Topic: SPL question for someone in the know...

[guysonic]

170 Cycles mic in with the -20 att engaged, this is into an Oade mod'ed mic input.  The mic in can easily handle DPA406X series mic output, CSB output which are well above the output level of the DSM/PA-6LC3B combo, the level knob at no lower than 7.  DiStOrTiOn.  The wavform shows signs of capsule failure, not brickwalling, it's probably attributed to the lower bias voltage use to power the mics (1.5v).  While they sound much better than a simple rev-polarity modified WM capsule running on 9v they just can't hang with higher SPL's, esp. lower frequencies.
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Clarification of having Oade deck mod confirms first stage mic-amp input is most robust for high level output mics.  Oade sometime changed the mic input powering scheme, but this powering mod proved not very suitable for direct DSM mic powering and could cause the mic to distort at lower SPL levels.  However, if using correct PA powering adapter with the Oade mod'd input, then the bass distortion is likely not from the mic amp, but the mic itself getting overloaded as mentioned.   This indicates likely 'peak' bass SPL over 134 dB SPL where DSM-6S/EL mics are not their usual clean sounding self.   

[Genghis Cougar Mellen Khan]

Clarification of having Oade deck mod confirms first stage mic-amp input is most robust for high level output mics.  Oade sometime changed the mic input powering scheme, but this powering mod proved not very suitable for direct DSM mic powering and could cause the mic to distort at lower SPL levels.  However, if using correct PA powering adapter with the Oade mod'd input, then the bass distortion is likely not from the mic amp, but the mic itself getting overloaded as mentioned.   This indicates likely 'peak' bass SPL over 134 dB SPL where DSM-6S/EL mics are not their usual clean sounding self.   

I am referring to DSM-6s/EL into the PA6-LC3B power module into mic input w/the -20 att engaged and the levels easily above 7.  The Oade mod is the basic mod that improves the unit's input handling capabilities.  I would be very suprised it SPL levels were above 120db in some of the locations/venues that had recordings that resulted in low end bass distortion, one instance behind the board aprox 60' from the stage, the other in the first row of the balcony which is at least 100' away.  The mics may be able to handle 134db SPL in higher frequencies, but at lower frequencies I don't believe they have such a capability.

A test tone, one hell of a subwoofer setup and a SPL meter would be a good test, I'm guessing the results would show that the lower frequency handling of the DSM mics is well below 134db SPL threshold.

[guysonic]

Clarification of having Oade deck mod confirms first stage mic-amp input is most robust for high level output mics.  Oade sometime changed the mic input powering scheme, but this powering mod proved not very suitable for direct DSM mic powering and could cause the mic to distort at lower SPL levels.  However, if using correct PA powering adapter with the Oade mod'd input, then the bass distortion is likely not from the mic amp, but the mic itself getting overloaded as mentioned.   This indicates likely 'peak' bass SPL over 134 dB SPL where DSM-6S/EL mics are not their usual clean sounding self.   

I am referring to DSM-6s/EL into the PA6-LC3B power module into mic input w/the -20 att engaged and the levels easily above 7.  The Oade mod is the basic mod that improves the unit's input handling capabilities.  I would be very suprised it SPL levels were above 120db in some of the locations/venues that had recordings that resulted in low end bass distortion, one instance behind the board aprox 60' from the stage, the other in the first row of the balcony which is at least 100' away.  The mics may be able to handle 134db SPL in higher frequencies, but at lower frequencies I don't believe they have such a capability.

A test tone, one hell of a subwoofer setup and a SPL meter would be a good test, I'm guessing the results would show that the lower frequency handling of the DSM mics is well below 134db SPL threshold.

It is true that the original SPL handling testing for DSM-6S/EL models was not done at lower bass frequency, but at mid-bass 100 cycles using a small sealed chamber pressurized by 40 mm headphone type speaker.

I have heard one recorded DAT tape from dissatisfied customer using verified good condition DSM-6S/EL + PA-6LC3B with muddy sounding (distorted) bass using standard D8 deck. But this was recorded within 15 feet from stage at a Nine-Inch Nails extreme loudness metal rock venue!

To fully qualify low frequency high SPL ability with the particular DSM set related to in your experience, it is important to know for certain a few details. 

1.) was this actually a good working condition DSM-6S/EL model? (original owner's name + set's serial number helps look up the model/calibration record for this particular set)

2.) was the PA-6LC3B being used with good condition ONLY alkaline type battery, and was this battery properly installed with correct cell polarity?   

Verifying these details helps eliminate known-to-happen variables that easily lead to well intentioned, but misleading conclusions about a microphone's typical low frequency SPL handling ability. 

From a few customer experiences, I usually do not recommend using DSM-6S/EL for recording extreme bass loudness heavy metal venues at close up against the stage/speaker positions, but heard no complaints at moderate distances

I will relate that these very same high SPL handling 6S/EL models have been placed INSIDE THE ENGINE COMPARTMENT of unmufflered RACE CARS/BOATS (stationary/driven) by sound designers at Sounddeluxe in Toronto with excellent results by all accounts.     No other mic they tried (and they have almost unlimited choice of mics to work with) worked to produce clear and also low noise (unaffected by the 50,000+ high voltage ignition) engine recordings.