Ampeg B-15s - new speaker for different tone?

[auftakt]

Hello!

New guy here. I've been reading your forums quite a bit to try and learn a little more about bass amps. I am a guitarist originally but recently started playing bass as well. Last week I picked up an absolute mint condition 1979 Ampeg B-15s. Not a bad first bass amp!

While I'm loving the tone for more old-school kind of sounds, I'm not entirely convinced that the sound is appropriate for the current project I'm playing in. Believe it or not, I find the sound a little too thick and boomy.

I realize that this is largely a factor of cabinet and room. However, I am wondering if any of you have replaced the speaker in the cabinet to give a slightly more balanced sound? It currently has a square magnet Eminence driver. Are the newer Eminence offerings (thinking Beta/Delta) a little more flat in their response?

I'd love to hear anyone's experiences with changing speakers in their 70s B-15!

Thanks!

[spacebassed]

For vintage I'd throw an Altec or EV in there, for current manufacture its hard to beat a Beta or Delta in these - yours is in superb condition!

EDIT: If you're looking to get more midrange cut the Altec would be my choice, the Beta/Delta sounds pretty similar to the square mag CTS that were often used in the old portaflexes.

[auftakt]

I'd definitely be going for current manufacture. I'd like something that counteracts the 100-175Hz boost I am perceiving from the cabinet -- it's currently a bit too boomy for my tastes.

[gbarchus]

Don't forget JBL.

[P-oddz]

Man, that thing is CLEAN!!!
Congrats!

[auftakt]

Thanks for the kind words, folks. I too was surprised at the condition of this one!

gbarchus: have you compared the JBL vs Eminence old and new by any chance? Any comments as to their boominess?

[fazeka]

Holy crap! CLEAN MEAN MACHINE! Congrats!

[Giorgetto]

Wow that's one of the cleanest B15S's I've seen. I bought one brand new in 1970 and played it for about ten years and just loved the tone. Mine came with the upgrade Altec 421A and I've always wondered what that would have sounded like with a modern speaker like an Eminence 3015. I don't know if that speaker would work with regard to box displacement etc. but I do know that it would make the cab a lot lighter.
My B15S with the Altec weighed over a hundred pounds,that Altec was one very heavy speaker.

[auftakt]

Giorgetto, did you find the tone with the Altec to be very boomy/muddy? I know these amps are supposed to have that bloomy, full bottom-end (as opposed to a more modern sound) but I'd like to try and get it somewhere in the middle. I play half-flats on that Squire CV p-bass.

spacebassed, just saw your edit. Good to know. I should try and hunt down an Altec. Too bad they are so hard to find!

[MN_Bass]

Do you have a time machine?, you must have traveled back and bought that , very nice and clean. roll some bass off on the amp and that might help with the boomy sound. Try some labella nickle rounds on your p, they really punch through a b15.

[auftakt]

I definitely need to spend more time with the on-board EQ -- good call MN Bass. I find it to be a bit finnicky between too much low-end and not enough. Definitely need to spend more time with the amp! Thanks for the string advice too. I'll keep an eye out for those when it's time for the next set.

[Wesley R]

I used a B15S as my main amp from about October 1974 through 2005. Many of those years it saw gig uses 3-5 nights per week. It came with a CTS15G54B. Later I used a Gohleon (really super-efficient and string bass sounding when used with an Ampeg Baby bass), a JBL K-140, which was barky, and not smooth sounding in that cabinet, a Pyle of some sort, and as ext. cabinets a few times an old 360 cab, and an oddball 1-18”. Yes it ran out of power with the extension cabs, but did make it through the typical VFW, Wedding, Strip Club gig.
I was told the cab for the B15S was basically ½ of a BT140 cab. I do know for reasonable fact that the too obtain the same SPL with JBL, I needed to turn the Volume up a tad on the amp as compared to the Gohleon.

[Giorgetto]

Originally Posted by auftakt

Giorgetto, did you find the tone with the Altec to be very boomy/muddy? I know these amps are supposed to have that bloomy, full bottom-end (as opposed to a more modern sound) but I'd like to try and get it somewhere in the middle. I play half-flats on that Squire CV p-bass.

spacebassed, just saw your edit. Good to know. I should try and hunt down an Altec. Too bad they are so hard to find!

Auftakt,

My B-15S had a very pronounced bottom but I wouldn't call it muddy really and a bit of bloom is to be expected in a tube amp with a single 15 especially with an Altec 421A. IMHO The tone was perfect for the studio and small venues. I wish I still had it but it was too heavy for me to load in/out. BTW I played an Ampeg AMB-1 scrollhead with La Bella flatwounds at the time.

[Bass 45]

Based on the condition - you can get plenty of money for it, and then buy any number of modern sounding amps. If you wanted to stick with a similar theme, you can get an Ampeg PF500 with two fliptop PF115E cabs for the value of that B15S.

[ampegfuzz]

Have you tried the guitar setting and boosted the bass control? Also don't be afraid to try the different inputs on the head and the other channel. I owned one for a bit and absolutely love the head. Mine had a Altec 421a in it and it was a little tired. I put a EV EVM15L in it and i liked it a lot.

[auftakt]

Thanks for the input fellas!

Had a rehearsal last night and really managed to find some settings that I loved. I think perhaps I was a little bit too hasty in wanting to make any changes to this amp. with the treble at about 2 o'clock and the bass at 9-10 o'clock I managed to get a tone that I really liked. Also, and much more importantly, I was experimenting with changing my technique a little to coax the kind of tone I am looking for out of the instrument. I was getting all sorts of tones by just adjusting my right hand. More punchy mid-range tones, more scooped out growly tones.

Bass 45, I don't think I would do that ever. I think MAYBE I would trade it for someone's V4b, but that's about it. Tubes for me thanks.

ampegfuzz, yeah I have been playing with the different inputs. The guitar setting feels slightly different to me, like too peaky or barky or something. I much prefer the "flat" setting. The bright channel is kind of nice though. What I'm reeeeallly looking forward to doing - which I can't do right now because it's too loud for jamming - is hook up my switch pedal to switch between the 1 and 2 channels. I intend on cranking the 2nd channel and punch into it for super fuzz bass tones!

I'm going to spend some more time with this amp the way it is!

Cheers guys

[Bassmec]

For your cabinet I would highly recommend you try and find an old Altec
418 series II with the stepped alnico magnet, rather than the 421 with the ceramic magnet.
I have an old Pair of SVT 115's with those options in and they are not boomy at all. They have fantastic mid and upper mid response but enough real low bass to keep me happy.
Sort of like half way between a JBL K130 and a K140.

If you can read it, check out the SPL, how efficient is that then.
Also you see they come from that time when Altec guaranteed them for life.

[ampegfuzz]

I jump channels on my SVT. Something fun and simple to try without that switch box your thinking of trying.

[auftakt]

I have a switcher on my guitar pedalboard, so it's not like I'm hunting for one. Besides the idea is to use the second channel as a distortion effect - not something that's being heard all the time, e.g., hit switcher to switch from normal tone to fuzzed out tone, and vice versa. Should be pretty cool!

Bassmec, thanks for the tips. I will keep that speaker in mind. Sounds like what I'm looking for.

[ampegfuzz]

Yeah it's a cool amp. I kinda miss mine. Those 7027 tubes have a magic about them.