Would like to get a review here with a music system! Our favorite customers are panel owners!
To Sub Or Not To Sub, That Is The Question
- Thread starter Mr. Miyagi
- Start date
This graph is without eq with crossover set at 75Hz -12db slope. There is a small peak at 80Hz that I would temper with DSP. The sub is located at the junction of wall and floor actually under a table. It’s using 8 watts to produce this graph with mic on opposite side of room. The satellites that act as mains are crossed over at 100Hz -6db/Oct slope. We find that a shallow slope starting high sounds best! They are not connected for this graph.
Attachments
There is a language barrier or you do not have the same concepts of (or express the same way) acoustics, electronics, and physics that I learned in graduate school and through my career.
Servo control can be applied to sealed, ported, open-baffle, passive radiator-loaded, or dual-driver (opposed or symmetrically driven) speaker systems. Sound is a pressure wave comprising compression and rarefaction. By your definition the air is always "fighting back" when we listen.
Any speaker having sensitivity of about 90 dB/W/m will produce ~95 dB at a listening position of about 3 meters with 20 W input (independent of frequency, although speaker sensitivities at not usually specified at 30 Hz).
My common sense tells me there is no value to my continued participation. Have a good evening!
Why does the cabinet vibrate if there is not pressure that the drivers diaphragm surely feels! That pressure wants to escape. The diaphragm is the path of least resistance.
I am unable to find it. Can you post a link to the webpage where it is presented?
It could be stretched to work for a high order bandpass.
Which is like a kid on a swing, and takes a lot of pumping to get going.
But yeah, you’re right.
A seal box has no resonance by comparison.
^All correct^… and probably a technical disconnect.
“Speed” is often used as a subjective term for group delay, or transcient response.
More so transcient response…
Well this is even more smoothed, this is 1/3rd octave smoothing. You can not judge whether the response is even with this.
The link shows the same 1/6-octave smoothed graph as before, and the range (+120 dB to -190 dB) and step size (10 dB/division) are too large to do meaningful assessment and comparisons.
The sine wave is pretty meaningless; it is at low power (2 W), does not show the start to demonstrate the claimed "speed", and ~1% distortion is virtually impossible to see looking at a sine wave in isolation (without a reference superimposed).
This is the plot of one of my subwoofers, at 5 dB/division, though only goes to 300 Hz (high enough to be beyond the sub's roll-off). The TBI sub goes higher, though that is not necessarily an advantage for a sub since you would have problems integrating with high crossover and the wider bandwidth means more noise and needs more attention to stability.
The sine wave is pretty meaningless; it is at low power (2 W), does not show the start to demonstrate the claimed "speed", and ~1% distortion is virtually impossible to see looking at a sine wave in isolation (without a reference superimposed).
This is the plot of one of my subwoofers, at 5 dB/division, though only goes to 300 Hz (high enough to be beyond the sub's roll-off). The TBI sub goes higher, though that is not necessarily an advantage for a sub since you would have problems integrating with high crossover and the wider bandwidth means more noise and needs more attention to stability.
I’m not sure of your sub model but I’m sure that you are using a larger driver and enclosure. We have a 6.5” with a mass of 32 grams. The frequency response is similar to ours and probably many others. It’s not frequency response that is the issue! The issue is how the subwoofer sounds in the room and I am seeing most audiophiles here on the forum choosing to not use the subwoofer regardless of brand. TBI has technology that acoustically grounds the driver in operation so it is critically damped and not susceptible to modulation from reflected waves from the room. It is difficult to explain how we do it but we have 3 patents that are involved! The speaker driver needs to be critically damped for all of the motion of its diaphragm. If it does not start and stop precisely it cannot accurately track the incoming signal and is subject to modulation from external sources. This is the subject of our HDSS acoustic technology. When it is critically damped the room reflections are ignored so the driver can track the signal. There are always room modes relative to its dimensions where bass can be stronger or weaker but the driver in our MS-6P does not respond to it.
Currently subwoofer drivers operate in a resonate mode and are sensitive to reflections and room position. These acoustic issues cannot be corrected by DSP!
