Ron’s New System

[Holmz]

I know how they work as I had the idea of an active bass trap myself. Using subs to kill standing waves is far more effective nor is doing so woo-woo

I've worked with pro audio gear all my adult life as I've had a studio that long too.

Dr Floyd Toole developed the Distributed Bass Array concept which is what we're talking about to kill standing waves. Standing waves can manifest as a bass null or a bass peak ('room mode' as you put it). A peak is when the standing wave reinforces the existing bass note; a null is when it cancels.

Your speakers have rear-firing information and that information has bass energy which is not in phase with the front output after bouncing off the wall behind the speakers. That makes them less prone to standing wave problems (which occur in any room with regular dimensions and even some that don't) but does not eliminate the problem. It does make it a bit easier to deal with.

I’m not sure that that is 100% Ralph.

Ideally one kills waves passively, and then tries to kill what is remaining actively.
(which may be more “at the same time” than a sequential set of steps.)

Just adding more subs may fill in nulls, but of one wants transient response, then they want to remove energy from the room and not add it.
But the only way to decrease the decay time, is to remove the energy.

 

[Atmasphere]

I’m not sure that that is 100% Ralph.

Ideally one kills waves passively, and then tries to kill what is remaining actively.
(which may be more “at the same time” than a sequential set of steps.)

Just adding more subs may fill in nulls, but of one wants transient response, then they want to remove energy from the room and not add it.
But the only way to decrease the decay time, is to remove the energy.

Actually its the other way 'round when it comes to bass. Subs will do about 95% of what needs to be done; traps and DSP can do the remaining 5%. This is because if there is a cancellation (null), no amount of amplifier power can overcome the bass null it since its being cancelled.

The problem usually isn't a bass boom (easy if it is) but a bass cancellation. For traps to really deal with that they must move about the room as the wavelength of the bass note changes; obviously impractical.

By adding subs the goal is not more bass. Its to break up standing waves and that does not take a lot of energy. Standing waves can be (as in Ron's earlier case) responsible for quite a lot of energy in the room; by using subs to break up the standing wave that bass energy peak is vastly reduced or gone entirely.

One other thing that makes this possible: at 80Hz the wavelength is 14 feet. The ear needs the entire waveform to pass by it to detect that a note is there and a few more to winnow out what note it actually is. By that time (in all but the largest rooms) the bass note has bounced all over the room a few times; its 100% reverberant. That means that decay time and time alignment are not important for this to work and a mono bass signal can be used (the main speakers will reproduce harmonics, allowing the listener to locate the bass instrument in the sound stage), so long as the subs are not allowed to go too high. In most rooms, practically speaking, this is about 80Hz. Most of the standing wave problems occur at a lower frequency so this is usually no worries.

 

[MPW]

This is my first post on WBF after being an observer for many years. I briefly met Ron at the Oakland area audio show in 2024 and he encouraged me to participate. So, here it goes.

My primary area of interest in this hobby is room acoustics. Listening seat position, speaker position, subwoofer use, room treatment. There has been discussion in this thread about one of the many uses of subwoofers, to break up standing waves. I just read that Gary Leeds will be demoing just that using VSA subs with Ron’s Clarysis speakers at T.H.E. Show later this week in Costa Mesa. I will be at the show and am particularly interested in this demonstration.

I wanted to share some REW graphs from my personal system to show the power of using subs to break up standing waves. What you are seeing is the before and after frequency response and waterfall graphs. The system uses Fyne F1-12 speakers and two Speaker Hardware sub kits that I built myself powered by a Dayton SA1000 subwoofer amplifier (I will share more about my system in the next couple of weeks and start a dedicated thread). One sub is to the right of the listening position and one is behind and to the left. Notice how flat the frequency response is and how the waterfall graphs do not get out of control after adding in the subs. Bottom line, when done properly this is an “easy” way to dramatically improve sound. I would encourage everyone to check out the demo this week and PM me if you would like any more info. I’m hoping I can help people achieve improved sound through a better understanding of how to use tools like subwoofers and REW.

