Ampeg B25 2X15 Cab

Jhtjon · #1 05-31-2010, 08:43 AM

I just got a B25 cabinet from a friend who had it in his basement for a while. Unfortunately it does not have any speakers. What would it have come with? and What would you put in it now?

BillyB_from_LZ · #2 05-31-2010, 08:45 AM

Probably CTS speakers. As for now...I'm sure folks will chime in with suggestions.

shoot-r · #3 05-31-2010, 08:55 AM

Quote:

Originally Posted by Jhtjon

I just got a B25 cabinet from a friend who had it in his basement for a while. Unfortunately it does not have any speakers. What would it have come with? and What would you put in it now?

If I remember correctly "fliptops" had speakers for Ampeg cabs.
www.fliptops.com

craig.p · #4 05-31-2010, 09:11 AM

What are you driving it with and how loud do you need to be?

Jhtjon · #5 05-31-2010, 09:35 AM

B25

Loud? what did you say?

shoot-r · #6 05-31-2010, 10:54 AM

Quote:

Originally Posted by shoot-r

If I remember correctly "fliptops" had speakers for Ampeg cabs.
www.fliptops.com

Fliptops has the Delta 15 A 15" speaker. It's 8 ohms, $89.95 ea.
Replaces the original CTS speaker that's no longer available.

JimmyM · #7 05-31-2010, 11:45 AM

www.fliptops.net , btw. and yes, the delta 15a and beta 15 will come the closest to sounding like the old cts speakers they used.

craig.p · #8 05-31-2010, 03:53 PM

I hate to bust up the place but this guy's running only about 50-60 watts into two fifteens and he implied he wants to be loud. So I think efficiency's going to be the watchword. I'd recommend he look for the most-efficient drivers he can find, assuming T-S is correct for the cab. I don't know how to follow through on that for that cab (no specs) so maybe someone else can. To start with, here's what I found out at U.S. Speaker at reasonable price points:

Eminence Beta 15A: 98.2

Eminence Legend CB15-8: 98

Eminence Gamma 15A: 98.6

Eminence DeltaLite II 2515: 99.2

Eminence Delta 15A: 100

Eminence Delta LF15A: 96

Eminence Kappa 15A: 100.5

Eminence Kappa 15LFA: 99

Eminence Kappa Lite 3015: 100.8

Eminence Kappa Like 3015LF: 99.8

Eminence Delta Pro 15A: 101.6

Eminence Kappa Pro 15A: 101

Eminence Kappa Pro 15LFA: 97.8

Eminence Omega Pro 15A: 97.3

Beyma SM-115N: 98

Faital Pro 15PR400 8Ω: 100

Jensen Neo 15-150-8: 100.1

Peavey 1502-8BW: 98.9

P.Audio C15-300MB: 98.6

You'll need to double-check my figures. I'd do it myself except I've gone temporarily cross-eyed after this.

These drivers are 8Ω. If the cab has an impedance selector switch, wire it in, and use the 16Ω position for the B25. If the cab doesn't have an impedance selector switch, wire the drivers in series. The B25 schematic says the amp wants to see 16Ω with just one cab plugged in.

craig.p · #9 05-31-2010, 03:59 PM

Ok, I see that Delta 15A out at fliptops. Would the Pro 15A with 1.6dB better sensitivity be worth the few extra $$$, or am I splitting hairs?

JimmyM · #10 05-31-2010, 10:46 PM

i don't think i ever checked a sensitivity rating in my life. but what i will tell you is that i've ran my b-15 cabs loaded with delta 15a's with an svt and an lmii and they will get plenty loud. i usually run them with a 25w b-15n head, though, and while it's not the loudest thing i ever heard, it's not a quiet rig by any stretch. so i think with 50-60w the op should be fine.

the problem here is that the b25b cab is a smaller cab than most and i believe it's sealed. so the other speakers may or may not work well in that cab. but the delta, while not being the best speaker on the market, is a well-known entity that works in all ampeg cabs and sounds just like the cts's it almost certainly came with.

btw, the b25 runs at 16 ohms, so make sure you series wire your two 8 ohm 15"s, not parallel.

MR PC · #11 05-31-2010, 11:00 PM

Quote:

Originally Posted by JimmyM

btw, the b25 runs at 16 ohms, so make sure you series wire your two 8 ohm 15"s, not parallel.

That would explain why so many of the old b25's turn up not working anymore. I guess Ampeg never thought that users would try other cabs with their product!

craig.p · #12 06-01-2010, 04:36 AM

Not Ampeg's fault in the least. It's the user's job to understand what load the amp needs.

I wonder how many owners ran B25s into cabs with those cabs' impedance selectors set at 4.

Users with one cab unavoidably running at 8 or 4 ohms -- all they'd have to do would be shove an unused/unconnected phone plug into the external speaker jack to enable the transformer's 8 ohm winding, a perfect match for an 8 ohm load and a "not quite as bad" one for a 4 ohm load. A perfect application for those hard-to-solder right-angle Switchcraft phone plugs of old (from a recent thread on the effects board).

denton57 · #13 06-01-2010, 05:37 AM

I have a one of these. It is not sealed, and is a wide and shallow cab. I replaced the original eminence with the factory upgrade Altec 421's.

I never got to try the b25 head with the altec's, but with the eminence I wouldn't describe it as being loud. Maximizing efficiency when selecting speakers would be very important with a 55 watt head. I ended up replacing the b25 witha v4b.

I still have the cab. It sounds good, but is real ackward to move because of it's demensions and dolly caster locations. I replaced it with a LDS 1x15 with a 3015.

If I were loading speakers in this cab, I'd go with the 3015's. Awesome speaker with 100
sensetivity.