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

Mic Cable Lengths

3 replies [Last post]
Fri, 06/08/2012 - 06:53
Rickx46
Rickx46's picture
Offline
Joined: 05/05/2012

Hello Fritz,
First of all, I am of the understanding that a high impedance mic cable should be limited in length to 18- 20 feet.
I also understand that when using a low impedance mic, that the cable can be of much greater lengths.
Therefore, does it follow suit that if you are using a low impedance mic .... plugged into a high impedance amp... by way of a "low to high" impedance matching transformer..... that the section of cable between the mic and the transformer is considered low impedance, and can therefore be of much greater length, if necessary?
I know it seems like I've answered my own question, but when it come to electricity, I often find my logic is wrong.
Secondly, concerning effects pedals..... Is it safe to say they should always be placed in line AFTER the transformer (and then directly into the amp)?
Appreciate any/all comments.
Thanks!
Rick

Top
Wed, 06/13/2012 - 20:37
#1
Mic Expert Frit...
Mic Expert Fritz Hasenpusch's picture
Offline
Joined: 01/16/2010
MIC CABLES -AND A MIC MORSEL

Yep, you're on the right track regarding impedance and its applications, Rick. HI-Z cables in excess of the optimum 18 feet (Aprox.) will show the onset of more RF (radio frequency) noise as they tend to act as antennae, while surrendering a progressively higher degree of their signal content -especially in the higher frequencies. You might not notice these divergent curves over the first few additional feet, but eventually they'll start to show.
Generally speaking, if there's going to be a mix of HI-Z and LOW-Z gear and wire, try to make the long runs of cable within the LOW-Z portion of the spaghetti. The benefits are less line loss and less noise acquired.
MIC MORSEL: As for introducing EFX pedals into the LONG CABLE chain: If placing the (HI-Z) pedals within immediate access range is important and your mic is HI-Z as well, make the short run from mic to the pedals in HI-Z, then into a HI-Z to LOW-Z matching transformer for the LONG CABLE RUN and reverse the transformer (LOW-Z to HI-Z) at your amp. If your mic is LOW-Z, then you could go from Mic into a LOW-Z to HI-Z matching transformer at the pedals and then to your amp; Exceptionally long cable runs? You could go mic-to matching trans-to EFX pedals -and back to LOW-Z via another matching trans for the LONG CABLE RUN prior to a final matching LOW-Z to HI-Z trans into your amp. If your amp has an EFX loop, run the pedals in and out utilizing that loop. Loop levels seem a bit hotter and less susceptible to BZZZZZZ ...

Top
Fri, 06/15/2012 - 06:40
#2
Rickx46
Rickx46's picture
Offline
Joined: 05/05/2012
Mic Cables ~ Mic Morsel

WOW!
You answered questions I hadn't even figured out how to ask yet!
Great to know you can do all those impedance switching tricks by use of the transformers.
Your detailed answer is VERY helpful ... and very much appreciated!!
Thank you Sir!

Top
Thu, 06/21/2012 - 10:46
#3
Mic Expert Frit...
Mic Expert Fritz Hasenpusch's picture
Offline
Joined: 01/16/2010
Mic Cables -And a Mic Morsel

Hello Rick,
While it may not always be a pleasure to "straighten-out" this cable business, it does pay dividends when things WORK as intended. By all means take the time and initiative to experiment with various HI-Z / LOW-Z combinations to see what the sonic effects might be.
I've got another wire-related Mic Morsel on the way...

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