Vented Sub People: How Would You Defend These Statements? (1 Viewer)

[Chuck C]

I was reading an old edition of Widescreen Review, and here's what the editor had to say

A good, sealed enclosure subwoofer is preferred for critical music listening...Vented or bass reflex powered subwoofers can play louder and can produce thunderous bass output, but they are deficient at reproducing music's rhythm and pace...If you want a subwoofer to play at loud 120dB levels, invest in a vented or bass reflex subwoofer, but don't expect such designs to blend as well with your "full-range" loudspeakers or to sound as good.

So does that pretty much sum it up? (SVS, I'm looking in your direction)

 

[Sean M]

That is simply the biased reply of one individual, who happens to write for WSR, making sweeping generalizations about subs. Vented vs. Sealed makes little difference, it depends on how well the design is implemented. TV should be along shortly to explain the why's and wherefor's, but that's really what it boils down to.

 

[John Doran]

sean,
i think tat's a little too pat an answer - it's not that simple. none of the controversies in HT and music audio are.
the position taken by the editor of WSR is more than capable of serious defense; it may in the end not be the best position in that it may not be the position best supported on the balance of the evidence. but that doesn't make it capable of being dismissed out of hand.
- jd

 

[Michael R Price]

Maybe that the loss in bass quality going to a good vented sub is much smaller than some people say, and that the advantages of vented subs (depth, output, less distortion) far outweigh that quality loss?

 

[Greg_R]

I would suggest that this is a generalization about high-Q (high group delay) vented sub designs. It is possible to create a ported design that will have a low group delay and perform very well with music (as well as HT). Many commercial vented designs are underported as well (leading to lots of port noise). A properly designed vented enclosure shouldn't have this problem.

All things being equal, sealed designs (1st order) have a smoother rolloff vs. vented designs (4th order). I believe the numbers are 6dB/oct and 24dB/oct, respectively. The rate of roll off has absolutely nothing to do with integration with your mains. When the roll off occurs at

 

[Paul Clarke]

I tend to agree with the Editor. It may well be at the time of the statement there was, in the mind of the editor, a dearth of quality ported designs.

And it seems there will always be a differentiation between the prime needs and characteristics of HT and those of Music.

Oh well, time for another round of lively discussion.

 

[Dustin B]

Greg nailed it. Most commercial vented subs are tuned very high, are too small and are underported. Comparing that to a low Q sealed design is bound to lead to that conclusion. A larger vented sub, with sufficient volume and porting tuned to 20hz or below will compete very favorably with low Q sealed designs.

As is evidenced by SVS, Adire and a few others that are much more expensive. But saddly they are the exception, which is what probably lead to that editors remarks.

With DIY subs though, they aren't the exception. There are large numbers of awesome DIY vented subs in existence.

 

[Dustin B]

In response to Paul, I'll quote my reply to this discussion from another thread:

In my opinion a sub can either be excellent for both or excellent for niether. If it is an excellent home theater sub it will also be an excellent music sub. If it is an excellent music sub it will also be an excellent home theater sub. Both require a low Q design, good group delay, and a flat freqeuncy response down to 20hz or below at high output with low distortion. And as Thomas mentioned, that all means nothing if it isn't placed and calibrated properly, your room has the biggest effect on a subs sound. But the reverse is also true, no matter how well you place a poorly designed sub, it will still sound bad.

If a sub lacks low end and high output capabilities but has a low Q design and good group delay it will make an acceptable sub for most music, not an excellent one. But it won't make a good home theater sub for action movies.

If a sub has a high Q design and poor group delay numbers, but has the low end and high output it will make a barely acceptable home theater sub, not a good one, and far from an excellent one.

How subs work is quit well understood. It is not that hard to design an excellent sub once you have a good driver (I don't know if a good driver is easy to design or not, my guess is it isn't). Most manufactures make compromises to meet size and cost restriction. Which ones they make will dictate which of the later two categories their sub falls into. Very few manufactures make excellent subs that can fit into the first category. Most of SVS's line does, and compared to the price of the others that do, they are an extreme bargain.

 

[Brian Bunge]

The only thing I would like to clarify is that a sealed enclosure's natural rolloff is 2nd order (12dB/octave) not 1st order (6dB/octave). Otherwise, the sealed vs. vented statement is pretty much an over simplification/generalization as everyone has pretty much said. With proper design, a ported sub can be of very high quality as well.

