1960 A Cab wiring question...

[Peaj]

I'm pretty inexperienced with any maintenance on my gear, but lately have been doing some speaker changes in my 1960A cab. The one with this back plate, 8ohm stereo/4ohm mono left side, 16ohm mono/8 ohm stereo right side. I believe this is series parallel wiring. I swapped it from the X pattern T75 V30 combo it came with to all V30s a few weeks ago, and today swapped it to T75s on top and V30s on the bottom. Unfortunately I mind ****ed myself while doing it and got the wires confused, so I resorted to Google to figure out the correct wiring. With the speakers, I went bottom left positive to top left positive, bottom left negative to top left negative. Bottom right positive to top right positive, bottom right negative to top right negative. Here's the part where I mind ****ed myself, with plugging them back into the jack.

Plugging them back into the jack, I went top left positive, top left negative, top right positive top right negative, so it's + - + - . For some reason I convinced myself it had been + - - + when I first opened it up.

Any advice?

[dave74]

You can use a multi-meter to see what you have going. Just search "testing speakers with multi-meter". That's all I have.

[PFDarkside]

Post some pictures of your wiring.

the important thing is impedance for safety, the phase can be figured out. Use a cable plugged into each Jack and use a multimeter to verify you have it correct in terms of series/parallel. (Does the 4 ohm read ~3 ohms, do the 8 ohm jacks read ~6 ohms, does the 16 ohm Jack read ~13 ohms.)

After that you can use the 9V trick to make sure that all of them are moving the same direction and to make sure the correct “pairs” are wired how you want.

[Peaj]

Red is +, Black is -.

[dave74]

I'll be curious of which way you like them best. For me the X-pattern is better for slant cabs, but with straight cabs I don't think it matters as much.

[Peaj]

I'll be curious of which way you like them best. For me the X-pattern is better for slant cabs, but with straight cabs I don't think it matters as much.

Definitely prefer the Top/Bottom setup as opposed to the X pattern. X Pattern with the different sensitivity speakers just sounds really uneven/unfocused to me, and I didn't like how the sound changes depending on where I was standing. Top/bottom is a single uniform sound.

It sounds like a T75 cabinet with a bit of a V30 accent, the 75s definitely are advantaged by being on top and being in the angled slots.

[dave74]

Definitely prefer the Top/Bottom setup as opposed to the X pattern. X Pattern with the different sensitivity speakers just sounds really uneven/unfocused to me, and I didn't like how the sound changes depending on where I was standing. Top/bottom is a single uniform sound.

It sounds like a T75 cabinet with a bit of a V30 accent, the 75s definitely are advantaged by being on top and being in the angled slots.

I kind-of hear it both ways, but that's definitely true with the speakers being so different on volume, and especially perceived volume. (as with the t75/v30 mix)

When standing anywhere close to the cab I agree with what you're saying, but if you're in a large area and can get at least 15 or 20' away from the cab then I like X much better in slants. In straight cabs I could go either way but usually prefer top/bottom.

The difference when moving side to side with the X-pattern is only something I notice within that small range directly in front of the cab. Once I'm even slightly off axis of the cab I couldn't tell you which side of the cab I'm on based off the difference in speakers.