Room EQ and subwoofer management hardware: Anti-Mode X2 by DSPEAKER

[Willem]

Based on Amir’s measurements of LS50 Meta, and other people’s measurements of SVS SB-3000, purely from a distortion standpoint (and because I’m already using an Anti-Mode 8033 unit on my sub, so it is MUCH flatter in low frequency room response than my loudspeakers), it seems logically to me that with my current setup, it makes more sense to high-pass filter the mains much higher than 40Hz, like say 80-100Hz, and let the less distorted and much flatter room response subwoofer pick up the bulk of that lower and sub bass.

-Ed

Which is what I did.

 

[sigbergaudio]

The one I posted just above,couple of my posts away,I'll quote it here as well:

I am aware of Thomas Lund's position on this. I was fortunate enough to meet him last year when he visited to listen to our Manta speakers. In that setup we had symmetrically positioned stereo subwoofers, and we discussed this topic. There are a couple of things to unpack here.

First, with regards to the importance of symmetrically placed stereo sources for bass, and if it really helps to improve immmersiveness;
While I respect the position Thomas has on this, I would say this is still up for some debate. At best I think it varies from person to person how sensitive we are to this. Personally I don't hear a ton of difference between symmetrically placed mono subwoofers vs symmetrically placed stereo subwoofers. My personal theory for why this is, is that most sound sources are so wideband that they have content (part of the fundamental or harmonics) in higher frequencies as well. This helps us perceive it as stereo despite the fact that the lowest notes are in mono, since part of the sound is in fact being reproduced in stereo by the speakers.

If you only have one sub, you of course cannot choose between stereo or mono configuration, as you only have one. Should you then cross over low to keep stereo content? I think that is a compromise where there's no universal right or wrong, as you sacrifice other things that will often be more important. I can think of at least two situations where I would certainly cross over high: 1. If you only have EQ abilities on the sub, and have issues at 50-100hz, high passing the speakers may give you an overall better sound because you can even out the bass. 2. If you have limited dynamic range on the speakers, offloading the bass to the subwoofer may dramatically improve this (as we do by design in our systems).

I would suggest that in most cases, the benefits of crossing high outweighs the possible reduction in envelopment caused by lack of stereo bass. But this is a compromise each individual must decide on for themselves of course.

 

[EddNog]

I am aware of Thomas Lund's position on this. I was fortunate enough to meet him last year when he visited to listen to our Manta speakers. In that setup we had symmetrically positioned stereo subwoofers, and we discussed this topic. There are a couple of things to unpack here.

First, with regards to the importance of symmetrically placed stereo sources for bass, and if it really helps to improve immmersiveness;
While I respect the position Thomas has on this, I would say this is still up for some debate. At best I think it varies from person to person how sensitive we are to this. Personally I don't hear a ton of difference between symmetrically placed mono subwoofers vs symmetrically placed stereo subwoofers. My personal theory for why this is, is that most sound sources are so wideband that they have content (part of the fundamental or harmonics) in higher frequencies as well. This helps us perceive it as stereo despite the fact that the lowest notes are in mono, since part of the sound is in fact being reproduced in stereo by the speakers.

If you only have one sub, you of course cannot choose between stereo or mono configuration, as you only have one. Should you then cross over low to keep stereo content? I think that is a compromise where there's no universal right or wrong, as you sacrifice other things that will often be more important. I can think of at least two situations where I would certainly cross over high: 1. If you only have EQ abilities on the sub, and have issues at 50-100hz, high passing the speakers may give you an overall better sound because you can even out the bass. 2. If you have limited dynamic range on the speakers, offloading the bass to the subwoofer may dramatically improve this (as we do by design in our systems).

I would suggest that in most cases, the benefits of crossing high outweighs the possible reduction in envelopment caused by lack of stereo bass. But this is a compromise each individual must decide on for themselves of course.

Placing the subwoofer dead center between the two speakers also helps mitigate some of the issues of a higher crossover frequencies, too. This is how mine is placed.

-Ed

 

[sigbergaudio]

Placing the subwoofer dead center between the two speakers also helps mitigate some of the issues of a higher crossover frequencies, too. This is how mine is placed.