Also, the highly regarded Aerial SW12 (retail around $4K?) is considered to be underported ("only" 4" flared port) for most diehard DIY'er's tastes. It just goes to show you the types of compromises manufacturers have to make for a retail product. Hell, even the $25K Krell MRS sub can be outdone for around $2K-$3K by a DIY'er!

Brian

 

[Norman Short]

I've been considering posting on this topic myself, ever since I subscribed to Richard Hardesty's AudioPerfectionist Journal. He repeats what he said for Widescreen Review about sealed vs. ported subs. I've been planning to write to him about this controversy myself. SVS claims a Q of between .5 and .6, which should fit his bill at least in part in regards to tight sound for music. But I admit his opinions gave me pause while I've been considering sub choices. I thought maybe I should DIY a large sealed design and see if I couldn't get the best of both worlds. Of course Hardesty looks down on very large cabinets as well; I don't know what he'd say about whether you can sufficiently brace one.

In the end though, I decided that even if I lost a fraction of quality for music (and from what I've heard I might not lose anything at all) that I also needed the high output and very deep bass of home theater, and that I really didn't need a 480L cabinet to get it. I decided on SVS despite his advice. Hopefully someone can get him to listen to one and see if it changes his viewpoint.

Norman Short

 

[Paul Clarke]

Hello Dustin,

Yes, I remember the post from the original thread. I profess my ignorance on acoustical engineering/design up front. My only point (subjective, of course) is that while the design parameters and mathematics behind the construction of any effective speaker, no less subwoofers, may be well known, the finished product and the listening experience drawn from it is no guarantee of any particular excellence. It is the context of sound reproduction which makes for the 'musical vs? HT' distinctions IMO. They do seem to exist...even if only in my imagination.

I am sure that the SVS subs are representative of well balanced subwoofers. If the wife hadn't passed on the shape, I very likely would have one now or be planning to purchase. As it is I decided to stay small.

 

[Tom Vodhanel]

There's little reason to argue someone's opinion....esp Reber's...

TV

 

[Dustin B]

It is the context of sound reproduction which makes for the 'musical vs? HT' distinctions IMO. They do seem to exist...even if only in my imagination

I love it

 

[John Doran]

who's Reber?

(in tom's post, above...)

 

[Norman Short]

Gary Reber is the chief editor of Widescreen Review. His audio editor used to be Richard Hardesty, who formed many of the official stances on equipment, in particular favoring accuracy and time/phase aligned speakers. Since Hardesty left to work on his own AudioPerfectionist Journal, he has been harshly critical of Reber, accusing him (pretty convincingly too from the evidence) of plagiarizing his work and including it in Widescreen Review after Hardesty was no longer with the magazine. He also had sharp criticism of his choices in speaker placement and the heavily damped and processed reference theater the magazine built.

It was Hardesty that first got Widescreen Review to take the stance on sealed over ported subs, though it's certainly possible they would have taken that stance anyway.

 

[Mario_C]

The positions of Richard Hardesty are supported by two highly respected speaker manufacturers. Vandersteen and Dunlavy both say that low Q sealed subs are a must for high fidelity music reproduction. These two speaker manufacturers built high fidlity seakers. There philosophy is quality over quantity.
The thing that must be understood is that no one is saying that vented subs are not good for music. There are a lot of vented subs that are good for both HT and Music. These people are sying that if you want the best sub for music a sealed low Q sub is necessary.
By the way Reber is the plublisher and editor-in-chief of Widescreen Review.

 

[John Doran]

thanks, guys. if i'd been a little more on the ball, i would have figured that one out for myself...

hardesty also likes thiel (another time-and-phase accurate speaker), who is coming out with a subwoofer offering (the sw1), which i can only assume will also be sealed-and-low-Q.

speaking of time-and-phase accurate speakers, has anyone heard meadowlark speakers?

- jd

 

[Brian Bunge]

John,

Meadowlarks are my absolute favorite speakers! I fell in love with the Herons a few years ago and the Nightingales are absolutely huge (300 lbs. each)! My local dealer recently dedicated individual Plinius amps to each L/R speaker!

My dealer has been Meadowlark's top dealer several years running so I've had quite a bit of time listening to most of their offerings. He was the first dealer in the US to stock their entire line.

Brian

 

[John Doran]

brian,

they certainly look good.

do you know how they compare to thiels?

i wish i had the money for either the nightingale or the cs7.2...

- jd

 

[Brian Bunge]

John,

I do specifically remember that my dealer told me he had a customer trade in a pair of Thiels (don't know the model but they retailed for around $7K-$8K two years ago) for a pair of Herons that were $4K back then. I've never actually heard any Thiel speakers myself.

Brian