To Sub Or Not To Sub, That Is The Question

I want to be very sure we are capturing your claims correctly. This is the plot for an example room showing the peaks and valleys (nulls) in the response due to room modes at various locations in the room:
View attachment 135096

Your claim is that your subwoofer eliminates these peaks and valleys, not just at the listening position, but everywhere in the room? That should be easy to prove by measuring the frequency response at a few points using a conventional subwoofer and then with your subwoofer in the same place.
If you reduce or eliminate the nulls then you don’t have the peaks just variations in level. It’s the high acoustic impedance associated with resonance that is causing the problems!
 
When I went to school turbulence for acoustic waves was an x,y,z,t thing, not two-dimensional. Turbulence within the enclosure is one of many parameters used as part of any modern speaker (or subwoofer) design.


Measuring the response is another way, and less subject to both listener bias and the limitations (lack of sensitivity) of our hearing at subwoofer frequencies. The question is not really of integration, which is usually determined around the crossover frequency, but the ability to cancel reflections (modes) all around the room over a broad band.

You are asking us to believe your claims without proof, buy your subwoofer, then see if we can hear the difference. Great marketing, especially when perceptual bias is considered, but I was hoping for actual proof of your technical claims. That is also easily done. This is not something for which you need a $30,000+ analyzer system; a $100 microphone and free software (REW) can be used to measure the in-room response. You mentioned previously that you could show graphs at several points in the room; a set of unsmoothed graphs taken at several places in the room, along with the locations and room dimensions defined, and the test system used, would be helpful.

Innovation is great but extraordinary claims should be rigorously proven.
I didn’t ask you to buy anything! This is provable information and most proof for loudspeakers is to hear it especially in your own home! No graph is going to guarantee that you will accept the performance. You just don’t want to be stuck with any product that doesn’t perform to your liking. We state on our site that there is a 30 day return policy as is typical. If you are satisfied with your current setup then all is well. I guarantee that it can be better! We have been in business since 2004 if that is a concern.
 
I didn’t ask you to buy anything! This is provable information and most proof for loudspeakers is to hear it especially in your own home! No graph is going to guarantee that you will accept the performance. You just don’t want to be stuck with any product that doesn’t perform to your liking. We state on our site that there is a 30 day return policy as is typical. If you are satisfied with your current setup then all is well. I guarantee that it can be better! We have been in business since 2004 if that is a concern.
Sure sounds like someone trying to sell something :oops: :rolleyes: Pretty desperately !
 
If you reduce or eliminate the nulls then you don’t have the peaks just variations in level. It’s the high acoustic impedance associated with resonance that is causing the problems!
What are peaks if not variations in level? If you eliminate nulls there are still peaks, though again you claim your subwoofer gets rid of (or significantly reduces) room variations so should deal with those as well. Peaks are easy, nulls are hard.

I didn’t ask you to buy anything! This is provable information and most proof for loudspeakers is to hear it especially in your own home! No graph is going to guarantee that you will accept the performance. You just don’t want to be stuck with any product that doesn’t perform to your liking. We state on our site that there is a 30 day return policy as is typical. If you are satisfied with your current setup then all is well. I guarantee that it can be better! We have been in business since 2004 if that is a concern.
Excellent, prove it. Graphs are fine, preferably of several points across the room, and with the components, speakers, measuring system and test conditions documented as for any experiment. Several folk keep asking for that since our time is valuable and integrating a new sub can be time-consuming, plus we have to pay upfront for the sub(s), but so far we've seen no real proof of your claims. There are many subwoofers with low distortion and high SPL but none AFAIK claim to mitigate room modes with a single sub near the speakers.

A high-output, low-distortion, very efficient, small subwoofer is a worthy thing but I am questioning its ability to mitigate room modes as claimed.
 
Sounds like the desperation is among the members that want to extend their bass and can’t due to the lack of innovation!
"Belief", not "innovation". And many of us have already successfully extended our bass using conventional subwoofers and acoustic principles.

