Ribbon mic: ribbon material:readily available:substitutions?

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ToobieSnack

Well-known member
Joined
Mar 3, 2005
Messages
493
I've been a bit busy with this ribbon mic build. It looks nice but...
does any one have any suggested materials that are readily available to make ribbons for ribbon mics?
I have read abour sign makers metal leaf
and I am looking into some candy wrapping foil that might be thin enough?
what is my goal ? about 3 microns?
Also: curious about frequecy response and how ribbon length and width affect frequency response?
out of coincidence:
my lenght and width are almost exactly the same as my RCA 74b
RCA 2" x 1/8"
MINE 1 7/8" x 1/8"
AND actually because my ribbon mounting unit extends a tiny bit past the magnet structure the ribbon length might be 2" in mine also.

BTW: the only problem that I might have in my design concerns air flow/air pressure/sound wave flow to the back of the ribbon.

the RCA 74 has a lot of air space at the back of the ribbon

Mine has a column of air 3/16" x 1 7/8" x 1"
open at the back and the top of the magnet structure.( the bottom is the mount and therefore it's blocked and the front has the ribbon)

i have seen other design where the air flow was much tighter than my 74 so I am thinking I will be OK....we'll see

I'll post some pics in another post later. I think it will be a good looking mic when it's done.

anyway
looking forward to your responses.
thanks
ts
 
> materials that are readily available to make ribbons

Cigarette-pack foil, peeled off the paper.

> frequecy response and how ribbon length and width affect frequency response?

This is VERY complicated.

However, your main problem isn't frequency response, but output level. The ribbon mike is inefficient in a way that makes the frequency response fairly smooth; the tradeoff is very low output. So you fix the mid-band output level (it isn't easy) and discover that you have not changed the top-end output level (so it now droops). After that it gets very tricky.
 
Toobie,

Huh! Every ones in awhile all these questions come up without actual resolving. The reason is that there are actually no straight answers?they always depend on particular design. The seeming simplicity of the ribbons is more than offset by very complicated implementation.
Basically, any foil put between two poles of magnet will sound.... better, or worse, but it will. If you want to optimize your mic, the first, you have to decide which compromises you are willing to make. You cannot design a ribbon microphone without sacrifices. You can make it with excellent high-end response, but very low efficiency. On the other hand, if you are willing to give up high end, you can make actually high output ribbon, and so on. I could write here a whole essay on all these and other relationships, but it wouldn't bring you any closer to practical implementation, and will create even more confusion.

As for ribbon material. I never tried cigarette, chewing gum, burrito wrap, and all this kind of foils. If they are thin enough, they will work fine. I tried however, to unroll paper-in-oil caps. I took apart them all I could find in my junk boxes, local surplus, out of old equipment, and off ebay. I found a certain type of Illinois caps (with yellow PVC tubing around it), which had thinner foil (probably around 2.5um, IIRC). I would not use leaf, you have mentioned. It is way too thin (about 0.6um), and it's resistance is way too high. The transformer will load the ribbon, and the bass response won't be good, and also, noise will be way too high. To check it out, I spent months just to figure out how to handle this material and corrugate it so, that the foil will ?remember? and keep the shape consistently.
If you are serious about ribbons, I'd invest some money and get about 2um sheets from Goodfellow, Lebow, or other companies.

The RCA 74 is about 1/4" wide--I guess that what you meant. This size is determined by too many parameters, and as PRR has just said: "This is VERY complicated". It is impossible to make any certain advise here, without knowing foil thickness, magnet?s strength, transformer you use, tolerances you could handle, etc. To measure some of these things you will need some equipment--bridge, precision micrometer, precision scale, microscope, gaussmeter, etc. So, just stick to what you have on hands. I?d suggest to keep the ribbon 2? long, and then go from there. The shorter ribbons have lower resistance, have better directivity in vertical plane, but have lower sensitivity, and are prone to resonance modes, and trust me, at least at this point, you don't want to get into fighting this.

>BTW: the only problem that I might have in my design concerns air flow/air pressure/sound wave flow to the back of the ribbon.

Well, it is a fundamental problem of ANY ribbon mic, and ultimately, is one of the most important sources of compromises.

