Damping factor

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jcaut
jcaut Posts: 1,849
edited October 2001 in Technical/Setup
Could someone please give me a little more info about this specification? I have a grasp of the basic concept, in that it indicates an amp's ability to exercise control over the speakers, but....

Are there any units associated with it? Damping will vary depending on the frequency and speaker impedance, correct? Does a rating of, say, 60 @1Khz, mean much? If a damping factor is not given, is there any way (for the average guy) to measure it? I appreciate any info.

Jason
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  • George Grand
    George Grand Posts: 12,258
    edited September 2001
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    Jason,

    The way I understand it, it's the amps ability to control the woofer more than anything else. The ability to stop it on a dime, reducing unwanted "overhang". NOT an engineer here though, just a dumb Greek.

    George Grand (of the Jersey Grand's)
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  • jcaut
    jcaut Posts: 1,849
    edited September 2001
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    Thanks, George.

    That was my thinking also, that it was most meaningful for the low frequencies. I have an older (mid 80's) Pioneer integrated amp that was given to me, rated 70wpc@8 Ohms. The manual gives a damping factor of 60 at 1Khz.

    As far as I can tell, most receivers don't give a damping factor. Since I'd like to get into seperates sometime, I wanted to learn a little more about that term.

    Power aside, I was kind of curious how this little integrated amp compares to the amplifiers in the receivers I've got: Denon 3801, Marantz 2270, Kenwood KRV8070. That old Marantz is rated 70wpc also, but it seems to pack quite a punch.
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  • George Grand
    George Grand Posts: 12,258
    edited September 2001
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    That Marantz 2270 sounds like a sweet piece. I have a 2238 that doesn't have a damn scratch on it.

    The Adcom power amps have great damping factors, which is why I always felt they would be really good passive sub drivers, or the bottom halves of bi-amp capable speaks.


    George Grand (of the Jersey Grand's)
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  • I-SIG
    I-SIG Posts: 2,238
    edited September 2001
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    Yep, I think pretty much sums things up on that. I've seen a Kenwood car sub amp rated at over 9000 with some special cable attached to the negative terminal of the speaker and ran back to the amp. I'm gonna guess that this number, although unitless, could be some kind of inverse time kinda unit. Or it could be a number "waves" it can control/process per some small unit of time. I'm just shooting things out of my **** here, but it sounds good.:D

    Wes
    Link: http://polkarmy.com/forums

    Panasonic TH-42PHD8UK 42" HDTV | Polk Audio SDA-SRS's (w/RDO's & Vampire Posts) + SVS PC+ 25-31 | AudioQuest Granite (mids) + BWA Silver (highs) | Cary Audio CAD-200 | Signal Cable Silver Resolution XLR's | Wyred 4 Sound STP/SE Pre | Signal Cable Silver Resolution XLR's | Cambridge Audio azur 840C--Wadia 170i + iPod jammed w/ lossless audio--Oppo 970 | Pure|AV PF31d
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  • jcaut
    jcaut Posts: 1,849
    edited September 2001
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    I traded a guy a Sony all-in-one system for that 2270. I felt kind of bad about it, but he's happy, and I'm happy. It isn't perfect, but it's certainly not bad, and everything works. I've even got the cherry case that it fits into, but a chunk of the veneer is gone.

    Thanks, all, for the information.
    Jason
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  • procw
    procw Posts: 5
    edited September 2001
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    Jason,

    Here is a good tech read on damping factor.

    www.loudspeakers.net/technote/dampfact.html

    Best Regards, Cliff
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  • TroyD
    TroyD Posts: 13,077
    edited September 2001
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    Courtesy of George, I have a Marantz 2215B in my garage rig hooked up to a pair of Pioneer CS-88's (also courtesy of George). I LOVE the sound of that reciever. If you are looking for a "new" case, they are on ebay pretty often.

    Troy
    I plan for the future. - F1Nut
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  • jcaut
    jcaut Posts: 1,849
    edited September 2001
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    Thanks, Cliff, for that link. It was essentially what I was looking for.
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  • George Grand
    George Grand Posts: 12,258
    edited September 2001
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    A double thanks from me on that link. I do ABOUT 10 dumb things a day. I guess that "overhang" response wasn't one of them, on that day. Hope the real ones don't sneak up and bite me in the ****.

    George Grand (of the Jersey Grand's)
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  • Larry Chanin
    Larry Chanin Posts: 601
    edited October 2001
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    Jason:

    In addition to the explanations of speaker damping you may find this explanation of amplifier damping factor helpful.

    http://www.eatel.net/~amptech/elecdisc/dampfact.htm#demo

    Damping factor does not have units.
    It is calculated by measuring the loaded and no load voltage across the amplifier and applying the following formula:

    DF = E no load/(E no load-E loaded)

    The above reference also has a web calculator that permits you to determine the effect that the speaker wire has on the overall effective damping factor.

    Larry
    Larry's Home Theater
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  • jcaut
    jcaut Posts: 1,849
    edited October 2001
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    Thanks, Larry!

    That was exactly the information I was looking for (even though it was a car audio site :D ).
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