Optimizing subwoofers and integration with mains: multi sub optimizer - Page 25 - AVS Forum | Home Theater Discussions And Reviews
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post #721 of 777 Old 07-16-2017, 02:41 PM
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Originally Posted by andyc56 View Post
I'm not sure exactly what you did, but you want to use the REW biquad file import feature as described on page 31 of the 10x10 manual ("Parametric EQ advanced mode" and "Parametric EQ file import (REW integration)").


That's by design, to prevent convergence problems in the optimizer. Typically, you'll have no delay block in the channel that's associated with the sub that's most distant from the MLP, and delay blocks in all the others.
I used the MSO "save biquad text for this channel" in the right-click menu of "filters" on each channel after I ran the Optimizer. I then imported these .txt files into the MiniDSP PEQ banks of corresponding channels.

I did have it configured for 48Khz - Now in MiniDSP it shows 6 biquad PEQ bands, and the first 4 have data (I guess corresponding to the 4 PEQ filters I had in MSO / channel) and the curves look like they do in MSO So I guess if I added more than 6 PEQ filters in MSO I'd get an error trying to import the MSO generated biquad .txt file into the MiniDSP so I'll definitely change 10 to 6 in the hardware pane.

Thanks for clarification on the number of delay filters - don't remember seeing that anywhere so good to know. So is it max of 5, or farthest one (how does it know this?) will not accept delay filter?

I also noticed a delay value was outside the 15ms max I specified, but assume it is because I clicked "normalize delays" and "Normalize gain" on all sub channels. I don't think the MiniDSP will take a negative value?

Also, I think one sub channel may have been originally measured with the polarity reversed. Will I need to re-measure, or can I put a Polarity Reverse filter on that channel and re-optimize?

I'll need to look at REW to actually test all channels with it for polarity - not sure how this is done in REW. Normally I feel I can do it by ear, but I'll read up on REW a bit more.

Thanks!

Last edited by Iamjcl; 07-16-2017 at 02:48 PM.
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post #722 of 777 Old 07-16-2017, 03:11 PM
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Originally Posted by Iamjcl View Post
I used the MSO "save biquad text for this channel" in the right-click menu of "filters" on each channel after I ran the Optimizer. I then imported these .txt files into the MiniDSP PEQ banks of corresponding channels.

I did have it configured for 48Khz - Now in MiniDSP it shows 6 biquad PEQ bands, and the first 4 have data (I guess corresponding to the 4 PEQ filters I had in MSO / channel) and the curves look like they do in MSO So I guess if I added more than 6 PEQ filters in MSO I'd get an error trying to import the MSO generated biquad .txt file into the MiniDSP so I'll definitely change 10 to 6 in the hardware pane.
Just to double-check, it might be good to have a look at the text file in a text editor, then compare its contents with the UI of the miniDSP plugin to make sure they match.

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Thanks for clarification on the number of delay filters - don't remember seeing that anywhere so good to know. So is it max of 5, or farthest one (how does it know this?) will not accept delay filter?
It doesn't know this, so the user is responsible for making it happen.

For "sub+main" configurations, the limitations are as shown in "Adding Filters, Delays and Gains". Unfortunately, when I added "sub-only" configurations, which came later, I didn't update that page. So I'll need to fix those docs.

The rules for "sub-only" configurations are:
  1. No shared delays allowed
  2. For a system with N sub channels, only N-1 delays are allowed

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I also noticed a delay value was outside the 15ms max I specified, but assume it is because I clicked "normalize delays" and "Normalize gain" on all sub channels. I don't think the MiniDSP will take a negative value?
A negative delay in the literal sense is a predictor. I need one of those for stock market investing. But seriously, negative delays only make sense in the context of a shared delay, in which case it means "increase the sub distance setting from what it was when the measurement was performed" (thereby reducing what the sub delay was).

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Also, I think one sub channel may have been originally measured with the polarity reversed. Will I need to re-measure, or can I put a Polarity Reverse filter on that channel and re-optimize?
Yes, that will work.

