Finding Subwoofer

[ttocs]

Ok. Let's talk Center Channel and Subwoofer.

The audio quality improved when I dedicated 3 subwoofers to only provide the .1 LFE track audio. No Bass Management will go to these subwoofers. This change meant that all BM would now be sent to the Front Left/Right Channels which are set as Large in the processor. So all bass for all Small speakers are now going through the Front Left/Right speakers. This was a great improvement in audio quality of the Center Channel mostly, but also for all the other Small speakers.

Then I played with setting the Center Channel as Large and connecting a subwoofer using High Level Inputs on the sub. This resulted in another improvement in Center Channel audio quality. So much so that I really don't want to change it. But I don't see how I can keep this configuration when there's so much low frequency content on the Center Channel in some movies that goes down to 20Hz at high volume. I'm going to finish running some tests, but when watching a movie at the intended volume level, my center speaker would be toast. Martin Logan told me there is no protection from being damaged by high volume low frequency content and that the speaker should either be managed or use an outboard high pass filter.

I really want to at least keep the Center Channel separate from all others and not have be sharing BM resources. I truly believe that the Center speaker sounds better when the bass rolls off naturally instead of being cutoff by a filter. So I'm going to try using an active crossover that I bought a few years ago and have never plugged in. It's overkill, but it's something I have on hand and is easy to try out. It'll be interesting to discover where its crossover setting ends up at vs the crossover on the sub that's currently connected to the center speaker.

If I could find a passive way to limit the bass that the amp sends to the speaker itself vs what the preamp sends to the amp AND still send all that low bass to the subwoofer, that would be the best runner scenario for me.

Someone posted a link today for a full range center speaker. This is what we all need! Further, all the bed channels should be full range!! But then reality sets in.

[ttocs]

This is the flow chart for my previous post about how to keep the Center Channel autonomous and provide it with its own subwoofing (made up a word).

[marcl]

Agreeing with ttocs point above that it's worth having full range with good bass in the center channel. Here's another way to do it, even if you don't have a Magnepan center. This woofer is made with the same technology as the $15,000 20.7, but just a roughly 2x2ft piece for $750. It responds 50-200Hz, and has a high output with crossover at 200Hz. So you can connect your center output to a DWM and then cross up to your center speaker. Then, set center channel to small and cross to subwoofers below 50Hz.

www.magnepan.com/DWM_and_DW_1_Woofers

[ttocs]

Here's a flow diagram with connection types. This is to show the "current" expectation, but as always, is subject to change based on performance and possible limitations.

Testing begins with measurements, but listening is always the final determinator.

Each Front speaker will have 1, 2, or 3 subwoofers specifically to augment low bass. That’s the theory at this moment. Testing will provide a direction on this. Currently I’m starting out with 2 subwoofers as the goal in mind, but am also planning on doing as much testing with different scenarios as I can. But, if after trying some combinations there becomes a pattern showing reasons to discontinue a particular path, then that will help narrow the scope going forward.

This idea of stacked subs augmenting main stereo speakers has intrigued me for several years. In that time I have discovered zero information in how to set this up, and EXACTLY what the benefits might be. That famous manufacturer of subs that professes using the high connection method has never had helpful information about this either. They recommend stacked stereo pairs to be professionally setup. Further, the high level inputs on their subs are potted to inhibit discovery of how the circuit is designed claiming that no other manufacturer has a circuit which does the same as theirs. So here’s a contradictory statement, I’m a true believer in the high level input method, but since they are only making just enough information about setup available - but no more, make me a skeptic. I’m teaching myself the consequences of stacking multiple subwoofers in a location that is possibly less than ideal but must be used because that’s where the left and right stereo speakers must be.

Separating the .1 LFE channel into dedicated subwoofery is a good thing. I’m glad the XMC-2 makes this possible!

If having dedicated subwoofers is good for LFE, why not the Center Channel? I tried it. It’s a good thing also!

So now that just leaves Bass Management. Ok. Dedicated subwoofery for BM as well. Done.

I’ve got 3 identical subwoofers stacked with no space between them except a thin rubber mat. It’s almost as if they are one cabinet. They are the Martin Logan Dynamo 1100X model, which can be used either in a down firing or front firing orientation, I’ve got them front firing so they match the speaker they are attached to which is a Martin Logan 13A. These subs are pretty nifty. An app controls all aspects so I can change every setting on each sub without moving. Between the app and miniDSP all I need is a chair with a fridge and toilet built-in! The subs are within 1” of the 13A, which is an electrostatic hybrid speaker with dual woofers and dual amps, and has controls for mid-bass and bass. The bass can be changed by +-10dB centered at 75Hz, so I’m counting on this control in order to dial-in the subwoofers more easily.

