Topic: Microphone Input-Noise Comparison at max. gain setting

[JM Charcot]

Ooops sorry didn't read it... 

[DSatz]

Arni99, even a stopped clock is right twice a day (unless it's a 24-hour clock)--and as we saw in the Edwards case last week, sometimes even the National Enquirer gets a story right.

All I'm saying is that the method as described isn't valid. That doesn't mean that every single finding will be wrong in a predictably patterned way; there isn't a systematic bias. It only means that many if not most of the results will probably be wrong more or less at random. Unfortunately you can't tell in advance which cases those will be, or which direction they'll be wrong in, or by how much. The individual data points are presumably real, but they've been collected in a way that makes them garbage as a set.

I've spent a fair amount of time trying to make reliable measurements of professional and semi-professional mike preamps. It's not easy! Interpreting and comparing the results isn't simple, either.

I believe in the slogan "Make things as simple as possible, but no simpler." Noise measurements are a very good example of a subject that shouldn't be made simpler than it actually is.

--best regards

[Arni99]

Arni99, even a stopped clock is right twice a day (unless it's a 24-hour clock)--and as we saw in the Edwards case last week, sometimes even the National Enquirer gets a story right.

All I'm saying is that the method as described isn't valid. That doesn't mean that every single finding will be wrong in a predictably patterned way; there isn't a systematic bias. It only means that many if not most of the results will probably be wrong more or less at random. Unfortunately you can't tell in advance which cases those will be, or which direction they'll be wrong in, or by how much. The individual data points are presumably real, but they've been collected in a way that makes them garbage as a set.

I've spent a fair amount of time trying to make reliable measurements of professional and semi-professional mike preamps. It's not easy! Interpreting and comparing the results isn't simple, either.

I believe in the slogan "Make things as simple as possible, but no simpler." Noise measurements are a very good example of a subject that shouldn't be made simpler than it actually is.

--best regards

Your own ears are the best instrument for "measuring" , in my case it´s not hard to tell the RH1 has the best internal preamp for silent sources.
Its up to the professionals to do real, objective measurements. I don´t have the knowledge, but I got ears that tell me which recorder to use for which recording situation and in the end that´s what it´s all about after 21 years of taping.
 

[digifish_music]

Arni99, even a stopped clock is right twice a day (unless it's a 24-hour clock)--and as we saw in the Edwards case last week, sometimes even the National Enquirer gets a story right.

I've spent a fair amount of time trying to make reliable measurements of professional and semi-professional mike preamps. It's not easy! Interpreting and comparing the results isn't simple, either.

I believe in the slogan "Make things as simple as possible, but no simpler." Noise measurements are a very good example of a subject that shouldn't be made simpler than it actually is.

--best regards

For subjective listening tests, I have found the biggest issue with comparisons are:

1. Finding a constant noise source that is interesting to listen to and spans the frequency spectrum in ways that your intended audience would use the preamp (i.e valid source).
2. Level matching.

If you are testing preamps, then multi-track recorders are your friend since parallel recording will allow you to make direct comparisons of the same source material (see my crude attempt at this here, last recording on the initial post).

If you are testing recorders, then you really need to record the same source under controlled conditions (IMO). Although how necessary this is depends on how close the recorders are, the R44 vs R09HR internal mic comparison for example is blindingly obvious.

But it means to do it correctly you need 2 sets of identical stereo micsa and there are now 4 permutations of mic and preamp to use: Pre1 + Mic-set A vs Pre 2 + Mic-set A vs Pre 2 + Mic-set B vs Pre 2 + Mic-set B.

From my reading of the auditory psychoacoustic literature one of the most sensitive listening conditions is relatively fast A/B switching with less than 7 second samples of material and no gaps or loud noises at the junctions. I used 2 in my example, but 3 probably is better since it takes a while to focus your attention on particular details.

digifish

[Ozpeter]

Seems to me there are two issues here - first, people want the best regardless of actual requirement, so the interest in making these comparisons is understandable.  However, the real issue is "what problems can you hear with your equipment in actual normal use?"  - and I strongly suspect that these days, when recording live music, preamp noise is unlikely to be an issue other than with really cheap and nasty equipment.

I record classical music.  When I look at the meters between movements, with levels set so that the loudest parts of the performance will peak to close to 0dB, typically they are flickering around -55dB at best.  If I bury the mic under a pile of blankets in a quiet room at night, I might see the meters hover around -85dB.  In other words, the ambient noise of a performance space is normally way above the noise floor of the equipment.

So, avoid the few preamps that might be identified by measurement or reputation as significantly worse than the rest, and you'll probably be perfectly happy with the performance of the rest under real world music recording conditions.

Or am I being unrealistically complacent?