Finding Subwoofer

[Deleted]

Aug 22, 2021 17:59:27 GMT -5 leonski said:

I moved a SINGLE 12" sub from the left side of the room, by the LH main speaker. It was nearest a corner. the effect was a huge boomy and NON MUSICAL bass in the
adjacent den. It was like sitting in a 55 gallon drum. Elsewhere in the main listening area the bass was muddy and indistinct.

I moved the sub about 10 to 12 feet to behind the RH speaker and NOW it is musical, extends very low and is completely non-directional.

I cross the mains (hi pass) about 50 to 55hz at 12db / octave The internal sub crossover is at 40 to 45hz @24db / octave.

As the mains increase, the sub drops off....this fills the gap nicely.

Ya, when I stick my head in the toilet in our spare bathroom some 40ft away I too hear boomy bass. So I moved my sub location 40 ft away in the entertainment room. 
Best place my subwoofer sounds is in the middle of the backyard in open air and I have the frequency curve to prove it when measured 1 meter away from the speakers. 
J/king bro. Just poking a little fun. Don't ask me what my head was doing in the toilet - was a long night. 

[marcl]

Aug 23, 2021 16:10:36 GMT -5 @deleted said:

Aug 22, 2021 17:59:27 GMT -5 leonski said:

I moved a SINGLE 12" sub from the left side of the room, by the LH main speaker. It was nearest a corner. the effect was a huge boomy and NON MUSICAL bass in the
adjacent den. It was like sitting in a 55 gallon drum. Elsewhere in the main listening area the bass was muddy and indistinct.

I moved the sub about 10 to 12 feet to behind the RH speaker and NOW it is musical, extends very low and is completely non-directional.

I cross the mains (hi pass) about 50 to 55hz at 12db / octave The internal sub crossover is at 40 to 45hz @24db / octave.

As the mains increase, the sub drops off....this fills the gap nicely.

Ya, when I stick my head in the toilet in our spare bathroom some 40ft away I too hear boomy bass. So I moved my sub location 40 ft away in the entertainment room. 
Best place my subwoofer sounds is in the middle of the backyard in open air and I have the frequency curve to prove it when measured 1 meter away from the speakers. 
J/king bro. Just poking a little fun. Don't ask me what my head was doing in the toilet - was a long night. 

Then by the principle of reciprocity, this should sound great in your listening room.  

[leonski]

Look up HELMHOLTZ and you'll get a better grip On what I heard.

[Deleted]

Aug 23, 2021 16:28:03 GMT -5 marcl said:

Aug 23, 2021 16:10:36 GMT -5 @deleted said:

Ya, when I stick my head in the toilet in our spare bathroom some 40ft away I too hear boomy bass. So I moved my sub location 40 ft away in the entertainment room. 
Best place my subwoofer sounds is in the middle of the backyard in open air and I have the frequency curve to prove it when measured 1 meter away from the speakers. 
J/king bro. Just poking a little fun. Don't ask me what my head was doing in the toilet - was a long night. 

Then by the principle of reciprocity, this should sound great in your listening room.  

View Attachment

I chuckled several times at your response. Thanks for having a sense of humor!

[ttocs]

msimanyi this should clear up some things, hopefully. I'll post my miniDSP settings next week after I re-run the alignment. Since I've added a device (AntiCables ZERO Autoformers) between the main speakers and amps, I will need to change subwoofer settings for the Speaker Level connected subs, and thus change the miniDSP settings to compensate.

Here are ONLY the BM and LFE signal paths. The Front Left and Front Right bottom subs are wired, whereas the signal to the Rear sub is via VSUB wireless.


The signal from the miniDSP1 goes to each sub's LFE input.

[msimanyi]

Perfect!

Thank you ttocs. I'll report back once my MiniDSP shipment arrives and I have a chance to install, connect and configure it.

Mike

[ttocs]

msimanyi this is the signal flow for the Speaker Level connected subs with my miniDSP3 sending the L&R signals to the Rear Sub5 for smoothing duties.

The more important aspect of this arrangement is for when mono bass is being produced by both fronts causing the biggest null, so the rear sub fills that in enough to make a difference. The null doesn't disappear, but it's mostly gone.