 

[AudioHR]

This is my first post on WBF after being an observer for many years. I briefly met Ron at the Oakland area audio show in 2024 and he encouraged me to participate. So, here it goes.

My primary area of interest in this hobby is room acoustics. Listening seat position, speaker position, subwoofer use, room treatment. There has been discussion in this thread about one of the many uses of subwoofers, to break up standing waves. I just read that Gary Leeds will be demoing just that using VSA subs with Ron’s Clarysis speakers at T.H.E. Show later this week in Costa Mesa. I will be at the show and am particularly interested in this demonstration.

I wanted to share some REW graphs from my personal system to show the power of using subs to break up standing waves. What you are seeing is the before and after frequency response and waterfall graphs. The system uses Fyne F1-12 speakers and two Speaker Hardware sub kits that I built myself powered by a Dayton SA1000 subwoofer amplifier (I will share more about my system in the next couple of weeks and start a dedicated thread). One sub is to the right of the listening position and one is behind and to the left. Notice how flat the frequency response is and how the waterfall graphs do not get out of control after adding in the subs. Bottom line, when done properly this is an “easy” way to dramatically improve sound. I would encourage everyone to check out the demo this week and PM me if you would like any more info. I’m hoping I can help people achieve improved sound through a better understanding of how to use tools like subwoofers and REW.

Looking forward to your contribution!

 

[The Roominator]

These pics further corroborate the benefit of a Swarm. A flatter and extended frequency response and a reduction in room modes.

 

[Holmz]

These pics further corroborate the benefit of a Swarm. A flatter and extended frequency response and a reduction in room modes.

That seems like a bit of a misleading plot. Why not just plot it from - infinity to infinity to get a straighter line?

The spectrograms do look pretty good though.

 

[The Roominator]

That seems like a bit of a misleading plot. Why not just plot it from - infinity to infinity to get a straighter line?

The spectrograms do look pretty good though.

I'm not sure what you are inferring. Please elaborate.

 

[sbnx]

I'm not sure what you are inferring. Please elaborate.

I think what is being said is that if you zoom out far enough anything looks flat. If you want to look at the frequency response then zoom in. If your average loudness is say 80dB then scaling the Y-axis from 60 to 100 should be good. Also, since you are looking at subwoofers there is no need to plot it out to 20 kHz. from 20 to 200Hz should be fine. See example below which is with a stereo pair of subwoofers crossed over at 30Hz with no DSP. 1/24 Oct smoothing.

 

[The Roominator]

The example was not to show “flat” but rather “flatter” for the subs versus no subs. 1:12 smoothing was used to provide a clearer picture. It is correct that I could have made it flat by extending it to infinity. I also could have done 1:2 smoothing.

The graph to 20kHz was to show overall room response. I guess it was distracting. My bad. Thanks for your comments.

 

[Thundersnow]

The example was not to show “flat” but rather “flatter” for the subs versus no subs. 1:12 smoothing was used to provide a clearer picture. It is correct that I could have made it flat by extending it to infinity. I also could have done 1:2 smoothing.

The graph to 20kHz was to show overall room response. I guess it was distracting. My bad. Thanks for your comments.

Your graph resolution is waaaaaay off. Use 45-105db for the resolution so that we can see a meaningful graph.

 

[Holmz]

I'm not sure what you are inferring. Please elaborate.

Like has been said.
If the room is say 30 dB, and the poeple on the tarmac with the jet engines are 120dB, then that sort of defines a min/max range.

That said, the spectrograms are very good though, and showing it over the whole band is good (IMO).

 

[Ron Resnick]

One small addition: the custom size Acoustic Sciences Corp. Matrix Panel is now installed behind the listening chair.

 

[Johan K]

One small addition: the custom size Acoustic Sciences Corp. Matrix Panel is now installed behind the listening chair.

