EV Sentry II questions

Dabutcher
Dabutcher Posts: 2,596
edited April 2013 in Vintage Speakers
Would the screw for speaker wire that says common be for possitive wire? Also is their any problem running these when one states 8ohms and the other says 16 ohms? Thanks. D
MIT Magnum MH-750, Monster HTS 5100MKII, Sony 77" Class - A80CJ Series - 4K UHD OLED,PS4, Def Tech 15” sub,LSIM 706c, Sunfire Signature Grand 425 x 4,Parasound hca 120, LSiM 702 x 4, Oppo 103D, SDA SRS 1.2, Pioneer Elite SC63 , Pioneer Elite BDP-05 “Why did you get married if you wanted big speakers?”
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  • mhardy6647
    mhardy6647 Posts: 33,808
    edited March 2013
    Common should be the (common) ground or return (negative) connection.
    No problem per se running one 8 ohm and one 16 ohm - they will load the two amplifier channels differently. In theory, using the 8 ohm tap on one output transformer and the 16 ohm tap on the other would "equalize" the performance of the two channels - in a transformer-coupled/vacuum tube amp, of course. In practice, there may be little or no audible difference if both are on 8 ohm taps (or if the amp is output transformerless and has no adjustment provided to accommodate different load impedance.

    The Sentry monitors were pretty decent, high sensitivity loudpspeakers.

    EDIT: In case you didn't know, the data sheet for the Sentry II and IIA can be downloaded from EV at:
    http://www.electrovoice.com/downloadfile.php?i=971893 and
    http://www.electrovoice.com/downloadfile.php?i=971299 respectively

    EDIT^2 actually looking at the datasheets, it appears that the 8 and 16 ohm speakers might differ in more than just load impedance; they may not sound identical... but it's well worth finding out! :-)
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  • Dabutcher
    Dabutcher Posts: 2,596
    edited March 2013
    Thank you
    MIT Magnum MH-750, Monster HTS 5100MKII, Sony 77" Class - A80CJ Series - 4K UHD OLED,PS4, Def Tech 15” sub,LSIM 706c, Sunfire Signature Grand 425 x 4,Parasound hca 120, LSiM 702 x 4, Oppo 103D, SDA SRS 1.2, Pioneer Elite SC63 , Pioneer Elite BDP-05 “Why did you get married if you wanted big speakers?”
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  • Dabutcher
    Dabutcher Posts: 2,596
    edited March 2013
    They r in my garage rig w a pioneer SX750. I am selling them after I get my new polk Monitor 10 B 's tonight!
    MIT Magnum MH-750, Monster HTS 5100MKII, Sony 77" Class - A80CJ Series - 4K UHD OLED,PS4, Def Tech 15” sub,LSIM 706c, Sunfire Signature Grand 425 x 4,Parasound hca 120, LSiM 702 x 4, Oppo 103D, SDA SRS 1.2, Pioneer Elite SC63 , Pioneer Elite BDP-05 “Why did you get married if you wanted big speakers?”
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  • mhardy6647
    mhardy6647 Posts: 33,808
    edited March 2013
    Too bad you are in Minnesota :-)

    they'd be a nice foil for my EV Esquires...

    DSC_6442_zps49388299.jpg
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  • Dabutcher
    Dabutcher Posts: 2,596
    edited March 2013
    You are always here to answer my vintage speaker questions . Thank you sir. If my speakers hadn't been painted flat black for the ceiling of a church I think the wood used is identical to your fine looking speakers. Have a great day! D
    MIT Magnum MH-750, Monster HTS 5100MKII, Sony 77" Class - A80CJ Series - 4K UHD OLED,PS4, Def Tech 15” sub,LSIM 706c, Sunfire Signature Grand 425 x 4,Parasound hca 120, LSiM 702 x 4, Oppo 103D, SDA SRS 1.2, Pioneer Elite SC63 , Pioneer Elite BDP-05 “Why did you get married if you wanted big speakers?”
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  • Dabutcher
    Dabutcher Posts: 2,596
    edited March 2013
    Got the new 10A monitors home tonight and started to get the EV Sentry II 's for sale on CL. Took the grills off and I do not know if these are all original or generic replacement drivers. The cabinets seem original just because of built quality and exact size as spec documents. Any help would help me lot to be honest with prospective buyers? As always ,thanks. DarrylAttachment not found.Attachment not found.Attachment not found.Attachment not found.Attachment not found.Attachment not found.
    MIT Magnum MH-750, Monster HTS 5100MKII, Sony 77" Class - A80CJ Series - 4K UHD OLED,PS4, Def Tech 15” sub,LSIM 706c, Sunfire Signature Grand 425 x 4,Parasound hca 120, LSiM 702 x 4, Oppo 103D, SDA SRS 1.2, Pioneer Elite SC63 , Pioneer Elite BDP-05 “Why did you get married if you wanted big speakers?”
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  • mhardy6647
    mhardy6647 Posts: 33,808
    edited March 2013
    They are almost certainly the correct and original drivers; the horn tweeter is an EV T-35 and the woofer is (most probably) a component version of the EV SP12B twincone "fullrange" driver. I wonder if that big duct was meant to be loaded with a midrange a la the EV LS-8 twincone in the Esquire I posted a photo of earlier.

