There's a problem with people saying they've A/B'd various combinations of cab (or anything else) - and it is that no matter how clinically subjective you try to be your sub-conscious prejudices will always affect your judgement. The only true test is a literally blind one - keep your back turned or wear a blindfold while a (trusted) friend pulls the plugs - now you really are relying on your ears and I'll bet you find it's suddenly not so easy. I use two separate heads to drive two separate cabs but only because I like to be loud enough and have plenty of headroom. I agree you should try to build a rig that is as theoretically efficient as you can but there's no need to get tied up in astrophysics - playing bass in a rock band is more about blood and guts than oscilloscopes and graph paper. Two recent gigs - one in a pub's back room measuring about 30'x20' with a low ceiling, a wooden floor (beer cellar below) and a stage that was really just a wooden box about a foot high. This was incredibly bassy - I put my cabs on plastic beer crates to try and de-couple them from the floor but still sounded muddy all night. The other gig was a barbecue party in a cavernous barn at least 100'x40' solid concrete floor, stone walls 2' thick and at least 20' high to a bare slate roof - absolutely zero bass response - I sounded punchy all night but no real bottom end fullness. Okay, extremes I know but my point is that both nights were really good and everyone went home happy. Plenty of other times the sound has been great but the gig less enjoyable - given a choice I definitely know which I'd prefer.
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Mixing Cabinets and Phase Response.
- Thread starter IvanMike
- Start date
The crates do nothing to trap the low end, though if high enough would help somewhat. Next time put one cab up on another, but leave the bottom cab disconnected. Or put a cab up on an empty wooden case. Voila! Instant bass trap.
And be careful where your cabs are in relation to a wall (or walls and corners) as they can exaggerate the low end.
With regards to everyone went home happy...I agree, I'll take a great, enthusiastic crowd with less than stellar acoustics over a boring night with great sound too. But, I'd prefer to have a great crowd and great sound.
And I also agree that rock music ain't about the sound technicians and there is appeal to the rawness of it all. Still, if there were no interest in the science of sound or trying to improve one's sound through proven means, then Talkbass would die a slow death.
My point being that basses do not sound good through perfectly flat speakers or amps. Having used hundreds of mics and dozens of preamps my ear always prefers the less than flat mic. Same for speakers.
To further use the PA analogy phase issues are always bad when combining multiple identical cabinets. You would get severe lobing wherever you had two adjacent cabinets spilling over on each other. Now make that top and bottom as well! Until line arrays existed this was a real problem. Didnt everyone notice when big PAs got 100% better a few years ago? Line arrays! Bass amps arent line arrays.
To further use the PA analogy phase issues are always bad when combining multiple identical cabinets. You would get severe lobing wherever you had two adjacent cabinets spilling over on each other. Now make that top and bottom as well! Until line arrays existed this was a real problem. Didnt everyone notice when big PAs got 100% better a few years ago? Line arrays! Bass amps arent line arrays.
There are only two ways to design bass cabs. They are either designed to be flat, or to exaggerate certain frequencies. There is no voodoo or magic mojo dust sprinkled on some cabs and not others.
If you don't like the way bass cabs sound that are designed to be flat, then you only need to EQ it to your liking...provided the speakers can physically handle the adjustments at a given volume, or you have an EQ capable of doing so.
If you don't like cabs that exaggerate frequencies (at the expense of others) then you may or may not be able to EQ it to your liking because the cab may be designed with certain frequencies so strong or lacking as to not be able to compensate with an EQ (again depending on how exaggerated and if the EQ is capable).
In either case, it's the ability of the EQ (and the user) that will determine whether or not you will like the sound produced from either type of cab. If you are using a bass amp with a limited EQ then you are stuck with finding a cab that is designed to match your amp's ability to produce the sound you like. If you like a more scooped sound, then you have to find a cab designed with scooped mids because you can't EQ it in. Same with any exaggerated frequency...some cabs have more pronounced mids, some lack low end, some are more scooped sounding. It's all in the design. That's why some people like cabs with exaggerated frequencies over cabs that are flat. And why some cabs are liked more than others. Just different designs where those exaggerations are either liked or disliked because of a limited EQ capability and nothing more. A cab designed to be flat does not have to remain so. That's what EQ's are for...boosting or cutting to your desired tonal level.
If you have an amp with an extensive EQ section like parametric and graphic, or you use an outboard EQ, then you increase the chances of finding a sound you like from either type of cab.
