how high is a snare drum's peak SPL? - Page 2

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Phil Allison wrote:

> YOU are simply NOT sane.
>
> A massive embarrassment to your employers.

Oh sure ! La Di da !

And you're a massive embarrassment to Usenet !

Graham

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In article <dd0if9$lc6$1@panix2.panix.com>, kludge@panix.com says...

> Sadly, we have been here before with Phil. You might want to do a google
> search and see the basic responses from when he first showed up here a
> few months ago. I figure the best thing to do is killfile him and not
> worry about it.
> --scott

Yeah, and if you search his email address, you'll find that he's decided
that many other forums he's posted to are filled with <expletive
deleteds> as well. Clearly, he either gets off on this kind of ranting,
which is sick, or can't stop himself, which is sad. One can only hope
he doesn't treat the people he knows in person this way.

-Pete

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"Paul Stamler"


** Stamler is proven incorrigible LAIR and utter know nothing fool.

>
> The fact is that the dB was defined very carefully as relating to power,
> and
> only to power. And that, soon afterwards, people started using it
> differently, until now, almost everyone uses it differently.


** Utter bullshit - the modern use of dBs still all relate to power.

A change of +3 dB always means a doubling of * power level * at the point
of measurement.

+ 3dB is never a doubling of voltage, pressure or current.




........... Phil

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In article <3lj6t9F11tj9tU1@individual.net> philallison@tpg.com.au writes:

> A change of +3 dB always means a doubling of * power level * at the point
> of measurement.

There are times when we don't want to measure power or change in
power. At those times, we (the people) say that doubling the
* voltage level * is a change of +6 dB. We don't argue with those who
say that the * power level * has also doubled, we just don't care.

If you think this a lie, please consult your dictionary for a
definition of the word "lie" before posting your usual response.





--
I'm really Mike Rivers (mrivers@d-and-d.com)
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

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Phil Allison wrote:

> "Bob Cain"
> > Phil Allison wrote:
> >
> >> + 3dB is never a doubling of voltage, pressure or current.
> >
> > You obviously can't read because no one has said it ever is.
>
> ** Many have alluded to such an idea with the false assertion the dBs are
> used for quantities other than power. I am still waiting for an valid
> example.

Since someone else posted a reference to op-amps data sheets to make another
point in this thread, how about this ?

Avd – Differential Voltage Amplification – dB

Figures 12,13 and 14

kSVR – Supply Voltage Rejection Ratio – dB

Figure 16

focus.ti.com/general/docs/lit/getliterature.tsp?genericPartNumber=op27&fileType=pdf



So I guess TI ( and all the other semiconductor manufacturers ) are wrong
too ?


Graham

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RD Jones wrote:

> Phil Allison wrote:
>
> > ** Many have alluded to such an idea with the false assertion the dBs are
> > used for quantities other than power. I am still waiting for an valid
> > example.
>
> Digital ?
>
> Most meters I have seen on PC screens are calibrated
> in "dB", yet there is no power _OR_ voltage being
> transfered, sourced, or loaded. There is no loss or
> loading since the numbers should remain the same when
> tranfering the data from one file to another.

Does that mean there is such a thing as 'perfect digital matching' ?

Of course if it could be loaded / terminated would you lose half the bits ?
;-)

Graham

Archived from groups: rec.audio.pro (More info?)

Graham Stevenon = Studiomaster's Biggest Enemy
>
> Phil Allison wrote:
>>
>> >> + 3dB is never a doubling of voltage, pressure or current.
>> >
>> > You obviously can't read because no one has said it ever is.
>>
>> ** Many have alluded to such an idea with the false assertion the dBs are
>> used for quantities other than power. I am still waiting for an valid
>> example.
>
> Since someone else posted a reference to op-amps data sheets to make
> another
> point in this thread, how about this ?
>
> Avd - Differential Voltage Amplification - dB
>
> Figures 12,13 and 14
>
> kSVR - Supply Voltage Rejection Ratio - dB
>
> Figure 16
>
> focus.ti.com/general/docs/lit/getliterature.tsp?genericPartNumber=op27&fileType=pdf
>
>
> So I guess TI ( and all the other semiconductor manufacturers ) are wrong
> too ?
>


** Are the dB figures shown based on the formula:

dB = 20.log v1 / v2 ??

( same as dB = 10.log v1squared / v2 squared )


Seems they are.

So dBs are being used for power ratios.






........... Phil

Archived from groups: rec.audio.pro (More info?)

Phil Allison wrote:


> ** But once the data is converted to analogue the dB readings will refer to
> relative power as per usual.

Just as those 'voltage ratios' do when using a
stated, known, or standard (600 Ohm) load will.

rd

Archived from groups: rec.audio.pro (More info?)