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I'll need to look at REW to actually test all channels with it for polarity - not sure how this is done in REW. Normally I feel I can do it by ear, but I'll read up on REW a bit more.
Look at the impulse response, with the vertical axis displayed in percent. It will be asymmetric, with a big "blip" in one direction, either positive or negative. If all subs have the big blip in the same direction, they're all of the same polarity. If there's a mix, some have reversed polarity and some do not.

Just to double-check, you did use an acoustic timing reference in REW, right? You should hear a high-frequency sweep coming out of the acoustic timing reference speaker on each measurement.
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post #723 of 777 Old 07-16-2017, 03:13 PM
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Results of MSO Best Flat and Dirac

Graphed the results at 3 locations and averaged them out. Hope I'm listening to the average

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post #724 of 777 Old 07-16-2017, 05:04 PM
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Originally Posted by andyc56 View Post
Look at the impulse response, with the vertical axis displayed in percent. It will be asymmetric, with a big "blip" in one direction, either positive or negative. If all subs have the big blip in the same direction, they're all of the same polarity. If there's a mix, some have reversed polarity and some do not.

Just to double-check, you did use an acoustic timing reference in REW, right? You should hear a high-frequency sweep coming out of the acoustic timing reference speaker on each measurement.
Yes - I did take the measurements that way. I'll go back and look at the impulse graphs.

I had some subs purposely reversed as it sounded clearly "wrong" when they weren't reversed. I'm sure it was probably "right" at some frequencies and some seats, but the two I had reversed definitely sounded better that way when playing with all the others (this with no EQ or other manipulation). If I didn't reverse them they canceled out much of what the others were doing (at least at the seating locations).

This said, REW impulse response I guess will show me which ones were reversed, but does that mean it was set correctly in the context of the other subs? I guess what I'm saying is what's the best way to initially determine 0 or 180 phase on each of the 6 subs? Should I leave them all at 0 and just let MSO do its thing?

EDIT: Just checked the graphs as you suggested and they all show blips extending to the right but I'm sure 2 of the subs were reversed. Is this possible? Is REW impulse graph showing some kind of relative phase or absolute?

Not sure I have a good handle on this.

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post #725 of 777 Old 07-16-2017, 05:37 PM
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Originally Posted by andyc56 View Post
You'll need to remove the stuff at the bottom, starting with HPSLOPEON. The function for reading the file looks at each line to see if it begins with a number (or + sign, - sign etc.) and if it does not, it's considered a comment line and ignored. The stuff at the bottom of the file has lines containing a single number, so that will mess it up, as it will interpret those lines as a frequency value with a missing dB value. So each line should either begin with non-numeric data, or if it is numeric data, it must be a frequency / dB value pair. Leading white space is ignored in any case.
Thx. Worked like a charm. Was able to import the file no problem. Also included the curve graph. It only shows the imported curve. Would be great to see positions with Curve to see how it adapted the curve.

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I'm not sure what you mean by "100% phase aligned". If you're referring to the technique in AustinJerry's guide that determines delays from the difference in distance to the MLP of the most distant sub and each other one under consideration, that calculation implicitly assumes that the relative phase difference vs. frequency due to this distance difference is determined only by the distance itself. But this is only true in an anechoic environment. In a modal regime, the same physical phenomena that mess up the amplitude responses of subs also affects their phase response. That may be the reason the calculated delays using that technique differ from what MSO comes up with. If you're worried about time domain performance, my suggestion is to not deviate too far from the delays calculated from distance, but I don't have a solid mathematical justification for that. Optimizing time domain performance would require something like what Markus suggested earlier, involving optimization of the excess group delay in addition to response flatness. That would involve huge changes, but I'm still considering it for some later time.
[/Quote]