A servo will reduce any "pushback" or "compression" of the air from the room, but the subwoofer itself cannot counter room modes except through placement. I would be interested in seeing the amount of distortion caused by the room modulating a typical subwoofer (or any speaker) driver, and just how much your technology reduces the distortion from such effects.
The problem for most people is not room reflections modulating the subwoofer's driver and increasing its distortion, but the peaks and valleys (especially nulls) in frequency response due to room modes. A perfect subwoofer, with zero distortion, will not help that unless it and/or the listening position is placed to counter the modes.
Unless you have included some sort of active wave technology similar to what Dirac, Trinnov, and others are doing. Even then sub placement is critical.
Are the patents listed on your website?
The problem for most people is not room reflections modulating the subwoofer's driver and increasing its distortion, but the peaks and valleys (especially nulls) in frequency response due to room modes. A perfect subwoofer, with zero distortion, will not help that unless it and/or the listening position is placed to counter the modes.
Unless you have included some sort of active wave technology similar to what Dirac, Trinnov, and others are doing. Even then sub placement is critical.
Are the patents listed on your website?
THOROUGH BASS
tbisubwoofers.com
This is still 1/6th smoothing, and I don't understand why you are showing 10-20,000hz for a subwoofer. But I'll stop asking questions now. Good luck with your new product!
Would you be like to review the subwoofer! When sound is involved listening is the only way to determine its utility of function!
Maybe @Synaxis would like to review one of your subs. He reviews or rather experiences interesting products on his youtube channel.
We are using 10" drivers and 12" drivers. 32g is not especially light for a 6.5" driver, I'd say it's a pretty normal mass.
Bass drivers do not "respond to" the modes in the room. I am afraid this feels like pseudo science intended to make people believe this is something new and better without any ground in reality. As I am a manufacturer as well, I would like to refrain from talking negatively about the competition. So far all I have done is ask questions, but it seems difficult to get answers. So unless anything even close to either a technical explanation or measurements backing up your claims are presented, I don't see the point in continuing this discussion.
Thanks for thinking of me.
I always try and be mindful of what I do videos on, and it appears this sub uses a 6.5" driver?
To be fair to the sub I have a VERY large room and I wouldn't want to use it in a space it's not intended for.
You see the graph! Let’s try 32 grams in any alignment with a 6.5 inch and have a nice sine wave at any level. You need mass and size for current resonant subwoofers! The subwoofer operating at resonance is sensitive to room modes and enhances them. All speakers act as a microphone and when operating at resonance it is inviting stimulation by external pressures! Most of the participants in this forum are in the sub or not sub! If the current theory was effective everyone would have their bass extended and be happy! That is not what I am reading here! Innovation is necessary to acoustically ground the driver! This reduces vibration and the accumulation of unrelated pressure that modulates the diaphragm! You know the boxy sound everyone complains about! A subwoofer is the pinnacle of this issue!
None of that makes any sense to me from an acoustical, electrical, or electromechanical point of view. Perhaps you have invented the warp drive for subwoofers, that contradicts all the decades of theory, practice, and prior art, but this would best be placed in another thread IMO. So far it is a lot of marketing with no technical details and no real data other than a smoothed frequency response plot covering too wide a range to be meaningful and a plot of a sine wave most any sub (and some full-range speakers) could reproduce. Rather than being buried in this thread, start a new thread, and contribute a banner advertisement to further your cause?
The MS-6P doesn’t want to compete with a resonant system attempting to extend the bass! If we can arrange a review it should be stand mounts that don’t go for the lowest notes or electrostatic or magnetic planars. Our customers with panels and stand mounts are those not attempting to extend the bass with a resonate subwoofer! We do have plans to make larger models with same technology that are non resonate and love the room.
I’m not trying to further my cause! I offered to have this subwoofer reviewed on your forum! I’m trying to help some folks on the forum solve the issues that are not being solved! The remarks that I am making regarding resonance is well established! Most subs reside in home theaters!
