Speaker resonance
Speakers do not produce strong sound output below their resonant frequency.
Resonance is the natural frequency of vibration of any mass attached to a spring like restoring force. For any speaker, its lowest resonant frequency is in free air. While in free air, however, the air from the back comes around and cancels the air movement from the front. This is because when the speaker is pushing the air from the front side, it is pulling the air from the back. Even while a speaker in free air may be moving a lots of air, it will not sound very loud. The pulled (low pressure) will cancel the pushed air (high pressure).
The free air resonant frequency depends on the mass of the cone, and the stiffness of parts that support the cone. If you modify the cone support system, you will change its resonance. The stiffer the the support, the higher the resonance. All other things being equal, a speaker with a foam surround will have a lower resonance that a speaker with a rubber surround. This has an advantage for good bass. However, foam breaks down more than rubber with age, and in 20 years you may have to replace the foam.
When a speaker placed in a box, the resonance is increased, because the air behind speaker acts a restoring force which has the same effect as stiffening the surround.
When a large speaker is placed in a small box, it moves more air inside the box than a smaller speaker. This gives the larger speaker the impression that the air in the box is stiffer than what the smaller speaker would experience. The net result is a larger shift in the resonance of the larger speaker, driving the resonance up more.
If a box is too small, the larger speaker is at a disadvantage. Yes, a large speaker will move more air, but not in a box that is so small as to drive its resonance up too much. Net result, its low bass output will suffer more.
Speakers do not produce strong sound output below their resonant frequency.
Resonance is the natural frequency of vibration of any mass attached to a spring like restoring force. For any speaker, its lowest resonant frequency is in free air. While in free air, however, the air from the back comes around and cancels the air movement from the front. This is because when the speaker is pushing the air from the front side, it is pulling the air from the back. Even while a speaker in free air may be moving a lots of air, it will not sound very loud. The pulled (low pressure) will cancel the pushed air (high pressure).
The free air resonant frequency depends on the mass of the cone, and the stiffness of parts that support the cone. If you modify the cone support system, you will change its resonance. The stiffer the the support, the higher the resonance. All other things being equal, a speaker with a foam surround will have a lower resonance that a speaker with a rubber surround. This has an advantage for good bass. However, foam breaks down more than rubber with age, and in 20 years you may have to replace the foam.
When a speaker placed in a box, the resonance is increased, because the air behind speaker acts a restoring force which has the same effect as stiffening the surround.
When a large speaker is placed in a small box, it moves more air inside the box than a smaller speaker. This gives the larger speaker the impression that the air in the box is stiffer than what the smaller speaker would experience. The net result is a larger shift in the resonance of the larger speaker, driving the resonance up more.
If a box is too small, the larger speaker is at a disadvantage. Yes, a large speaker will move more air, but not in a box that is so small as to drive its resonance up too much. Net result, its low bass output will suffer more.
Please be honest, can a 10 inch woofer offer the same impact of bass, I'm telling of the first octave 20-40Hz of a 15 inch?
I;m asking this because of the quote of a JBL guy, MArk Gunder: "to make sound, you must move air"
I hope this is not what you are telling your wife ....
Too vague of a question. It's like asking: can a truck go faster than a sportscar?
Some sportscar to be beaten by a truck ...
Hi,
A really good 10" will slaughter a poor 15", it just needs around double
the xmax to do the job the same. Given your talking 20Hz to 40Hz, that
is possible in moderate volume with a lot of power with a 10". Generally
speaking a poor 15" will need a lot more box volume and less power.
However, if the 15" has about 4 times the cone mass of the 10" and
the same xmax, it will slaughter the 10", but will need a far bigger
magnet to do so, and will be commensurately much more expensive.
A good 15" will kill a good 10", depending on your design criteria.
Which it all boils down to, good design, and proper drivers for purpose.
rgds, sreten.
Agree , SPL ONLY , As Long excursion , means more distortion , when the woofer has to come from waaaaayyyy out there for the next bass note ...
What became of the 30" from Fostex. I saw them in the 80s?
Two of those would make a nice sub.
In the 70's i had EV 30inchers and Hartley 24inch monsters , stupidly , I gave them away ...