I didn't follow Jerry's guide. I basically put the mic at MLP and took each sub reading wit Time reference included in REW. Then saw how they are aligned in Phase graph. I have four subs. Two in the front and in the back. I had to invert the front subs to make them phase align with front and also had to add 4ms delay to the back subs to have all the phase arrive at MLP at the same time. Then I took all the readings for MSO. Then in MSO I added delay with a constrain of Min=-3 and Max=3 and let it run. Finally, I subtracted the given delay from original ones that I had used to aligned them properly before Running MSO.
Here is how it went
Before MSO
Ch 1 = 4ms
Ch 2 = 4ms
Ch 3 = 0
Ch 4 = 0
Ran MSO and mso set delays as
Ch 1 = -3.95ms
Ch 2 = -2.92 ms
Ch 3 = 1.87
Ch 4 = 0 ms

So I finally ended up setting the delays as
Ch 1 = 4-3.95 = .05ms
Ch 2 = 4-3.92 = .08ms
Ch 3 = 0+1.87 = 1.87ms
Ch 4 = 0 = 0ms

Is this not the right approach? Or I should just simply set the phases properly (front subs inverted) and don't bother about aligning the phases (no delay set in minidsp2x4 and let MSO decide what delays should be assigned?
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post #726 of 777 Old 07-17-2017, 06:55 AM
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Thx. Worked like a charm. Was able to import the file no problem. Also included the curve graph. It only shows the imported curve. Would be great to see positions with Curve to see how it adapted the curve.
Huh? A target curve is just that, no more and no less. If you want your frequency response to match the target curve, you'll need to add a filter that allows that to happen, such as a variable Q LF shelf in the shared sub filters, then run an optimization. If you were to do such a thing, and you had already run an optimization for flat response, you would lock all parameters of all the individual channel filters, as these would have already been optimized to minimize seat-to-seat response variation. Then the optimization would only vary the Q and corner frequency of the shared LF shelf filter to get what you want.

More importantly, if you're using Dirac, you should use its target curve feature to get what you want, not MSO. Dirac has much more sophisticated filtering than simple biquads, and is much more capable of matching the desired curve.

Regarding the polarity/delay procedure, it looks like it would work in theory. But if all your subs, sub settings and sub amplifiers are the same, and there were no per-channel polarity inversions in the miniDSP box at the time the measurements were performed, and you have determined that some subs should have an inversion applied to them and some not, then something is wrong.
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post #727 of 777 Old 07-17-2017, 06:59 AM
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I am ending support for MSO in this thread for now.

Edit: Status of MSO Support

Last edited by andyc56; 07-18-2017 at 04:06 PM.
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post #728 of 777 Old 07-17-2017, 07:51 AM
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I am ending support for MSO in this thread for now.
Sorry to hear that. Thanks for getting me up and running, I'll def continue playing with it. Will you be posting software updates here?
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post #729 of 777 Old 07-17-2017, 07:59 AM
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Originally Posted by andyc56 View Post
Huh? A target curve is just that, no more and no less. If you want your frequency response to match the target curve, you'll need to add a filter that allows that to happen, such as a variable Q LF shelf in the shared sub filters, then run an optimization. If you were to do such a thing, and you had already run an optimization for flat response, you would lock all parameters of all the individual channel filters, as these would have already been optimized to minimize seat-to-seat response variation. Then the optimization would only vary the Q and corner frequency of the shared LF shelf filter to get what you want.

More importantly, if you're using Dirac, you should use its target curve feature to get what you want, not MSO. Dirac has much more sophisticated filtering than simple biquads, and is much more capable of matching the desired curve.
I use a custom house curve in Dirac that goes 10dB down by 200Hz. Therefore I thought what's the point to have MSO flat out FR at frequencies that will need to be cut. Like around say 120Hz. If MSO flattens it out by applying a gain of say 8dB and then later Dirac cuts it to match the custom curve then that gain from MSO wasn't necessary. Therefore, If I give MSO the curve that Dirac will also work on, it will get the FR that much closer for Dirac to work on. I'm not going to skip Dirac. Just wanted the FR to look closer to what Dirac will work with. After importing the curve, when I ran MSO, it did start matching the FR. It worked

