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Groups > comp.sys.mac.system > #55935 > unrolled thread
| Started by | Salmon Egg <SalmonEgg@sbcglobal.net> |
|---|---|
| First post | 2014-02-04 21:56 -0800 |
| Last post | 2014-02-11 19:13 -0500 |
| Articles | 20 on this page of 103 — 17 participants |
Back to article view | Back to comp.sys.mac.system
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
Page 2 of 6 — ← Prev page 1 [2] 3 4 5 6 Next page →
| From | J Burns <burns4@nowhere.com> |
|---|---|
| Date | 2014-02-05 21:56 -0500 |
| Message-ID | <lcutlf$va7$1@dont-email.me> |
| In reply to | #56049 |
On 2/5/14, 5:53 PM, Alan Browne wrote: > On 2014.02.05, 14:02 , Salmon Egg wrote: >> In article <gcy51p1vx8.fsf@ethel.the.log>, >> Doug Anderson <ethelthelogremovethis@gmail.com> wrote: >> >>>> So it does nothing? >>> >>> For audiophiles with really refined ears, the difference is like night >>> and day. >> >> It does something only with their imaginations. What does monster cable >> actually do? Can you compare the transfer function of monster cable to >> that of cheap speaker wire for a q0 or 20 foot run? What does it do for >> the shape of a square wave at 1 or 5 kHz? How big are the effects of >> using small speaker wires compared to room resonances in a typical audio >> "listening" room? We are not talking about an anechoic chamber that >> would have been in the former Bell Labs. > > > There are simple rules (formulae) for speaker impedance, wire run length > and power (for a given wire type such as copper) that put a lower bound > on the size of the wire. If the wire is that thickness or thicker, > you're done. To be conservative, if the calculation indicates 14 gauge, > for example, then one could use 12 gauge for additional margin. > > Wire coat hangars are just as good as 10 or 12 gauge wire, for example. > It looks to me as if a wire coat hanger has resistance about equal to 20 gauge copper. Maybe you mean a hanger for wire coats. My wire coat is pretty heavy (and not very warm), so I guess the hanger would be a bigger gauge than an ordinary coat hanger. 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. A speaker resonates at certain frequencies. It will resonate less if fed by a lower impedance relative to the speaker's characteristic impedance. So I used a resistor network to feed my phones with 2 ohms. What an improvement! I don't know about skin effect and high frequencies, but 14 gauge copper might offer a significantly better damping factor than 28 gauge.
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| From | billy@MIX.COM |
|---|---|
| Date | 2014-02-06 18:12 +0000 |
| Message-ID | <ld0j9m$bdg$1@reader2.panix.com> |
| In reply to | #56105 |
J Burns <burns4@nowhere.com> writes:
> Headphone jacks used to have a 220-ohm resistor in series. I listened
> to my Koss Pro4AAs for years that way. Then I read about damping
> factors.
I don't know what you read, but if it wasn't this...
http://diyspeakers.net/Articles/Richard%20Pierce%20DAMPING%20FACTOR.pdf
...I highly recommend you take a look now.
| 6 CONCLUSIONS
|
| There may be audible differences that are caused by non-zero source
| resistance. However, this analysis and any mode of measurement and
| listening demonstrates conclusively that it is not due to the
| changes in damping the motion of the cone at the point where it's at
| its most uncontrolled: system resonances. We have not looked at the
| frequency-dependent attenuative effects of the source resistance,
| but that's not what the strident claims are about.
|
| Rather, the people advocating the importance of high damping factors
| must look elsewhere for a culprit: motion control at resonance
| simply fails utterly to explain the claimed differences.
> So I used a resistor network to feed my phones with 2 ohms. What an
> improvement!
A piece of wire (essentially zero ohms) would have had the same effect.
Headphone amplifiers need a load - generally about 32~75 ohms - to work
well. This is a common problem in my work, where someone wants to feed
music from a phone or laptop computer into a PA system. If a cable is
plugged into the headphone output jack, going to a relatively high
impedance inputs, a suitable load for the outputs needs to be provided.
