Optimizing subwoofers and integration with mains: multi sub optimizer - Page 61 - AVS Forum | Home Theater Discussions And Reviews
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post #1801 of 1830 Old 03-04-2020, 11:22 AM
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I am semi new to all of this, but I am definitely far down the rabbit hole and enjoying the process and learning!

Anyways, I am looking to integrating and using multiple sub-woofers and had a few questions. Specifically about REW, equalizer APO vs minidsp and multi sub optimizer.

My setup is 100% for listening to music and I am using my computer as the only source of music.

The setup is
Computer -> hdmi output -> receiver -> 2.2 or 2.3 setup.

I have a single sub output from my receiver so I was wondering do I need a mini dsp to equalize numerous subs or can I do other ingenious work arounds just using Equalizer APO.
I was wondering can I use the unused central and rear outputs of the 5.1 outputs to each go directly control each sub?
Can Equalizer APO do that (send the sub signal to various other channels)?
If so, any good guides online (as I have searched everywhere and not seen someone comment how to use equalizer apo to re direct the sub output to various other channels and then equalize them independently)?

I have 2 sealed subs and 1 ported.... And my understanding is that they should not mix. Just stick with all ported or all sealed correct?

Any thoughts about the current setup and ways to optimize it?

If this is not a possibility, are there any good ways to optimize and integrate multi subs without buying a minidsp?

Basically I am asking.... Do I need a mini dsp (or equivalent) for multiple subs or can I just use equalizer APO?

Thanks so much for any info! As I was going to get the umik-1 this week and making sure I don't need to order a minidsp also.

Thanks!
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post #1802 of 1830 Old 03-04-2020, 11:32 AM
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Welcome to the Forum!

miniDSP allows individual subs to have their own distance (and level) settings. Can't do that without a miniDSP, i.e. HARDWARE.

As this thread is for MSO, likely there are much better threads to ask your questions about sub types, etc.

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post #1803 of 1830 Old 03-04-2020, 12:11 PM
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Thanks for the quick reply!

I certainly see the utility of having a minidsp, I was just wondering if there was a way to rig ones computer to be the hardware to allow for a 2.2 setup.

I seem to recall that andyc56 was using Equalizer APO in a way similar to what I was describing and that a computer was enough hardware to change the unused outputs for numerous subs, but I have not been able to find any further details / guidance.
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post #1804 of 1830 Old 03-04-2020, 12:14 PM
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Well, you'd need to add specialized hardware to your computer to perform the processes. But I don't recall ever hearing about hardware like that.

Do you have multiple balanced audio outputs on your rig? Digital Signal Processors?

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post #1805 of 1830 Old 03-04-2020, 12:31 PM
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Originally Posted by pepar View Post
Well, you'd need to add specialized hardware to your computer to perform the processes. But I don't recall ever hearing about hardware like that.

Do you have multiple balanced audio outputs on your rig? Digital Signal Processors? [IMG class=inlineimg]/forum/images/smilies/smile.gif[/IMG]
You know a computer has a CPU? The calculations involved in applying some biquads to an audio stream are completely trivial so it is really a question about what software you use to do the job. There are many options here, best one depends on what you want to play.
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post #1806 of 1830 Old 03-04-2020, 12:31 PM
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Hummm. Not too sure. It is a pretty generic computer with no crazy sound card but it can output a 5.1 HDMI signal.

I guess I have not played around with Equalizer APO enough to know if it can do everything I am potentially asking of it (but somehow I do have hope that it can substitute for a mini dsp if only wanting 4 outputs (R, L, sub 1, sub 2).
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post #1807 of 1830 Old 03-04-2020, 01:16 PM
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Originally Posted by 3ll3d00d View Post
You know a computer has a CPU? The calculations involved in applying some biquads to an audio stream are completely trivial so it is really a question about what software you use to do the job. There are many options here, best one depends on what you want to play.
Don't "duh?" me like that. You obviously missed my point. There are NO "options" that turn a PC into a substitute for a miniDSP.

