Bill Fitzmaurice

Tweeters don't hiss. Amps do.

It doesn't. But the extension should be ported as well in any event.

1 hour ago, Phil Starr said:

The ampeg gets away with it because standing a cab on the floor reinforces the bass at the lowest frequencies. The floor reflections add to the bass coming from the speaker so the reflected bass fills in the missing bit.

That's true of all speakers, and so long as they're less than 1/4 wavelength off the floor it still applies. I/4 wavelength is 86cm at 100Hz, 172cm at 50Hz. The same applies to the distance from the baffle to the wall behind the cab. This does bring up another point. If you have boom you can reduce it by lifting the cab high enough and/or pulling it away from the wall far enough. In effect you can utilize the cab height off the floor or distance to the rear wall as a notch filter. As to cabs being too bass heavy at gigs it's often for the same reason. You can have a combination of cab to ear to boundary distances that result in cancellations of the lows where you're standing. Move away and the distances are longer, cancellation frequencies shift downward to below the range of the bass, and magically it's louder and deeper ten meters away from the cab than it is at two meters. Just another tidbit that guitar players need not be concerned with, but bass players must. 

Yes, but refrigerators tend to be between 38 and 40F, so as not to freeze anything. My mother told me when I was a baby our refrigerator, in winter anyway, was a peach basket perched on a stand outside the kitchen window. It's going to hit 50F here tomorrow, then back down to the 20s on Sunday. We're usually around 10 degrees higher than Toronto, 10 degrees lower than Boston.

For sure OP keep an eye out for refrigeration. Commercial units are notorious for creating a mess of the AC, even when on different branch lines.

48 minutes ago, asingardenof said:

Markbass does a 3x10 cab that apparently runs at 6 ohms. Presumably they're just rounding up from 5.3? Or is an 18 ohm driver feasible?

Probably rounding it up. That's OK, because nominal driver impedance ratings are just that, nominal, not exact.

You'll get the best result with another cab loaded with the exact same driver. Otherwise you're creating a chain with a weak link. Comb filtering has nothing to do with the driver sizes. It happens in the highs when drivers are placed side by side. Doing so also halves the horizontal dispersion in the mids compared to a single driver, or multiple drivers vertically stacked.

Three 16 ohm drivers would give 5.3 ohms, which is as low as one really needs. That's no problem with OEM, but at retail there aren't many 16 ohm drivers to be found.

2 hours ago, fretmeister said:

 adding a resistor or 3 rather than redesigning the speakers themselves to be 12ohms each. Anyone know?

Resistors won't work, they lose too much power and get too hot. 12 ohm voice coils aren't a problem for OEM, you just have to meet the minimum order requirement. With Eminence that's 50, although I can't see anyone order fewer than 100.

Oh, I always replied similarly when my wife said something. But I never actually heard what she said. It was just a defense mechanism against her repeating herself. 😉

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The Markbass Tilt Stand arrived today. A quick try with the BF One10 at low volume suggested it might just work.

I didn't notice where you were ordering it, so this advice is late, but this or something similar would do much better:

https://www.sweetwater.com/store/detail/AmpStd--on-stage-stands-rs7000-tiltback-amp-stand

I'd think it's cold enough there to put much of it outside. Not frozen, of course, although I could have done that last week.

1 hour ago, BassmanPaul said:

For me, I wouldn't play through an 8x10 if you gave it to me!

I wouldn't, since my 112 goes as loud as a '69 SVT 810 would. 😉

It's a form factor that we really haven't needed for some thirty years now, thanks to both driver technology and PA. It remains the staple backline rental cab, since you won't find anyone who can rightly say that it's inadequate.

3 hours ago, Downunderwonder said:

I wouldn"t mind betting there are more lows available from the 410 than the 215.

It's certainly possible. How low or how high a driver will go isn't determined by its diameter.

45 minutes ago, PeterJohnson1 said:

"Don't bi-amp when both speakers are operating in the same frequency range. ......" Then why does the concept of bi-amping even exist?

When you have one speaker that's optimized for use in the lows and one that's optimized for use in the highs. Electric bass 410s and 215s are not. They're both full range.

I saw that, but separately powering isn't bi-amping. I said 'you may' as one amp may suffice, if the impedance load isn't too low,

2 minutes ago, Jakester said:

Well, we're back there at the end of the month so will check again and see. If it does it again in that location in the hall, I may need to invest in a VERY long extension to reach the sockets over the other side of the hall!

