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Rig decisions: restoring a B25B cab?

Discussion in 'Amps and Cabs [BG]' started by paparoof, Jan 5, 2012.


  1. paparoof

    paparoof Supporting Member

    Apr 27, 2011
    Minneapolis
    fEARful koolaid drinker
    I have an old Ampeg B25B cab (I'm guessing from the late 60's - it has the ohms switch on the back). Got it 20 years ago for $100. It's got some big-ass JBL that weighs about 700 pounds and some no-name crappy 15 - both of them are torn but they make bass guitar-like sounds. The tolex was so tattered I just peeled it all off and ran it naked. The corners, handle straps and dolly are long gone.

    So now I'm 20 years older and auditioning for cheesy cover bands. I'm deciding if I should "restore" this cabinet or turn this one into a coffee table and just get something new. I can still get this thing out of the basement and into my car by myself, but I'm old enough and complain about my back enough that I really like the idea of something smaller and lightweight like a pair of 112's.

    I'm assuming the cheesy cover band I end up with will be playing places with vocal-only PA's, so I'll need my rig to fill whatever bowling alley or VFW we're playing in all by itself.

    I'm currently running a Sansamp RPM into the effects return of an Ampeg B500DR head (solid state). Power is 300w@4 ohms, 500w@2ohms. So not a lot of power, I'll most likely sell the Ampeg head and upgrade to a bigger dedicated power amp at some point soon so the drivers that go into this cab are going to need to handle considerably more than what I've got now.

    So here's issue #1:
    I've read every B25-based thread I can find in here for driver replacement suggestions, so I'm fully aware of the Eminence Beta 15a and Delta 15a, but they're kind of old threads are these still the drivers of choice or is there anything newer or better suited? If it's still just these two, which one should I go with?

    Issue #2:
    The box has no stuffing or lining in it - tell me what to do there. Be specific.

    Issue #3:
    Then of course if I install new drivers, that will spur me to replace the grill cloth, paint it with Duratex and get new corners and handles to return it to its "proper" state. After all this money and effort, is it worth it? Am I just going to have a nice looking but farty cabinet that can't even keep up with a cheap Acoustic 410? If I set a budget of $500, should I give up on this box and get something else?

    Okay! I'll be working out Mustang Sally and White Wedding while I await your wisdom.
     
  2. JimmyM

    JimmyM

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    1. Still the go-to drivers for that cab and most old Ampegs.

    2. Stuffing if sealed, lining if ported is the rule. The bedliner foam that WalMart sells is often recommended by one of the cab experts on here.

    3. You likely won't get your money out of it if you spend more than $200, but I think it's worth fixing up. I'd fix it up if I had it. I've not heard that particular cab, but old Ampeg cabs sound awesome and those on here who have one really love it. With a couple Betas or Deltas in it, it'll blow away an Acoustic 410 tonally and be at least as loud, if not a little louder.
     
  3. paparoof

    paparoof Supporting Member

    Apr 27, 2011
    Minneapolis
    fEARful koolaid drinker
    Wow thanks for the fast response Jimmy. Was hoping I'd hear from you.

    Can you help me decide between the Beta or the Delta?

    It's not sealed or ported - there's just an open spot in the baffle. In one of the threads I read about this, someone called it "leaked".

    Here's 3000 words to better describe it:

    [​IMG]

    [​IMG]

    [​IMG]
     
  4. gbazinet

    gbazinet

    Aug 11, 2010
    Maine
    +1 on what Jimmy said. You won't get much out of it in resale unless you restore it with vintage/stock parts. But if you fix it up for yourself to use with modern replacements it could be a great cab.
     
  5. paparoof

    paparoof Supporting Member

    Apr 27, 2011
    Minneapolis
    fEARful koolaid drinker
    Yeah I don't really care about resale value. I'm keeping it either way - it's a sentimental thing.
     
  6. JimmyM

    JimmyM

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    BTW, don't forget that if it's wired in series that it's 16 ohms. You will want to rewire it for parallel to get 4 ohms if you get Betas or Deltas.

    So the Betas and Deltas...I have only used the Deltas and I love them in my B-15 cabs. The Betas aren't exactly alike, but their frequency plots look close enough to not be drastically different sounding. And the Betas have more cone travel (xmax) so you'll be able to go a little louder with the Deltas, and they're about $30 less than Deltas. The Deltas, however, will take a pretty serious pounding, too. I think if I had to do it over again, I'd go with Betas just because they're cheaper, but the Deltas have not disappointed me in the least.
     
  7. I think the Delta Pro's are considered Eminence's version of EVM 15L replacements. Might not get as much low end but I'm sure they will sound great in there, as well as the other Eminence 15's.

    I say keep the cab. I'd take it over a 4x10 any day. Just a little insulation, some new corners, speakers and call it a day. That grill cloth looks better than a lot of others I've seen of that era.
     
  8. paparoof

    paparoof Supporting Member

    Apr 27, 2011
    Minneapolis
    fEARful koolaid drinker
    Thanks Jimmy - I'm good to go on the wiring.

    But I don't understand why more cone travel on the Betas means I can go louder with the Deltas - I would think that would be the other way around?

