Time for some fuel on the fire..Getting back a bit to the car Vs. peaker theories and my more basic psyhics ideas I have a few thoughts.. ( duck for incomming fire)
Heres a few thoughts on car Vs. speakers..
I have the privelege of owning a 73 mustang Mach one vert' with a 300HP 7.5ltr 460Ci motor from a motor home, and a 300HP 135Ci 2.2 ltr dodge omni .
Both have around 300HP. one weighs in excess of 4,000lbs the other under 2,500. One makes 500+ Ft/lbs and one makes about 280Ft/lbs . So as was said earlier since they both make 300HP they should both be just as fast. I can assure you this is not so.
While the omni feels a bit peppier, the mustang would trounce the poor omni in anything over a 0-20 foot race.
Also while moving (say 60mph) the mustang would just destroy the omni if pressed into action.
Well if you put the 2.2 ltr in the 4,000 lb frame and the 7.5ltr in the 2,500lb frame the results would get worse.
Heres a thought on HP and torque. would you rather get hit by a 2g BB going mach 1 or a 15Lb bowling ball going 60. Both with the same energy on paper.. which would hurt worse.. which would knock you flat. and which would leave a bigger hole, if say shot at a solid wall.
Torque in the long run is a function is displacment/ability to move air( ability to move air sound familiar? ) . Its work. and power.. HP is a function of power over time. HP is actually a made up number!!!. and its made from torque. [ which is a function of ability to move air ( not accounts forced induction so lets not go there right now)]
So if both are spun at there most effiecent RPM ( maybee say an FS?) they also make peak torque at that RPM, whos going to be making the most HP at that RPM?
I mean HP is torque at 5252 right.. one engine (7.5) makes ALOT of torque ( ie:work) slower than the other engine ( 2.2) that makes less work ( torque) but does it faster( this is why HP always goes higher than torque at 5252rpm ,and torque is higher than HP below that.
One engine is making ALOT of work( the big one) slower than the smaller engine. The other is making less work(torque) but faster.
This is how you can get into the BB Vs. bowling ball idea. ALOT of work slow. or not much work fast.
Well HP and torque is also basically made( besides getting into chamber preasure) from moving air ( dont speakers do that tooo?)
To make 300HP you need X amount of air. The big motor makes 300 HP by moving the same amount of air as the 2.2 motor takes to make the 300HP. But the 7.5 Ltr motor has to do less work( work meaning HP, meaning RPM) than the 2.2 Ltr.The 2.2 Ltr has to spin more( faster) to make 300HP ( that is torque over time).
Basically since one motor has a displacment of 7.5ltrs of air and the other motor is 2.2 ltr, to move the air required to make 300HP ( work over TIME) the smaller motor has to spin faster(time) to do the same amount of work.
well WTF does this have to do with speakers..
isn't making sound just a function of moving(vibrating) air.
to make SPL@frequency wont both speakers( with the same db/wt) have to move the same about of air. wouldnt the larger speaker have to move less( less work) than a smaller speaker to move the same amount of air( make the same SPL).i know bigger motors( car and speaker) take more energy to move and you sacrifice some effiencieny to do it. thats true. the 2.2 uses alot less fuel to make 300HP.
Also if i look at speaker excursion plots I see that a speakers have to move ALOT of air to reproduce low frequency's.so wouldn't a say 15 inch speaker making 100 DB at 20Hz not have to do as much "work"( excusion/wattage) as a say 10 inch speaker doing the same thing. It gets to a point that you start having to move a speaker over an inch to make any sound ( like spinning a engine REALLLY fast.Wouldn't a larger speaker(both having reasonable parameters) be capable of alot more work( moving air) than a smaller speaker.
