Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.sys.mac.system > #56157

Re: Experience with Smith Micro?

From J Burns <burns4@nowhere.com>
Newsgroups comp.sys.mac.system
Subject Re: Experience with Smith Micro?
Date 2014-02-06 17:59 -0500
Organization A noiseless patient Spider
Message-ID <ld1457$tnu$1@dont-email.me> (permalink)
References (3 earlier) <gcy51p1vx8.fsf@ethel.the.log> <SalmonEgg-A74B4B.11023505022014@news80.forteinc.com> <h-ydncr4CsadXG_PnZ2dnUVZ_uKdnZ2d@giganews.com> <lcutlf$va7$1@dont-email.me> <ld0j9m$bdg$1@reader2.panix.com>

Show all headers | View raw

On 2/6/14, 1:12 PM, billy@MIX.COM wrote:
> J Burns <burns4@nowhere.com> writes:
>
>> Headphone jacks used to have a 220-ohm resistor in series.  I listened
>> to my Koss Pro4AAs for years that way.  Then I read about damping
>> factors.
>
> I don't know what you read, but if it wasn't this...
>
> http://diyspeakers.net/Articles/Richard%20Pierce%20DAMPING%20FACTOR.pdf
>
> ...I highly recommend you take a look now.

Thank you!

>
> | 6 CONCLUSIONS
> |
> | There may be audible differences that are caused by non-zero source
> | resistance. However, this analysis and any mode of measurement and
> | listening demonstrates conclusively that it is not due to the
> | changes in damping the motion of the cone at the point where it's at
> | its most uncontrolled: system resonances. We have not looked at the
> | frequency-dependent attenuative effects of the source resistance,
> | but that's not what the strident claims are about.
> |
> | Rather, the people advocating the importance of high damping factors
> | must look elsewhere for a culprit: motion control at resonance
> | simply fails utterly to explain the claimed differences.

I knew you could damp a meter needle or an electric motor by shorting 
the terminals, but I was never sophisticated enough to analyze how it 
might work with loudspeakers.  What I saw was a way to give the source a 
nearly flat response.

My phones were nominally 32 ohms.  In fact, they were about 20 ohms for 
bass notes and perhaps 150 ohms at some frequencies.  If the amplifier 
fed them 1 volt through 20 ohms, they would see 0.4 V at a resonant 
frequency (perhaps 2kHz) and 0.083 V at a nonresonant frequency (perhaps 
50Hz). That would mean a difference of about 14dB in the signal seen by 
the phones at various frequencies.

A 2-ohm source would flatten it out, to a difference of only 0.6dB in 
the voltage seen by the phones at different frequencies.  They were 
easier on the ears and I could hear more.

In series with a 10-ohm resistor, a $500 8-ohm speaker will probably 
sound pretty bad.  As the paper said, there may be no audible difference 
between two high damping factors, but a speaker doesn't sound good with 
a factor of about 1.

>
>> So I used a resistor network to feed my phones with 2 ohms.  What an
>> improvement!
>
> A piece of wire (essentially zero ohms) would have had the same effect.
> Headphone amplifiers need a load - generally about 32~75 ohms - to work
> well.  This is a common problem in my work, where someone wants to feed
> music from a phone or laptop computer into a PA system.  If a cable is
> plugged into the headphone output jack, going to a relatively high
> impedance inputs, a suitable load for the outputs needs to be provided.
> I've lost count of how many cables I've built for this...
>
> Billy Y..
>
As I recall, I might put a 20-ohm resistor in series with a 2-ohm 
resistor.  I'd connect the free end of the 2-ohm resistor to ground and 
the free end of the 20-ohm resistor to the amplifier output.  I'd run a 
wire from the resistor junction to my headphone jack.

That would give me an output impedance of about 1.8 ohm. It would also 
reduce the voltage by 91%.  That would keep me from blowing my phones if 
I set the volume too high.  It was also a way to minimize crossover 
distortion.

If the manufacturer specifies a certain percent crossover distortion 
with a 40V signal, and you turn the volume down to 0.1 V to listen with 
headphones, crossover distortion will be 400 times higher.  If I use a 
1:11 stepdown resistor network to listen at 0.1 V, I can turn up the 
volume knob, reducing crossover distortion by 91%, I guess.

