From what I can ascertain I'm supposed to change the distance on one of the subs and measure and see how it starts impacting the dip around the crossover?
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Audyssey's Next Generation of Room Correction (MultEQ-X)
- Thread starter sweetchaos
- Start date
Does this sound right to you?
Speed of sound varies a bit with temperature/humidity, so treat these as precision starting points, then dial in by measurement.
I'll be able to work on this tomorrow.
- Keep both subs’ physical phase at 0°.
- In the Denon: Setup → Speakers → Manual Setup → Distances → Subwoofer 2.
- Jump to one of the offsets above (e.g., +3.5 ft for ~90° at 80 Hz).
- Re-measure; if the dip worsens, try the opposite direction (i.e., subtract instead of add).
- Once close, fine-tune in 0.1 ft steps.
Speed of sound varies a bit with temperature/humidity, so treat these as precision starting points, then dial in by measurement.
I'll be able to work on this tomorrow.
Last edited:
So I added 3.5 ft to sub #2 and measured. Then I subtracted 1ft from the original position. Both measurements are exactly the same so it seems that the subs are aligned, but somehow not with the mains. Edit. I was able to play around with ChatGPT and I think I have the subs better timed to the mains now, had to reduce the distance on both subs by -5.6. Thanks for the eye on this and the encouragement. Edit: The more I listened the more it didn't sound right. I put everything back to where it was where I said it was the best I've ever heard...and it still is...and it's staying there! haha P.S. I changed my 1st order bass shelf to a 2nd order bass shelf and wow did that ever tighten things up and remove mid-bass bloat between 70-100.
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nathan
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The challenge with ChatGPT is that it does not know what information is correct and which isn't. It just synthesizes what it reads. So it is a useful tool but often suboptimal for problem solving that doesn't lend itself to a solution based on summarizing existing texts.
In any event, hopefully it led you down the path of:
1. Time align the subs with each other. This can be done with distance settings (delay) or often just with phase settings. In a two sub system, one sub would be at zero distance/delay/phase, and then the other sub you would step through distance options (or phase) incrementally, measuring each time, until you see the greatest summation of output with the fewest dips. At that point, the subs are aligned with one another. There are at two popular tools for this: 1) using the phase knob on one sub; 2) using an external DSP like a miniDSP. Using the distance setting on the AVR even if it allows addressing one sub at a time is problematic because more room EQ systems will override what you do here (and you have to do it BEFORE running room EQ not after).
2. Time align the collective "sub" (really many subs acting as one) with the mains. This is where you adjust both distance (delay) and the crossover frequency. Distance is usually adjusted in the AVR, a single value for the "sub" (group of subs that are playing in mono, and are already time aligned with one another) though it can be done in an external device like a miniDSP, as well. This is an iterative process, trying different distances until you find the one with the best linear response or at least fewest dips, in the crossover region. It gets a little complicated because you will ALSO do an iterative process to find the best crossover frequency, starting perhaps at 50hz and trying every 5 ish hertz up to 140. Chances are good some crossover points will result in the fewest dips. But the complexity is that these two variables (delay for the "sub", and crossover frequency) can interact a bit, so when you dial in one ideally, and then the other, the first one may need to be adjusted, and so on, until the best COMBINATION is found.
In any event, hopefully it led you down the path of:
1. Time align the subs with each other. This can be done with distance settings (delay) or often just with phase settings. In a two sub system, one sub would be at zero distance/delay/phase, and then the other sub you would step through distance options (or phase) incrementally, measuring each time, until you see the greatest summation of output with the fewest dips. At that point, the subs are aligned with one another. There are at two popular tools for this: 1) using the phase knob on one sub; 2) using an external DSP like a miniDSP. Using the distance setting on the AVR even if it allows addressing one sub at a time is problematic because more room EQ systems will override what you do here (and you have to do it BEFORE running room EQ not after).
2. Time align the collective "sub" (really many subs acting as one) with the mains. This is where you adjust both distance (delay) and the crossover frequency. Distance is usually adjusted in the AVR, a single value for the "sub" (group of subs that are playing in mono, and are already time aligned with one another) though it can be done in an external device like a miniDSP, as well. This is an iterative process, trying different distances until you find the one with the best linear response or at least fewest dips, in the crossover region. It gets a little complicated because you will ALSO do an iterative process to find the best crossover frequency, starting perhaps at 50hz and trying every 5 ish hertz up to 140. Chances are good some crossover points will result in the fewest dips. But the complexity is that these two variables (delay for the "sub", and crossover frequency) can interact a bit, so when you dial in one ideally, and then the other, the first one may need to be adjusted, and so on, until the best COMBINATION is found.