Introducing the world of Digital Room Correction (DRC), a process where digital filters are used to correct speaker + room aberrations. A 3 step process yet an acoustical challenge where DSP & Math Gurus use all resources to solve this complex problem. The following lines will summarize the basics of room correction in a setup involving a PC/Mac with a measurement/filter generation software, a measurement microphone and an audio processor (OpenDRC).
Step1: Measurement
The first step in any Room correction process is to "listen" to the room + speaker interaction. Using a a software + measurement microphone combo, a set of test sweeping tones are played back through your speaker systems and recorded by the software application. No doubt that your neighbors will be wondering what you're up too! However please don't despair, because providing you do it well, it will lead to great results and they will be the envious one... Back to the technical aspect, the sweeps are used to "measure" the response in both time and frequency of your system. Since the resulting impulse response will be key to the filter generation (step2), this step is key to your success.
Step2: Filter generation
At the center stage of "good to great" room correction fitlering is the array of math and psycho-acoustic models used to "generate" filters based on the measurement. In audio, two types of filters are typically used: IIR (Infinite Impulse Response) or FIR (Finite Impulse Response). You can read in more details their specifics here. In today's realm, most room correction filters are either FIR based or a combination of FIR + IIR filters. While each software has a different interface and its ways to calculate the filters, a comon element is the"target curve". In other words, the expected frequency response and a guideline for the filter generation.
Step3: Filter processing
Your filter settings are now ready and it's time to listen to the end result. This is where miniDSP's processor play a key role. What used to be a noisy/power hungry PC running in the middle of your Hifi set is now a low cost, low power yet powerful processor thanks to the introduction of miniDSP's room correction units. With a range of input/output configuration, we got you covered! It is a set and forget where the end user still get a chance to tweak some settings by allowing end users the flexibility they expect in today's world.
How to get started ?
You're ready to try miniDSP's room correction experience and want to know what's required. Here are the basic core element for a stereo configuration:
- 1 x Dirac Live unit for processing of the stereo signal. We have a wide range of options so make sure to check our our DDRC and SHD series.
- 1 x Measurement microphone such as miniDSP UMIK 1.
And that will be it for you to be ready to go!