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In Reply to: RE: Bass reflex vs acoustic suspension vs inf. baffle posted by Scott L on September 10, 2016 at 03:31:05
A closed box inherently will exhibit less overhang than a reflex box. That's inherent in the physics of the design. A reflex can be quite good properly designed but not as good. There is no way a reflex speaker can be done to have as little bass overhang as a closed box.
Reflex was hard to design before computers but with a good piece of software and a knowledgeable designer it's not a big deal any more. I've seen it done. I've seen a whole reflex speaker done in half a day with only fine tuning (personal preference) left to do after computer design.
I have woofer boxes that were designed to be used both ways that were well designed by a very good designer and it's obvious that while the reflex design is among the best the closed box is tighter.
Follow Ups:
Well, if you think a sealed box is better, then by all means use one !!
What did I tell the original poster ?
The argument will NEVER end.
Of course the argument will never end especially in audio where everyone is an 'expert' which is true for his own use but that doesn't mean that in some situations there isn't a scientific answer. Extra over hang is not accurate. Liking it is another statement. My friend who designed my woofers prefers the affect of extra overhang probably because of weaknesses in recording but he does know it's distortion.By the way I do understand why my friend preferred the ported version of his woofer. I used it that way for a long time and it has alluring characteristics that I miss from the closed version. But that's taste and not fidelity to the signal.
Edits: 09/10/16 09/10/16
It's audio-folk-lore.
Vented systems actually have much less distortion than sealed systems.
See, I knew this would happen.
What is audio folklore? Why should reflex have less distortion? I need a measurement or better a logical reason. And isn't bass resonance(overhang) a distortion? And that's explainable and measureable.
What, you cannot actually read books to learn?
Buy "Bullock On Boxes" and study it.https://www.google.com/#q="bullock+on+boxes"
Warning, actual college level math is required.
Distortion goes up with excursion.
Reflex has much lower excursion than acoustic suspension (at the same SPL).
This only applies at and above tuning frequency (a woofer suitable for either use goes lower and louder in a bigger BR enclosure, with lower distortion).You might also want to look at horn enclosures, much harder to design and build but have even lower excursion.
Here's a man that does horns 'right':
http://www.prosoundweb.com/article/in_profile_tom_danley_exploring_the_possibilities_of_audio_technology/You'll get more respect if you actually research your own inquiries instead of arguing with people sharing their hard won experience.
FYI: I've built dozens of speakers from 1/4 to 25 cubic foot, I have built acoustic suspension, reflex and horn enclosures. I supported myself through the 80's doing live sound with cabinets I designed and built. Too hard on the body, I had to give it up before I caused my body to break down by moving a ton (literally) of gear several times a week.
It is really cool to see Tom Brennan and Freddy Ireson still posting here.
Jeff Robinson
Edits: 10/20/16 10/20/16 10/20/16
Audio-Folklore is comparable to when three blind men describe an elephant.
As to the operating principles of a bass reflex, or "vented loudspeaker",
I would encourage you to do your own research. I suppose I could easily answer your questions, but that would most likely result in continuing the "argument",
which is what I wanted to avoid in the first place.
Once a person has subscribed to an achieved belief system, evidence to the contrary would be considered invalid.
That's a trust me answer and worth nothing in a discussion. I do know something about low end design which is what my discussion is based on. The quality of closed box bass is better than reflex bass all things being equal. Reflex is used because it's what people are used to, it's more efficient and the drivers available unless custom made are designed to be used in reflex boxes and are not good matches with closed boxes.
Will you two please go get a room.
A closed box is not an infinite baffle. It's a mass-spring system.
And you cannot have a driver which is optimized for both bass reflex and closed box. The fact that one sounded tighter than the other can be attributed to several factors.
Of all the back-and-forth between you two, neither of you has shown even one single MLSSA graph, or gone any further than arguing about Merlot versus Cabernet.
I *get* that closed box doesn't do the "capacitor" thingy that bass reflex does, but the question is: In a well-designed system, can we hear it? If you cross a woofer at, for example, 100 Hz at 24 dB/octave, the "punch" and definition isn't even coming from the woofer. It's coming from the lower midrange driver.
Many years ago, I had the opportunity to learn from loudspeaker designer John Meyer (meyersound.com). He taught me a LOT about loudspeakers. Then, I read Olson's "Music, Physics and Engineering" and Dickason's "Loudspeaker Design Cookbook".
Other than from a purely theoretical perspective, a closed box is not necessarily better than a bass reflex box.
:)
I used vented boxes because the woofers I thought made the best midrange and most realistic vocals were woofers for vented boxes. Midrange trumps bass.
Now theoretically for a given driver size, output and F3 a vented design has less excursion than a sealed one and thus less harmonic and IM distortion. So with neither sealed or vented being perfect the choice of which makes better bass becomes a choice of what kind of distortion one finds more bothersome. A preference, a matter of taste.
In any event the proselytizing for sealed boxes on a HE forum puts me in mind of Jehovah Witnesses knocking on doors. "Don't answer the door, it's those sealed box people again!"
When the volume goes up those sealed boxes go up in distortion fast, easily hearable. That sound really bugs me, some folks might be more immune to it.
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