I've lost count of how many cables I've built for this...
Billy Y..
--
sub #'9+1 ,r0 ; convert ascii byte
add #9.+1 ,r0 ; to an integer
bcc 20$ ; not a number
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| From | J Burns <burns4@nowhere.com> |
|---|---|
| Date | 2014-02-06 17:59 -0500 |
| Message-ID | <ld1457$tnu$1@dont-email.me> |
| In reply to | #56142 |
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 $500 8-ohm speaker will probably sound pretty bad. As the paper said, there may be no audible difference between two high damping factors, but a speaker doesn't sound good with a factor of about 1. > >> So I used a resistor network to feed my phones with 2 ohms. What an >> improvement! > > A piece of wire (essentially zero ohms) would have had the same effect. > Headphone amplifiers need a load - generally about 32~75 ohms - to work > well. This is a common problem in my work, where someone wants to feed > music from a phone or laptop computer into a PA system. If a cable is > plugged into the headphone output jack, going to a relatively high > impedance inputs, a suitable load for the outputs needs to be provided. > I've lost count of how many cables I've built for this... > > Billy Y.. > As I recall, I might put a 20-ohm resistor in series with a 2-ohm resistor. I'd connect the free end of the 2-ohm resistor to ground and the free end of the 20-ohm resistor to the amplifier output. I'd run a wire from the resistor junction to my headphone jack. That would give me an output impedance of about 1.8 ohm. It would also reduce the voltage by 91%. That would keep me from blowing my phones if I set the volume too high. It was also a way to minimize crossover distortion. If the manufacturer specifies a certain percent crossover distortion with a 40V signal, and you turn the volume down to 0.1 V to listen with headphones, crossover distortion will be 400 times higher. If I use a 1:11 stepdown resistor network to listen at 0.1 V, I can turn up the volume knob, reducing crossover distortion by 91%, I guess.
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| From | Salmon Egg <SalmonEgg@sbcglobal.net> |
|---|---|
| Date | 2014-02-06 18:18 -0800 |
| Message-ID | <SalmonEgg-8E8BFF.18184306022014@news80.forteinc.com> |
| In reply to | #56142 |
In article <ld0j9m$bdg$1@reader2.panix.com>, billy@MIX.COM wrote: > A piece of wire (essentially zero ohms) would have had the same effect. > Headphone amplifiers need a load - generally about 32~75 ohms - to work > well. This is a common problem in my work, where someone wants to feed > music from a phone or laptop computer into a PA system. If a cable is > plugged into the headphone output jack, going to a relatively high > impedance inputs, a suitable load for the outputs needs to be provided. > I've lost count of how many cables I've built for this... This is not the forum for HiFi components. I just mention, that a voice coil is a MOTOR. If you jolt a speaker into vibrating, it can do so. If driven from a low impedance soured vibrations will be damped. Various mechanical impedances will show up as electrical impedance. Discuss details elsewhere. -- Sam Conservatives are against Darwinism but for natural selection. Liberals are for Darwinism but totally against any selection.
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| From | billy@MIX.COM |
|---|---|
| Date | 2014-02-07 03:09 +0000 |
| Message-ID | <ld1ipj$q3s$1@reader2.panix.com> |
| In reply to | #56166 |
Salmon Egg <SalmonEgg@sbcglobal.net> writes:
> This is not the forum for HiFi components.
> [...] Discuss details elsewhere.
You might consider practicing what you preach.
As for me, after 30+ years of experience with
discussions like this one, the one thing I do
know is even trying to move it elsewhere is a
complete waste of time.
Billy Y..