Do you have CEA test results for output? You mentioned the sub has a 100-W amplifier in its active version, and achieves 95 dB SPL with 2 W from the amp (at 1 m anechoic?), but is there data showing output vs. distortion across frequency?
 
So are you saying you have created a cardioid sub? Perhaps our cardioid speakers are of interest to you: https://www.sigbergaudio.no/products/sigberg-audio-manta-1-active-speakers

A cardioid subwoofer can certainly improve the frequency response at the listening position, but it has little to do with the driver being affected by the room modes (my understanding of what you said), and will also not be as effective as you are claiming. Looking at your subwoofer I am also still ..doubtful. That you are claiming that people need to listen to understand and that you will not provide measurements proving the effect makes me even more doubtful.
I provided a close measurement of the subwoofer on the site with no eq! It can’t get much better than that. I also provided a spectrum output on the other side of the room with a 75 Hz crossover. This measurement is also without eq. If you don’t believe what you are seeing it’s really nothing more to do. The design does not stimulate the natural room modes!
 
"Belief", not "innovation". And many of us have already successfully extended our bass using conventional subwoofers and acoustic principles.

Do you have CEA test results for output? You mentioned the sub has a 100-W amplifier in its active version, and achieves 95 dB SPL with 2 W from the amp (at 1 m anechoic?), but is there data showing output vs. distortion across frequency?
But many have not! It sounds like a hit or miss situation otherwise the subject of this forum would not exist! Without reference the ear settles and you have the issue with room modes. TBI subwoofers do not! All of our customers have natural low frequency extension regardless of room!

Read our history with our Magellan reviews! Do you believe documented reviews from audiophile reviewers the new products are better than our Magellans they had a 15 year distribution. We have purpose read it there non resonant low frequency extension.

95db@2w? Please provide your reference. We only showed a 20Hz sine wave with a reference to 2w no reference to level. Now if you are familiar with Hoffmans Iron Law you know that is not possible at any level with the dimensions of the MS-6P subwoofer without serious innovation. The free air resonant frequency of the driver is 40Hz. Do the math with so many experts here.
 
But many have not! It sounds like a hit or miss situation otherwise the subject of this forum would not exist! Without reference the ear settles and you have the issue with room modes. TBI subwoofers do not! All of our customers have natural low frequency extension regardless of room!
That is what we are asking you to prove, or at least confirm, with actual measurements and not listening reviews. LF extension is one thing, but doing it while canceling room modes is incredible, and should be easily proven with some frequency response plots.

Read our history with our Magellan reviews! Do you believe documented reviews from audiophile reviewers the new products are better than our Magellans they had a 15 year distribution. We have purpose read it there non resonant low frequency extension.
No, I want to see a graph. Hearing is fallible, particularly at very low frequencies where we are less sensitive, and reviewers too often hear what they want to hear. It took me a while to figure out just how much perceptual bias colored my opinions of various audio gear over the years.

95db@2w? Please provide your reference. We only showed a 20Hz sine wave with a reference to 2w no reference to level. Now if you are familiar with Hoffmans Iron Law you know that is not possible at any level with the dimensions of the MS-6P subwoofer without serious innovation. The free air resonant frequency of the driver is 40Hz. Do the math with so many experts here.
You are correct, I am sorry about that. I got the 95 dB number from one of your reviews but that did not state it was at 2 W. However, I am still curious as to the output you have measured?
 
That is what we are asking you to prove, or at least confirm, with actual measurements and not listening reviews. LF extension is one thing, but doing it while canceling room modes is incredible, and should be easily proven with some frequency response plots.


No, I want to see a graph. Hearing is fallible, particularly at very low frequencies where we are less sensitive, and reviewers too often hear what they want to hear. It took me a while to figure out just how much perceptual bias colored my opinions of various audio gear over the years.


You are correct, I am sorry about that. I got the 95 dB number from one of your reviews but that did not state it was at 2 W. However, I am still curious as to the output you have measured?
Apprehension on steroids here! The ear is the only instrument that you need to know if it works! No nulls here guys ! We will eventually get some reviews on this product but you have a measurement of the sub! It is beating Hoffmans Iron Law or should I say avoiding that situation of compression! Compromise in the meantime until we get adequate feedback from the public and you become a believer.
 