But enough confusion.
The best would be if you post pics, and then we could go from there.
 
thanks PRR and Mairik

If you are serious about ribbons, I'd invest some money and get about 2um sheets from Goodfellow, Lebow, or other companies

i will search for these companies on google when I am done responding and preparing my pics for posting (working) etc

If anyone can post a website for these fellows that would be great.

BTW: ok I re-measured my RCA 74b and indeed it is 1/8 " wide....maybe this was a mod but this one sounds good ...even with my ribbon sagging.


The ribbon mike is inefficient in a way that makes the frequency response fairly smooth; the tradeoff is very low output. So you fix the mid-band output level (it isn't easy) and discover that you have not changed the top-end output level (so it now droops). After that it gets very tricky.

the way I use my ribbon in a double mic scheme because of the inefficiecy in the high end. I use the ribbon for lows and mids and the condenser for high end. The combination is very nice. I have even thought of trying to combine both elements but I think the magnets wouold interfere with the proper operation of the condenser. so I will stick with 2 mics for now.

I am making this mic with an 8 way adjustable ribbon (up, down,left ,right,forward backward, twist left , twist right) assuming that this would be helpful in optimizing the mic.(and making it easier to install a ribbon)

Is ribbon tension where all these adjustments for the frequency response will be made?

I know the trafo used will be a factor. I will use sowter trafos in the end
I am considering the 40:1 mu metal trafo for ribbon mics they have on their website.(there is only one with mu metal case)
to start with I will use the trafo frm my 74b since I plan on replacing it anyway with a sowter. ( this mic is very noisy at the high end so I just shelf it on the highs....which is a pain but....with the condenser it works nicely)

To check it out, I spent months just to figure out how to handle this material and corrugate it so, that the foil will ?remember? and keep the shape consistently.

I have read that for the corrugation:
I would run the ribbon material trough two gears/cogs for perforation.
My RCA has a measurement of approx 1/8 " from peak to peak on the ribbon. I will try to get some gears to match this as closely as possible.

are there some trick I should know to "treat the ribbon so that it will maintain it's shape?

I would be very interested in this. If necessary PM me.

OK gotta go to work to pay the bills.....waaaahhh.....I will hav to post pics later.

thanks
ts
 
[quote author="ToobieSnack"]

BTW: ok I re-measured my RCA 74b and indeed it is 1/8 " wide....maybe this was a mod but this one sounds good ...even with my ribbon sagging.
[/quote]

Does it look like this?:

74bribn.jpg
 
marik,

yep that is what mine looks like
and I triple check the measurement.
I'll post a pic of my RCA too.
but I'll post pics of my mic first.( I have them on my computer now)
I need a few minuits to reduce their size/compress/post.

I have not had a chance to search for the ribbon material provider you suggested.
If your could post the link it would save me some time and trouble and ...
that would be nice....
anyway I am starting this pic preperation process now
be right back
thanks
ts
 
hey here are some pics of what I have

http://www.groupdiy.com/index.php?topic=6973

ts builds a ribbon mic...
all help appreciated
thanks
ts
 
marik thanks for the lead on Lebow. that material is fairly reasonable in price .... and in the US.

my main reason for wanting the sub is to practice the installation of the ribbon and just to test the rest of the mic before final ribbon placement.

I guess there is a good possibility that it would sound good but....

I can barely remeber that, as a kid, we used to seperate the foil from a gum wrapper I just can't remember how we did it. there was some kind of little trick... I think maybe pressing hard with the back of your fingernail which I guess would stretch t foil just a bit or or .....OH hell.... I can't remember
i do know there is an easier less tedious way to seperate the paper from the foil.
If anyone can remind me that would be great.

also thanks for the oil cap suggestion. I would have missed that one.

any way
have fun
thanks all
ts
 
hey peeps
I found this link in a mic meta here which led me to a recently posted link at one of the reccomended websites
this seems to be THE most affordable route to go
***25***leafs 5.5" x 5.5"
for 7 bucks US
woah
http://www.dickblick.com/zz270/12a/

thanks marik for suggestion the meta I never made it far enough through the meta meta to see the ribbon mic stuff before. A lot of stuff is buried deep and searching can be very benificial.
BTW I also JUST realized sthe search engine here uses the AND OR NOT structure rather than + - "" and ().

