Ampeg B-15N: best replacement speaker today

Discussion in 'Amps and Cabs [BG]' started by boroman, Nov 18, 2017.

  1. boroman


    Apr 27, 2009
    I've probably read every B15 "replacement speaker topic" over the web in the last weeks. My '69 B15N CTS speaker is blown.

    - I have asked Weber - they recommend "Bass15F" (175w, ceramic)
    - I have asked Fliptops - they recommend Eminence Beta15a
    - Some people here swear for Delta 15a as even better choice than Beta
    - WGS recommends their BG15C (300w ceramic) - but it's more close to JBL

    But the first question is - almost every B15N that's listed over the web has a replacement speaker or reconed CTS. Why? Is that a design flaw? I mean, they put in CTS speakers that had lower power handling than B15N's power amp? So, if that's true, better to recone an old one (and risk blowing it again in near future) or put there better replacement?

    I have also never played B15N with factory installed JBL D130/D140 and a lot of people talk about it that this was the best speaker for B15N... so?...
  2. DaveDeVille

    DaveDeVille ... you talkin' to me ?? Supporting Member

    ...good questions ,
    which 15" speaker does Ampeg recommend as a replacement for the B15 cab ?
    Last edited: Nov 18, 2017
  3. Lots of people dig the beta, the Delta works too - less low end, but overall more sensitive. That being said, at this wattage it's kinda hard to find something that at least won't work. I know JimmyM likes his with a beta if I recall. It's been a long year though, so I could be wrong.
  4. BassmanPaul

    BassmanPaul Inactive

    Not a design flaw by any means. Drivers age and eventually fail. All B15s are old amplifiers.
  5. Soulfinger


    Sep 20, 2004
    Upstate NY
    Just been through this dilemma myself (see link below)---the B25B is about the same size (per driver) as the B15. Now I have Betas in both and couldn't be happier.

    My Altec 421s sound lousy (V4B/B25B)
    DaveDeVille likes this.
  6. beans-on-toast


    Aug 7, 2008
    Eminence Delta 15A works well in 60’s B-15N cabinets.

    Correction: I initally had Alpha, meant Delta
    Last edited: Nov 19, 2017
  7. Bassmec


    May 9, 2008
    Ipswich UK
    Proprietor Springvale Studios
    Well it appears that you disagree with Cenzo Townsend as well, who owns a very smart original Altec option B15
    he specifically chose for his world class studio Decoy, although of course the driver in his, is the original Stepped Alnico magnet Altec 418 Series II.
    I have a pair of very old SVT 115 cabs with the same drivers in which in A/B testing against loads of other manufacturers 15" cabs record extremely well, brighter and more forward in the upper mid that the stock CTS 15"
    I prefer the 418 but have used 421a's in the past and have not had a problem with no high frequency response as you describe.
    It's also interesting to note that you also appear to disagree with Ampeg Heratige as they paid eminence to try to clone the Alloy voice coil cap, with the bright tone ascociated with the original no longer available Altec options.
    There must be something badly wrong with your old Altec's as they just don't sound as you describe them normally.:)X
    PS Perhaps someone dropped some Hi Fi woofer re-cones in them and put Alloy voice coil caps on to look right.

    Attached Files:

    AlexanderB, jkalads, Ric Vice and 2 others like this.
  8. bobyoung53

    bobyoung53 Supporting Member

    I have a 1978 B-15S with the original speaker in it, not sure if it's a CTS speaker or not but it looks like one..
  9. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
    My B-15 cabs have Deltas in them, actually. They're great in those little double and single baffle B-15 cabs, but was not a fan of them in the 77 B-15N I used to have. Mine had a 71 CTS in it...don't know if it was a recone or not, but it was a good bit darker in the highs than the Delta, and in that big Thiele cab the Delta is really scooped.

    The JBL D130/140 was a popular speaker for the smaller B-15 cabs, but the upgrade speaker for your B-15 was the Altec 421a (actually in 69 it was the 418b, but the 421a is more highly regarded). It worked well in those bigger cabs because it had more mids and good highs. The CTS also works well, but it's mostly about low mids and mid bass.

    I really don't know what modern speaker I'd get, but the Faital 15PR400 is one I've always wanted to try in one of those Thiele cabs. Not cheap, though.

    It would have been Eminence in 78. If there's a number on the magnet that starts with a 67, it's Eminence. If it starts with 137, it's CTS.
  10. boroman


    Apr 27, 2009
    As I see form specs, Alpha > Beta > Delta in terms of sensitivity (97, 98.2, 100dB) and frequency response - Delta curve looks also most natural. But how this looks in real (and most important in B15N) I don't know. Alpha should be cool too with less power rating and better ability to drive the speaker.
  11. beans-on-toast


    Aug 7, 2008
    I corrected my post above, I should have said Delta 15A.
  12. Ampslut


    May 15, 2017
    Barrackville WV
    Not to derail this as I don't have a clue as to what would be the proper replacement but, what about the Eminence
    LEGEND CB158. I bring this up as this is one of 3 recommended 15" bass replacement drivers the Eminence recommends. Bass Guitar | Eminence Speaker
  13. Whelp, I've been wrong before :)
    Last edited: Nov 19, 2017
    JimmyM likes this.
  14. scuzzy


    Feb 15, 2006
    Troy, MO
    fliptop site says the beta is their choice of replacement. i have one sitting in my amazon cart right now, considering it. but the peavey scorpion in my cab actually sounds really nice, to my surprise. we'll see how much $$$ santa brings.....
  15. boroman


    Apr 27, 2009
    I have 3 old ampeg cabs with original speakers and I push them hard for xxx years. Not a single problem... How many watts those CTS handled? And is there any difference between square magnet 15" CTS and round-magnet from the same era?
    Bill N and 40Hz like this.
  16. 40Hz

    40Hz Supporting Member

    May 24, 2006
    I’ve got a B-15N I’ve owned since ‘69. It’s been played regularly and occasionally pushed.

    It still has the original square magnet CTS speaker it came with and it sounds fine.
    Keyser Soze, boroman and jnewmark like this.
  17. bobyoung53

    bobyoung53 Supporting Member

    Mine has a square magnet that starts with 67, I wonder if they had left over CTS speakers in 78? The second pair of numbers is 78.
  18. boroman


    Apr 27, 2009
    67 means Eminence, 137 is CTS, and yes, Eminence took over CTS in Ampeg mid to late 70s. Don't know when exactly speaking of B15's; but in SVT cabs it was around 1974-1975
    bobyoung53 likes this.
  19. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
    Doubt it. Once CTS got out of making speakers, they stayed out.
    bobyoung53 likes this.
  20. bobyoung53

    bobyoung53 Supporting Member

    When did they stop?