That is hard to accept but, on the other hand, nothing to be ashamed of.
BTW, are there really reviews on this forum? All I see are comments and lively discussion.
To Sub Or Not To Sub, That Is The Question
- Thread starter Mr. Miyagi
- Start date
BTW, are there really reviews on this forum? All I see are comments and lively discussion.
I really hope that you get to understand my cause! There is an objective approach to bass reproduction! First you have to minimize any mechanical resonances in your subwoofer. That is not currently the case and is why this sub no sub forum exists! Subwoofers are resonate devices by design!
https://www.stereotimes.com/post/tbi-magellan-viii-su-subwoofer/
This is a review of our Magellan VII subwoofer in early days. This was the first use of the technology currently used in MS-6P. We have been researching further and have made many additional breakthroughs. In reading this you will see what our continued goals are. I am aiming this information at audiophiles that are obviously not satisfied with adding subs!
I see the graph and it tells me nothing. Our subwoofers create nice sine waves at levels way higher than any 6.5" driver could ever do. And your driver isn't especially light per cm^2 of area, meaning it's not pushing a lot more air per g of driver than a larger one.
We have a dual opposing subwoofer, meaning basically zero vibration and resonance. For fun I created a graph of it in a similar format as yours. Unfortunately this doesn't tell anyone anything.
Yes, bad subwoofers do exist, but competent, musical subwoofers already exist as well. The reason people aren't using them for music isn't because there's a problem with them, it's a combination of various subwoofer myths and the fact that properly integrating subwoofers is difficult.
Our MS-6P is very easy to integrate in any room! It can also achieve output levels greater than 109db in normal size room! Hoffmanns iron law limits what a small subwoofer can output. There is no way that 20Hz can be output from such a small enclosure with 2W input without bypassing the law! That is innovation! Everyone can now have extended bass!
There is no myth as the basic design for current subwoofers is relying on resonance and mass to generate sound! Both are non musical! Frequency response is only part of the story as critical damping is required to complete the utility.
Why are small room acoustics only an issue with low frequencies and subwoofers? We don’t have issues with normal sound sources until the room gets large and we have echos.
Do you have any other real review you can point to that is newer than 20 years old? Also, may I respectfully suggest you don't need to end every sentence you type with "!".
Also, if your technology is that great, you don't need to try and convince people on this forum. Simply send it Stereophile any other established review outlet and I'm sure they'd love to do a review on such a ground-breaking design that will prove everyone here your concept is true.
I am neutral in this fight and don't care one way or the other. I'm making a simple observation, that is all.
Who made you the overlord of WBF?
Respectfully, he hasn't ended every sentence with an exclamation mark as you seem to think. Perhaps be nicer to new members, although that is my simple observation and recommendation.
Thanks for the suggestion. I tend to try to make all of these statements of great importance and overuse the explanation point!
That review, regardless of age, is pointing to the solution for extending the bass to lower frequencies in a small room without acoustic issues. The Magellans had a 15 yr run and there are many other similar reviews for them on the web (Google it). All are six or eight inch drivers with low mass and in small enclosures.
The MS-6P is with new patents and is very new with improvements beyond that of the Magellans. We are using different approaches to reaching unhappy customers. Forums and social media can connect individuals in need with a potential solution. Magazines are typically biased while end customer’s breathe a sigh of relief and spread the word with their own reviews. Innovation is possible in all technologies. There seems to be a general consensus that loudspeaker technology is mired in the 20th century.
Yes, obviously here just to advertise his product with nothing valid to add., just a little blah blah !
He should try Audiogon, they are more gullible over there
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Yes we definitely need a couple of 6,5 inch subs to add the punch !Like several other MBL101 owners here, I feel that the addition of my (2) REL subwoofers has elevated the MBL's to "Mini MBL Extreme" performance!
Well, first of all this isn't correct - small / typical sized rooms have problems in the entire frequency range, and any room would benefit from acoustical treatment / dampening to mitigate this.
Second, we have issues with low frequencies due to the fact that the typical room dimensions are similar to the wavelength (and 1/2 wavelength and 1/4 wavelength) of bass frequencies, creating bass modes or nulls depending on where we are located and where the source (subwoofer) is located. This is just how sound works, regardless of how you design your subwoofer.
Innovation! When you say regardless of how the subwoofer is designed can you be sure? You are saying that room and subwoofer must coexist with these effects. I didn’t say that room modes didn’t exist only that the resonance based subwoofer design is sensitive to the modes and increases/decreases its output when it is exposed to these external pressures. The subwoofer has to be acoustically grounded to avoid the effects. That is our contribution and it works.
There can be other problems with small rooms due to reflections. However, room modes are a function of room dimensions, and other reflective surfaces in the room. For typical rooms the fundamental mode tends to fall into the 50~100+ Hz octave. The wavelengths are long enough to be difficult to manage through treatments. There are many room mode calculators online as well as spreadsheets you can download to assess them for your room. At higher frequencies reflections are more readily absorbed or ignored, depending on their level and time of arrival (a function of room absorption and size respectively). This is pretty basic acoustics, known for many decades. Making a perfect subwoofer will not change fundamental room (or any other) acoustics.