hope this helps
ts
 
[quote author="ToobieSnack"]hey peeps
I found this link in a mic meta here which led me to a recently posted link at one of the reccomended websites
this seems to be THE most affordable route to go
***25***leafs 5.5" x 5.5"
for 7 bucks US
woah
http://www.dickblick.com/zz270/12a/
[/quote]Unfortunately, this is that submicron leaf that is next to impossible to work with. You can also get it at local craft supply stores such as Michaels or JoAnns
 
thanks crazydoc

the artical went on and on about the 2 micron req and just after that this link was posted
i assumed this was a link to some 2 micron material.
I'm glad you said something before i (or anyone else) went out and got some and soon thereafter become pissed off....lol
I went to Michaels but the only leaf I found seems to be adhered to a plastic film (or some other material)
maybe I was looking in the wrong section.
I guess my (our) search continuesI'll keep lookinn
we can try hared enough for long enough and we wil succeed ... I hope soon,
thanks
ts
 
here's an interesting quote i found whole searching:

Dear Sir/Madam;

As Onurpak Ambalaj is a producer of aluminium cigarette foil for tobacco packets
we laminate white sulphite paper (30-70 gsm) with 6,35 / 6,5 / 7,0 / 8,0 micron
aluminium foil.

Width:1050 or (930 mm. changeble tolerance)
ID: 150 mm.
OD: 700 mm. max.
Alloy: 98 % min.
Bright side is wounded outside.
Core protrusion= 5-10 cm. for each side. / max. approx. 1400 mm. core lenght. /
There has to be pinhole 10x10 mm. at least on one side.

Could you please send us your quotation for 750 tons. There will be addition
near to the end of the year.

ts
 
hey update:
i went to my sisters last night ans she had ciggaretts witht the smoothe shiny foil finish. I got some of this and brought it home.

just for a test i cut a strip ,,
wet the back with water
and gently rubbed the paperbacking off the foil
DAMN! turned out nice and wasn't hard at all
the foil would stick to the surface of the table and had to be gently lifted
but after that i had some nice ribbon material.
i messed around a little with it putting different corrugations from lids of differesdnt things around the kitchen,
a soy sauce lid worked pretty good because of the deep ridges in the cap. i will look for somethng with some larger indentions.
I have seen DIY ribbons with tight smalll ridges:
Question: anyone used a ribbon with these tiny indentions:
how did it work ?
does this pattern matter much?
anyway off to experiment more
later
ts
 
Question: anyone used a ribbon with these tiny indentions:
how did it work ?
does this pattern matter much?
anyway off to experiment more
later
ts

I did two reribbons with the submicron stuff, with tighter corrugations. One of them sounded very cool when I was done, much improved response both high & low. The other one sounded pretty much like the original ribbon. Of course there are a few variables involved; but while the difference isn't visible, it sure is audible.

I would just do the best corrugations you can, install the ribbon, and see how it sounds. Doesn't cost anything to keep trying.
 
hey thanks for your reply,
i just finished up some epoxy work and a ribbon.
i used the small indentions as it was all I have at the time.
i have a nice tension adjustment on this mic so getting this tiny pattern just tight enough may be possible.
if you could elaborate on this difference you speak of that would be nice.
thanks
ts
 
hey people,

just wanted to add some info/updates on my ribbon progress

I made a ribbon yesterday from the cig foil.
i cut my ribbons before I remove the paper backing.
it is much easier to cut with the paper still on it.
( i can't imagine doing it any other way...working withthe pure foil must be a royal pain.)
after cutting I lay it face down with the paper side facing up.
I dip my finger in the water (alcohol would probably be a better choice)
holding the ribbon down with one hand (finger) i use the other hand to ruboff the paper.
KEEP THE RIBBON STRAIGHT DON'T LET IT WRINKLE.

start at the end farthest from your left hand and work your way closer and closer until you have a fairly clean ribbon.
KEEP ADDING WATER AS NECESSARY.
the water will let the ribbon "float" a little and you can pull it through the water to straighten it when needed.

I leave a little bit of paper on the ribbon so it handles easier (just on the end ...whatever is left under my finger)

OK now we have a fairly clean ribbon ....wet..... and ready to recieve a pattern.