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........is like saying a 4 cylinder engine is better than an 8 cylinder engine.
for fishing boats they have preferred 3 cylinders for being less hard on the wood construction
Ugh !! Like covering a steak with crushed Oreos and sprinkling vanilla over it.lamb au sweet wine
Marinate your lamb overnight in *dry red* wine and spices before cooking and *then* maybe we'll agree.
Back to the speaker choice, *if* you are limited by size (as in designing a speaker system for a typical Living Room) a 10" speaker can easily outperform a 15" speaker, hands down.
As in way flatter response, deeper bass, smooth sound, and so on.
It will need more driving power, of course, piece of cake.
Now, if we talk live sound, such as Band PA or DJ stuff , and have no size/weight/power limitations and want highest SPL, yes, 15" are preferred over 10".
But to make a choice, the OP question must be rephrased in more precise terms.
As is, it's too vague.
ok, lets take a normal 88db 10" bass/sub woofer
put in in a closed box where it rolls off at 35hz, giving -6db at 30hz
then put a 96db 15" in a closed box where it rolls off at 50hz, giving -12db at 40hz
so if you remove anything above 50hz, SPL at low frequencies could be equal for both woofers, in theory
will it happen that way in reality ? .......don't know
but man, when I look at a hifi woofer, and visually compare it to a PRO woofer, many hifi woofers look like crap
put in in a closed box where it rolls off at 35hz, giving -6db at 30hz
then put a 96db 15" in a closed box where it rolls off at 50hz, giving -12db at 40hz
so if you remove anything above 50hz, SPL at low frequencies could be equal for both woofers, in theory
will it happen that way in reality ? .......don't know
but man, when I look at a hifi woofer, and visually compare it to a PRO woofer, many hifi woofers look like crap
Back to the speaker choice, *if* you are limited by size (as in designing a speaker system for a typical Living Room) a 10" speaker can easily outperform a 15" speaker, hands down.
I'll take you up on that, try beat these, they'll blow your back wall out if they're not brick and mortar
EDIT: I was answering to tinnitus
Agree and add:
Back to the question: "if you remove" ... (you'd need a steep and expensive crossover for that) they may *measure* the same SPL with a sinewave, but won't sound the same with any program you send there.
Basically the 15" in a too small cabinet will sound "dry" while the 10" in a cabinet where it feels comfortable will sound "smooth".
Hope the words explain the sound.
But anyway "listening with your eyes" is for noobs and the untrained, isn't it?
EDIT: now answering to balerit bragging
As of the sound, it will be incredibly uneven, with a strong 200Hz bump, no real deep bass, honking shrill treble and no real high end either.
Typical "horn sound".
Mind you, I respect Altec Lansing A7, have built a ton of them (long ago), and they were state of the art ... in 1935 .
I *have* mixed records in Pro Studios which used them as monitors, in the late 60's.
By '75 nobody used them any more.
Maybe there was some reason for that
Since you seem to be a Horn man (fine with me) I suggest you add some good bullet tweeters to hear something above 10 KHz, and a couple man sized Bass horns (starting about 8X the cabinet volume you have now) to have something below 100 Hz.
Personally I'll keep my Hi Fi type all-cone speaker (ok, it includes a silk dome tweeter).
Altec Lansing A7 were needed when you had to fill a 1600 seat Cinema Theater with a 30W tube amplifier; nowadays SS watts are cheap and plentiful.
PS: congratulations, beautiful cabinet work.
post.ok, lets take a normal 88db 10" bass/sub woofer
Agree and add:
Well, that's cheating, because the box which will allow the 15" speaker do so, will be, say, 20X the volume of the other one, so, the example is not valid.ok, lets take a normal 88db 10" bass/sub woofer
put in in a closed box where it rolls off at 35hz, giving -6db at 30hz
then put a 96db 15" in a closed box where it rolls off at 50hz, giving -12db at 40hz
Well, I know, because I have tested *many* speaker/cabinet combinations; I commercially make Bass amps and cabinets so for me it's a very real problem to solve.so if you remove anything above 50hz, SPL at low frequencies could be equal for both woofers, in theory
will it happen that way in reality ? .......don't know
Back to the question: "if you remove" ... (you'd need a steep and expensive crossover for that) they may *measure* the same SPL with a sinewave, but won't sound the same with any program you send there.
Basically the 15" in a too small cabinet will sound "dry" while the 10" in a cabinet where it feels comfortable will sound "smooth".
Hope the words explain the sound.
