How much will another 1x15" increase my volume by?

[dubhnight]

I'm currently running a single 1x15 cabinet with a Bugera 1960 tube amp, which is rated to around 100w/150w. This is really really loud when it's run into heavy breakup, but at a volume where the bass is still reasonably clean, it just isn't loud enough for what I'm trying to do.
My question is, how much louder can I expect my rig to be if I put in another matching 1x15 cab? These are cabs I've built myself, so it might be difficult for you guys to know what I'm trying to work with here, so all I can say is that they're quite large, ported, and bass heavy cabs, with some efficiency sacrificed for a deep rumble.
On a side note, I would recommend the Bugera to anyone who wants a nice, reasonably inexpensive all tube rig, but doesn't need bring buildings down with volume. The tone is fantastic, it's got a really lovely midrange with a nice vintagey muted high, and plenty of low end. Quite flexible as far as different tones are concerned too, you can get a lot out of it by mixing the channels.

[Bassmec]

Originally Posted by dubhnight

I'm currently running a single 1x15 cabinet with a Bugera 1960 tube amp, which is rated to around 100w/150w. This is really really loud when it's run into heavy breakup, but at a volume where the bass is still reasonably clean, it just isn't loud enough for what I'm trying to do.
My question is, how much louder can I expect my rig to be if I put in another matching 1x15 cab? These are cabs I've built myself, so it might be difficult for you guys to know what I'm trying to work with here, so all I can say is that they're quite large, ported, and bass heavy cabs, with some efficiency sacrificed for a deep rumble.
On a side note, I would recommend the Bugera to anyone who wants a nice, reasonably inexpensive all tube rig, but doesn't need bring buildings down with volume. The tone is fantastic, it's got a really lovely midrange with a nice vintagey muted high, and plenty of low end. Quite flexible as far as different tones are concerned too, you can get a lot out of it by mixing the channels.

You will get about the same increase in apparent loudness as if you had doubled the output power of the amp.
That's +3dB at least, if they are stacked and the drivers are close coupled.

[walterw]

plus it'll put the top 15 closer to your ears, also making it apparently louder.

it's the obvious next step here (assuming you're building them identical and that you're building them right, with the correct math for the box and the speaker and all that.)

[RickenBoogie]

+1 assuming your cabs are built and designed to optimize the selected drivers, you gain 3dB, which is significant. Since you say the cabs are bottom heavy, you might want to eq some of the lows out, and push your low mids up. This will also help get louder.

[dubhnight]

Excellent, thanks for the advice. This'll be the next thing on my agenda then. Just, while I'm asking, would it be advisable to maybe add another smaller driver while I'm at it? Like, I see people talking about certain cabs using a 15" and a 6". Will this boost my volume by much? Will it kill my vintage tone? (I know tweeters don't work well with tubey overdrive) Will it be worth the extra expenditure on the driver and crossover?

[emblymouse]

I just went that route and I'm back with full range 15's and 12's. The 6" if crossed over properly is much easier on the ears than most horns, but it is still way different than what you are used to hearing. Not a traditional vintage'y sound.

[Russell L]

When I got my second 15 I was impressed with the difference. You may notice some sub lows that you hadn't noticed as much before.

[christw]

With a 100w tube amp you probaby should have sacrificed low end extension for efficiency. Just my opinion...

Like everyone else said, it will be noticably louder, especially on the deep side. That said, using 6550's in those amps can really fatten up the low end but won't really increase the headroom.

[dubhnight]

Originally Posted by christw

With a 100w tube amp you probaby should have sacrificed low end extension for efficiency. Just my opinion...

Like everyone else said, it will be noticably louder, especially on the deep side. That said, using 6550's in those amps can really fatten up the low end but won't really increase the headroom.

Yeah, haha, I would say so too, if only I had known at the time. I built the cab a while ago before I had this amp. Still sounds great though. You can get a good bit of midrange bursting out with the Bugera anyway I find.
And really? Do you know if there are any particular brands that would sound good as far as 6550s are concerned?

[will33]

Originally Posted by dubhnight

Excellent, thanks for the advice. This'll be the next thing on my agenda then. Just, while I'm asking, would it be advisable to maybe add another smaller driver while I'm at it? Like, I see people talking about certain cabs using a 15" and a 6". Will this boost my volume by much? Will it kill my vintage tone? (I know tweeters don't work well with tubey overdrive) Will it be worth the extra expenditure on the driver and crossover?

Depends on the crossover design and the particular small speaker used. No, it won't sound the same, but can still easily sound "vintagey".

Might I suggest using a sturdy bass woofer with a guitar speaker taking the mids and highs?



+1 to giving up a little "deep rumble" in exchange for more spl when using <300 watt tube amps.....or at least <200 watt.

[bgavin]

At the same volume knob setting (voltage), you will get +6db if wired in parallel.
This is +3dB from the doubling of the cone area, and another +3dB from the increased power draw.

If you have access to an RTA, this is easily measured.

[hdracer]

I use a Fender Bassman 100T (25W-100W) with 2 3015 loaded cabs.

I get close to the same volume at 25 watts with both cabs as I get with one at 100 watts. The way it fills a room is sweet.

[Bassmec]

Originally Posted by bgavin

At the same volume knob setting (voltage), you will get +6db if wired in parallel.
This is +3dB from the doubling of the cone area, and another +3dB from the increased power draw.

If you have access to an RTA, this is easily measured.

Its a tube amp with an impedance matching output transformer so there is no more watts available by reducing the impedance.
Get a grip!

[will33]

Originally Posted by bgavin

At the same volume knob setting (voltage), you will get +6db if wired in parallel.
This is +3dB from the doubling of the cone area, and another +3dB from the increased power draw.

If you have access to an RTA, this is easily measured.

The Bugera thing he has is a 100 watt Marshall clone tube amp, so no additional current draw? There is some added coupling in the bottom from multiple drivers though, yes?....beyond the standard 3db? Never really understood that, but it sure sounds and feels like it. Something about a little extra bit below whatever frequency the center to center driver distance is?

[walterw]

Originally Posted by dubhnight

...while I'm asking, would it be advisable to maybe add another smaller driver while I'm at it? Like, I see people talking about certain cabs using a 15" and a 6". Will this boost my volume by much?

you'll notice they also talk about very sophisticated hand-built crossovers, carefully-tuned cabs and crazy-deep high-excursion 15s that only do sub-bass frequencies.

so no.

[Pbassred]

This is really really loud when it's run into heavy breakup

Are you sure its the speaker that is breaking up?

You will get about the same increase in apparent loudness as if you had doubled the output power of the amp.
That's +3dB at least

3db is a doubling of power but not volume. Its noticeable but not an awesome change. To achieve a doubling of percieved VOLUME requires 10 times the power.

Some people have already said that you can't do it with your head but for those thinking about doing this with their solid state amp. What you mostly achieve is a hot, stressed amp.

[walterw]

right, ~ +3 comes from doubling speakers or power, but neither one results in doubling the volume.

who said he couldn't do it with this amp?

assuming it's an 8Ω cab, how would doubling the cab for a 4Ω load "stress" any normal bass amp?

if anything, being able to back that tube amp off a little to get it out of its distortion range would mean less stress on it, not more.