Experienced only: What have you done with room correction?

Erik,

Full disclosure: We design and manufacture speaker systems (in the USA) that use full DSP, specifically digital crossovers and room correction.

First, DSP (Digital Signal Processing) is a broad term. Basically, anywhere there is digital signal there is DSP. Digital crossovers and room correction are a subset of DSP.

DSP/room correction (DSP/RC) can be much more than amplitude correction, often refereed to EQ. DSP/RC users only applying EQ are using only part of the technology's capabilities. There are simple units that are basically digital equalizers.

Comprehensive DSP/RC systems compensate for amplitude domain and time domain anomalies. Don't underestimate the importance of time domain corrections.

During the development of our Apollo series speaker systems we studied analog passive crossovers, analog active crossovers and digital crossovers for them. We developed the Apollos using all three technologies. Exploring digital crossovers allowed us to experiment with DSP/RC. We found that there are two basic categories: Manual, that requires much experience to sort out and semi-automatic, which are more user friendly. Our supplied DSP unit is user friendly.

We found that applying DSP/RC to a poorly designed speaker doesn’t automatically turn it into a gem. What we did prove to ourselves is that applying DSP/RC to a good speaker allows that speaker to get much closer to its full potential and do so in a much greater variety of listening rooms. And in many cases, improve the measured performance. Time domain issues inherent in the design are corrected.

IMHO, I have found that properly applied high quality DSP/RC makes the system sound more balanced from top to bottom, improves resolution, improves dynamic contrast, eliminates stress and just sounds more complete.

BTW, ASP (Analog Signal Processing) is a term not often used by audiophiles. Basically, anywhere there is an analog signal there is ASP. Technically, ASP/RC can be developed and applied to a system.

I've used a couple of versions of Anthem's ARC over a decade or so, with many loudspeakers. On general principles, I turn it on only if the positive effect on smoothing in-room frequency response seems "worth it" and the better the resolution of your system is, the easier it is to hear the software doing its thing.

Three observations:

1. After the measurements are made, I inspect the in-room response curves and apply RC only up to the lowest frequency at which it seems to be making a meaningful difference. Ideally, no higher than 500Hz, never more than 2000Hz.

2. Attempting to correct a dip in FR is much less likely to help the cause than a judicious trim to a peak.

3. The benefits for a multichannel system are especially evident.

4. Having capable DSP room correction won't eliminate the need for room treatment with physical measures in certain situations.

@jeffseight 

i was pondering a low cost experiment with the DSpeaker system for about $300, but when I noticed the analog in/out I started thinking about the extra D/A conversion and decided for now to focus on room treatments, which is also what the above responses suggest anyway.  Will be giving GIK a call next week…

My experience with room correction involves two different correction systems.  The first DSP/RC was part of Sanders 10 speaker system.  Roger Sanders programmed and included a dbx VENU360 DSP/digital crossover with the system purchase of his 10 series electrostatic speakers.  I bought a dbx from Sanders to use with Innersound EROS speakers.  The EROS speakers are the predecessors to his Sanders 10 speakers.  The crossover portion of the dbx is necessary for use with Sanders or Innersound speakers.  The DSP/RC RTA (real time analyzer) in the dbx is set up using a microphone.  Full set up process is easy to do and gives the music the right weight and resolves room and bass resonances.  In other words, the music sounds really good!  Check the Sanders web site for more information.

My current RC system is a Lyngdorf TDAI 2170.  While this unit is an 80 watt integrated amp with Room Perfect room correction, I don't use the amp portion of the 2170.  The 2170 is very flexible and I can use it as just a preamp with Room Correction, which I do. Room Perfect allows me to set the crossover point for the high pass and low pass filters so I send the high pass to a Sanders Magtech amp which drives Magnepan 3.7i speakers.  The low pass is sent to a Dayton Audio sub amp driving four AudioKinesis subs.  Room Perfect room corrects by analyzing, via a microphone, various test tones and sweeps taken from random microphone placements (usually seven or eight locations) in the room.  The correction produces a sound without the negative influences of the room.  The bass is clean and articulate (though I believe the four sub system from AudioKinesis has a lot to do with that).  Soundstage, depth and detail are outstanding.  The sound I hear makes my toes tap and when my toes are tapping I know the sound is good.  Hit the Lyngdorf website for more information.

Passive room treatment (if it's allowed) is always the best first choice.