That's a personal visual preference, can't argue about that, I often see it the other way.but man, when I look at a hifi woofer, and visually compare it to a PRO woofer, many hifi woofers look like crap
But anyway "listening with your eyes" is for noobs and the untrained, isn't it?
EDIT: now answering to balerit bragging
Well, if the objective is blowing brick and mortar (which they really aren't capable of doing, of course) yes, I agree they will achieve a higher SPL.try beat these, they'll blow your back wall out if they're not brick and mortar
As of the sound, it will be incredibly uneven, with a strong 200Hz bump, no real deep bass, honking shrill treble and no real high end either.
Typical "horn sound".
Mind you, I respect Altec Lansing A7, have built a ton of them (long ago), and they were state of the art ... in 1935 .
I *have* mixed records in Pro Studios which used them as monitors, in the late 60's.
By '75 nobody used them any more.
Maybe there was some reason for that
Since you seem to be a Horn man (fine with me) I suggest you add some good bullet tweeters to hear something above 10 KHz, and a couple man sized Bass horns (starting about 8X the cabinet volume you have now) to have something below 100 Hz.
Personally I'll keep my Hi Fi type all-cone speaker (ok, it includes a silk dome tweeter).
Altec Lansing A7 were needed when you had to fill a 1600 seat Cinema Theater with a 30W tube amplifier; nowadays SS watts are cheap and plentiful.
PS: congratulations, beautiful cabinet work.
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I'll take you up on that, try beat these, they'll blow your back wall out if they're not brick and mortar
Lol, or blow out your backwall if it's made from tar and paper ....
Ugh !! Like covering a steak with crushed Oreos and sprinkling vanilla over it.
Marinate your lamb overnight in *dry red* wine and spices before cooking and *then* maybe we'll agree.
Back to the speaker choice, *if* you are limited by size (as in designing a speaker system for a typical Living Room) a 10" speaker can easily outperform a 15" speaker, hands down.
As in way flatter response, deeper bass, smooth sound, and so on.
It will need more driving power, of course, piece of cake.
Now, if we talk live sound, such as Band PA or DJ stuff , and have no size/weight/power limitations and want highest SPL, yes, 15" are preferred over 10".
But to make a choice, the OP question must be rephrased in more precise terms.
As is, it's too vague.
Dear Hermano, if you someday come to Fortaleza, Brasil, I will go with you to show you how delicious is this lamb It a young lamb, here we call `cordeiro mamão` so the meat is very soft.
By the way, I love Buenos Aires, there I eaten the best Bife Chorizo in my holy life at "El Cabrera"!!! I pretend to go back when there is a good musical show, like U2 or other rock band, if you should know some concert please let me know.
Gracias.
EDIT: I was answering to tinnitus
post.
Agree and add:
Well, that's cheating, because the box which will allow the 15" speaker do so, will be, say, 20X the volume of the other one, so, the example is not valid.
isn't that a bit over the top ? ...2x volume would do it, and be quite fair I would say
Back to the question: "if you remove" ... (you'd need a steep and expensive crossover for that).....
one more .... I will have to choose my words more carefully in the future ...I would never use higher than 24db for a sub filter
But anyway "listening with your eyes" is for noobs and the untrained, isn't it?
I hope this don't mean you take me for an idiot ....
no, I really think quality hifi drivers are overpriced
and technology is...just average, mostly
Try to beat this 10" and don't ask silly questions. (And) Prove it!5) so with a quality 15 inch, a good enclosure and a good power, there is no way a 10 inch can beat.
Note: this in someway relates to "what's the best loudspeaker driver" question that many ask... good question, there's always a better one/application.
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Just do the Math, it will clear many doubts.isn't that a bit over the top ? ...2x volume would do it, and be quite fair I would say
try beat these
OK, nice satellites, but why no pictures of the woofers?
Attachments
Thanks, I'll remember your invitation.Dear Hermano, if you someday come to Fortaleza, Brasil, I will go with you to show you how delicious is this lamb It a young lamb, here we call `cordeiro mamão` so the meat is very soft.
By the way, I love Buenos Aires, there I eaten the best Bife Chorizo in my holy life at "El Cabrera"!!! I pretend to go back when there is a good musical show, like U2 or other rock band, if you should know some concert please let me know.
Gracias.
Obrigado, vou lembrar seu convite
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