[ttocs]

Standing Waves
Not "Moving Waves", which is an album by Focus (not their greatest effort btw).

A simple visual demonstration of standing waves, nodes. Once the demonstration shows the harmonics, it starts being easier to actually see how any single point in a room will be a problem for some frequencies from a single source, and there's no way to avoid it.

He doesn't show this, but if you imagine a second, and even a third string, playing the same frequency - but in a different location, it would become apparent how multiple sources overlapping would fill-in the nodes. This would demonstrate how multiple subwoofers in various locations help each other to fill-in the nodes at a single listening position.
The guy needs someone to give him a pointer so we don't have to watch him crawling around and blocking the camera with his wonderful physique. Other than that, it's a good visual demo.
 

Below is a graphic showing waves of the same frequency from multiple sources but in different locations. Then I moved the waves vertically so they are stacked onto each other to show how they smooth and fill-in the nodes. My version of an over-simplified visual of what can happen with multiple subwoofers.

[p4t]

Just info about my experiment using dedicated 4 subwoofer for LFE and separate 4 subwoofer for BM. Center sub out as LFE and left sub out as mono. After some testing the results is not good. The subs seems like make a bottoming out (but i am pretty sure it is not) testing the center sub as mono and disable left sub out, it sounds good. Also disable center sub and just using left sub as mono, also sound good. Do not know where the problem is.

[marcl]

Jan 3, 2022 8:45:51 GMT -5 p4t said:

Just info about my experiment using dedicated 4 subwoofer for LFE and separate 4 subwoofer for BM. Center sub out as LFE and left sub out as mono. After some testing the results is not good. The subs seems like make a bottoming out (but i am pretty sure it is not) testing the center sub as mono and disable left sub out, it sounds good. Also disable center sub and just using left sub as mono, also sound good. Do not know where the problem is.

This is interesting.  I think ttocs is the only other person who has tried so many subs so he may comment.

• To run 4 from center and 4 from left, are you using two miniDSP's?
• Are all your speakers set to Small?
• What crossovers are the Small speakers set to?
• Where are the subs placed?  Four corners?  Four wall centers?  Are any of them stacked?

How would you describe "bottoming out" ... more quantitatively.  Boomy?  Distortion?  Worse for LFE content vs small speaker bass?

hahaha ttocs types faster than me 

[ttocs]

Jan 3, 2022 8:45:51 GMT -5 p4t said:

Just info about my experiment using dedicated 4 subwoofer for LFE and separate 4 subwoofer for BM. Center sub out as LFE and left sub out as mono. After some testing the results is not good. The subs seems like make a bottoming out (but i am pretty sure it is not) testing the center sub as mono and disable left sub out, it sounds good. Also disable center sub and just using left sub as mono, also sound good. Do not know where the problem is.

Are you using 8 subwoofers?
How are the speaker channels setup, which are Small, and which are Large - if any?
Are each 4-subwoofer group time aligned?
How are each 4-subwoofer group connected?
Which sound mode is being used to find that the subs seem to bottom out?

[p4t]

I am using 8 subwoofer stack in each corner. The bottom subs for LFE and the top one for BM. I am using dayton 4 in and 8 out dsp (similar to regular 2x4 minidsp, not the HD). 4 subs for LFE time align and for 4 subs BM also time align, but when all 8 subs play the same source it will messed up the alignment, but does not matter cause LFE and BM will be different freq. I set all speakers to small with 80Hz crossover, except center channel I set as large cause have dedicated subs for this. Center sub out connected to dayton input one and then connected to output 1-4 to bottom subs. And left sub out connected to input 2 and output 5-8 then to 4 top subs. The sound mode being use is dolby atmos and center sub as lfe and left sub as mono.

[p4t]

Jan 3, 2022 9:04:06 GMT -5 marcl said:

Jan 3, 2022 8:45:51 GMT -5 p4t said:

Just info about my experiment using dedicated 4 subwoofer for LFE and separate 4 subwoofer for BM. Center sub out as LFE and left sub out as mono. After some testing the results is not good. The subs seems like make a bottoming out (but i am pretty sure it is not) testing the center sub as mono and disable left sub out, it sounds good. Also disable center sub and just using left sub as mono, also sound good. Do not know where the problem is.

This is interesting.  I think ttocs is the only other person who has tried so many subs so he may comment.