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post #1808 of 1830 Old 03-04-2020, 01:19 PM
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Originally Posted by johnp98 View Post
Hummm. Not too sure. It is a pretty generic computer with no crazy sound card but it can output a 5.1 HDMI signal.
A soundcard can't introduce signal delays for time-aligning subs.

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post #1809 of 1830 Old 03-04-2020, 01:28 PM
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Originally Posted by pepar View Post
Don't "duh?" me like that. You obviously missed my point. There are NO "options" that turn a PC into a substitute for a miniDSP.
It is certainly possible to do that though I would be slightly surprised if that is what the poster actually needs.

The htpc forum might be a good place for the previous poster to get advice on this.
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post #1810 of 1830 Old 03-04-2020, 01:48 PM
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Have IQ's fallen? A soundcard can't introduce signal delays for time-aligning subs. And, WTF, they are 5.1/7.1, not .3 or .4. Good grief.
I did not think it was that ridiculous of a question. I guess I am just assuming Equalizer APO can do a lot more than it actually can.
I was just thinking that if the signal is 5.1 could I not use those 5 speaker outputs do drive 2 main L and R speakers and then modify and alter the other 3 channels for 3 subs (connected via speaker wire, rather than the .1 sub output).

It sounds like that is just a pipe dream and not a possibility... but somehow it does not seem too difficult to me.
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post #1811 of 1830 Old 03-04-2020, 02:53 PM
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Originally Posted by johnp98 View Post
I seem to recall that andyc56 was using Equalizer APO in a way similar to what I was describing and that a computer was enough hardware to change the unused outputs for numerous subs, but I have not been able to find any further details / guidance.
That's correct. Have a look at the Equalizer APO "copy" command. It can, for example, be used to route 0.5*L + 0.5*R to, say, each of the 4 unused surround channels of a 7.1 AVR, which could then be used for the subs. For this to work, the L, R and surrounds would all be set to "large" in the AVR (which needs to have preamp outs). Then, using Equalizer APO, you'd put high-pass LR4 filters on the mains, and low-pass LR4 filters on the subs. It's "DIY bass management" as it were. Then finally PEQ per sub as necessary (or even on the mains too).

I'm doing this, not with an AVR, but with a Tascam US-16x08 followed by a Parasound P7, used as a MCH analog volume control.

Edit: Of course, this only works for two-channel users who are using multi-channel sound devices. In this case, the user is "stealing" the extra channels for use with the subs. It's not applicable to multi-channel systems.

Last edited by andyc56; 03-04-2020 at 03:48 PM.
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post #1812 of 1830 Old 03-04-2020, 05:36 PM
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Originally Posted by andyc56 View Post
That's correct. Have a look at the Equalizer APO "copy" command. It can, for example, be used to route 0.5*L + 0.5*R to, say, each of the 4 unused surround channels of a 7.1 AVR, which could then be used for the subs. For this to work, the L, R and surrounds would all be set to "large" in the AVR (which needs to have preamp outs). Then, using Equalizer APO, you'd put high-pass LR4 filters on the mains, and low-pass LR4 filters on the subs. It's "DIY bass management" as it were. Then finally PEQ per sub as necessary (or even on the mains too).

I'm doing this, not with an AVR, but with a Tascam US-16x08 followed by a Parasound P7, used as a MCH analog volume control.

Edit: Of course, this only works for two-channel users who are using multi-channel sound devices. In this case, the user is "stealing" the extra channels for use with the subs. It's not applicable to multi-channel systems.

Amazing! Thank you so much for the information! Ok I will just stick with ordering the umik-1 and see if I can use the setup that I already have.