Quote:
Regarding the polarity/delay procedure, it looks like it would work in theory. But if all your subs, sub settings and sub amplifiers are the same, and there were no per-channel polarity inversions in the miniDSP box at the time the measurements were performed, and you have determined that some subs should have an inversion applied to them and some not, then something is wrong.
All my subs are sealed but not from same company. In fact, two are dual opposing and 4 are with 1 driver. They all have 18" drivers though. I found out the polarity wasn't aligned (reversed) before taking reading and inverted where needed in minidsp even before I took reading in REW for MSO. For the time being to keep things simple, I took out the Delay filter from configuration. I am still getting very good results. Will have to upload the filters and see how it sounds. Will update.
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post #730 of 777 Old 07-17-2017, 09:25 AM
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I am ending support for MSO in this thread for now.
Thanks for your time!

I wish I had found MSO earlier as I still feel like I'm a bit in the dark - hopefully others here can help us newcomers.
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post #731 of 777 Old 07-17-2017, 10:39 AM
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@andyc56

I hope you are able to spend a bit more time on your personal projects - and that in future you are able to return to MSO reinvigorated.
If I can, I will try to assist new users - but obviously I do not have the in depth knowledge of MSO's inner workings - but I have used it successfully many times, and will continue to use it when equipment or room changes occur.
Best regards andy - Mike.
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post #732 of 777 Old 07-17-2017, 11:18 AM
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@andyc56

I hope you are able to spend a bit more time on your personal projects - and that in future you are able to return to MSO reinvigorated.
If I can, I will try to assist new users - but obviously I do not have the in depth knowledge of MSO's inner workings - but I have used it successfully many times, and will continue to use it when equipment or room changes occur.
Best regards andy - Mike.
Thanks for considering assisting us less-proficient (but no-less enthusiastic) users of MSO / REW.

What an incredible piece of software MSO is!

My daughter is quite proficient at advanced college level math (at a college known for its academic rigor) and she was intrigued (and more than a little impressed!) by the challenges MSO takes on.

I am however not a math guy, but can certainly appreciate the complex undertaking of MSO. Would be like solving a 16.5 sided Rubik's cube to me...
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post #733 of 777 Old 07-18-2017, 12:15 PM
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A few very general MSO questions:


1) If you finish an optimization, reload it later and click "optimize", is it the same as running the original optimization for a longer amount of time (optimizing an already optimized configuration - any reason not to?)?

2) MSO has generated some pretty awesome looking graphs for me. I've only programmed into the MiniDSP and listened to 2 of them, but there is clearly an "unnatural" sound to it at times (though certain aspects sound great as well). I'm guessing it is all the EQ, and maybe very selective / narrow bands of it? Don't know, but is there an approach that can yield more natural sounding results at the expense of less-flat graphs? Haven't listened to enough to make any real judgement here at all - just a suspicion at this point. The "no seats sound clearly bad" results are excellent from MSO in my (very, very) limited time with it.
I've run an Optim or two with the weighting down to .2 on the less important seats, but would deleting those seating positions from the config altogether be a better way to avoid excessive EQ that might taint the "naturalness" of the MLP (but while still flattening it's FR graph)?

3) Related to the above, but would assigning 6 PEQ filters / channel be excessive and contribute to the above - or would that just allow MSO more flexibility to do what it needs to do? More PEQs / channel and less gain/boost for each or less PEQs / channel w/ more gain / cut latitude?

4) Lastly - I realized I took a set of measurements (sub only config) with the AVR distance settings of: L, R (my REW timing Ref.)=18' and Sub=32'. I gather from all the reading here that I should be using 1' (lowest I can select) for L,R, and SUB. But It seems to me that MSO is dealing with a relative time difference between all the Subs (which all have the same AVR delay built in) and the L/R timing reference (which has a different AVR delay built in). So I'm not sure it matters since MSO is only providing me with delay values for each sub (I guess which is relative among them) and not the main channels. Do I need to re-measure the subs with the AVR distance changed? Will it matter? I also left off the delay channel of one sub which is the farthest from MLP. Andy noted that MSO won't let you add a delay channel for all subs - 1 must be left off. So I assume this was the correct way to do this? I do realize I need to change the AVR distance values after measuring (for actual use) to something that attempts to time align the satellites with the collective sub grouping.

