Need more volume!

Skip the new amp and get another cab like the one you have.

 

I agree with hdracer, get another cab. I recently had an outdoor gig and with my two 1x12 cabs I was impressed by how well I could be heard. I had the amp set the same as for a bar gig but I barely had to play the strings.

 

Yep. Double up on cabs. Get another of the same one. More head running into the same cab isn't going to net you any volume gain. The head isn't farting out. The CAB is. But the head has plenty of juice to power another cab. And, unless you want to spend some major coin on one cab that will weigh less than 50 pounds and pound out enough air to get the job done outside, it would be best just to grab another cab for those gigs. (Those cabs do exist, but not for cheap.)

Also, you are asking a lot of ANY bass rig to handle filling the whole universe with sound outside. If you are going to do outdoor shows, it would be best to run through PA subs. Price your band in a way that you can afford to rent them if you don't own them. You of all people (booking festivals) should know that a rig on stage isn't designed to be the FOH bass sound. That is what subs are for. I have never done an outdoor show with less than two 2-18 JBL subs pulling about 3000W each (at least).

 

I added the NY151 cab to my Berlin combo and have 500 watts into 4 ohms/2 -15s and love it. Get the 2nd cab-you won't regret it.

 

Yes, 2 cabs for the win.

Think about it, you were already farting out, that's too much power for the cab. Getting a more powerful amp will add precisely zero headroom.

Zip, nil, nada, less than squat diddly.

 

Doesn't matter. If you run two 8 ohm cabs that will put you at 4 ohms total load. That amp is 200W at 4 ohms. I run an Ampeg V4 at 100W and it will take the skin off your face driving an 8-10 cab. The 4-10 I usually run with it has 4 200W speakers (800W total rating) in it, and again, it will break your knees if you stand in front of it.

Watts is just a number. Don't get all caught up in it. The 400RB is one of the most efficient amps I have ever heard. Trust me, it will power those two cabs just fine.

 

Thermal cab ratings don't say much about how much power it takes to fart out on a low note.

Amp ratings on oldschool amps are RMS with little to nothing of distortion. When you hit your hardest note you can get double the 4 ohm power for a shot burst. Combine that with excess cone travel on low notes and you get fartout, no problem at all.

With two identical cabs you can use same amount of power without any cone distortion. It's a helluva thrill.

Afaik Don builds cabs individually to order so the other cab may not be identical enough to pound clean and really clear but probably won't disappoint you. Search mixing cabs phase.

 

Human hearing isn't very sensitive in the deep bass region, so you need a lot more power to hear those frequencies. The amp will not only produce more power with another cabinet, the added cone area/volume will produce more output.

The power handling of a cabinet is only for matching with the amp's output, so the thermal power handling capability of the cabinet isn't exceeded. It has absolutely nothing to do with how loud it will be.

 

You mean, using the other jack? No- they're wired parallel and it's the reason the amp shouldn't be connected to two cabinets that result in less than a 4 Ohm load (two 4 Ohm or one 4 Ohm and one 8 Ohm cabinet).

How did you set the controls? if you use the master volume set high and control the actual level with the input volume control, it should stay clean, assuming the bass control isn't jacked up. Turn the Boost control down, or maybe to about 2. If it farts out, use the low cut and boost the bass to about +2 and use the mid-bass control to boost that range- it's much easier to hear these frequencies, especially if you're standing close to the cabinet.

 

I'd agree about the more cabs statements here. I'd go for a matching cab of the one you have. If youre going to grab another head, may I suggest a higher powered RB series head by GK. You already have exp with the 400, and I can tell you from exp that the 1001 RB or 700 RB rock. The 1001 RB, which I have, will get that clean headroom for days you were talking about. A lot of punch and clarity. And headroom. But then, OTH, you would almost def need to get another cab. Not sure if that was the direction but me, thats what I would do. I like the fact I have some extra headroom in my amp and to know that if I needed to, I could just buy another 410 and thats all I'd have to do, is just get another cab, if I needed to be louder. And my head wouldnt have any issues pushing it.

 

Yep, additional displacement is the key. Outdoors can be brutal. I've read that for PA gear, many times the rule of thumb is increasing displacement by a factor of 5. Now I don't know that to be absolutely true, but the point is that significantly more Vd is needed outside to sound approximately the same as inside. Of course the size of the outdoor venue is a m-a-j-o-r consideration, too, bigger spaces needing more displacement.

If you want to pick up a new amp, fine too, & the TH500 is great, but what you really need is a lot more air movement. If your LDS 115 employs a 3015 or 15PR400, one more will go a long way in making the outdoors feel more at home for you.

 

What are you waiting for then ? Grab it before it gets away.

 

When you get the second cab, wire both together with a 1/4" phone speaker cable. then connect a second cable to one cab and with a 9V battery touch the tip to the positive and the sleeve to the negative. Both cones should move out away from the magnets. This will check if the cabinets are both wired with the same polarity. If they are then they will work together well.