Loudness calibration?
Ken S. Tucker
for instance most phono amps have a 0-10 knob, so if
I put in a signal into the phono input I get a Loudness
out the speaker.
Here's the background,
I design and QC the manufacture of specialized
microphones such as,
http://www.trak4.com/earco/index.html
Recently I was asked to produce a specification as to
db gain, distortion, stuff like that, but I found for this
application the spec is subjective.
You can review "loudness" here,
http://en.wikipedia.org/wiki/Loudness
and read about the subjectivity.
The EAR has a built in distortion (filter) to accentuate
the 2khz-4khz range that is subjectively agreeable,
to test subjects.
When the Amp Volume is set to 2-3 gives normal hearing,
through indoor speakers, 5 is the usual comfort setting,
7-8 provides the sound of a car a 1/4 mile away, max 10
brings up a slight hum, like 60cycle from the inside amp
and super loundness.
So I'm wondering if there's some 'rule of thumb' spec to
ratio amplification from 0,1,2...10?
TIA
Ken
Frank Buss
> Is there a specification for phono amps volume control,
> for instance most phono amps have a 0-10 knob, so if
> I put in a signal into the phono input I get a Loudness
> out the speaker.
>
> Here's the background,
> I design and QC the manufacture of specialized
> microphones such as,
> http://www.trak4.com/earco/index.html
>
> Recently I was asked to produce a specification as to
> db gain, distortion, stuff like that, but I found for this
> application the spec is subjective.
>
> You can review "loudness" here,
> http://en.wikipedia.org/wiki/Loudness
> and read about the subjectivity.
You are right, the loudness is a bit subjectiv, if you some music. If you
use a sine signal and measure the audio pressure level, or the relative
change for knob position 0-10 in something like dBU or dB(SPL), and the
distortion of the signal in THD or something similar, it is objective:
http://en.wikipedia.org/wiki/Decibel
> The EAR has a built in distortion (filter) to accentuate
> the 2khz-4khz range that is subjectively agreeable,
> to test subjects.
Yes, this is the reason e.g. for dB(A), or the new standard ITU BS.1771.
> So I'm wondering if there's some 'rule of thumb' spec to
> ratio amplification from 0,1,2...10?
You should read some basics about dB, first.
--
Frank Buss, f...@frank-buss.de
http://www.frank-buss.de, http://www.it4-systems.de
Vladimir Vassilevsky
Ken S. Tucker wrote:
> Is there a specification for phono amps volume control,
> for instance most phono amps have a 0-10 knob, so if
> I put in a signal into the phono input I get a Loudness
> out the speaker.
> So I'm wondering if there's some 'rule of thumb' spec to
> ratio amplification from 0,1,2...10?
In my experience, it is all perception based and it also depends on the
particular acoustic arrangement. The good initial guess is the log
scale, however it has to be optimized: the curve should be more steep at
low volume, and less steep at high volume. Balance, Fade and Tone
control curves are entirely different story.
Vladimir Vassilevsky
DSP and Mixed Signal Design Consultant
http://www.abvolt.com
Rich Grise
> Is there a specification for phono amps volume control, for instance most
> phono amps have a 0-10 knob, so if I put in a signal into the phono input
> I get a Loudness out the speaker.
> ...
> So I'm wondering if there's some 'rule of thumb' spec to ratio
> amplification from 0,1,2...10?
Kinda. Use an "audio taper" pot. That will make the 1-10 "appear" linear
(i.e., 4 is "twice as loud" as 2, and so on.)
But you should label your knobs up to 11, for all the obvious reasons. ;-)
Cheers!
Rich
Ken S. Tucker
Another new standard, I'll read up on that.
> > So I'm wondering if there's some 'rule of thumb' spec to
> > ratio amplification from 0,1,2...10?
>
> You should read some basics about dB, first.
Yeah, I'm guessing volume controls are all log taper,
we found about 20dB gain over human hearing, using tables,
from about 2 to 8, a difference of 6, so at 3 db per unit volume,
from 2 that's 18dB, we spec 20dB so that's ok.
> Frank Buss, f...@frank-buss.dehttp://www.frank-buss.de,http://www.it4-systems.de
Regards
Ken
Ken S. Tucker
> Ken S. Tucker wrote:
> > Is there a specification for phono amps volume control,
> > for instance most phono amps have a 0-10 knob, so if
> > I put in a signal into the phono input I get a Loudness
> > out the speaker.
