Jensen C15N vs Eminence Beta 15a

C15N or Beta 15a in a double baffle cabinet

  • Jensen C15N

    Votes: 3 25.0%
  • Eminence Beta 15a

    Votes: 8 66.7%
  • Something else

    Votes: 0 0.0%
  • I still don't understand this whole carrots thing

    Votes: 1 8.3%

  • Total voters
    12
Howdy, folks!

I'm seriously considering one of the Portaflex-style cabinets from Vintage-Blue (or maybe Fliptops) with the double baffle design, but I'm kind of at odds as to which speaker to get. The spec sheets, at least as far as the bits I can understand, like sensitivity and wattage handling, indicate the Beta 15a might be a bit "better", but that's awfully subjective when it comes to what we like to hear. It's also probably a few bucks less expensive, but the price difference isn't a factor.

Short term plans are for a cabinet with an 8 ohm speaker. It will initially be paired with an early 70s Bassman, because I have one. Long term is to eventually pick up a PF-50t and then possibly a second matching cabinet, in that order.

I'm very interested in hearing opinions about each of those speakers from people who have used them. It would be super nice if you've played through one mounted in a B15 or reproduction cabinet. Double-plus-good if you've played through both speakers in said cabinets. :)

Just to clarify, I'm looking at new production speakers. I'm not going down the vintage/collector's item rabbit hole.

Thanks so much! TB seems to be a wonderful resource for this kind of thing, since it's darn near impossible to try this stuff out without buying it first.

Links to spec sheets, if'n you're interested:
Eminence Beta 15a
Jensen C15N
 
I've had three B15Ns over the years, two double baffles and a single baffle, and between the two double baffles the early larger port and later small port style. I've had the stock CTS, JBL D140F and K140, Altec 421A, eminence beta, and I think I tried an eminence delta as well? I had an old Jensen concert 15 in another 60s ampeg cab and have a weber bass 15 in my 50s ampeg bassamp. I haven't tried the reissue C15N you've linked here but have used some of their guitar 12" speakers and found them just okay. Between the C15N and the beta 15 I'd take the beta all day. I think my favorite so far in the double baffle cabs has been the D140F.
 
I've had three B15Ns over the years, two double baffles and a single baffle, and between the two double baffles the early larger port and later small port style. I've had the stock CTS, JBL D140F and K140, Altec 421A, eminence beta, and I think I tried an eminence delta as well? I had an old Jensen concert 15 in another 60s ampeg cab and have a weber bass 15 in my 50s ampeg bassamp. I haven't tried the reissue C15N you've linked here but have used some of their guitar 12" speakers and found them just okay. Between the C15N and the beta 15 I'd take the beta all day. I think my favorite so far in the double baffle cabs has been the D140F.

I have a D-140 in my B-15S, sounds really good, deep and clear.
 
  • Like
Reactions: AstroSonic
Jenson speaker has a (Fs) or Resonant frequency of 74 Hz
And can travel 1mm before reaching 10% distortion. ( Xmax)

It is a perfect example of the worst speaker you could use for bass.

The Delta15a and Beta15a are very common speakers for the classic PF cabinets.

And both have a more proper Fs around 35 to 40 hz
and can travel between 2.7mm to 4mm before 10% distortion.

Technically the Delta has a larger magnet and voice coil and can handle more heat thermally. 2.5" compared to Beta 2"
So it has a higher wattage rating.
Usually most go for the Beta because even though its thermal rating is lower.
Mechanically it has slightly more travel before distortion at 4mm.

You can also lower the tuning of the cabinet by plugging a few of the port holes.
Ideal tuning for the Beta would be around its Fs of 35 Hz. Typical reflex/ported cab would be tuned
3 to 5 hz above Fs
 
Last edited:
Jenson speaker has a (Fs) or Resonant frequency of 74 Hz
And can travel 1mm before reaching 10% distortion. ( Xmax)

It is a perfect example of the worst speaker you could use for bass.

The Delta15a and Beta15a are very common speakers for the classic PF cabinets.

And both have a more proper Fs around 35 to 40 hz
and can travel between 2.7mm to 4mm before 10% distortion.

Technically the Delta has a larger magnet and voice coil and can handle more heat thermally. 2.5" compared to Beta 2"
So it has a higher wattage rating.
Usually most go for the Beta because even though its thermal rating is lower.
Mechanically it has slightly more travel before distortion at 4mm.

You can also lower the tuning of the cabinet by plugging a few of the port holes.
Ideal tuning for the Beta would be around its Fs of 35 Hz. Typical reflex/ported cab would be tuned
3 to 5 hz above Fs
Beta also costs less.

Both are killer in those cabs, but the Delta's a little brighter and doesn't go quite as low as the Beta. The tone ends up being almost a dead nuts match to a 66 CTS Ampeg labeled speaker that I have in my original double baffle cab. Only thing is with those cabs is you have to be careful when you flip them and maybe put a piece of felt on the magnets where the transformers can bang into them. But for me it's down to whether you want the lows a little extended or the highs a little extended. Beta for lows, Delta for highs.