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Topic: ext, speakers, |
Lewis John Foote
From: Dorset, UK
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Posted 26 Mar 2008 4:35 am
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howdy, any uncomplicated ideas, how to take an extention of my bandit, or nash,400, to run my 15, inch, horn, and ported cab,at, 8, ohmns, thanks, lew. _________________ pro1,s two round fronts, one square front, sho-bud, S12, LDG,1977, built by paul franklin sen, [THE PROFESSIONAL]nice all original, bandit65, nash, 400, profex 11,match-box, 7A,DD3, delay,various accoustic guitars, amps, and other necessitys, |
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John Roche
From: England
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Lewis John Foote
From: Dorset, UK
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Posted 26 Mar 2008 6:23 am
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howdy, mick, the bandit is 8ohmn, my cab is 8 ohmn, the bandit speaker is , a 12inch, scorpion, the connectors are of the beyonet type, with spare blades to take ext,if i joined these as there flowing, to a JACK PLUG INSERTED INTO the back of the body of the amp, so i just have a external jack connection, is that suffice, i looked at diagram, would feel safer taking some ones word for it , not puttin you under any sort of liabilty, if things went wrong, thanks, lew. _________________ pro1,s two round fronts, one square front, sho-bud, S12, LDG,1977, built by paul franklin sen, [THE PROFESSIONAL]nice all original, bandit65, nash, 400, profex 11,match-box, 7A,DD3, delay,various accoustic guitars, amps, and other necessitys, |
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Lewis John Foote
From: Dorset, UK
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Posted 26 Mar 2008 6:26 am
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howdy, mick, sorry i forgot mention , nash,400, is at 4 ohmns, lew. _________________ pro1,s two round fronts, one square front, sho-bud, S12, LDG,1977, built by paul franklin sen, [THE PROFESSIONAL]nice all original, bandit65, nash, 400, profex 11,match-box, 7A,DD3, delay,various accoustic guitars, amps, and other necessitys, |
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John Roche
From: England
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Posted 26 Mar 2008 7:09 am
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Lew, to connect two speakers of the same ohmage you need this setup,
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Larry Robinson
From: Peachtree City, Georgia, USA
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Posted 26 Mar 2008 7:26 am
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I have a Bandit 65 with Scorpion speaker and NO external speaker jack. To connect an external speaker, use parallel connection, connect pos + from one to the pos + on the other. Do the same for the neg -. the impedance will then be 4 ohm and the power out will drop. |
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Lewis John Foote
From: Dorset, UK
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Posted 26 Mar 2008 7:41 am
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howdy, dont know why i addressed you as mick, sorry john, lookin at the diagram, you sent, it looks , under standable, with both speakers in the same cabinet, but with the other speaker and horn in the other cab, im not visualising the connection, i have the jack out of the other cab, i just need a jack out from the live amp, i dont seem to be under standin, it, lew _________________ pro1,s two round fronts, one square front, sho-bud, S12, LDG,1977, built by paul franklin sen, [THE PROFESSIONAL]nice all original, bandit65, nash, 400, profex 11,match-box, 7A,DD3, delay,various accoustic guitars, amps, and other necessitys, |
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Lewis John Foote
From: Dorset, UK
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Posted 26 Mar 2008 8:07 am
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howdy, john, if i mentally blanked out the bottom speaker in your diagram, and the wires that fed that speaker i put into a jack plug connection, then made my connection jack to jack on the cab, have i got it,? lew. _________________ pro1,s two round fronts, one square front, sho-bud, S12, LDG,1977, built by paul franklin sen, [THE PROFESSIONAL]nice all original, bandit65, nash, 400, profex 11,match-box, 7A,DD3, delay,various accoustic guitars, amps, and other necessitys, |
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Lewis John Foote
From: Dorset, UK
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Posted 26 Mar 2008 8:19 am
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howdy, john lookin a gain the diagram you sent looks the same as series connection, that makes it 16, ohms, is that right, lew, _________________ pro1,s two round fronts, one square front, sho-bud, S12, LDG,1977, built by paul franklin sen, [THE PROFESSIONAL]nice all original, bandit65, nash, 400, profex 11,match-box, 7A,DD3, delay,various accoustic guitars, amps, and other necessitys, |
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John Roche
From: England
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Posted 26 Mar 2008 8:38 am
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Larry he would end up with 4 ohms, it has to be a series/parallel connection as above without power drop..
Lew, you will have only two wires going out to the external speaker..