Unfortunately I am not too sure if my AVR has pre-amp outs (I am 99% sure it does not have them). Would that put a kink in my proposed plans?
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post #1813 of 1830 Old 03-04-2020, 06:37 PM
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Originally Posted by johnp98 View Post
I am not too sure if my AVR has pre-amp outs (I am 99% sure it does not have them). Would that put a kink in my proposed plans?
For the technique to work, your AVR must have preamp outs for all channels (not just L and R as some have).
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post #1814 of 1830 Old 03-14-2020, 08:58 PM
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Originally Posted by Bayouslim77 View Post
Good morning everyone. I've been reading this thread and ok very interested in giving mso a try next week.i have an irregular shaped room that is partially open on one side which I've closed off with heavy acoustic blankets. They've made a noticeable difference sonically in my room as well as making my movie room very dark. My room is 20' long and midway along that length it widens to 15' then the narrows to 12'. Three seats sit center oF the room.i have the mini marty's sitting midwall at the front and rear walls. These subs are connected to a crown two channel amp. They minidsp 2x4 hd is connected to a Marantz sr8012 avr. I have two Klipsch 12" subs just laying around collecting dust and wanting to know if i should implement these subs into my system to give me Four subs or just use mso to better the response on the mini marty's? The smaller subs have BuIlt in amps at only 250 watts Plus phase knob and the crown amp pushes 1350 per channel.I'm thinking it would a mismatch. Any thoughts and advice? It's greatly Appreciated!
As far as your questions about acoustics go, it's assumed that if you decide to use MSO, you understand all the issues and have that all worked out. This thread is about how to use MSO to best advantage, given that you've worked out all the acoustic issues beforehand. This isn't a thread about acoustics.

Also, you are talking about a major mismatch between subs that have substantial output capability (Marty subs) and some commercial subs that can't keep up with them. That's not the realm of MSO either. MSO assumes your subs all have similar, if not identical output capability. If this condition does not hold, it's a non-trivial issue that's your responsibility to figure out how to deal with.
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Last edited by andyc56; 03-14-2020 at 09:12 PM.
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post #1815 of 1830 Old 03-15-2020, 05:56 AM
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In trying to get MSO and the Mini-DSP to work nicely with my AVR with mains integration as well, (i.e. not a sub-only configuration), I set just one filter for the mains at set it at 180Hz and with a minimal boost of 0.1dB and a very narrow range, and did not have a delay block. So when MSO optimised the response across my 3 subs AND the mains, I got a -ve common delay block for all 3 subs, then no delay on one sub and some delays on the other 2. For the -ve common delay block for all 3 subs, I increased the Sub distance in the Amp to correspond to the delay amount, then added the 2 sub delays into the Mini-DSP.

I found out two things:

(1) The Denon AVR has a maximum distance of 6m between any two speakers /sub set up! I had just come across this in the AVR as the nearest speaker was shown as 1.0m (behind the MLP), and the sub was shown @ 5.8m (in front of the MLP). So in theory the max distance I could then goto on the sub was 7m (6m plus the 1m closest distance). Dialling in the added distance on the sub setting just bumped up against this limit!



That aside, the sound was brilliant! I thought I may have stumbled on a way to get subs and mains optimised with a little lateral thinking on the mains filters for the MSO calcs!


(2) Although the 'integration' calculations were optimised I found this next problem equally applied to the subs-only configuration! -- the delay on the Sub channel was such that in effect a 'lip sync' type issue occurred on frequencies below the 80Hz crossover! Was watching a film where there was a large impact which rattled into the sub frequencies and just as I can discern a few ms differences between sound and picture for speech and lip sync, the same was true of the 'impact'! The sound was definitely 'too late' for what I saw on the screen! Very disconcerting if the truth be known! So in order to get the 'sub' to be better aligned by not having so much delay in the sub channel, it would mean getting the sub signal to be 'earlier' in terms of the mains speakers. I.e. a negative delay. But that translates to an increase in distance on the sub channel in order in effect to add a net positive delay on all the other channels. But as I was already up at the limit of 6m, I couldn't do this. So in order to get correct timing between sub output and on-screen action, I would have to ignore the delays that the MSO would calculate, even for a sub-only config and optimisation. And that being the case, one may as well not run MSO and Mini-DSP as any manual delays added to the AVR will just throw a spanner in the overall result.