That could make things worse. Ground loop noise intensity is increased as the length of the ground wire is increased. Worse, it varies by the square of the wire length. Doubling the wire increases noise by a factor of four.

On 03/02/2023 at 06:17, Huge Hands said:

Funnily enough it was Mrs HH who persuaded me to have the test - she is sick of repeating herself when talking to me.

That, along with the rest, indicates you might have issues with midrange. In ear may not help unless you have EQ capability to boost the mids, for added intelligibility. As for the Missus,  IMO they shouldn't use female voices for GPS, as I'm genetically programmed to ignore them.

Don't bi-amp when both speakers are operating in the same frequency range. Chances are your Trace 410 goes if not just as low then almost as low as a 215. You might want to separately power the 215, for independent volume and EQ control, but you wouldn't use a crossover. Where bi-amping would make sense is using a 110 with a 215, and then only if the 110 is loaded with a guitar driver.

3 hours ago, SamPlaysBass said:

 I do worry about putting a big SVT on top of a couple of 2x10, although I could just leave it on the floor and save the backache of getting it up there in the first place. 

It saves your back and gets the cabs even higher, which is a good thing. 😉

3 hours ago, fretmeister said:

ported- more boomy bang 

sealed - less boom more gronky grindy squidge 

Not necessarily. Boom occurs in the 80-120Hz range, an octave above pant flapping lows. Ported cabs can be boomy, if they use drivers that don't have specs that are tailored for ported and/or the cab is tuned too high and/or it's too small. If anything sealed are more likely to have a response bump in the 80-120Hz range, while dropping off like a cliff below 80Hz. If you're used to the thin lows of sealed and prefer it that's fine, but where economy of size is concerned a pair of ported 2x10 will equal the low end output of a sealed 8x10, while you can cut back the lowest octave with EQ if that's your preferred tone. What you can't do is to boost the low end of a sealed cab with EQ to get those trousers flapping, as the drivers will run out of excursion.

27 minutes ago, SamPlaysBass said:

 I was wondering if by the magic that Alex manages to cram into them they achieve the same ear-level monitoring as an 8x10?

 

A pair of vertically stacked 2x10 will.

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Also, as much as I hate to ask as describing sounds is so much more difficult than actually hearing them for yourself, but what sonic differences are there between big sealed and ported cabs? 

Sealed don't go as low. Where the bottom end is concerned a pair of ported 2x10 will match a sealed 8x10. 

If it was good before and isn't now something's been changed. Find out what and you'll probably solve the mystery.

The leads me to believe a bad ground on the mains, or massive interference from either florescent lighting ballasts or refrigeration compressors. 

Power conditioners don't do much, if anything. The best method of power conditioning is to rectify the AC to DC, then remove any ripple with filtering capacitors. The thing is that's what your amp power supply does. Besides, noise isn't necessarily on the AC line. It might be airborne RFI or EMI. You mention having a complicated set up. That could be introducing ground loop noise. First things first, run the amp with nothing plugged in. If there's no noise that rules out the AC mains. Then just the bass. If there's no noise that rules out RFI and EMI. Then add the effects. If noise results it's probably a ground loop. There's also the possibility of a bad ground on the AC mains. It's a good idea to carry a plug in mains tester to be sure it's not dodgy.

Make a cardboard box the same size as the cab to test it.

1 hour ago, Jaybeevee said:

not getting past 11 o'clock  on the master without clipping seemed like an issue, especially as it was (although quite loud) not loud enough to keep up a loud drummer.

It's an issue, but not one necessarily caused by the pot. The total voltage gain from pickup to speaker starts with the pre in your bass and ends with the output stage of the amp, with every gain and EQ stage in the chain making its own contribution. Google 'gain staging'.

That said, you've got the effect of the pot backwards. Assuming you have a linear pot wide open versus at half the attenuation at the halfway point is -3dB. That's audible, but just. It's not half volume, which is -10dB. A log taper pot at half is -10dB compared to at full. Therefore the linear pot goes louder earlier in its rotation, not later. Some amps did so on purpose, so that someone trying one in a shop would be impressed at how loud it got at, say, a setting of 3. They wouldn't have been able to realize in a shop that anything past 4 didn't get any louder. 🙄