Anybody here using an Avalanche?

Discussion in 'Home Theater Projects' started by Mark--M, Jul 28, 2005.

  1. Mark--M

    Mark--M Stunt Coordinator

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    Just wondering if anybody else here purchased an avalance when they went on sale? Seemed to be alot of intrest when the sale started but not much feedback since.

    So what do you guys think of them? I have a 15 in a 5.5cuft box ported to 19 Hz and the really deep stuff is insane. Way better then I expected in terms of output and the SQ is top notch too. But I have the be honest i'm not that impressed with the "upper" bass. The output is less then I expected and the SQ is nothing to brag about either. I'm sort of thinking that the dumb carbon fiber dustcap (I hate that thing) is making a slight noise where it meets the cone at higher freqencys. Hoping thats what it is anyway. Havent had a chance to try and fix it yet.

    Anyway, just wondering what other peoples impressions are?
     
  2. Bryan Michael

    Bryan Michael Supporting Actor

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    i have 4 18 in a ib and it is awsome.. i went from dual av15 in a 25cf ported box and all i have to say is the avalanch blows the doors off the av15.
     
  3. Ryan Schnacke

    Ryan Schnacke Supporting Actor

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    I've heard several comments, about the Avalanches, similar to yours on the soundillusions forum - lots of low end, but little mid-bass. Then I've also heard from people who say they get plenty of output up to 120Hz or so where the crossover.

    What I have NOT heard is someone who has actually measured a reduction in upper bass. Do you have an SPL meter? It would be interesting to actually see some data to support these comments.

    I've also heard some discussion over there about dustcaps not completely glued and how to go about fixing it. It might be worth reading.
     
  4. Bryan Michael

    Bryan Michael Supporting Actor

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    my sub is realey flat in room responce down to 14hz i have a 1 db peak in the 30-40 hz and 2db null 60-70
     
  5. JimPeitersen

    JimPeitersen Second Unit

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    Mark/Ryan,
    The possible mechanical issues notwithstanding, the comments about the "upper bass" on the new subs with linear motor topologies (XBL2, LMT, etc.) seem common on the forums. I would venture a guess that what you are missing is the higher order harmonic distortions (which the human ear is very sensitive to) that you (and many, many others) have mistaken for "upper bass." The distortion is so low on these new subs that people have to get used to the new "sound", as Dan (Adire), Stephen (TC), John (AE), Chad (AA) and others have hinted at. In home theater this should never be a problem anyway, as the highest you should crossover should be the THX suggested 80 hz. Just my .02
    JP
     
  6. SteveCallas

    SteveCallas Second Unit

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    Agreed, I think most who mention a lack in bass in the 50-100hz range without actual measurements to show are just not used to not having bloated or boosted bass in that range. It's somewhat similar to what happens when I would read a post from someone who likes car audio and then bought an SVS and was underwhelmed.
     
  7. Pete Mazz

    Pete Mazz Supporting Actor

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    Blue line is a nearfield measurement of a 180 liter Avalanche 18.


    [​IMG]

    Pete
     
  8. Ryan Schnacke

    Ryan Schnacke Supporting Actor

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    Thanks for the graph Pete. Any comments on perceived mid/upper bass output? The graph does not seem to indicate the kind of mid-bass dropout I hear others complain about. Peaking at about 60Hz and only about 4-5dB down at 120Hz. Plus the peak could be reduced with a larger enclosure or a touch of EQ.
     
  9. Joe L.

    Joe L. Stunt Coordinator

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    Pete Mazz,

    Thanks for the graph.

    I am also building a project with 2 Avalanche 18's. They will each end up in their own sealed 13 cubic foot cabinets.

    It will be a while before I can do any measurement, so perhaps you could answer a few questions about your measurement of an Avalanche 18...

    Was your 180 liter enclosure sealed? or Ported?

    If ported, what was the enclosure tuning frequency?

    Was the amplifier used when you took the measurement "flat" or did it have a bass-boost built in?

    Does the amplifier have its own low-pass-filter (most plate amps do) and what was it set to... (if set to 80Hz it could be affecting the upper part of that curve)

    In other words, do you think the amplifier might be partially responsible for the response you measured?

    Joe L.
     