First on the agenda is to tweak the subs to be the best they can be, then integrate the subs with the 13A, which will require a lot more tweaking - I think, not sure.

For the record, I’ve already begun the preliminary stuff, starting with running ARC on each sub. After that was finished I made some measurements of each sub, then a pair, then all three. Messing with some of the settings yielded improvements. It’s when I got Dirac involved that things became more complicated.

After running Dirac, I would measure with REW, then make a tweak on the subs and repeat the process. The painful part is having to power on the amps for Dirac, then turn them off for REW.

This is going to take some time, but for me it’s fun in both discovery and management of the process.

[marcl]

Curtains!   Remember that Curtains constrain the area where Dirac applies filters, and outside the Curtains Dirac does nothing.  Think about that ... since Dirac does nothing outside the Curtains, you might want the Curtains to be WIDER so that YOU control the boundaries of the target area.

For example, I want my subs to roll off below 16Hz because I don't want to send useless subsonic energy to them.  I also don't need the subs reacting to harmonics above the LFE 120Hz limit.  So I set my Curtains wider and add control points to the Target Curve to force a steep rolloff above and below the range of the subs.

Dirac Target Curve and Curtains, and corresponding REW measurement with filters.

[ttocs]

Cool marcl !!  And here's my result after reading your suggestion.

The blue trace is the Front Right speaker connected to 2 subs connected from the speaker posts to the High Level Inputs on the subs. The subwoofer drivers are approximately equal in plane to the speaker's front woofer, and the sub cabinets are less than 1" away from the speaker. Dirac chose the placement of the low curtain, and it caused the bump at 20Hz. The red trace is the pair of subwoofers as measured through the LFE channel in REW, hence the higher frequency rolloff. Those notes are code for me. It wasn't intended for public viewing. No smoothing.


Per marcl's suggestion I moved the low curtain farther left. I had to play with it and measure a couple times to get it right. So after doing this a couple times, it became apparent that Dirac knows what it's doing. By lining up the curtain at the dotted vertical limit line I got this result. This result is very close to what I was hoping for before I started all of this. I'm happy enough to stop here. But my curiosity says add the third subwoofer and see where that leads. Well, since I don't have a fourth matching sub, I might as well, since I can't have a completed Left channel until I get the fourth.


While this exercise is far from over, these results were actually pretty easy to achieve. The Martin Logan subwoofers are controlled via an App and it makes adjustments super easy, never have to get up from the chair. I played with all of the adjustments many, many, many times. So when I said it's easy, I probably mean it's a lot easier than it would've been if I couldn't use this app to control multiple subs.

[ttocs]

Current component wiring diagram. The subwoofer numbering has changed.


Using the CX3400 will allow me to get what I want for the Center speaker, which is to let it naturally rolloff but still limit any bass that could damage the speaker. The Center and Subwoofer will each have independent crossover settings. After playing with the settings, and if the subwoofer can extend high enough, I'll try higher crossover settings, maybe I'll like it? The Center Subwoofer will be located in front under the Center Speaker so frequency settings are not a concern.

[405x5]

60 days running and still “Finding Subwoofer”!?
I do hope this bears fruit for some but WOW.... I found subwoofer integration (and seamless at that) to be possibly the easiest of all of the configuration concerns I dealt with in my setup.
The simple keys were proportional size, power and then placement, coupled with trusting my musician ears...,.after that....piece of cake.

[ttocs]

Nov 25, 2020 16:18:42 GMT -5 405x5 said:

60 days running and still “Finding Subwoofer”!?
I do hope this bears fruit for some but WOW.... I found subwoofer integration (and seamless at that) to be possibly the easiest of all of the configuration concerns I dealt with in my setup.
The simple keys were proportional size, power and then placement, coupled with trusting my musician ears...,.after that....piece of cake.

Trying new things.
Learning new things.
Having fun.
Great results!
Sharing ideas.
mmmmmm, cake. I'll bake a cake today in addition to the bread!
Having fun.

