The capsule of any normal condenser microphone can handle far higher sound pressure levels than the circuitry can. The maximum SPL is therefore the limit imposed by the circuitry. Above that limit there's a steady increase in distortion with rising input levels. But it isn't generally a "brick wall" (hard clipping) condition unless you have a saturating output transformer, and output transformers aren't used in most of the better microphones made in the past few decades.
The SPL at which the distortion starts to increase substantially isn't necessarily the manufacturer's stated maximum SPL, either, since some manufacturers are far more conservative in their ratings than others. If a microphone is conservatively rated then you can still get good sound quality somewhat above the specified level. I've measured microphones from Schoeps and Neumann and have found them to be quite conservatively rated.
I believe, however, that most other manufacturers aren't as conservative with their ratings. And while I've never measured a DPA microphone, I wouldn't group that company with Schoeps or Neumann with regard to measurement and specification practices in general. They measure things "their way." Unfortunately this can make for real problems if you try to compare their published specifications with those of other manufacturers. I am sorry to say that, because their microphones are excellent without a doubt, and of course their original parent company (B & K) has been famous for decades as a supplier of acoustical measurement equipment.
--I'm attaching a graph that I made a few years back when I compared two older Neumann microphone bodies, one modified and one stock. The trace at the bottom shows the stock microphone. You can see that at 6 dB above its rated limit of 120 dB SPL (equivalent), the unmodified microphone is still doing quite nicely. A few dB later, transformer saturation starts to set in and by 130 dB SPL (equivalent), the distortion reaches a level that I would rather avoid.
Schoeps and Neumann transformerless microphones tend to be rated at ca. 130 dB SPL for 0.5% or lower THD; if you accept 1% (as I would do), you can add a few dB more to that number. I can't hear less than about 3% low-order THD, so I see nothing wrong with using 1% as the standard rather than 0.5%. I think that the 0.5% limit (which isn't mandated in any standard--it's just industry practice since the end of the vacuum-tube era) came about only because microphone manufacturers back in the 1970s felt embarrassed to be quoting a 1% distortion spec in an era when some hi-fi amplifiers were quoting 0.001% distortion or even lower.
--best regards
Topic: Comparing "Max SPL @ 0.5% & 1% THD" ratings with "Max Peak"? (Read 2916 times)