audio effects

2 Articles

Audio Effects Applied To Text

April 11, 2025 by 3 Comments

If you are a visual thinker, you might enjoy [AIHVHIA’s] recent video, which shows the effect of applying audio processing to text displayed on an oscilloscope. The video is below.

Of course, this presupposes you have some way to display text on an oscilloscope. Audio driving the X and Y channels of the scope does all the work. We aren’t sure exactly how he’s doing that, but we suspect it is something like Osci-Render.

Does this have any value other than art? It’s hard to say. Perhaps the effect of panning audio on text might give you some insight into your next audio project. Incidentally, panning certainly did what you would expect it to do, as did the pass filters. But some of the effects were a bit surprising. We still want to figure out just what’s happening with the wave folder.

If text isn’t enough for you, try video. Filtering that would probably be pretty entertaining, too. If you want to try your own experiments, we bet you could do it all — wave generation and filtering — in GNU Radio.

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Better Car Audio With Guitar Effects

May 13, 2017 by 18 Comments

Automotive sound is a huge deal; for many people, it’s the place to listen to music. Back in the 80s, you were lucky to get anything more than two door speakers in the front of the car. Fast forward to today, and you can expect a 10-speaker system in an up-spec’d family sedan.

[Josh] has a car, and wanted to improve the sound. In particular, the aim was to improve the sense of space felt when listening. A car is a relatively small space, and the driver sits in close proximity to the front speakers, so it’s difficult to get a good soundstage.

[Josh]’s approach was to create a “surround” effect for the car stereo, by feeding a left/right difference signal to the rear speakers. This was achieved by the use of a series of op-amps that buffer and then generate a mono signal that represents the difference between the left and right channel. For optimum results, [Josh] wanted to delay the signal being sent to the rear speakers, with a longer delay making the soundstage feel bigger, as if reflections are coming from farther away in a bigger room. To do this, [Josh] simply hooked up the signal to a Boss DD-3 Digital Delay guitar pedal – an off-the-shelf solution to an otherwise sticky problem. The DD-3 gives [Josh] a variable delay time with reasonably high fidelity, so it’s a perfect way to get the project done quickly.

The final piece of the puzzle is a filter. The difference signal doesn’t actually sound all that pleasant to the ears by itself, especially when it comes to transient high-pitched sounds like cymbals, so a lowpass filter is implemented to cut these higher frequencies down.

[Josh] made everything adjustable, from the filter to the delay, so it’s simple to dial things in until they’re just right, rather than relying on calculation or guesswork. The general idea is to feed the difference signal into the rear speakers at a low enough volume and with a subtle delay so that it adds to a general feeling of being in a larger room with the sound coming from all around, as opposed to listening to very loud point sources of audio.

It’s a cool project that we imagine would be very satisfying to dial in and enjoy on the road. What’s more, it’s a fairly straightforward build if you want to experiment with it yourself on your own car. Perhaps your problem is that you need an auxiliary input to your head unit, though – in that case, check out this Subaru project.