KEEP IT WET.

WET YOUR RECIEVING UNIT (what ever you have chosen for your mold)
I used (with great success I might add) the chuck on my cordless drill.
It had some nice evenly spaced, wide and high "bumps"

lay your ribbon on this after both the ribbon and the unit are wet
KEEP IT STRAIGHT
I aligned it wthe the edge of the chuck.

OK now we have a wet ribbon on a wet die (form)
and now we are ready to impart the pattern from my form to the material

THIS IS THE HARD PART

Ok..... using my thumb and pressing firmly worked for tiny patterns ...BUT...
not for the larger ones
the ribbon will rip. or it stick to your thumb and raises up/tears

for the larger ones I went "ridge to ridge" tucking the foil into the recesses with the back of a "hook blade razor" (or a guitar pick)
each time you tuck one fold ... you have to advance your other hand and hold that fold in place .... before attempting to continue to the next.

HOLD ...TUCK....ADVANCE once for each indention

takes patience, a delicate touch and a steady hand

I'll be installing it into my ribbon mic project tonight (or in th morning...just remembered some epoxy work i need first)

I'll post some pics

anyway I hope this helps.
ts
ALSO BTW: i think the cheap cig pack are cheap for a reason... their cheaper because they use cheaper (thinner ) raw materials.
Therefore i think these ribbons are very close...
the rubbing may even stretch and thin a bit..

PS look for a pic update on my ribbon mic coming soon.
 
hey
here's a link to capicitor foil thanks to a forum friend..thanks cosmo

http://www.capacitorindustries.com/materials.htm

later
ts
 
Toobie, the way I do the corrugation is to grab one of those bottle caps (silver cleaner bottle in my case, but use whatever might seem to do the trick), and carefully wrap the ribbon around it a little bit on the loose side to prevent it from ripping. Then, I roll a strip cut from a piece of high density foam I had lying around over it. That's it!

I am not sure whether having deeper corrugations changes the sound quality at all, but it would be interesting to experiment/hear the opinion of anyone who's done it.

I think the main concern is perhaps the ribbon thickness and width?
 
OK check this out.... :grin:

in a recently discovered text here at the forum...

http://www.groupdiy.com/index.php?topic=2427

the method for making the ribbon pattern (impressions) is:...yur gonna love this......something as readily available and stupid simple.......

a hair comb.....:shock: :shock: :grin:

it's obvious now huh? :grin:

lay your ribbon on the comb and press with foam...hmmm poetry... :grin:

OK on another note...kind of a challenge for us all
the cigarette and KitKat foil (etc) we are using is so wonderful... maybe a tiny bit too thick...so..
what if:

i used a stainless steel roller from a vcr on a track with a stainless steel "flat" base and a weigt attached to the top of the roller and hey...maybe a fish pump too...no kidding..

I could:

attach my ribbon to the base...start the motorized weighted roller...and use the vibration of the fish pump for a semi hammering effect....

I would roll the ribbon to the point of failure...counting the roller passes...and reduce this number 80% from the failure rate..

sound cool?

do you think the use of some mineral oil or??? would be a good idea?

something to consider.. :grin:

later ts
 
A haircomb! That's genius, Toobie! I'm even thinking of two haircombs, pressed against each other... I must experiment!

Anyway, you know, talking about ribbon material, I find that if you rub the paper out of the cigarette foil with your finger and water/alcohol and then keep rubbing, you'll notice that the ribbon actually stretches. Which means that it gets thinner too, right?

There's a thing I have learned from experimenting (and here I retract a recent impression): to get a better HF response, it seems that the key is a thin ribbon (I am talking thinckness, not width: keep that at 5 mm) with deep corrugations seems ot do the trick. I knew corrugations were important, but until today thought that as long as there is some degree of corrugation, it wouldn't be critical.

I found that a combination of thin ribbon material and deep corrugations is all it takes to achieve good HF response, provided that the magnetic field is as it should be.

I can confirm that cigarette foil stretched with the finger (try this before your build steel roller-fish pump contraption from hell - who knows, might work just as well and it's a hell of a lot simpler...) is just about as thin as you can comfortably work with. OK, maybe just a tiiiiiiiiiiiiiiny bit thinner...
 

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