2x15 rig question

[Dustin Teel]

I recently purchased the Acoustic B200 1x15 combo, with which I am very pleased. Great tone, and very loud.

I would like to add the Acoustic B115 cab to it for a full 2x15 rig. However, I am concerned because another bassist told me that the extension jack on the B200 is wired in series and, therefore, when a cab is added, the power rating drops, so I may not hear an increase in volume. Is this true??

It seems to me that two 15" drivers realizing 50ish watts would still be louder than one 15" driver of the same type seeing 200 watts. Is this not correct?

Any professional advice would be greatly appreciated, as I am not going to buy the cab if it would not result in a significant increase in volume and fullness.

Thanks ahead

[RickenBoogie]

It's true, add another cab, you'll lose some wattage. BUT, 2 15's should sound better than 1. Maybe not alot louder, but some louder.

[s_mcsleazy]

boogie said it better than i could have

[sokolasty]

EDIT:
You win 3 db due to 2 times loudspeaker surface

I also assume, that you could not crank up the volume without extension cab due to speaker excursion, now with the cabinet you can use twice as much power. Another +3db
But if one speaker is able to use whole power of your amp (which is doubtful), then you lose 2db instead of gaining 3dB.

You win from 1 (hardly audible) to 6dB (audible).

[will33]

Closer to the 1. You would however get a speaker up closer to ear level, making it much easier to hear yourself. It'd also narrow vertical dispersion by half. That means more sound being directed forward, towards you and the audience and less playing to the ceiling. All in all, it's some net gain, just not as much as if you could do all that AND increase power, or at least not lose any.

[sokolasty]

http://www.acousticamplification.com...115-Manual.pdf

According to manual (p. 9) extension cab jack is wired in paralell. All your concerns (regarding this case at least ) should go away.

[Dustin Teel]

Ahh, I see. Thanks a ton!! I guess the guy that told me this was mistaken. Also, I bought the amp used, so I had no manual.

Looks like I will be buying the B115.

Thanks again

[will33]

I've read the series thing somewhere as well. It might be something they changed in earlier / later models. Either way you can still run the extension and still gain something.

[RickenBoogie]

Yup. If it's been changed to a parallel connection, it's news to me. If the op has a brand new combo, then *maybe* it's parallel, but from their inception until not long ago, it was a series connection. Still, +1 to it being worthwhile either way.

[Dustin Teel]

The serial number is MFI1101. Anyone know how to date the amp? I registered it on Acoustic's site, but didn't see a way to find the manufacture date of the unit.

Any ideas?

[will33]

I don't know how those are put together inside. Sometimes you can just open it up and look at the jacks but that one will have the internal speaker wired directly with a single extension jack that's maybe mounted on a circuit board, pretty hard to tell that way.

You'd have to open it to find out but if contacts are exposed enough to get meter leads on, with the amp off, you could just plug any old speaker in the extension jack and see if your meter reading goes up or down.

Wouldn't really know any other way to find out if you can't date the serial number. Maybe call Acoustic and see if somebody there can look it up off the serial number.