CoolCat
Well-known member
2019... revisit and enjoy a SM81 mic review with a PG81 of interest too.
SM81, the internet search trivia rabbit hole
1) SM81 was designed by Ernie Seeler...he also designed the SM57. Bill Bevan did the electronics.
2) 1978 release (40yrs and going)
3) Went through some changes. Will try to summarize this a little as I find it interesting.
4) was USA then the Mexico plant of today 7/17/2019...
2013- article
Everything Audio Network: Retro Recording Review!A Classic Benchmark in Microphone Accuracy:The Shure SM81 Small-Diaphragm Condenser
Which one to buy?
USA has the flat name plate on it, but going old can also mean electret is old...is that a good thing?
* Electret mics
Newer has better noise floor per spec.
Whats noise floor? per Neumann
<10db best and impressive
11-15db- very good
16-19- good
20-23 -pretty noisy
24 and above- get another mic
PG81 is 20db per Recording Hacks and SM81 is 16db or better for the newer SM81's. ..to 19db using some white noise spec to test weighted per DIN 45 405
both are probably far better than my room noise spec.
Electret? some old posts mention they get weaker over time?
SOS article clip-
The quality breakthrough came when the electret material was fixed to the backplate (hence the term back-electret), allowing it to be used in conjunction with a conventional gold-on-Mylar diaphragm, providing designers with the means to achieve the same performance as from a conventional capacitor mic but without the need for an external polarising voltage to maintain the charge. This allows some live back-electret mics to be powered from batteries when phantom power isn't available, as only the preamplifier needs power and this can often be run at a much lower voltage than a typical capsule's polarising voltage.
A good back-electret mic can perform every bit as well as a traditional capacitor design, and in some cases a little better, though the electrical charge sealed in the electret material can leak away very slowly over a period of several decades, resulting in a slight decrease in sensitivity[/U]. In reality, though, this leakage is generally so small as not to be a practical issue.
US or Not?
SM81 seems the simplest way to determine USA made is the flat label on it. However not 100% sure what and when the label disappeared and the body is round and champagne color became the standard. Im curious though.
I asked Shure "whats going on with some saying the SM81 changed a lot?"
Reply:
There is no "new" version of the SM81. Nothing has been changed aside from some cosmetics and location of manufacturing over the years. The same machines and designs are used for this mic.
Applications Engineer | Shure, Inc.
Ohmmmmmmm….
SM81 Impedance 150ohm
PG81 600 ohm
SM81 LC …LC means less cable...SM means Studio Microphone...
PG81...PG means Performance Gear
Both made of steel.
New $
$349 SM81
$139 PG81
Used SM81 $200 - $300
Used PG81 $50-$60
2008 Home Recording Question?
https://homerecording.com/bbs/equipment-forums/microphones/sm81-vs-pg81-269722/
SM81, the internet search trivia rabbit hole
1) SM81 was designed by Ernie Seeler...he also designed the SM57. Bill Bevan did the electronics.
2) 1978 release (40yrs and going)
3) Went through some changes. Will try to summarize this a little as I find it interesting.
4) was USA then the Mexico plant of today 7/17/2019...
2013- article
Everything Audio Network: Retro Recording Review!A Classic Benchmark in Microphone Accuracy:The Shure SM81 Small-Diaphragm Condenser
Which one to buy?
USA has the flat name plate on it, but going old can also mean electret is old...is that a good thing?
* Electret mics
Newer has better noise floor per spec.
Whats noise floor? per Neumann
<10db best and impressive
11-15db- very good
16-19- good
20-23 -pretty noisy
24 and above- get another mic
PG81 is 20db per Recording Hacks and SM81 is 16db or better for the newer SM81's. ..to 19db using some white noise spec to test weighted per DIN 45 405
both are probably far better than my room noise spec.
Electret? some old posts mention they get weaker over time?
SOS article clip-
The quality breakthrough came when the electret material was fixed to the backplate (hence the term back-electret), allowing it to be used in conjunction with a conventional gold-on-Mylar diaphragm, providing designers with the means to achieve the same performance as from a conventional capacitor mic but without the need for an external polarising voltage to maintain the charge. This allows some live back-electret mics to be powered from batteries when phantom power isn't available, as only the preamplifier needs power and this can often be run at a much lower voltage than a typical capsule's polarising voltage.
A good back-electret mic can perform every bit as well as a traditional capacitor design, and in some cases a little better, though the electrical charge sealed in the electret material can leak away very slowly over a period of several decades, resulting in a slight decrease in sensitivity[/U]. In reality, though, this leakage is generally so small as not to be a practical issue.
US or Not?
SM81 seems the simplest way to determine USA made is the flat label on it. However not 100% sure what and when the label disappeared and the body is round and champagne color became the standard. Im curious though.
I asked Shure "whats going on with some saying the SM81 changed a lot?"
Reply:
There is no "new" version of the SM81. Nothing has been changed aside from some cosmetics and location of manufacturing over the years. The same machines and designs are used for this mic.
Applications Engineer | Shure, Inc.
Ohmmmmmmm….
SM81 Impedance 150ohm
PG81 600 ohm
SM81 LC …LC means less cable...SM means Studio Microphone...
PG81...PG means Performance Gear
Both made of steel.
New $
$349 SM81
$139 PG81
Used SM81 $200 - $300
Used PG81 $50-$60
2008 Home Recording Question?
https://homerecording.com/bbs/equipment-forums/microphones/sm81-vs-pg81-269722/