Monitor 7 Driver issues

Hey guys. Grabbed a pair of monitor 70s with stands for $30 this weekend at an estate sale.

I have a Pioneer SX-850 powering them. When volume is low, no issue. However when turning it up, there is distortion from the drivers.

What would cause this?
Crossovers?
Both drivers shot?

I tried another amp and issues is still there.

Comments

  • txcoastal1txcoastal1 Posts: 10,844
    Bust them open, do you have a meter?

    Look a crossovers first for signs of damage. Mids and woofers next scratchy when you push gently on them. How are the tweeters? Put your ear on them when playing music.

    If any of the drivers are good from these tests move to one of the speakers to see if you can get one good speaker

    Process of elimination
    2-channel: Modwright KWI-200 Integrated, Dynaudio C1-II Signatures
    Desktop rig: LSi7, Polk 110sub, Dayens Ampino amp, W4S DAC/pre, Sonos, JRiver
    Gear on standby: Melody 101 tube pre, Unison Research Simply Italy Integrated
    Gone to new homes: (Matt Polk's)Threshold Stasis SA12e monoblocks, Pass XA30.5 amp, Usher MD2 speakers, Dynaudio C4 platinum speakers, Modwright LS100 (voltz), Simaudio 780D DAC
  • F1nutF1nut Posts: 43,618
    Monitor 7 or 70?
    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

  • rmetz85rmetz85 Posts: 14
    txcoastal1 wrote: »
    Bust them open, do you have a meter?

    Look a crossovers first for signs of damage. Mids and woofers next scratchy when you push gently on them. How are the tweeters? Put your ear on them when playing music.

    If any of the drivers are good from these tests move to one of the speakers to see if you can get one good speaker

    Process of elimination

    A voltage meter? Yes. Not sure what I am looking for or what to test. Visually crossovers look fine.

    Tweeters sound great. Drivers do sound a little scratchy when pushing on them with 1 finger. When with two (at 3&9) it pretty quiet until you almost max out. Both speakers are having the same issue. The right may be a little worse than the left.
  • rmetz85rmetz85 Posts: 14
    F1nut wrote: »
    Monitor 7 or 70?

    7s. Phone must have autocorrected
  • rmetz85rmetz85 Posts: 14
    Really nice shape. However very frustrating. Am I cranking them too much? The tweeter has no issue with the volume. I feel these should be able to go even louder. ik3dik2xqc56.jpeg
    mrazcu1kv1cs.jpeg
  • mlistens03mlistens03 Posts: 2,675
    Pull out the drivers and see if the smell a little smoky. if they don't, then my guess is that the magnets have slipped on those drivers, which you can fix with the guidance of others here on the forum.
    Not Tom or Trey or Jim just Micah
    KEF Q150s, NAD 1155 preamp and 4155 tuner courtesy of DaddyJT, NAD C352 playing power amp, BJC Belden cables, Technics SL3200, Marantz CD6004 courtesy of Clipdat, Salamander Archetype rack, Millenium Falcon :)
    I've always thought the goal of high-end audio was not to have your neighbors bang on the wall and say, 'Turn that darn music down' but to have your neighbors bang on the wall and say, 'Tell your friends to go home and you can practice later this week'.

    Resident Child of Club Polk
  • codycatalistcodycatalist Posts: 2,617
    rmetz85 wrote: »
    txcoastal1 wrote: »
    Bust them open, do you have a meter?

    Look a crossovers first for signs of damage. Mids and woofers next scratchy when you push gently on them. How are the tweeters? Put your ear on them when playing music.

    If any of the drivers are good from these tests move to one of the speakers to see if you can get one good speaker

    Process of elimination

    A voltage meter? Yes. Not sure what I am looking for or what to test. Visually crossovers look fine.

    Tweeters sound great. Drivers do sound a little scratchy when pushing on them with 1 finger. When with two (at 3&9) it pretty quiet until you almost max out. Both speakers are having the same issue. The right may be a little worse than the left.

