Ohm my god
March 13, 2011 12:52 PM
The bass player in my band has this combo amp. It has 2 internal speakers, and an external speaker jack rated for a minimum impedance of 4 ohms. If he wants to hook up an additional cabinet, what does the impedance of the extra cab need to be?
He bought a Mark Bass 2x12 extension cab rated at 8 ohms. We plugged it in, everything sounded fine, but then we got...a smell.
He has a regular amp tech who assured him this setup would be fine but as this was the first run it made us a little squeamish.
I guess it's not clear whether that 4 ohm impedance includes the existing, internal speakers, or is just a standalone value. If his existing speakers already resist at 4 ohms, then the additional cab needs to be...what? I understand there's a formula to this, but if the info I found here is correct (under 'Calculating Total Impedence of Different Impedance Cabinets')...then there is nothing you can add to an existing 4 ohm load that will result in anything but a fraction of 4 ohms. If anyone's familiar with hooking up a cab to this particular amp and not frying any of the components involved, that'd be great.
He bought a Mark Bass 2x12 extension cab rated at 8 ohms. We plugged it in, everything sounded fine, but then we got...a smell.
He has a regular amp tech who assured him this setup would be fine but as this was the first run it made us a little squeamish.
I guess it's not clear whether that 4 ohm impedance includes the existing, internal speakers, or is just a standalone value. If his existing speakers already resist at 4 ohms, then the additional cab needs to be...what? I understand there's a formula to this, but if the info I found here is correct (under 'Calculating Total Impedence of Different Impedance Cabinets')...then there is nothing you can add to an existing 4 ohm load that will result in anything but a fraction of 4 ohms. If anyone's familiar with hooking up a cab to this particular amp and not frying any of the components involved, that'd be great.
Yup your setup is fine. The speakers internally run at 8ohms so you can use an 8ohm extension cab.
I found someone with a similar question on talkbass. A direct response from ashdown:
"To answer your questions enclosed. full power is realized into 4 ohms, the internal speakers are wired to 8 ohms therefore giving the opportunity to use an 8ohm extension. the amp puts out approx 300 watts into the internal speakers. The unit has the 1/4" jack socket on the rear for the internal speaker, but it also has a speakon connector for an extension cabinet."
posted by zephyr_words at 1:52 PM on March 13, 2011
I found someone with a similar question on talkbass. A direct response from ashdown:
"To answer your questions enclosed. full power is realized into 4 ohms, the internal speakers are wired to 8 ohms therefore giving the opportunity to use an 8ohm extension. the amp puts out approx 300 watts into the internal speakers. The unit has the 1/4" jack socket on the rear for the internal speaker, but it also has a speakon connector for an extension cabinet."
posted by zephyr_words at 1:52 PM on March 13, 2011
This thread is closed to new comments.
I'll take a look at the stats on all the gear but on quick review it looks fine.
posted by zephyr_words at 1:38 PM on March 13, 2011