T48 Anecdote

[Bill Fitzmaurice]

As long as there's no phantom power involved, you can also build an adapter to reverse the positive and negative wires (pin 2/3) on the mic cable. Hosa (and I'm sure others) sell this as a premade piece too.

Phantom is typically carried on pin 1/shield.

Phantom + is on both pins 2 & 3, - on pin one. That way a dynamic mic cartridge output, which is wired to pins 2 & 3, sees the same positive voltage on both pins and no current flows through it. With the same voltage on pins 2 & 3 the polarity of those can be switched without affecting anything other than phase.

[BrentEvans]

I still make it a point to keep phantom off when doing polarity reversals with adapters or dongles due to the fact that I once fried a piece of gear doing so due to a faulty phantom supply.

[brodave2]

How do you reverse polarity on the vocal channels?[

With the channel phase/polarity switches. This of course requires that the board be so equipped.

if the board doesn't have polarity switches on the channel strips, you can do the same thing with a mic cable, switch pins 2 & 3

[brodave2]

assuming power is not a concern, how would 3 - 24.5" T48 compare to 2 -30" T48, all with 3015 driver. I seems to me that the optimum T48 is 24.5", considering portability, response, etc. As far as center clustering, many stages I work are less than 24", so even a 24.5" T48 wouldn't work centered up. The few times I center clustered the T48's, the artist complained of too much bass on stage. It did sound great in the audience though.

[Bill Fitzmaurice]

As far as center clustering, many stages I work are less than 24", so even a 24.5" T48 wouldn't work centered up. The few times I center clustered the T48's, the artist complained of too much bass on stage. It did sound great in the audience though.

Clustered subs don't have to be centered. You're better off having them to one side where they can be wall loaded rather than centered where there is no wall to load them.

[gdougherty]

assuming power is not a concern, how would 3 - 24.5" T48 compare to 2 -30" T48, all with 3015 driver. I seems to me that the optimum T48 is 24.5", considering portability, response, etc. As far as center clustering, many stages I work are less than 24", so even a 24.5" T48 wouldn't work centered up. The few times I center clustered the T48's, the artist complained of too much bass on stage. It did sound great in the audience though.

I'd guess you may have better low end response with the 30", but you'll be able to move more air with the three 3015LF giving a higher final output, especially above 60Hz.

[brodave2]

assuming power is not a concern, how would 3 - 24.5" T48 compare to 2 -30" T48, all with 3015 driver. I seems to me that the optimum T48 is 24.5", considering portability, response, etc. As far as center clustering, many stages I work are less than 24", so even a 24.5" T48 wouldn't work centered up. The few times I center clustered the T48's, the artist complained of too much bass on stage. It did sound great in the audience though.

I'd guess you may have better low end response with the 30", but you'll be able to move more air with the three 3015LF giving a higher final output, especially above 60Hz.

Okay, so the horn mouth area is bigger with 3 - 24.5" titans, so wouldn't that take it lower?

[Bill Fitzmaurice]

Okay, so the horn mouth area is bigger with 3 - 24.5" titans, so wouldn't that take it lower?

Yes, though not by much. Most of the advantage would come from the extra power handling and displacement of three drivers versus two.

[gdougherty]

Bill, does the larger chamber on the 36" account for some of the low end extension seen in the 36" chart? Would a wider cab not retain some of that advantage, or does it all effectively disappear as you take the cab wider?

[Bill Fitzmaurice]

Bill, does the larger chamber on the 36" account for some of the low end extension seen in the 36" chart? Would a wider cab not retain some of that advantage, or does it all effectively disappear as you take the cab wider?

There is a point beyond which there are diminishing returns, 36" is it. Improvement above 35Hz is attributable to the larger horn, not the larger chamber.

[gdougherty]

Bill, does the larger chamber on the 36" account for some of the low end extension seen in the 36" chart? Would a wider cab not retain some of that advantage, or does it all effectively disappear as you take the cab wider?

There is a point beyond which there are diminishing returns, 36" is it. Improvement above 35Hz is attributable to the larger horn, not the larger chamber.

Good to know, I'll have to go back and look at the multi-cab charts. I'd recalled not seeing as drastic a difference in response shape between a 1 & 2 cab response as you see between a 24" and 36" T48 on the single cab comparisons.

[quaizywabbit]

too bad there isnt a response chart showing the percentage of people made sick up front, or how many pitchers of beer dance off the tables, fallen ceiling tiles....etc