Bill Fitzmaurice

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. 🙄

1 hour ago, Jaybeevee said:

I think in this case it does. 

Most assuredly it does not. Power output depends on a number of factors, starting with the voltage output and frequency response of the bass, ending with the actual impedance of the speakers, which isn't a constant. It varies with frequency. This is a plot of the power output of an amp across the frequency spectrum into a typical 8 ohm twelve in a ported enclosure, driven with 28.3v, which is nominally 100 watts. There's nothing linear about it. This, BTW, is why loudspeaker engineers don't deal in watts. We deal in volts, which are a constant into any impedance load.

I didn't miss it.

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If being where you were also put the cab on axis with your ears as it always should be the mids and highs would have been louder and more clear as well.

2 hours ago, Huge Hands said:

 I believe what I was hearing (or not) could have been down to comb filtering effects caused by having mismatched driver sizes.  

That wouldn't be caused by the different driver sizes but by different phase responses. At frequencies where they differ at or close to 180 degrees apart they cancel. This scenario is one reason why well engineered systems never use different drivers in the same passband. Comb filtering is a related effect. It's when wave fronts from multiple sources meet at or near 180 degrees apart causing cancellation notches that alternately occur and disappear as one goes across the sound field. The primary cause is placing drivers side by side. The easiest cure is don't place drivers side by side. If you must do so the fix is to low pass one driver, or one side of a 4x,6x or 8x cab, so that they only work in tandem in the lows where comb filtering doesn't occur, and not in the mids and highs where it does. It's a simple inexpensive fix, known as an x.1 alignment, that's been used for at least fifty years by PA designers. AFAIK the only bass cabs that use it are Barefaced.

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What really opened my eyes, and ears, was a gig in a stall venue before Christmas, where a couple of ladies from the audience wanted to sing, so I sat on a stool in front of my rig and played,  the difference in what I could hear was pleasantly staggering.

What happened there was you had a boundary reflection sourced low frequency cancellation zone on stage, where you were close to boundaries. Out in the audience away from those boundaries you don't have those cancellations, so the lows are louder there. If being where you were also put the cab on axis with your ears as it always should be the mids and highs would have been louder and more clear as well. The cure is to do your sound check listening out in the audience, adjusting both volume and EQ accordingly. Whatever that results in on stage you live with.

4 hours ago, Phil Adams said:

firing straight at my bum!

That's why you can't hear it. Why do you think the monitors are tilted upward?

1 hour ago, Jaybeevee said:

This particular amp is made or fitted with linear pots. Where as most amps deliver more power in the early part of the volume sweep, and much less in the later, this amp delivers a linear power based on the pot adjustment.

Seems like a good idea, but our hearing isn't linear with respect to power. It's logarithmic, requiring ten times the power to sound twice as loud. That's why logarithmic taper pots are used for volume controls. They may not be linear, but they sound linear.  

1 hour ago, JPJ said:

Sorry Bill, 

I should have been clearer in my post. I have several preamps (both pedal and rack mount) that I tend to run into the return of my amp, hence thinking of a built-in poweramp in a single cab solution.

In that case...there's Powersoft if you've won the lottery. Otherwise just search. Just be sure it's full range, not a low passed sub amp. Sub amps are very inexpensive, as they don't need low THD specs and other attributes because they don't operate where they're an issue. 

IMO a better option is to make the cab an airhead, with an integrated space for a rack mount amp that are abundant.

1 hour ago, JPJ said:

“is there a simple plate amp module including power supply suitable to build into a bass cab”? 

Not that I know of. Those I'm familiar with don't have a pre-amp and tone controls that are suitable. You'd still need that in a separate package or pedal.

Even worse, multiple sources playing low frequencies may cancel each other. Besides, what you don't need from monitors is lows. You need mids and highs, especially if your backline isn't aimed at your ears and the mids and highs from it are passing you by below the belt.

1 hour ago, Jaybeevee said:

Thanks, that's something new for me. Unfortunately, not supplied with a manual, and the manufacturer is not answering me specifically on this point.

You can find third party sources for manuals for most amps. Google ' *** amplifier manual'.

It depends on where the lamp is wired to the circuit. Clipping can take place at every stage of amplification, from the input to the output. The manual should say. In general minimal clipping takes place when the master is on full, with the pre volume low.