--
sub #'9+1 ,r0 ; convert ascii byte
add #9.+1 ,r0 ; to an integer
bcc 20$ ; not a number
[toc] | [prev] | [next] | [standalone]
| From | Salmon Egg <SalmonEgg@sbcglobal.net> |
|---|---|
| Date | 2014-02-08 16:51 -0800 |
| Message-ID | <SalmonEgg-9A054E.16512308022014@news80.forteinc.com> |
| In reply to | #56167 |
In article <ld1ipj$q3s$1@reader2.panix.com>, billy@MIX.COM wrote: > Salmon Egg <SalmonEgg@sbcglobal.net> writes: > > > This is not the forum for HiFi components. > > [...] Discuss details elsewhere. > > You might consider practicing what you preach. > > As for me, after 30+ years of experience with > discussions like this one, the one thing I do > know is even trying to move it elsewhere is a > complete waste of time. > > Billy Y.. OK. I am actually interested in the subject. It is difficult for me to resist commenting here when I read it here. Let me propose moving this to alt.engineering.electrical. -- Sam Conservatives are against Darwinism but for natural selection. Liberals are for Darwinism but totally against any selection.
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| From | billy@MIX.COM |
|---|---|
| Date | 2014-02-09 03:51 +0000 |
| Message-ID | <ld6tvs$95s$4@reader2.panix.com> |
| In reply to | #56261 |
Salmon Egg <SalmonEgg@sbcglobal.net> writes, quoting me:
> > As for me, after 30+ years of experience with
> > discussions like this one, the one thing I do
> > know is even trying to move it elsewhere is a
> > complete waste of time.
> OK. I am actually interested in the subject. It is difficult for me to
> resist commenting here when I read it here.
>
> Let me propose moving this to alt.engineering.electrical.
rec.audio.pro seems like a better choice, even though most of
the smart folks (including Dick Pierce, one of its founders)
have long ago given up on it (due to the same sort of nonsense
that riddles this very thread). I hardly ever peek at it myself
any more. But, there are a few well educated, experienced, very
knowledgeable people still there.
Billy Y..
--
sub #'9+1 ,r0 ; convert ascii byte
add #9.+1 ,r0 ; to an integer
bcc 20$ ; not a number
[toc] | [prev] | [next] | [standalone]
| From | J Burns <burns4@nowhere.com> |
|---|---|
| Date | 2014-02-07 10:10 -0500 |
| Subject | Re: soured vibrations |
| Message-ID | <ld2t0k$lba$1@dont-email.me> |
| In reply to | #56166 |
On 2/6/14, 9:18 PM, Salmon Egg wrote: > In article <ld0j9m$bdg$1@reader2.panix.com>, billy@MIX.COM wrote: > >> A piece of wire (essentially zero ohms) would have had the same effect. >> Headphone amplifiers need a load - generally about 32~75 ohms - to work >> well. This is a common problem in my work, where someone wants to feed >> music from a phone or laptop computer into a PA system. If a cable is >> plugged into the headphone output jack, going to a relatively high >> impedance inputs, a suitable load for the outputs needs to be provided. >> I've lost count of how many cables I've built for this... > > This is not the forum for HiFi components. I just mention, that a voice > coil is a MOTOR. If you jolt a speaker into vibrating, it can do so. If > driven from a low impedance soured vibrations will be damped. Various > mechanical impedances will show up as electrical impedance. Discuss > details elsewhere. > I want to hear more about using your speakers for motors, but I agree with you that it would be inappropriate in a thread where everybody else is talking about listening to them. I've created a subthread for you.
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| From | Salmon Egg <SalmonEgg@sbcglobal.net> |
|---|---|
| Date | 2014-02-07 16:39 -0800 |
| Subject | Re: soured vibrations |
| Message-ID | <SalmonEgg-E366F7.16391107022014@news80.forteinc.com> |
| In reply to | #56172 |
In article <ld2t0k$lba$1@dont-email.me>, J Burns <burns4@nowhere.com> wrote: > On 2/6/14, 9:18 PM, Salmon Egg wrote: > > In article <ld0j9m$bdg$1@reader2.panix.com>, billy@MIX.COM wrote: > > > >> 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... > > > > This is not the forum for HiFi components. I just mention, that a voice > > coil is a MOTOR. If you jolt a speaker into vibrating, it can do so. If > > driven from a low impedance soured vibrations will be damped. Various > > mechanical impedances will show up as electrical impedance. Discuss > > details elsewhere. > > > I want to hear more about using your speakers for motors, but I agree > with you that it would be inappropriate in a thread where everybody else > is talking about listening to them. I've created a subthread for you. There are articles on equivalent circuits for loudspeakers. I believe one is on wikipedia, but Google will lead you to others as well. As for the motor aspect, the voice coil moves until the back emf equal the applied voltage, just as in a motor. More about is elsewhere. Let us know which newsgroup contains a continuing discussion on the subject. -- Sam Conservatives are against Darwinism but for natural selection. Liberals are for Darwinism but totally against any selection.
