Monitor 7b restoration
Answers
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The crossovers haven't been touched.....should they be? These are a friend's speakers that I'm trying to rejuvinate.....
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Even latex paint is a rubber-like material, that is water based like the PVA surround treatment liquid. Vinyl is an elastomeric material if I'm not mistaken.......the "V" in PVA.
If I was going to try something different than enaldo did, it would be some sort of rubber cement that was thinned out to an extremely low viscosity; much much thinner than silicone RTV rubber, which I wouldn't want to try.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 -
The crossovers haven't been touched.....should they be? These are a friend's speakers that I'm trying to rejuvinate.....
If you have another $400 or so in your restoration budget, I would most definitely do crossovers, binding posts, and internal wiring. All this stuff adds up in $$ but so do the benefits. Electrolytic capacitors are said to have a problem with their electrolyte drying up. Those are probably way past their service life expectancy, for no degradation. The tweeter capacitor is metallized mylar and the bigger cap for the MW is non polarized electrolytic.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 wondering how something like this might work?
https://www.permatex.com/products/gasketing/black-gasket-makers/permatex-ultra-black-rtv-silicone-gasket-maker-5-oz/
HELL 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 -
just waiting for some speaker cloth (Joann's Fabrics item # 0351 4023).
Just my $.02, but if that material is not really speaker grill cloth, I would take a pass. Fabric intended for use as grill cloth has particular properties so as not to attenuate highs, etc.
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Downloaded a 5s sweep tone test file from 20Hz to 20kHz and tested 1" from center of L speaker dome tweeter with R speaker OFF. Looks pretty smooth so I will not be messing with the coating on this tweeter. You could do something like this with your damaged coating tweeter to see if you have any issues. The yellow line is the one to look at. Peak Hold feature on app engaged.
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 -
Had to be away all day.....important business.....catching large trout on dry flies.....you get the picture.
OK, so hell no on the Permatex, I like definitive answers! The speaker cloth is indeed speaker cloth, at least that's the way they have it labeled and others have used it on these speakers from what I have read on this forum and been pleased. Your comments are nonetheless appreciated as I believe you are absolutely correct. The wrong cloth can change the sound in a bad way. And, unlike me, I also know my friend typically has the grill on so that needs to be a consideration for sure. I'll do some more research on it. Thanks.
George, I'm really interested in doing as you suggest and will have to learn how. Any good tutorials out there for how to do it? I have an iPhone 12 Mini. -
George, your suggestions on the crossovers etc. are also well taken. I need to know if there is a way to do this less expensively as, again, I'm doing this for someone else.....can I get by with just replacing the electrolytic caps? Anything else you'd consider really necessary? I'm surprised in a way because of how good they sound, figured the x-overs were probably OK....
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What do you think about using clear water based rubber cement, diluted of course? Or water based polyurethane? Just throwing around some ideas.....
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Had to be away all day.....important business.....catching large trout on dry flies.....you get the picture.
OK, so hell no on the Permatex, I like definitive answers! The speaker cloth is indeed speaker cloth, at least that's the way they have it labeled and others have used it on these speakers from what I have read on this forum and been pleased. Your comments are nonetheless appreciated as I believe you are absolutely correct. The wrong cloth can change the sound in a bad way. And, unlike me, I also know my friend typically has the grill on so that needs to be a consideration for sure. I'll do some more research on it. Thanks.
George, I'm really interested in doing as you suggest and will have to learn how. Any good tutorials out there for how to do it? I have an iPhone 12 Mini.
I do get the picture, being a fly tier lol! What kind of hatches do you have where you are this time of year? Been several years since I fly fished sigh.
First you will have to find a spectrum analyzer app that works on your phone and that has good features that you like. Mine lets me do peak hold and lets me take a screenshot of the test and then, if I take notes keeping track of what test was under what exact conditions, I can move those screenshot files to my computer and rename the files to something descriptive. A little cumbersome.
You need some way to play digital files. I have the Squeezebox Touch and it will play any files on my computer through the Logitech Media Server software on my computer.
The files I have been downloading from a free site which is fantastic. This is the sweep tone generator that you can set and then download the file. I did a 5 second one that goes from 20 Hz to 20kHz and disabled the logarithmic. Worked well for the first time I tried it.
Link for the sweep tone file generator and download
https://www.audiocheck.net/audiofrequencysignalgenerator_sweep.php
I use Advanced Spectrum Analyzer Pro which only works on Android phones so you have to find one for your phone.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 -
What do you think about using clear water based rubber cement, diluted of course? Or water based polyurethane? Just throwing around some ideas.....
