Please Comment Rythmik Direct Servo T/S

Discussion in 'Archived Threads 2001-2004' started by ross ish, Jan 23, 2003.

  1. ross ish

    ross ish Stunt Coordinator

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    Rythmik T/S
    Fs 26; Qms 7.505; Vas 88.41L; Cms .222mm/N; Mms 169.1 g;
    Rms 3.681kg/s; P-dia 259.8mm; Sd 530 sq cm; Qes .59;
    Re 2.698ohms; z 3.264ohms; BL 11.24Tm; Qts .547; no .1689;
    1w spl 85.04Db; 2.83v 89.3Db; xmax 15mm; Pe 350 w; 1.2inch excursion;
    1.6inch voice coil; 1inch surround; 102oz magnet


    Stryke AV12
    Fs 21; Qms 4.41; Qes .399; Qts .366; Vas 88L; Re 2.97; Z 4;
    BL 15tm; Cms .25mmm; Mms 228g; Pe 500w; 1w 85.5; 2.83 89.5;
    xmax 23mm; Sd 498sq cm

    I was looking using either the Rythmik Direct Servo Driver/Amp combo or the Stryke AV12 in a vented 101.5liter enclosure. I do not know much about the Rythmik driver nor do I know much about the inner workings of T/S relationships.
    The above Rythmik driver is designed specifically for the servo plate amp so I do not know if a direct comparison is possible; but any comments on the Rythmik driver good/bad would be appreciated. The higher F3 is due more to elevated bass than premature low roll off.

    The suggested vented box has these parameters to achieve -3Db 14hz with [email protected]:
    110liter, Fb 20hz, F3 27.24hz, heavy fill, 1 vent round flush Dv 122.2mm, Lv 600mm

    My cabinet will be 100liter vented with a single 4inch port 16 inch in lenghth flared both ends. Again any comments regarding the cabinet would sure help out.

    http://www.rythmikaudio.com http://www.stryke.com
     
  2. ThomasW

    ThomasW Cinematographer

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  3. Andrus_R

    Andrus_R Stunt Coordinator

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    Why don't you try calling him? Last time i bugged the hell out of him like i usually do bitching, whining and moaning and he seemed genuinely interested in my satisfaction with his product. So i bought his plate amp, for $139. It came prestine new in an OEM box with no scratches, no dents also no manual. Still, 350watt plate amp with adjustable rumble filter and boost switch? Count me in.[​IMG]
     
  4. Jeffrey Noel

    Jeffrey Noel Screenwriter

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    Andrus, how'd the amp work out? Weren't you having problems with it at first, maybe with the wires? Could have been someone else too. I forget!
     
  5. Andrus_R

    Andrus_R Stunt Coordinator

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    I never had problems with the amp. You must be mistaking me for someone else. I was the guy with tempest magnet problem few threads below.

    Oh btw, amp's 350 [email protected] perfect for tempest. I can turn the gain to 10 o'clock position and it's already too loud. I can't fault the construction either, i mean at this price point 140 - 200, you are comparing apples to oranges. So i chose one with the most power at the cheapest price. It's a hefty amp. Tempest + Amp alone without box is already 40+ lbs! AHHHHHHH shiat.

    One neat feature besides the 350watt is the adjustable damping and rumble filter via two 3-click switches.

    I like it.[​IMG]
     
  6. ross ish

    ross ish Stunt Coordinator

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    Andrus, glad to hear from someone that has one of Rythmik's plate amp. Understanding that you like it makes it a no brainer for me...I am sold. I also blasted Brian at Rythmik with numerous emails. He graciously answered each one and is helping me figuring out venting my sealed box.

    Thomas, I am a rookie in DYI sub boxes. I am not well versed in T/S parameters yet and do not fully understand the interrelationships between each element. That is why this forum exists; to ask for help. Believe me, I need advise and willing to learn. I do not have deep pockets so I want to avoid making a $350 mistake. All I wanted to know if the Rythmik's parameters look ok. My previous thread merely pointed out the existance of the Direct Servo Kit. After gathering the T/S parameters from Brian at Rythmik, I posted this thread for any comments.
     
  7. Jack Gilvey

    Jack Gilvey Producer

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    The AV-12 seems like a much better driver from the specs.

    That 380w amp for $135 is quite a deal, though, especially given the flexibility of the eq.
     
  8. Andrus_R

    Andrus_R Stunt Coordinator

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    All i ask from him or any of my vendor's is that they deliver BRAND NEW WORKING UNBLEMISHED PRODUCTS[​IMG] as they promised. Nothing more, nothing less.

    If they are willing to go beyond that, they get good word of mouth advertisinig from me like Rhythmik.[​IMG]
     
  9. Jack Gilvey

    Jack Gilvey Producer

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  10. Paul Stiles

    Paul Stiles Agent

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    An AV-12 or AV15 (or any other subwoofer driver with dual voice coils) can have one of the coils used as a feedback sense coil in a servo feedback loop. Of course, a driver that is designed from the onset with a coil intended for feedback use will have an advantage.

    Transformer coupling between the two voice coils will limit, somewhat, the effectiveness of the feedback.

    The AV-12 driver does, IMHO, have better performance numbers, but the Rythmik driver's specs, while pretty good in themselves, are "improved" by the application of the servo feedback. Of course, there is no free lunch: the Rythmik driver's improvement comes at the expense of added thermal stress on the voice coil system and the requirement of more amplifier power, plus whatever electronics are needed to process the signal from the sense coil.

    With amplifier power as inexpensive as it is nowadays, the relatively affordable servo feedback driver and amplifier system offered by Rythmic seems to me to be an interesting way of achieving very low frequency extension (with hopefully very low distortion for a subwoofer) in a small physical package.

    I would like to see offered a version with a 15" or 18" metal cone woofer servo feedback system with a switching amplifier of several hundred watts power output.



    Paul
     

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