• 12-22-2003, 01:06 PM
    Can someone list some servo subs for me please?
    I am interested in purchasing a servo controlled sub and would like to audition some. The Paradigm servo 15 is awesome but a bit out of my price range at the moment. I was wondering if there are any others (well recognized) besides the Velodyne Digital Drive series? Thanks
  • 12-22-2003, 01:17 PM
    This Guy
    if you don't mind
    building a kit. It goes just as low as the paradigm servo-15, but not as loud. Build a 2-4 cubic foot sealed box and you got one awesome sub.


    I think that's about the cheapest you can get, and then a used paradigm servo 15. Good luck

  • 12-23-2003, 09:23 AM
    IMHO, servo control is a special feature (bordering on gimmick) on very high end subs that is not at all necessary for a subwoofer to sound very very good. Subs from companies like HSU and SVS and Velodyne and Paradigm (their non-servo models) with large enough drivers, enclosures and amplifiers will play loud and clean bass with very little distortion (often under the 1% servo threshold) without any servo control. Servo is most needed in models where the manufacturer is trying to keep size to a minimum and still reach extraordinary SPLs. Often, distortion is a minimal factor in subwoofer output until the sub reaches it's extremes at which case it climbs very very quickly. Tom Nousaine et. al. test/define maximum sub SPL at 10% distortion because beyond that SPL, distortion skyrockets. Keep in mind that many folks actually PREFER the slight distortion from non-servo subs at higher volumes. Also keep in mind that servo control makes a sub much less efficient. If budget is no object, get a digital servo Velodyne or Paradigm or Klipsch sub. If money is part of the equation (and it always is) there are other subs with very near the same level of performance for drastically fewer dead presidents.

    Just my $.02.

  • 12-23-2003, 12:38 PM
    Adam, are there any you can think of (non servo) in the 12 inch range you might recommend? Alot of people have recommended the Infinity Alpha 1200 for a sub under $700. My cousin got the Velo CHT12 and though it's good, it's not as tight and clean as I thought it would be but then again, he paid $450 for it so I am sure price has to do with performance. Thanks for any input.
  • 12-23-2003, 01:16 PM
    Acqui, the main factors one needs to decide in purchasing a subwoofer are: How much do I want to spend? How loud do I want/need my sub to go? How low do I want/need my sub to go? How big a subwoofer am I willing to live with?

    Price range is most important. In the range of the Velodyne and the Infinity you mention, I'd consider the Hsu VTF-2 or VTF-3 or the Hsu 1225, the SVS PB-1 or SVS 25-31pci, the Infinity 1000 or 1200, the Paradigm PW-2200, or the Velodyne CHT-15.


    This list might be the most valuable tool in your arsenal as you look for a sub:

    Tom Nousaine is one of the only guys who has measured multiple subwoofers in the same room and published (in the sensible sound) the results. He is a highly respected subwoofer expert. I think his ratings have value. The subwoofers you would expect to be at the top of the list are there: the big Velodyne and Klipsch and Paradigm models. But notice how well the Infinity and Hsu subs compare. Tom has also reviewed SVS subs in glowing terms; it's unfortunate that these do not appear on this list.

    Don't get too hung up on driver size. 15" drivers are not "slower" than 8" drivers. A 40Hz tone is produced by a cone vibrating back and forth 40 times per second. The more air the cone moves, the louder the tone will be. An 8" driver has to move three times as far to create the same SPL as a 15" driver. More cone motion equals greater distortion in almost every case. If enclosure size is not an issue, the bigger the driver, the better.

    Also, don't get hung up on sealed vs. ported designs. Both can sound excellent. Both can sound awful.

    The most important part of implementing any subwoofer into a stereo system is integrating it with the rest of the system. Your cousin can greatly increase the performance from his Velodyne by following a few simple practices. High passing the mains, placing the sub in a corner, setting the level correctly with an SPL meter and implementing an inexpensive parametric equalizer like the Behringer Feedback Destroyer for $100 will all greatly improve subwoofer performance and integration. Nine times out of ten, the lack of "tight"ness and "clean"ness you heard in your cousin's system has to do with room resonances rather than subwoofer deficiencies. Many of us here can help your cousin to get the most from his sub.

    Happy hunting! Keep us posted. And keep asking questions. :^)

  • 12-23-2003, 06:15 PM
    I reread my post and want to add an addendum. I never finished my thoughts about not getting hung up on driver size. All things being equal, bigger is better, but that's not to say that bigger is better across the board. There are 10" designs that outperform 15" designs. The Hsu VTF-2 can go louder and lower than the Velodyne CHT-15 for example. Which is my whole point. Driver size in and of itself means very little, so it's not worth getting hung up on.

  • 12-24-2003, 11:47 AM
    servo sub
    I would have to agree about servo's.A well built sub around a premium driver and outboard bipolar like an adcom will do fine and should give a HT a rocking.Remember also to find the room modes with a test disc and rat shack meter.Any parameteric will cure the room modes and give you the sound you are looking for.I currently use (2) Adire Tumults in separate 2.5 cu. ft. enclosures with (2) Adcom GFA 555mkII's bridged mono.My parameteric of choice is the Behringer 1124p.I'm working on another pair for the back of the room.Talk about over kill
  • 12-25-2003, 09:45 AM

    Distortion is a MAJOR factor in subs, and all woofers in general. If high fidelity audio is your objective, then the LOWER you can get the distortion the better. The bigger subs from the top manufacturers are all well built, have intrinsically low distortion, sound VERY good, and would most likely match most speakers very well. For HT they are all a good choice.

    Unfortunately (or fortunately) some speakers have very low distortion, and even a small addition of distortion can seem glaring. If you choose the wrong sub for a speaker like this, the sub will just not match, and despite what you do with location you will hear a degradation of fidelity.

    Servo technology is NOT a gimmick. It's a well used tool in audio, and many other systems from aircraft flight controls, to the antilock breaking mechanism in your car. It uses a feedback loop to control a system. By doing so you can more accurately control the output of the system. Servo controls work, and work well for subs. You CAN hear a difference!

    Is it worth the extra cost? That will depend on your speakers, and total system, in addition to what you are buying the sub for. In my opinion if you are buying a sub as part of a HT system you should NOT buy a servo sub, as it would be wasted. On the other hand, if you are looking to extend the range of very good speakers, I would definitely consider a servo controlled sub.