I guess I'd say I feel more comfortable using the same type stuff that enaldo used. I would probably be inclined myself to try the one I gave the link to. I'd try it on something else first and see how it dries and applies in a thin film with a very soft brush. There is something to be said for his before and after freq resp graphs for verification on the Audax tweeter and the other one that he also tried it 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 -
George, your suggestions on the crossovers etc. are also well taken. I need to know if there is a way to do this less expensively as, again, I'm doing this for someone else.....can I get by with just replacing the electrolytic caps? Anything else you'd consider really necessary? I'm surprised in a way because of how good they sound, figured the x-overs were probably OK....
It would be very inexpensive to replace the electrolytics with new electrolytics. I've never heard of anyone doing it so it would be interesting to see if you heard a difference.
Do these speakers have a tweeter fuse? That often benefits from cleaning with some crocus cloth or the like. Very fine sandpaper like 1500 grit.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 -
Yes they do have a fuse, not sure if it is dedicated to the tweeter or the entire system. It is on the back panel just above the connectors....and yes, it definitely needed cleaning which I did, also with deoxit and they're fine now. Before I did that though, there was definitely a problem with signal dropping out and I was worried that my other work may not have succeeded, but was happy to realize it was just oxidation on the fuses.
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Yes they do have a fuse, not sure if it is dedicated to the tweeter or the entire system. It is on the back panel just above the connectors....
Tweeter circuit only then. Some earlier speakers than mine (much earlier) had 2 fuses. One for tweeter and one system.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 -
Hahaha! You wouldn't believe the hatches! All midges this time of year in the upper flats, and tiny ones at that.....probably size 24-28 but what happens is they form clusters, some the size of half dollars, and the trout just gulp them down! Right now this time of year, tailwaters are the ticket and mine is the San Juan River below Navajo dam, 45 minutes from the house. See here (all fish returned to the water unharmed, maybe some bruised egos, barbless hooks used exclusively, first is a good buddy, second my son, third is the midge cluster imitation I tie on Tiemco 101 hook size 22):
Sorry, off-topic but since you mentioned you're a fly-tier I thought you might be interested and get your butt back on the river! I would imagine it comes as no surprise that I'm "Fishead" over on the AudioKarma site.....
Re-read all the posts and the links and have more questions than answers but it's all good.....learning. So, evidently, the coating is there to provide at least in part for the dome to be airtight but that is somewhat misleading as Peerless actually put a hole in the center, which would portend that perhaps an unknown volume of air is intended to escape the dome, perhaps as a way of regulating the volume based on the size of the hole in an effort to optimize the pressure required? Hey, I really am just guessing again here.
Post edited by Anovak on -
Nice Trout! A couple of them would be going home with me. Its been a long while since I've caught any.
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Peerless actually put a hole in the center
Nope, Polk did it with the tip of a soldering iron.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 -
Jesse, I did not know that! I thought it was put there by the manufacturer.....why the heck would Polk do that? All I can think of is so that people can pull the dome back out after someone put their finger in it and pushed it in!!! I had to do that with these two, although after I pulled them apart I was able to "massage" them back to a more perfect dome from the back. Thanks for the clarification/correction amigo. These things are going to be back in rare form once I get done with the help from all who have been so kind on this forum.
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Hey pitdogg2, thanks for the kind words.....I no longer keep fish, strictly a catch and release person these days but yeah, I would imagine they would be kinda tasty! In any case, you would only be keeping one as that is the limit on these waters and they have to be 20 inches, which is no problem here because I usually land at least 4-5 that are that size each time out!
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Jesse, I did not know that! I thought it was put there by the manufacturer.....why the heck would Polk do that? All I can think of is so that people can pull the dome back out after someone put their finger in it and pushed it in!!! I had to do that with these two, although after I pulled them apart I was able to "massage" them back to a more perfect dome from the back. Thanks for the clarification/correction amigo. These things are going to be back in rare form once I get done with the help from all who have been so kind on this forum.
several theories....
tuning and pressure for flight to other countries are some I've seen tossed around.Hey pitdogg2, thanks for the kind words.....I no longer keep fish, strictly a catch and release person these days but yeah, I would imagine they would be kinda tasty! In any case, you would only be keeping one as that is the limit on these waters and they have to be 20 inches, which is no problem here because I usually land at least 4-5 that are that size each time out!
I'm mostly that myself rarely keep any.. But damn Rainbow are tasty and the farmed kind don't do it justice. and yes completely understand and am for limits!
