Speaker and Cab simulators

Stompboxes circuits published in magazines, books or on DIY electronics websites.

Re: Speaker and Cab simulators

Postby Cub » 28 Mar 2016, 15:02

Any time, phatt ! :mrgreen:

I figuered Frank's work might be helpful or at the very least, interesting.

You're right about what a speaker sim actually does, it's "just a filter" and I wish there was a simple (stomp)box with a filter inside that was modelled after a really good sounding example of one of those digital cab impulses.

Taking the graphs of a speaker as a starting point is one thing. But these graphs never show how the speaker actually sounds in an enclosure with one or three compadres and different microphones with different placements also have their impact on the sound.

I wish I had the knowledge to come with such a box.
I wish I were a chestnut tree, nourished by the sun.
With twigs and leaves and branches and conkers by the ton.
User avatar
Cub
Resistor Ronker
 
Posts: 278
Joined: 29 Aug 2011, 08:14
Location: The Netherlands
Has thanked: 54 times
Have thanks: 58 times

Re: Speaker and Cab simulators

Postby Bloodman » 07 May 2017, 11:08

ADA GCS-2 guitar cabinet simulator
You do not have the required permissions to view the files attached to this post.

For this message the author Bloodman has received thanks:
rcustoms (08 May 2017, 01:48)
Bloodman
 
Posts: 21
Joined: 25 Mar 2016, 10:51
Has thanked: 13 times
Have thanks: 23 times

Re: Speaker and Cab simulators

Postby teemuk » 12 May 2017, 18:19

Cub wrote:You're right about what a speaker sim actually does, it's "just a filter" and I wish there was a simple (stomp)box with a filter inside that was modelled after a really good sounding example of one of those digital cab impulses.


The virtue od digital signal processing (like "impulse response" processing) is that very complex filters can be introduced. Analog filters that could in utmost detail model the response curve of a speaker system would be very complex circuits.

Taking the graphs of a speaker as a starting point is one thing. But these graphs never show how the speaker actually sounds in an enclosure with one or three compadres and different microphones with different placements also have their impact on the sound.


Some of that stuff is easy to approximate, though:
- The axis tone generally contains most high-frequency energy. Unless the speaker is omni-directional (not aware of any that are) high frequency energy decreases off-axis. The exact frequency at which the response starts tapering off is therefore mathematically related to the acoustical size of the driver. So, this characteristics is quite easy to model with a variable shelving hi-pass filter.
- In an "acoustically suspended" closed cabinet, smaller dimensions will damp the resonant peak and shift resonant frequency upwards. In "infinite baffle" closed cabinet resonance and damping remains about equal to free-air system.
- Larger baffle dimensons will result to lesser amount of damping and attenuation of low frequencies around resonant frequency. Both these characteristics can be modeled to good extent with variable shelving lo-pass filter.

For this message the author teemuk has received thanks:
FiveseveN (12 May 2017, 21:00)
teemuk
Breadboard Brother
 
Posts: 132
Joined: 17 Aug 2009, 20:54
Has thanked: 3 times
Have thanks: 49 times

Previous

Return to DIY Stompbox designs

Who is online

Users browsing this forum: No registered users and 6 guests