Why are guitar cabs 12 inch and bass cabs 10 inch?

[ecc83]

This link..
Barefaced Bass - Why nominal diameter tells you nothing about tone

Provided by Dug dog tells it all. The guy nails the "size matters" myth (yes you need a large swept volume to couple efficiently at low frequencies but whilst multiple small cones will work they are not necessarily the most economic solution).

He also puts to bed the myth that 15" speakers are "slow" and lack HF response. We have a 200W Fane 15" in a 6cu ft ported cab* (Celestion design) and if we run a sixer thru' it it sounds very sweet. If hit with 20watts (HT-20) it nowhere near breakup so all you hear is the amp. What it does NOT have is any lack of treble! Sure, it does not have the upper mid bite of a V30 but it is brighter than our Greenback (12" 55Hz jobby). It will not disperse HF as well as a 12 or 10 but in our tiny room we are forced to harken on axis!

*And all it has done for the past 5 years is prop up my printer scanner!

Dave.

 

[CMB Studios]

This link..
Barefaced Bass - Why nominal diameter tells you nothing about tone

Provided by Dug dog tells it all. The guy nails the "size matters" myth (yes you need a large swept volume to couple efficiently at low frequencies but whilst multiple small cones will work they are not necessarily the most economic solution).

He also puts to bed the myth that 15" speakers are "slow" and lack HF response. We have a 200W Fane 15" in a 6cu ft ported cab* (Celestion design) and if we run a sixer thru' it it sounds very sweet. If hit with 20watts (HT-20) it nowhere near breakup so all you hear is the amp. What it does NOT have is any lack of treble! Sure, it does not have the upper mid bite of a V30 but it is brighter than our Greenback (12" 55Hz jobby). It will not disperse HF as well as a 12 or 10 but in our tiny room we are forced to harken on axis!

*And all it has done for the past 5 years is prop up my printer scanner!

Dave.

he can put whatever he wants to bed... fact is... every time i hear a 115 or a 215 vs a 210 or a 410.... the 15's sound mushier and the 10's sound crisper and punchier...

so in my ears... he put nothing to bed, regardless of whatever tests he's performed.

 

[Greg_L]

I don't give a crap about the myths, facts, or science. I let my ears be the judge. I'll take 10's for bass over 15's any day.

 

[Lt. Bob]

15's are mushy even though they often can indeed go as high as any 12 or 10. But it's simply physics .... a 15" has a larger mass and is gonna accelerate slower than a smaller mass.
They definitely are slower and mushier sounding than 10's.

 

[ecc83]

15's are mushy even though they often can indeed go as high as any 12 or 10. But it's simply physics .... a 15" has a larger mass and is gonna accelerate slower than a smaller mass.
They definitely are slower and mushier sounding than 10's.

The cone of a 15" speaker reproducing 100Hz must accelerate from peak to peak displacement in exactly the same time as the cone of a 10 or 6 inch speaker, otherwise you ain't got 100Hz!

The difference is that the smaller cones would have to have a bigger pk-pk displacement to produce the same SPL as the 15......Bugatti Veryons agin!

Dave.

 

[Lt. Bob]

The cone of a 15" speaker reproducing 100Hz must accelerate from peak to peak displacement in exactly the same time as the cone of a 10 or 6 inch speaker, otherwise you ain't got 100Hz!
.

but it can't because it has a greater mass which is why the attack transients are slower than a 10 .......... period.

A 2 ton car will NOT accelerate as fast as a 1 ton car when using the same motor.
A 15" will NOT accelerate as fast as a 10" when using the same power (motor).

And my ears confirm that .... I understand you can't hear these things yourself but nonetheless I have played bass for 45 years and have played thru every combination of amps and speakers you can think of and 15's are mushy compared to a 10.
The sound and my ears don't lie.

 

[ecc83]

but it can't because it has a greater mass which is why the attack transients are slower than a 10 .......... period.

