Making a beautiful Larsen

Talk about music gear for noise music

Moderator: xome

User avatar
Moonchild
Posts: 28
Joined: Sat Jul 09, 2016 5:14 am
Location: Fribourg, Switzerland
Contact:

Making a beautiful Larsen

Post by Moonchild » Tue Dec 18, 2018 5:37 pm

I want to record a beautiful modulated Larsen, and I know how to achieve what I want with a vocal microphone and a digital reverb, putting both of my hands on the mic to lower the pitch and modulating it by moving it farther/closer to the amp, but I want to try to use a contact mic, mainly because in my live setup I don't use vocal mic and eventually I want to be able to reproduce that sound live. Plus I want to get rid of the reverb because it makes the modulation slower and when I tried to just put a distortion on the vocal mic the Larsen is really tiny and high-pitched.

I know I can modulate the pitch of the Larsen using a wah, a sweepable EQ or a vcf and I found some pretty sweet spot using that technique (read "not as tiny"), but what a really want is the modulation to happen by itself or by moving the mic slightly, like I witnessed in pretty much every Noise show that I can remember (not much IRL so thank you internet).

And right now in my practice room, I just can't achieve that result. I don't have a lot of space and I have to move about a meter/3 foot to make something happen, and after that the Larsen stabilize, which is really not what I want. A pure continuous tone sounds boring as fuck to me even if the volume is as loud as possible.

Thinking about that I tried to amplify the sound further, crossing my finger that my neighbours wouldn't call the police because it was kinda late, and it was even more stable. At least it was not as tiny but - fuck! it wouldn't budge.

Do I need a bigger room? Do I need something silly like acoustic treatment? Do I need a real guitar amp (right now I'm using emulation)? Do I need more distortion/fuzz/...? I have at least 2 per channel, do I need a third one?

I really don't know what to do, and I can't afford to try everything obviously... Please help! :(



User avatar
timdrage
Posts: 5106
Joined: Sun Feb 05, 2006 11:08 am
Contact:

Re: Making a beautiful Larsen

Post by timdrage » Wed Dec 19, 2018 5:07 am

universal answer to contact-mic-related issues: try getting/building a contact mic preamp to match the impedance and thus get a better frequency response

can't promise anything tho

User avatar
Moonchild
Posts: 28
Joined: Sat Jul 09, 2016 5:14 am
Location: Fribourg, Switzerland
Contact:

Re: Making a beautiful Larsen

Post by Moonchild » Wed Dec 19, 2018 7:53 am

Thank you!

User avatar
timdrage
Posts: 5106
Joined: Sun Feb 05, 2006 11:08 am
Contact:

Re: Making a beautiful Larsen

Post by timdrage » Wed Dec 19, 2018 7:59 am

also if you are searching noise forums etc for this info then "feedback" or "howlround" are the english words for 'larsen' :)

User avatar
WhiteWarlock
Posts: 2010
Joined: Tue Apr 10, 2018 7:58 am

Re: Making a beautiful Larsen

Post by WhiteWarlock » Wed Dec 19, 2018 9:13 am

Image
attach/glue piezo to piece of cork....
then put under strings before the bridge
firmly pressed to body
seen that with old cello/bass/viola pickups
no clue what your larson looks like
the cork method will transfer the sound way better for electrical output
Dearmond was using this method in the 1940s/50s for classic acoustic stringed instrument pickups
http://www.musicpickups.com/dearmond-numbered-products/

User avatar
timdrage
Posts: 5106
Joined: Sun Feb 05, 2006 11:08 am
Contact:

Re: Making a beautiful Larsen

Post by timdrage » Wed Dec 19, 2018 4:42 pm

WhiteWarlock wrote:
Wed Dec 19, 2018 9:13 am
no clue what your larson looks like
Larsen is just a lesser known / less english name for feedback :)

https://rahulsamuel.wordpress.com/tag/larsen-effect/

User avatar
WhiteWarlock
Posts: 2010
Joined: Tue Apr 10, 2018 7:58 am

Re: Making a beautiful Larsen

Post by WhiteWarlock » Wed Dec 19, 2018 6:02 pm

Larsen also makes vintage acoustic instruments
didn't register the term term "Larsen" really...
besides GX showing me his noise belt while we drank beer at his house long ago
~shrug~
my bad
makes more sense now

