Members snakum Posted January 10, 2006 Members Share Posted January 10, 2006 I just bought my first real bass amp today, a Peavey Basic 112, and though it seems to be loud enough for the kind of small-club gigs I play, I want to run one of my guitar cabs as an extension cabinet. The speaker in the Basic 112 is an 8 ohm PV Blue Marvel, whereas the speaker in my Classic 30's extension cab is a 16 ohm Blue Marvel (I run Weber Blue Dogs or Greenbacks in all my guitar amps). I'm not worrying about eventually destroying the 16 ohm Blue Marvel, because I have owned five Classic 30s and two Classic 50s and I have a room full of PV Blue Marvel speakers. I am worried about the amp, though. It is my understanding that a solid state amp can run a higher speaker impedance with no problems whatsoever, but that a lower impedance than specified can possibly cause expensive repairs. Correct? The Basic 112 has an 8 ohm speaker, the cab has a 16 ohm speaker, even though the math escapes me (8 and 16 splits for 12 ohms, total impedance?) it seems I will be fine. Am I missing anything? I should be able to run this until the speaker explodes from the low frequencies (I have plenty) or until I get my Mark VII or Firebass rig together, without damaging the amplifier, correct? Link to comment Share on other sites More sharing options...
Members Mudbass Posted January 11, 2006 Members Share Posted January 11, 2006 Your calculations are off just a tad. 16ohms + 8ohms = 5.3ohms. The Basic 112 was designed to operate at a minimum of 8ohms. Sorry, no extension speaker for you. Link to comment Share on other sites More sharing options...
Members snakum Posted January 11, 2006 Author Members Share Posted January 11, 2006 I knew sump'n was wrong somewhere. It's about the heaviest bass combo I can carry now that I'm old and feeble, but one won't be enough, even with an extension cabinet, on those nights when everything's clicking and the band keeps getting louder and louder. If I can find another one cheap, I'll run two until I can put together a pro rig. Have'n a blast with two less strings than usual. Link to comment Share on other sites More sharing options...
Members snakum Posted January 11, 2006 Author Members Share Posted January 11, 2006 No ... wait a minute .... The manual says an 8 ohm extension cab is needed to yield 4 ohms at 75 watts (50 watt without the ext cab), so with the extension speaker jack tapped, the power amp is looking for a minimum of 4 ohms, right? I'm so confused. Link to comment Share on other sites More sharing options...
Members megadan Posted January 11, 2006 Members Share Posted January 11, 2006 Originally posted by snakum No ... wait a minute .... The manual says an 8 ohm extension cab is needed to yield 4 ohms at 75 watts (50 watt without the ext cab), so with the extension speaker jack tapped, the power amp is looking for a minimum of 4 ohms, right? I'm so confused. That's right... if you're manual says you're cool at 4 ohms, then you're cool at 5.whatever, too Link to comment Share on other sites More sharing options...
Members snakum Posted January 11, 2006 Author Members Share Posted January 11, 2006 Oh, thank God. With the extension cab it will just barely be enough for what I'll be doing with it ... farting around ... small club gigs ... etc. Thanks. Link to comment Share on other sites More sharing options...
Members Mudbass Posted January 11, 2006 Members Share Posted January 11, 2006 Well somethin's screwy. The manual for the Basic 112 on Peavey's site makes no mention of an extention cab and in fact doesn't show an extension speaker out at all. http://www.peavey.com/support/searchmanuals/list/basic112.cfm Link to comment Share on other sites More sharing options...
Members snakum Posted January 11, 2006 Author Members Share Posted January 11, 2006 That's not the manual I have. Specs also in last year's Monitor magazine. Mine is the latest 'red print' version. 50 watts, with 75 watts at 4 ohms with external speaker. As I'm learning more and more about it, I think it will be plenty loud with a good extension cab. I have it rattling the windows here with my Classic extension cabinet. Peavey makes a matching 15" cab that out to do the trick nicely. Link to comment Share on other sites More sharing options...
Members i_wanna_les_paul Posted January 11, 2006 Members Share Posted January 11, 2006 Be warned - the C30 extension cab may not last long and may sound farty while it's busy killing itself. Just FYI. Dustin Link to comment Share on other sites More sharing options...
Members snakum Posted January 11, 2006 Author Members Share Posted January 11, 2006 LOL! It's a home-made jobbie with one of the many, many Blue Marvel speakers I have lying around installed in it. I won't mind killing one of them while I wait on the matching 15" Peavey extension cab. Link to comment Share on other sites More sharing options...
Members bassmanatlarge Posted January 11, 2006 Members Share Posted January 11, 2006 If you have 2 16 ohm speakers, running them together would create an 8 ohm extension cab. That 8 ohms combined with your combo's 8 ohms will give you 4 ohms. 2 8 ohm cabs will be better balanced sound wise. When you run an 8 and a 16, the 16 will be barely audible alongside the 8. Link to comment Share on other sites More sharing options...
Members Rhythmalism Posted January 11, 2006 Members Share Posted January 11, 2006 So long as you remember that's not a whole lot of wattage to share between multiple woofers. It's a fair fix for the short term . Link to comment Share on other sites More sharing options...
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