• To run 4 from center and 4 from left, are you using two miniDSP's?
• Are all your speakers set to Small?
• What crossovers are the Small speakers set to?
• Where are the subs placed?  Four corners?  Four wall centers?  Are any of them stacked?

How would you describe "bottoming out" ... more quantitatively.  Boomy?  Distortion?  Worse for LFE content vs small speaker bass?

hahaha ttocs types faster than me 

1. Kind of. Using dayton dsp, 4 in and 8 out
2. Yes, except center channel set as large
3. All to 80Hz crossover, except center channel of course
4. All 4 corners, stacked, being the bottom sub for LFE and top subs for BM
the bottoming out sound is really like when your subs bottoming out and distorted.

[marcl]

Jan 3, 2022 23:47:45 GMT -5 p4t said:

Jan 3, 2022 9:04:06 GMT -5 marcl said:

This is interesting.  I think ttocs is the only other person who has tried so many subs so he may comment.

• To run 4 from center and 4 from left, are you using two miniDSP's?
• Are all your speakers set to Small?
• What crossovers are the Small speakers set to?
• Where are the subs placed?  Four corners?  Four wall centers?  Are any of them stacked?

How would you describe "bottoming out" ... more quantitatively.  Boomy?  Distortion?  Worse for LFE content vs small speaker bass?

hahaha ttocs types faster than me 

1. Kind of. Using dayton dsp, 4 in and 8 out
2. Yes, except center channel set as large
3. All to 80Hz crossover, except center channel of course
4. All 4 corners, stacked, being the bottom sub for LFE and top subs for BM
the bottoming out sound is really like when your subs bottoming out and distorted.

+ ttocs

Okay so you're using two of the inputs to the Dayton, one from Center Sub LFE and one from Left Sub Mono.  Each is routed to four outputs.

Are you using Dirac or any PEQ?

Can you measure the response in the room... with REW?

[ttocs]

I'm confused about when "but when all 8 subs play the same source it will messed up the alignment". How could all 8 be playing the same source signal? 4 are playing BM, and 4 are only playing LFE. Should be two different signals, so no cancellation or summing should be possible. And if one group is bottoming then there's something else going on here.

Like marcl said, use REW to measure and find out what each channel is doing.
Compare the following three channels in REW:
LFE (should be +10dB above any Large channel and above the Small channels above their crossover settings)
Center (this is for a baseline, this should be flat so should be easy to see that the LFE is +10dB above this)
Any Small channel (to see the elevated BM, and to see the level of this channel above the crossover setting which should be the same as the Center channel)

Also,
Please try this. Should be simple routing change, like what I can do with miniDSP.
In the Dayton, change the routing for LFE so the routing goes to the bottom subs. This way, the 4 subs will be playing BM and LFE, the top subs will be disconnected for this test. This is exactly how my system is setup.

The way I have tested my system, I tried using separate subs for BM and LFE but discovered that I was working against what is best in the room. So now I use the same subwoofer group for both BM and LFE.

[p4t]

Jan 4, 2022 3:21:43 GMT -5 marcl said:

Jan 3, 2022 23:47:45 GMT -5 p4t said:

1. Kind of. Using dayton dsp, 4 in and 8 out
2. Yes, except center channel set as large
3. All to 80Hz crossover, except center channel of course
4. All 4 corners, stacked, being the bottom sub for LFE and top subs for BM
the bottoming out sound is really like when your subs bottoming out and distorted.

+ ttocs

Okay so you're using two of the inputs to the Dayton, one from Center Sub LFE and one from Left Sub Mono.  Each is routed to four outputs.

Are you using Dirac or any PEQ?

Can you measure the response in the room... with REW?

1. Yes.
2. I am using dirac.
3. I have not try to measure it yet using REW.

[p4t]

Jan 4, 2022 8:25:53 GMT -5 ttocs said:

I'm confused about when "but when all 8 subs play the same source it will messed up the alignment". How could all 8 be playing the same source signal? 4 are playing BM, and 4 are only playing LFE. Should be two different signals, so no cancellation or summing should be possible. And if one group is bottoming then there's something else going on here.