[405x5]

Nov 25, 2020 16:38:12 GMT -5 ttocs said:

Nov 25, 2020 16:18:42 GMT -5 405x5 said:

60 days running and still “Finding Subwoofer”!?
I do hope this bears fruit for some but WOW.... I found subwoofer integration (and seamless at that) to be possibly the easiest of all of the configuration concerns I dealt with in my setup.
The simple keys were proportional size, power and then placement, coupled with trusting my musician ears...,.after that....piece of cake.

Trying new things.
Learning new things.
Having fun.
Great results!
Sharing ideas.
mmmmmm, cake. I'll bake a cake today in addition to the bread!
Having fun.

NOW you’re talking!
I just found a foil pan to throw my stuffing together for manana. Pumpkin breads are made!

[ttocs]

Nov 25, 2020 16:58:41 GMT -5 405x5 said:

Nov 25, 2020 16:38:12 GMT -5 ttocs said:

Trying new things.
Learning new things.
Having fun.
Great results!
Sharing ideas.
mmmmmm, cake. I'll bake a cake today in addition to the bread!
Having fun.

NOW you’re talking!
I just found a foil pan to throw my stuffing together for manana. Pumpkin breads are made!

I'm not a Chef like some in the Lounge, but I do have fun improving my cooking skills!

This is the same Pyrex bowl my mom used since the late 1950's for the same purpose, proofing the dough.


The bread takes precedent, but the chocolate cake will be next!
We all should zoom a cooking show!! Late tonight let's put the turkeys in together!

[405x5]

Nov 25, 2020 17:21:06 GMT -5 ttocs said:

Nov 25, 2020 16:58:41 GMT -5 405x5 said:

NOW you’re talking!
I just found a foil pan to throw my stuffing together for manana. Pumpkin breads are made!

I'm not a Chef like some in the Lounge, but I do have fun improving my cooking skills!

This is the same Pyrex bowl my mom used since the late 1950's for the same purpose, proofing the dough.
View Attachment

The bread takes precedent, but the chocolate cake will be next!
We all should zoom a cooking show!! Late tonight let's put the turkeys in together!

Oh Mann that bowl’s a classic (everybody had one)

[ttocs]

Spent yesterday shortening most of the cabling and making the newly needed cables as per the diagram above. I may shorten the five going to the Krell amp, but I'm kinda tuckered out altering XLR's for the time being. Now I'm re-doing the power cables with the ever continuing hope of a neater installation.

[hsamwel]

Nov 20, 2020 15:44:13 GMT -5 ttocs said:

Ok. Let's talk Center Channel and Subwoofer.

The audio quality improved when I dedicated 3 subwoofers to only provide the .1 LFE track audio. No Bass Management will go to these subwoofers. This change meant that all BM would now be sent to the Front Left/Right Channels which are set as Large in the processor. So all bass for all Small speakers are now going through the Front Left/Right speakers. This was a great improvement in audio quality of the Center Channel mostly, but also for all the other Small speakers.

Then I played with setting the Center Channel as Large and connecting a subwoofer using High Level Inputs on the sub. This resulted in another improvement in Center Channel audio quality. So much so that I really don't want to change it. But I don't see how I can keep this configuration when there's so much low frequency content on the Center Channel in some movies that goes down to 20Hz at high volume. I'm going to finish running some tests, but when watching a movie at the intended volume level, my center speaker would be toast. Martin Logan told me there is no protection from being damaged by high volume low frequency content and that the speaker should either be managed or use an outboard high pass filter.

I really want to at least keep the Center Channel separate from all others and not have be sharing BM resources. I truly believe that the Center speaker sounds better when the bass rolls off naturally instead of being cutoff by a filter. So I'm going to try using an active crossover that I bought a few years ago and have never plugged in. It's overkill, but it's something I have on hand and is easy to try out. It'll be interesting to discover where its crossover setting ends up at vs the crossover on the sub that's currently connected to the center speaker.

If I could find a passive way to limit the bass that the amp sends to the speaker itself vs what the preamp sends to the amp AND still send all that low bass to the subwoofer, that would be the best runner scenario for me.

Someone posted a link today for a full range center speaker. This is what we all need! Further, all the bed channels should be full range!! But then reality sets in.

I’ve always thought it’s better to have a higher crossover for the center to get clearer dialogue.
Bass under 80hz does muddy the sound!
But I guess Dirac does help with this. DLBC will do even more with getting the integration to
its best.

