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WOW! Seen the Rocket UFW-12 graph? (1 Viewer)

Chris Quinn

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Edward J M

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I wonder if this was measured near-field indoors, or outside ground plane.

If it was ground plane, that a hella nice looking curve. Also looks like a steep high pass at 20 Hz, as the response falls 36 dB from 20-10 Hz.
 

Mark Seaton

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I would also make a very safe bet that the 112dB output is NOT at 1m outside. My understanding is that this is a single, long throw, 12" woofer in a sealed box. The displayed measurement could certainly have been made in a corner, or in a room measured at very close proximity. The response certainly looks quite good, but remember the conditions of measurement are very important if you want to compare output levels. I'm sure Mark can clarify how the graphs were measured.

Cheers,
 

Mark Seaton

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I wouldn't get all over anyone yet for measurements, the product isn't even available yet, and I didn't read this to be anything overly official. I'm sure someone will do a review, but do consider that 112dB @ 1m @ 20Hz ground plane(outside) from a sealed box would require the equivalent of a pair of 12" drivers, each moving >35mm each way.

Fortunately room boundaries help quite a bit, but you still can't cheat the physics of the situation. Whether the air gets moved directly by the driver, by the air flow through a port, by the movement of a passive radiator, or even through the coupling of a horn or transmission line, it still has to be moved.
 

Chris Quinn

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Here is MLS' note that he posted with the graph.


"With the following caveats...

This is NO WHERE NEAR MAX output...

This is 'without a normal room-gain" which will (generally speaking) help the low end...

This graph also includes some tests of other functions"



Also somewhere in that thread it was said that the magnet for the driver is 30lbs.
 

Brian Bunge

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Chris,

A sealed sub exhibits a 2nd order rolloff, which is 12dB/octave. If you add a 2nd order filter at the point where the rolloff starts then that'll give you a 4th order rolloff, or 24dB/octave. So in this case it looks to be a 4th order filter at 20Hz in order to give you the 36dB/octave rolloff.

Also, a 30 lb. magnet tells me that the driver is probably not very efficient, which is why you'd mate it with somewhere around 1000W. As a comparison, Adire's Sadhara 12" driver weighed around 40 lbs. when I put in on a scale and the Tumult, which is a 15" driver, weighed 65 lbs. Both of these drivers have heavy cones and very strong magnets. Oh, and both have relatively low efficiency.
 

dave alan

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My guess is that these are quasi-anechoic measurements at around 12" to test the response with no LP filter, a 200Hz LP filter and a 30Hz LP filter.

It would then be true that the output is nowhere near it's potential, at that distance.

In any case, it's an impressive curve. Looks to be another winner from MLS. I'm sure it will do everything a 12" sealed sub can possibly do and look good in the process.

Coupled with the R-DES digital PEQ, it'll be one versatile sub.
 

Mark LS

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Greetings from China...

Mark is right...

This is "in-room" (very large room, BTW) closely miked --- but please note... NOT in a corner... Out in the middle of the test area with no "boundary support"...

Mark... if my memory serves me (only a few days ago)... I think we set up at 1/2 meter...

We had more "gas" for sure... but how much more I'm actually not 100% sure of...

This sub will go to Ed M. (for Secrets) once we have production units in house to send him...

After 16 LONG hellish-like months... I'm satisfied.... This is a very nice sealed sub and should offer fine performance in all respects. I wish to point out that the competition is also FABULOUS and we know this... We will not be all things to all people... Just a fine value --- backed with equally fine Customer Service and Support...

Wishing everyone here a wonderful Holiday Season, and I'd like to also add my sincerest thanks to those of you expressing your condolences on the passing of my Mom a few weeks ago... Your messages brought me great strength and support... Many thanks again...

mls
 

NilsIrland

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Good news to hear that Ed is getting one, I've always enjoyed his reviews. MLS, keep us posted on when we are going to see these start shipping, I'm looking forward to getting a pair.

Nils
 

frank manrique

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quote:

I wouldn't get all over anyone yet for measurements, the product isn't even available yet, and I didn't read this to be anything overly official. I'm sure someone will do a review, but do consider that 112dB @ 1m @ 20Hz ground plane(outside) from a sealed box would require the equivalent of a pair of 12" drivers, each moving >35mm each way.

Fortunately room boundaries help quite a bit, but you still can't cheat the physics of the situation. Whether the air gets moved directly by the driver, by the air flow through a port, by the movement of a passive radiator, or even through the coupling of a horn or transmission line, it still has to be moved.
__________________________________________________ ________

Brilliant as always, Mark! :emoji_thumbsup:

Happy holidays. Cheers!... :)

-THTS

"...hi, my name is Frank...and am an SVS bassaholic..."
 

Ned

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Feb 20, 2000
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112db at 20hz, sealed, one 12" driver, something doesn't jive here.

To compare, the SVS Ultra has ports, probably 3-4x the internal volume and it does about 112db@20hz.
 

Edward J M

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Ned:

The SVS CS/PC Ultra can pull about 100 dB @ 20 Hz @ 10% THD @ 2M GP. This is based on the 20-39PC+ I recently measured which pulled 99 dB in the same test.

All we know from Mark Schifter is that the FR graph was measured indoors, away from corners, with the mic placed close to the woof. So you can't really compare output numbers to other products.

I'll get 'er outside at 2 meters GP and run the numbers. FR, THD, dynamic output (short term sweep), and power compression (slow reverse sweep). And possibly some other tests pending discussions with MLS.

Regards,

Ed
 

Mark Seaton

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Ned- Re-read my posts and Mark Schifter's response. Many assumed the conditions of the measurement, a common point of error. For reference my early post mentioned just how far a pair of 12" drivers would have to move to produce that much. A single driver would of course have to move twice as far.

Cheers,
 

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