View attachment 153406


View attachment 153407

It looks neat and tidy, Ron. Good job!
What frequencies do the matrix panel take care of, and what is the biggest difference you hear so far with the panel installed compared to not installed?

/ Jk

 

[Ron Resnick]

For the last several months I've had the Matrix Panel just leaning up against wall section. I wanted to make sure I like the effect before installing it permanently. I think I hear a touch more open sound.

I used Matrix Panels in my dedicated listening room in my apartment in Manhattan for many years with Martin-Logan Prodigys. In that 10 foot wide X 16 foot long room the listening chair was only inches from the rear wall. In that situation I heard a significant improvement with the Matrix Panels behind my head versus drywall -- less closed-in sounding.

I don't hear nearly as big a difference now, as the listening chair is four or five feet in front of the rear wall. In general I think diffusion behind the listening position is a good idea.

 

[microstrip]

For the last several months I've had the Matrix Panel just leaning up against wall section. I wanted to make sure I like the effect before installing it permanently. I think I hear a touch more open sound.

I used Matrix Panels in my dedicated listening room in my apartment in Manhattan for many years with Martin-Logan Prodigys. In that 10 foot wide X 16 foot long room the listening chair was only inches from the rear wall. In that situation I heard a significant improvement with the Matrix Panels behind my head versus drywall -- less closed-in sounding.

I don't hear nearly as big a difference now, as the listening chair is four or five feet in front of the rear wall. In general I think diffusion behind the listening position is a good idea.

Just for those who are not familiar with the Acoustic Sciences Corp. Matrix Panel, it is not a diffuser. Unfortunately proper diffusion needs a significant distance between wall and listener - typically 4-5 feet minimum, depending on the target frequencies. I have used RPG diffusers at a 7 feet distance and they were great. Acoustic Sciences Corp. Matrix Panel is a selective mix of absorption and reflection, and can be of help in the described circumstances, where the listener is close to a back wall. See https://www.acousticsciences.com/product/matrixpanel/

 

[Ron Resnick]

Francisco is correct. The Matrix Panel is a combination of diffusive and reflective properties.

 

[Johan K]

For the last several months I've had the Matrix Panel just leaning up against wall section. I wanted to make sure I like the effect before installing it permanently. I think I hear a touch more open sound.

I used Matrix Panels in my dedicated listening room in my apartment in Manhattan for many years with Martin-Logan Prodigys. In that 10 foot wide X 16 foot long room the listening chair was only inches from the rear wall. In that situation I heard a significant improvement with the Matrix Panels behind my head versus drywall -- less closed-in sounding.

I don't hear nearly as big a difference now, as the listening chair is four or five feet in front of the rear wall. In general I think diffusion behind the listening position is a good idea.

Thank you for that in detail information.

 

[Johan K]

Like you Ron, I have a matrix panel (DIY) behind the listening position maybe 2 feet behind, plus I have three different absorbing/diffusing tubetraps at the floor/wall corner behind the listening position as well. The combination is due to A LOT of trial and error, listening for the best possible results. I am very happy how it turned out.

 

[microstrip]

Francisco is correct. The Matrix Panel is a combination of diffusive and reflective properties.

Well, I would not say "diffusive". Diffusion has a proper meaning and IMO we can't consider that something that is not specular reflection or absorption is forcefully diffusion. Unfortunately the concept of diffusion is poorly and abusively used in most marketing materials - it is why we see so many audiophiles denigrating treated rooms, as many of them are poorly treated and sound terrible.

IMO the RPG page is a reliable source on these matters - see https://www.rpgacoustic.com/ and the many exhaustive graphs in their products data sheets. Or read the pages of the F. Toole book on this subject ...

 

[Folsom]

One small addition: the custom size Acoustic Sciences Corp. Matrix Panel is now installed behind the listening chair.

View attachment 153406

One small addition: the custom size Acoustic Sciences Corp. Matrix Panel is now installed behind the listening chair.

View attachment 153406

Wait a second, that isn't a Freedom chair....