Either way, the fault lies mostly with the end user, not the equipment (or lack thereof).
Hey we all have our likes and dislikes with our sound and how we get there is our own personal journey.
Bass cabs aren't line arrays when only one speaker is involved. When you have more than one, then they most certainly are. It just depends on what direction you want that line going that will determine the best sound those speakers will produce. A line array does not have to be vertical...it just happens to work best that way. Take a 410 cab. You actually have four line arrays (two horizontal and two vertical). An 810? Two vertical and four horizontal line arrays. Now, because all of the speakers are in a single cab, the lows and low mids are not as affected (to the point of being unnoticed), but the mids and highs are to the degree of angle you are standing from that cab. That is just how it works. Liking or disliking the sound produced from that is a different matter. I love the tight punchy lo-mids of an Ampeg 810. That is it's design and why many like it, but also why many don't. And if there is any phasing involved from moving around, it may or may not be a big enough issue to want a different cab. It's no big deal if you don't mind that, but the phasing is still there regardless. Personally I don't like frequencies dropping out as I move about, but hey...to each his own.
Regarding phase cancellation in the low end, it can and does happen, though typically not with a single source stage rig. Bass players who put cabs on both sides of the drummer will have phase cancellation in the low end. I most frequently notice low end phase cancellation in PA subs. The degree of it depends on the size of the club. Most bands in clubs put PA subs on both sides of the stage mostly because they just make convenient stands for the PA mains (mids and high) and also because everyone has always done it that way. Next time you listen to a band that does this, walk from one side of the club to the other and see if you don't notice the low end drop out somewhere along your travel. Phase cancellation. With my band, depending on the club, we either use one PA sub or we put both together on one side or the other, or in the middle if the stage is high enough. You'd be surprised how dramatic the effect is. Put your subs together and the low end will sound full everywhere in the club. And again, depending on the size of the club and how far apart the PA mains are the mids and highs may or may not be affected by this separation as well.
anyway, if you're happy with a mixed rig, rock it and don't worry about science. but if you're not, this thread contains scientifically proven facts that may help you identify the problem. is there something so inherently horrible about that?
You'll have phase cancellation anytime you have more than one speaker. If the speakers are wired in phase, get a half wavelength difference in distance from your ear to the two speakers and they cancel. If the speakers are out of phase, they'll be cancelling at equal distances, and reinforce at half wavelength difference distance. This is what causes comb filtering between multiple drivers in a single cab, its the same thing going on between the speakers in multiple cabinets causing phase cancellation.
So don't think you can avoid it by using matching, identical cabs.
Mixing different cabs is way more unpredictable.
Stack the cabs vertically to minimize horizontal comb filtering, and if you like the way it sounds, go for it.
Randy
So don't think you can avoid it by using matching, identical cabs.
Mixing different cabs is way more unpredictable.
Stack the cabs vertically to minimize horizontal comb filtering, and if you like the way it sounds, go for it.
Randy
billfitzmaurice
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- Sep 15, 2004
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No.
And this discussion has to do with phase response, not pathway differential phase/time align issues that lead to combing. That's an entirely different matter and has to do with driver spacing, physical alignment and bandwidth, not whether or not mixed drivers are used.
.... and after it is all said and done that's the botom line.. and the only one that really matters..
I gotta say... I have learned so much about amps, cabs etc etc over the last 3 days...
Thanks to all of you...
Actually no. Speakers have time domain, distortion and phase characteristics as well as frequency response. A technically flat speaker may have crazy time domain or phase deviation.
(btw The human ear is sensitive to phase, but only to changes of phase.)
Also, everytime you use eq you are mangling your audio. The phase and time domain is screwed with, distortion is added and also ringing.
A speaker which naturally emphasizes bass freqs allows you to avoid eq.
Sorry to intrude here with what are perhaps stupid questions.
In regard to the phase issues, how well designed should a crossover be so that you can used a mixed setup? I mean, my preamp has an internal crossover with adjustable frequency but can I really rely on it?
In regard to the dispersion problems, lets say that I have two 2x10 cabs stacked vertically (witch is the ideal right?) but I need more power and so I'll add another "column" of two 2x10. How far appart would they have to be to minimize the dispersion issues?
On a side note, do you think EBS does not place their 10's side by side because of the dispersion issues?
In regard to the phase issues, how well designed should a crossover be so that you can used a mixed setup? I mean, my preamp has an internal crossover with adjustable frequency but can I really rely on it?