Isn't a fequency at a DB just like HP ove time.Making a sound at a certain preasure is the same as making torque over a certain time(HP).
i mean a 10 inch speaker trying to make 100DB at say 25hz( lets say 100BD at 25hz = 300 HP) would be like putting my 2.2 ltr in my 4,000Lb plus car. Where a 15 inch speaker making the same sound( lets just say HP) would be like me putting my 7.5 in a omni. Both are doing the same thing ,100Db at 25Hz.. which is more capable. which is actually doing more work. one is just moving further to move the same amount of air to make the same SPL/hz(ie:more RPM?!?!?!?!).
i mean making 25hz at 100 spl is just a measure of Hp, work/time..
you can make a 1 inch sub woofer do 25hz/100spl. it would just have to move back at forth about 2 foot( ie spin faster) or you can make a 30 inch sub do the same thing a move 1mm.
so.. do you want a bowling ball at 60 or a BB at mach 1...
displacement/torque(power)/rpm/hp
speakersize/requency(air molecules moved)/Xmax(conemovement)/25hz @5252
so you want a small motor spinning really fast.
and a smaller speaker moving further.
or a BIG motor puttering along.
and a huge sub not puttering along.
Both can do the same work (300HP)(25hz @ spl)
but you know which one is more effecient at it..
You know F1 engines make around 900HP at 18,000RPM out of a 2.8-3.5ltr engine( I'm interchanging F1/cart here). Or you can get a 2,200 inch motor making 700HP(and 3,800Ft/lbs) at 1,900RPM in generators. Both are making the same HP[torque/RPM(Hz/SPL)].
okay wow.. thats enough amber bock's for the night. its 3:10AM.I'm tipsy and tired. Let the flaming begin.
Good reading so far.
Heres a few thoughts on car Vs. speakers..
I have the privelege of owning a 73 mustang Mach one vert' with a 300HP 7.5ltr 460Ci motor from a motor home, and a 300HP 135Ci 2.2 ltr dodge omni .
Both have around 300HP. one weighs in excess of 4,000lbs the other under 2,500. One makes 500+ Ft/lbs and one makes about 280Ft/lbs . So as was said earlier since they both make 300HP they should both be just as fast. I can assure you this is not so.
While the omni feels a bit peppier, the mustang would trounce the poor omni in anything over a 0-20 foot race.
Also while moving (say 60mph) the mustang would just destroy the omni if pressed into action.
Well if you put the 2.2 ltr in the 4,000 lb frame and the 7.5ltr in the 2,500lb frame the results would get worse.
Heres a thought on HP and torque. would you rather get hit by a 2g BB going mach 1 or a 15Lb bowling ball going 60. Both with the same energy on paper.. which would hurt worse.. which would knock you flat. and which would leave a bigger hole, if say shot at a solid wall.
Torque in the long run is a function is displacment/ability to move air( ability to move air sound familiar? ) . Its work. and power.. HP is a function of power over time. HP is actually a made up number!!!. and its made from torque. [ which is a function of ability to move air ( not accounts forced induction so lets not go there right now)]
So if both are spun at there most effiecent RPM ( maybee say an FS?) they also make peak torque at that RPM, whos going to be making the most HP at that RPM?
I mean HP is torque at 5252 right.. one engine (7.5) makes ALOT of torque ( ie:work) slower than the other engine ( 2.2) that makes less work ( torque) but does it faster( this is why HP always goes higher than torque at 5252rpm ,and torque is higher than HP below that.
One engine is making ALOT of work( the big one) slower than the smaller engine. The other is making less work(torque) but faster.
This is how you can get into the BB Vs. bowling ball idea. ALOT of work slow. or not much work fast.
Well HP and torque is also basically made( besides getting into chamber preasure) from moving air ( dont speakers do that tooo?)
To make 300HP you need X amount of air. The big motor makes 300 HP by moving the same amount of air as the 2.2 motor takes to make the 300HP. But the 7.5 Ltr motor has to do less work( work meaning HP, meaning RPM) than the 2.2 Ltr.The 2.2 Ltr has to spin more( faster) to make 300HP ( that is torque over time).