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| From | Alan Browne <alan.browne@FreelunchVideotron.ca> |
|---|---|
| Date | 2014-02-07 16:50 -0500 |
| Message-ID | <k-2dnfBzu9elyGjPnZ2dnUVZ8jadnZ2d@giganews.com> |
| In reply to | #56105 |
On 2014.02.05, 21:56 , J Burns wrote:
> On 2/5/14, 5:53 PM, Alan Browne wrote:
>> On 2014.02.05, 14:02 , Salmon Egg wrote:
>>> In article <gcy51p1vx8.fsf@ethel.the.log>,
>>> Doug Anderson <ethelthelogremovethis@gmail.com> wrote:
>>>
>>>>> So it does nothing?
>>>>
>>>> For audiophiles with really refined ears, the difference is like night
>>>> and day.
>>>
>>> It does something only with their imaginations. What does monster cable
>>> actually do? Can you compare the transfer function of monster cable to
>>> that of cheap speaker wire for a q0 or 20 foot run? What does it do for
>>> the shape of a square wave at 1 or 5 kHz? How big are the effects of
>>> using small speaker wires compared to room resonances in a typical audio
>>> "listening" room? We are not talking about an anechoic chamber that
>>> would have been in the former Bell Labs.
>>
>>
>> There are simple rules (formulae) for speaker impedance, wire run length
>> and power (for a given wire type such as copper) that put a lower bound
>> on the size of the wire. If the wire is that thickness or thicker,
>> you're done. To be conservative, if the calculation indicates 14 gauge,
>> for example, then one could use 12 gauge for additional margin.
>>
>> Wire coat hangars are just as good as 10 or 12 gauge wire, for example.
>>
> It looks to me as if a wire coat hanger has resistance about equal to 20
> gauge copper. Maybe you mean a hanger for wire coats. My wire coat is
Depending on the laundry service I get very thin ones from one laundry
and pretty thick ones from the other so there is no standard wire hangar
resistance. Of course the length of the run is just as important. In
the example of the audiophile test I surmise the run was quite short
(one hanger per conductor - 4 in all).
> 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. A speaker resonates at certain frequencies. It will resonate
> less if fed by a lower impedance relative to the speaker's
> characteristic impedance.
One should match the output to the input. I seem to recall an amp that
had two different headphone outputs depending on the headphone impedance.
>
> So I used a resistor network to feed my phones with 2 ohms. What an
> improvement! I don't know about skin effect and high frequencies, but
> 14 gauge copper might offer a significantly better damping factor than
> 28 gauge.
A lower gauge (less resistance) should offer less damping factor. In
effect the cabling should be such that as far as the speaker is
concerned it is connected by a very, very short cable.
The skin effect on frequency at these low frequencies (audio) for an
adequately thick cable are inaudible.
The other scam these days is "oxygen free copper audio loudspeaker
wire". This magic stuff (at a much higher cost) has 1% less R than
ordinary copper cable. Not audible at all - but the suckers are always
there...
Then there are "cable supports" and other voodoo that gullible people
with more money than brains fork over.
--
Those who have reduced our privacy, whether they are state
or commercial actors, prefer that we do not reduce theirs.
- Jaron Lanier, Scientific American, 2013.11.