If you can take one wire off the speaker marked - in the 400 and connect it to a jack socket , run a wire back from the socket * the other connection on the socket to the speaker. , now connect to the ex cab making sure that the wiring is + - correct..
failing that take to a music shop and ask them to install the socket....JR |
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Lewis John Foote
From: Dorset, UK
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Posted 26 Mar 2008 9:15 am
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howdy, john, ok, thanks, lew. _________________ pro1,s two round fronts, one square front, sho-bud, S12, LDG,1977, built by paul franklin sen, [THE PROFESSIONAL]nice all original, bandit65, nash, 400, profex 11,match-box, 7A,DD3, delay,various accoustic guitars, amps, and other necessitys, |
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Larry Robinson
From: Peachtree City, Georgia, USA
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Posted 26 Mar 2008 9:47 am
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To my understanding, the question was how to wire a Bandit with one 8 ohm speaker connecting to, my understanding, one 8 ohm speaker in an external cab. Is the cab going to be used for Bandit or nashville 400? |
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Lewis John Foote
From: Dorset, UK
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Posted 26 Mar 2008 10:51 am
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howdy, john, done a tempory connection till i get the right materials, sounds ok, workin, fine, when i make the connection theres a very very slight reduction in volume, or tone, i assume cause its drivin two speakers, i made a nice bracket to carry the jack plug, thanks for all your help. lew. _________________ pro1,s two round fronts, one square front, sho-bud, S12, LDG,1977, built by paul franklin sen, [THE PROFESSIONAL]nice all original, bandit65, nash, 400, profex 11,match-box, 7A,DD3, delay,various accoustic guitars, amps, and other necessitys, |
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Richard Sinkler
From: aka: Rusty Strings -- Missoula, Montana
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Posted 26 Mar 2008 10:36 pm
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I could never understand why some amp manufacturers don't put an extension speaker output in their amps. _________________ Carter D10 8p/8k, Dekley S10 3p/4k C6 setup,Regal RD40 Dobro, Recording King Professional Dobro, NV400, NV112,Ibanez Gio guitar, Epiphone SG Special (open D slide guitar) . Playing for 55 years and still counting. |
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Lewis John Foote
From: Dorset, UK
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Posted 27 Mar 2008 1:30 am
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howdy, yes it would benifit a lot of ocasions when the need arises, being theres already the spare bayonet fixings there, yes it is for the bandit, 8,omns, in the amp, and 8ohmns, in the ext, done a temp, a really nice full sound, just some thin else to hump about, lew, _________________ pro1,s two round fronts, one square front, sho-bud, S12, LDG,1977, built by paul franklin sen, [THE PROFESSIONAL]nice all original, bandit65, nash, 400, profex 11,match-box, 7A,DD3, delay,various accoustic guitars, amps, and other necessitys, |
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John Roche
From: England
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Posted 27 Mar 2008 2:05 am
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Lew, how big is the ext cab. I got a cab from a car radio shop wedge shape , just big enough to take a 12"
speaker, I put a Blue Marvel in it , got a great sound out of it . JR |
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Lewis John Foote
From: Dorset, UK
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Posted 27 Mar 2008 2:22 am
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howdy, john, the cab is, 25inchs, tall, 19, wide, 15, deep, its got a 15, inch speaker, a horn, and ported at front, closed back, its got two jacks at the back, i expect to go on again to another speaker, its a proper shop bought item, it says, balanced speaker system, on the back,8ohmns, ive had it 30 years, i used it on my solo singing, one man band days, lew. _________________ pro1,s two round fronts, one square front, sho-bud, S12, LDG,1977, built by paul franklin sen, [THE PROFESSIONAL]nice all original, bandit65, nash, 400, profex 11,match-box, 7A,DD3, delay,various accoustic guitars, amps, and other necessitys, |
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Jim Sliff
From: Lawndale California, USA
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Posted 27 Mar 2008 8:56 am
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Quote: |
To my understanding, the question was how to wire a Bandit with one 8 ohm speaker connecting to, my understanding, one 8 ohm speaker in an external cab. |
No, and as he clarified in the last post the cab has a speaker AND a horn, and the cabinet is rated at 8 ohms. And that's where it can get confusing, as you need to also know how the speakers are wired in the cabinet, and what their individual impedance is. Most amps don't see a multiple-speaker cabinet...they "see" a bunch of speaker wired either serial or parallel and THEN wired parallel to the internal amp speaker.
You need to know what that second jack is if you;re going to use the cabinet....but I'd likely unhook the horn (which usually sound terrible with guitars of any kind) and then wire the 15" directly to one of the output jacks...and remove the other so you don't accidentally plug into an "open" jack, which is not good for the amp.
Your reduction in volume is probably because the phase is reversed on the cabinet - another reason to get rid of the horn and simplify it a bit. If you are running parallel, positives hook to positives; if you're wiring in series John Roche's diagram is correct.
But John's diagram is wrong if what I'm interpreting is correct: If your amp speaker is 8 ohms, your extension speaker is 8 ohms, and the amp wants a 4-ohm load you have to wire in parallel - NOT in series like John's diagram.