How would this challenge be best overcome to achieve a great response and yet maintain sync between sub and screen action?
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post #1816 of 1830 Old 03-15-2020, 09:23 AM
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Inexperienced question and idea.. Thanks for the reply and have a good day 👍
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post #1817 of 1830 Old 03-16-2020, 06:00 AM
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Originally Posted by Mr_Incredible View Post
In trying to get MSO and the Mini-DSP to work nicely with my AVR with mains integration as well, (i.e. not a sub-only configuration), I set just one filter for the mains at set it at 180Hz and with a minimal boost of 0.1dB and a very narrow range, and did not have a delay block. So when MSO optimised the response across my 3 subs AND the mains, I got a -ve common delay block for all 3 subs, then no delay on one sub and some delays on the other 2. For the -ve common delay block for all 3 subs, I increased the Sub distance in the Amp to correspond to the delay amount, then added the 2 sub delays into the Mini-DSP.

I found out two things:

(1) The Denon AVR has a maximum distance of 6m between any two speakers /sub set up! I had just come across this in the AVR as the nearest speaker was shown as 1.0m (behind the MLP), and the sub was shown @ 5.8m (in front of the MLP). So in theory the max distance I could then goto on the sub was 7m (6m plus the 1m closest distance). Dialling in the added distance on the sub setting just bumped up against this limit!



That aside, the sound was brilliant! I thought I may have stumbled on a way to get subs and mains optimised with a little lateral thinking on the mains filters for the MSO calcs!


(2) Although the 'integration' calculations were optimised I found this next problem equally applied to the subs-only configuration! -- the delay on the Sub channel was such that in effect a 'lip sync' type issue occurred on frequencies below the 80Hz crossover! Was watching a film where there was a large impact which rattled into the sub frequencies and just as I can discern a few ms differences between sound and picture for speech and lip sync, the same was true of the 'impact'! The sound was definitely 'too late' for what I saw on the screen! Very disconcerting if the truth be known! So in order to get the 'sub' to be better aligned by not having so much delay in the sub channel, it would mean getting the sub signal to be 'earlier' in terms of the mains speakers. I.e. a negative delay. But that translates to an increase in distance on the sub channel in order in effect to add a net positive delay on all the other channels. But as I was already up at the limit of 6m, I couldn't do this. So in order to get correct timing between sub output and on-screen action, I would have to ignore the delays that the MSO would calculate, even for a sub-only config and optimisation. And that being the case, one may as well not run MSO and Mini-DSP as any manual delays added to the AVR will just throw a spanner in the overall result.

How would this challenge be best overcome to achieve a great response and yet maintain sync between sub and screen action?
If you "saw" an impact (say from a meteor) from a distance of about a mile, the sound delay would be around 5 seconds. How do you know that the sound engineer wasn't trying to be realistic?

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post #1818 of 1830 Old 03-16-2020, 07:05 AM
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Originally Posted by Mike Wittman View Post
If you "saw" an impact (say from a meteor) from a distance of about a mile, the sound delay would be around 5 seconds. How do you know that the sound engineer wasn't trying to be realistic?

Haha! Very good!
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post #1819 of 1830 Old 03-16-2020, 07:23 AM
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Haha! Very good!
BTW ::

I've been doing what you're attempting for about a year now with great results. Remember though DSP in the signal path introduces delays and this complicates video no doubt.

Originally I did MSO measurements without mains and then later with mains. The best results were MSO with mains, in the sense all MSO results were good but with mains it was superior (I have speakers that can get to 40 Hz easily). Each time I read and reread the MSO UG I learned something new or that I had misinterpreted my original reading.

I did run into your problem with the distance setting on AVR receiver. I solved this by setting AVR distance to actual distance of closest sub, and gain & phase matching to that sub using the subwoofer cabinets. Then I took my measurements & ran MSO.