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| From | J Burns <burns4@nowhere.com> |
|---|---|
| Date | 2014-02-07 18:11 -0500 |
| Message-ID | <ld3p6g$3t1$1@dont-email.me> |
| In reply to | #56189 |
On 2/7/14, 4:50 PM, Alan Browne wrote: > On 2014.02.05, 21:56 , J Burns wrote: >> 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. A speaker resonates at certain frequencies. It will resonate >> less if fed by a lower impedance relative to the speaker's >> characteristic impedance. > > One should match the output to the input. I seem to recall an amp that > had two different headphone outputs depending on the headphone impedance. > If you need to transfer the most power, matching impedance is important. If the output circuit has reactive components, matching impedance is important. The amplifier didn't have any capacitors or inductors in the output. Wanting only a few milliwatts from a 50-watt amp, I wasn't worried about power transfer. Initially, I added 39-ohm resistors at the headphone jack to bring the output impedance down to 33 ohms, a close match to the nominal 32 ohms of my phones. It was an improvement, but the 1.8-ohm adapter I made with 10-watt resistors sounded better.
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| From | Salmon Egg <SalmonEgg@sbcglobal.net> |
|---|---|
| Date | 2014-02-09 15:49 -0800 |
| Message-ID | <SalmonEgg-A260CA.15490609022014@news80.forteinc.com> |
| In reply to | #56195 |
In article <ld3p6g$3t1$1@dont-email.me>, J Burns <burns4@nowhere.com> wrote: > If you need to transfer the most power, matching impedance is important. > If the output circuit has reactive components, matching impedance is > important. > > The amplifier didn't have any capacitors or inductors in the output. > Wanting only a few milliwatts from a 50-watt amp, I wasn't worried about > power transfer. First, move responses to alt.engineering.electrical. Most, should I say all, have large negative feedback. Gain these days is cheap. Negative feedback removes distortion arising from nonlinearity of the power components in the amplifier. In particular, voltage feedback makes amplifiers look like low impedance sources. Speaker wire resistance adds to the impedance of the effective source driving the speaker. Even so, unless there are long runs of relatively small speaker wire, that increase in source impedance is small. Monster cable is an expensive and unnecessary way of minimizing the effective source impedance. Negative current feedback increases source impedance to where the amplifier becomes a constant current source. Any natural vibrations of the speaker will not be damped under those circumstances. -- Sam Conservatives are against Darwinism but for natural selection. Liberals are for Darwinism but totally against any selection.
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| From | J Burns <burns4@nowhere.com> |
|---|---|
| Date | 2014-02-09 21:01 -0500 |
| Message-ID | <ld9bu9$lo$1@dont-email.me> |
| In reply to | #56313 |
On 2/9/14, 6:49 PM, Salmon Egg wrote: > In article <ld3p6g$3t1$1@dont-email.me>, J Burns <burns4@nowhere.com> > wrote: > >> If you need to transfer the most power, matching impedance is important. >> If the output circuit has reactive components, matching impedance is >> important. >> >> The amplifier didn't have any capacitors or inductors in the output. >> Wanting only a few milliwatts from a 50-watt amp, I wasn't worried about >> power transfer. > > First, move responses to alt.engineering.electrical. > > Most, should I say all, have large negative feedback. Gain these days is > cheap. Negative feedback removes distortion arising from nonlinearity of > the power components in the amplifier. > > In particular, voltage feedback makes amplifiers look like low impedance > sources. Speaker wire resistance adds to the impedance of the effective > source driving the speaker. Even so, unless there are long runs of > relatively small speaker wire, that increase in source impedance is > small. Monster cable is an expensive and unnecessary way of minimizing > the effective source impedance. > > Negative current feedback increases source impedance to where the > amplifier becomes a constant current source. Any natural vibrations of > the speaker will not be damped under those circumstances. > If the impedance of my phones varied from 20 to 170 ohms depending on frequency, I could say a 220-ohm resistor in series had the effect of negative current feedback. With my resistor network, the amplifier saw more than 20 ohms, but the phones saw 1.8 ohms, meaning 99.2% less negative current feedback than from the standard resistor.