> > So I'm wondering if there's some 'rule of thumb' spec to
> > ratio amplification from 0,1,2...10?
>
> In my experience, it is all perception based and it also depends on the
> particular acoustic arrangement. The good initial guess is the log
> scale, however it has to be optimized: the curve should be more steep at
> low volume, and less steep at high volume. Balance, Fade and Tone
> control curves are entirely different story.
Yes we did tone generation to a speaker a distance
away from the mic, read the output to the speaker on
sillyscope channel1 and compared to channel2 input
from speaker and got lot's of pretty graphs and tables,
but in the end, it was all set subjectively, by ear.
> Vladimir Vassilevsky
> DSP and Mixed Signal Design Consultanthttp://www.abvolt.com
**sounds** good.
Ken
Ken S. Tucker
> On Thu, 29 Oct 2009 11:39:15 -0700, Ken S. Tucker wrote:
> > Is there a specification for phono amps volume control, for instance most
> > phono amps have a 0-10 knob, so if I put in a signal into the phono input
> > I get a Loudness out the speaker.
> > ...
> > So I'm wondering if there's some 'rule of thumb' spec to ratio
> > amplification from 0,1,2...10?
>
> Kinda. Use an "audio taper" pot. That will make the 1-10 "appear" linear
> (i.e., 4 is "twice as loud" as 2, and so on.)
Yeah that sounds good, the useful range is from 2 to 8.
> But you should label your knobs up to 11, for all the obvious reasons. ;-)
Thank you Rich, I've been married for 40 years, my knobs gets to 10.5
it's wore down.
> Cheers!
> Rich
Same.
Les Cargill
<snip>
>
> So I'm wondering if there's some 'rule of thumb' spec to
> ratio amplification from 0,1,2...10?
> TIA
> Ken
>
There's the Tufnel Protocol:
http://www.youtube.com/watch?v=hN5SCRvhMtk
<snip>
--
Les Cargill
mpm
Have you considered trying that little blue pill? :)
Phil Allison
"Ken S. Tucker"
>
> Is there a specification for phono amps volume control,
> for instance most phono amps have a 0-10 knob, so if
> I put in a signal into the phono input I get a Loudness
> out the speaker.
>
> Here's the background,
> I design and QC the manufacture of specialized
> microphones such as,
> http://www.trak4.com/earco/index.html
** So the mic is actually plugged into the " phono " input on a domestic
amplifier ?
You have compensation for the bass boost and treble cut characteristics (
RIAA curve ) of such inputs ??
.... Phil
Ken S. Tucker
> "Ken S. Tucker"
>
>
>
> > Is there a specification for phono amps volume control,
> > for instance most phono amps have a 0-10 knob, so if
> > I put in a signal into the phono input I get a Loudness
> > out the speaker.
>
> > Here's the background,
> > I design and QC the manufacture of specialized
> > microphones such as,
> >http://www.trak4.com/earco/index.html
>
> ** So the mic is actually plugged into the " phono " input on a domestic
> amplifier ?
Yes, that's because nearly everyone has (or can get) an amp
with a phono input to drive their speaker(s), so it's convenient.
About 1/2 of our customers order a 2nd unit after using the 1st
to get stereo and/or more coverage like the front and backyard.
> You have compensation for the bass boost and treble cut characteristics (
> RIAA curve ) of such inputs ?
Partly, the EAR has a soft filter (rounded Q) that favors 3khz,
which is where nature sounds dominate, after that we advise
adjusting the treble/bass or equalizer for compensation, so a
bird chirp is accentuated, unless you want human voice.
At the EARco site, near the bottom are loon calls, you can hear,
http://www.trak4.com/earco/index.html
they were tape recorded then later digitized, and has the echo
from terrain around the lake.
You'll laff but a standard we employed to set up the circuit was
to play our favorite tunes to the EAR and then make sure the
quality was good, because the human ear can detect too much
distortion using a familiar song.
((That's a design secret so don't tell anybody)).
Thanks all
Ken
Ken S. Tucker
> On Oct 29, 3:39 pm, "Ken S. Tucker" <dynam...@vianet.on.ca> wrote:
> > On Oct 29, 11:01 am, Rich Grise <richgr...@example.net> wrote:
> > > But you should label your knobs up to 11, for all the obvious reasons. ;-)
> > Thank you Rich, I've been married for 40 years, my knobs gets to 10.5
> > it's wore down.
A bit OT, but the EARco site did mention romance in a social setting.
Personally, I'm in favor of trying new things, but I'd be inclined to
discuss things of that nature in another group or thread, to share.
