Hi, i had looked into this before (not in PD). When you search for the modelling of a metal helix you'll get into intense math pretty quickly

(see https://www.era.lib.ed.ac.uk/bitstream/handle/1842/3718/BilbaoS_A%20Virtual%... )

so i decided to copy params from typical spring reverbs into delay chains. A simple version looks like this two delay chains, 25 and 40 ms (typical accutronic spring tank from guitar amps), each with feedback through an allpass filter, which should allow to smear the HF usually in a range of max 1ms. add faders for

• the delay time (ratio 2.5:4 - i prefer to have a range of 2.5 to 125 for the 25ms delay chain, the second delay chain x 1.6),
• the amount of feedback
• the amount of smear on the feedback.
• a control for randomization (see LFO thing below)

Unfortunately i am not aware of an allpass filter object for PD, as i use only vanilla, but i am sure you'll find one.

Additionally, to create more interesting pictures, you can

• add an LFO per delay chain with a line object set to 500 (to create a sort of glide) to modulate the delay time slightly or heavily.

Like i said, i didn't do this in PD yet, only in maxmsp and on patchblocks, but the idea works fine (gritty!) without heaving to go into heavy math.

My patchblocks patch is here: http://patchblocks.com/groups/patch/shattuh-02-spring-reverb-emulation

And someone made a video of how it sounds here (patchblock on right side runs the shattuh patch: https://www.youtube.com/watch?v=4_e3hrkLRAc

Best of luck :)

jayrope

www.kliklak.net/jayrope/ www.aircushionfinish.com www.soundcloud.com/jayrope www.ello.co/jayrope

On Apr 16, 2016, at 12:00 PM, pd-list-request@lists.iem.at wrote:

Message: 2 Date: Fri, 15 Apr 2016 15:06:00 -0400 From: William Huston williamahuston@gmail.com To: "pd-list@lists.iem.at" pd-list@lists.iem.at Subject: [PD] Spring Reverb? Message-ID: CAOTwkqBrWTPkQ2M5HEkQUoBdE3L4PUJeCj3MbBHzNwEwTpBMeA@mail.gmail.com Content-Type: text/plain; charset="utf-8"

Can anyone give any insight on how to model the sound of a spring reverb?

Is it possible by using Freeverb with some filters? Or does it require IR/Convolution?

I live the twangy rattle sound. So unique.

Thanks.