But it's still moot until the cabinet wiring is figured out and the horn (hopefully) deactivated - then measure the 15" and see what the impedance is, and it'll be easy to figure out what to do.....if it CAN be done. _________________ No chops, but great tone
1930's/40's Rickenbacher/Rickenbacker 6&8 string lap steels
1921 Weissenborn Style 2; Hilo&Schireson hollownecks
Appalachian, Regal & Dobro squarenecks
1959 Fender 400 9+2 B6;1960's Fender 800 3+3+2; 1948 Fender Dual-8 Professional |
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Donny Hinson
From: Glen Burnie, Md. U.S.A.
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Posted 1 Apr 2008 1:38 pm
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Richard Sinkler wrote: |
I could never understand why some amp manufacturers don't put an extension speaker output in their amps. |
That's because it becomes very easy to burn out the output transistors when you exceed the minimum output load. The logic goes something like this: When people use extra speakers, they're normally using them because they can't be heard. When they can't be heard, that normally means they're pushing the amp. When they're pushing the amp, any reduction in the speaker load increases the power the output transistors must dissipate. All that means that you stand a far better chance of damaging an amp by using an external speaker when the amp isn't really designed for an external speaker.
How do you tell if an amp is designed to use an extension speaker?
Simple, the amp will have an "Ext. Spkr." jack.
If it doesn't, just realize you're pushing your luck. Okay? |
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Larry Robinson
From: Peachtree City, Georgia, USA
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Posted 2 Apr 2008 4:07 am
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In reply to Jim Siff, It was stated that the Bandit speaker AND the ext. speaker CAB were 8 ohms each. Connecting the cab in parallel will give a total load Z of 4 ohms. If the horn tweeter in the cab IS piezo, which was NOT given, then placing the horm in parallel with the speaker in the cab would NOT change the total Z due to the high Z of the Piezo tweeter. But if the horn is NOT Piezo, there would probably be a cross-over network. I believe the reduction in volume is due to the impedence mismatch by adding the additional speaker.
As Donny Hinson stated, if it doesn't have an external speaker jack, leave it alone or realize you're pushing your luck. |
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Mike Poholsky
From: Kansas, USA
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Posted 2 Apr 2008 5:47 am
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Since this thread is about ext. speakers I have a question I'll ask here. I have a '64 Fender Twin Reverb that has an ext.speaker jack. I am using two EVM 12S, 8 ohm speakers. I understand that works out to a 4 ohm load. My question is: Can I use a 4 Ohm 15" ext. speaker plugged into the ext. speaker jack. Or does the ext. speaker need to be an 8 ohm speaker?
How does an ext. speaker plugged into the jack affect the load? OK it's 3 questions.
Thanks guys. |
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John Roche
From: England
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Mike Poholsky
From: Kansas, USA
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Posted 2 Apr 2008 6:42 am
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Thanks John that does explain it. I guess what I don't know is the ext. speaker jack on a '64 Fender Twin Reverb wired in series or parallel? Thanks. |
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Jim Sliff
From: Lawndale California, USA
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Posted 2 Apr 2008 11:01 am
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Extension jacks are almost always in parallel, otherwise you'd have an open circuit and NO sound unless the jack had a switching system to close a connection when not in use. But what's often missed is that adding another speaker puts ALL the speakers in parallel - not one pair's impedance as if it was a single speaker, and then an additional speaker; also, another cabinet with two speakers in parallel means you have four speakers in parallel, and that's not a good thing if they are all 8 ohm speakers and your amp is looking for 4 ohms. It can handle a 2-ohm load OK, but not lower than that. That's when you go to a combination series/parallel wiring to avoid too low an impedance.
Larry - the piezo explanation on the horn makes sense. I hadn't thought of it as any time I've used a cabinet with a horn for guitar I've automatically disconnected the horn, as they usually sound awful with guitar, even with a variable crossover. _________________ No chops, but great tone
1930's/40's Rickenbacher/Rickenbacker 6&8 string lap steels
1921 Weissenborn Style 2; Hilo&Schireson hollownecks
Appalachian, Regal & Dobro squarenecks
1959 Fender 400 9+2 B6;1960's Fender 800 3+3+2; 1948 Fender Dual-8 Professional |
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Mike Poholsky
From: Kansas, USA
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Posted 2 Apr 2008 2:52 pm
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Thanks for the info John and Jim. In the article John posted it states "Note: If more than 2 Speakers are connected in Parallel, so long as they are all the same impedance then the net impedance of the load is equal to the impedance of the one Speaker divided by the total number of Speakers. For Example 3 8 Ohm Speakers in Parallel, the Impedance is 8/3 or 2.667 Ohms." I get that, but what about my example. I have have 2 - 12" 8 Ohm speakers in the amp now and I would add 1 - 15" 4 Ohm speaker into the Ext. Speaker Jack. Does the same formula above apply? |
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