Hi there,
I was having a discussion concerning ported design and a guy claims to have designed a sealed 1.5 cu ft box with a single 12" woofer cone (27mm p-p) that can reach down to 12 Hz.
Now I don't think that 27mm is nearly enough to get anywhere close to achieve output at 12 Hz that is perceptible. The design is servo-controlled. Now correct me if I'm wrong here but don't servo's necessarily limit dynamic range as a byproduct of reducing distortion ?
I mean, in a size enclosure that small, I can't even begin to imagine how much EQ will be required.
A guy then chimed in the discussion and posted a graph on WinISD showing the Shiva driver (modified with 27mm x-max) as an argument to show that a 12" cone (with 27mm x-max) is beefy enough to achieve it.
Now I don't know about you about does that graph look correct ? Considering that it doesn't factor in room gain apparently. Tell me what you think.
Regards,
I was having a discussion concerning ported design and a guy claims to have designed a sealed 1.5 cu ft box with a single 12" woofer cone (27mm p-p) that can reach down to 12 Hz.
Now I don't think that 27mm is nearly enough to get anywhere close to achieve output at 12 Hz that is perceptible. The design is servo-controlled. Now correct me if I'm wrong here but don't servo's necessarily limit dynamic range as a byproduct of reducing distortion ?
I mean, in a size enclosure that small, I can't even begin to imagine how much EQ will be required.
A guy then chimed in the discussion and posted a graph on WinISD showing the Shiva driver (modified with 27mm x-max) as an argument to show that a 12" cone (with 27mm x-max) is beefy enough to achieve it.
Now I don't know about you about does that graph look correct ? Considering that it doesn't factor in room gain apparently. Tell me what you think.
Regards,
Attachments
Yes the design uses a servo-mechanism. My question is really two fold; how on earth can a 12" woofer even one with 27mm p-p in a 1.5 cu ft box (servo or no servo) reproduce a 12 Hz note that one can perceive ?
Second is that a member threw a graph in WinISD showing that a cone with 27mm p-p (used the Adire Shiva which is 14 mm but modified the results to reflect 27mm) can indeed reproduce down that low. Now the graph shows the cone pushing down to 10 Hz at 90 dB's and the member claims that this is done without room gain whatsoever.
So I'm really skeptical of the results. I mean, take those values and put them in a room where room gain might add 8-12 dB's to those figures and it really doesn't look right.
If a servo mechanism limits ultimate output in order to maintain exceedingly low distortion and if the box size is that small then surely the driver will need tons of EQ to shape the response down that low ?
Alright, that's 3 questions.
Thanks.
Regards,
Second is that a member threw a graph in WinISD showing that a cone with 27mm p-p (used the Adire Shiva which is 14 mm but modified the results to reflect 27mm) can indeed reproduce down that low. Now the graph shows the cone pushing down to 10 Hz at 90 dB's and the member claims that this is done without room gain whatsoever.
So I'm really skeptical of the results. I mean, take those values and put them in a room where room gain might add 8-12 dB's to those figures and it really doesn't look right.
If a servo mechanism limits ultimate output in order to maintain exceedingly low distortion and if the box size is that small then surely the driver will need tons of EQ to shape the response down that low ?
Alright, that's 3 questions.
Thanks.Regards,
http://www.rythmikaudio.com/technology.html
ask the guys who do it. Although some of the links at the bottom of the page may answer some of your questions...
ask the guys who do it. Although some of the links at the bottom of the page may answer some of your questions...
89 dB's at what distance ? 1m ? 2m ? 1" from the cone ?
An Epik Conquest managed to hit 102 dB's I think at 12 Hz as reviewed by Tom Nousaine in his largish room.
So 89 dB's in a sealed box without room gain ? Add room which is what, like 8-10 dB's ? You are already at almost 100 dB's at 12 Hz.
Regards,
An Epik Conquest managed to hit 102 dB's I think at 12 Hz as reviewed by Tom Nousaine in his largish room.
So 89 dB's in a sealed box without room gain ? Add room which is what, like 8-10 dB's ? You are already at almost 100 dB's at 12 Hz.
Regards,
Something just tells me that this sub is going to struggle enormously to produce any 12 Hz output.
A 12" cone in a tiny sealed box with 500 watts of power that is servo-controlled. The designer is using a 3" voice coil. I don't know, I think first of all the amount of EQ needed to shape the response curve is going to be insane.
If I had to take a guess I would say 80 dB's maximum in a room down to 12 Hz. Keeping in mind that you need what, like closer to 100 dB's for it to be perceived ?
Does anyone know what the Fathom 13 can muster at 12 Hz ? Any measurements down that low ?
Regards,
A 12" cone in a tiny sealed box with 500 watts of power that is servo-controlled. The designer is using a 3" voice coil. I don't know, I think first of all the amount of EQ needed to shape the response curve is going to be insane.
If I had to take a guess I would say 80 dB's maximum in a room down to 12 Hz. Keeping in mind that you need what, like closer to 100 dB's for it to be perceived ?
Does anyone know what the Fathom 13 can muster at 12 Hz ? Any measurements down that low ?
Regards,
Indeed very difficult even with 27mm to go to 12Hz.
http://www.ultimateavmag.com/images/archivesart/604way.waterfalls.jpg
http://images.google.com/imgres?img...rosoft:en-us:IE-SearchBox&rlz=1I7GGLL_en&sa=N
With 4, 12" sub woofers in a big box + 1000watt amp per driver genelec claims +/- 3db from 24Hz to 150...... its quite surprising if not impossible that a 12" er with a 3" Vc could do 12Hz......in a 1.5cuft box..
http://www.ultimateavmag.com/images/archivesart/604way.waterfalls.jpg
http://images.google.com/imgres?img...rosoft:en-us:IE-SearchBox&rlz=1I7GGLL_en&sa=N
With 4, 12" sub woofers in a big box + 1000watt amp per driver genelec claims +/- 3db from 24Hz to 150...... its quite surprising if not impossible that a 12" er with a 3" Vc could do 12Hz......in a 1.5cuft box..
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