Help me compare these Subs.

Discussion in 'Speakers' started by GaryJ, Apr 6, 2004.

  1. GaryJ

    GaryJ Stunt Coordinator

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    Hi Guys:

    Given the following frequency response data, which would be the better sub and why.

    Here is the sweep data.

    Fq.Sub 1 Sub 2
    15.75 74 64
    16.69 76 70
    17.68 79 78
    18.73 78 80
    19.84 77 79
    21.02 78 80
    22.27 78 79
    23.60 78 79
    25.00 78 79
    26.79 79 80
    28.00 76 78
    29.37 79 82
    31.50 80 84
    33.37 85 89
    35.36 80 84
    37.46 74 74
    39.96 70 70
    42.04 70 70
    44.54 70 70
    47.19 70 70
    50.00 72 78
    52.97 78 72
    56.12 77 74
    59.46 76 78
    63.00 82 84
    66.74 78 78
    70.71 74 82
    74.92 78 74
    79.37 81 81
    84.09 80 80
    89.09 80.5 79
    94.00 81 80
    100.00 80 80

    Thanks,

    Gary
     
  2. Stephen Houdek

    Stephen Houdek Second Unit

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    This could easily be taken as TROLLing, but I'll give you the benefit of the doubt and ask which one sounds better to you? When you know which one sounds better, buy it.

    As far as the frequency sweep goes I don't see a lot of difference, unless most of your listening is done in the 15hz range.

    Without having plotted it out it appears sub 2 is more uniform across the spectrum if you throw out the 15hz number. But without more information its not even possible to say whether or not the 15hz number is even relevant to the sub under test.
     
  3. Terry St

    Terry St Second Unit

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    They look pretty close. The first one looks like it rolls off at a slightly lower frequency than the first and has a smaller range. (70-81 vs. 64-89) In other words, the first one looks like it goes lower and has a flatter response. You might try running sweeps with both pink noise and white noise just to see if you get consistent results. Maybe try swapping the two subs physical locations as well if you haven't been placing them in the same spot for testing. Also, try placing the mic/meter at different spots in the sweetspot.

    That's what you'd do if you're strictly a numbers man anyways. There is a lot more than numbers to audio though. Personally, I'd throw on some Bach organ music and see which I dig more. It helps to turn off/unplug your mains so you can hear just what the sub is doing. Listen to some deep organ music, bass's, etc.. See if, when a bassist plucks a string, both subs sound like a string being plucked or a just a dull thud. (remember, keep your mains off so you can hear just what the sub is responsible for!) For all I know, the sub that produces better numbers might not be as accurate at reproducing sounds. It would also be useful if you had a way to measure SPL's at specific frequencies (e.g. Say you had a meter that could take input from a notch filter and a microphone, or a microphone and the right software on a computer) This would allow you to check for second-order harmonics/distortion, etc.. (Subs of lesser quality may produce unintended higher frequency sounds in addition to lower frequency sounds). Alternatively, put a blindfold on and have someone spin your randomly on a chair and see if you can pinpoint the subs's location when it's playing low frequency stuff. If you can, odds are you have distortion/harmonics. You shouldn't be able to pinpoint what direction the sub is from your listening position. If you can, either you have your crossover set too high or the sub is a POS and needs to be returned.

    Or... You could just pick the one that looks prettier. [​IMG]

    P.S. Just out of curiosity, which two subs are you testing?
     
  4. GaryJ

    GaryJ Stunt Coordinator

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    Thanks for your response guys:

    I am not trolling I am just trying to leave brand names out of the equation. The frist sub is a sub I already have. The second one is a new one I just bought. I set things up with the new sub for about a week or so in my new room and was pretty happy with everything, then I bought my old sub in and bang I heard a big difference. My old sub sounds much cleaner. I get much better bass drum and Tom Tom decay and just generally better articulation. I had never measured the Fq response so I was very surprised that it went so low. The new sub is a pretty highly rated sub and I am just surprised that to my ears and the sound meter it doesn't seem to be really superior. I am testing them in the same location, well side by side. My old sub (sub 1) was a pretty good sub back when I bought it.

    I am really just checking for some fault in my logic or something I am overlooking.

    Thanks again.

    Gary
     
  5. Terry St

    Terry St Second Unit

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    If your instruments, ears, and wallet are all telling you the same thing...

    P.S. I'm still curious about which subs you're testing. You could always PM me and I'll just promise not to tell. I know it doesn't really matter, but I gots ta know! [​IMG]
     
  6. Wayne A. Pflughaupt

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    Since the percussive sound of the initial pluck is above the sub’s range, with just the sub being played the “dull thud” would be more accurate.

    As Terry noted, the response curves are similar, but there is enough variation in them to account for the differences you’re hearing.

    For instance, the 32-36Hz peak is 4dB higher with the second. The 50Hz and 71Hz signals are also substantially higher.

    After you make a decision, Gary, you might want to look into parametric equalizing. If you have enough headroom available, it would make a dramatic improvement.