  10. ThomasW

    ThomasW Cinematographer

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    JonMarsh and I designed this sub, Pete built 2 of them for a client.
    People with enough intelligence to make a nearfield 100ms gated Blackman-Harris MLS plot, are smart enough not to have EQ in the signal path...[​IMG]
     
  11. Joe L.

    Joe L. Stunt Coordinator

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    ThomasW,



    You are very highly respected on the audio forums... I've read many of your posts and responses and never once did I think to question your intelligence... last thing on my mind as I try to learn from your writings.

    I have but a fraction of your knowledge about loudspeaker design, but my question if the amplifier had any effect on the posted response curve was not entirely out of line. I did notice the smiley... I can guess, at least once in your past experience, the amplifier used for the measurement did have an effect, even if not this time. [​IMG]

    I do appreciate knowing that the amplifier had a flat frequency response, as it makes it much easier to interpret the resulting near-field measurement as largely being affected by the enclosure volume (and, of course, the driver itself)

    My sealed enclosures for that same driver will be closer to 370L, close to twice the internal volume, so I expect less of a peak in the response curve, and less to equalize.

    Joe L.
     
  12. ThomasW

    ThomasW Cinematographer

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    Pete's the one that made the plot, he's pretty smart too [​IMG]

    I helped design these but haven't heard them since they were fabricated at Pete's commercial shop in Pennsylvania, for a customer in New York state.

    Here's a link to the webpage where Pete posted some pics of the construction process http://home.comcast.net/~bcwwkg/Adams%20Avalanche.htm

    BTW, this design weighs a ton, and is small compared to your's. I hope you have access to a forklift given the size of your boxes.
     
  13. SteveCallas

    SteveCallas Second Unit

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    Those are some badass looking subs. Any kind of batting or foam insulation on the inside?
     
  14. ThomasW

    ThomasW Cinematographer

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  15. Pete Mazz

    Pete Mazz Supporting Actor

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    The measurement was taken with only the sub hooked up to a pro amp w/o xover, EQ, or rumble filter involved. My guess on the rising response would be an inductance "hump" similar to the Blueprint drivers. With a typical xover freq it should'nt be a problem.

    Pete
     
  16. Mark--M

    Mark--M Stunt Coordinator

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    Good to see others seem to be happy with them. I'm pretty sure my SQ issues are the dustcap, it clicks faintly when i press on a certain part of the cone. I'll try running a bead of CA glue around it when i get the chance.

    I have a SPL meter on the way now too so I'll soon know if the response is down or not. I'll keep you guys updated.
     
  17. SteveCallas

    SteveCallas Second Unit

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    I remember reading on another board about someone who had a gap in their dustcap. They could fit an index card underneath the cap in about half an inch, and when pushing the driver in by the cone, felt air leaking out. You can glue it yourself, but Chad offered to recone it for anyone that had this problem. I don't know if yours is that extreme.

    I will be interested to see how the FR graph turns out.
     
  18. Mike Keith

    Mike Keith Second Unit

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    My nearfield ETF plots shows good to 125 Hz for my 4 Avalanche 18's, the crossover was set to 200Hz.
     
  19. Mark Seaton

    Mark Seaton Supporting Actor

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    Real Name:
    Mark Seaton


    Pete is correct here. The type and tuning of the box will affect the exact center and Q of the hump. For example, a smaller box will make for a higher peak and thereby relatively more attenuation above 60-70Hz. Note the inductance is variable with frequency (actually position as well). More accurately it is a progressively shorted inductance; thereby explaining why a model of the 1kHz inductance does not represent the response properly. A few measurements and a little tweaking can get a model in LspCAD pretty close for the range of interest.
     
  20. Mark--M

    Mark--M Stunt Coordinator

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    I got my SPL Meter today and did some tests. The results seem to confirm what I was thinking. The output is down a little after 50 Hz. And the avalanche in a sealed box is MUCH closer to ported then software predicts. Chad told me this on the phone once and he was dead on. I guess the software programs really dont mean a whole lot when it comes down to real world performance.

    So what do you guys think? Any comments or suggestions? I'm thinking a smaller sealed box is defenatly a better idea considering the difference in output. The smaller size and increased SQ are defenatly worth it. Would 3 cubes be a good choice?


    [​IMG]
     

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