Dating Speaker from B-15S

I think the only difference between the CTS and the Eminence is the brand name; it is as though Eminence absorbed CTS and continued to make the speaker. Someone please correct me if you know otherwise.

These are well-regarded speakers for the B-15. I have tried four different speakers in my B-15N (JBL D140, Altec 421, Jensen C15L, and a Weber Neo). Even though Ampeg offered the JBL and the Altec as upgrades, none of my replacement attempts sounded as good as the original square-magnet driver, so I reinstalled it.

Of course, "good" is highly subjective. For me, "good" was equivalent to "how a B-15 is supposed to sound." Not particularly high fidelity, yet punchy and creamy. I think it has something to do with the unridged and very stiff cone.

They will not handle much power and may not work so well for other amps.

 

Yeah with that amp, let it do what it does at moderate/low volumes and mic that puppy. The speaker is part of its charm.

 

in mine I tried a JBL 2205 and an Altec something or other. Both were very nice but the original square magnet driver was a tad better in my view.

 

I'd guess that had more to do with the Emi being a better match for that particularcab.

The D-140F is my favorite sounding bass speaker. Kind of weak by today's standards, but it has the best sound (for me). I give the Altec 418B second place, and it doubles as a mighty fine 15" for guitar.

 

From the perspective of power handling, the swap would make sense, since the S makes more power. But you "quite like" the Delta 15, so as long as you're careful with volume, you should be okay as is.

 

Dating a speaker?

I've dated worse....

 

I’ve got the square magnet CTS in my B-15N.

I’ve heard other speakers in B-15 amps. I found I always preferred the tone of the CTS.

 

Then go unload the CTS and use whatever you want. Your CTS will net a quick sale on the used market. There are more than enough B-15 owners who will be happy to take it off your hands.

 

Apologies! Guess I missed that.

The CTS in the B-15N is a marriage made in heaven to my ears. Really like mine.

Can’t comment in the proposed B-15S/Delta combination. Never played one of those. So I’ll defer to those who have and are therefore qualified to respond to that part of the question.

 

CTS wasn't absorbed. They just changed their focus and got out of making speakers. They're still around and thriving very well, making lots of electronic parts, including many of the potentiometers we use in our guitars and amps.

Fun fact...Bob Gault, the founder of Eminence, used to work for CTS and started Eminence in 1966 with a 3-speaker a day commitment from Ampeg for their B-18's.

 

Oh, regarding the difference between CTS Ampeg speakers of the 60's and 70's, as well as the Delta 15a...

The 60's Ampeg CTS's are a little brighter than 70's CTS's. I don't know how that B-15S Eminence sounds compared to them, but I used to have a 77 B-15N with a 71 CTS in it, and I couldn't use them interchangeably. Tried it once, and the 71 CTS was too dark in the 60's cab and the 66 Ampeg labeled CTS I got for my 64 B-15N cab was too midscoopy for my tastes in the 77 cab, and it's all because of the cab differences, because nobody would ever accuse my 64 cab of sound midscoopy.

And the Delta 15a is a dead ringer tonally for the 66's CTS, so I would probably avoid putting either in a B-15S cab.

 

Ampeg, more than any other company that I know of, was great at matching the speakers to the amp. Leave any B15 as stock as possible, and if you need more clean volume, buy an SVT.

 

I recently acquired a '79 B-15s from a friend with a EVM 15b series II. The speaker sounds pretty darn good paired up and I don't plan on changing it for now.

I'm curious to try out the Altec variant first comparison.

 

Eminence speaker 29th week of 1978. Good speaker.

Ampeg was an early customer of Eminence. Building 18” speakers for Ampeg helped get Eminence started.

From the TalkBass Portaflex Wiki. An Altec speaker was a more expensive option.

https://www.talkbass.com/attachments/b15s-brochure-pdf.981203/