开云体育

Larger hole == higher resonance; smaller hole == lower resonance
frequency.
Diffraction effects might have more influence on HF performance -- dunno.

Keith Nelsen wrote:
Think PZM (Pressure Zone Microphone) which eliminates sound from
other axis. Works great.

But if I recall correctly, making of PZM microphones has some
patent issues.

Indrek

One problem, IMHO, with the panasonics is the size of the hole in the
front. It is too small and can reverberate under extremely loud sound
pressure levels.

If you can make something with a larger diameter hole it would be great.

Bob Cain wrote:

Someone here, I think perhaps it was Seigfried back when he
was a contributer, calculated the resonance of the Helmholtz
resonater that the cavity and hole comprise and found it to
be well above the audio band. Enlarging the hole could even
possibly lower it.

This is true for audio that is sourced perpendicular to the
diaphragm in the capsule. The problem is reflected sound that
enters from an off axes point. That sound would setup the
comb effect due to the difference in time that the sound
reached the individual capsule diaphragms.

One problem, IMHO, with the panasonics is the size of the hole in the
front. It is too small and can reverberate under extremely loud sound
pressure levels.

If you can make something with a larger diameter hole it would be great.

Everyone has good points

3 pad with FET sounds popular

I'm also finding out that with FET's when I go to a 9.7mm capsule there is =

room
to use an FET tthat gets me 65 insttead of tthe typical 58 from the fet tha=

t fits
6mm

So I'm thinkinng why not take the bigger fet and tack it onto the back of a=

6mm
instead of inside where it wont fit,

or is the 3 wire linkwitz mod getting us there
anyway ???

What exactly is the linkwitz mod doing?

What exactly is the linkwitz mod doing?

3 pad w/ best FET available? Any preferences on FET #? Sanyo 202 OK? NEC 1109-J34 or J36? Anything else?

Actually as capsules are made of quite thin aluminum, you can
easily cut hole larger with sharp scalpel (which will not be
so sharp after performing this mod).

Have you done that? There's not a lot of clearance between the
face and the diaphragm.

The comb filter effect would kill anything that would sound liek music!!

cornelius de Kam wrote:

HI gang...
Several people have written that they would appreciate something about

1/2

in diam.
The old engineering thing in me asks, what would happen if you took 4
capsules and
wrapped them together (faced the same way) all wired in paralell and then
into just
one FET as a follower... MMMMM I'm listening, so burn my ears off.
Connie

From: "Bob Andres" <robert.andres@...>
Reply-To: micbuilders@...
To: <micbuilders@...>
Subject: Re: [micbuilders] Re: WM-60/61 Final Input Please - cost
Date: Mon, 8 Dec 2003 23:06:56 -0500

Sounds great. You can plan on getting an order from me!

----- Original Message -----
From: "mstrong82" <mstrong@...>
To: <micbuilders@...>
Sent: Monday, December 08, 2003 7:58 PM
Subject: [micbuilders] Re: WM-60/61 Final Input Please - cost

should be around digi small quan 61 prices

--- In micbuilders@..., Bob Andres <robert.andres@c...>
wrote:

This all sounds great. Any idea what these things will cost?



on 12/8/03 3:20 PM, mstrong82 at mstrong@j... wrote:

No, I haven't eliminated anything as far as directional or size.

Someone

was

interested in better 55's, others in 1/2", etc. All are

interesting.

I must focus on getting one thing at a time done, or nothing will

happen.

Just
made some 60 equals, but people are saying that 61 is much

preferred.

I think 3 pads, and the best FET that will fit.

I am hearing no FET and fooling with a 6mm RF mic won't help noise,

but

will

help LF, which seems flat anyway... so no non FET version

The remaining question I am aware of is the hole size, normal,

bigger
or

none. I am hearing people that have experimented with making the

hole

bigger, who have actually tested the results find no improvement and

in

fact

degradation of the low end. One guy was saying the cavity resonates

at

extremely high SPL's, (over 120?) That's not a problem for me,

anyone

else?

ALSO, part of the purpose of the hole and the metal around it is to

protect

the
membrane, which DOES need protection.

I WANT FINAL INPUT AND THOUGHTS, PLEASE

61 better starting point than 60?

3 pad w/ best FET available? Any preferences on FET #? Sanyo 202

OK?

NEC 1109-J34 or J36? Anything else?

Bigger omni next, but first let's finish this one. I can fit a

2SK118
in a

9.7mm
and should be able to tweak 65 S/N out of it, without too much

sweat.
We

shall see.