User avatar
xdugef
Posts: 13776
Joined: Tue Jun 14, 2005 11:26 am
Location: 噪声æº￾
Contact:

Re: Making a beautiful Larsen

Post by xdugef » Wed Dec 19, 2018 8:24 pm

timdrage wrote:
Wed Dec 19, 2018 4:42 pm
WhiteWarlock wrote:
Wed Dec 19, 2018 9:13 am
no clue what your larson looks like
Larsen is just a lesser known / less english name for feedback :)

https://rahulsamuel.wordpress.com/tag/larsen-effect/
Go figure!

Image


User avatar
WhiteWarlock
Posts: 2010
Joined: Tue Apr 10, 2018 7:58 am

Re: Making a beautiful Larsen

Post by WhiteWarlock » Thu Dec 20, 2018 8:50 am

actually been doing this with customized opamp VCF design recently... 2-3 days
using patched feedbackoop overdrive
output into mixer into input
(there are multiple inputs)
generate the sine wave)feedback/larsen/whatever)
that stage can also be modulated/effected
plus other sound sources can also be added into filter(overloaded noise)
then modulate frequency
and also resonance
plus can use that signal or further patching/FX
does that count?
the feedback loop is used as source input(think.... how do you achieve resonance in circuit?)
can do it also with microphone and preamp into filter and crank the output volume for getting sine
placing microphone in front of speaker
or placing guitar in front of amp
ring
next.........................................................................................................................................................

User avatar
Moonchild
Posts: 28
Joined: Sat Jul 09, 2016 5:14 am
Location: Fribourg, Switzerland
Contact:

Re: Making a beautiful Larsen

Post by Moonchild » Fri Dec 21, 2018 7:09 am

timdrage wrote:
Wed Dec 19, 2018 4:42 pm
WhiteWarlock wrote:
Wed Dec 19, 2018 9:13 am
no clue what your larson looks like
Larsen is just a lesser known / less english name for feedback :)

https://rahulsamuel.wordpress.com/tag/larsen-effect/
Oh shit! Didn't realize that... Thanks for clarifying my mistake.

User avatar
crochambeau
Posts: 2829
Joined: Sat Nov 19, 2005 12:48 pm
Location: earth.
Contact:

Re: Making a beautiful Larsen

Post by crochambeau » Fri Dec 21, 2018 7:28 am

For an acoustically coupled wide pitch range operation, you're going to need to mitigate highly resonant stages that will act as a bandpass (which kind of anchors your frequency at a certain point).

Contact microphones are generally pretty spiky when it comes to resonances, due to the means by which they operate. So you may have an uphill battle.

Initially I was just going to say "when it comes to controlling pitch in an acoustic feedback process, sometimes less gain/volume is more" but your criteria of wanting to employ contact microphones complicates things.

Perhaps determining the resonant frequency of whatever material the contact microphone is using as a collector, and then heavily damping or notching that frequency out with a filter or EQ, and seeing if you can somewhat level the playing field enough to be able to nudge the resulting oscillation around to your whim.

A ton of stuff comes into play, standing waves in the room/etc. but for starts I would try to just use *subtractive* equalization and amplification and see where that gets you.

User avatar
WhiteWarlock
Posts: 2010
Joined: Tue Apr 10, 2018 7:58 am

Re: Making a beautiful Larsen

Post by WhiteWarlock » Fri Dec 21, 2018 9:16 am

you can also try playing with 31 band eq on your microphoine...
that 's used for ringingout room(minimizing feedback)in live sound
thus you can push/pull add/subtract frequencies in the room feedback/larsen whateva

Post Reply

Who is online

Users browsing this forum: No registered users and 2 guests