Monitor 4 upgrades
DeRod
Posts: 229
I had a whole roll of walnut veneer I used on my monitor 7s left over and thought these monitor 4s would look cool with some veneer.
Would also like to do something with the crossovers to try to make these at least half way decent.
"Equality is a myth to protect the weak. Some of us are strong in the Force, others are not. Only a fool believes otherwise." - Sith Proverb.
Comments
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Did they have the Peerless or SL1000's?Don't take experimental gene therapies from known eugenicists.
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@xschop Peerless! I actually have 2 pair, and I think enough veneer to do all 4 speakers.
The crossover is where I'm stumped. Was Polk on purpose trying to make a horrible sounding speaker?
All the other vintage pre 1986 monitors for the most part use a 12uf cap for the hi-pass and the 34uf for the woofer. What's up with this 5.8uf crossover?
There really isn't any difference between these and the monitor 5 except the cabinet dimensions and the port size. I think with a proper crossover the monitor 4 could sound decent.
I got 1 pair stripped naked already
"Equality is a myth to protect the weak. Some of us are strong in the Force, others are not. Only a fool believes otherwise." - Sith Proverb. -
Maybe the Speaker Specialists had some special people in production. Are the baffle faces set evenly on all 4 corners? A couple of the 5 Jr's I built were wonky that way.Don't take experimental gene therapies from known eugenicists.
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The original Monitor 4 was a good sounding loudspeaker, stock.
Actually, I wish I had a pair of 'em... but I digress.
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@mhardy6647 These are absolutely horrible sounding 🤣 I'll gladly sell you these when I finish playing with them 🤣
@xschop all four cabinets seem well built and the front baffle on all 4 are even.
The components are the same in these as the monitor 5 and I have extra set of monitor 5 crossovers so I'm going to try in these to see how that sounds. That makes more sense than the cheesy crossover Polk put in these."Equality is a myth to protect the weak. Some of us are strong in the Force, others are not. Only a fool believes otherwise." - Sith Proverb. -
Also be mindful that some of the MWs in the early monitors were not 6502's.
Looking forward to pics.Don't take experimental gene therapies from known eugenicists. -
So this one and the 5jr were the only ones that were ported in the early lineup. I'm thinking being technically a bass reflex speaker instead of an enclosed but passive radiator one might effect the crossover design. Do you have a picture of the damping material that was in them; I mean how much? Pending further research.......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 -
@xschop they all 4 came with MW6500 but I do have another pair of 6502s and extra pair of 5B crossovers so I could try it out with both ways.
@Gardenstater they all seemed overly stuffed! They all had egg crate material behind the woofer that had melted and turned green all over the crossovers. When I went to pull out the egg crate foam it turned to dust and disintegrated. They also had a wad of poly fill front of the egg foam.
When I try it with the M5 crossovers I’m going to try with and without the foam. Maybe to try to get a little more internal volume."Equality is a myth to protect the weak. Some of us are strong in the Force, others are not. Only a fool believes otherwise." - Sith Proverb. -
@Gardenstater Polk could’ve cared less about crossovers in these speakers. I think they used these like little garbage cans.
Got 200 M10 crossovers left over? Solution - Throw them in the M4! 🤪"Equality is a myth to protect the weak. Some of us are strong in the Force, others are not. Only a fool believes otherwise." - Sith Proverb. -
After you get the crossovers sorted/rebuilt, look into a set of anti-diffraction tweeter pads from @VR3.Don't take experimental gene therapies from known eugenicists.
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@xschop You’ve probably realized from my previous posts I do a lot things backwards. 🤪
And yes @VR3 diffractions pads in my opinion should be considered a standard mod/upgrade to all the old monitors and SDAs.
"Equality is a myth to protect the weak. Some of us are strong in the Force, others are not. Only a fool believes otherwise." - Sith Proverb. -
@Gardenstater that’s what was stuffed inside the cabinets. The original foam disintegrated but I cut that out to the same size. The foam was squished between the magnet and the crossover. The poly fill behind the tweeters."Equality is a myth to protect the weak. Some of us are strong in the Force, others are not. Only a fool believes otherwise." - Sith Proverb. -
I updated mine (MW6500’s and Peerless) a few years ago with Noico on the baskets, glued magnets, acoustic barrier on the back walls, new polyfil, Clarity 5.8uF caps and new binding posts. I really enjoy listening to them. They do lack in the bottom end but when paired with a sub, they’re great.