Back to comp.sys.mac.system | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Experience with Smith Micro? Salmon Egg <SalmonEgg@sbcglobal.net> - 2014-02-04 21:56 -0800
  Re: Experience with Smith Micro? Doug Anderson <ethelthelogremovethis@gmail.com> - 2014-02-04 22:14 -0800
    Re: Experience with Smith Micro? Savageduck <savageduck1@{REMOVESPAM}me.com> - 2014-02-05 05:03 -0800
      Re: Experience with Smith Micro? Doug Anderson <ethelthelogremovethis@gmail.com> - 2014-02-05 06:22 -0800
        Re: Experience with Smith Micro? J Burns <burns4@nowhere.com> - 2014-02-05 12:24 -0500
          Re: Experience with Smith Micro? Michelle Steiner <michelle@michelle.org> - 2014-02-05 10:52 -0700
            Re: Experience with Smith Micro? J Burns <burns4@nowhere.com> - 2014-02-05 12:53 -0500
            Re: Experience with Smith Micro? J Burns <burns4@nowhere.com> - 2014-02-05 13:04 -0500
          Re: Experience with Smith Micro? nospam <nospam@nospam.invalid> - 2014-02-05 13:34 -0500
          Re: Experience with Smith Micro? Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-02-05 17:48 -0500
          Re: Experience with Smith Micro? Lewis <g.kreme@gmail.com.dontsendmecopies> - 2014-02-05 23:40 +0000
            Re: Experience with Smith Micro? nospam <nospam@nospam.invalid> - 2014-02-05 20:14 -0500
            Re: Experience with Smith Micro? J Burns <burns4@nowhere.com> - 2014-02-05 21:59 -0500
              Re: Experience with Smith Micro? JF Mezei <jfmezei.spamnot@vaxination.ca> - 2014-02-05 22:18 -0500
                Re: Experience with Smith Micro? J Burns <burns4@nowhere.com> - 2014-02-05 23:12 -0500
        Re: Experience with Smith Micro? Salmon Egg <SalmonEgg@sbcglobal.net> - 2014-02-05 11:02 -0800
          Re: Experience with Smith Micro? Doug Anderson <ethelthelogremovethis@gmail.com> - 2014-02-05 11:16 -0800
            Re: Experience with Smith Micro? Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-02-05 17:54 -0500
          Re: Experience with Smith Micro? nospam <nospam@nospam.invalid> - 2014-02-05 15:39 -0500
          Re: Experience with Smith Micro? Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-02-05 17:53 -0500
            Re: Experience with Smith Micro? J Burns <burns4@nowhere.com> - 2014-02-05 21:56 -0500
              Re: Experience with Smith Micro? billy@MIX.COM - 2014-02-06 18:12 +0000
                Re: Experience with Smith Micro? J Burns <burns4@nowhere.com> - 2014-02-06 17:59 -0500
                Re: Experience with Smith Micro? Salmon Egg <SalmonEgg@sbcglobal.net> - 2014-02-06 18:18 -0800
                Re: Experience with Smith Micro? billy@MIX.COM - 2014-02-07 03:09 +0000
                Re: Experience with Smith Micro? Salmon Egg <SalmonEgg@sbcglobal.net> - 2014-02-08 16:51 -0800
                Re: Experience with Smith Micro? billy@MIX.COM - 2014-02-09 03:51 +0000
                Re: soured vibrations J Burns <burns4@nowhere.com> - 2014-02-07 10:10 -0500
                Re: soured vibrations Salmon Egg <SalmonEgg@sbcglobal.net> - 2014-02-07 16:39 -0800
              Re: Experience with Smith Micro? Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-02-07 16:50 -0500
                Re: Experience with Smith Micro? J Burns <burns4@nowhere.com> - 2014-02-07 18:11 -0500
                Re: Experience with Smith Micro? Salmon Egg <SalmonEgg@sbcglobal.net> - 2014-02-09 15:49 -0800
                Re: Experience with Smith Micro? J Burns <burns4@nowhere.com> - 2014-02-09 21:01 -0500
                Re: Experience with Smith Micro? Salmon Egg <SalmonEgg@sbcglobal.net> - 2014-02-10 00:26 -0800