A 2 ton car will NOT accelerate as fast as a 1 ton car when using the same motor.
A 15" will NOT accelerate as fast as a 10" when using the same power (motor).

And my ears confirm that .... I understand you can't hear these things yourself but nonetheless I have played bass for 45 years and have played thru every combination of amps and speakers you can think of and 15's are mushy compared to a 10.
The sound and my ears don't lie.

To reproduces 100Hz a cone, any cone, must move from rest to the waveform peak in 5mSecs, thru centre (zero volts) to peak waveform in another 5mSecs the whole excursion taking exactly 10mSecs. To have it otherwise would mean different cone masses would not be in tune!

And whoever said the motor is the same ? 15inchers can have humungous magnets* and have bigger voice coils therefore the BL product is larger.

I agree that "transient response" can be poorer for bigger cones but that is a consequence of damping, stopping the bloody things! (lil test. tap the cone of a big speaker when it is unconnected...Boing! Now wire a short across the terms' Thud. That's damping and most "music" amps don't have much.

Tis true I have buggered ears and thank you for your concern but I probably hear 100Hz better than you! Not distracted by all the crap past about 2kHz you see!
And EVERYBODIE'S ears "lie" Called Stereophonic Sound!

*Just to add to the paradox that is speakers and what is "well known" but myth. Stronger magnets often lead to weaker bass (BBC monitor research).

Dave.

 

[Lt. Bob]

I agree that "transient response" can be poorer for bigger cones but that is a consequence of damping, stopping the bloody things!

and that's why they sound mushy compared to 10's

I probably hear 100Hz better than you! Not distracted by all the crap past about 2kHz you see

not a chance ...... not only have I been a player for 45 years but I've also been a piano tuner ( 3-5 a day 6 days a week till recently a ) and an engineer for 40 years and my ears still work. I have an enormous amount of ear training under my belt..

And EVERYBODIE'S ears "lie" Called Stereophonic Sound!

That would be EVERYBODY'S and stereophonic sound and the many things thyat are wrong with that has absolutely nothing to do with hearing if a 15 is mushy compared to a 10.

You can dredge up all the 'facts' you want to but one fact is: I have VASTLY more experience with bass than you do and 15's are mushy sounding compared to 10's regardless of any arguing over the exact reasons for that.

 

[mixsit]

Woofers' have less hi freq amplitude than tweets' because they are heavier. A lot of what's being kick around here is probably centers more around differences in upper freg response than the fundamental tones.

 

[muttley600]

Can I offer my ears as being equally buggered and better tuned to listening to stuff than anyone else...

Truth is as with many things people will cling to a single belief even when it is complexed beyond proof by other limiting and influential factors. Speaker response and performance is no different and if you want to claim certain performance characteristics you need to qualify them. No speaker will perform as per spec. Every frequency that is produced is coloured by others. The basic efficiency of the unit will make comparison difficult if not impossible. This whole debate is dumb. Use physics as a guide and your ears as confirmation.

 

[ecc83]

and that's why they sound mushy compared to 10's
not a chance ...... not only have I been a player for 45 years but I've also been a piano tuner ( 3-5 a day 6 days a week till recently a ) and an engineer for 40 years and my ears still work. I have an enormous amount of ear training under my belt..
That would be EVERYBODY'S and stereophonic sound and the many things thyat are wrong with that has absolutely nothing to do with hearing if a 15 is mushy compared to a 10.

You can dredge up all the 'facts' you want to but one fact is: I have VASTLY more experience with bass than you do and 15's are mushy sounding compared to 10's regardless of any arguing over the exact reasons for that.

Well, tongue was in cheek over my hearing! But if you are going to call me out on typos, don't do them yourself and "thyat" is a fact.

Muttley600? I THINK I agree with you! ??

dave.

 

[muttley600]

Well, tongue was in cheek over my hearing! But if you are going to call me out on typos, don't do them yourself and "thyat" is a fact.

