Eminence Legend B102 DIY Cab Help?

You have discovered one of the challenges to designing a cabinet that respects the mechanical power handling of the speaker. It's a very real issue for us designers.

Now the bigger problem, or the other limitation which makes the mechanical power handling more of an issue is the low sensitivity. This means that you will bump up against the mechanical power handling limitation more often.

The number you arrived at seems a little low though, you might go back and double-check that you have all the numbers entered correctly (including the correct units for each number). I don't use that program, but I will go back and maybe hand calculate a few data points when the results don't match what I expect.

 

You're not making a big deal at all. That driver just isn't good for electric bass. The reason is the short xmax. You'll never handle low C with enough output unless you're using at least two if not four of them. The Beta 12LTA would be better, but I wouldn't be asking even a twelve with less than 4.5mm xmax to handle low C.

 

Simple answer... you can't compensate.

 

Are you using the latest version of winISD pro? The not pro version is buggy.

 

It's not software it's 102 driver. Older version is buggy with newer operating systems. But still works fine. New version is compatible with newer operating systems. Thats it. Nothing new and special. Same formulas same functions

And yes the 102 does like a large cabinet to get flat response. But as you found power handling is horrible in such large volume.

Happy medium with the 102 is around 1.3 to 1.6 cubic feet and keep the tuning around 48 to 50hz

Its about all you get with 102 and as mentioned sensitivity is low. Best application is 2x10 pair if you want power handling . with a pair you can do about 1.3 cubic per driver and tune 45 to 48hz

Realistic F3 in 1 cubic will always be 65 to 75 hz regardless of driver with musical instrument type speakers

More to be gained in 2 cubic like you found but efficiency and bandwidth at that point is found with a 12" driver its it average typical volume for 12" with 55 to 65hz still being achievable f3

To really dip down a 15" driver in 3 cubic feet brings you closer to maybe 48 to 55hz. Real big boys are your large box 15 inch drivers in 4 cubic feet. And same as well tradeoff off power handling in 4 cubic to maybe touch 48/50hz

With typical Efficiency Bandwidth Product (EBP) of 80 to 100 musical instrument speakers these are typical volumes. And deep F3 only come from ...airspace.

.9 to 1.6 = 10" efficiency = 92/96dB
1.6 to 2.4 =12" efficiency = 94/98dB
2.6 to 3.2 small box 15" = 95/101dB
3.2 to 4.4 large box 15" = 95/101dB

Dont worry plenty EQ in modern amps
And 2nd harmonic in the 80s is more important than the 40hz and is more audible.

It's why your classic peg 810 with sealed drivers only in .9 cubic per driver with F3 maybe at 75hz lol still makes many many players happy. It hits 80 hz just fine. Efficiency per driver and power handling is ok. But it uses 8 speakers so more headroom.

Ive done drop D C and A to absurd levels with 810s but just used 2 of them.