Foam-ing at the mouth . . .

[GeorgeToledo]

I got a chance to look up one of the other currently available products I have here for refurbs:

https://www.markertek.com/product/w...-12in-x-1-4-inch-thick-black-wind-screen-foam

 

[GeorgeToledo]

One thing that is easy to work with when you want more of a silk/cloth look, is to use polyester mosquito netting. Usually available in a variety of colors on ebay.

Silk mosquito netting can be appropriate as well I guess, but pricier. I never particularly love the fiber shed I see as silks for some mics age.

 

[gyraf]

What about perhaps metal foam - Metal foam - Wikipedia - it seems quite usable for the purpose if formed right. Isn't it Josephson that has a mic with metal-foam grille?

/Jakob E.

 

[abbey road d enfer]

What about perhaps metal foam - Metal foam - Wikipedia - it seems quite usable for the purpose if formed right. Isn't it Josephson that has a mic with metal-foam grille?

/Jakob E.

IINM it's what AKG used on the D202/222.

 

[gyraf]

..wasn't the AKG's just sintered metal?

 

[abbey road d enfer]

..wasn't the AKG's just sintered metal?

AFAIK, sintering is the process for producing metal foam...?

 

[Khron]

I thought (some) Aston mics used some metal-wool type thing inside the headbaskets, but i could be wrong.

 

[mad.ax]

Regarding fabric, I recently helped a friend to restore a Melodium 42B. Visited a few fabric shops, and it appears that the best fabric is called: organdy. It's used for clothes but also for windows see thru drapes. Bought a pair of such drapes for about €4 and there's enough material for dozens of microphones!
The trick is to glue it properly without letting the glue clog the fabric. I found that spray glue works well.

Axel

 

[MicMaven]

, a wide mesh light silk scarf might be the best job if you want to get it looking close the original .

Your comment strikes a pleasant chord. I may acquire a bright red silk or double knit fabric, and apply it with an appropriate spray contact cement on the inside of the shell, carefully laying and stretching it in place, replicating the original.

Hmmm ... maybe ... ZZzzzz.... (He typed, slipping into a deep, contemplative snooze, daydreaming visions of audio glammour ...) // James

 

[Gavin Pursinger]

I have an ' old 55' from a horse racing track...I use it as the studio talkback mic. What else would you suggest to us it for ?
It looks so very cool and seems to have a pretty wide pattern. It's good to try stuff of an old school nature !!!

 

[Tubetec]

Silk is a very resiliant fabric , 70 years of dried spittle caked in .its bound to fall appart and make a mess ,
A plastic type fabric might melt a bit when you glue it to the frame .

I have one of the Elvis era models and one of the later ones , they sound reasonably well matched , I think the capsule in the Elvis era mic I transplanted from the more modern 55SH . Im not sure how the capsule differed from early to late models . maybe you can post a pic of the original capsule Mic?

I wish now I had kept my third mic body , not sure where it went in the end , I think I have a broken capsule around someplace also , maybe theres such a thing as a recone kit for it Im not sure .

Its more of an EQ effect mic , thats how I tend to use it , used backed off in the room on drums they make a great ambience mic , on guitar cabs it might tend to sound screechy but you always have the tone on the amp to scoop out the mids a bit , voice ,if you want a contrast to the usual condenser mic'd vocal its great , if your looking for a slightly more aggressive rock sound of any kind ,it just works , minor EQ'ing and your ready to hit record .
Hi-z mode might be useful if you want an even more Lo-Fi sound and you can add extra dirt with stomp boxes or take the output directly to a tube guitar amp .
If I had another donor 55 body Id figure out a way of mounting up an Sm-7 capsule in it , its the natural upgrade , now you have a top of the range dynamic mic for studio or stage with all the vibeyness added .

 

[MicMaven]

Good Morning, Mr. Tubetec. See attached photos of original guts in my Unidyne 55C before "restoration." These are low-res images. Lemme know if you need higher res.

