Shure SM81 and a PG81

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. :rolleyes:

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….:yawn:
SM81 Impedance 150ohm
PG81 600 ohm


SM81 LC …LC means less cable...SM means Studio Microphone... :rolleyes:
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? :D
https://homerecording.com/bbs/equipment-forums/microphones/sm81-vs-pg81-269722/
 

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this should be interesting.... got a new SM81 and some original SM81's (pair) and the pair of PG81's

anyone have the SM81 stories or memorys of this mic, going forward or back?

1978.... 1988..... 1998.... 2008.....2018....


add>>> down the rabbit hole of acoustics and SM81 and all the rest. So many articles mention SM81 as some staple mic for pro's and yes, I see Capitol Records has them and Abbey Road...along with Shure SM57's....but for the life of my surfing on this topic I cant find any Engineers listing big records with SM81's....maybe it was before the internet the mic became what it is?

I see a lot of KM 84 and DPA? and Earthworks.... and most beautiful room studios have the SDC and a big LDC capturing the sound...

oh well...my original point was noisy room acoustic mic and PG81 Pair for $100...and now a Pair of SM81 USA early $350 and a single new SM81 for $230....I used to have a MXL 991 around here somewhere but lost it.

I wonder why did the SM81 become a studio mic? When did SDC mics become needed?

from BlinD Wille playing blues to RCA ribbons and Neumann U47....then somehow SDC became something... Neumann seemed to have another leader product with the KM 84....transformer, but the KM 184 is brighter with no transformer and it wasnt as raved about...why wouldnt they put the transformer back in it? after all the less comparison reviews?...
I dont have cash to play that poker table with Neumann....Shure SM81...and SM57 and SM7 , KSM27,32,44...is ok. I like that, great stuff and built like tanks in case the Bass Guitar head whacks it...Shure mics seem to be able to take some hits.

Tweaksheadz gave the SM81 a Pick Award, I always liked his reviews and site. time for a coffee..
 
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Review end... playing these three, as singles on the acoustic, in the noisy room....

1) all did well at cancelling the room noise, to some extent, with attention to the mic position.
2) all three expect the player sit fairly still or the pattern drops off quickly
3) Pre Z of 500 or 2K has a big influence , the latter really gets the condenser sound while the 500 is flat, less sizzlepolish.

the PG81 $50 used, with some eq I probably couldnt tell a difference in mix.

the new 81 vs vintage 81's were harder to tell apart. actually I couldn't really tell them apart... capsules might be slight newer or older I dont have that kind of ear to hear miniscule difference. Some say they added top end to the newer 81's , I dont know.
I got a great deal on the old ones $175 each with the wierd cap (ill never use) and the champagne mic holder (ill never use).
The new 81 was $239 and has the case and foam and black clip. ..but Im not going anywhere.


One of the vintage US 81 had a crackling, sound I thought..alright! ripped off!
Took it apart and its some weird socket XLR so I cleaned it up and problem fixed (also found some chat/posts about some XLr issues on these...internet is great for repairs.) These days I enjoy tinkering tech stuff as much as playing.

now I have 5 qty 81's and only need 1qty ...:guitar:

I see below a 2008 HR PG81 vs SM81...
ADD> 4days later and playbacks and reference tracks of Blackbird/McCartney-White Album.... due to subtle mic movement making such a sound change on close micing I don't see a need of any of the comparison. PG81 does great, the new SM81 and vintage SM81 don't need my review, but the Shure quality is there in all of them. The vintage one has no sign of the electret being quieter imo, the huge difference is mic positioning..so the PG81 does offer battery operation if that's something...this gear test drive shows "move the mic position" is the big tone dog. $50 each PG81 used, the Vintage US made SM81 is a great deal I could possibly sell one and get this one for free...which is what I'll probably do...the new version return to the Used section of GC with a loss of shipping $$.
 

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