I'm new to the forum, so please forgive me if this topic has been hashed to death, I know opinions about speakers vary all over the place. I've got a neat old Airline "Twin Twelve" 62-9015A amp, has the original 12" Fisher speakers.They are sounding a bit tired, and the amp tends to have a "dark" sound anyway, so am looking to put another pair of 4 ohm speakers in it. Don't need to spend tons, I've always liked the Eminence Legend 1258's for the money, but they don't make a 4 ohm version.
What might you all recommend to brighten it up a bit, without breaking the bank>
Yes, wired in series! So you're right, I could parallel two 16 ohm speakers. This also has the OT wired separately to the speakers, I'm not familiar with the way this was done, it's wired like the photo in the link below. If I wired two speakers in parallel, how would I wire the OT?
According to a schematic I found in Jack Darr's book, there is a choke across the OT secondary (in parallel with it). The speakers are in series, so you don’t need to do anything different with the OT and the choke, just connect everything in parallel, OT, choke, and 2x 16Ω speakers.
martin manning wrote: ↑Thu Mar 21, 2019 7:02 pm
According to a schematic I found in Jack Darr's book, there is a choke across the OT secondary (in parallel with it). The speakers are in series, so you don’t need to do anything different with the OT and the choke, just connect everything in parallel, OT, choke, and 2x 16Ω speakers.
Thanks, Martin! Pardon my stupidity, but do you mean to connect the speakers in parallel (which I do understand ), and still have one lead of the OT go to one speaker, and one to the other? Or have both leads go to each of the 16 ohm speakers, so it is also basically "parallel?
Thanks for being patient with my newness to this!!
This is how I see it as it is and how you would wire it for 2x 16Ω. The red polarity dots I marked are arbitrary, but of course you'll want to wire the speakers in phase, and preserve the phase relationship with the amp.
Thank you so much, Martin! I know some folks get irritated when "newbies" such as myself ask these simple questions, I appreciate your patience, and time to explain it to me!
martin manning wrote: ↑Sat Mar 23, 2019 3:34 pm
Sure, no problem. This is an odd arrangement with the choke across the output.
That it surely is. I can only guess the designer was trying to filter low frequency signals. But why why why do it that way? To make sure electric guitar sounds thin and tinny - "like it's supposed to" according to some people back in the dark ages? Maybe save stress on those cheapo buck and a quarter speakers? On rare occasions I run across an old Premier, Dano, Sears, Wards, etc amp that has this arrangement I do away with that choke. So far no wrecked amps nor speakers. Also no customer complaints.
Thanks for your input! Maybe you & Martin can explain to me what the "choke" actually is, and what it's doing. When you said that you've removed it in amps that have it, do you mean you just remove the wires from that small OT to the speakers? Or is that OT part of the "choke"? I had our local tech replace a bunch of caps in the amp, he was the one who suggested that a better pair of speakers would make it sound a lot better, but he never mentioned anything about that wiring arrangement. I'd just as soon simplify anything I can with the amp!
I'm planning on replacing the speakers with some decent Eminence or Celestion's, sounds like I can just remove the choke and everything should be fine, correct?
A choke is not a transformer, it's an inductor. It's the opposite of a capacitor in that it passes low frequencies easier than high frequencies, so it's cutting lows at the last possible point in the signal chain. It will look like a small transformer, but it will have only two leads. You can just disconnect it.
martin manning wrote: ↑Tue Mar 26, 2019 12:59 pm
A choke is not a transformer, it's an inductor. It's the opposite of a capacitor in that it passes low frequencies easier than high frequencies, so it's cutting lows at the last possible point in the signal chain. It will look like a small transformer, but it will have only two leads. You can just disconnect it.
Thanks, Martin! I started reading about chokes right after I posted that, and sounds like there's no need for it with decent speakers. Very unusual.....thanks again for all the help!
I've got a neat old Airline "Twin Twelve" 62-9015A amp, has the original 12" Fisher speakers.They are sounding a bit tired, and the amp tends to have a "dark" sound anyway, so am looking to put another pair of 4 ohm speakers in it. Don't need to spend tons, I've always liked the Eminence Legend 1258's for the money, but they don't make a 4 ohm version. 
), and still have one lead of the OT go to one speaker, and one to the other? Or have both leads go to each of the 16 ohm speakers, so it is also basically "parallel? 