Reflex vs sealed

[454Casull]

Have there ever been any double-blind listening tests between ported and sealed subs with the same in-room response (at listening position, of course)? Just wondering how many people who prefer sealed subs to ported subs would consistently pick out sealed subs in such a test (low-to-medium SPL to prevent the advantage from going to the ported subs).

[RobWells]

You mention that the ported would have an advantage over sealed at high volumes.. What about if your source material has plenty of output below the 'advantaged' ported subs tuning frequency ?

Rob.

[infinia]

I'd be interested in a test similar to this. but looking specifically at group delay differences between a BR an a AS.

[Cloth Ears]

With suitable source material, it's fairly easy to tell the difference, unless your ported sub is quite a large alignment. Simply, the sealed sub will roll-off at around 12dB/octave, and the ported at around 24dB/octave (vast simplification here!).
Assuming un EQ'd bass (big assumption), the ported will have a flatter frequency response down to it's port tuning frequency and will then fade away quite quickly. The sealed will start rolling off sooner, but extend out more. If you take room 'boost' into account (which may be difficult do to reflection nodes), then you might find your ported sub to sound a lot boomier in the frequecy range between port frequency and where the room reflections start boosting the bass. The sealed, due to it's roll-off at around the same rate as the room boost, may not show this effect.
But, it really depends on the subwoofer and the room. There are many ported subs on the market, due it being quite cheap to get reasonable levels of bass out of a ported box (compared to a sealed one using the same amplification and size). I feel that you get better bass from a sealed than a ported - but that's a personal preference (and I'm talking below 50Hz, here). Others prefer open baffle (but I can't justify the size for a 20-50Hz subby) or bass horn (ditto) or tapped horn (haven't tried).

[454Casull]

Originally posted by RobWells
You mention that the ported would have an advantage over sealed at high volumes.. What about if your source material has plenty of output below the 'advantaged' ported subs tuning frequency ?

Rob.

Designing a ported sub such that its tuning frequency is above that of the lowest frequency required of it is rather disingenuous, wouldn't you say? This isn't supposed to be a test of good design vs bad design. Picking crap does nobody good.

[454Casull]

Originally posted by Cloth Ears

Assuming un EQ'd bass (big assumption), the ported will have a flatter frequency response down to it's port tuning frequency and will then fade away quite quickly. The sealed will start rolling off sooner, but extend out more. If you take room 'boost' into account (which may be difficult do to reflection nodes), then you might find your ported sub to sound a lot boomier in the frequecy range between port frequency and where the room reflections start boosting the bass. The sealed, due to it's roll-off at around the same rate as the room boost, may not show this effect.

Yes, which is why I qualified my post with "with the same in-room response".

[MJL21193]

Originally posted by 454Casull

Just wondering how many people who prefer sealed subs to ported subs would consistently pick out sealed subs in such a test

Not many I'd guess.

[infinia]

Originally posted by MJL21193



Not many I'd guess.

Because there are not many good woofers made for AS any more. i.e. Fs<20 Hz with soft suspension. Apparently they are very hard to make with good QC.

[454Casull]

Originally posted by infinia


Because there are not many good woofers made for AS any more. i.e. Fs<20 Hz with soft suspension. Apparently they are very hard to make with good QC.

Hope on the horizon

http://www.aespeakers.com/drivers.php?driver_id=8

[MJL21193]

Originally posted by infinia


Because there are not many good woofers made for AS any more. i.e. Fs<20 Hz with soft suspension. Apparently they are very hard to make with good QC.

I didn't have any problem finding some. By chance I found 4 relatively new 15" woofers at Goodwill that are perfect for acoustic suspension.
I used two for my workshop speakers: