    11208619575_674f036d9b_c.jpg
    (un-holy Peerless, too ;) )



    Wasn’t the tweeter hole to lessen a peak around 13k ?
    I've "heard" (read) several different hypotheses for the tweeter perforation, FWIW.
    Others here may know for sure, though. Perhaps @SeleniumFalcon knows?



    What’s the proper name for the grill attachment hardware?

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  • mhardy6647
    mhardy6647 Posts: 33,786
    edited July 2022
    odcics2 wrote: »
    mhardy6647 wrote: »
    odcics2 wrote: »
    My 7A speakers have red glue holding the PR weight.

    I’m curious about build dates on the drivers but want to leave the speakers as is.
    ;)
    Must be ca. '74 or '75 I would think (a SWAG -- as they say).

    FWIW, I have a pair of Model 10 that have the red racing stripe 'round the PR weight, too. B)
    These 10s have a barrier strip terminal connector instead of binding posts, and (if memory serves) no fuse at all. :| I don' think the s/n card is intact on either one, though (although I haven't looked for a long time).

    11208619575_674f036d9b_c.jpg
    (un-holy Peerless, too ;) )



    Wasn’t the tweeter hole to lessen a peak around 13k ?
    I've "heard" (read) several different hypotheses for the tweeter perforation, FWIW.
    Others here may know for sure, though. Perhaps @SeleniumFalcon knows?



    What’s the proper name for the grill attachment hardware?

    Since 1976 :) I have always heard it referred to as "Super Velcro".
    It's either amazing or the spawn of Satan... depending on whether it's being cooperative or not. ;)

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  • Gardenstater
    Gardenstater Posts: 4,459
    edited July 2022
    odcics2 wrote: »
    My 7A speakers have red glue holding the PR weight.

    I’m curious about build dates on the drivers but want to leave the speakers as is.
    ;)

    Wasn’t the tweeter hole to lessen a peak around 13k ?

    I wouldn't really call this a peak. I think you are probably thinking of the SL2000, although they didn't perforate any tweeters after the Peerless.

    0q6amljfb09v.jpg

    This graph from a NOS Peerless KO10DT box does look a little more peaky doesn't it?

    tyznxc3su66b.jpg

    As far as the hole goes, this is the most definitive info. I have been able to find. Clearly the Peerless although the informational ad refers to it as SL1000:

    wyjt0ilf72bw.jpg


    Post edited by Gardenstater on
    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
    · Share on FacebookShare on Twitter