The way I see it, the amount of air in the high frequencies that a tweeter operates is totally irrelevant.
It is not always isolated in a dedicated compartment, but it is convenient to do so to avoid acoustic interactions, the xover must do the job without extraneous waves.
Faital-3WC
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I can't find a hole in that argument!
Humm, don't believe, my life is always full of holes, in the pockets and of others.
It is compensation.
Right, but I mentioned my observation since changing air pressure issues are what I assumed the holes were put in them for. It was many years ago but I did have a conversation with the guys in the shop where they were for sale and they explained the reason. You could see they were put there with a hot implement.
Okay. It just seems logical that a sealed tweeter, or any other driver in a sealed compartment would be subject to the same issues. I don't remember the brand of speaker I noticed this on, as I mentioned many years ago, but it was made clear, (no pun intended), why the holes were there. I'm by no means qualified to make a judgement.
Peace
Peace
Sealed is Not Acoustic Suspension in Loudspeakers | Audioholics
Here is a good article on the difference between "sealed" and "Acoustic suspension"
The speaker design was AR's "trick".
The casing and the spider were much more elastic than in a conventional speaker of that time, (high compliance) their function was to keep the VC centered, but the return force of the cone was provided by the air enclosed in the cabinet.
I think it deserves a reading and some opinions, it is a good article.
PS: If I remember correctly, TG did not design any "sealed" cabinet, so I must conclude that the final part of the article is correct. Are there currently no speaker manufacturers with the TS features to emulate AR? Why do they believe? The speakers used in subwoofers have great compliance but limited FR....
Power is very cheap these days. What are we missing?
Is this statement shared by the experts here?
" As excursion for bass drivers have grown larger, high compliance suspension of the type needed for acoustic suspension design becomes more difficult to engineer for reliable performance. The thin suspension components needed for high compliance suspension are susceptible to self-destruction at high excursions, not to mention increased distortion from rocking modes and deformation. Furthermore, air doesn't have enough damping force against the effects of progressive suspension for high excursions. At high excursions, the suspension must be able to damp itself, and that means that it has to have lower compliance than an acoustic suspension system would call for. Acoustic suspension was a more viable solution in older eras of loudspeaker design when one-way linear excursion could be around 5mm, but modern designs aim for much larger excursions where high compliance suspensions become impractical. "
Here is a good article on the difference between "sealed" and "Acoustic suspension"
The speaker design was AR's "trick".
The casing and the spider were much more elastic than in a conventional speaker of that time, (high compliance) their function was to keep the VC centered, but the return force of the cone was provided by the air enclosed in the cabinet.
I think it deserves a reading and some opinions, it is a good article.
PS: If I remember correctly, TG did not design any "sealed" cabinet, so I must conclude that the final part of the article is correct. Are there currently no speaker manufacturers with the TS features to emulate AR? Why do they believe? The speakers used in subwoofers have great compliance but limited FR....
Power is very cheap these days. What are we missing?
Is this statement shared by the experts here?
" As excursion for bass drivers have grown larger, high compliance suspension of the type needed for acoustic suspension design becomes more difficult to engineer for reliable performance. The thin suspension components needed for high compliance suspension are susceptible to self-destruction at high excursions, not to mention increased distortion from rocking modes and deformation. Furthermore, air doesn't have enough damping force against the effects of progressive suspension for high excursions. At high excursions, the suspension must be able to damp itself, and that means that it has to have lower compliance than an acoustic suspension system would call for. Acoustic suspension was a more viable solution in older eras of loudspeaker design when one-way linear excursion could be around 5mm, but modern designs aim for much larger excursions where high compliance suspensions become impractical. "
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No difference in principle between "acoustic suspension" and sealed unless that theory about enclosed air heating and cooling behaviour matters. But again, just a matter of degree.
I have an AR-1 that I plug in once in a while. It is an excellent sub although doesn't go as low as people want today which isn't bad for 65 yrs. The cone is very stiff and very heavy. Fs is somewhere down at 14 Hz but in the 1.4 cu ft box, like 35 Hz (just rough memory).
Like a puppy, I'd love to see my old beat up AR-1 find a new home with somebody who'll be nice to it or a museum.
Just how much does a cubic foot (or liter) of air expand with atmospheric changes? Has that been posted?
B.
I have an AR-1 that I plug in once in a while. It is an excellent sub although doesn't go as low as people want today which isn't bad for 65 yrs. The cone is very stiff and very heavy. Fs is somewhere down at 14 Hz but in the 1.4 cu ft box, like 35 Hz (just rough memory).
Like a puppy, I'd love to see my old beat up AR-1 find a new home with somebody who'll be nice to it or a museum.
Just how much does a cubic foot (or liter) of air expand with atmospheric changes? Has that been posted?
B.
Send it to me with all shipping costs paid, here you will find a home full of love.
Thanks for link and Art is a valuable guide again. I don't think that answers the question in a way I misunderstand it. Does that means 68 lbs on cone for .1 inches or what?
I suppose we can ignore temperature changes? Which leaves the barometer and hygrometer?
Should be crucial to know the real numbers, eh.
B.
C'mon, all I (and everybody else on this long thread) want is information that enables us to answer a question like:
if I have a 3 cubic foot cab and a 15-inch driver, how far will the cone be displaced between a typical low atmosphere day and a high day?
(If I knew that, I think I can translate that just fine to my cab and driver and weather - or at least have some bit of perspective on this issue* because at this moment I have zero perspective on this issue.)
B.
* the issue is: do we need some little pin-hole leak in a sealed box?
if I have a 3 cubic foot cab and a 15-inch driver, how far will the cone be displaced between a typical low atmosphere day and a high day?
(If I knew that, I think I can translate that just fine to my cab and driver and weather - or at least have some bit of perspective on this issue* because at this moment I have zero perspective on this issue.)
B.
* the issue is: do we need some little pin-hole leak in a sealed box?
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You could probably calculate it using t/s parameters for the driver in question. Just imagining the function of a barometer suggests that yes, wee need that little hole. This has been considered a factor in speaker performance for a very long time, probably since it's inception.
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"You could probably calculate it using t/s parameters for the driver in question."
Golly Discopete, I am just not smart enough do know how to do that. Would you please do it for all of us. Just pick parameters (or some driver with T/S specs on Parts Express or shared otherwise) you find convenient to work with.
Ultimately, as I said before, all any of us want to know is very roughly how far will a cone move.
Thanks a million.
B.
Golly Discopete, I am just not smart enough do know how to do that. Would you please do it for all of us. Just pick parameters (or some driver with T/S specs on Parts Express or shared otherwise) you find convenient to work with.
Ultimately, as I said before, all any of us want to know is very roughly how far will a cone move.
Thanks a million.
B.
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" Ultimately, as I said before, all any of us want to know is very roughly how far will a cone move."
No, no.
No, the OP (me) gave an example of SL with 50 liters = 1.76 ft3 and wants to know if you were right to use a slightly larger hole diameter.
(1.25mm instead of 1mm) in its own sealed enclosure which is 5.29 ft3 = 150 liters
What about my offering ?
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