Custom Ampeg 2x15 Help

[gimp]

So I've hinted around in other threads about what I'm doing. As I'm about to put everything together physically, I want to run some final ideas and plans past everyone. Feel free to comment, call me stupid, praise me for my amazing idea... whatever.

Background:
My home rig is a 1967 B-15N.

My "stage" rig is a 1967 BT-15 (sensing a theme?) through a Mosvalve MV-962 power amp (80 watts per channel @ 4 ohms, two channels) hooked up to a ported 8ohm 1x15 (which is for sale, btw) running one of the channels.

It sounds AWESOME for what I want. I A/B'd it with my B-15 and it is on point. It is loud enough for the practice spot, but not quite enough for stage volume without really pushing things hard. So if one channel running a 15 is good, the other channel running another 15 is even better!

What I've Got:
I have a cosmetically rough Ampeg V4 guitar cab with a blown speaker or two, some carpentry and wiring skills, and the internet.

The Plan:
I plan on removing the speaker board from the V4, and add a new one converting it to a 2x15. Each 4 ohm 15 will be in it's own "chamber" inside the cab.

I also plan to wire it up so each 15 can be run separately. This lets me use all of my power amp (both channels) for gigs, and only one speaker for practice.

I've also figured out a wiring scheme that will also let me run both together at an 8 ohms load.

This is the diagram.



The Questions:

- How does the diagram look? (I've asked before, but I'm looking for confirmation)

- Porting: I'm trying to replicate the Portaflex sound as much as possible, so I originally thought about porting both 15s. Is there value added in only porting one, so I can blend tone between the two speakers?

Thanks!

[JMac4strngr]

Just a guess based on the V4 Guitar cab that I own. I wouldn't think it'd have enough internal volume for two 15's used as a bass cab, as well as the baffle not being large enough. You can measure the internal volume, and model it in winisd with the speakers of Your choice to see how it's gonna do. I wouldn't expect too much though.
If You're wanting to go the DIY route You could build two TL606's on the cheap, and come out better. However, If You're pockets are a bit deeper there are other more Hi-performance DIY cabs out there (Fearful, and the like).

Have You thought about buying two of the new PF-115 cabs? They look and sound pretty tasty, and the price is good as well.

[gimp]

The internal volume is a concern of mine. Some of it comes down to "what you got". I already have the new speakers and the cab. I was just looking on how to marry the two together.

[stiles72]

How about pick up some plywood from home depot and build a clone of your BT15C cab? I have a BT15C , and in some ways dig that over my '63 B15

[skychief]

schematic looks kosher to me. The "blending" of ported vs non-ported is questionable, tho.

[gimp]

Originally Posted by skychief

schematic looks kosher to me. The "blending" of ported vs non-ported is questionable, tho.

That's what I was wondering about. I think both will end up ported.

[gimp]

I forgot to mention, the speakers I have on the shelf for this project are Eminence Legend CA154s.

Size wise, the V2 visually appears to have the same volume as the B25B, which is why I thought it would work well enough.

[skychief]

keep us posted as to what you do!. *fingers crossed*

[Robby Hoinsky]

You're likely going to be choking those 15"s in that airspace. You'd probably be better off using just one. What's the internal dimensions of the old 4x10? Is it sealed back?

Robby

[gerryjazzman]

Check out Eminence's cabinet designs for that driver:

http://www.eminence.com/pdf/Legend_CA154_cab.pdf

Measure the internal volume of your cab (divide it in half since you are making separate chambers) and comPare that to the Eminence designs. That should give you a pretty good idea of what to expect in performance. Next step would be to model using Winisd.

[throbgod13]

i'd just find a empty 215 cab, instead of cutting up a V4 cab..

the only thing i can think of with the V4 cab (if your really intent on using this cab) is to extend the back of the cab.. using the existing back, make a "spacer" frame to deepen the cab to the correct Vas needed..

of course, going to all of this hassle, you could just build a cabinet yourself and leave the V4 cab alone.. sell the V4 cab to fund the new cab..

[jungleheat]

Don't screw up the Ampeg cab. All that vintage stuff just gets more and more rare all the time because idiots ruin it for no reason just because it's not what they want. So sell it to someone who DOES want it. As mentioned, it's probably too small to effectively be a 2x15 bass cab anyway. Just get (or make) an actual 2x15 cab and mod it to use 2 inputs (guessing that Tube Works power amp isn't bridgeable?).

Just to give you an idea, I bought an old Acoustic 106 2x15 in working condition (maybe a 6 or 7 out of 10 cosmetically) for $75. Even if I spend $300 putting new speakers in it, I've got a sweet vintage 2x15 (with modern power handling) for under $400 that will only weigh about 75 pounds (under 60 if I go with neo speakers).

[sickest beast]

Originally Posted by gimp

I forgot to mention, the speakers I have on the shelf for this project are Eminence Legend CA154s.

Size wise, the V2 visually appears to have the same volume as the B25B, which is why I thought it would work well enough.

They are close. I looked for a V2 but once I found one, I realized it was too small for bass applications.

they are only slightly deeper than the B25B but only about a third as tall. The internal volume has got to be a bit smaller than the B25B, and the B25B is already on the threshold of farting out at high volumes with 2 high power 15s.

But who knows, I've seen Fender cabinets with 2x15s that are the same size as V2 cabinets, so it might sound okay.

Good luck.