Basically since one motor has a displacment of 7.5ltrs of air and the other motor is 2.2 ltr, to move the air required to make 300HP ( work over TIME) the smaller motor has to spin faster(time) to do the same amount of work.
well WTF does this have to do with speakers..
isn't making sound just a function of moving(vibrating) air.
to make SPL@frequency wont both speakers( with the same db/wt) have to move the same about of air. wouldnt the larger speaker have to move less( less work) than a smaller speaker to move the same amount of air( make the same SPL).i know bigger motors( car and speaker) take more energy to move and you sacrifice some effiencieny to do it. thats true. the 2.2 uses alot less fuel to make 300HP.
Also if i look at speaker excursion plots I see that a speakers have to move ALOT of air to reproduce low frequency's.so wouldn't a say 15 inch speaker making 100 DB at 20Hz not have to do as much "work"( excusion/wattage) as a say 10 inch speaker doing the same thing. It gets to a point that you start having to move a speaker over an inch to make any sound ( like spinning a engine REALLLY fast.Wouldn't a larger speaker(both having reasonable parameters) be capable of alot more work( moving air) than a smaller speaker.
Isn't a fequency at a DB just like HP ove time.Making a sound at a certain preasure is the same as making torque over a certain time(HP).
i mean a 10 inch speaker trying to make 100DB at say 25hz( lets say 100BD at 25hz = 300 HP) would be like putting my 2.2 ltr in my 4,000Lb plus car. Where a 15 inch speaker making the same sound( lets just say HP) would be like me putting my 7.5 in a omni. Both are doing the same thing ,100Db at 25Hz.. which is more capable. which is actually doing more work. one is just moving further to move the same amount of air to make the same SPL/hz(ie:more RPM?!?!?!?!).
i mean making 25hz at 100 spl is just a measure of Hp, work/time..
you can make a 1 inch sub woofer do 25hz/100spl. it would just have to move back at forth about 2 foot( ie spin faster) or you can make a 30 inch sub do the same thing a move 1mm.
so.. do you want a bowling ball at 60 or a BB at mach 1...
displacement/torque(power)/rpm/hp
speakersize/requency(air molecules moved)/Xmax(conemovement)/25hz @5252
so you want a small motor spinning really fast.
and a smaller speaker moving further.
or a BIG motor puttering along.
and a huge sub not puttering along.
Both can do the same work (300HP)(25hz @ spl)
but you know which one is more effecient at it..
You know F1 engines make around 900HP at 18,000RPM out of a 2.8-3.5ltr engine( I'm interchanging F1/cart here). Or you can get a 2,200 inch motor making 700HP(and 3,800Ft/lbs) at 1,900RPM in generators. Both are making the same HP[torque/RPM(Hz/SPL)].
okay wow.. thats enough amber bock's for the night. its 3:10AM.I'm tipsy and tired. Let the flaming begin.
Good reading so far.
To answer the original question, because most ordinary people are satisfied with 8" to 10" subs; the fanatics with 12" subs, and only the criminally insane or very rich or both can afford or want anything bigger.
And when the criminally insane sit down and work out the details they realize that a multiple of 12" drivers can move as much or more air as the same money spent on 18" drivers, with better power handling, and similar box volume and efficiency. Or they horn-load a single 12" (like the LAB sub).
Some other big drivers that haven't been mentioned yet in this thread:
Hartley 24" (no longer made? and was likely over-rated anyway)
JBL 2241H
Gauss 4883
-both dual-spider pro 18" with good excursion, and capable of bass below 40 Hz in a vented box.
McCauley 6174 and 6256 look very impressive.
And when the criminally insane sit down and work out the details they realize that a multiple of 12" drivers can move as much or more air as the same money spent on 18" drivers, with better power handling, and similar box volume and efficiency. Or they horn-load a single 12" (like the LAB sub).
Some other big drivers that haven't been mentioned yet in this thread:
Hartley 24" (no longer made? and was likely over-rated anyway)
JBL 2241H
Gauss 4883
-both dual-spider pro 18" with good excursion, and capable of bass below 40 Hz in a vented box.