Phil Allison wrote:

> Graham Stevenon = Studiomaster's Biggest Enemy
> >
> > Phil Allison wrote:
> >>
> >> >> + 3dB is never a doubling of voltage, pressure or current.
> >> >
> >> > You obviously can't read because no one has said it ever is.
> >>
> >> ** Many have alluded to such an idea with the false assertion the dBs are
> >> used for quantities other than power. I am still waiting for an valid
> >> example.
> >
> > Since someone else posted a reference to op-amps data sheets to make
> > another
> > point in this thread, how about this ?
> >
> > Avd - Differential Voltage Amplification - dB
> >
> > Figures 12,13 and 14
> >
> > kSVR - Supply Voltage Rejection Ratio - dB
> >
> > Figure 16
> >
> > focus.ti.com/general/docs/lit/getliterature.tsp?genericPartNumber=op27&fileType=pdf
> >
> >
> > So I guess TI ( and all the other semiconductor manufacturers ) are wrong
> > too ?
> >
>
> ** Are the dB figures shown based on the formula:
>
> dB = 20.log v1 / v2 ??
>
> ( same as dB = 10.log v1squared / v2 squared )
>
> Seems they are.
>
> So dBs are being used for power ratios.

Not at all.

Which part of *Voltage Amplification - dB* wasn't apparently clear to you.

Op-amp data sheets are most certainly NOT talking about power gain.

Graham

Archived from groups: rec.audio.pro (More info?)

> Graham Stevenon = Studiomaster's WORST Enemy
>>
>> > Phil Allison wrote:
>>
>> ** Are the dB figures shown based on the formula:
>>
>> dB = 20.log v1 / v2 ??
>>
>> ( same as dB = 10.log v1squared / v2 squared )
>>
>> Seems they are.
>>
>> So dBs are being used for power ratios.
>
> Not at all.



** You simply have no case and cannot answer my points.

You are an unbelievably stupid, insightless autistic.





.......... Phil

Archived from groups: rec.audio.pro (More info?)

I just wanted to go on record as saying that I think there IS a
fundamental difference between the sound of say a Bode frequency
shifter which suppresses the lower sidebands and a ring modulator,
which doesn't. The ring mod gets extra grunk from the fact that
resulting spectral components of e.g. a harmonic source can actually
wind up being VERY close together, while in a frequency shifter they
just shift up by a fixed # of Hz.

I actually wanted to post a real question in here but these threads are
kinda like driving past a car accident!

Archived from groups: rec.audio.pro (More info?)

Phil Allison wrote:

>>>in my quest for a better sounding close snare mic, i'm gonna give a
>>>josephson c42 a try. a 57 is not giving me what i want. i emailed
>>>josephson asking if i should get the c42H high level version instead of
>>>the standard one, and they suggested trying the standard first, as the
>>>high level version is a lot noisier, thus reducing it's usefulness on
>>>quieter sources. how high do snare drum peaks get, worst case SPL with
>>>the mic within 3-5 inches? say a 300 pound drummer with 2B sticks
>>>hammering a loud brass shell snare, hitting a rimshot. the standard
>>>c42 clips at 135 dB SPL. the c42H can do 155! thanks.
>>
>>First of all, I don't think you'll exceed 135 dB SPL. Also you should
>>note
>>that this is a spec _across the band_. It's worst case... midrange
>>frequencies can probably go well above that before the mike clips.
>
<snip>
>
> Since when does the pre-amp in a condenser mic have a clipping level that
> varies with at an audio frequency ????
>
> Never.

Not never. Seldom (principally in microphones with equalization in the
electronics, not with the C42) but not never. But, since you're not
connecting to the preamp but rather putting sound into the capsule, it's
irrelevant -- the clipping level of the entire microphone is the
specification of interest.

> The C42 is speced at 8.5mV / uBar and the C42 H is 0.8mV/ uBar - so, 135
> dB SPL corresponds to an output of 0.95 volts from the C42 and 0.095 volts
> from the C42H.

Your numbers are right but the units aren't. The C42 free field
sensitivity is 8.5 mV/Pascal. 1 Pascal (not 1 microbar) is 94 dB SPL. 1
microbar, or 1 dyne per square centimeter, is 0.1 Pa or 74 dB SPL. 135
dB SPL is 41 dB more than 1 Pascal, or 112 times the voltage. 8.5 mV
times 112 is 0.95 volts. The electronics of the C42 exceed 1% harmonic
distortion at about this level (about 2.8 volts peak-to-peak, open
circuit, with real IEC spec P48 phantom power). Actual clipping level is
somewhat higher, typically 8 to 10 dB for impulse waveforms like drum hits.

Frankly the concern about mics clipping at high SPLs isn't really
warranted. Most modern condenser microphone capsules such as those in
our C42 are undamaged to at least 160 dB SPL. It is very seldom that
even the loudest snare reaches 130 dB. As we responded to the original
inquiry mentioned in this thread, try a regular mic first. If you really
think you need a higher SPL ratings, we have the C42H and the e22S,
which is specifically designed for close-up drum and other pickups.

--
David Josephson * Josephson Engineering, Inc. * www.josephson.com