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| From | Salmon Egg <SalmonEgg@sbcglobal.net> |
|---|---|
| Date | 2014-02-10 00:26 -0800 |
| Message-ID | <SalmonEgg-1599B4.00261810022014@news80.forteinc.com> |
| In reply to | #56331 |
In article <ld9bu9$lo$1@dont-email.me>, J Burns <burns4@nowhere.com> wrote: > If the impedance of my phones varied from 20 to 170 ohms depending on > frequency, I could say a 220-ohm resistor in series had the effect of > negative current feedback. With my resistor network, the amplifier saw > more than 20 ohms, but the phones saw 1.8 ohms, meaning 99.2% less > negative current feedback than from the standard resistor. I do not fully understand this point. The impedance phones present at its terminals is from a combination of factors. There is the actual impedance of the internal driving network (voice coil) with the transducer blocked as modified by the loading of the diaphragm and the acoustic load of the air it drives. Adding large series resistance R turns a voltage feedback amplifier into a current source. That is, for an output voltage V the current through your phones approaches V/R as R increases no matter what the impedance of the phones are. It is the Norton equivalent resistance of the amplifier and the attached R. This is not negative current feedback because the current flowing in the output has no effect on the signal that ends up getting amplified. Depending upon the details of the phones, constant current drive may or may not end up giving improved performance over constant voltage drive. One thing the series resistance will do is prevent blowout of a low impedance voice coil when a loud passage occurs. Because a watt or two of sound is pretty loud in confined regions, a practical tradeoff is to have high power amplifiers with low efficiency speakers if the dissipation in the speaker circuitry improves (flattens) frequency response. -- Sam Conservatives are against Darwinism but for natural selection. Liberals are for Darwinism but totally against any selection.
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| From | J Burns <burns4@nowhere.com> |
|---|---|
| Date | 2014-02-10 11:39 -0500 |
| Message-ID | <ldavch$5fa$1@dont-email.me> |
| In reply to | #56337 |
On 2/10/14, 3:26 AM, Salmon Egg wrote: > In article <ld9bu9$lo$1@dont-email.me>, J Burns <burns4@nowhere.com> > wrote: > >> If the impedance of my phones varied from 20 to 170 ohms depending on >> frequency, I could say a 220-ohm resistor in series had the effect of >> negative current feedback. With my resistor network, the amplifier saw >> more than 20 ohms, but the phones saw 1.8 ohms, meaning 99.2% less >> negative current feedback than from the standard resistor. > > I do not fully understand this point. > > The impedance phones present at its terminals is from a combination of > factors. There is the actual impedance of the internal driving network > (voice coil) with the transducer blocked as modified by the loading of > the diaphragm and the acoustic load of the air it drives. Adding large > series resistance R turns a voltage feedback amplifier into a current > source. That is, for an output voltage V the current through your phones > approaches V/R as R increases no matter what the impedance of the phones > are. It is the Norton equivalent resistance of the amplifier and the > attached R. This is not negative current feedback because the current > flowing in the output has no effect on the signal that ends up getting > amplified. > > Depending upon the details of the phones, constant current drive may or > may not end up giving improved performance over constant voltage drive. > One thing the series resistance will do is prevent blowout of a low > impedance voice coil when a loud passage occurs. > > Because a watt or two of sound is pretty loud in confined regions, a > practical tradeoff is to have high power amplifiers with low efficiency > speakers if the dissipation in the speaker circuitry improves (flattens) > frequency response. > I'm not used to the phrase "negative current feedback." I supposed it could be used to protect the power transistors in an amplifier: if more output current were sensed, the signal would be reduced in the preamplifier. If you put a resistor in series with a loudspeaker and the signal voltage coming from the amplifier were constant, and the speaker impedance changed, the voltage at the speaker would vary inversely with the current. That sounds like the effect of negative current feedback. I have connected a sine-wave generator to an amp to check loudspeakers and phones. All were louder at certain frequencies. Current was minimal at those same frequencies. In other words, they produced sound more efficiently at resonance. Negative current feedback would mean increased voltage at resonant points, making them harsher and more mechanical sounding. That observation led me to make a low-impedance source for phones, as is normal for loudspeakers. I was rewarded.