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I have been following the thread on the 60/61 replacement. Here is my 2 =

cents worth.

* Should have flat output like the 61 (20 to 20k ±3 db or better
would be good)
* Should be the 6 mm size for faster transit response
* Would prefer 2 wire output without FEET or opamp (User to provide
own amp depending on application)
* If FET is included, should have 3 pads for access to both source
and drain connection
* LOW noise a must
* Omni for first run - others to follow

Just some thoughts.
Keith

mstrong82 wrote:

LOL... NO preorders don't help. I'll make some, seed a bunch to
those who added
their input and if they get the seal of approval, then I'll stock
some, THEN I will accept
paid orders, not before.

THEN we can move on to figuring out what the next item should be and
making it.



--- In micbuilders@..., "umashankar mantravadi"
<umashanks@h...>
wrote:

i would like to see it in two sizes one as small as possible, and

the other

about 1/2 diameter.The small one as omni, and the larger one both

omni and

cardioid.

i would like to see, instead of a the tiny hole on all panasonic

capsules, a

diaphraghm fully open , protected by a wire mesh, if necessary.

No fet and fet (if very good are both ok. i think the small capsule

must

have an fet. both should have three pads, so linkwitz are any other

future

system can be implemented without cutting traces. if the pads are to =

joined, they can always be joined up at the other end of cable, if

only one

uses two conductor plus shield capbling.

is that a very big wish list?

i will preorder if that will help. ( i live in india, but these days =

i can

use my credit card to buy abroad(.

umashankar

We are putting our heads together to make a replacement for the

WM-61 that

is Linkwitz Mod ready, items to be nailed down are FET selection,

hole size

vs
no hole, etc.

I would like everyone's final input on the design so we do don't

have to do

it
over again.

It is being finalized over on micbuilders (the new group) If you

have any

input
on this, please post it over there as we just about ready to make

these and

anyone with input get's some to play with.

Contact brides & grooms FREE! Only on www.shaadi.com.
Register now!

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<>.

[Non-text portions of this message have been removed]

HI gang...
Several people have written that they would appreciate something about 1/2
in diam.
The old engineering thing in me asks, what would happen if you took 4
capsules and
wrapped them together (faced the same way) all wired in paralell and then
into just
one FET as a follower... MMMMM I'm listening, so burn my ears off.
Connie

From: "Bob Andres" <robert.andres@...>

Does comb filtering not take effect when the mic spacing is greater than 1
wavelength? If placed so that their centers are 5/8" apart frequencies that
would cause concern would be = or > than 13560/.625=21,696 Hz. (I'm new to
this so let me know if I'm wrong. This applies to speaker line arrays so I
assume that it's also true for mic arrays.)

LOL... NO preorders don't help. I'll make some, seed a bunch to
those who added
their input and if they get the seal of approval, then I'll stock
some, THEN I will accept
paid orders, not before.

THEN we can move on to figuring out what the next item should be and
making it.



--- In micbuilders@..., "umashankar mantravadi"
<umashanks@h...>
wrote:

i would like to see it in two sizes one as small as possible, and

the other

about 1/2 diameter.The small one as omni, and the larger one both

omni and

cardioid.

i would like to see, instead of a the tiny hole on all panasonic

capsules, a

diaphraghm fully open , protected by a wire mesh, if necessary.

No fet and fet (if very good are both ok. i think the small capsule

must

have an fet. both should have three pads, so linkwitz are any other

future

system can be implemented without cutting traces. if the pads are to be
joined, they can always be joined up at the other end of cable, if

only one

uses two conductor plus shield capbling.

is that a very big wish list?

i will preorder if that will help. ( i live in india, but these days

i can

use my credit card to buy abroad(.

umashankar

We are putting our heads together to make a replacement for the

WM-61 that

is Linkwitz Mod ready, items to be nailed down are FET selection,

hole size

vs
no hole, etc.

I would like everyone's final input on the design so we do don't

have to do

it
over again.

It is being finalized over on micbuilders (the new group) If you

have any

input
on this, please post it over there as we just about ready to make

these and

anyone with input get's some to play with.

_________________________________________________________________
Contact brides & grooms FREE! Only on www.shaadi.com.
Register now!

Yahoo! Groups Sponsor
ADVERTISEMENT
<>



To unsubscribe from this group, send an email to:
micbuilders-unsubscribe@...



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