Thanks to anybody who knows and has a few minutes to explain what I'm doing wrong.
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post #734 of 777 Old 07-18-2017, 01:04 PM
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@Iamjcl I wish I could help you out but I'm left hanging here too. As far as question 2 take a look at this http://andyc.diy-audio-engineering.o...#improving_mlp it'll let you take an optimized config and fine tune it to the MLP. I did it and the graph looks a little better at the MLP but haven't tested it yet.

re: the unnatural sound, I had a similar feeling (still kinda do, hoping it's me lol ) but Dirac balanced things out nicely. That being said, the waterfall in REW and my ears say there's a lot of ringing and I'm not sure how to fix that.
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post #735 of 777 Old 07-18-2017, 04:33 PM
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@Iamjcl I wish I could help you out but I'm left hanging here too. As far as question 2 take a look at this http://andyc.diy-audio-engineering.o...#improving_mlp it'll let you take an optimized config and fine tune it to the MLP. I did it and the graph looks a little better at the MLP but haven't tested it yet.

re: the unnatural sound, I had a similar feeling (still kinda do, hoping it's me lol ) but Dirac balanced things out nicely. That being said, the waterfall in REW and my ears say there's a lot of ringing and I'm not sure how to fix that.
Thanks - I'd forgotten about that part of the tutorial. Lots to read and lots to remember. I've got a lengthy Word document with my notes on all the different programs, procedures, imports, exports, file types, measurements, settings....
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post #736 of 777 Old 07-19-2017, 07:10 AM
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@andyc56

I hope you are able to spend a bit more time on your personal projects - and that in future you are able to return to MSO reinvigorated.
If I can, I will try to assist new users - but obviously I do not have the in depth knowledge of MSO's inner workings - but I have used it successfully many times, and will continue to use it when equipment or room changes occur.
Best regards andy - Mike.
Hoping you might have a minute to comment on the very basic questions above, as well as one more here? If so that would be helpful. Thank you, or thanks to anyone else who knows!

When performing a sub-only config (don't want to include Mains in MSO or MiniDSP) - 6 subs in this case - I've been routing signals like this:

AVR - L,C,R,+surround pre-outs --> Respective amp channel inputs

AVR - Sub pre-out --> MiniDSP --> Respective Sub amp channel inputs

So regarding timing (I have REW outputting the timing reference via HDMI on Left or Right channel (does not go through MiniDSP) and the sub out going through MiniDSP and outputting x6. It seems to me that the MiniDSP would have to introduce additional delay to the subs. But, all should have same amount of delay added I presume, so relative to each other they have the same delay "offset" from the timing reference I would guess?

I say this because I could save some time if none of this matters and I don't have to re-measure, and future measurements wouldn't involve temporary re-cabling.

So while I'll attempt the AVR / Sub group time alignment AFTER MSO (and in the AVR), I wonder if for the initial measurements there is any benefit to routing like this instead (and then after taking the measurements, connecting back like the above, which is how I would actually use the setup):

AVR - R pre out --> MiniDSP --> R amp channel input * for REW timing reference

AVR - Sub pre out --> MiniDSP --> Respective Sub amp channel inputs

And further, I'm not sure the above would be 100% since I have all the PEQ / Delays / Gains / etc... disabled or set to 0 in MiniDSP for the REW measurements - engaging some or all of these (which MSO of course will require) might add to the actual delays??? Very confusing, but maybe I'm also over thinking it.

Thanks!

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Originally Posted by Iamjcl View Post
Hoping you might have a minute to comment on the very basic questions above, as well as one more here? If so that would be helpful. Thank you, or thanks to anyone else who knows!

