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    Impedance Levels

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    bluemeanies

    Posts : 120
    Join date : 2015-02-09
    Age : 66
    Location : Folsom Pa.

    Impedance Levels

    Post by bluemeanies on Fri Aug 28, 2015 7:27 am

    Let's mix this up a little all viewpoints noted.
    I have the upgrade urge from my B&W804S speakers and graduating to the 803d/804d speakers whose impedance levels are rated at a nominal 8ohms...key word nominal!
    In researching both speakers I read though not officially but from an owner of the 803d's that when performing the the 803d's impedance level drops to 4ohms and possibly below to 3.2.  
    In all my years I have never heard this concept when buying speakers and have never read about this in any manual or forum.  I would think that something so important to the safety of ones amplifier tube/SS it would be an issue to be dealt with as a marketing caveat.
    Is this a fact? or someone's opinion since he did not mention how he came about this conclusion.
    I am driving my 804S with the m125's using the 8ohm tap and they both work flawlessly, however am I putting a heavy load on my 125's?...burning the tubes before there time?
    I will be contacting B&W here in the America's to get technical support on this issue but I respect the views on this forum from many knowledgable and frankly smart people.

    Thank you,
    F

    Elrick

    Posts : 71
    Join date : 2012-09-02
    Location : Bellingham WA

    Re: Impedance Levels

    Post by Elrick on Fri Aug 28, 2015 8:27 am

    Take a look at this topic: http://dynacotubeaudio.forumotion.com/t2754-hooking-up-6ohm-speakers-into-an-m-125

    I wouldn't worry about it, most people just want stuff to work and sound good and don't want to get lost in the electrical engineering weeds so manufactures probably choose to keep it simple and not potential customers by including too much ancillary information in their manuals.

    I run an older pair of B&W's, CDM7NT's. I'm curious on your impressions of your B&W's and your reasons for upgrading. I caught that bug a year ago but never upgraded. Couldn't justify the change.

    Kentley

    Posts : 295
    Join date : 2015-03-06
    Age : 64
    Location : Worcester, MA

    Re: Impedance Levels

    Post by Kentley on Fri Aug 28, 2015 4:16 pm

    N.B. Most B&W aficianados agree that the best speakers Bowers and Wilkins have made are the earlier Matrix series before the Nautilis. The Diamond series apparently suffers from the "more glitz, less substance" syndrome. Were I you, I would seek 803s from that Golden Era, which would also cost substantially less. Let's talk privately.
    As far as your impedance dilemma is concerned, I still stand by my personal observation that my 803s sound better on the 4 ohm taps. Unless you are blasting heavy metal, I believe that what Dr. Latino says is true - you are not damaging anything on either choice of tap. Part of this has to do with the durability and simplicity of the VTA circuits. The other consideration, as has been made clear by several good posters, is that "nominal impedance" is a vague average. Any audible differences would be dependent on your ears. If you concentrate {subconsciously or consciously} on a particular frequency spectrum, you will want the impedance match to be optimal in that range. It involves a certain amount of compromise - as does everything in music reproduction.


    Last edited by Kentley on Fri Aug 28, 2015 4:17 pm; edited 1 time in total (Reason for editing : typo)

    bluemeanies

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    Re: Impedance Levels

    Post by bluemeanies on Sat Aug 29, 2015 10:41 am

    Elrick wrote:Take a look at this topic: http://dynacotubeaudio.forumotion.com/t2754-hooking-up-6ohm-speakers-into-an-m-125

    I wouldn't worry about it, most people just want stuff to work and sound good and don't want to get lost in the electrical engineering weeds so manufactures probably choose to keep it simple and not potential customers by including too much ancillary information in their manuals.

    I run an older pair of B&W's, CDM7NT's. I'm curious on your impressions of your B&W's and your reasons for upgrading. I caught that bug a year ago but never upgraded. Couldn't justify the change.  

