Reducing Bleedthrough from Guitar to Vocal Microphone

This article is an editorial and expresses the opinion and experience of the author. Please do not edit this page, but feel free to post comments in the discussion page. Thank you.

This article originally appeared in Bose^® Pro Portable PA Community and was written by community member User:Ted the musicman. Ted has place this here in the wiki for you to enjoy. [hr]

Hi Everyone  :)

Like most of the folks here I am delighted with my L1 Classic. I am especially happy with it since I found the solution to a problem I have been having for quite some time.

When I first got my L1™ ( months ago ) and plugged in my acoustic guitar I was amazed at the sound quality I experienced, it was perfect in my opinion. I had never heard my acoustic guitar sound that good.

Then I put a vocal mic in front of the system .... and, well, this is when things changed. Although the sound was still pretty good I could tell that the guitar EQ had changed and become thinner, not as rich and full. I also found myself spending a lot of time working on getting a vocal sound I was happy with.

After a little deliberation and experimentation it didn't take long to realize that the sound of the guitar and the vocal were being affected by bleedthrough and regeneration of their respective signals back through the vocal mic. I knew that the potential of the L1 was huge so I set out to find a solution to this particular problem.

I tried alot of the approaches I found here on the Bose forum, such as:

1. set the mic stand 2 to 3 feet off axis from the L1™
2. angle the mic 45 degrees off axis
3. try a hypercardioid mic ( OM5 )
4. use a gate on the vocal mic
5. move out at least 8 to 12 feet away from the L1™
6. eat the mic
7. all of the above

Using these techniques helped improve things incrementally but were not a 100% fix, even when I tried them all at once.

After alot of experimentation I finally hit on a complete fix that works well for me. I thought I would post it here in case it might benefit someone else, especially those of you that are using a harmonizer and occasionally getting wobbly harmonies that are not a result of your voice ( guitar bleed thru will do that to a harmonizer ).

So here is what I did :

1. I am using a TC Helicon Voicelive ( for harmonies ) as an insert on the vocal channel. So, I used it to add compression to the vocal channel. This boosted the vocal volume considerably and allowed me to turn the vocal channel down from 2 o'clock to 10 o'clock ( on the remote ). This had the effect of reducing the sensitivity of the vocal channel while still retaining a strong and powerful vocal volume and performance.
2. I also purchased a Crown CM 311A headset mic which is known for it's great isolation and feedback rejection properties. ( As an aside I have to say that this is an excellent mic, especially when combined with Cliff's wonderful preset. It is the best sounding mic I have tried to date thru the L1™, in my humble opinion )
3. I also left the gate ( via the Voicelive ) turned on, the threshold on the gate is set at -31db.

The end result of all this is that my bleed-thru concerns are a thing of the past. I get great isolation and separation of the guitar and vocals. No more crosstalk or bleedthru, no more wobbly harmonies from the harmonizer, no more coloration of the guitar or vocal preset. The guitar tone stays intact and unaltered as does the vocal tone.

What I get is full, rich, clear, detailed sound that really shows what an excellent job Cliff has done on the presets.

I have to admit I am horrendously picky about sound ( just ask my friends and family ) so it was a real delight to get this accomplished. It was also a great joy to hear just how much the system is capable of. Now I can get back to enjoying the music and the superb sound offered by the L1.

I think my tweaking days are numbered, hehe.

Ted

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