My best results came from about 3 weeks of 'fiddling' with crossover settings, taking measurements and running MSO. In the end using MSO to "solve" for crossover with mains worked best. You may want to try this.

Good luck my friend .. it's a journey!
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Originally Posted by Mike Wittman View Post
BTW ::

I've been doing what you're attempting for about a year now with great results. Remember though DSP in the signal path introduces delays and this complicates video no doubt.

Originally I did MSO measurements without mains and then later with mains. The best results were MSO with mains, in the sense all MSO results were good but with mains it was superior (I have speakers that can get to 40 Hz easily). Each time I read and reread the MSO UG I learned something new or that I had misinterpreted my original reading.

I did run into your problem with the distance setting on AVR receiver. I solved this by setting AVR distance to actual distance of closest sub, and gain & phase matching to that sub using the subwoofer cabinets. Then I took my measurements & ran MSO.

My best results came from about 3 weeks of 'fiddling' with crossover settings, taking measurements and running MSO. In the end using MSO to "solve" for crossover with mains worked best. You may want to try this.

Good luck my friend .. it's a journey!
Yup, my results (other than the 'sync' issue) were best when running MSO with mains and subs. My speakers easily go down to 30Hz which was a surprise for me. Perhaps my Emotive XPA-DR3 just makes them sing!

I suspect I have a few weeks of similar 'fiddling' ahead me as well. I have 3 subs and an AVR that has 2 sub output. Of course at the moment as per MSO/DSP guidelines, all of them are 'driven' from a single sub output. I may tinker with putting the nearer one on a different output and let XT32 do its job, and then run the other 2 subs via the DSP and an MSO optimisation. Not sure whether that would work or not! Worth a shot I think!
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post #1821 of 1830 Old 03-25-2020, 08:06 PM
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@3ll3d00d , @andyc56 , @sdurani
I wanted to get your opinion on something I have been thinking a lot and can't get my head around. I have 4 subs but treating front two subs as 1 for now so 3 subs. Issue I'm having is what delay/polarity I should be setting but before we go there, what's the basic rule for integrating subs? Generally, in REW thread, the idea is to calculate the distance and delay the closer subs. But why do we do that??? Is that because we want to sound to come from all the subs at the same time at MLP or this generally yields better FR at MLP? What if doing so makes FR bad across seats (even at MLP)? Even then, should the delay be set that way?

I took all subs reading individually with loop back. 2 Subs are at same distance from MLP (back subs ~5.4 feet away) but front subs are way far out ~ 12 feet away. Here is the impulse response of Back subs VS Front. Using REW measurement tool (CTRL+Mouse Click + drag) shows they are all in phase and need to add 1.33ms in back subs to align the phase even though they are very far apart.



based on that, only a very small delay is required to align the impulses. So now is it the delay based on distance or delay that REW is showing using impulse? Or none of these matter and what matters the most is what gives best FR overall?

I'm also attaching REW/MSO files so you guys can see them all. MSO makes it very simple to see the effects of adding delays or Phase Inversion.

REW file: https://www.dropbox.com/s/xikhdt8o6u...ents.mdat?dl=0

MSO File: https://www.dropbox.com/s/tp6j66j5n8...tion.msop?dl=0

Update: As pointed out by Andy, impulse for front subs didn't look right. So I took readings again and they all look fine now. Here is the updated (correct) Rew file
https://www.dropbox.com/s/fziu0laju3...rect.mdat?dl=0
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Last edited by harrisu; 03-25-2020 at 09:54 PM.
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post #1822 of 1830 Old 03-25-2020, 09:04 PM
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The green trace doesn't appear to be that of a sub at all, or at least not of a sub by itself. The giveaway is the fast rise time of the impulse response, which indicates a wide bandwidth. The slow rise time of the blue and purple traces is due to the low-pass filter applied to the subs, and also to the subs' inductance. Did you inadvertently have the mains playing along with the subs for the measurement associated with the green trace?
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post #1823 of 1830 Old 03-25-2020, 09:13 PM
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Originally Posted by andyc56 View Post
The green trace doesn't appear to be that of a sub at all, or at least not of a sub by itself. The giveaway is the fast rise time of the impulse response, which indicates a wide bandwidth. The slow rise time of the blue and purple traces is due to the low-pass filter applied to the subs, and also to the subs' inductance. Did you inadvertently have the mains playing along with the subs for the measurement associated with the green trace?
No just the front subs. No mains in any readings. I have the REW file attached in the post. You can download and see it there as well. FR will clearly show that its a sub response.

