Sub sealed Box size plus LT and PEQ

[thymej]

I have always heard that sealed boxes tend to be more musical compared to ported. I have also read that a sealed box Bessel alignment (0.577) also tends to be more musical (perhaps because of the better group delay and all the other gobbledy-gook).

My question is, when using a Q of 0.577 in a sealed box and a LT plus PEQ on a sub, do you still get the benefits of the larger box (better group delay and what ever else of the gobbledy-gook stuff that makes it more musical)? Or does the PEQ and or the LT circuit defeat the larger box benefits (musical)? I’m asking this because my plan is the make a sealed box with two 15” drivers with a Q of 0.577. The box gets kinda big with that alignment plus two drivers.

The drivers am lokking at are Dayton titanic 15 MkIII or TC9 (Soundspliter rl-9 or the like), I want the more musical driver.

ThymeJ

[KeithM]

When you get the drivers for LT, get the biggest xmax you can find and play with winISD for it. Also, when you put the LT on, you change the Qtc too. Also, have you looked at the Ascendant audio arsenal?

[SteveCallas]

What is a commonly accepted good Q for a sealed design? I figured for shits and giggles I may try blocking my port to see if there is any difference in sound with such a large enclsoure - the Q comes out to be 0.565 - is that generally accepted as good?

[KeithM]

my sub is rigth around there and I think it sounds good. I haven't tested it in a higher q box however.

[steve nn]

I may try blocking my port to see if there is any difference in sound with such a large enclsoure

Now I don't know about your sub Steve, but every time I've tried that in the past (with many subs) it turned out to be one of the poorest representation of a sealed sub that I can think of. :lol:

[ThomasW]

Steve your tube is really too big to significantly benefit from a LT.

Qtc of 0.565 is great IMO. Dial in some standard boost with EQ and see how it sounds. You'll probably find it doesn't have as much "punch" as you're used to though.....

[SteveCallas]

I may try it just as an experiment with music to see if there really are any noticable sound differences, no desire to keep it sealed - the differences in group delay, phase, impedance, and cone excursion between ported and sealed in this enclsoure down to 30hz are negligible, so I'm wondering if other factors may still lead to a difference.

[thymej]

...You'll probably find it doesn't have as much "punch" as you're used to though.....

Would the less punch be becasue the sealed does not go as low then when ported within the 3db mark? Or does sealed boxes start to lose some punch when they get to large?

[ThomasW]

Sealed boxes don't get the boost in output from the port.