speaker cab questions

Rocks · #1 09-21-2010, 10:22 AM

I have an older Trace Elliot 1518-TP cab. It has a single 15" and two front ports. I can stand close to the cab and barely hear myself while people in the crowd are getting blasted by the volume. How far away do I need to be from the cab to hear it good? I always thought only bass reflex cabinets had this issue, was I wrong? And last but not least, I have port covers to close off the ports, will using these change the distance that I need to be to hear it? I can't really experiment as I can't crank the amp at home and we don't have another practice before our next gig. Any help would be great!

thatpaxguy · #2 09-21-2010, 12:05 PM

The sound waves from a bass take a longer time to complete a cycle, I remember something about having to be a good 30 feet or so for the full wave to develop and to hear exactly what its supposed to sound like. Naturally it depends upon the gear in question, but regardless, if you're within 10 feet as you would be on a stage, you're not hearing what they're hearing in the audience. It's best to make your sound somewhat "tinny" on stage, rolling off some of the bass that will develop by the time the cycle is completed and the audience will get the full effect.

Mo'Phat · #3 09-21-2010, 01:56 PM

Is the cabinet firing through your legs? Meaning: is the cabinet on the floor and at a low level? Could be that all the sound is just going under your ears.

One options is to tilt the cabinet back so it's pointing up at your head, or put it on a stool or something so it's at ear level.

You may be compensating for not being able to hear yourself due to the fact the speaker isn't directed at your ears.

Rocks · #4 09-21-2010, 02:02 PM

I thought you would lose a lot of the bass response if you take the cab off the floor. Tilting back isn't an option as the cab doesn't lend itself to that and my head would probably slide off too.

Mo'Phat · #5 09-21-2010, 02:07 PM

I suppose there is a trade off between losing floor coupling (perceived 'more bass' when cab is flat on the floor) and being able to hear yourself/not pummel the crowd with your lucious bass.

Something simple as a block of wood to lift the front of the cab about 2" would do three things:
1 - maintain floor coupling since the back edge of your cab is on the floor.
2 - elevate the firing angle of the speaker up above the heads in the crowd.
3 - be not such an extreme angle that your amplifier slides off the back.

Mo'Phat · #6 09-21-2010, 02:08 PM

...or you can stack another cabinet on top to get sound closer to your ears, and maintain floor coupling and a level cabinet.

Rocks · #7 09-21-2010, 02:11 PM

Quote:

Originally Posted by Mo'Phat

...or you can stack another cabinet on top to get sound closer to your ears, and maintain floor coupling and a level cabinet.

I do that for larger gigs, but smaller gigs I prefer to use one cab as its easier on my already bad back. Even with the two cabs I seem to be turning the audiences internal organs into pudding and still have a hard time hearing myself.

Mo'Phat · #8 09-21-2010, 02:35 PM

Another thing to try...on the acceptance that lower bass frequencies are omni-directional, is to turn your cab around or put it on the side of the stage facing along the stage, instead of firing right at your audience.

The only other thing I can possibly think of is bedroom vs. bar room equalization. At lower volumes, I tend to turn up my bass knob or sliders to get that subsonic boom and thump...but I don't really realize that it's shaking the walls at the other side of the house. I have to remind myself that when the volume goes up, the bass knob should go down. Bedroom vs. bar room. Turning down your bass will allow you to turn up the volume without pummeling the audience and you should be able to hear yourself better.

Pretty much what the first person to reply was saying.

Rocks · #9 09-21-2010, 04:42 PM

The funny thing is I am only using a 130 watt head. It's a Trace Elliot RAH130 and its bouncing bottles off club shelves with the EQ set fairly flat.

Mo'Phat · #10 09-21-2010, 04:49 PM

From my experience, TE 15's are pretty loud and efficient. They also have very tweakable EQ's, and 'flat' for that head doesn't necessarily mean all the sliders at zero. It may still be pretty colored.

Sartori · #11 09-21-2010, 04:51 PM

Quote:

Originally Posted by thatpaxguy

The sound waves from a bass take a longer time to complete a cycle, I remember something about having to be a good 30 feet or so for the full wave to develop and to hear exactly what its supposed to sound like. Naturally it depends upon the gear in question, but regardless, if you're within 10 feet as you would be on a stage, you're not hearing what they're hearing in the audience. It's best to make your sound somewhat "tinny" on stage, rolling off some of the bass that will develop by the time the cycle is completed and the audience will get the full effect.