Update: I checked again and you are right. For some reason the impulse of front subs looked weird. I took anther reading and now it looks much better and very similar to how back subs impulse looks like. Does that mean that I need to take all the readings again for MSO? Also, regardless of that, the main question was "What's the main factor to use to determine what Delays should be used"? Is it based on the distance b/w subs and MLP or how FR looks over all at MLP or how FR looks over all across seats? Does it really matter if all low frequencies (below 100Hz) arrive at MLP at same time? I mean can we hear that difference. In high frequencies yes we can easily hear if they don't arrive at same time and therefore setting delays properly is very important. Does the same rule apply for Subs or below 100Hz, we can't really tell so what really matters is the best FR over all?

uploaded correct file. Also updated on main post.

Rew File: https://www.dropbox.com/s/fziu0laju3...rect.mdat?dl=0

Last edited by harrisu; 03-25-2020 at 09:52 PM.
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post #1824 of 1830 Old 03-25-2020, 09:59 PM
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...what's the basic rule for integrating subs?
Whatever works in your particular situation. That's why there are valid but varied approaches to multi-sub integration by Geddes, Harman, Lyngdorf, etc.
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Generally, in REW thread, the idea is to calculate the distance and delay the closer subs. But why do we do that??? Is that because we want to sound to come from all the subs at the same time at MLP or this generally yields better FR at MLP? What if doing so makes FR bad across seats (even at MLP)? Even then, should the delay be set that way?
I'm not a proponent of time aligning subs (for reasons discussed in the REW thread), so I can't answer why people do that. 40Hz frequency has a wavelength of almost 30 feet. Our human hearing is not going to notice if the multiple arrival times are off by a little bit for something that large.
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Or none of these matter and what matters the most is what gives best FR overall?
Frequency response is primarily what we humans hear, so that's what matters the most. Get the bass response smooth, and you're ready to work on something else (maybe subwoofer/speaker blending). So while I don't worry much about time alignment (i.e., compensating for distance), I do recommend experimenting with delays (and levels) to see if it smooths out the bass response. Don't be surprised if the delays that work best end up being unrelated to subwoofer distance. Trying various combinations of delays & levels could take years, especially with 3 or 4 subs. Thank goodness Andy for MSO.

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post #1825 of 1830 Old 03-26-2020, 12:59 AM
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Originally Posted by sdurani View Post
Whatever works in your particular situation. That's why there are valid but varied approaches to multi-sub integration by Geddes, Harman, Lyngdorf, etc. I'm not a proponent of time aligning subs (for reasons discussed in the REW thread), so I can't answer why people do that. 40Hz frequency has a wavelength of almost 30 feet. Our human hearing is not going to notice if the multiple arrival times are off by a little bit for something that large. Frequency response is primarily what we humans hear, so that's what matters the most. Get the bass response smooth, and you're ready to work on something else (maybe subwoofer/speaker blending). So while I don't worry much about time alignment (i.e., compensating for distance), I do recommend experimenting with delays (and levels) to see if it smooths out the bass response. Don't be surprised if the delays that work best end up being unrelated to subwoofer distance. Trying various combinations of delays & levels could take years, especially with 3 or 4 subs. Thank goodness Andy for MSO.
Hi Sanjay, hope you are well.

Have you had the opportunity to use or try MSO ?

I suppose the idea would be to mitigate room modes (especially in seating positions) in order to minimise seat to seat variance. I presume that MSO is a useful tool even in dedicated rectangular spaces for the aformentioned goal.