                Re: Experience with Smith Micro? J Burns <burns4@nowhere.com> - 2014-02-10 11:39 -0500
                Re: Experience with Smith Micro? Salmon Egg <SalmonEgg@sbcglobal.net> - 2014-02-10 16:51 -0800
                Re: Experience with Smith Micro? J Burns <burns4@nowhere.com> - 2014-02-13 05:48 -0500
                Re: Experience with Smith Micro? Salmon Egg <SalmonEgg@sbcglobal.net> - 2014-02-08 22:53 -0800
                Re: Experience with Smith Micro? Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-02-09 09:16 -0500
            Re: Experience with Smith Micro? Salmon Egg <SalmonEgg@sbcglobal.net> - 2014-02-05 19:16 -0800
              Re: Experience with Smith Micro? JF Mezei <jfmezei.spamnot@vaxination.ca> - 2014-02-05 23:09 -0500
                Re: Experience with Smith Micro? J Burns <burns4@nowhere.com> - 2014-02-06 00:27 -0500
                Re: Experience with Smith Micro? nospam <nospam@nospam.invalid> - 2014-02-06 01:20 -0500
                Re: Experience with Smith Micro? Salmon Egg <SalmonEgg@sbcglobal.net> - 2014-02-08 16:42 -0800
                Re: Experience with Smith Micro? Jim Gibson <jimsgibson@gmail.com> - 2014-02-06 12:38 -0800
              Re: Experience with Smith Micro? Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-02-07 16:52 -0500
    Re: Experience with Smith Micro? Salmon Egg <SalmonEgg@sbcglobal.net> - 2014-02-05 06:20 -0800
      Re: Experience with Smith Micro? nospam <nospam@nospam.invalid> - 2014-02-05 12:13 -0500
        Re: Experience with Smith Micro? Michelle Steiner <michelle@michelle.org> - 2014-02-05 10:47 -0700
          Re: Experience with Smith Micro? Salmon Egg <SalmonEgg@sbcglobal.net> - 2014-02-05 11:36 -0800
            Re: Experience with Smith Micro? nospam <nospam@nospam.invalid> - 2014-02-05 15:39 -0500
            Re: Experience with Smith Micro? Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-02-05 18:10 -0500
              Re: Experience with Smith Micro? J Burns <burns4@nowhere.com> - 2014-02-05 22:14 -0500
                Re: Experience with Smith Micro? Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-02-07 16:45 -0500
                Re: Experience with Smith Micro? J Burns <burns4@nowhere.com> - 2014-02-07 23:38 -0500
                Re: Experience with Smith Micro? Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-02-08 09:34 -0500
                Re: Experience with Smith Micro? Salmon Egg <SalmonEgg@sbcglobal.net> - 2014-02-09 16:15 -0800
                Re: Experience with Smith Micro? J Burns <burns4@nowhere.com> - 2014-02-09 21:52 -0500
        Re: Experience with Smith Micro? Salmon Egg <SalmonEgg@sbcglobal.net> - 2014-02-05 11:22 -0800
          Re: Experience with Smith Micro? nospam <nospam@nospam.invalid> - 2014-02-05 15:39 -0500
            Re: Experience with Smith Micro? Salmon Egg <SalmonEgg@sbcglobal.net> - 2014-02-05 18:36 -0800
              Re: Experience with Smith Micro? nospam <nospam@nospam.invalid> - 2014-02-05 21:43 -0500
        Re: Experience with Smith Micro? Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-02-05 18:04 -0500
          Re: Experience with Smith Micro? nospam <nospam@nospam.invalid> - 2014-02-05 18:19 -0500
            Re: Experience with Smith Micro? Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-02-05 21:03 -0500
              Re: Experience with Smith Micro? nospam <nospam@nospam.invalid> - 2014-02-05 21:40 -0500
                Re: Experience with Smith Micro? Savageduck <savageduck1@{REMOVESPAM}me.com> - 2014-02-05 23:21 -0800
                Re: Experience with Smith Micro? android <here@there.was> - 2014-02-06 08:47 +0100
