[J.V. Gomez]

Last night, while picking movies at the local DVD-rental store, one of the owners (a newbie who, because of his interest in getting into HT for his home, takes advantage of any time I stop by to issue his daily questions) shared with me the last "tip" he had gotten from a friend of his (who, suppossedly, is a knowledgeable person in speaker matters and a speaker retailer in a nearby city):


(quoting): "Hey, J.V., Giovanni, the friend I told you about the other day, is offering me one subwoofer for purchase. He told me that this is the best subwoofer money can buy because it has a 6th-order vented cabinet. What order are your subs' cabinets (making reference to my Aerial SW12s)?"


My answer was: "Well, Fabrizio, to tell you the truth, I am not really aware of vented speaker cabinets being classified in terms of the "order" of their cabinets. The only "order" I can think of in relation to subwoofers is the order of their high-pass and low-pass filters, but that is a different story. However, I am not saying that what your friend told you is wrong, it is only that if there is a concept of "order" linked to any aspect of the internal design of vented subs or speakers, I'm not aware of it".


I ended the conversation promising the fellow that I would post the question on AVS, hoping that the issue could be clarified. So, here are the questions:


1) Is there any concept of "order" that can be associated to the design of vented subs/speakers? Is it correct to talk about 4th-order, or 6th-order, or Nth-order-type of vented subs/speakers?


2) If the answer to the question above is affirmative, where to find (ie. web site address) literature on the subject?


3) Again, if the answer were affirmative, how to find out what the "order" for any particular vented sub or speaker is? For instance, how to find out what the order of my Aerial SW12 is?


I hope these are not silly questions.


Thanks for your help, fellows.


J.V.

 

[Brucer]

Here's a good place to start-

www.diysubwoofers.org/bnd/6thorder.htm


Regards, Bruce

 

[JRace]

Not a silly question at all.


There are in fact 'orders' when reffering to a subwoofer enclosure.

A 6th order subwoofer box is a Bandpass box with two ports like this:
http://www.diysubwoofers.org/bnd/6thordbp.gif


Some sites to go to:

www.diysubwoofers.org


Please note: There is no Best box, and infact if built wrong (which is very easy to do) a 6th order bandpass box will sound worse than any other.


Hope this helps

 

[catapult]

Quote:

Please note: There is no Best box, and infact if built wrong (which is very easy to do) a 6th order bandpass box will sound worse than any other.

Amen. Some of the worst "one note bass" subs are 6th order. Just as an FYI, B*se uses 6th order enclosures. Definitely not a case of higher is better when comparing to a quality 4th order vented design like the Aerial.


ps - the whole "order" thing is easy to understand. It's just how fast the bass rolls off below the tuning frequency. 2nd order (sealed) = 12 dB/octave. 4th order (vented) = 24 dB/octave. 6th order (bandpass) = 36 dB/octave.

 

[J.V. Gomez]

Catapult, JRace, and Brucer:


Thanks a lot, fellows for the most interesting info.!!! I am very, very grateful.


That old saying about never going to bed without having learned something new that day, has been fully accomplished thanks to your most appreciated information. I wasn't aware of that for sure.


Best regards, fellows


J.V.

 

[J.V. Gomez]

Catapult:


just one more question (and pardon my ignorance if this is a silly one): in your post, you mentioned that the cabinet of the Aerial SW12 sub is a 4th-order one. Upon visiting www.diysubwoofers.org, I see that the picture to that class of design ( www.diysubwoofers.org/bnd/4thorder.htm ) is not as similar as the external look of my Aerial sub. In turn, the picture for the ported system ( http://www.diysubwoofers.org/prt/ ) seems to better match the geometry of the Aerial.


Is it the SW12 a 4th-order bandpass design or a ported one?


Internal pictures of the SW12 can be seen at:
http://www.aerialacoustics.com/sw12thmb.htm


Thanks for the clarification!


J.V.

 

[Brucer]

J.V - you are correct

 

[catapult]

Right on all counts J.V. The SW12 is a 4th order ported (not bandpass) design. As an aside, it would be really interesting to know what your "expert" at the video store considers superior to the SW12, which is generally considered to be one of the finest subs on the planet.

 

[Brucer]

Maybe he was refering to the B*se, LOL

 

[J.V. Gomez]

Brucer, Catapult:


Thanks again for your clarification.


Regarding the pal at the video store, right now he demoes the DVDs with a set of pretty old Peavey speakers. They sound like hell, if you know what I mean (ie. BOOM!, BOOM! BOOM!), but what the heck, I think the high volume listened from the outside of the store keeps the people coming to the store to see what is going on (an eventually leading to people to rent a couple of movies). So, I think he is not going to be very interested on getting into the Aerials.


Nice chat, fellows!


J.V.