Apprehension on steroids here! The ear is the only instrument that you need to know if it works! No nulls here guys ! We will eventually get some reviews on this product but you have a measurement of the sub! It is beating Hoffmans Iron Law or should I say avoiding that situation of compression! Compromise in the meantime until we get adequate feedback from the public and you become a believer.
Got it. Smoothed plots such as you have shown all too readily mask nulls caused by room modes, which tend to be very narrow (and deep). My compromise is working well enough that I am not interested in a $2500, 6.5" sub with unstated performance and unproven claims of eliminating room modes (nulls). Good luck in your venture, hopefully when you have some verifiable objective data you will post it here.
 
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I provided a close measurement of the subwoofer on the site with no eq! It can’t get much better than that. I also provided a spectrum output on the other side of the room with a 75 Hz crossover. This measurement is also without eq. If you don’t believe what you are seeing it’s really nothing more to do. The design does not stimulate the natural room modes!

First: I have repeatedly explained that your graphs lack any sort of detail. Please provide the graphs with an x-axis of 20-200hz and y-axis of 45-105dB. To ask us to listen to it as way of proof doesn't make any sense. A measurement shows peaks and nulls way better than ears.

Second: Any sub will show close to native response when measured nearfield, even in a room.
Below is one of our subs, nearfield in a room. No smoothing (all your graphs have been 1/3 or 1/6 octave smoothing). As you can see there's not really any peaks or nulls. The story would not be the same if measured at the listening position. It would not with your sub either.

First in your way of providing graphs (for reference):
1724392273490.png


And here in 20-200hz / 45-105dB:
1724392325762.png
 
In Italy,Audiograffiti,one of the biggest distributor in Italy,is selling a Krell master Reference sub at 10.000 euro.
I think is a good price for a top sub.
I had one 12 years ago and i think is an incredible sub
 
Apprehension on steroids here! The ear is the only instrument that you need to know if it works! No nulls here guys ! We will eventually get some reviews on this product but you have a measurement of the sub! It is beating Hoffmans Iron Law or should I say avoiding that situation of compression! Compromise in the meantime until we get adequate feedback from the public and you become a believer.
The data for the passive sub is not smoothed! You can see that on the upper bass! Hoffmans Iron Law? No more!
First: I have repeatedly explained that your graphs lack any sort of detail. Please provide the graphs with an x-axis of 20-200hz and y-axis of 45-105dB. To ask us to listen to it as way of proof doesn't make any sense. A measurement shows peaks and nulls way better than ears.

Second: Any sub will show close to native response when measured nearfield, even in a room.
Below is one of our subs, nearfield in a room. No smoothing (all your graphs have been 1/3 or 1/6 octave smoothing). As you can see there's not really any peaks or nulls. The story would not be the same if measured at the listening position. It would not with your sub either.

First in your way of providing graphs (for reference):
View attachment 135273


And here in 20-200hz / 45-105dB:
View attachment 135274
I provided a spectral response from the listening position with a 75Hz crossover in place. It is basically flat with no eq! It would measure that way from all room positions with small variations in response no nulls. If you can’t hear the nulls what is their importance. Don’t ignore the facts!
 
The data for the passive sub is not smoothed! You can see that on the upper bass! Hoffmans Iron Law? No more!

I provided a spectral response from the listening position with a 75Hz crossover in place. It is basically flat with no eq! It would measure that way from all room positions with small variations in response no nulls. If you can’t hear the nulls what is their importance. Don’t ignore the facts!
The MS-6P is with a 32g moving mass operating in a small enclosure so nothing like it. I guarantee that your sub is with 100’s of grams of moving mass that is resonating making it slow to respond. Speed of response (tracking the signal) is more important than frequency response. That is one of the main problems with big box subwoofers. Time delay and room issues is the main reason that most audiophiles won’t use the resonant sub box!
 

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