Monitor 4 tweeter upgrade

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Does anyone know if it fairly easy or possible to upgrade the tweeter on the Monitor 4 from the tri star to silk dome (sL1000/2000 or peerless)?
Background is I have a Monitor 5s (original owner from 1989) in one room and due to size constraints I have monitor 4s in the other room. I have a true A/B comparison. The 5s sparkle and sound incredible. The 4s sound dull. I was thinking giving them the silk dome tweeter would better match the tone between the rooms and give the 4s some life.

Answers

  • Gardenstater
    Gardenstater Posts: 4,281
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    The very early Monitor 4 had the silk dome Peerless tweeter and MW6500 midwoofer. That's the one you want. I see them for sale every now and then. Pretty sure we don't have the schematic for the early one in the archive but if you had that it would be a place to start but you're basically talking about building a speaker from the ground up. SL1000 and SL2000 were not silk domes. I think they were polyimide, basically plastic.
    George / NJ

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  • xschop
    xschop Posts: 4,837
    edited February 7
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    Would be a neat project to convert one of those to a silk dome. What woofer is in there?
    Don't take experimental gene therapies from known eugenicists.
  • F1nut
    F1nut Posts: 50,086
    edited February 7
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    You mean this? 6vet4j2ouawe.jpg

    You can't use a Peerless, SL1000, SL2000 or RD0194-1 in those speakers.
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  • pitdogg2
    pitdogg2 Posts: 24,927
    edited February 7
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    F1nut wrote: »
    Tri star? Post a pic please.

    That is what folks call that little square tweeter with the 3spokes. It may be a mylar tweeter.

    2c88lan9f3hp.png
  • xschop
    xschop Posts: 4,837
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    F1nut wrote: »
    You mean this? 6vet4j2ouawe.jpg

    You can't use a Peerless, SL1000, SL2000 or RD0194-1 in those speakers.

    A fresh set of wet-market Wuhans will drop right in.
    Don't take experimental gene therapies from known eugenicists.
  • Gardenstater
    Gardenstater Posts: 4,281
    edited February 8
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    Looks like some ebay seller had the same idea lol:

    1q9lchsnemxg.jpg

    Somebody else on ebay is selling the tweeters you don't care for. Looks like they are 4 Ohms:

    l70eif98qckm.jpg

    Same seller is also selling the midwoofer which apparently is a MW6502:

    k4kwyqmor6br.jpg

    Crossovers also from same seller. Much simpler than Monitor 5 or Monitor 7 design:

    5m0hsphssjar.jpg

    9fujzkqjgwiz.jpg

    Another ebay seller is selling the early Monitor 4 crossover. If you feel adventurous you could purchase these and then get Peerless and MW6500 and modify the cabinet to fit everything and you may have something sounding like the early one:

    oyxnzkz0krjy.jpg

    adhnkzbdhv4t.jpg




    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
    xschop Posts: 4,837
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    Found this too... I'd suggested rebuilding your crossovers first then add silk domes if you're not happy.

    jlcb2i9g3a7i.png
    Don't take experimental gene therapies from known eugenicists.
  • Bigfunky
    Bigfunky Posts: 4
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    F1nut wrote: »
    You mean this? 6vet4j2ouawe.jpg

    You can't use a Peerless, SL1000, SL2000 or RD0194-1 in those speakers.

    Thank you for your input. I am curious to learn what the limitation is. Is it the crossover specs? Would it be a mismatch of resistance between the new tweeter and existing woofer?
    I don’t have any speaker building experience (but I did serve as janitor as a teenager in an audio store in the 80’s and remember the SRS’s coming in. It left an impression!!) thanks!
  • mhardy6647
    mhardy6647 Posts: 33,355
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    qb00428qgjhg.png
    1) That should be in the "you're doing it wrong" thread.
    2) I would do something like that. :blush:

  • Bigfunky
    Bigfunky Posts: 4
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    Thank you Gardenstater for your input. I appreciate it.

  • Gardenstater
    Gardenstater Posts: 4,281
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    xschop wrote: »
    Found this too... I'd suggested rebuilding your crossovers first then add silk domes if you're not happy.

    jlcb2i9g3a7i.png

    That jives with the earliest schematic in the archives which is for a Model 4A:

    6yw88b76e5r0.jpg
    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
  • Bigfunky
    Bigfunky Posts: 4
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    So it sounds like a total rebuild to improve the sound. (Which might be worth it if it would actually get closer to the 5s). Before I go off on an ebay hunting expedition, can anyone suggest a good sounding bookshelf model from Polk for 2 channels? How are the Tsi100? Monitor 40 Series II? I would love to add another pair of 5s but I don’t have space for them.
  • mhardy6647
    mhardy6647 Posts: 33,355
    edited February 8
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    psyam7nni9da.png

    Pretty sure that those later Monitor 4 variants used the once-ubiquitous, very cheap, and rather awful Audax mylar dome tweeters - as in the Cambridge SoundWorks Model 17s in the photo below.

    20082332145_9068bb39de_c.jpg

    The early Monitor 4 used the Peerless silk dome and was/is a very decent sounding little loudspeaker. As such, the original morph is well worth seeking out, I'd opine.
    If the box size is the same (which I reckon it is), the later ones could be reverse engineered back to the originals, but it would be neither inexpensive nor particularly easy (although not quite onerous, either, other than sourcing drivers) -- not worth the effort, except for audio masochists (and I realize there are a number of them, umm, I mean, us. ;) ).
  • pitdogg2
    pitdogg2 Posts: 24,927
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    Yes Doc, I couldn't remember the manufacturer but yes Audax is correct. Terrible little buggers.
  • Gardenstater
    Gardenstater Posts: 4,281
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    And then there was the last iteration which was the M4 Series II that had the Polk SL1500 tweeter

    ds0wqew8ds4k.jpg

    fb8gf28c1rqt.jpg

    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