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R/E/P => Klaus Heyne's Mic Lab => Topic started by: klaus on July 19, 2017, 04:56:48 pm

Title: Pop Filters: Which Work? Which Suck? The Lowdown
Post by: klaus on July 19, 2017, 04:56:48 pm
Here is my experience with pop screens and their physical, rather than emotional, effect on the vocal sound entering and exiting*:

First, I agree with Bob Ohlson's comments on another forum: if you can avoid a physical barrier between a vocalist and a sensitive condenser microphone, avoid it. Physics dictates that every barrier to an acoustic wave comes with audible side effects. But sometimes there is no choice and the sacrifice has to be made. How much of a detriment to either sound or pop protection?

Here are the choices and trade-offs:

Steadman-type corrugated single metal screen with holes
    Advantage: good transparency. Problems: spit protection is minimal, and (my main beef) the metal plate resonates and rings. Try to ping it with your knuckle and you will notice it. I found the distinct frequency of the resonance objectionable for recording fidelity: the resonance frequency will accentuate certain notes.

Hakan and similar open-cell foam screens
    Advantage: acceptable level of pop protection with minimal, but still audible high end and transient loss. Problem: comb-filtering with audible peaks. My speculation: as the holes in the foam are largely identical in diameter, resonances from standing waves are multiplied and amplified

Pauli and similar dense, double-layer nylon mesh screens
    Advantage: near optimal pop protection. Problem: audible muffling of highs and loss of transients, plus resonances in two areas, due to standing waves: the mesh layers are parallel, and the mounting ring, though perforated, has an endless number of parallel surfaces formed by the flat, hard frame. Its resonance frequency is determined by its diameter

Cheap double-layer nylon screens, home-made or bought
    Advantage: good transparency when the stocking material is not too dense; worse, same or   
    better pop protection as all the others, but at low cost. Problems: some comb filtering,
    depending on mesh weave and ring diameter, and audible loss of high frequencies   
    (see c.)

I have not included here any of the circular or semi-circular pop shields that mount on or next to the mic, like the famous Abbey Road in-house U48 contraptions, or Brauner’s handmade custom pop-cylinders. There are too many to list, but the same principles of physics apply as with any pop screen: a compromise ranging from good transparency to good pop-protection, but never both in one device.

For my work I keep coming back to a wooden, rather thin, 6” embroidery hoop / crochet ring bought for 99, covered with two layers of black pantyhose material (talk about emotional attachment!), and mounted on an old plastic mic mount. It’s quite transparent, and offers reasonable pop-protection at a ridiculously low price.

*I find it most helpful to test any screen directly with mouth-to-ear, rather than through listening via lossy recording and playback:
put your ear where a mic would be, as the vocalist speaks or sings into the screen. Ears are an astonishingly reliable test instrument!
Title: Re: Pop Filters: Which Work? Which Suck? The Lowdown
Post by: DanDan on December 12, 2019, 08:01:26 pm
I have been a tad obsessed with this over the years. I too have built some, with more layers.
I think any double layered design should have pressure escape holes in the hoop.
All this has become redundant for me since I adopted the Rycote one which attaches to their Universal Studio Mount.
DD
Title: Re: Pop Filters: Which Work? Which Suck? The Lowdown
Post by: klaus on December 12, 2019, 08:18:03 pm
Please upload a photo of the Rycote you mentioned. Always eager to expand horizons.
Title: Re: Pop Filters: Which Work? Which Suck? The Lowdown
Post by: DanDan on December 13, 2019, 10:59:17 am
Glad to. The whole device is plastic, no ringing. Soft rubber pads grip the mic. The foam is very open with varied size bubbles in it. Two discs supplied, washable.  Curved to deflect like those old Abbey Road ones. 
I suppose it is hardly surprising that Rycote would do a good pop and suspension, but I really cannot think of anything to improve on this design.
DD
(http://)
Title: Re: Pop Filters: Which Work? Which Suck? The Lowdown
Post by: Derek Reese Music on January 18, 2020, 11:56:27 am
Hello everyone, i am brand spanking new and a huge fan of Klaus, just wanted to say hello :-)

Ive recently been looking at the blast pad but its expensive.
I currently use a stedman proscreen xl pop filter.
I personally have not noticed a difference in sound, in terms of it changing the sound of my vocals.
Has anyone tried the blast pad ?