    Regards,
    Wayne A. Pflughaupt
     
  7. Terry St

    Terry St Second Unit

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    You won't here the attack, true enough, but you will hear some complexity in the sound on a good sub versus a one-note thumpa on a crappy sub. (Think of a teenager's crappy car sub going thumpa thumpa.) Sound below 80 Hz. is not limited to single frequency notes. A sub can hit all the right volumes at the right frequencies while not being able to reproduce complex sounds accurately. Remember, this is done with your mains off and just the sub on, and with the crossover set properly. On a good sub the sound will definately sound more like a plucked string even though you obviously don't hear certain parts of the pluck.

    P.S. Some Cello music, assuming it goes low enough, does dip under 65Hz.. It obviously won't give you a great test, but Cello music often involves sustained notes which can make what I described above very easy to spot. On a good sub you will hear variations in the sound as the bow drags across the strings and on a bad sub you'll just hear a note. Some subs do better at higher frequencies than lower ones though. However, if a sub can't reproduce the low end of a cello properly it's definately not a keeper.
     
  8. GaryJ

    GaryJ Stunt Coordinator

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    Thanks Wayne:

    I was hopping to hear from you. I have an 8024 Ultracurve that I will be implementing but these are the raw numbers. My inclination now is to return the new sub and just keep my old one.

    When I talk about the Bass and Tom Tom drum I am not referring to the attack but the decay of the drum afterwards. The old sub lets me sense it is a drum decay the new sub is much mor subtle. Another example is the THX opening on SW Ep I. On the new sub the base hits are large and impressive but lack detail. On the old I can hear the different tones at the end of the opening on the new one the tones just seem to change in volume but don’t modulate to different frequencies. On this same DVD the ship flyover at the beginning is impressive from an impact point on the on the new sub but on the old one I can hear the different engine tones as the ship fly’s over.

    I am really surprised but at this point it looks like I would need to do a bit of work to get the new sub to sound as good as the old one. Right now the only upside the new sub possesses is headroom.

    I guess what is in conflict is my expectations of a highly rated new sub and the numbers of my RS meter and my ears.

    Any further input is appreciated.

    Gary
     
  9. Rick Cohen

    Rick Cohen Agent

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    It looks like you might get more benefit from EQ on the old sub then spending money on the new one. I plotted the results and there is little difference in the subs. The 40 to 60 range could use a lift unless your crossover is set pretty low to blend with your mains
     
  10. GaryJ

    GaryJ Stunt Coordinator

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    Thanks Rick:

    I definitely seem to have a large dip and peak to deal with but that is true of both subs. I am crossed over at 80. It still looks like right now there is no reason to move to the new subs.
     
  11. Wayne A. Pflughaupt

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    When you start equalizing that could be the make-or-break difference.

    I think the Ultracurve is a two-channel EQ, right? Why don’t you try EQing them both and make a decision then?

    Regards,
    Wayne A. Pflughaupt
     
  12. Richard_M

    Richard_M Second Unit

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    Hey Gary...

    Check you PM you have mail...
     
  13. GaryJ

    GaryJ Stunt Coordinator

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    Yes the untracurve is two channel so I will give it a try this weekend. One of the subs if front firing and one is down firing if that could make any difference.

    Very interesting so far, not at all what I had expected. I still have a little time to work with the new sub before I have to make the decision to return it.

    Thanks for the input.
     
  14. Michael__M

    Michael__M Stunt Coordinator

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    From postings on this site I would say that front vs down firing wouldn't make a difference. Now from experience, I recently auditioned a down firing sub and didn't like the way it sounded. When I layed it on it's side it seemed to change the tonal qualities quite a bit. I can't really explain it, but front firing seemed to sound better to me. I can't and won't even try to explain this, I just excepted it and moved on.

    Michael
     
  15. GaryJ

    GaryJ Stunt Coordinator

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    Thanks Michael:

    My old sub is front firing and the new one is down firing. In the past I had similar experiences to you where I found I like the sound of the front firning subs. However it always seemed when I was auditioning that the front firing subs were the more expensive ones so I just put it down to that. Also, like you reading the different forums, it would appear that there shouldn't be any difference. Now with your experience and mine seeming to prefer front firning I will see if I can cange the orientation of the down firning sub and add that to my list of experiments this weekend.

    Thanks,

    Gary
     
  16. GaryJ

    GaryJ Stunt Coordinator

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    HI All:

    I tried changing the down firing to front firing but this didn't really work well. I then Eq'd the two subs. The old subs are just much more articulate in the upper bass area however the new one just has far more power at the low end but definitely lacks detail in the upper end. With both subs Eq'd flat they seem to work much better as a team. The old sub working on the upper bass essentialy turning my sattalites into full range speakers and the new sub doing true sub duties crossed over at 40Hz.

    That is the results of this weekends experiments I will keep tweaking and see where things end up. Looks like another pieces added to the HT and nothing taken away.

    Gary
     
  17. Jesse Sharrow

    Jesse Sharrow Supporting Actor

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    I think I have a good idea what the new sub is.
     
  18. GaryJ

    GaryJ Stunt Coordinator

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    Hi Jesse:

    I am sure you can probably guess but I would prefer that you don't guess in the tread. I want to keep this thread about the performance numbers and what the ears are hearing. I don't really want to start a thread about this brand does this and that brand does that. It has been an interesting journey so far and I am getting closer to what I was looking for.

    Gary
     

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