Why Another Convolution Reverb When There Are Already So Many?

What sets iamReverb apart from other convolution reverb plugins – and why did we record real acoustic spaces with up to 25 different microphones?

Rethinking Convolution Reverb

When we talk about recording vocals or instruments, we often find ourselves philosophizing and enthusiastically discussing our favorite microphones and microphone preamps. Out of the countless options available, we’ve tried many and formed our own opinions. We know how dramatically the same instrument can sound different depending on the microphone or preamp used.

But how much do we actually know about recording room – or about creating impulse responses?

Is it enough to simply play a sine sweep through a loudspeaker and record it with measurement microphones?

Our answer is: No.

The Importance of the Room in Recording

The room is one of the most defining elements of any recording. Even if the microphone, preamp, and instrument remain the same, a different room can completely transform the sound. Size, shape, materials, reflection behavior, and even small details such as furniture or curtains influence how a signal spreads throughout the space and returns to the microphone.

This is exactly the behavior that a convolution reverb attempts to reproduce. The impulse response is essentially the acoustic “fingerprint” of a room. It describes how a space reacts – how early reflections, reverb structure, and frequency response interact.

However, while the idea sounds simple, its implementation is anything but.

Why Not Every Impulse Response Sounds the Same

In practice, an impulse response is usually created using a sine sweep: a loudspeaker plays a sweep that is recorded by microphones and later deconvolved to an impulse response. These are the basic principles of the method – but the result depends heavily on the quality of the entire signal chain.

Some of the key factors include:

the loudspeaker used and its directivity characteristics
the microphones and their positioning
the quality of the preamps and converters
the dynamic range and distortion-free playback
the ratio between direct sound and room contribution

If these elements are not chosen carefully, the room will not be captured neutrally or in full detail. Instead, the resulting impulse response will reflect the measurement system more than the room itself.

The Difference Between Measuring and Recording

Many impulse responses are created with the goal of measuring rooms. For acoustic analysis, this is perfectly sufficient – here the focus is primarily on objective parameters such as reverberation time or frequency response.

For musical applications, however, our goal is different: we want to record rooms.

That may sound like a subtle distinction, but conceptually it is a major one. Recording a room is not only about obtaining a technically correct measurement. It’s about capturing a space that feels musical, creates depth, and blends naturally into a production – much like choosing the right microphone for a vocal recording.

Our Approach with iamReverb

When creating the impulse responses for iamReverb, we therefore treat the room much like an instrument or a recording environment. We consider not only the space itself, but the entire acoustic chain.

This includes, among other things:

carefully selected loudspeakers with a natural radiation pattern
high-quality studio microphones instead of pure measurement microphones
multiple microphone positions and distances
a signal chain that resembles music production more than laboratory measurement

This approach allows us to capture not only the room, but also its musical character.

Why This Matters for the Sound

When an impulse response truly conveys the spatial depth and structure of an environment, convolution reverb creates a very different sense of space. Reflections sound more natural, the reverb blends better into the mix, and the positioning of instruments becomes clearer.

This is exactly where iamReverb comes in: not by delivering as many rooms as possible, but by providing spaces with a sonic quality that feel like a real recording environment.