http://petesplaceaudio.com/blast-pad-mic-pop-screen
Title: Re: Pop Filters: Which Work? Which Suck? The Lowdown
Post by: klaus on January 18, 2020, 02:16:32 pm
Any metal pop filters-basically zigzagged sheets of sheet metal with holes drilled into them to let sound through, are insufficient spit protection for condenser mic capsules. Every time I see spit contamination on diaphragms, but the client insists that a pop screen was always used, it turned out to be one of these metal sheet filters.
Title: Re: Pop Filters: Which Work? Which Suck? The Lowdown
Post by: Derek Reese Music on January 18, 2020, 07:15:05 pm
This looks very interesting, i saw this being used in a vintage king video during a microphone shootout.
But it looks pretty thick ?
http://www.transaudiogroup.com/products/hakan/hakan-p110-pop-killer/
Title: Re: Pop Filters: Which Work? Which Suck? The Lowdown
Post by: klaus on January 18, 2020, 07:24:24 pm
Tested it and wanted to like it (the distributor is a good friend and was instrumental in launching the KHE mic).
But the foam has a flaw: comb filtering. How could this be? I scratched my head for days. Until I came up with the answer: many of the holes in the foam have exactly the same diameter and passage footprint. You multiply a specific acoustic obstacle by a thousand, you get a resonance frequency.

Why must we constantly try to reinvent the wheel, just to make a buck? Come up with a better compromise between transparency and spit protection a dual-layer stocking screen for $20 provides, and I will use it.
Title: Re: Pop Filters: Which Work? Which Suck? The Lowdown
Post by: Derek Reese Music on January 18, 2020, 07:26:38 pm
Hmmm, well i am now curious to try a dual layer stocking then :-)
The same could be said about playing an electric guitar, guitar, choice of strings, pick, cord and so on.
Each element contributes to the overall sound :-)
Do you mean a home made one or is there a particular dual layer you favor ?
Also Bob Olhsson's comment said-
"Make a popping sound with your mouth and move your hand around to find exactly where no blast of air can be felt."
THAT'S the place to put the mike and forget about pop screens!
But if i place the mic say slightly above the air blasts then i am getting more of a nasal sound from my nose, if i lower it then its in the throat area ?
either of those positions are not directly picking up your voice.
Title: Re: Pop Filters: Which Work? Which Suck? The Lowdown
Post by: klaus on January 19, 2020, 12:02:24 am
Home-made: Two-dollar embroidery hoop / crochet ring (https://www.michaels.com/loops-and-threads-wooden-embroidery-hoop/10124154.html) with free, from willing donor dual-layer pantyhose is just as good as the stuff you buy at Guitar Center.

Title: Re: Pop Filters: Which Work? Which Suck? The Lowdown
Post by: Jim Williams on January 19, 2020, 12:10:23 pm
My wife keeps me stocked with used pantyhose here. One way I found to evaluate these pooper stoppers is to put a pair right over your ears and listen to your best playback gear. Usually you will detect the filter effects that way.
Title: Re: Pop Filters: Which Work? Which Suck? The Lowdown
Post by: klaus on January 19, 2020, 03:38:33 pm
Brilliant. That's exactly how I evaluate pop filters as well, and a perfect method to detect comb and all other kinds of filtering, and the degree of opaqueness pop filters will introduce.
Funny how people don't believe in free or cheap. Especially when they don't trust their ears, they choose expensive ones, every time.
Title: Re: Pop Filters: Which Work? Which Suck? The Lowdown
Post by: RadarDoug2 on January 19, 2020, 03:47:25 pm
Come on Klaus, cheap Chinese mikes dont sound as good as expensive Neumanns! So sometimes expensive is best.
Title: Re: Pop Filters: Which Work? Which Suck? The Lowdown
Post by: klaus on January 19, 2020, 06:12:10 pm
Pop sceens!
Mics? Reverse psychology.
Title: Re: Pop Filters: Which Work? Which Suck? The Lowdown
Post by: ratite on January 21, 2020, 07:52:44 am
Klaus,I think you mean an embroidery hoop. https://en.wikipedia.org/wiki/Embroidery_hoop
Title: Re: Pop Filters: Which Work? Which Suck? The Lowdown
Post by: klaus on January 21, 2020, 01:27:23 pm
Semantic deviation duly noted, previous posts amended and example provided: https://www.michaels.com/loops-and-threads-wooden-embroidery-hoop/10124154.html
Title: Re: Pop Filters: Which Work? Which Suck? The Lowdown
Post by: Derek Reese Music on January 22, 2020, 03:32:27 am
This is great, now would you use two of these or put two layers of pantyhose?
What type of pantyhose sheer or opaque ?
And after stretching the hose around the ring how would you nearly fasten it ?
Title: Re: Pop Filters: Which Work? Which Suck? The Lowdown
Post by: klaus on January 22, 2020, 02:17:26 pm
It is of ultimate importance to only use black pantyhose material, due to its superior right-brain stimulative capacity*, while maintaining the same level of transparency and spit blocking other colors would provide.

The crochet ring/hoop/embroidery thing consists of an inner and outer hoop. The inner hoop claps whatever material is wrapped over it against the outer hoop. One layer of pantyhose wrapped over the inner ring ends up being two layers, once clamped in place.
Not rocket science by any means, just look at one of these and it will become apparent how it works.

*It can easily be proved that black nylon stocking material produces more platinum-selling records than all other colors combined!