But really, why would you want to play <80hz through a ”large” center?
There’s no case in the world where the sound would improve with letting a speaker that’s
not capable play to its limits.
However having an own sub for the center with a proper crossover and integration certainly
isn’t wrong.

As Marcl has written the impulse response is faster in the smaller woofers of main speakers.
But still, below 80hz I can’t see the need for a center, L/R yes but center no.

You need to have big *ss boxes for LCR to have them play good/clean below 60hz IMO.

[hsamwel]

Nov 22, 2020 15:42:49 GMT -5 marcl said:

Curtains!   Remember that Curtains constrain the area where Dirac applies filters, and outside the Curtains Dirac does nothing.  Think about that ... since Dirac does nothing outside the Curtains, you might want the Curtains to be WIDER so that YOU control the boundaries of the target area.

For example, I want my subs to roll off below 16Hz because I don't want to send useless subsonic energy to them.  I also don't need the subs reacting to harmonics above the LFE 120Hz limit.  So I set my Curtains wider and add control points to the Target Curve to force a steep rolloff above and below the range of the subs.

Dirac Target Curve and Curtains, and corresponding REW measurement with filters.


View AttachmentView Attachment

Why do you extend your sub out of its capabilities? To me it seems 20hz at 0db is were the drop should be.
IMO you don’t need to steer the drop in the low end. Moving the curtain until you
get it to fall naturally with the measured.

Although I agree with the general point of your post. I do this myself for several speakers, among them my
subwoofers.

[ttocs]

Dec 4, 2020 13:53:25 GMT -5 hsamwel said:

Nov 20, 2020 15:44:13 GMT -5 ttocs said:

Ok. Let's talk Center Channel and Subwoofer.

The audio quality improved when I dedicated 3 subwoofers to only provide the .1 LFE track audio. No Bass Management will go to these subwoofers. This change meant that all BM would now be sent to the Front Left/Right Channels which are set as Large in the processor. So all bass for all Small speakers are now going through the Front Left/Right speakers. This was a great improvement in audio quality of the Center Channel mostly, but also for all the other Small speakers.

Then I played with setting the Center Channel as Large and connecting a subwoofer using High Level Inputs on the sub. This resulted in another improvement in Center Channel audio quality. So much so that I really don't want to change it. But I don't see how I can keep this configuration when there's so much low frequency content on the Center Channel in some movies that goes down to 20Hz at high volume. I'm going to finish running some tests, but when watching a movie at the intended volume level, my center speaker would be toast. Martin Logan told me there is no protection from being damaged by high volume low frequency content and that the speaker should either be managed or use an outboard high pass filter.

I really want to at least keep the Center Channel separate from all others and not have be sharing BM resources. I truly believe that the Center speaker sounds better when the bass rolls off naturally instead of being cutoff by a filter. So I'm going to try using an active crossover that I bought a few years ago and have never plugged in. It's overkill, but it's something I have on hand and is easy to try out. It'll be interesting to discover where its crossover setting ends up at vs the crossover on the sub that's currently connected to the center speaker.

If I could find a passive way to limit the bass that the amp sends to the speaker itself vs what the preamp sends to the amp AND still send all that low bass to the subwoofer, that would be the best runner scenario for me.

I’ve always thought it’s better to have a higher crossover for the center to get clearer dialogue.
Bass under 80hz does muddy the sound!
But I guess Dirac does help with this. DLBC will do even more with getting the integration to
its best.

But really, why would you want to play <80hz through a ”large” center?
There’s no case in the world where the sound would improve with letting a speaker that’s
not capable play to its limits.
However having an own sub for the center with a proper crossover and integration certainly
isn’t wrong.

As Marcl has written the impulse response is faster in the smaller woofers of main speakers.
But still, below 80hz I can’t see the need for a center, L/R yes but center no.

You need to have big *ss boxes for LCR to have them play good/clean below 60hz IMO.

When BM was changed to being sent to the Mains set as Large and LFE was sent to dedicated subs, the sound from all the Small speakers improved. LFE is very disruptive to the finer details in the Center and Surrounds.

Then, when I called the Center channel Large and connected a subwoofer via High Level inputs, this again was an improvement, but I suspect for a different reason. Not sure yet what that reason is. Rel recommends not high passing the speaker connected via High Level to the sub because they feel the natural rolloff of the speaker should be part of the equation, and I agree - to a point. My problem with doing this connection type and not cutting off at least some of the lowest frequencies from the Motif is the strong possibility of damage to the small woofers when 22Hz audio is in the center channel mix in a movie like The Dark Knight. That's the lowest frequency I've come across when I was checking some movies, with most of the low audio being at about 30Hz and above in the Center channel.