    Elrick..thank you.
    I am fortunate in that I have a dedicated room that "with a little help from my friends" I completed in 2001...a year and a half in the making.
    I have owned my 804's since 2007 and have been happy with them. At the time when the diamonds came out in both the 803/804 I frankly could not afford them so ultimalty they were put on the back burner.
    The 804's serve me well in both formats.
    I am new to tubes thanks to a friend I had met on the Emotiva Forum who introduced me to Bob Latino's amplifiers. My current 2channel system reluctantly I can NOT lay claim to the thought process that was put into it. At best I had little genuine thought about what products I wanted in a 2channel stereo system. I was listening to my music thru my Outlaw990/7700 combo which was adequate but way below my expectations. The Outlaw work flawlessly in my HT setup and continues to give me enjoyment.
    I was disappointed in my 2channel to the point I purchased 2XPA1's second generation after reading how much better to have addition HEADROOM with these amplifiers.
    Again I was disappointed. Thru the Emo forum I met Bill Gratrix. Bill graciously invited me to his home to give a listen two his system having the m125's.
    In short I was in awe of how dynamic and transparent his system sounded to me. Not loud, no need for EXTRA headroom Bill's system was as if the artist presence was in the room.
    I was convinced that tubes were the answer. The warmth that tubes give to well record music is a big difference than SS.
    In short I sold some of my equipment and invested in Bill's ideas who from my initial meeting trusted in his experience and i liked what he was telling me in how to attain a quality 2channel stereo system.
    The 804's sound great and at this point I am not sure about either the 803d/804d...BUT I am still considering a change for more transparency in a speaker. I feel the 804d has it, the 803d has it both at different levels. I am going to a demonstration this week to listen to both speakers.
    I don't think you would disagree with the performance level of the diamond series assuming you have heard them.
    Even with the demo pricing the B&W's are not cheap but many would consider them a bargain. I have read that for resale value theB&W's are one of the top three speakers on the market.now here's what I find interesting. Yesterday I was at an audio show in Rockville Md and I had a chance to listen to Salk speakers.
    Jim Salk had a prototype speaker there in white, with a ribbon tweeter, mid-range and two woofers. The speaker is not on his web site or is he advertising.
    I asked him if I could hear them and I can tell you that new Salk was in the mid-range clear as a bell and one of the most transparent speakers I have heard.
    My friend who had in the last year purchased a pair of Focal speakers for $5000.00 was blown away and wished he heard the Salk before buying his Focal.
    Price of these beauties..$3000.00 with any finish.
    So now I am considering the Salk with a gauranteed refund if the speakers do not work in my system or consideration of another Salk model.

    This is my reasoning, perhaps insane but it's an honest account of my travels on this road and where I am in the journey.

    sKiZo

    Posts : 1285
    Join date : 2013-04-01
    Location : Michigan USA

    Re: Impedance Levels

    Post by sKiZo on Sat Aug 29, 2015 11:24 am

    Your basic starter system ...


    GP49

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    Join date : 2009-04-30
    Location : East of the sun and west of the moon

    Re: Impedance Levels

    Post by GP49 on Sat Aug 29, 2015 12:13 pm

    Before accepting any "user" at his word about the impedance of his loudspeakers, I would need to know how he measured it. Almost certainly he used a multimeter, which is guaranteed to be wrong.

    tubes4hifi
    Admin

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    Join date : 2008-11-30

    Re: Impedance Levels

    Post by tubes4hifi on Sat Aug 29, 2015 6:33 pm

    BlueMeanies - speaker impedance is never a static measurement, here's a link to a graph of the B&W804, which is very very typical of a speaker system,
    in fact it's near identical to a pair of speakers I own, totally different brand.   Impedance around 100Hz and 20Hz is about 3 ohms,
    peak impedance looks to be near 30 ohms around 2800Hz.  
    This image is from a test Stereophile did a few years ago.
    Yeah, so you wonder how they come up with 8 ohm nominal (which is supposely the "average").
    So you can try them on either the 4 ohm or 8 ohm tap, my guess the 8 ohm tap will work perfectly fine.

    SkiZo - yeah, nice starter system, just need to replace the amps with M125s and add some bass absorbers in the back corners.

    bluemeanies

    Posts : 120
    Join date : 2015-02-09
    Age : 66
    Location : Folsom Pa.

    Re: Impedance Levels

    Post by bluemeanies on Sun Aug 30, 2015 10:54 am

    tubes4hifi wrote:BlueMeanies - speaker impedance is never a static measurement, here's a link to a graph of the B&W804, which is very very typical of a speaker system,
    in fact it's near identical to a pair of speakers I own, totally different brand.   Impedance around 100Hz and 20Hz is about 3 ohms,
    peak impedance looks to be near 30 ohms around 2800Hz.  
    This image is from a test Stereophile did a few years ago.
    Yeah, so you wonder how they come up with 8 ohm nominal (which is supposely the "average").
    So you can try them on either the 4 ohm or 8 ohm tap, my guess the 8 ohm tap will work perfectly fine.

    SkiZo - yeah, nice starter system, just need to replace the amps with M125s and add some bass absorbers in the back corners.

    Thank you...love that BASIC starter system!
    SkiZo....

    bluemeanies

    Posts : 120
    Join date : 2015-02-09
    Age : 66
    Location : Folsom Pa.

    Re: Impedance Levels

    Post by bluemeanies on Tue Sep 01, 2015 7:34 am

    Elrick wrote:Take a look at this topic: http://dynacotubeaudio.forumotion.com/t2754-hooking-up-6ohm-speakers-into-an-m-125

    I wouldn't worry about it, most people just want stuff to work and sound good and don't want to get lost in the electrical engineering weeds so manufactures probably choose to keep it simple and not potential customers by including too much ancillary information in their manuals.

    I run an older pair of B&W's, CDM7NT's. I'm curious on your impressions of your B&W's and your reasons for upgrading. I caught that bug a year ago but never upgraded. Couldn't justify the change.  


    Elrick...thank you for the information.
    I am a bit more relaxed now b/c of your article and everyone's help.

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