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| From | Salmon Egg <SalmonEgg@sbcglobal.net> |
|---|---|
| Date | 2014-02-10 16:51 -0800 |
| Message-ID | <SalmonEgg-EBC71E.16515510022014@news80.forteinc.com> |
| In reply to | #56344 |
In article <ldavch$5fa$1@dont-email.me>, J Burns <burns4@nowhere.com> wrote: > I'm not used to the phrase "negative current feedback." I supposed it > could be used to protect the power transistors in an amplifier: if more > output current were sensed, the signal would be reduced in the preamplifier. > > If you put a resistor in series with a loudspeaker and the signal > voltage coming from the amplifier were constant, and the speaker > impedance changed, the voltage at the speaker would vary inversely with > the current. That sounds like the effect of negative current feedback. Consider an amplifier with high gain that has two input terminals for signal input. If a small fraction of the output 1/m of the output is fed back to subtract from the signal going into the amplifier terminals, the output would be about m times the input, irrespective of the actual high gain of the amplifier. That also means that the output voltage will be held almost constant even with load changes--low impedance output. If feedback is voltage from a sampling resister Rf times the current flowing in the load, then the output current would be almost Vin * Rf irrespective of load impedance. That is, like in an operational amplifier. the actual input to the real amplifier is near zero. This assumes that the amplifier is not driven into saturation by using extreme loads. > > I have connected a sine-wave generator to an amp to check loudspeakers > and phones. All were louder at certain frequencies. Current was > minimal at those same frequencies. In other words, they produced sound > more efficiently at resonance. Negative current feedback would mean > increased voltage at resonant points, making them harsher and more > mechanical sounding. That is true. Speaker cones driving air have resonance, series and parallel ones. The feedback signal can be a combination of voltage and current feedback. Such resonances can be from the room as well as the speaker suspension. > > That observation led me to make a low-impedance source for phones, as is > normal for loudspeakers. I was rewarded. -- Sam Conservatives are against Darwinism but for natural selection. Liberals are for Darwinism but totally against any selection.
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| From | J Burns <burns4@nowhere.com> |
|---|---|
| Date | 2014-02-13 05:48 -0500 |
| Message-ID | <ldi7tq$n9o$1@dont-email.me> |
| In reply to | #56377 |
On 2/10/14, 7:51 PM, Salmon Egg wrote: > In article <ldavch$5fa$1@dont-email.me>, J Burns <burns4@nowhere.com> > wrote: > >> I'm not used to the phrase "negative current feedback." I supposed it >> could be used to protect the power transistors in an amplifier: if more >> output current were sensed, the signal would be reduced in the preamplifier. >> >> If you put a resistor in series with a loudspeaker and the signal >> voltage coming from the amplifier were constant, and the speaker >> impedance changed, the voltage at the speaker would vary inversely with >> the current. That sounds like the effect of negative current feedback. > > Consider an amplifier with high gain that has two input terminals for > signal input. If a small fraction of the output 1/m of the output is fed > back to subtract from the signal going into the amplifier terminals, the > output would be about m times the input, irrespective of the actual high > gain of the amplifier. That also means that the output voltage will be > held almost constant even with load changes--low impedance output. > > If feedback is voltage from a sampling resister Rf times the current > flowing in the load, then the output current would be almost Vin * Rf > irrespective of load impedance. > If what you're sampling is output current (I), it will increase if load impedance decreases. So I/m, the negative feedback, will increase. Because it's negative feedback, the gain will vary in proportion to load impedance. If the amplifier gain is constant but you put resistance in series with a load whose impedance varies, the load will also see a voltage that varies with its impedance. In this case, voltage will be approximately output voltage times load impedance divided by the sum of load impedance and series resistance. (It won't be exactly that unless the phase of the load impedance is zero.)