When performing a sub-only config (don't want to include Mains in MSO or MiniDSP) - 6 subs in this case - I've been routing signals like this:

AVR - L,C,R,+surround pre-outs --> Respective amp channel inputs

AVR - Sub pre-out --> MiniDSP --> Respective Sub amp channel inputs

So regarding timing (I have REW outputting the timing reference via HDMI on Left or Right channel (does not go through MiniDSP) and the sub out going through MiniDSP and outputting x6. It seems to me that the MiniDSP would have to introduce additional delay to the subs. But, all should have same amount of delay added I presume, so relative to each other they have the same delay "offset" from the timing reference I would guess?

I say this because I could save some time if none of this matters and I don't have to re-measure, and future measurements wouldn't involve temporary re-cabling.

So while I'll attempt the AVR / Sub group time alignment AFTER MSO (and in the AVR), I wonder if for the initial measurements there is any benefit to routing like this instead (and then after taking the measurements, connecting back like the above, which is how I would actually use the setup):

AVR - R pre out --> MiniDSP --> R amp channel input * for REW timing reference

AVR - Sub pre out --> MiniDSP --> Respective Sub amp channel inputs

And further, I'm not sure the above would be 100% since I have all the PEQ / Delays / Gains / etc... disabled or set to 0 in MiniDSP for the REW measurements - engaging some or all of these (which MSO of course will require) might add to the actual delays??? Very confusing, but maybe I'm also over thinking it.

Thanks!
Okay, this one should be fairly easy (famous last words) - you can use any of your main channels for the acoustic timing reference (in fact it must be speaker with good high frequency output) - and any added delay due to the miniDSP in the sub chain will not matter at all - as you said yourself, the delay will be present on all the outputs. The timing reference does not have to be an absolute reference - it is a relative reference, and only the differences between the sub channels are important when doing sub-only configurations. So stick with your current connection configuration.
Regards, Mike.
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post #738 of 777 Old 07-19-2017, 10:35 AM
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Okay, this one should be fairly easy (famous last words) - you can use any of your main channels for the acoustic timing reference (in fact it must be speaker with good high frequency output) - and any added delay due to the miniDSP in the sub chain will not matter at all - as you said yourself, the delay will be present on all the outputs. The timing reference does not have to be an absolute reference - it is a relative reference, and only the differences between the sub channels are important when doing sub-only configurations. So stick with your current connection configuration.
Regards, Mike.
Thank you!
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post #739 of 777 Old 07-21-2017, 06:31 AM
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Can someone please explain what "Shared Filter" is? When I normalize the gain of my optimization, it ends up creating a shared filter. Name suggests that the same value to be used for all the channels and instead of having this filter in all channel, its added in Shared and impacts all the channels.

I import all the filters in minidsp2x4. Do I need to take any extra steps besides exporting the channels from MSO when there is a shared filter?
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post #740 of 777 Old 07-21-2017, 06:58 AM
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Originally Posted by harrisu View Post
Can someone please explain what "Shared Filter" is? When I normalize the gain of my optimization, it ends up creating a shared filter. Name suggests that the same value to be used for all the channels and instead of having this filter in all channel, its added in Shared and impacts all the channels.

I import all the filters in minidsp2x4. Do I need to take any extra steps besides exporting the channels from MSO when there is a shared filter?
http://andyc.diy-audio-engineering.o...#improving_mlp

Markus

"In science, contrary evidence causes one to question a theory. In religion, contrary evidence causes one to question the evidence." - Floyd Toole
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post #741 of 777 Old 07-21-2017, 07:00 AM
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thx. Wooww what a coincident. I was composing a question for you and here you are.

