I've been interested in IR technology for a while now, but haven't seen many samples of its capabilities for acoustic swing and jazz style guitar, which is primarily my focus. The benefit of this over a microphone is the plug-and-play nature of a piezo pickup (ideally a single input jack), and better feedback resistance. However, piezo's tend to sound boxy and "quacky".
The Nux Optima AIR is an affordable acoustic guitar Impulse Response modeling + Preamp EQ pedal. It can transform the sound of your piezo pickup into something much closer to a microphone. You may have heard of the ToneDexter, the first product to do this. Since then, there's been offerings from L.R. Baggs and now Nux.
How do these sorts of pedals work? In short, you program it by playing with both a microphone and your piezo pickup plugged into the pedal simultaneously. It records a sample of both, and calculates an "impulse response" algorithm that will translate your pickup to the frequency profile of the microphone in real time.
I put it to the test with the cheapest piezo I could get off of Amazon. The pickups were stuck on with removable adhesive putty.
For all tests, I played and recorded the same audio in the following order:
- Straight piezo
- Nux Optima Air IR switch enabled, with my own programmed IRs for the instrument
- A condenser microphone (Joemeek JM27 small diaphragm)
- Nux Optima AIR IR again, but with some EQ (boosted highs, lower mids) to try to match the sound of the mic.
Conclusions: I think it's really impressive! But needs some EQ to dial it in. You really do need to put in the time to program your own IRs to get the most out of this. Using the stock ones are not great at all.
You can download the IRs I created here (note you need to cut and paste this URL into your browser, clicking it from this forum doesn't seem to work):