Rig Advice Needed

[Green Mind]

Hello, all

I hate to make this type of thread with all the well written FAQ links floating around, but I just wanted to get a little confirmation before dishing out the cash for new equipment.

So, I'm looking to add another cabinet to my setup. Right now I'm running a Marshall MB450H into a vintage Traynor 15" cabinet with the speaker replaced with a Eminence Kappa Pro 15a (500w at 8 ohms).

Link to each's specs:
Marshall Amps :: MB450H
Eminence Kappa Pro 15A, 15" 8 ohm 500W - Sound Speaker Repair

While I'm happy with the sound, I'm really just looking for more volume. My local music store really doesn't have much for a bass amp selection but I did see an Ampeg B-115E that seems reasonably priced for my budget at $290.00 new. The cabinet is rated at 200w at 8 ohms so paired with my current cabinet and amp that would be 300 watts at 4 ohms. With the one cabinet rated at 200w and the other at 500, will there be a major volume difference or just once I push my amp a little harder than the Ampeg can "handle" (potentially overdriving it I guess).

Here's the cab by the way: Ampeg: B Series - B115E

Would this be a decently functional setup? I'd really like to go for the two cab route and save some money by using my existing as well. Would this be too minimal of an upgrade to my rig for a real difference in volume or would I be better off biting the bullet and saving up for a couple of 4 ohm cabinets instead.

Thanks in advance and I apologize if this is just a long winded, redundant thread.

[RickenBoogie]

While the pairing may not be ideal, I think it should be mostly fine. The problem you'll encounter is that the Ampeg cab will be different in every way, tonally, power handling, and so forth. But, so long as you don't push it too hard, you'll get what you want out of it.

[HolmeBass]

The wattage rating of a cabinet does not determine its volume level. The efficiency, or sensitivity, does. Both of those cabs are 1x15's, so I think that would help mitigate phasing issues between them, I think it could be a good match. Both cabs 8 ohms, they will each get 150 watts, should be good to go. Look for "X dB @ 1W/1M" type specs to try and get a handle on the cabs' relative volumes, but really you're going to have to try it out to get the real story.

[Green Mind]

Originally Posted by RickenBoogie

While the pairing may not be ideal, I think it should be mostly fine. The problem you'll encounter is that the Ampeg cab will be different in every way, tonally, power handling, and so forth. But, so long as you don't push it too hard, you'll get what you want out of it.

I just wonder if the Ampeg's additional speaker will give enough of a difference in volume to merit cutting back on my volume knob for it. I've been pushing my current cabinet pretty hard. I guess I'll just have to try it, but it's tough to determine what seems good in a music store compared to a band setting.

Originally Posted by HolmeBass

The wattage rating of a cabinet does not determine its volume level. The efficiency, or sensitivity, does. Both of those cabs are 1x15's, so I think that would help mitigate phasing issues between them, I think it could be a good match. Both cabs 8 ohms, they will each get 150 watts, should be good to go. Look for "X dB @ 1W/1M" type specs to try and get a handle on the cabs' relative volumes, but really you're going to have to try it out to get the real story.

I realize that watts =/= volume, I'm just more concerned with the technical stability of the different ratings since I'm not totally certain. I have read that despite a popular choice, something like a 4x10 + 1x15 may create volume differences and phasing issues and that's exactly why I'm looking at another 15. I'm definitely going to try the ampeg with my head and cab before buying.

I'm starting to lean towards going for a two 4x10 setup instead for more speaker area but I might as well give the two 1x15s a shot first.

Thanks for the responses!

[Gearhead17]

Originally Posted by Green Mind

I'm starting to lean towards going for a two 4x10 setup instead for more speaker area but I might as well give the two 1x15s a shot first.

Thanks for the responses!

The two 410 setup is good for just about anywhere. The two 15 setup can also be really good too depending on your tonal goals. Identical speaker pairings are the way to go.

[thisisausername]

The speaker in your old cab will respond at a different speed than the speaker in the ampeg and it may or may not be a problem, you could en up with a really annoying echo/chorus type thing that sounds awful, try it with your rig first though, it might work

[kb9wyz]

I've read some posts from people who have had good luck running a pre into some big old power amps with nice big, well matched cabs. If you have an XLR out on your cab, you could use it as a pre. Just thinking out loud.

[fingerbun]

Originally Posted by HolmeBass

Both of those cabs are 1x15's, so I think that would help mitigate phasing issues between them,

Huh, I don't understand this . Any more detail you can add?

[kb9wyz]

Originally Posted by HolmeBass

The wattage rating of a cabinet does not determine its volume level. The efficiency, or sensitivity, does.

To be fair, efficiency does not produce volume, electricity does. So we do really need both efficiency and wattage to figure out the volume of a cab.

It might be fun to look at the sensitivity of a lot of drivers and see how much the numbers differ, on average. Could be productive. Or an epic waste of time. But if it turns out that, for example, the 10 most commonly used 10" drivers have a 91dB +/-1dB sensitivity, then we could kinda scrap concerns over sensitivity and rely on wattage as a reasonably accurate guide. Or at least a rule of thumb. But I feel you. I have seen a number of combo amps where one had X power and Y sensitivity whereas another had twice the power and 3dB less sensitivity. So the difference was pretty much only in price.

I don't know. What do you think?