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| From | Salmon Egg <SalmonEgg@sbcglobal.net> |
|---|---|
| Date | 2014-02-08 22:53 -0800 |
| Message-ID | <SalmonEgg-92A64E.22530608022014@news80.forteinc.com> |
| In reply to | #56189 |
In article <k-2dnfBzu9elyGjPnZ2dnUVZ8jadnZ2d@giganews.com>, Alan Browne <alan.browne@FreelunchVideotron.ca> wrote: > The other scam these days is "oxygen free copper audio loudspeaker > wire". This magic stuff (at a much higher cost) has 1% less R than > ordinary copper cable. Not audible at all - but the suckers are always > there... I am answering this snippet to 1. Comment on its content. 2. Move the topic to alt.engineering.electrical. There are a number of reasons to use oxygen free copper. Getting better performance for audio equipment is not one of them. The primary reason is to get the highest feasible electrical and thermal conductivities. Impurities like oxygen are imperfections of the crystal lattice. These impurities scatter electrons thereby reducing electrical conductivity. Electrons in alloys also contribute the heat conductivity. The imperfections also scatter phonons, quantized vibrations that transfer heat. Such copper was also used for vacuum tubes where you do not want materials to leak oxygen into the vacuum. Very pure copper is also good at cold welding, If you pull a vacuum through a copper tube, a modified bolt cutter will cold weld the tube shut. Probably, you do not need extreme purity to get good enough cold welds. To follow up, try using alt.engineering.electrical. -- Sam Conservatives are against Darwinism but for natural selection. Liberals are for Darwinism but totally against any selection.
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| From | Alan Browne <alan.browne@FreelunchVideotron.ca> |
|---|---|
| Date | 2014-02-09 09:16 -0500 |
| Message-ID | <vqSdnf1XPsUpEGrPnZ2dnUVZ_q2dnZ2d@giganews.com> |
| In reply to | #56277 |
On 2014.02.09, 01:53 , Salmon Egg wrote:
> To follow up, try using alt.engineering.electrical.
How's that working out for you?
--
Those who have reduced our privacy, whether they are state
or commercial actors, prefer that we do not reduce theirs.
- Jaron Lanier, Scientific American, 2013.11.
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| From | Salmon Egg <SalmonEgg@sbcglobal.net> |
|---|---|
| Date | 2014-02-05 19:16 -0800 |
| Message-ID | <SalmonEgg-CB1C99.19160905022014@news80.forteinc.com> |
| In reply to | #56049 |
In article <h-ydncr4CsadXG_PnZ2dnUVZ_uKdnZ2d@giganews.com>, Alan Browne <alan.browne@FreelunchVideotron.ca> wrote: > On 2014.02.05, 14:02 , Salmon Egg wrote: > > In article <gcy51p1vx8.fsf@ethel.the.log>, > > Doug Anderson <ethelthelogremovethis@gmail.com> wrote: > > > >>> So it does nothing? > >> > >> For audiophiles with really refined ears, the difference is like night > >> and day. > > > > It does something only with their imaginations. What does monster cable > > actually do? Can you compare the transfer function of monster cable to > > that of cheap speaker wire for a q0 or 20 foot run? What does it do for > > the shape of a square wave at 1 or 5 kHz? How big are the effects of > > using small speaker wires compared to room resonances in a typical audio > > "listening" room? We are not talking about an anechoic chamber that > > would have been in the former Bell Labs. > > > There are simple rules (formulae) for speaker impedance, wire run length > and power (for a given wire type such as copper) that put a lower bound > on the size of the wire. If the wire is that thickness or thicker, > you're done. To be conservative, if the calculation indicates 14 gauge, > for example, then one could use 12 gauge for additional margin. > > Wire coat hangars are just as good as 10 or 12 gauge wire, for example. In most cases, the worst that small speaker wires will do is to reduce the efficiency conversion from electrical power to acoustic power. These days, it is likely that flat speaker response comes from having speakers that are inefficient. That is speaker damping is used to flatten the transducer spectral output. You can buy a lot of energy for the price of monster cables. Without researching the topic, it is not clear what the effect will be by switching to coat hangers. Higher resistivity increases skin depth while higher permeabilitY decreases it. Either way, performance change is likely to be unnoticeable. Note however, that the wire on the voice coils is likely to be smaller than that in the speaker wire. -- Sam Conservatives are against Darwinism but for natural selection. Liberals are for Darwinism but totally against any selection.
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