Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Parts Where to get, and how to make the best bits. PCB's, caps, transformers, etc.

Electret microphone question
Electret microphone question
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 16th July 2007, 03:38 PM   #1
zobsky is offline zobsky  India
diyAudio Member
 
zobsky's Avatar
 
Join Date: Mar 2002
Location: Dallas, Tx, USA
Default Electret microphone question

I should be getting my panasonic mic capsules today. Intended purpose is to measure loudspeaker response.

I need to wire up the mic capsule.

Option 1. Build a simple mic pre-amp to power the capsule (powered by battery)
Option 2. Use the 5V bias on my sound card for the same purpose

These options are described at the bottom of the page http://www.tkk.fi/Misc/Electronics/c...tretinput.html

Questions:
1. How come I never see option 2 recommended for DIY audio purposes (although I guess cheap headset mics use exactly this method)?

2. For option 2, wouldn't I still need a DC blocking capsule inline with the mic capsule ?
__________________
"Not everything that can be counted counts, and not everything that counts can be counted." - Albert Einstein
  Reply With Quote
Old 16th July 2007, 05:08 PM   #2
SY is offline SY  United States
On Hiatus
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Electret microphone question
Well, it's not like they've got a screamin' high output. Getting some voltage amplification and low source impedance locally makes the whole interfacing issue much easier. I used a single battery-powered opamp configured for 40dB of gain, and that gets the levels just right for the sound card I use.
__________________
"You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is."
  Reply With Quote
Old 16th July 2007, 05:41 PM   #3
Juergen Knoop is offline Juergen Knoop  Germany
diyAudio Member
 
Juergen Knoop's Avatar
 
Join Date: Jan 2007
you could connect the capsule without any interface to the mic input
sadly the soundcards mic-input has no flat frequency response
the picture shows my onboard cmedia-card. This one of the flatter frequency responses I have seen
my older computer had a really worse mic-input
regards
Attached Images
File Type: jpg soundkarte.jpg (72.4 KB, 380 views)
  Reply With Quote
Old 16th July 2007, 05:57 PM   #4
zobsky is offline zobsky  India
diyAudio Member
 
zobsky's Avatar
 
Join Date: Mar 2002
Location: Dallas, Tx, USA
Thanks to both the posters. Those were the answers I was looking for. I'll build a pre-amp.
__________________
"Not everything that can be counted counts, and not everything that counts can be counted." - Albert Einstein
  Reply With Quote
Old 16th July 2007, 07:17 PM   #5
Juergen Knoop is offline Juergen Knoop  Germany
diyAudio Member
 
Juergen Knoop's Avatar
 
Join Date: Jan 2007
this is just something to be aware of
your soundcard may be fine
  Reply With Quote
Old 16th July 2007, 07:44 PM   #6
zobsky is offline zobsky  India
diyAudio Member
 
zobsky's Avatar
 
Join Date: Mar 2002
Location: Dallas, Tx, USA
Quote:
Originally posted by juergenk
this is just something to be aware of
your soundcard may be fine
I'll try a loopback from sound card(Audigy 2) to mic input with TrueRTA. That should tell me.

Also, is there any disadvantage to the simple mic-preamp I linked to in my first post (apart from a possible issue driving long lengths of cable)? I only intend to use a meter or two for my application.

Thanks
__________________
"Not everything that can be counted counts, and not everything that counts can be counted." - Albert Einstein
  Reply With Quote
Old 16th July 2007, 08:02 PM   #7
Juergen Knoop is offline Juergen Knoop  Germany
diyAudio Member
 
Juergen Knoop's Avatar
 
Join Date: Jan 2007
the circuit is for interfacing a dynamic microphone faking it into a electret one.
it won't work with a electret capsule
  Reply With Quote
Old 16th July 2007, 08:15 PM   #8
zobsky is offline zobsky  India
diyAudio Member
 
zobsky's Avatar
 
Join Date: Mar 2002
Location: Dallas, Tx, USA
Quote:
Originally posted by juergenk
the circuit is for interfacing a dynamic microphone faking it into a electret one.
it won't work with a electret capsule
That's true for for the first circuit on the page, .. not for the ones way down using a battery and a resistor & capacitor.
__________________
"Not everything that can be counted counts, and not everything that counts can be counted." - Albert Einstein
  Reply With Quote
Old 16th July 2007, 08:22 PM   #9
SY is offline SY  United States
On Hiatus
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Electret microphone question
Take a look at the Mighty Mike article that Joe d'Appolito wrote. It's a very simple circuit that works great.
__________________
"You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is."
  Reply With Quote
Old 16th July 2007, 08:25 PM   #10
Juergen Knoop is offline Juergen Knoop  Germany
diyAudio Member
 
Juergen Knoop's Avatar
 
Join Date: Jan 2007
Quote:
using a battery and a resistor & capacitor.
thats not needed with a mic-input
regards
  Reply With Quote

Reply


Electret microphone questionHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Electret Microphone Capsules cm961 Parts 12 6th February 2012 10:24 AM
Matching transistors for electret microphone? cafh Everything Else 3 12th April 2007 11:16 AM
Balanced electret microphone circuit scone Multi-Way 3 1st February 2005 08:16 AM


New To Site? Need Help?

All times are GMT. The time now is 02:01 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki