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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => LAB Lounge => Topic started by: Dave Potter on July 07, 2011, 11:10:21 am

Title: No SPL figures for dynamic mics?
Post by: Dave Potter on July 07, 2011, 11:10:21 am
I notice that of the specs for dynamic mics (that I have looked at), there is no figure for SPL whereas condenser mic usually state this.  What is the reason?
Title: Re: No SPL figures for dynamic mics?
Post by: Geoff Doane on July 07, 2011, 12:59:01 pm
I notice that of the specs for dynamic mics (that I have looked at), there is no figure for SPL whereas condenser mic usually state this.  What is the reason?

Do you mean maximum SPL?

It may not be common, but it's not unheard of.  AKG used to list this spec in their 1980s catalogs, and certain other mics (EV RE20 and Sennheiser MD421) have listed it, although the 421 was something like "no overload point".

The spec may not be as common because with no electronics to clip, the overload point is not so easily defined.  How much distortion is too much?

GTD
Title: Re: No SPL figures for dynamic mics?
Post by: g'bye, Dick Rees on July 07, 2011, 06:36:32 pm
I notice that of the specs for dynamic mics (that I have looked at), there is no figure for SPL whereas condenser mic usually state this.  What is the reason?

Some do, some don't.  No matter what's listed, I still have to listen to them to validate any listed tolerances.  One mic in particular was rated max 145 dB, but started sounding "crunchy" much sooner. 

Best to rate them yourself under fire IMO.
Title: Re: No SPL figures for dynamic mics?
Post by: Dave Potter on July 08, 2011, 02:53:46 am
Ok.  I was just wondering if Dynamics distorted in a kinder way - Perhaps self compressing, or that the limits were much higher. 
Title: Re: No SPL figures for dynamic mics?
Post by: Chris Carpenter on July 08, 2011, 12:16:10 pm
Ok.  I was just wondering if Dynamics distorted in a kinder way - Perhaps self compressing, or that the limits were much higher.
The sound of a dynamic distorting sounds much better to me, sort of like analog vs digital distortion. However, unlike guitar amps, I don't like the sound of mics distorting at all. If it's too hot, I try to fix placement first, then swap with another mic (sm7).

The spec may not be as common because with no electronics to clip, the overload point is not so easily defined.  How much distortion is too much?
I think if standard mics gave us a THD value, people would be in shock. Haha.
Title: Re: No SPL figures for dynamic mics?
Post by: Brian Ehlers on July 08, 2011, 06:30:29 pm
Broad, sweeping generalization here, but I believe that the max SPL before significant distortion in dynamic mics is typically due to mechanical limitations, whereas in condensers it's typically due to limitations in headroom in the on-board electronics (and the phantom power).
Title: Re: No SPL figures for dynamic mics?
Post by: Geoff Doane on July 08, 2011, 09:39:41 pm
Broad, sweeping generalization here, but I believe that the max SPL before significant distortion in dynamic mics is typically due to mechanical limitations, whereas in condensers it's typically due to limitations in headroom in the on-board electronics (and the phantom power).

That was my feeling too.

Since my previous post, I checked the current AKG website, and most of the dynamics do have a maximum SPL spec, sometimes even with a distortion figure (1% and 3% levels).  They were all considerably better higher than their 1980s mics, which IIRC typically were only in the high 120 dB range.

Here's an example:

http://www.akg.com/site/products/powerslave,id,1060,pid,1060,nodeid,2,_language,EN,view,specs.html

GTD
Title: Re: No SPL figures for dynamic mics?
Post by: Chris Carpenter on July 09, 2011, 01:33:00 am
Broad, sweeping generalization here, but I believe that the max SPL before significant distortion in dynamic mics is typically due to mechanical limitations, whereas in condensers it's typically due to limitations in headroom in the on-board electronics (and the phantom power).

Oh, that's pretty cool... something new every day.
Title: Re: No SPL figures for dynamic mics?
Post by: George Dougherty on July 10, 2011, 06:10:27 pm
I notice that of the specs for dynamic mics (that I have looked at), there is no figure for SPL whereas condenser mic usually state this.  What is the reason?

A Sennheiser rep once told me all the Evolution series dynamic mics would easily handle 150db.  No distortion spec on that, but if that's the range where you get into any significant distortion on modern dynamic mics then I can see where it'd almost be a meaningless spec anymore unless a mic was particularly poor.
Title: Re: No SPL figures for dynamic mics?
Post by: Jeff Bankston on July 10, 2011, 07:13:29 pm
condensors(spell check) usually overload at a lower spl then dynamics.