Actually, reflections can be even more distracting in a small untreated room, because they are louder and arrive earlier than in a large room. Flutter/echo cause and effect are well-known, as well as methods to counter them. For planar speakers, comb filter effects from the reverse wave if undamped can also be annoying, requiring sound treatment behind the speaker and/or a large room allowing you to place them further away from the wall behind. Singing in the shower is fun but I wouldn't want my main stereo system in there (even if I could keep it dry).
Edit: @sigbergaudio beat me to the post. As an aside, the argument that subwoofer drivers, or any speaker drivers, are significantly modulated by the room is an extraordinary claim for which I have yet to see any proof. Standing waves exist in the room as determined by its dimensions, and while subwoofer placement can have some impact on their level at the listening position, those modes like other reflections are a function of the room itself. If sound is produced in the room, room acoustics will affect the sound, no matter the driver. Also, while there are things like port resonance, cabinet (box) resonance, resonances among various electromechanical parts of the driver and so forth, a subwoofer (or any speaker) does not operate in resonance except at certain narrow frequencies. Even there (at resonance), the amplifier driving it maintains control unless its output impedance is too high or it is otherwise uncontrolled (e.g. oscillating), so they are not "resonance based" in operation. The best example of a resonance-based circuit is an oscillator, used as a clock source or signal generator, that uses resonance to produce a narrow (ideally single-tone) "pure" output at one frequency.
Active arrays of subs (or other speakers) can be used to control sound waves in a room to reduce the impact of reflections, including room modes, or a single sub could conceivably be controlled to counter modes at the listening position, but that requires simple phase control -- or appropriate sub positioning. The claims seem to focus on reduced subwoofer distortion and greater output power in a smaller size than conventional designs, with the added benefit of somehow eliminating room modes and other reflections. That would be an extraordinary advancement, but I'm from Missouri, I'd have to see proof.
I have no idea exactly what "acoustically grounded" means; presumably, a way to counter and thus null ("ground") voice coil and thus cone movement at certain frequencies (the amplifier does that automatically in normal operation), or drive the cone out of phase to cancel ("ground") the sound impinging on the sub.
I'd still like to read the patents. A quick search didn't help but patent searches are not something I do daily. I get either far too many to wade through, or none with the company name -- probably assigned to the inventors by name?
This will clearly go no further without a third party review and measurements of the sub in a room to demonstrate its claims.
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Interesting subject here. I have found (finally) that I like the lack of room interaction (or reduced interaction) I am getting with Open Backed speakers, as opposed to years of traditional cones in cabinet types.
My next question would thus be - how do Open Backed subs sound? There are some around, mainly as kits. I would really like to know. I note OCD Mikey uses OB subs, and it is these I am wondering about.
Room interaction is more directly behind an open-backed speaker than a conventional speaker, but a large planar speaker will radiate less to the sides and top/bottom than a conventional design, so first reflections are less an issue. One reason I liked my Magnepans, though I usually had a smaller room so damped the back wave as the comb filtering drove me nuts (a short drive).
I have tried open-baffle subs a few times but have not liked them so am not your best resource, sorry. They are usually less sensitive so need more power, the drivers are usually custom or specific to open-baffle systems since there is no box to help control excursion, they tend to not be as clean dynamically (tend to "ring" more and muddy the bass), and the reverse wave creates comb filter effects at the listening position like any panel speaker. I have not played with any in years, but know people who have gone that way and love them, so it is a preference as well as performance thing.
I first tried one decades ago as it seemed the perfect match to my Maggies. I did not like it at all; it was actually worse than the cheap sub I had at the time. Lots of bass, but boomy and mucked up the upper bass/lower midrange due to comb filter effects. I ultimately designed a servo-controlled ported sub with a couple of other tricks that was much cleaner (much lower distortion) and had much better transient response (attack/decay) that integrated well with my Maggies. That was the first of several forays into open-baffle subs but I just never heard one I liked. They are another thing that sounded impressive to me at first listen, but over time their drawbacks outweighed their benefits, at least for me.
FWIWFM - Don
The patent number is available on the site! You really can’t see the improvement made by subwoofer you must experience it. Damping, really critical damping is not there. When you say that the current subwoofer is not base on resonance well I have to disagree! For a subwoofer driver as presently used is requiring excessive moving mass to have resonance at the desired frequency. This moving mass must move back and forth and the more mass the slower the response! Please tell me that I’m not wrong here! Resonance is also a timed event to develop and decay! It’s the wrong way perhaps the only way known to this point! I’m spreading information.
Regardless of who is right here I see too many failures of desired subwoofer results on this forum! To sub or not to sub shouldn’t even be a question as everyone wants a solution that works. You want to extend your bass in your room while maintaining the integrity of your system. It’s possible now through 21st century innovation. Innovation is so scarce for loudspeakers until our local university “Georgia Tech” has removed it from their curriculum! They used to be the center of loudspeaker research.
