Would 150 watts be the same loudness, same amp but thru larger speakers?

[don21480]

I have a Markbass Minimark 602 and I'm wondering if the newer Minimark 802 would be the same loudness since they have the same exact wattage at 8 ohms? On the surface it seems that they would be the same but there is so much I don't understand about amplification! Thanks!

 

[JimChjones]

Probably not.

The trouble is watts are not a measure of volume, in the amplifier situation they are a measure of electrical power which may be measured in radically different ways to get radically different numbers. Then beyond that the speakers themselves may deliver quite different volume from the same power. This can be handily demonstrated by making up a cable to connect a separate bass speaker up to a headphone output and comparing the volume to headphones...

With the same manufacturer we can hope they measure their watts in the same way, and with similar models the sound delivered with the same characteristics, but the specs on the Markbass website I found list the sensitivity of the 602 at 98db and the 802 at 99db, which AIUI means that the 802 is going to be a tad louder, but maybe not enough to be readily audible.

 

[Downunderwonder]

Without looking at any specs myself, just Jim's numbers, you get 1dB extra loudness on paper.

 

[Sparky Mark]

I would expect the 2 × 8 combo to be discernibly more capable than the 2 x 6. The surface area of the speakers is directly proportional to the square of the cone radius. This gives the 2 x 8 combo approx 80% more cone area. We would all expect a 2 × 12 cab to be more capable than an equally specified 2 x 10 wouldn't we? The difference between the 8 and 6 speakers is even greater than that between the 12 and 10 inchers. The amount of air moved is directly proportional to the speaker cone's surface area. The 2 x 8 combo is also physically larger so potentially more capable at lower frequencies.

 

[ThisBass]

Would 150 watts be the same loudness, same amp but thru larger speakers?

any other things beeing equal you'll get about +3dB of loudness by doubling the speaker cone surface.

 

[don21480]

OK so it seems that really not a lot of difference - now adding a 2nd 8ohm cabinet would reduce the total ohms to 4 and then the wattage and loudness goes up?

 

[Downunderwonder]

Would 150 watts be the same loudness, same amp but thru larger speakers?

any other things beeing equal you'll get about +3dB of loudness by doubling the speaker cone surface.

When did you get all simple? Sensitivity trumps surface area, all else equal.

 

[ThisBass]

When did you get all simple? Sensitivity trumps surface area, all else equal.

with any other things beeing equal any improvement of surface cone area improves radiation impedance.
That's nothing but pure acoustical science consideration.

 

[Downunderwonder]

with any other things beeing equal any improvement of surface cone area improves radiation impedance.
That's nothing but pure acoustical science consideration.

How do you get around a sensitivity deficit?

 

[ThisBass]

How do you get around a sensitivity deficit?

something else is not equal.
That's how science works.

 

[Downunderwonder]

something else is not equal.
That's how science works.

The only way I know how to get around a sensitivity deficit is to throw more power at it but that was excluded in the OP.

 

[ThisBass]

The only way I know how to get around a sensitivity deficit is to throw more power at it but that was excluded in the OP.

He asked the question what would happen with "larger" speakers.
Any other things beeing equal he will get +3dB of loudness with "doubling" the speaker cone surface.
Again, that's well known knwledgement based on acoustical science considerations.


He could also trade off SPL improvement for better low end response with a larger speaker.

 

[Downunderwonder]

He asked the question what would happen with "larger" speakers.
Any other things beeing equal he will get +3dB of loudness with "doubling" the speaker cone surface.
Again, that's well known knwledgement based on acoustical science considerations.


He could also trade off SPL improvement for better low end response with a larger speaker.

The OP cab with the larger speaker area has only 1dB more sensitivity and the same nominal impedance presented to the amp, same power handling. 1dB extra loudness no?

 

[Omega Monkey]

Down, is that 1db coming from an educated guess or some published specs somewhere?

Almost universally, larger speakers of the same design (ie they're just proportionally bigger and that's it) will have higher sensitivity, and will go lower.

In this case, a 2x6 is a pretty damn small cab, which I wouldn't expect to get really above bedroom to coffee shop levels. A 2x8 as mentioned is almost 80% more cone area. I dont know if it's possible to figure out a sensitivity curve (ie if doubling area gives you 3 db, where do you hit 1db and 2 db?), but I would guess you'd get at least half of it in broad band terms, and possibly a lot more in the low end (where it's going to be most noticed).

So in real world terms, I wouldn't necessarily expect it to be perceivably louder, but I WOULD expect it to be perceivably fuller sounding. Having said that, I don't think the increase would necessarily be worth it depending on your aims and your budget. If I had the 2x6 and needed more volume for some things, I would be inclined to do a bigger jump to a 2x10 or bigger, and keep the 2x6 for home practice and very low volume situations. But you can get 2x10s these days that weigh about as much as 2 basses in hardshell cases. The added utility vs cost vs volume of anything much smaller than that is questionable at best. A 300-500w 2x10 can cover quite a bit, cost less than $500 brand new for a pretty nice one (or an amazing used one), and fit in the passenger seat of a porsche 911.

Of course maybe you already have a bigger cab and the 2x6 is just too small to be usable for you, in which case replacing it with the 2x8 might make sense.

BUT, the Trace 2x8 is rated 500w and is a pretty great sounding cab (although surely different than the MB, since it doesn't have a tweeter). It's got a bit of a vintage vibe without a tweeter, but it's also a 2x8 so it's still got plenty of highs. And if you used flats you wouldn't be getting anything from a tweeter anyway (not that was very usable at least). They're not exactly cheap though. But they are something like 28 or 30 pounds (maybe less?). And rated at 500w. So 2 of them could probably handle just about any bar or small club gig with a 300-500w head.

 

[JimChjones]

Down, is that 1db coming from an educated guess or some published specs somewhere?

As I posted it's from data published on the Markbass web site.

 

[JimChjones]

now adding a 2nd 8ohm cabinet would reduce the total ohms to 4 and then the wattage and loudness goes up?

In theory yes. But it depends on the second cabinet. It also depends on how the sound from the two cabinets interacts and how the amp is wired up.
Looking at the manual for the amp I'd be inclined to have a single 4ohm extension cabinet and turn off the internal speaker rather than have the possibility of odd effects out in the room from two cabs of different characteristics fighting. Markbass don't appear to do a matching 2x6 or 2x8 cabinet to precisely complement the combo.

 

[Sparky Mark]

Returning to the OP original question of would the 2 x 8 version of this particular combo be louder than the 2 x 6 version?; the increased cone area allied to a larger physical volume cabinet will enable it to go louder and deeper.
When (why) did we all get complicated?

 

[JimChjones]

Why are we still theorising about cone area and cab dimensions when the actual manufacturer's published performance figures of the two units are available?

 

[ThinCrappyTone]

 

[knumbskull]

Completely uneducated non-science answer: adding a 2nd cab is *probably the most straightforward* way of getting more real-world volume.

Now i’m going to run away before someone posts a bunch of stats proving why i’m wrong