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Does it really matter? (sound engineering content)

Discussion in 'Amps and Cabs [BG]' started by Visirale, Sep 9, 2008.


  1. Visirale

    Visirale

    Mar 23, 2003
    Orlando
    So before hitting TalkBass, I never had heard of comb filtering or optimal cab volume (size, not sound) for driver sizes.

    Do things like this REALLY have a considerable role in our sound? Major label acts are still touring with 810s (not in a vertical array mind you!) with cabs that most likely aren't big enough for the speakers in them if you follow equations. But they are still the standard.

    Then we have crazy cabs that have different speaker sizes in the same cab... and by the books, that must be asking for trouble, right?

    I'm just curious to see how players (not engineers) have experienced these factors and if they found them significant enough to take into consideration.

    Not trying to flame any of the numerous engineers here either, I'm just curious.
     
  2. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    What happens when drivers are placed horizontally in a bass cab is exactly what happens when PA cabs are placed horizontally, all that differs is the size of the system. Over the last eight years every major pro-touring sound company in the US has switched from horizontally placed cluster arrays to vertically stacked line arrays, at an average cost of $250k per rig. They would not have done so if it didn't make a significant difference. The majority of bassplayers who have gone to vertical driver alignments in their cabs, myself amoing them, would not go back.
    The main obstacle to all cabs going with vertical driver alignments is the unwillingness of manufacturers to take a chance on marketing something that looks different. They build what sells, and what sells is what 'looks right'.
     
  3. stflbn

    stflbn

    May 10, 2007
    Nashville
    4 10's stacked vertically is bliss as far as I'm concerned. (2 2x10's)
     
  4. Visirale

    Visirale

    Mar 23, 2003
    Orlando
    That does make sense. I have noticed the change in PA systems in concerts I've attended through the years... I think at least.

    Is this considered a horizontal or a vertical array? This is most of what I've been seeing lately, just usually with a lot more speakers and a lot larger, from huge festivals to stadium shows:
    [​IMG]
     
  5. Some of the 'best spec on paper' bass cabs sound the worst to me. Remember, a bass cabinet and amplifier is not meant to be a pure, transparent sound source (even the ones that are marketed as transparant and pure are not to my ear), but rather it is meant to reproduce the bass guitar in a way that sounds like what a you hear on a CD post-production.

    As I've posted many times before, in the literally hundreds of bands I've heard through the years with the bass player using classic 410's and 810's, in the vast majority of cases, the sound out in the room is even, punchy and great!

    Listen with your ears, and be careful about putting too much store in speaker spec's coming from non bass players:smug: If you are looking for stereo speakers, that's a different story.

    Regarding the internal volume of a cab versus the driver, this, on the other hand, seems to have a HUGE impact on the tone, but it's still not a better or worse thing. A big driver (or multiple drivers) in a small box with appropriate tuning can sound VERY good if you are looking for a very articulate, mid present tone. A single speaker in a large box tuned quite low can sound awesome at home, and boomy and scooped on the gig.
     
  6. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    Vertical. Within the top cabs drivers are horizontally mounted, but correctly so, with the drivers arranged Woofer-Midrange-Tweeter-Midrange-Woofer. The outer woofers are crossed over to the midrange drivers no higher than their 1 wavelength center to center distance, the mids are crossed over to the tweeter no higher than their 1 wavelength center to center distance. In the stack the woofers, mids and tweeters are on the same vertical plane. This level of engineering is SOP in the high end PA world, AFAIK it does not exist in any commercial electric bass cab.
     
  7. I don't think that would be a vertical array, although it looks like every major front of house system I've seen over the past 10 years or so. All those speakers next to one another on the horizontal plane seem no different than a typical 410 to me. I don't know much about PA technology though.
     

  8. But aren't there multiple woofers next to each other in the same a horizontal plane? I've taken a pretty close look at PA's like that, and each box seems to have identical drivers, mids and horns in them. How would this work since there are three across. I understand you can put the outermost two cabs 'backwards' to separate the woofers as far apart as possible, but what about that center cab of the three vertical columns?
     
  9. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    Only in the subs, which is fine so long as they are within a quarter wavelength of each other. Since a quarter wavelength at 80 Hz is 3.5 feet it's not a problem. The drivers in the top cabs are arranged per my previous post. How that's done can be seen more clearly in this pic of a JBL Vertec.
    [​IMG]
     
  10. I get that about the subs, which is why they all seem to have them stacked right next to one another. That makes sense.

