• TalkBass has been independent since 1998. Add your voice.
    Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
    Join free Log in
    Want zero display ads or expanded classifieds tools? Compare plans.

Ampeg replacement Speaker Advise

almorgan76

almorgan76

Supporting Member
Mar 22, 2012
157
42
#1
I recently acquired an Ampeg BXT115HL4 Bass cab. This is a sweet, but heavy full range cab in excellent condition. I was unable to test prior to purchase but I doubt I would have caught the fact that it has a low powered MG 15 in the cab. I was first tipped off by the low output, then the breakup at higher volumes then I notice the cab was 8ohms when measured vs the 4ohm rating. Then I took it appart and found the bad news. Guess someone blew the original and moved the cab for well below market value to me.

Bottom line, I am looking at replacing the driver with probably an Eminence Legend CA154. However, there is an option for just a little bit more for a Eminence Kappa-15. The Kappa has a much better low end frequency (<100hz) response than the legend which is what caught my attention. Generally these are used for more PA applications which may be best for this cab.

Usually a Legend in an Ampeg cab is a no brainer but this cab is intended to be full range as designed in conjunction with Victor Wooten and Steve Bailey. I am sure either way they speakers will make this cab sound great but I am curious to know if the Kappa would be worth the $30 extra for a better sounding cab at the end of the day. Maybe I am just over-thinking it....

Any advise/experience before I purchase is appreciated.
 
#3
I wouldn't use either one. Full range 15"s in Ampeg cabs are supposed to do 4k on the top end, and neither of these reach it. I'd use an Eminence Beta or Delta 15a if on a budget, or a Kappalite 3015 (not the 3015LF) or Faital 15PR400 if you're not. Betas and Deltas are Eminence's most typically Ampeg sounding speakers. But the 3015 and the Faital are very good neo speakers and typically work well in cabs like that.
 
#4
I am interested in this cab being a 8ohm cab and certainly think the Delta would be a good fit. However, going 8 ohms throws off the crossover and tweeter causing me to essentially shut off the tweeter. Not a big deal as I don't utilize much of the top end but it means this cab is no longer trully full range.
 
#5
The Faital 15PR400 is available in 4 Ohms, as well as 8 ohms. :) May require some tuning to get it to perfection, but it could potentially be an option.

Here Ya go!
http://www.usspeaker.com/homepage.htm

Edit- Just looked at an image of the cab. It is shelf ported, so tuning it via changing port tube length is a no deal. You could work up the internal volumes and port area as it is on winisd, to see how it will fare.
 
#9
Here's your other thread on the same thing.

http://www.talkbass.com/forum/f15/eminence-legend-ca154-kappa-15c-916653/

The Betas and Deltas will have a bit more of the Ampeg "voice" (lots of 100hz). Beta will take a little more power before fartout, Delta maybe little nicer topend? JimmyM would know.

As for the other, the Legend will be a little warmer (less treble), higher spl and higher excursion, meaning it'll play a little bit louder to start with, although that can be tricky to the ear. It's lowend rolloff is a lot smoother and won't put put out quite as much 100hz in comparison to the other frequencies. It'll also take more power than the others and turn it into sound.

The Kappa has xmax and Vd 1/2 of the Legend, it'll fart out early and is likely the poorest choice of everything mentioned here.
 
#10
JimmyM said:
I thought you could get 4 ohm Betas or Deltas. Not anymore?
Click to expand...

They used to make I think a 16ohm Beta, at least in the 10" variety. Was looking for some to load up an old 210 and found out they stopped making them. I don't know if you can still get 4 or 16 ohm recone kits and get there that way.

"Cheap but decent" 8ohm 210 is pretty hard to come up with now with off-the-shelf stuff. As far as I know, there is no 4ohm Beta 15 anymore.
 
#11
With a cab volume of 1.9902 cubic feet and the square ports dimensions I was able to come up with an approx tuning of 53Hz with the calculator located it the following link.

Link Removed

What T/S values are most critical to ensure the selected driver works well in this cab, assuming the difficulty in making changes to the port?
 