Like marcl said, use REW to measure and find out what each channel is doing.
Compare the following three channels in REW:
LFE (should be +10dB above any Large channel and above the Small channels above their crossover settings)
Center (this is for a baseline, this should be flat so should be easy to see that the LFE is +10dB above this)
Any Small channel (to see the elevated BM, and to see the level of this channel above the crossover setting which should be the same as the Center channel)

Also,
Please try this. Should be simple routing change, like what I can do with miniDSP.
In the Dayton, change the routing for LFE so the routing goes to the bottom subs. This way, the 4 subs will be playing BM and LFE, the top subs will be disconnected for this test. This is exactly how my system is setup.

The way I have tested my system, I tried using separate subs for BM and LFE but discovered that I was working against what is best in the room. So now I use the same subwoofer group for both BM and LFE.

I meant, I try if it is possible to also align each group (LFE and BM) together. So I can also try to make center sub as mono and left sub out also as mono. But that just won’t happen. Sadly I haven’t checked the FR using REW.and now one of the Kube 10B sub is already sold.  So I cannot use this setup anymore. Since these experiment I did already around 3 months ago. Next with the subwoofer I have left I will try place 3 of kube 12B as near field subwoofer. I will keep it updated once I have this setup. 

[marcl]

Jan 4, 2022 10:43:39 GMT -5 p4t said:

Jan 4, 2022 3:21:43 GMT -5 marcl said:

+ ttocs

Okay so you're using two of the inputs to the Dayton, one from Center Sub LFE and one from Left Sub Mono.  Each is routed to four outputs.

Are you using Dirac or any PEQ?

Can you measure the response in the room... with REW?

1. Yes.
2. I am using dirac.
3. I have not try to measure it yet using REW.

Okay. so did you do a full Dirac recalibration with all 8 subs?

And, for each sub output - Center 4 subs, and Left 4 subs - how did the Dirac response look?

And I don't recall if you mentioned ... did you gain match and time align each group of subs in the Dayton before running Dirac?

[ttocs]

Jan 4, 2022 10:51:24 GMT -5 p4t said:

Jan 4, 2022 8:25:53 GMT -5 ttocs said:

I'm confused about when "but when all 8 subs play the same source it will messed up the alignment". How could all 8 be playing the same source signal? 4 are playing BM, and 4 are only playing LFE. Should be two different signals, so no cancellation or summing should be possible. And if one group is bottoming then there's something else going on here.

Like marcl said, use REW to measure and find out what each channel is doing.
Compare the following three channels in REW:
LFE (should be +10dB above any Large channel and above the Small channels above their crossover settings)
Center (this is for a baseline, this should be flat so should be easy to see that the LFE is +10dB above this)
Any Small channel (to see the elevated BM, and to see the level of this channel above the crossover setting which should be the same as the Center channel)

Also,
Please try this. Should be simple routing change, like what I can do with miniDSP.
In the Dayton, change the routing for LFE so the routing goes to the bottom subs. This way, the 4 subs will be playing BM and LFE, the top subs will be disconnected for this test. This is exactly how my system is setup.

The way I have tested my system, I tried using separate subs for BM and LFE but discovered that I was working against what is best in the room. So now I use the same subwoofer group for both BM and LFE.

I meant, I try if it is possible to also align each group (LFE and BM) together. So I can also try to make center sub as mono and left sub out also as mono. But that just won’t happen. Sadly I haven’t checked the FR using REW.and now one of the Kube 10B sub is already sold.  So I cannot use this setup anymore. Since these experiment I did already around 3 months ago. Next with the subwoofer I have left I will try place 3 of kube 12B as near field subwoofer. I will keep it updated once I have this setup. 

Ok, now I get it.

It's very difficult to align two groups of subs when one group is stacked on the other. It's much easier to align all of the subs in a methodical manner. Start with one, like the bottom one in one location, then add the one stacked on top, then add another bottom, then the one on top of it, and so on.

Or, align all the bottoms, then add each additional top.

But aligning all bottoms, then aligning all tops, then trying to align the top group with the bottom group is very problematic in my opinion. When I've tried all sorts of ways to align subs in various combinations, it's only been successful to add one sub at a time and build a group this way.

Of course, there's always DLBC which we don't have. Just connect a bunch of subs to a bunch of outputs and let the software do the work.

[405x5]