    Scratchy with one yeah because your not applying even pressure so it could sound like the VC is rubbing. Try 3 or 4 points of even pressure, you don't have to push hard just move it back and forth and listen for any scratching. Do they move freely when pushing the driver or does it give you some resistance?
    Just a dude doing dude-ly things

    "Temptation is the manifestation of desire which equals necessity." - Mikey081057
    " I have always had a champange taste with a beer budget" - Rick88
    "Just because the thread is getting views don't mean much .. I like a good train wreck doesn't mean i want to be in one..." - pitdogg2
    "Those that don't know, don't know that they don't know." - heiney9
    "Audiophiles are the male equivalent of cat ladies." - Audiokarma Member
  • FestYboyFestYboy Posts: 3,814
    Better yet, use the passive to displace the MW. Pressure will be absolutely even at all points on the cone.
  • rmetz85rmetz85 Posts: 14
    mlistens03 wrote: »
    Pull out the drivers and see if the smell a little smoky. if they don't, then my guess is that the magnets have slipped on those drivers, which you can fix with the guidance of others here on the forum.

    No scent of smoke. They look nice to be honest. How would I know if the magnet slipped? fdr28kekc2lx.jpeg
  • mlistens03mlistens03 Posts: 2,675
    rmetz85 wrote: »
    mlistens03 wrote: »
    Pull out the drivers and see if the smell a little smoky. if they don't, then my guess is that the magnets have slipped on those drivers, which you can fix with the guidance of others here on the forum.

    No scent of smoke. They look nice to be honest. How would I know if the magnet slipped? fdr28kekc2lx.jpeg

    I don’t have first hand experience with these speakers, but it is a known problem with them. See if you can slide the magnet SLIGHTLY (don’t want to damage the voice coil) and if you can, then the magnet says slipped. I believe the next step after determining that they slipped is removing them and reattaching with red loctite. Before you try any of this, have someone more knowledgeable about these speakers than me comment about this, because I’m no true 100% sure.
    Not Tom or Trey or Jim just Micah
    KEF Q150s, NAD 1155 preamp and 4155 tuner courtesy of DaddyJT, NAD C352 playing power amp, BJC Belden cables, Technics SL3200, Marantz CD6004 courtesy of Clipdat, Salamander Archetype rack, Millenium Falcon :)
    I've always thought the goal of high-end audio was not to have your neighbors bang on the wall and say, 'Turn that darn music down' but to have your neighbors bang on the wall and say, 'Tell your friends to go home and you can practice later this week'.

    Resident Child of Club Polk
  • FestYboyFestYboy Posts: 3,814
    Typically when a magnet slips, the VC gets locked in place. Also, it's difficult to tell by just looking (I made that mistake once... It looked shifted because the magnet wasn't centered on the pole plate. Turns out it doesn't have to be centered: there's tons of clearance at the ID of the magnet).
  • rmetz85rmetz85 Posts: 14
    rmetz85 wrote: »
    txcoastal1 wrote: »
    Bust them open, do you have a meter?

    Look a crossovers first for signs of damage. Mids and woofers next scratchy when you push gently on them. How are the tweeters? Put your ear on them when playing music.

    If any of the drivers are good from these tests move to one of the speakers to see if you can get one good speaker

    Process of elimination

    A voltage meter? Yes. Not sure what I am looking for or what to test. Visually crossovers look fine.

    Tweeters sound great. Drivers do sound a little scratchy when pushing on them with 1 finger. When with two (at 3&9) it pretty quiet until you almost max out. Both speakers are having the same issue. The right may be a little worse than the left.

    Scratchy with one yeah because your not applying even pressure so it could sound like the VC is rubbing. Try 3 or 4 points of even pressure, you don't have to push hard just move it back and forth and listen for any scratching. Do they move freely when pushing the driver or does it give you some resistance?

    I’d say pretty free. Not locked up at all.

    I’m wondering if I’m just pushing them too hard. With bass off, I can really crank it and the tweeter gets annoying loud. It’s like the driver isn’t keeping up with it.
  • VSAT88VSAT88 Posts: 725
    Push Test ? 3 seconds ???
  • codycatalistcodycatalist Posts: 2,617
    rmetz85 wrote: »
    rmetz85 wrote: »
    txcoastal1 wrote: »
    Bust them open, do you have a meter?

    Look a crossovers first for signs of damage. Mids and woofers next scratchy when you push gently on them. How are the tweeters? Put your ear on them when playing music.

    If any of the drivers are good from these tests move to one of the speakers to see if you can get one good speaker

    Process of elimination

    A voltage meter? Yes. Not sure what I am looking for or what to test. Visually crossovers look fine.

    Tweeters sound great. Drivers do sound a little scratchy when pushing on them with 1 finger. When with two (at 3&9) it pretty quiet until you almost max out. Both speakers are having the same issue. The right may be a little worse than the left.

    Scratchy with one yeah because your not applying even pressure so it could sound like the VC is rubbing. Try 3 or 4 points of even pressure, you don't have to push hard just move it back and forth and listen for any scratching. Do they move freely when pushing the driver or does it give you some resistance?

