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Author Topic: Channel Delay in Room Correction Faulty  (Read 1311 times)

carlismysecondname

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Channel Delay in Room Correction Faulty
« on: October 15, 2019, 12:29:26 am »

Hi. I've been playing around with the delays and volume adjustments for the left and right channels in JRiver's Room Correction.

Moving a channel's slider delay from 0.03 to 0.04 almost completely mutes the channel. As you increase the delay the volume SLOWLY comes back up in that channel -- but doesn't seem to go back to the original volume until way up, say around 70+ m (meters?).

*Same behaviour with 5.1 channels. If you move the slider by a lot, the DSP starts to glitch. After resetting the volume goes back to normal. again, moving the slider past 0.03 almost mutes the channel's volume -- so once the glitch happens, it stays glitchy even after resetting and increasing delay slowly back again. Set delays to, say 4 meters, but then completely restart JRiver: volume goes back to normal.


---

Another weird behaviour(s) -- although tell me if this is normal when upmixing Stereo to 5.1 MCH (surrounds and fronts)-- is if the Bass Management 'Crossover' is is set to 'no crossover' (from having a crossover), the volume is suddenly, significantly lowered. Setting the crossover to 40-up will increases the volume to normal back again. Can't test all situations as I only use four channels + a sub.

*output is 5.1 channels.

**This glitch happens esp. when switching between crossovers several times. After setting both surrounds and fronts to finally 'no crossover' and then restarting, the volume still remains low. When you enable a crossover the volume just suddenly jumps back up again.

***It's easier to replicate when you switch the crossovers around ALL left, right and surround channels -- rather than just the main left and right channels alone. SET ALL crossovers to no crossovers. The volume will become lower. Uncheck the Room Correction DSP and volume jumps back up. For whatever reason, sometimes when you restart and still enable Room Correction with no crossovers, volume is boosted to max again. ANYHOW, I use miniDSP so I can bypass all this nonesense altogether. I just want to point out these peculiar inconsistencies in the way JRiver's Room Correction DSP behaves.
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Matt

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Re: Channel Delay in Room Correction Faulty
« Reply #1 on: October 15, 2019, 08:20:00 am »

The distance to speakers is used to set the relative volume levels.  If one speaker is close (0.1 ft) and another is a long ways away (10 ft), it's going to morph the volume by a lot to compensate.  You can then calibrate with a decibel meter and adjust the "Volume level" slider to make fine adjustments.
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Matt Ashland, JRiver Media Center

kr4

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Re: Channel Delay in Room Correction Faulty
« Reply #2 on: October 15, 2019, 09:09:38 am »

The distance to speakers is used to set the relative volume levels.
That is not correct.  The sound should be delayed in time by this setting.  Adjustment of volume level should only be via the volume slider. 
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Kal Rubinson
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Matt

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Re: Channel Delay in Room Correction Faulty
« Reply #3 on: October 15, 2019, 09:13:30 am »

That is not correct.  The sound should be delayed in time by this setting.  Adjustment of volume level should only be via the volume slider.

It adjusts both the volume and the timing.  You can adjust the volume by hand as well.
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Matt Ashland, JRiver Media Center

kr4

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Re: Channel Delay in Room Correction Faulty
« Reply #4 on: October 15, 2019, 10:48:13 am »

It adjusts both the volume and the timing.  You can adjust the volume by hand as well.
It does?  Perhaps that is why I have have not been happy with it and never used it.  By its name, it should adjust for distance (timing) only, as is the general practice in the industry.

1) Is this made clear somewhere? 
2) is it possible to confine its operation to only the time domain?
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Kal Rubinson
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Matt

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Re: Channel Delay in Room Correction Faulty
« Reply #5 on: October 15, 2019, 10:57:51 am »

It does?  Perhaps that is why I have have not been happy with it and never used it.  By its name, it should adjust for distance (timing) only, as is the general practice in the industry.

1) Is this made clear somewhere? 
2) is it possible to confine its operation to only the time domain?

If we know the distance of two matched speakers, we know the volume difference from that distance.  Accounting for it is valid.

Calibrating with a decibel meter is something you should do if you're serious about your system.  We have the tools to make it pretty simple.  I've done my system lots of times and even my parents system.
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Matt Ashland, JRiver Media Center

mattkhan

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Re: Channel Delay in Room Correction Faulty
« Reply #6 on: October 15, 2019, 11:20:11 am »

What adjustment do you make? Power law based?
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dtc

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Re: Channel Delay in Room Correction Faulty
« Reply #7 on: October 15, 2019, 02:22:10 pm »

In Room Correction, Distance is clearly associated with timing and Volume Level is a separate Option.  In keeping with the rest of the industry, I would expect them to be distinct.  If Volume adjusts are included under Distance they should be a distinct option, not just included.
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kr4

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Re: Channel Delay in Room Correction Faulty
« Reply #8 on: October 15, 2019, 03:55:41 pm »

If we know the distance of two matched speakers, we know the volume difference from that distance.  Accounting for it is valid.

Calibrating with a decibel meter is something you should do if you're serious about your system.  We have the tools to make it pretty simple.  I've done my system lots of times and even my parents system.
Calibrating with measurement at the listening position is always necessary since it also accounts for angular orientation, local reflections, etc.
As others have stated, having completely independent adjustments for time and level would be preferred.  The shortcut (which I had not know of before) only complicates things, i.e., if I measure and set level before setting distance, the result is wrong.
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Kal Rubinson
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carlismysecondname

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Re: Channel Delay in Room Correction Faulty
« Reply #9 on: October 26, 2019, 08:16:57 am »

Hmmmn. I may be naive here as I've never owned any AVR, but it doesn't sound good to me to have the delay settings touch another altogether separate variable i.e. volume. These should be completely separate. It is much easier to calibrate the SPL of each channel separately first, and then adjust time delay as necessary.

* I should note that the glitch I mentioned does not occur when doing only small incremental adjustments. It is when you are, for whatever reason, making huge jumps with the delay slider (the volume as well seems to change).
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