    If I ever run out of beer I could just suck on a corner of that grill cloth.
     
  9. dave zilla

    dave zilla

    May 17, 2011
    There's no holes in the cloth in the picture. Could you just get a carpet cleaner type product?
     
  10. JimmyM

    JimmyM

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    The extra xmax in the Beta means you'll be able to put more wattage into it before it starts farting out. Honestly, though, I don't know if it would make much difference in a smaller cab like the B-25B cab. You can smack Deltas pretty hard, too. We might need a ruling on that from one of the speaker gurus on here. But either way you go will be fine. Just slightly different shades of vintage kickass tone.
     
  11. BillyIVbass

    BillyIVbass

    Sep 24, 2008
    PA
    Gear Reviews Guitar World Online
    I rock a single Eminence Kappa Pro 15" every weekend. It's in an old Peavey cab and I let it sit in a trailer all week through hot and cold weather. I am by no means an expert so I don't know if that will work in your Ampeg.

    Cosmetically, I'd just clean up what you have and rock it. With old Fender grills I have had good luck with a few quick rounds with a carpet cleaner.
     
  12. coreyfyfe

    coreyfyfe Supporting Member

    Nov 19, 2007
    boston, ma
    I have the same cab, went with Deltas for mine but I also have a Beta in my B-15 cab. They're pretty similar speakers. I think the Deltas have a bit more of an even sound across the spectrum where the Betas have a more robust mid-range, but not having compared them in the same cab I can't say for sure if that would hold. You're lucky you got a front loaded version of this cab, or at least someone already set it up that way for you. Mine is rear loaded and taking off that back panel is a pain in the backside.

    If you're leaving the switch active then it doesn't matter, but if you decide to remove the switch from the circuit, just remember to wire the speakers in parallel for 4 ohms when you set them up. I took the switch circuit out on mine (just unhooked the wires) since I planned on using it with my SVT and didn't want it getting bumped to 16 ohms accidentally.

    This is definitely a vented cab with the small porting there so the two bits of lining that are already in there should be sufficient, no need to stuff the cab.
     
  13. paparoof

    paparoof Supporting Member

    Apr 27, 2011
    Minneapolis
    fEARful koolaid drinker
    Yeah I was a little confused when i saw people talking about pulling the back off. This one doesn't come off.

    I'm going to leave the switch bypassed and permanently wire it for 4 ohms (actually that's already how I have it setup and I'm just going to keep it that way).

    There's no lining or stuffing at all in the box. Previous owner must have pulled it out.

    Should I get some mattress topper that I can blow through and just staple it to all the interior walls? Is it really that simple?

    How thick should the lining be?
     
  14. paparoof

    paparoof Supporting Member

    Apr 27, 2011
    Minneapolis
    fEARful koolaid drinker
    This makes me happy. :D Thanks Jimmy.

    Best place to order the drivers from?
     
  15. will33

    will33

    May 22, 2006
    austin,tx
    Lower power amps----Delta's

    Higher power amps----Beta's

    Your amp and especially any future bigger amp----Beta's-they'll handle more power in the lows. Pretty inexpensive too. You can get that thing sounding and looking nice for a lot less than $500.



    Don't forget the "D" in Mustang Sally.:D
     
  16. JimmyM

    JimmyM

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    I'd go to Amazon and see what you can do. Been seeing some good deals on Amazon lately.
     
  17. coreyfyfe

    coreyfyfe Supporting Member

    Nov 19, 2007
    boston, ma
    Amazon, Music123, and US speaker usually have pretty decent prices. If you use google shopping you will get a fair number of sellers, but look around as some of them are with free shipping and others are low prices with $15-25 shipping that puts it in a higher range.

    As far as the padding, mine just has two squares of yellow fiberglass insulation looking stuff behind the speakers - one behind each. I thought I had a picture of the inside of the back panel but I can't really find one.

    This is the rear access with the deltas loaded in:

    [​IMG]

    This is my B-15, but the padding on the back of the cab looks just like this:

    [​IMG]

    I think I have a picture of the actual back panel on my computer at home, if I can find it I'll upload it later tonight so you can see exactly how it looks.
     
  18. paparoof

    paparoof Supporting Member

    Apr 27, 2011
    Minneapolis
    fEARful koolaid drinker
    Sweet - pics really help clear it up. Thanks!
     
  19. paparoof

    paparoof Supporting Member

    Apr 27, 2011
    Minneapolis
    fEARful koolaid drinker
    Okay so I have my batting, and a pair of brand new Beta 15a's here in front of me (and an audition this coming Wednesday).

    I pulled the drivers outta the box and the JBL is an e145 (8 ohm). It's VERY heavy. The cone is actually in okay shape but the surround has a few tears in it.

    Not finding a lot on the Google machine about this driver. Is this driver worth re-coning or hanging on to? What should I do with it?
     
  20. BogeyBass

    BogeyBass

    Sep 14, 2010
    ummm yah a JBL E-145 will outperform the betas 10 fold

    The JBL would even outperform a legend cb158, and its twice as much cost wise as the betas.

    A reconed E-145 can sell for 180 to 250 dollars.
     

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