Speaker resistance for a solidstate amp?
Moderator: Shoshanah Marohn
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Larry Robertson
- Posts: 222
- Joined: 5 May 2006 12:01 am
- Location: Denver, Colorado, USA
Speaker resistance for a solidstate amp?
I've got a little Fender Frontman 25 for a practice amp and it has a 10" cheap speaker in it marked 8 ohms. I found a 12" speaker from a Blues Junior and have an extension cabinet for it. It is also 8 ohms. So I know I could run the 12" 8 ohm speaker instead of the 8 ohm 10" speaker. But, is there any way to use them both? I know enough about resistance to know that if I wire two 8 ohm resistances in series that would be 16 ohms resistance, and if I wire two 8 ohm resistances in parallel I'll have 4 ohms resistance. What effect would either 4 or 16 ohms resistance load on the amplifier output be and would either one cause damage to a solid state amp? Thanks, Larry Robertson, Denver
Website: www.Music2myEars.net
MSA D-10, Carter U12, Fessy SDU-12,Emmons P/P D-10, Emmons P/P U-12,Emmons S-10 ShoBud SuperPro, Lap steel, keyboards, 6-string Guitars.. too many
MSA D-10, Carter U12, Fessy SDU-12,Emmons P/P D-10, Emmons P/P U-12,Emmons S-10 ShoBud SuperPro, Lap steel, keyboards, 6-string Guitars.. too many
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Les Cargill
- Posts: 774
- Joined: 1 Jan 2014 7:09 pm
- Location: Oklahoma City, Ok, USA
You can't *reliably* run them both. 8+8 never equals 8 when mixing speakers. The amp might be fine @ 4 ohms. but the only way you'd know it wasn't fine was when the little blue smoke got out.
Most SS amps are voltage devices. 4 ohms is twice the current of 8 ohms for the same voltage. Twice the current means twice the heat. Twice the heat means the little blue smoke can get out.
(the little blue smoke is the magical thing that keeps electronics working. When it escapes, they stop working ).
You can possibly run them in series : - from amp to - on one speaker, + on that speaker to - on the other, + from that speaker back to + on the amp : but it's likely to sound bad and will not use the amp as well as one speaker. But you never really know; sometimes it works out fine.
Most SS amps are voltage devices. 4 ohms is twice the current of 8 ohms for the same voltage. Twice the current means twice the heat. Twice the heat means the little blue smoke can get out.
(the little blue smoke is the magical thing that keeps electronics working. When it escapes, they stop working ).
You can possibly run them in series : - from amp to - on one speaker, + on that speaker to - on the other, + from that speaker back to + on the amp : but it's likely to sound bad and will not use the amp as well as one speaker. But you never really know; sometimes it works out fine.
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Rick E. Jackson
- Posts: 29
- Joined: 8 Jun 2007 2:30 pm
- Location: New Jersey, USA
Larry, I have the same amp. Best bet is to put a better quality 10 inch 8 ohm speaker in it. You'll be pleased the the results! Just verify all of the size measurements of the new speaker, it's a small box that it has to fit in. That particular amp is light duty and designed for an 8 ohm load. As Les pointed out, running at 4 ohms may cause component
breakdown.
breakdown.