McCauley 6174 and 6256 look very impressive.
Ordinary people dont know what they need so they buy something the salesman tells them they would be happy with, whether its 5" or 8 or 10.
FANATICS!! Welcome to diyaudio.com where subbass doesnt start 'til 12"(clean and loud anyway).
I hope you are joking about this, either that or you know nothing about reproducing low frequencies. BTW a modest 18" can outperform an expensive 12" for about the same price - give or take😀
Oops, someone didnt read the ~20 prior pages of this post. If you dont understand the benefit of Sd then you might want to go easy here, especially w/ the "insane" bit.
Just because they are loud does not mean they are good, not everyone likes horns. Also I believe horns are big and expensive to make!
ABSOLUTELY NOTHING!!!!!!!!!!!!!!!
Please take a hint from AndrewT and tinitus and read the older threads of this post, maybe you'll see how irrelevant hp and torque are.
"Slower"
Whether dipole, sealed, vented or waveguide, woofer diameter has no relationship to "speed". Transducer parameters predict small signal response shape and the shape is the shape no matter the size of the device. If the transducer is willing, EQ can give you any response shape you'd like. Larger size does predict polar response but a 15" woofer "can" get up to 1500Hz (and beyond) quite nicely so a 30" should get to ~800Hz if designed properly.
The concept of speed was (still is) an offshoot of the reality that lightweight cones (everything else being equal) produce more output above their piston range (in their modal region). But F=ma so a=F/m and less m is good for efficiency and more F is also good for efficiency. ESLs have low moving mass, but not because they're better high fidelity drivers, but because they have so little F behind them that they'd be nearly worthless if they had even reasonable mass. Then too, ESLs have predictable and quite unwanted modal behaviors due mostly to their lightweight flat flexible diaphragms.
A solid half sphere of diamond (not lightweight no matter its size) would make a wonderful and nearly perfect diaphragm if you had enough Force behind it. Designers make lightweight diaphragms more for this practical reason (reduce the force needed to drive it to save money) than for the idea of "speed".
A lightweight coned 30" woofer can be far "faster" (better HF response) than an extremely heavy coned 500w aftermarket car audio 10" woofer made to be used in a 40Hz 10L sealed box. But I agree with the earlier post that larger Sd always means larger Vas and therefore larger required box volume and 99.9% of the market will not buy a refrigerator sized box, much less two of them.
I'm a dipole lover so bring on the 30" 100w, Qts of 0.5, Fs of 15Hz and Xmax of 15mm woofer....maybe for $75! But alas, few makers go above 15" and those are meant for boxes.
Whether dipole, sealed, vented or waveguide, woofer diameter has no relationship to "speed". Transducer parameters predict small signal response shape and the shape is the shape no matter the size of the device. If the transducer is willing, EQ can give you any response shape you'd like. Larger size does predict polar response but a 15" woofer "can" get up to 1500Hz (and beyond) quite nicely so a 30" should get to ~800Hz if designed properly.
The concept of speed was (still is) an offshoot of the reality that lightweight cones (everything else being equal) produce more output above their piston range (in their modal region). But F=ma so a=F/m and less m is good for efficiency and more F is also good for efficiency. ESLs have low moving mass, but not because they're better high fidelity drivers, but because they have so little F behind them that they'd be nearly worthless if they had even reasonable mass. Then too, ESLs have predictable and quite unwanted modal behaviors due mostly to their lightweight flat flexible diaphragms.
A solid half sphere of diamond (not lightweight no matter its size) would make a wonderful and nearly perfect diaphragm if you had enough Force behind it. Designers make lightweight diaphragms more for this practical reason (reduce the force needed to drive it to save money) than for the idea of "speed".
A lightweight coned 30" woofer can be far "faster" (better HF response) than an extremely heavy coned 500w aftermarket car audio 10" woofer made to be used in a 40Hz 10L sealed box. But I agree with the earlier post that larger Sd always means larger Vas and therefore larger required box volume and 99.9% of the market will not buy a refrigerator sized box, much less two of them.