Muttley600? I THINK I agree with you! ??

dave.

Lt knows where I'm coming from and he has a good grasp of this stuff too. Physics and acoustics in particular is my bag. I've been at it for over thirty years in conjunction with making the odd instrument.

You aren't agreeing with me or disagreeing with me, it's physics both pure and applied that we are forced to agree with.

 

[Greg_L]

Yall can measure internet dicks all you want, to my ears 10's sound better than 15's for bass. Maybe it's the cab, speaker design, room, planets lining up, I couldn't care less. 10's = better.

 

[muttley600]

Yall can measure internet dicks all you want, to my ears 10's sound better than 15's for bass. Maybe it's the cab, speaker design, room, planets lining up, I couldn't care less. 10's = better.

OK we get it. Nine out of ten gergs who expressed a preference said 10's kick ass. The other one couldn't give a.....

 

[ecc83]

Yall can measure internet dicks all you want, to my ears 10's sound better than 15's for bass. Maybe it's the cab, speaker design, room, planets lining up, I couldn't care less. 10's = better.

Did not say they were or were not!

Dave.

 

[Greg_L]

Did not say they were or were not!

Dave.

I didn't say you did!

It's really apples and oranges. And dildos.

 

[Ainaudio]

Bass and guitar amp and loudspeaker technologies are principle different.
Guitar amp has high distortion and low damping factor, uses high resonance speakers with limited frequency range, and many case - open back boxes.
Bass equipment is much closer to hifi or pro-audio gear.

 

[ecc83]

Bass and guitar amp and loudspeaker technologies are principle different.
Guitar amp has high distortion and low damping factor, uses high resonance speakers with limited frequency range, and many case - open back boxes.
Bass equipment is much closer to hifi or pro-audio gear.

Indeed. I know of a 4 x12 cab that had special 32Ohm 12's in it because putting bass drivers in series is a big no-no as indeed it is for hi fi speakers.

I once built a pair of line source speakers. 8x 8" drivers in each IIRC and they were paralled in pairs to give 4R and then four 100V line transformers used to get them back to the 100V o/p amp.

They were frigging heavy columns but loud and clean as ***t!

Dave.

 

[Ainaudio]

Serial connection kills damping factor, and it is what guitar amp needs, and bass amp no.
If there is such possibility to switch loudspeakers in serial and parallel (for example - 2 x 8ohms in 16ohms or in 4 ohms) and there are switchable or separated 16/8/4 ohm amp outs - try and compare 16 ohm with 4 ohm versions on guitar, serial 16 ohms will win !
Open back box is additional factor to lower damping and resonances, open box never will be boomy.
Concerning bass - only parallel loudspeaker connection (Ampeg uses 32ohm speakers for it), and closed or vented/resonator box.

 

[ecc83]

Serial connection kills damping factor, and it is what guitar amp needs, and bass amp no.
If there is such possibility to switch loudspeakers in serial and parallel (for example - 2 x 8ohms in 16ohms or in 4 ohms) and there are switchable or separated 16/8/4 ohm amp outs - try and compare 16 ohm with 4 ohm versions on guitar, serial 16 ohms will win !
Open back box is additional factor to lower damping and resonances, open box never will be boomy.
Concerning bass - only parallel loudspeaker connection (Ampeg uses 32ohm speakers for it), and closed or vented/resonator box.

Agreed. In almost every regard the "classic" 4x12 guitar cab is an audio designer's worst nightmare.
The cabinet is too small for 4 12 inchers. The panels are left to resonate with almost no stiffening or damping material. It is a closed box but far from airtight and, as you say, each driver "sees" the impedance of the other when in 16Ohm mode which is the preffered mode because that is what would have been used historically ("proper" power amps and speakers were always 15aka 16 Ohms in the begining). It also uses all the copper in the transformer and is thus more efficient...BUT!..

The SOUND of this leaky, rattly box is the one our gonads equate with rock and roll!

Dave