Current Collection: Monitor 4a (Peerless), Modified Monitor 7b (Peerless), RTA15TL (SL3000), SDA CRS+ (194’s), SDA SRS 2.3TL, R100's, R200’s, R300 🤩 -
You forgot something 🤣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 -
Nice work! I'm following it.
I bought mine a dozen years back. Locally, from the original owner.
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aprazer402 wrote: »
Nice work! I'm following it.
I bought mine a dozen years back. Locally, from the original owner.
That's what I'm talkin' about.
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@JayMX Very nice 👍
Just upgrading the electrolytic cap made no real noticeable difference. There is no bass or lower midrange.
The crossovers marked 1983 are original M4 unmodified, the ones marked 1982 I upgraded the capacitor, the ones with the red caps are upgraded 1981 M5 crossovers.
Going to start cutting the veneer next.
Then back to the crossover experiment.
Post edited by DeRod on"Equality is a myth to protect the weak. Some of us are strong in the Force, others are not. Only a fool believes otherwise." - Sith Proverb. -
Found that in another post. HF1000 = Peerless"Equality is a myth to protect the weak. Some of us are strong in the Force, others are not. Only a fool believes otherwise." - Sith Proverb. -
@Ryan_Soundunited Any chance we could get this schematic posted in the Vintage Speaker section under Schematics (all except SDA)? Probably only the 2nd schematic we have existing of the Peerless days.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 -
HF=Hi Fidelity-1000
SL=Seriously Lacking-1000
Don't take experimental gene therapies from known eugenicists. -
I think I have enough veneer for all four of these and maybe a pair of Monitor 5s as well"Equality is a myth to protect the weak. Some of us are strong in the Force, others are not. Only a fool believes otherwise." - Sith Proverb. -
2 coats of glue for extra stick .. almost ready for the bottoms
"Equality is a myth to protect the weak. Some of us are strong in the Force, others are not. Only a fool believes otherwise." - Sith Proverb. -
Bottoms"Equality is a myth to protect the weak. Some of us are strong in the Force, others are not. Only a fool believes otherwise." - Sith Proverb. -
It seems like you've done this before. Nice workshop lol.
Regarding the crossovers in different size speaker enclosures, using the same tweeter and MW, it seems like baffle size matters, for one thing. Here's some early 78 crossovers for the M5 that had dual fuses and note the tweeter series resistor value of 6.2 Ohms. More than the 4.5 Ohms used in the M7.
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 I was working on them in living room and watching football 🤪"Equality is a myth to protect the weak. Some of us are strong in the Force, others are not. Only a fool believes otherwise." - Sith Proverb.
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I'd agree, that the odd X-over difference is related to baffle step compensation Polk did, due to the small enclosure. More curious if they did anything different X-over wise with the Monitor 4's that accompanied the LF-14?Don't take experimental gene therapies from known eugenicists.
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And it is very interesting that Polk put the tweeter in reverse polarity in the M4, even though, as far as I can see, it is still a 2nd order crossover. But something about the baffle size changed things enough that they needed that to prevent a worse phase cancellation effect around the crossover point.
I think you definitely need to verify tweeter and MW polarities, in case a previous owner chimped that up on you.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 so I could change the 6.2k to a higher value? The one I'm playing around with is the same as that one but a single fuse.
I was thinking something like that as that crossover is basically the same as the 7 with exception of the 6.2k resistor being 4.5k"Equality is a myth to protect the weak. Some of us are strong in the Force, others are not. Only a fool believes otherwise." - Sith Proverb. -
No "k" 😁
Maybe you might want to try that. Maybe if you don't the smaller baffle will result in overly bright tweeter. But then there is the reverse polarity which also comes into play. The diffraction wool pads will tame the tweeter a bit.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 -
Yeh that's the problem with these little speakers. All treble no bass"Equality is a myth to protect the weak. Some of us are strong in the Force, others are not. Only a fool believes otherwise." - Sith Proverb.