    If you get bored (and it's not too late already) you might want to pull out one of the woofers and see if it is indeed a twincone driver (i.e., with a whizzer cone) or if it is a pure-play woofer (which would probably make it an EV 12BW or 12BK woofer). I think the Sentry II was a two-way speaker and configured just as you see yours.
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  • Dabutcher
    Dabutcher Posts: 2,596
    edited March 2013
    Thank you. Maybe in the next couple of days I will check that woofer out? I know these are not on the caliber of your EV's ,but any idea of current market value? I cannot find a pair anywhere online for sale to reference? Happy Easter! Darryl
    MIT Magnum MH-750, Monster HTS 5100MKII, Sony 77" Class - A80CJ Series - 4K UHD OLED,PS4, Def Tech 15” sub,LSIM 706c, Sunfire Signature Grand 425 x 4,Parasound hca 120, LSiM 702 x 4, Oppo 103D, SDA SRS 1.2, Pioneer Elite SC63 , Pioneer Elite BDP-05 “Why did you get married if you wanted big speakers?”
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  • mhardy6647
    mhardy6647 Posts: 33,808
    edited March 2013
    The Sentry speakers were pro monitors; they are likely worth more than the Esquires. The Esquires were cheap - you've got 150 to 200 smackers worth of drivers in there, I'd opine (I am not an expert on valuation).
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  • Dabutcher
    Dabutcher Posts: 2,596
    edited April 2013
    I removed the main drivers and the fronts are identical. Does the driver or the crossover make the speaker 8 or 16 ohms? The drivers have two different part numbers. 8 ohms one is #810 4482 923 and 16 is 810 7694 and 171 for a guess? Thanks. DarrylAttachment not found.
    MIT Magnum MH-750, Monster HTS 5100MKII, Sony 77" Class - A80CJ Series - 4K UHD OLED,PS4, Def Tech 15” sub,LSIM 706c, Sunfire Signature Grand 425 x 4,Parasound hca 120, LSiM 702 x 4, Oppo 103D, SDA SRS 1.2, Pioneer Elite SC63 , Pioneer Elite BDP-05 “Why did you get married if you wanted big speakers?”
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  • mhardy6647
    mhardy6647 Posts: 33,808
    edited April 2013
    Dunno about the part numbers/mfg codes. They're both (beautiful) EV SP12B twincones; if you have a DMM, check the DC resistance (DCR) of the voicecoils; the 16 ohm one should measure noticeably higher than the 8 ohm driver. The DCR will not be identical to the nominal AC impedance. The voice coil design and construction determines the driver's impedance (along with mechanical aspects of the suspension and spider assemblies). The crossover components must take the driver's impedance into account (i.e., component values for the 16 ohm driver's crossover will differ from the 8 ohm driver's). For some simple insight into crossover component selection, see http://www.parts-express.com/resources/crossover-component-selection-guide.cfm
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  • Dabutcher
    Dabutcher Posts: 2,596
    edited April 2013
    The paper cone in picture has a small tear or hole in it. If you look closely ,you can see it in the nine o'clock position. How would you repair that? I have used Goop for shoes on other cones with good luck. These are really starting to intrigue me? Seems to be hardly no info on the Sentry II's but a boatload of info on the EV SP 12B drivers. Thanks again. Darryl
    MIT Magnum MH-750, Monster HTS 5100MKII, Sony 77" Class - A80CJ Series - 4K UHD OLED,PS4, Def Tech 15” sub,LSIM 706c, Sunfire Signature Grand 425 x 4,Parasound hca 120, LSiM 702 x 4, Oppo 103D, SDA SRS 1.2, Pioneer Elite SC63 , Pioneer Elite BDP-05 “Why did you get married if you wanted big speakers?”
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  • mhardy6647
    mhardy6647 Posts: 33,808
    edited April 2013
    Goop (like "Shoe Goo", right?), sparingly applied will work for a small puncture; you want an adhesive that is light and flexible (i.e., you want to minimally affect the speaker's electro-mechanical parameters so the glue should not add much mass nor impact the cone's structural properties too much. There are many accepted ways to repair tears and punctures. Other useful glues for speakers include Aileen's Tacky Glue (similar to Elmer's white glue but dries flexible) and GC Service Cement. Single-ply tissue paper and cigarette paper are good matrices for repairing cracks and splits.

    You should find info on speaker cone repair technics at audiokarma.org if you look around.

    The SP12 is a good sounding and very sensitive extended range speaker. I'd expect those Sentry IIs to rock and roll driven by a modest powered (even a flea powered) vacuum tube amplifier. Know anyone with a single-ended 2A3 amp or a push-pull EL84 amp? :-)
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