In regard to the dispersion problems, lets say that I have two 2x10 cabs stacked vertically (witch is the ideal right?) but I need more power and so I'll add another "column" of two 2x10. How far appart would they have to be to minimize the dispersion issues?
On a side note, do you think EBS does not place their 10's side by side because of the dispersion issues?
billfitzmaurice
Commercial User
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You can rely on it. But you would not use a crossover unless you have cabs specifically designed to operate in different bandwidths. AFAIK currently there are none on the market.
50 feet, give or take.
If two 2x10s aren't loud enough: PA.
There's only one reason not to place drivers vertically, and that's cosmetics. I don't see any EBS cabs with vertical drivers.
Just to clarify, are you saying that the [Invalid or Expired Link Removed] is not better than a traditional 4x10 or just that the vertical placement is WAY better alternative?
I'm going to revive this thread by asking the following:
If the delay is bigger, depending on the difference in speaker size, wouldn't there be a MASSIVE phase shifting going on between a 15" an it's inbuild tweeter?
If the delay is bigger, depending on the difference in speaker size, wouldn't there be a MASSIVE phase shifting going on between a 15" an it's inbuild tweeter?
This arrangement has a crossover, right? Did you see his comment about two drivers being designed to operate in different ranges? The other issue has to do with the type and placement of the crossover- if it's after the amp and passive, that adds changes to the phase response but if it's active and before the amp, it can be a steeper slope/phase corrected.
A 15" with a tweeter is a bad combo. The tweeter will start producing sound at a higher point than the 15" can produce without beaming.
A lot of common bass cabs don't lowpass the woofers at all, just let them run fuul out and they still can't reach to where the little bullet tweeters commonoy used start to pick up the sound.
Yes, passive crossovers introduce phasing issues that must be accounted for in their design. That's one reason some sound so much more "coherent" than others.
With respect to how the human ear/brain works, good alignment is obviously best, but, if the highs are leading the lows, arriving at the ear some few milliseconds sooner, we still percieve that as clear sound. If the lows lead the highs, it sounds more muddy, indestinct....not clear or coherent.
Yes, passive crossovers introduce phasing issues that must be accounted for in their design. That's one reason some sound so much more "coherent" than others.
With respect to how the human ear/brain works, good alignment is obviously best, but, if the highs are leading the lows, arriving at the ear some few milliseconds sooner, we still percieve that as clear sound. If the lows lead the highs, it sounds more muddy, indestinct....not clear or coherent.
I say use what you want, for no other reason other than the fact that it's what you want to use. Accept the pluses and minuses that come with using what you want, and you'll be fine. There is no ultimate solution that we should all be following.
Sheehan's using 3 of my amp heads (LH1000s), and 3 15s. One amp and woofer for highs, one for lows, and one for pedals as he says. With all of that I still ain't a fan of his tone haha.
My first rig was a 4x10 and 1x15. I ended up blowing the 15. I have always suspected that it was because I had the amp in bridged mode, which is more than double the wattage the cabs are rated for (they're older Fenders). The 4x10 still thumps to this day (amp still in bridged mode). I just haven't bothered to repair the 15 to test my theory. I enjoy the sound of my 4x10 alone, and my 8x10, and enjoyed my mixed cabs.
Sheehan's using 3 of my amp heads (LH1000s), and 3 15s. One amp and woofer for highs, one for lows, and one for pedals as he says. With all of that I still ain't a fan of his tone haha.
My first rig was a 4x10 and 1x15. I ended up blowing the 15. I have always suspected that it was because I had the amp in bridged mode, which is more than double the wattage the cabs are rated for (they're older Fenders). The 4x10 still thumps to this day (amp still in bridged mode). I just haven't bothered to repair the 15 to test my theory. I enjoy the sound of my 4x10 alone, and my 8x10, and enjoyed my mixed cabs.
Read every post in this old thread, and learned a ton, but still have 1 question! I am using WinISD to model different combos of mixed speakers and found you CAN get phase plots of mixed speakers to overlay if tuned properly, but not usually. My question is, how much phase offset between drivers is tolerable before audible? Particularly in that 40-150Hz region where phase is swinging a lot. 10 degrees? 45 degrees? Anyone done experiments with known speaker boxes or found a thesis on it? I assume the answer is at least as high as the speaker to speaker variability of a multidriver cabinet. Anyone know what that is?