Happy trails to you. // James

 

[MicMaven]

Good Day! FOLLOW UP to my earlier inquiry:

I recently purchased a 15" x 24" x 3/16" (.019") sheet of Polyurethane foam from Lowes hardware store for $3.99. It is billed as a washable air conditioner filter. It should accommodate several projects. I would prefer slightly thicker, more dense foam (i.e., more holes per inch.) Nevertheless, I believe this will work well enough for a fairly low cost. You can buy it on eBay.com for around the same cost, plus around $4-$5 shipping which more than doubles the cost, yet may be a sensible option for those who do not live close to a Lowes or similar big box hardware store. (It seems to be a seasonal item, so it may be harder to find this time of year...)

I appreciate all the ideas and input on this, especially the discussion on retrofitting old Shure Unidyne 55 shells with various fabric liners. I am still looking for a suitable red silk or double knit fabric to glue in my example.

Happy trails to all. James - K8JHR -

 

[GeorgeToledo]

That foam can work ok, but the foams I linked are much better and more appropriate, and results *sound better* in my opinion.

Also, you are looking for less dense foam if you’re looking for more holes, not denser.

 

[MicMaven]

Good morning GT. Apparently I can only fool some of the people ... usually myself, anyway!

Hmmm... Are you sure about that hole-size-density thing? When I purchased similar foam sponges for my business, I believe more holes per inch meant smaller holes and, concomitantly, more material per inch. I believe it is the size of the hole that counts. N'est ce pas? (I cannot imagine why it would be in reverse because it comes in a sheet opposed to sponge - but maybe I am corn-fused.)

As for sounding better ... Sheesh! I hope it does not make any noise at all!

But seriously, folks ... I am confident this foam is acoustically transparent and is good enough to protect my capsules from ... um ... well, you know ... eee-yuck. If my stuff is less dense than what Markertek sells for nearly three times more money (plus shipping) it should be even more transparent.

I sorta think you are over-thinking the problem. The customer specified a very low cost solution. I am not running a recording studio and ham radio ops are notoriously cheap, so $4 is way more attractive than $11.25 plus shipping (notwithstanding Markertek is a treat to deal with.)

Thanks for sharing your take! (Hope this comes off in good humor) Happy trails, Old Man. James - K8JHR -

 

[GeorgeToledo]

What about perhaps metal foam - Metal foam - Wikipedia - it seems quite usable for the purpose if formed right. Isn't it Josephson that has a mic with metal-foam grille?

/Jakob E.

Josephson’s head grill appears to be made of porous aluminum as opposed to sintered metal.

http://www.porous-aluminum.com/sinteredmetal.html

 

[Tubetec]

Hi Mic,
Thats definately a different capsule to the later smaller Shure skull mics ,

I sometimes like to imagine how many great nights these old mics were responsible for in the dancehalls and céilí sessions back in the olden days .
I once got a 50W Marshall, two Park column speaker cabinets and a pair of reslo ribbon mics from an old Accordion player from the show band days here in Ireland , his sound must have been unbelieveable with a little extra distorted edge from the stack sitting right behind him . Dual figure 8's meant good feedback rejection too I'll bet .

 

[MicMaven]

Good story about that old gear and the guy who used it. - James

 

[JohnRoberts]

AFAIK, sintering is the process for producing metal foam...?

Sintering is a manufacturing process where dissimilar metals are combined while in powder form using paraffin or similar binder. This powdered media is pressed into a mold to form different shapes. These molded shapes are then cooked in an oven to melt the lower temperature metal until they flow together into a single piece of metal.

Back in the 60's I had a coop job working in a sintering factory in NJ. One high volume part we made was heavy metal counterweights used to balance helicopter rotors. IIRC the two metals combined in that part were tungsten and maybe copper (?).

JR

 

[MicMaven]

Good Day Microphone Mavens. This is a followup to our previous discussion regarding acoustically transparent foam and also restoring my old Shure Unidyne 55C.

I fitted my reformed Unidyne 55C with a sheet of thin air conditioner foam discussed in this thread, and covered that with with a bit of crimson fabric ... and VOILA ! I did not glue it to the inside of the shell - it is simply held in place by the foam which is easy to use and is acoustically transparent. My wife and I think it this a substantial improvement. What do YOU think?

Happy trails to all. James - K8JHR -