Skip to main content
Blues Harmonica logo

User Account

Username:*
Password:*
Forgot Your Password?

Visitor Menu

  • Sign Up
  • Sample Lesson #1
  • Sample Lesson #2
  • Student Recordings
  • Forums
Forums :: Ask Harp Mic Expert Greg Heumann

CM variation

2 replies [Last post]
Sat, 08/25/2012 - 17:34
Dave Hall
Dave Hall's picture
Offline
Level 3
Joined: 05/08/2010

Hi Greg,
I have 2 CM-equipped mics, an ev605 any a JT 30. They sound quite different, and respond to cupping very differently too. I think the EV sounds like it is already cupped; there is nowhere near as much difference holding it 1 handed as there is with the JT. The ev is very strong bottom heavy sounding mic though, not as much tonal variation as the JT.
I'm wondering whether this difference is mainly down to the elements; does the type of shell significantly alter the sound?
I'm thinking of installing a CM element in another JT 30 shell and wondering if it's likely to be significantly different to the mics I already have.
Thank you,
Dave

Top
Sat, 08/25/2012 - 19:16
#1
Greg Heumann
Greg Heumann's picture
Offline
Expert
Joined: 04/29/2010
CM element variation

This is my first post here as Fritz' replacement. I learned a great deal from Fritz and will miss him. It is with very mixed feelings that I assume this responsibility. I hope I can do half as good a job at answering your mic questions!

OK, Dave

There is variation between CM elements - especially if they are different models. The dual impedance CM's, found in the 520D green bullet mic, among others, almost all called 99S556 - tend to be brighter and harsher than the single impedance elements, the 99A86 and 99B86 the most common among those. And even those vary with age - the very oldest 99A and 99B86 CM elements were made using a different glue holding the pin to the diaphragm than the remainder of production - and you can hear the difference - the old ones getting closer to a CR element in terms of the character of their breakup. But even among identical models, there is indeed some variation from element to element.

With all that said though, the amount of air space behind the element has a definite impact on tone, and it is important that the mounting system and gasket seal the front of the element from the rear. The EV605 has more airspace behind the element than the JT30 shell does. It would be easy enough to experiment by stuffing the rear part of the mic full of foam rubber or even dense cotton (Like cotton balls) to see if it makes a difference you like.

Also, the distance the element is from the harp makes a difference and different shells place the element at different distance from the player.

I think you'd find it very educational to simply swap the two mics' elements. Then you'll know whether the differences you are hearing are from the shell or the element.

Top
Sun, 08/26/2012 - 22:25
#2
Dave Hall
Dave Hall's picture
Offline
Level 3
Joined: 05/08/2010
Thanks

Thanks Greg, I think I probably didn't putt question very clearly, I've found the answer in something else you wrote about the difference between elements.
I agree it would be an interesting exercise to swap them over, however the EV is very tightly put together. I believe it houses an early 70s 99B86, but I've never had it open to look. Ron Sunshine sold it to me, said he couldn't get it open, and I haven't either. I guess if the time comes a way will be found but for now, as it ain't broke I'm not fixing it.
The JT is a 1959 99G86. Not as bottom heavy, greater range. A more musical mic to my ears, but requires a bit more concentration to get the best from it. the EV does the job for these hard rocking gigs.
I saw elsewhere you wrote of the difference between elements of the same type. I think I'll just take a punt and put together another JT with a CM.
Thanks again,
Dave

Top

Sign me up!

The low monthly subscription of $16.95 gives you full access! We accept major credit cards and PayPal.

Subscribe

Free Sample Lessons

After watching the BluesHarmonica.com overview video, try one of the lessons below to experience a lesson at BluesHarmonica.com.

  • Tongue Blocking Study 2 – This study is for the newer player or the player new to tongue blocking
  • Bending Study 5 – This is for the advanced player looking to improve their bending skills

Contributors

  • Aki Kumar
  • Joe Tartaglia
  • Gary Smith
  • Mark Hummel
  • Joe Filisko

Site Links

  • About David Barrett
  • Accredited Instructors
  • Links
  • Terms and Conditions
  • Contact Us
Hohner
© 2009 - 2022 David Barrett and the Harmonica Masterclass Co. for Bluesharmonica.com