a question related to subs phase + MSO. So after you mentioned that Sub FR is only half of the story and the sub time alignment is also a major part, I took readings of each sub with timing reference and then overlayed them in Impulse response all at MLP. Subs were not properly aligned. 2 subs were out of phase. So reversed their polarity (minidsp2x4) and also added proper delays till all of the subs were properly aligned in Impulse response. So far so good. Now in MSO, since I already have aligned all the delays (only at MLP thought), is it still better to include the Delays for each channel? The fact that I aligned the subs only at MLP, most likely they are off at another position.
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post #742 of 777 Old 07-21-2017, 07:42 AM
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Originally Posted by harrisu View Post
thx. Wooww what a coincident. I was composing a question for you and here you are.

a question related to subs phase + MSO. So after you mentioned that Sub FR is only half of the story and the sub time alignment is also a major part, I took readings of each sub with timing reference and then overlayed them in Impulse response all at MLP. Subs were not properly aligned. 2 subs were out of phase. So reversed their polarity (minidsp2x4) and also added proper delays till all of the subs were properly aligned in Impulse response. So far so good. Now in MSO, since I already have aligned all the delays (only at MLP thought), is it still better to include the Delays for each channel? The fact that I aligned the subs only at MLP, most likely they are off at another position.
That's not how it works. Aligning the impulse response peak is just a starting point. Having subs polarity inverted and delayed can actually give a better response in the frequency domain AND the time domain. Look at the excess phase group delay which reveals non-minimum phase areas. The goal is to have a smooth frequency response AND low excess group delay.
Please see https://www.roomeqwizard.com/help/he...imumphase.html

Markus

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post #743 of 777 Old 07-21-2017, 01:16 PM
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That's not how it works. Aligning the impulse response peak is just a starting point. Having subs polarity inverted and delayed can actually give a better response in the frequency domain AND the time domain. Look at the excess phase group delay which reveals non-minimum phase areas. The goal is to have a smooth frequency response AND low excess group delay.
Please see https://www.roomeqwizard.com/help/he...imumphase.html
Thx. Read the page a few times to get the most I could. Also read your post here Simplified REW Setup and Use (USB Mic & HDMI Connection) Including Measurement Techniques and How To Interpret Graphs which helped me understand it more. In GD (group Delay) screen, when I graph and compare with minimum phase, I didn't find anywhere anything that can't be eqed. I'll upload the file when I get you. Would appreciate if you can take a look.

So assuming that the group delay looks fine, what should we do with MSO with delay filter? Should it still be added to each channel and let MSO come up with delay? I know that MSO is not geared to fix phases but I took care of that already.
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post #744 of 777 Old 07-22-2017, 12:23 AM
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Whichever gives you the best result. Compare frequency response and excess group delay.

Markus

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post #745 of 777 Old 07-29-2017, 09:49 AM
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Need Help: Low frequency response of Xilica XP-4080

I need some help from the experts. Anyone using Xilica XP-2040 or 4080 to allow for delay, EQ, level adjustments for multiple subs? I currently have 4 subs (two JTR and two Seaton) that I will need to manage since my surround processor only has two sub outs (I may be buying two more JTR S1 in the near future).

The manual states frequency response only goes down to 20Hz but I am not sure if that just means that it can only EQ frequencies 20Hz and above or if it means it will cut off frequencies below 20Hz? Obviously I don't want any low frequency to be cut off.

Datasat LS10 with Atmos / DTS X and Dirac Live cards __ Parasound Halo A31, Parasound Zonemaster 1250 bridged, Parasound Zonemaster 450 bridged
Procella P8 LCR, Procella P5iw and P5v for surround/Atmos speakers __ JTR Captivator S2 front-center, Dual Seaton Submersive on side walls, JTR Captivator S1 center-rear
Screen: 2.40:1 Seymour XD, 128" diagonal / 118" wide __ Projector: JVC 4910
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post #746 of 777 Old 07-29-2017, 10:49 AM
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Farsider3000 - Unfortunately, this is normal for consumer electronics as most companies are just lazy and use the age-old tradition of 20-20,000Hz for their electronics. Most audio devices do not roll off until much lower than 20 Hz, usually under 10 Hz but it depends on the device. The only way to know for sure is to measure the device to see how low the signal goes. The Xilica is a nice DSP and even cheaper DSPs such as MiniDSP don't roll off until much lower than 10 Hz. And I've measured my 24s in many rooms with quite varied audio equipment and in all cases, the subs output was flat until 7 Hz and in one room where the sub was corner loaded, it was flat until 6 Hz. In almost all cases the audio equipment stated 20-20000 Hz but obviously that is not accurate if the subs have output below 10 Hz. So I wouldn't necessarily be concerned that the Xilica states 20-20000 Hz, your other equipment likely states similarly.