    I still don't quite get the upper array though. In PA's like the picture above that I've gotten close to, it seems that each box (each one of the three across and 6 or 8 down) are identical boxes. Hence, when you have three across, like in the picture, but definition you have multiple 'mid woofers' horizontally configured. However, I may not be understanding what I'm seeing when I've looked through the grills of the lower row of speakers on one of those flying multiple speaker arrays.

    I know they typically sound darn good all over the room, so they obviously have this stuff figured out.

    K
     
  11. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    If they are three separate boxes with identical drivers they are cluster arrays. They are not like the pictured JBL, which is a single cab that measures about 45 inches wide, stacked vertically in single lines.
     

  12. Ah, that's what I must have seen.
     
  13. seamonkey

    seamonkey

    Aug 6, 2004
    This is a great series of articles on Pro Sound Line arrays
    http://www.gtaust.com/filter/06/08.shtml
    It has good descriptions of what it's all about and what went wrong in the 60's/70's and hung on through recently.

    I'm starting to see the "new look" as no backline on stage. Maybe a big screen behind the band, then they could just project any backline people are use to seeing. :bag:
     
  14. jnewmark

    jnewmark Just wanna play the groove. Supporting Member

    Aug 31, 2006
    Stax 1966
    Third St. Cigar Records staff musician.
    Back to bass cabs.... I'm wondering why Schroeder seems to make the smaller bass cabs, like the 1210R in a horizontal array? I know some users disreguard this and stack the cab so it is vertical, but why do it in the first place?
     
  15. Many 210's are also configured this way. I again am one who in many, many, many 'on the gig' A/B's with 210's in horizontal or vertical position notice no difference in off axis response when using the cab with a bass guitar (although small cabs like that seem to sound better in some situations in horizontal position.. coupled to the floor a bit more). I would guess, maybe with program material like CD's, the comb filtering effect might be more apparant.

    The good news is, if you prefer the sound vertically, you can just tip the cab (and 210's) on its side!
     
  16. Gearhead43

    Gearhead43

    Nov 25, 2007
    NorCal
    +++1!!!

    I have noticed a marked improvement in hearing myself and a drastic decrease in "dead spots" at different distances and locations away from my bass cabs when stacking my two 2-10 cabs in a vertical allignment.
     
  17. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    All I can say is the things that Bill suggests are working for me. It's a noticeable difference to my ears. But when I plug into my old straightback 810, all of a sudden I don't care that it's built "wrong." I also think the issue is way less when you are using a bass cab for stage volume only.

    Still, once you hear a rig set up vertically with a single column of matched drivers, it's really tough to go back.
     
  18. zac2944

    zac2944

    Dec 28, 2004
    Rochester, NY
    I'm not expert, but I don't think the Schroeder 1210 or 1212 are good examples of a horizontal array that results in comb filtering.

    I think most of the sound coming from the driver on the slanted baffle is in the 80Hz-200Hz (mid-bass) range. Because that driver is mounted in such an enclosed space, the mids through highs are attenuated. Since the driver on the slanted baffle is only really producing mid bass frequencies, it is never more than a quarter wavelength away from the other driver. Bill mentioned above that this is why the horizontally arrayed subs in the picture don't suffer from comb filtering. Quarter wavelength for 80Hz-200HZ is about 42"-17" respectively. If my understanding of combfiltering is correct you won't see any in this range since the drivers are within 17" of each other. The front facing driver is the only one that really produces the upper mids, so you don't get any comb filtering there either.

    Hopefully someone with more knowledge then me will chime in here if I'm wrong.
     

  19. There have been many posts about the lack of impact of horizontal versus vertical placement of the 1212 or 1210, and also which side of the cab you stand on, so your hypothesis makes sense.
     
  20. zac2944

    zac2944

    Dec 28, 2004
    Rochester, NY
    I've never noticed this comb effect either and I've tried both setups. My guess is that when you are standing close to your amp the effects aren't as noticeable, and when you're out in front of the whole band it is tough to notice because of all the room interaction with your sound. I would also guess that it takes a trained ear to know what to listen for; and I'm not that guy. Like you say, it might be easier with a CD, or maybe even a constant sine wave test tone. I'll have to try an experiment with my SPL meter and see if I can produce this comb filtering phenomena.

    I would bet that some players get a little confused when they try this exercise because when they stack two 210s vertically and it sounds different they think it has to do with comb filtering when it probably has more to do with their ears being closer to and more on axis with the drivers. Of course things will sound clearer up top and it will sound like you're losing some bottom end. But really I don't think you're losing much bottom end, your are just hearing the mids and highs more so it sounds like there is less bottom.

    Just putting in my $0.02. I might be totally wrong.
     

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