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Crossover cost = 3 tiers (low, mid, high)
low cost = I went Dayton on my Monitor 12 because I had X amount of money. Results? Fantastic, except for a little detail/separation at a certain frequency (and I don't know if it's the parts or the traits of a 30-yr-old speaker). Opinion? If you can't afford more, the Dayton parts are better than those old bits. You'll be pleased.
mid cost = I went Clarity (at the recommendation of a few experts here) for my 1C. I had the money, so I did the best I could. Will be able to report soon.
high cost = If you have the money, go for it. Get those Sonicaps or high-end Jantzens or...
I say it is 100% worth doing on any vintage speaker I wanted to keep.
Regardless, all are an improvement
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 * custom 5B on a system for my Dad * Ye Olde college stereo in the garage -
Jesse, I did not know that! I thought it was put there by the manufacturer.....why the heck would Polk do that? All I can think of is so that people can pull the dome back out after someone put their finger in it and pushed it in!!! I had to do that with these two, although after I pulled them apart I was able to "massage" them back to a more perfect dome from the back. Thanks for the clarification/correction amigo. These things are going to be back in rare form once I get done with the help from all who have been so kind on this forum.
According to Polk advertisement: "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"
But then they go and call it an SL1000 which they later assigned to a design of their own to replace the Peerless lol. I've never seen them call it a Peerless, which it was. Sometimes it was referred to as HF1000.
PS: Pretty envious of your trout fishing opportunities there! Here in NJ the only way you experience that is to be a member of a private fishing club that stocks a stretch of heavily posted water. Sigh.
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 -
Thanks for the further clarification. You, again, da man!
Sorry to hear that you don't have such fly fishing opportunities there in NJ....I moved to this part of the country especially with those activities in mind. Growing up in Germany, I do understand the dilemma though because much of that country's best fly fishing is on privately leased waters. We were very fortunate, however, and had some friends who were landowners of very large tracts with excellent trout waters flowing through. There was where I spent my youth throwing flies to some beautiful fish in settings beyond compare! The Lauterach was the stream I learned fly fishing upon......ahhhh......those are some very warm memories amigo! -
The end result! They will be leaving here in the near future but I've been having some real fun playing them. Magnets/voice coils on the mid-bass speakers re-aligned and epoxied (thanks to all for the guidance and especially to lawdogg for the totally selfless act of sending me a new magnet....free!!!), voicecoils re-aligned on the tweeters and cleaned, grill pegs replaced, new grill cloth from Joann Fabrics (yes, it is the real deal and very, very transparent sounding, at least to me, and CHEAP!!! I am given to recommend it), and played now for a few days to ensure QC is spot-on.....
A few pictures for your kind efforts:
I was blown away by these little guys, and while they lacked some of the fullness, svelte and sophistication of the larger Infinity Quantum 4s, they did not leave a ton on the table in comparison. I was struck by the bass folks, this really surprised me and when I moved them to the floor it only got better! I knew, of course, that stacking them was not the most ideal way to get full bass response from them but I just had to listen to the sound of all 4 speakers running at the same time which was stunning....yes, that's the best word to describe the sound.....stunning!!! I digress, and am known for such, but I have a feeling my friend is gonna be one happy camper!!!
Many thanks again to all on this very wonderful forum. I went into this knowing practically nothing and here we are, a few months later (primarily because it took Joann Fabrics over 6 weeks to get the fabric in) with a result I am so pleased with. So appreciative, amigos, so appreciative!
Happy listening!
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@Anovak
Hey, you have a link for the fabric you used?
Seems I need some, and I'm searching for options today
And the speakers turned out great. Well done.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 * custom 5B on a system for my Dad * Ye Olde college stereo in the garage -
I believe this is what he used. I searched it and bookmarked it when anovak first made mention.
https://www.joann.com/utility-fabric-black-speaker-cloth/3514023.htmlGeorge / 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 -
Hey guys, that is indeed the right fabric......exactly what I used. What you will find is that it is a bit less heavy than the original but goes on nicely provided you get it stretched properly and straight so you avoid having any waviness. I had to play with it for a while but eventually found just the right way to get it on there. You will only need 1/2 yard if you are doing the Monitor 7 speakers, so for $5 and change you are good to go. It took a while but finally they're done. As stated, I had to wait a long time for my local Joann store to get the fabric for me as they were sold out when I first went in there. You can't order it either, even if you were willing to pay for 2 yards as that is the least amount of material they will sell by order (at least for this variety) plus shipping. I was in no hurry, so just hung in there and they finally came through....
Thanks for the compliment, @plastic_avatar.....I'm no pro but I think my buddy will appreciate them considering how they were when I got them and most importantly, they were prone to failure as the magnets were shifted on both of the mid/bass drivers.