#12
FWIW, I'll try to help as much as I can. Someone with more knowledge can correct Me if I'm missing anything or can explain it better.
From what I know,T/S parameters that are pretty critical to proper enclosure type and size are:
Resonant Frequency (fs)
Comp. Equivelant Vol. (Vas)
Total Q (Qts)

Also, It would probably help You a lot to read up on it a bit more here:
http://www.diyaudioandvideo.com/

From the specs You listed from the cab (internal volume, tuning), and out of everything that everyone has mentioned (allowing You want to stay with a 4 Ohm speaker), IMO- there are two speakers that would potentially work pretty well in it as it is.

Again, My first choice would be the Faital 15 PR400 (4 Ohm), or (if You wanna save some cash and dont mind the added weight) the Eminence legend CA154.
From the winisd-online version (rough, but it's all I have available here at work), both drivers in that cab show a slight bump in the 100hz range, which is far better than some of the other options looked.
 
#13
Lets see if I have figured out how to upload this photo.....this is the measurements/calculations I have for this cab.
 

Attachments

  • BXT115HL4.jpg
    BXT115HL4.jpg
    44.1 KB · Views: 71
#14
Combination of the smallish box and high-ish port tuning will make the Betas and Deltas really boom. Lining the box and lowering the tuning will help that some. From your diagram, it looks like you could block off maybe 1/4 to 1/3 of the port without getting into noise problems. You'd want to maintain some of the 100hz bump to keep the ampeg sound, but as is, it may be crossing the threshold from fat tone into boomy, one-note-wonder type stuff. The Legend or Faital won't have the boom issue, bit I'd still want to push the port tuning down to 50hz or a little lower if you play any 5-string, or down tuned 4-string stuff.
 
#16
It doesn't seem like much, but it might be just enough to keep it from unloading on deep notes with power behind them. You can't really tune it any higher without breaking out the saw, so, could just try temporarily blocking off a little port at a time and tune it by ear. If you like the sound and it doesn't distort as is, that's cool. Just that dropping the tuning a little will help keep the cone under control on loud, low stuff.
 
#17
will33 said:
It doesn't seem like much, but it might be just enough to keep it from unloading on deep notes with power behind them. You can't really tune it any higher without breaking out the saw, so, could just try temporarily blocking off a little port at a time and tune it by ear. If you like the sound and it doesn't distort as is, that's cool. Just that dropping the tuning a little will help keep the cone under control on loud, low stuff.
Click to expand...

Hey Will, would I be correct in saying, that He could actually extend the shelf port a bit and lower the tuning as well?
If that is the case, it wouldn't be that hard to achieve a more optimum tuning, by say adding measured length of plywood to the port shelf on the interior of the cab.
 
#18
JMac4strngr said:
Hey Will, would I be correct in saying, that He could actually extend the shelf port a bit and lower the tuning as well?
If that is the case, it wouldn't be that hard to achieve a more optimum tuning, by say adding measured length of plywood to the port shelf on the interior of the cab.
Click to expand...

Yup. That's actually the better way to doit so as to not lose any port area, but, just eyeballing his diagram from my phone, it looks like the port is already pretty close to being it's own heights distance from the back, so, you'd have to start making it climb up the back wall.

Being that you have to subtract the space the port occupies from the internal net volume of the cab, you'll hit a point of no return there somewhere where you can't tune the small box any lower, so, reducing port area is the next best thing, if you have enough to spare and the air velocity will stay low enough to not chuff.

Easier to just block some of it off for one-off listening tests/adjustmemts too.
 
#19
If you play with the numbers in a box calculator program, you'll find that 2 cu.ft. is pretty small to get a lowish tuning and keep enough port area for a 15 with much excursion capability. You can find something that'll work but it'll be a bit of a juggling act. That box is actually a really nice size for a ported 112 or a sealed 115.
 
#20
I think this box was actually designed to be "punchy." I recall Wooten usually playing in a more lead bass style with less bottom needed. With the MG in the cab at low volume this box sure punches well for a single 15.

I appreciate all the help! It certainly has been a learning experience. I suppose I will just be cheap and get the Legend CA154. If I don't care much for the sound I will just build my next one! ;o) I am already thinking about building a 12in for portability.
 

Latest posts

Top Bottom
Back