Bill Fitzmaurice

19 hours ago, Count Bassie said:

I think a sub is overkill. It fills the stage with super-low, mostly in-usable freqs,

True. While it seems to have a lot of low frequency content reggae bass isn't all that low, it's just loud. Most content is between 60 and 90 Hz. If it went much lower the Fridge wouldn't be the benchmark reggae bass cab.

Time was that bass cabs didn't go as low and loud as PA subs, but that's no longer the case. Cabs loaded with long throw high displacement woofers are just as capable. The trick is finding out which cabs are so equipped, as very few provide said information. Barefaced is one that does.

FWIW a high energy rock concert will measure 105 to 115dBC at 30 meters from the stage. Interestingly metal tends to measure no higher than other genres, because their guitar tones are highly compressed.

There's nothing wrong with mixing speaker sizes, if it's properly implemented, with separate driver chambers, drivers optimized for different pass bands and a crossover. That's SOP with PA cabs, with bass cabs not so much.

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We had a decibel meter at rehearsal last night and we topped out at around 100dB.

That's not loud at all, so I suspect you used an 'A' weighted meter, which doesn't measure low frequencies. A 'C' weighted meter is required to measure the full spectrum.

1 hour ago, Shiveringbass said:

Rear ported cabs are often seen as a bit more difficult to place on stage

'Seen' is the operative word. The back of the cab would have to be tight to the wall for there to be any audible effect, and that effect would be reduced low frequency output, not enhanced. However, if one sees the port is on the rear and thinks as a result that it will make a difference confirmation bias kicks in, and as a result it will be heard. 🙄

Port radiation is 360 degrees, so it doesn't matter which direction it's aiming. As for tone clarity, that's sourced in the mids and highs. Ports don't radiate mids and highs.

2 hours ago, SteveXFR said:

 What waste reason for the design?

An isobaric configuration reduces the cabinet size required to realize a desired low frequency response. For those of you who know what T/S specs are the Vas is halved compared to one driver, and therefore so is the cabinet volume exclusive of the space taken up by the second driver. The downside is that the cone displacement exposed to the air, T/S spec Vd, is the same for the two drivers as it is for one, so maximum output is the same as with one driver, albeit from a smaller cab. Isobarics were somewhat logical decades ago, when Vas values of 600 liters weren't unusual, making cabs capable of going low really huge. Since the drivers used in the Orange have a Vas around 150 liters the size advantage gained isn't that much, and as you've found it doesn't go nearly as loud as a standard 212, by 6dB to be precise.

On 22/01/2022 at 06:56, mybass said:

Speaker design and tech has probably moved forward in some areas quite a bit.

Not all that much in the last 15 years. The last significant tech change was to neo magnets, which allowed improvements in excursion without sacrificing sensitivity, and as a result higher output than previously possible. Most of the major alterations that neo allowed came circa 2004-2008. There have been further refinements since then, but nothing earth shaking or trouser flapping. 

The BF displacement is 250cc. Markbass? Who knows? Where bass output is concerned it's just like horsepower from an engine, there's no replacement for displacement.

There are tens that can handle a lot more, but to do that they sacrifice midrange response, so they're typically used in subwoofers or designs with separate midrange drivers. On the flip side guitar tens that will go into high distortion with only ten watts are common.

5 hours ago, Tdw said:

Thanks, I thought that might be the case. I don't suppose you've any idea about x max for the barefaced and the te 10 inch drivers?

The BF ten has 250cc of displacement, indicating around 7.5mm xmax, which is very respectable. I don't see it handling less than 225w. The TE driver is an unknown commodity. It supposedly uses an Eminence Neo Ten, but they make at least four different varieties, and that doesn't count OEM variants.

They're just examples of how far apart drivers can be in their mechanical capability, which is defined by xmax. By no means are these differences rare. One of the most ubiquitous drivers is the Eminence Beta 10, and OEM versions of it. Orange uses it in their OBC 410. It reaches xmax at 40w at 80Hz, where the output demand for electric bass is at its highest.

3 hours ago, acidbass said:

Maybe from a scientific perspective it isn't 'correct' but to me what's correct is what sounds good

When you have one driver that can only take 50 watts before reaching its mechanical limit and another that can take 500 watts before reaching its mechanical limit you don't need a scientific background to see that it's a bad pairing. It's not about being correct, it's about being logical.

Don't mix different cabs. If they're not identical, most especially if the drivers aren't identical, you're creating a weak link in the chain scenario.

31 minutes ago, jay42 said:

 in my mind if I went for 4 Ohm cabinets I could utilise full power from the amp

Divest that notion. It's the rare cab that can make use of more than half its rated thermal input power before running out of the mechanical ability to use it, so the oft mentioned quest of 'getting all the watts out of my amp' is right up there with the search for the Holy Grail or an honest politician of things not worth the effort.

Cabs don't hiss, or create any other noise. They will reproduce hiss and/or noise present in the signal chain, which starts with the pickups and ends at the amp output jacks.

What you'll end up with is a blown 4 ohm resistor. If you must use a second cab make it identical to what you have now. If your amp won't handle a 2 ohm load you'll need a break out box to series wire them.

4 hours ago, BassmanPaul said:

It's how I would have wired it but I would have performed a battery test to verify which terminal is the positive on the driver.

That wouldn't tell you which wire was which. If anything the white wire is probably chassis ground, assuming there is a chassis ground. Being an older amp it most likely has a chassis ground, but that's not the case with many micro amps. 

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If you only use the combo on its own i.e. without an extension cab then it doesn't matter which way round you connect it.

Quite right.

1 hour ago, Dan Dare said:

Aw, go on Bill. It will be entertaining.

Discussing driver size is like hitting yourself upside the head with a hammer. It feels really good when you stop. 😉

So 2022 starts off with deja vu, and not in a good way. Getting sucked in this time I am not. 🙄

Anything Marshall. What with the pandemic lots of gear has made its way into pawn shops and onto EBay, so prices should be down. For instance: https://www.ebay.co.uk/itm/255281994107?hash=item3b6ffe197b:g:aGUAAOSwNZ9humOJ

That. While the tops need to go to the left and right front the subs can be stuck out of the way, because on the one hand their output pattern is omnidirectional, while on the other not directionally locatable.

It's easier to hear the sound of the cab up close more like what's heard at a distance when there's no short ceiling or side walls on the stage. Those can cause boundary sourced low frequency null zones close to the cab, killing the lows if you're standing in one of those zones. Those zones go away the further you are away from the cab, explaining why the lows can sound much louder out in the audience than on the stage. This phenomenon lead to the myth of wave propagation, the notion that a wave can't be fully heard until one is a certain portion of a wavelength away from the source. Like most myths it was a seemingly plausible explanation for an observed result arrived at because the true explanation was unknown.

There's a big difference between the 3dB sensitivity increase you said was realized from each boundary and the 6dB that's actually realized. You're not going to get any increase by putting a cab on the floor compared to your chart because your chart already reflects the result with floor placement. I didn't mention flush mounting because it's not pertinent to this discussion. Placement some distance in front of a wall does not lead to comb filtering. It does result in an Allison Effect response notch, which I could have put on that chart, but that would be making things more complicated than necessary for this particular thread. What matters as far as boundary loading is concerned is that it will not turn a well executed ported cab into a boom machine, nor will turn a thin sounding sealed cab into a low end monster. Most of the inherent characteristics of both will be maintained, but they'll be louder, which is seldom a bad thing. Just by being louder they'll seem to go lower, as that's part and parcel of how our hearing works.

The boost is greater in the lows. That's not the same as only in the lows.