    I’d say pretty free. Not locked up at all.

    I’m wondering if I’m just pushing them too hard. With bass off, I can really crank it and the tweeter gets annoying loud. It’s like the driver isn’t keeping up with it.

    Does it sound like flapping at all? Sound is subjective so hard to describe, I wonder if the spider might have detached from the driver. That can cause some distortion sounds on lower frequencies. I wouldn't assume the speakers can't "keep up", if anything it would be the amp can't keep up with the levels you are trying to push.
    Just a dude doing dude-ly things

    "Temptation is the manifestation of desire which equals necessity." - Mikey081057
    " I have always had a champange taste with a beer budget" - Rick88
    "Just because the thread is getting views don't mean much .. I like a good train wreck doesn't mean i want to be in one..." - pitdogg2
    "Those that don't know, don't know that they don't know." - heiney9
    "Audiophiles are the male equivalent of cat ladies." - Audiokarma Member
  • lawdogglawdogg Posts: 364
    Occasionally the pole piece will shift only enough to cause scraping of the voice coil but not full lock. Gently put your fingers on the edges of the dust cap and push evenly inwards. If you feel rough resistance like a scraping, it's probably happened.
    <3 my 3.1TLs

    I will fix your shifted magnets for free. :)
  • mhardy6647mhardy6647 Posts: 24,519
    edited May 2018
    how "up" are you turning them? It may be(???) that they are working fine and you are asking too much of them.

    Looks like a Monitor 7A to me (although slightly different than mine, drivers are the same)... one fuse or two on the back? What value(s) is/are the fuse(s)?
    (sorry for the singular/plural mayhem!)

    9635059613_28d6560c25_b.jpgPolkmonitor7Asn4900 by Mark Hardy, on Flickr

    ik3dik2xqc56.jpeg

    EDIT: PR on the OP's looks like it's got more mass added to it than mine actually, so maybe it's more different than I thought(?).
  • mhardy6647mhardy6647 Posts: 24,519
    edited May 2018
    oh -- no hole in the dome of the OP's Peerless tweeter, either. Interesting :|

    Are both tweeters identical in appearance?

    Note that there is a hole in the center of the Peerless in the 7As here. Most, although perhaps not all, Polk speakers had this added hole (perhaps for resonance control?) in the Peerless silk dome tweeters. "Stock" Peerless KO10DT tweeters did not have the hole (Polk added it, with a soldering iron, according to posts on this forum). It may be that replacement tweeters supplied by Polk (e.g., for repairs) weren't always Holey. ;)


    nrkk0hxmg74s.png

    Full disclosure: I believe that very early Monitor 7 and 10 loudspeakers had unholey tweeters -- but the ones in this thread aren't all that early versions.

    Here's a very early Monitor 10 with unholey Peerless tweeter & uncoated paper passive radiator, e.g.

    11208619575_674f036d9b_b.jpgP1020559 by Mark Hardy, on Flickr

  • rmetz85rmetz85 Posts: 14
    mhardy6647 wrote: »
    how "up" are you turning them? It may be(???) that they are working fine and you are asking too much of them.

    Looks like a Monitor 7A to me (although slightly different than mine, drivers are the same)... one fuse or two on the back? What value(s) is/are the fuse(s)?
    (sorry for the singular/plural mayhem!)

    9635059613_28d6560c25_b.jpgPolkmonitor7Asn4900 by Mark Hardy, on Flickr

    ik3dik2xqc56.jpeg

    EDIT: PR on the OP's looks like it's got more mass added to it than mine actually, so maybe it's more different than I thought(?).

    1 fuse
  • rmetz85rmetz85 Posts: 14
    mhardy6647 wrote: »
    how "up" are you turning them? It may be(???) that they are working fine and you are asking too much of them.

    Looks like a Monitor 7A to me (although slightly different than mine, drivers are the same)... one fuse or two on the back? What value(s) is/are the fuse(s)?
    (sorry for the singular/plural mayhem!)

    9635059613_28d6560c25_b.jpgPolkmonitor7Asn4900 by Mark Hardy, on Flickr

    ik3dik2xqc56.jpeg

    EDIT: PR on the OP's looks like it's got more mass added to it than mine actually, so maybe it's more different than I thought(?).

    Also I think you’re correct that I’m asking too much out of them. If I keep the bass setting on 0 I can turn these up pretty loud without distortion.
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