View attachment 419963

-Ed

Well, perhaps. But that's not always practical, and isn't necessarily the best position (in all rooms) for the most even frequency response. But might work in some rooms.

 

[EddNog]

Well, perhaps. But that's not always practical, and isn't necessarily the best position (in all rooms) for the most even frequency response. But might work in some rooms.

It wasn’t nearly as practical until I got the Anti-Mode 8033. That thing makes almost any placement in my room work okay.

-Ed

 

[Willem]

It wasn’t nearly as practical until I got the Anti-Mode 8033. That thing makes almost any placement in my room work okay.

-E

The AM 8033 is a very good solution if all you need is subwoofer equalization. That is what I used it for, and it was great, particularly considering its low price and ease of use. In your case, a second (perhaps smaller, and sealed) subwoofer like the SB1000 classic (you don't need the filters of the more expensive Pro version) will further improve things, and across a wider listening area. See here for an example of the benefits of even a small second subwoofer: https://archimago.blogspot.com/2020/05/musings-measurements-subwoofers-to.html Highpassing the main speakers from 80-100Hz gives you quite a bit more headroom, and is what I would recommend. Of course, the new X2 takes all this to a higher level without the complexity of other systems. However, I would avoid equalizing the main speakers above, say, 300-400 Hz.

 

[Paffi]

At best I think it varies from person to person how sensitive we are to this. Personally I don't hear a ton of difference between symmetrically placed mono subwoofers vs symmetrically placed stereo subwoofers. My personal theory for why this is, is that most sound sources are so wideband that they have content (part of the fundamental or harmonics) in higher frequencies as well. This helps us perceive it as stereo despite the fact that the lowest notes are in mono, since part of the sound is in fact being reproduced in stereo by the speakers.

As my crossover to the subs (I use 4) is very high (140hz) I made listening tests for myself If this would let to some negative effects in stereo imaging. I came to the conclusion, that the stereo effect also works with mono subs - I simply turned of the amplifier driving the speakers and only listened to the subs. As the crossover is high of course some voices are already to hear coming from the subs - sitting between them, like in an ordinary stereo setup - led to a stereo imaging effect, but only with mono signal on subs. Hence I don´t worry anymore about that.

 

[Willem]

As my crossover to the subs (I use 4) is very high (140hz) I made listening tests for myself If this would let to some negative effects in stereo imaging. I came to the conclusion, that the stereo effect also works with mono subs - I simply turned of the amplifier driving the speakers and only listened to the subs. As the crossover is high of course some voices are already to hear coming from the subs - sitting between them, like in an ordinary stereo setup - led to a stereo imaging effect, but only with mono signal on subs. Hence I don´t worry anymore about that.

This, of course, is a bit odd.

 

[Sokel]

As my crossover to the subs (I use 4) is very high (140hz) I made listening tests for myself If this would let to some negative effects in stereo imaging. I came to the conclusion, that the stereo effect also works with mono subs - I simply turned of the amplifier driving the speakers and only listened to the subs. As the crossover is high of course some voices are already to hear coming from the subs - sitting between them, like in an ordinary stereo setup - led to a stereo imaging effect, but only with mono signal on subs. Hence I don´t worry anymore about that.

What you describe is not a stereo effect,is just some short of a phantom image and of course is not stereo.
Find a way to switch from mono subs to stereo in real time and see what happens with stereo bass content (not all works have it,you'll find examples to the thread posted above).

(140Hz???Why?)

Edit: If the placement is front and back it won't work of course and would also be odd to have 140Hz x-over to drivers several meters away.

 

[Paffi]

Stereo effect is for me the phantom image - but yes, lets split hairs, loose in some theoretical discussion. I've made practical experience with my setup, so no need to tell me from your desktop that it's bullshit and doesn't work.

 

[Peas]

Does anybody happen to know the latency of the X2?

My AVR struggles to measure the device and assumes a very unusual speaker distance of 9.00 meters, which is the maximum possible.

By ear, I would say around 4 ms delay as adding 1.2 m to the physical distance of the subwoofers, the bass is the loudest and most accurate.

There's a new firmware fixing the latency to 5.5 ms approx. in the 0.x modes.

(In 2.1, it's still 7 ms approx. varying with individual filtering.)

Will check and report.