So, for safety concerns I'm going to start with using an active XO and see how that goes. This way, I still get a dedicated sub for the Center, and can play with XO with live audio. Plus, there's still another way to use the active XO, which is to connect the amp to a different output farther in the XO's chain and be able to play with separate High-Pass and Low-Pass settings, which is closer to the High Level connection method.

As to LCR playing clean below 60Hz, my L&R have never sounded as good using any bass management in the processor. They measure very well without Dirac, which I don't use for two channel music, yet. I keep trying every time I learn something new, like I did a few days ago, so I will try again soon to see if limiting with the curtains will help. But so far, Dirac has not improved my two channel experience, but I do use on every channel for movies.

Tons O Fun!

Attachments:

[marcl]

Dec 4, 2020 14:05:37 GMT -5 hsamwel said:

Nov 22, 2020 15:42:49 GMT -5 marcl said:

Curtains!   Remember that Curtains constrain the area where Dirac applies filters, and outside the Curtains Dirac does nothing.  Think about that ... since Dirac does nothing outside the Curtains, you might want the Curtains to be WIDER so that YOU control the boundaries of the target area.

For example, I want my subs to roll off below 16Hz because I don't want to send useless subsonic energy to them.  I also don't need the subs reacting to harmonics above the LFE 120Hz limit.  So I set my Curtains wider and add control points to the Target Curve to force a steep rolloff above and below the range of the subs.

Dirac Target Curve and Curtains, and corresponding REW measurement with filters.


View AttachmentView Attachment

Why do you extend your sub out of its capabilities? To me it seems 20hz at 0db is were the drop should be.
IMO you don’t need to steer the drop in the low end. Moving the curtain until you
get it to fall naturally with the measured.

Although I agree with the general point of your post. I do this myself for several speakers, among them my
subwoofers.

My sub is spec'ed to 17Hz and it measures that low.  I sure don't listen to pipe organs that often, but I have measured the 16Hz 32' rank in the Saint Saens Organ Symphony.  So just on principle I let Dirac flatten the response down that low. 

My point in widening the curtains is to use Dirac to limit the response of the subs and also the other speakers.  When you pull the curtains in tight, the speakers are left to respond outside that range.  By widening the curtains and tightening the target curves I explicitly limit the response to what the speakers can do without straining their limits.

[ttocs]

Note to self: Buy more speaker cable even though I think I don't need it.

Just ran out of speaker wire with about 4 feet left. Needed more length after deciding to run under the floor. When I ran the ATMOS and Wides and some extra Mains wires I thought there'd be enough for the "whatever might come up" stuff. Well, there was enough, just enough, to not have to splice. But now things are a lot more organizized. (4 syllables? That seems right.)

[marcl]

Dec 4, 2020 20:25:33 GMT -5 ttocs said:

Note to self: Buy more speaker cable even though I think I don't need it.

Just ran out of speaker wire with about 4 feet left. Needed more length after deciding to run under the floor. When I ran the ATMOS and Wides and some extra Mains wires I thought there'd be enough for the "whatever might come up" stuff. Well, there was enough, just enough, to not have to splice. But now things are a lot more organizized. (4 syllables? That seems right.)

Yep ... one too many times I used ocular regression to figure out how much I needed ... then another Amazon truck a couple days later to finish the job.

[hsamwel]

Dec 4, 2020 21:33:52 GMT -5 marcl said:

Dec 4, 2020 20:25:33 GMT -5 ttocs said:

Note to self: Buy more speaker cable even though I think I don't need it.

Just ran out of speaker wire with about 4 feet left. Needed more length after deciding to run under the floor. When I ran the ATMOS and Wides and some extra Mains wires I thought there'd be enough for the "whatever might come up" stuff. Well, there was enough, just enough, to not have to splice. But now things are a lot more organizized. (4 syllables? That seems right.)

Yep ... one too many times I used ocular regression to figure out how much I needed ... then another Amazon truck a couple days later to finish the job.

Been there, done that.. 

That’s why I lately always plan my purchace by measuring and then add 8-10 feet of cable.
The cables I use for everything but LCR is not so expensive that I need to cheap out..