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post #747 of 777 Old 07-30-2017, 01:47 AM
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The manual states frequency response only goes down to 20Hz but I am not sure if that just means that it can only EQ frequencies 20Hz and above or if it means it will cut off frequencies below 20Hz? Obviously I don't want any low frequency to be cut off.
Frequency response specs have two parts, a frequency range and a flatness over that range. In the case of the XP series the spec is +/- 0.1dB (20 to 30kHz), within that 20 Hz to 30 kHz range the response is flat to within a tenth of a dB. It will (eventually) roll off outside that, but you needn't have any concern at all about the XP not passing through your content.
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post #748 of 777 Old 07-30-2017, 06:52 AM
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Farsider3000 - Unfortunately, this is normal for consumer electronics as most companies are just lazy and use the age-old tradition of 20-20,000Hz for their electronics. Most audio devices do not roll off until much lower than 20 Hz, usually under 10 Hz but it depends on the device. The only way to know for sure is to measure the device to see how low the signal goes. The Xilica is a nice DSP and even cheaper DSPs such as MiniDSP don't roll off until much lower than 10 Hz. And I've measured my 24s in many rooms with quite varied audio equipment and in all cases, the subs output was flat until 7 Hz and in one room where the sub was corner loaded, it was flat until 6 Hz. In almost all cases the audio equipment stated 20-20000 Hz but obviously that is not accurate if the subs have output below 10 Hz. So I wouldn't necessarily be concerned that the Xilica states 20-20000 Hz, your other equipment likely states similarly.
David thank you so much for providing this feedback. I am so glad we have knowledgable pros like you on AVS to provide this knowledge to end users. ! I am impressed by your subs and have followed a few blogs that used your products.

Datasat LS10 with Atmos / DTS X and Dirac Live cards __ Parasound Halo A31, Parasound Zonemaster 1250 bridged, Parasound Zonemaster 450 bridged
Procella P8 LCR, Procella P5iw and P5v for surround/Atmos speakers __ JTR Captivator S2 front-center, Dual Seaton Submersive on side walls, JTR Captivator S1 center-rear
Screen: 2.40:1 Seymour XD, 128" diagonal / 118" wide __ Projector: JVC 4910
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post #749 of 777 Old 07-30-2017, 06:56 AM
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Frequency response specs have two parts, a frequency range and a flatness over that range. In the case of the XP series the spec is +/- 0.1dB (20 to 30kHz), within that 20 Hz to 30 kHz range the response is flat to within a tenth of a dB. It will (eventually) roll off outside that, but you needn't have any concern at all about the XP not passing through your content.
Thank you for this information. It's really cool that we have input from all over the world! We will be using the XP-4080 to help control my four subs since my Datasat only has two independent sub outputs. My acoustic engineer will be performing the EQ and Dirac calibration soon.

Datasat LS10 with Atmos / DTS X and Dirac Live cards __ Parasound Halo A31, Parasound Zonemaster 1250 bridged, Parasound Zonemaster 450 bridged
Procella P8 LCR, Procella P5iw and P5v for surround/Atmos speakers __ JTR Captivator S2 front-center, Dual Seaton Submersive on side walls, JTR Captivator S1 center-rear
Screen: 2.40:1 Seymour XD, 128" diagonal / 118" wide __ Projector: JVC 4910
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post #750 of 777 Old 08-09-2017, 03:04 PM
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Does anybody know how to generate a "target curve" for import into MSO?

Thanks
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