At 9:42 AM -0400 7/6/06, Walter Knapp wrote:
>Posted by: "cfmspencer"
>> yes, I know they are not related,
>> I was simply seeking a sort of calculated
>> formula that included what I thought to be
>> the two most important specifications for
>> nature recording into a single number for
>> a relative ranking (of sorts). certainly
>> not scientific
>That's really the point, they are two more or less independent
>specifications. As far as single numbers they are probably the most
>important for nature recording. I also consider things like the
>character of the polar patterns to be very important too. In other words
>don't get hung up on just those two numbers, look at the mic as a whole.
>As you can tell from the numbers you are getting combining the two can
>be pretty misleading.
It looks like the chart is partially designed to show how Rane's mic
pre with a noise floor -128dBU is low enough for almost any mic. For
example, the Rode NT1-A's noise output at -118dBu would be 10dBu
louder-- right at the10dBu separation they suggest in needed for mic
The accuracy of the manufacturer's specs are a weak link in using
numbers in general, but as a reference tool for learning about the
drawbacks of lower quality mic pre, Chart 3 has been instructive for
The compound numbers I get from the chart for Clay's examples,
-98dBu for the Sanken (20 dBA and 50mV/Pa)
-111 dBu for the Sennheiser (12 dBA and 25 mV/Pa)
seem about right to me.
>The preponderance of discussion in this group seems to have become
>discussing specs or doing simplistic tests.
I believe Clay is in the process of investing in expensive mics.
Have a productive trip to Florida. In the not so far future, I hope
to have more control over my time. This afternoon I'm pulling off a
rotten back porch and tonight I'll be meeting with students from 4pm
to 11pm. I have generated about 500GB's of 24/48K 4 ch surround
recordings over this last year though. Rob D.
> It would be good to see a
>lot more discussion of actual field recording, some sound like they
>hardly get out and record, and thats really the point of nature
>recording. I do try and push folks to step out the door and get going on
>nature recording as that's where the majority of the learning and info
>about equipment comes from.
>Putting my money where my mouth is I'm off to Florida for a bit of field
>work today. If you have more questions of me they will have to wait.