                Re: Experience with Smith Micro? Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-02-07 16:55 -0500
                Re: Experience with Smith Micro? nospam <nospam@nospam.invalid> - 2014-02-07 18:43 -0500
                Re: Experience with Smith Micro? Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-02-07 18:48 -0500
                Re: Experience with Smith Micro? Jolly Roger <jollyroger@pobox.com> - 2014-02-08 02:09 +0000
                Re: Experience with Smith Micro? nospam <nospam@nospam.invalid> - 2014-02-07 22:23 -0500
                Re: Experience with Smith Micro? nospam <nospam@nospam.invalid> - 2014-02-07 22:23 -0500
                Re: Experience with Smith Micro? Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-02-08 09:32 -0500
                Re: Experience with Smith Micro? nospam <nospam@nospam.invalid> - 2014-02-08 12:54 -0500
                Re: Experience with Smith Micro? Salmon Egg <SalmonEgg@sbcglobal.net> - 2014-02-09 16:32 -0800
                Re: Experience with Smith Micro? JF Mezei <jfmezei.spamnot@vaxination.ca> - 2014-02-09 22:38 -0500
                Re: Experience with Smith Micro? JF Mezei <jfmezei.spamnot@vaxination.ca> - 2014-02-07 19:48 -0500
      Re: Experience with Smith Micro? Michelle Steiner <michelle@michelle.org> - 2014-02-05 10:25 -0700
        Re: Experience with Smith Micro? J Burns <burns4@nowhere.com> - 2014-02-05 12:58 -0500
          Re: Experience with Smith Micro? Salmon Egg <SalmonEgg@sbcglobal.net> - 2014-02-05 11:48 -0800
        Re: Experience with Smith Micro? nospam <nospam@nospam.invalid> - 2014-02-05 13:34 -0500
          Re: Experience with Smith Micro? Michelle Steiner <michelle@michelle.org> - 2014-02-05 12:13 -0700
            Re: Experience with Smith Micro? Doug Anderson <ethelthelogremovethis@gmail.com> - 2014-02-05 11:18 -0800
            Re: Experience with Smith Micro? nospam <nospam@nospam.invalid> - 2014-02-05 15:39 -0500
              Re: Experience with Smith Micro? "John Varela" <newlamps@verizon.net> - 2014-02-05 22:34 +0000
                Re: Experience with Smith Micro? Jolly Roger <jollyroger@pobox.com> - 2014-02-05 23:10 +0000
                Re: Experience with Smith Micro? nospam <nospam@nospam.invalid> - 2014-02-05 18:19 -0500
                Re: Experience with Smith Micro? "John Varela" <newlamps@verizon.net> - 2014-02-06 23:56 +0000
    Re: Experience with Smith Micro? Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-02-05 17:45 -0500
  Re: Experience with Smith Micro? Jim Jaeger <jimjaeger@example.com> - 2014-02-04 23:04 -0800
    Re: Experience with Smith Micro? Salmon Egg <SalmonEgg@sbcglobal.net> - 2014-02-05 06:28 -0800
      Re: Experience with Smith Micro? Jim Jaeger <jimjaeger@example.com> - 2014-02-05 11:04 -0800
    Re: Experience with Smith Micro? billy@MIX.COM - 2014-02-05 20:47 +0000
  Re: Experience with Smith Micro? Alan Ralph <alan.ralph@gmail.com> - 2014-02-05 18:22 +0000
    Re: Experience with Smith Micro? Salmon Egg <SalmonEgg@sbcglobal.net> - 2014-02-08 16:09 -0800
      Re: Experience with Smith Micro? nospam <nospam@nospam.invalid> - 2014-02-08 20:01 -0500
        Re: Experience with Smith Micro? Salmon Egg <SalmonEgg@sbcglobal.net> - 2014-02-09 16:46 -0800
      Re: Experience with Smith Micro? billy@MIX.COM - 2014-02-09 01:26 +0000
  Re: Experience with Smith Micro? me@home.spamsucks.ca (Kiraly) - 2014-02-05 23:49 +0000
  Re: Experience Smith Micro Progress maybe Salmon Egg <SalmonEgg@sbcglobal.net> - 2014-02-11 15:56 -0800
    Re: Experience Smith Micro Progress maybe Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-02-11 19:13 -0500

csiph-web