Here's what I'm going to do

[simon5]

It's really hard to really compare ported vs. sealed because they are so different.

IMO, you would need to compare a sealed LT and a EBS, then I think EBS would win if the sealed LT is designed to have the same frequency response in room. Distortion would be way lower. The box could be much bigger, of course.

[noah katz]

"It's really hard to really compare ported vs. sealed because they are so different."

Seems to me that makes comparisons a lot easier.

Anyway, GD is always mentioned as the reason ported is inferior, so to test that both should be EQ'd to the same freq resp to eliminate that variable.

Also, for most people the room will be a bigger determinant of bass SQ than the sub (ring times much longer than even a mediocre sub), so anyone who's halfway serious ought to have EQ.

[johninCR]

Originally posted by noah katz

Also, for most people the room will be a bigger determinant of bass SQ than the sub (ring times much longer than even a mediocre sub), so anyone who's halfway serious ought to have EQ.

Bass management processing is just a bandaid that masks the problem somewhat. It doesn't correct the problem. Anyone who's more than halfway serious ought to have physical bass treatments in their room. That why I constructed my room so that 50% of the walls and 100% of the ceiling are panel bass traps tuned to different frequencies and the long side wall of bass traps forms one very low tuned bass trap using the sealed airspace and wall behind that.

Using the rock music that I usually listen to, I think the EBS sub I used, which is tuned to 16hz if I recall correctly, has a pretty comparable response sealed or ported from 40hz up to the 80hz cutoff I use on the HT rig and that music doesn't have much content below that. Just because computer modelling predicts an equal response doesn't mean they sound the same.

[noah katz]

You're correct, room treatments are the place to start.

[BassAwdyO]

John.... one question I have is this, Where is your first port resonance.

EBS enclosures Typically have LONG ports especially if it happens to be a smaller box with a larger driver(which is definately the case for Tumult). The high excursion of the sub only makes it worse because the cross section of the port has to be larger making it even longer for such a low tuning.

When you get a first port resonance at 80hz, even if you cross over at 40hz 24db/octave the port is probably going to muddy things up a bit at 80hz from the port. If you cross higher, the problem gets ALOT worse. As I understand passive radiators negate these effects, one reason why I opted to use them.

[johninCR]

Bass,

I'm not into ported enclosures and built the thing 2 years ago. Going from memory it's 360 litres (maybe 320L) with dual 4" x 17" ports. I think the straight parts are 15" and both ends are flared.

It's not a resonance or room modes. It's the alignment. I really can't believe that you guys really can't hear the difference.

[BassAwdyO]

where are you crossing at dude?

Having extremis midwoofers in my mains puts me down to about 42hz f3 and crossing below that isnt seriously detrimental. The sub's band is very small for music. Either it's not a critical portion of the frequency spectrum, or my ears suck, because I cant tell a difference(except in the intensity of infrasounds)

[noah katz]

" I really can't believe that you guys really can't hear the difference."

You haven't addressed what difference you're referring to.

Of course different FR sounds different.