Also, I meant to ask, are you using a MiniDSP 2x4HD ? - I wish it had balanced XLR connectors, I dread ground-loop based interference via RCA.

Last edited by Sam Ash; 03-26-2020 at 01:05 AM.
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post #1826 of 1830 Old 03-26-2020, 02:22 AM
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Does it really matter if all low frequencies (below 100Hz) arrive at MLP at same time?
you hear the combined response at low frequencies so I don't think this Q really makes sense

personally I put some bounds on the range of acceptable sub delays and then align the resulting combined sub with the mains
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post #1827 of 1830 Old 03-26-2020, 08:24 AM
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Have you had the opportunity to use or try MSO ?
Long time ago, to see if it really worked (and it did).
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I meant to ask, are you using a MiniDSP 2x4HD ?
No. I helped a friend add a 2x4 (non-HD) to his system. For my set-up, I used to deploy a Rane RPM-88 combined with a Crown 8150 amp. Then I switched to a Lexicon DD-8+ (same amp as the Crown, but with PEQ built in).

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post #1828 of 1830 Old 03-26-2020, 04:29 PM
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Whatever works in your particular situation. That's why there are valid but varied approaches to multi-sub integration by Geddes, Harman, Lyngdorf, etc. I'm not a proponent of time aligning subs (for reasons discussed in the REW thread), so I can't answer why people do that. 40Hz frequency has a wavelength of almost 30 feet. Our human hearing is not going to notice if the multiple arrival times are off by a little bit for something that large. Frequency response is primarily what we humans hear, so that's what matters the most. Get the bass response smooth, and you're ready to work on something else (maybe subwoofer/speaker blending). So while I don't worry much about time alignment (i.e., compensating for distance), I do recommend experimenting with delays (and levels) to see if it smooths out the bass response. Don't be surprised if the delays that work best end up being unrelated to subwoofer distance. Trying various combinations of delays & levels could take years, especially with 3 or 4 subs. Thank goodness Andy for MSO.
Your reasoning of not bothering much with time alignment makes a lot of sense to me. After taking new readings of my subs, I created MSO project and also added delays to back subs to see what it does. It basically, almost has all the delays to 0. The reason is very obvious. Though having a delay of 6 for back subs does give better response at MLP by giving more low end but then I ask MSO to flatten it out for which it has to get rid of that gain. So It reduces the delay which automatically makes the response more flat.

Here is Before/After (delays have values like of .76 and .69 for back subs)

Befor:


After:

Trace1 = MLP, Trace2 = Right Seat, Trace2 = Left Seat.
I agree that Andy has done an amazing job with MSO. Isn't Dirac 2.0 also coming with something similar?
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Last edited by harrisu; 03-26-2020 at 04:41 PM.
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post #1829 of 1830 Old 03-26-2020, 05:50 PM
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Originally Posted by 3ll3d00d View Post
you hear the combined response at low frequencies so I don't think this Q really makes sense

personally I put some bounds on the range of acceptable sub delays and then align the resulting combined sub with the mains
what's the range of that bound? I put minimum to 0 instead of -20 since we can't enter -ve delays in minidsp HD. Also, as Sunjay mentioned, we can't really hear/detach the delays in low frequencies so why the limit? I guess there is some realistic limits we need to have like up to 10-12ms assuming subs aren't too far away.
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post #1830 of 1830 Old 03-27-2020, 04:39 AM
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Originally Posted by harrisu View Post
what's the range of that bound? I put minimum to 0 instead of -20 since we can't enter -ve delays in minidsp HD. Also, as Sunjay mentioned, we can't really hear/detach the delays in low frequencies so why the limit? I guess there is some realistic limits we need to have like up to 10-12ms assuming subs aren't too far away.
I think I used +/- 5ms, I could say this is half a cycle either way at the top of the pass band but that might be a post facto rationalisation of an arbitrary decision
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