Ken
Nemo
>you should label your knobs up to 11, for all the obvious reasons. ;-)
This reminds me of a story from university:
A group of students sharing a house had one member who was very proud of
his super audio system (this is back in the early 80's when hifi power
and distortion was a status symbol, before cheap stuff became good). He
would often retire to his room and turn the volume up irritatingly loud,
claiming that it sounded best at a volume setting of 7 or so.
Eventually the other lads raided his room while he was out and wired
some power 8 ohm resistors in series with his speakers. They were 4 or 8
ohm speakers.
After this everyone was happy; he believed he was still getting the
ideal volume; the others could hear themselves speak, etc. This went on
for a year, until he noticed smoke coming out the back of one of his
speaker cabinets and opened it up to find a charred resistor.
--
Nemo
Jim Thompson
Reminds me of a person at Motorola... obnoxiously loud on the
telephone. One day I went into his office with a circular piece of
thin black cardboard, unscrewed the mouthpiece, inserted cardboard,
probably 10dB of attenuation. He never did notice ;-)
...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
Liberal, Leftist and Democrat are polite aphorisms for YELLOW.
Phil Hobbs
> On Wed, 11 Nov 2009 20:35:23 +0000, Nemo
> <z...@nospam.nospam.nospam.nospam.co.uk> wrote:
>
>> Rich Grise mentions
>>
>>> you should label your knobs up to 11, for all the obvious reasons. ;-)
>> This reminds me of a story from university:
>>
>> A group of students sharing a house had one member who was very proud of
>> his super audio system (this is back in the early 80's when hifi power
>> and distortion was a status symbol, before cheap stuff became good). He
>> would often retire to his room and turn the volume up irritatingly loud,
>> claiming that it sounded best at a volume setting of 7 or so.
>>
>> Eventually the other lads raided his room while he was out and wired
>> some power 8 ohm resistors in series with his speakers. They were 4 or 8
>> ohm speakers.
>>
>> After this everyone was happy; he believed he was still getting the
>> ideal volume; the others could hear themselves speak, etc. This went on
>> for a year, until he noticed smoke coming out the back of one of his
>> speaker cabinets and opened it up to find a charred resistor.
>
> Reminds me of a person at Motorola... obnoxiously loud on the
> telephone. One day I went into his office with a circular piece of
> thin black cardboard, unscrewed the mouthpiece, inserted cardboard,
> probably 10dB of attenuation. He never did notice ;-)
>
> ...Jim Thompson
In my old job, some moron decided that they should put horn loudspeakers
in every lab, just so deaf people working with their ears pressed up to
cryopumps would be able to hear safety announcements. The result was
that every time there was a blood drive, or some management droid was
coming to give a talk, I got my ears blasted. Of course putting in a
resistor would have been Officially Frowned Upon.
So, I went to the stockroom and got a small selection of rubber test
tube stoppers, opened up the speaker, crammed a stopper down the horn,
and put it back together. Announcements were still more than audible,
and I didn't run the risk of sticking a soldering iron into my leg.
I noticed that quite a few labs seemed much quieter after a few weeks.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot net
http://electrooptical.net
Jan Panteltje
<z...@nospam.nospam.nospam.nospam.co.uk> wrote in
<u$Cs8bDLA...@furfur.demon.co.uk>:
I had a Philips HiFi (was written on it) transistor amplifier.
It had 2 connectors for loudspeakers,
one for 4 Ohm speakers, and one for 8 Ohm speakers.
The 4 Ohm speaker connector was connected inside via a 4 Ohm resistor to
the 8 Ohm speaker connector, that one was connected to the amplifier output.
Damping? What damping? Power? What power?
Jim Thompson
Widlar's method"
"Plumber's helper", held "cup" end up.
Add lighted cherry bomb into "cup".
Hold "cup" against ceiling speaker until discharged ;-)
I kid you not, Widlar really did this... source of information: Jim
Foster, my technician for many years, worked at National when I left
Philco-Ford, until I could hire him back to Motorola ;-)
krw
I was an attendee at Intel's announcement of the iAPX432 in the Grand
Hyatt in NYC. The hotel was brand new at the time and nothing worked
right, elevators going to the wrong (non-existent) floor, etc. During
the announcement festivities the fire alarms went off, several times.
One of the Intel execs finally had enough and took a swing at the horn
with a chair. The horn flew across the room, but after it landed was
quite silent. The speaker made some comment about RHIP.