I'm a dipole lover so bring on the 30" 100w, Qts of 0.5, Fs of 15Hz and Xmax of 15mm woofer....maybe for $75! But alas, few makers go above 15" and those are meant for boxes.
nunayafb said:
It's Sd and Xmax together that move air. Is there an 18" that'll sweep the same air volume as a Shiva, and achieve a similar F3 for the same price or less? Than a Tempest (OK, that's a 15", but...)?
"Criminally insane" is just a joke. But I suspect that's a thought that crosses my next-door neighbour's mind on occasion, possibly because I have two NHT1259 subs and two DIY Contrabasses.
well, my 18" sweeps 2.25 times more volume, (8.4mm xmax) and has a lower f3 than the shiva, is 6dB louder than the shiva and costs $180-250, cant remember. It does need massive enclosures though to do all of this.
I have nothing against stacking many smaller drivers, I just prefer one big one. I'' take large sd over high excursion any day.
My bad, you sounded serious, so many on this post seem to really hate large woofers.
One of the best realisticaly priced sub's I've heard uses a little 8" servo controlled driver; Akurate 221 from Linn
www.linn.co.uk
www.linn.co.uk
Hi Nun & Mast,
I have read the thread and all of the engineering analogies to support dubious understanding of the topics raised in the thread.
But you missed my point. FT/lbs (feet per pounds(force)) has nothing to do with torque.
LbsFt is work done.
FtLbs is torque.
Do not try to confuse us by mis-quoting terms and abreviations.
I have read the thread and all of the engineering analogies to support dubious understanding of the topics raised in the thread.
But you missed my point. FT/lbs (feet per pounds(force)) has nothing to do with torque.
LbsFt is work done.
FtLbs is torque.
Do not try to confuse us by mis-quoting terms and abreviations.
OK
ft x lbs = lbs x ft -same units
uh huhh.
dubious engineering analogies... you mean like car analogies?
Sorry to attack you personally but the car analogy has no relevance. A car engine applies a force to increase the velocity, it does not oscillate like a speaker does. A weak engine will cause a car to acclerate slowly, a speaker motor moves the cone at an oscillatory frequency, A weak motor or heavy cone will reduce excursion at a given frequency and power input but if the Sd is larger it may not matter(depends on specifics)
Car acceleration is a function of mass and motor power, (simplified)
We dont care about speaker acceleration, we care about spl, which is a function of mass, motor power, and Sd (again simplified).
Hi,
"work done" not equal to "torque"
The order of the units in the abreviations are important to the meaning. They are NOT interchangeable.
no! they are different.
"work done" not equal to "torque"
The order of the units in the abreviations are important to the meaning. They are NOT interchangeable.
commutative law of multiplication - unless you guys are trying to reference some convention that you learned, which is ok.
Read again -same units
they are both a force applied over a distance.
Maybe where you are at but here I hear lb-ft of torque and ft-lb of torque, same thing they ARE interchangable. That's why people say 280lb-ft of torque, or 280ft-lb of torque, or the truck did 8000 ft-lb of work on the trailer. Notice how work and torque appear in the sentence despite the units.
I think we are arguing semantics here.
"...they are both a force applied over a distance."
No; torque is a force applied *at* a distance and need not produce any work at all, like a bolt that doesn't loosen.
Same units does not mean the same thing; if they did then dimensionless parameters like the Reynolds number would all mean the same thing.
No; torque is a force applied *at* a distance and need not produce any work at all, like a bolt that doesn't loosen.
Same units does not mean the same thing; if they did then dimensionless parameters like the Reynolds number would all mean the same thing.
excuse me for bad wording, good job nailing me for it.
Maybe that's why I said same units (twice)... again lb-ft=ft-lb, work does not equal torque, that's why when referring to torque you have to say torque and when referring to work you have to say work.(I think I said that already too.
Come on Cal, didnt you get the memo this is now a car forum.
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