Because you use 30ft. wide headphones, right?

billfitzmaurice · #12 09-21-2010, 08:52 PM

Quote:

Originally Posted by thatpaxguy

The sound waves from a bass take a longer time to complete a cycle, I remember something about having to be a good 30 feet or so for the full wave to develop and to hear exactly what its supposed to sound like.

Myth. How do you explain headphones?
OP, your problems are caused by three factors. The main factor is boundary cancellations close to the cab. There's not much you can do about that. The next factor is weak mids from your cab, the third is what mids you do have are passing you by at knee level. Without going to a different speaker about the best you can do is to tilt the cab back so you can hear what mids you have.

NateS · #13 09-21-2010, 09:02 PM

if you get the chance to at your next gig, before you start jump down and go out to the audience area and play, and have your band member change volume settings. Make it sound good out there, then come back and live with what you have.
Then, next practice, use that info, and try to find a better sound when you are closer.

Rocks · #14 09-21-2010, 09:05 PM

Quote:

Originally Posted by billfitzmaurice

Myth. How do you explain headphones?
OP, your problems are caused by three factors. The main factor is boundary cancellations close to the cab. There's not much you can do about that. The next factor is weak mids from your cab, the third is what mids you do have are passing you by at knee level. Without going to a different speaker about the best you can do is to tilt the cab back so you can hear what mids you have.

Are you referring to the speaker or the cabinet as being the problem? I forgot to mention that the original speaker has been replaced with a 400 watt celestion, does this make a difference?

Stick_Player · #15 09-21-2010, 09:11 PM

Quote:

Myth. How do you explain headphones?

You beat me to it!

How did this myth get started and have such a following of disciples?

billfitzmaurice · #16 09-21-2010, 09:26 PM

Quote:

Originally Posted by Stick_Player

You beat me to it!

How did this myth get started and have such a following of disciples?

Because boundary cancellation null zones close to the speaker make it seem louder when you get further away, though what's really happening is that further away you're no longer standing in a null zone. The disciples are those who knew what they heard but not why they heard it.

Quote:

Are you referring to the speaker or the cabinet as being the problem? I forgot to mention that the original speaker has been replaced with a 400 watt celestion, does this make a difference?

Fifteens have very weak mids off-axis, and if you've got a 1x15 that's not aimed up at your ears you are off-axis.

Rocks · #17 09-21-2010, 10:45 PM

Quote:

Originally Posted by billfitzmaurice

Fifteens have very weak mids off-axis, and if you've got a 1x15 that's not aimed up at your ears you are off-axis.

Would 10's be better?

Sartori · #18 09-22-2010, 02:07 AM

From what I've read on here, that depends on the configuration of 10"s.

If I'm remembering things right, placing speakers side by side decreases their horizontal dispersion. So, two vertically stacked 2x10" cabs would have good midrange dispersion, but a standard, square 4x10" would not.

billfitzmaurice · #19 09-22-2010, 06:30 AM

Quote:

Originally Posted by Sartori

From what I've read on here, that depends on the configuration of 10"s.

If I'm remembering things right, placing speakers side by side decreases their horizontal dispersion

And placing two tens vertically halves their vertical dispersion. That's why the 4x10 is the worst possible speaker topology, because it has limited dispersion on both axis. As with a 1x15 you can tilt a 4x10 back so that you can hear it, though that doesn't help the rest of the band or the audience. Vertically stacked 2x10s give the best possible result for you and everyone else.

Rocks · #20 09-22-2010, 08:26 AM

Quote:

Originally Posted by billfitzmaurice

And placing two tens vertically halves their vertical dispersion. That's why the 4x10 is the worst possible speaker topology, because it has limited dispersion on both axis. As with a 1x15 you can tilt a 4x10 back so that you can hear it, though that doesn't help the rest of the band or the audience. Vertically stacked 2x10s give the best possible result for you and everyone else.

Ok, you lost me here. I am assuming this is a mistake since the first sentence says 2x10s vertical halves their dispersion but the last sentence says its the best way to go.