Car Audio Advice from the Audio Gurus: Use "Search thread" before posting a new Q!

[low_bass_makker]

Originally Posted by vebmetal

Maybe it was my virgin ICE ears, but sk456's components (Rainbow?) seemed to do this quite well!

They have good mid bass but they don't substitute a sub.

[navin]

Originally Posted by vebmetal

Maybe it was my virgin ICE ears, but sk456's components (Rainbow?) seemed to do this quite well!

think about this....

to create bass you need to move air. just how much air is determined by a 2nd order polynomial based on the surface area, volume of displacement, etc...

now to move air you need Sd (area of cone) and Xmax (displacement of cone). the equation is not linear that means that a 12" cone that moves 6mm will not produce twice the SPL of a 12" cone that moves 3mm. I will to find my old notes (I had worked with these equations in 1978-86) to get the exact details but from what I remember is that you need about 4 times the Xmax to double SPL (for a given cone dia).

So a 6" woofer (Sd about 150cm2) will have to move 11mm to reproduce the same level of bass of a 12" woofer (Sd about 400cm2) that has moved just 4mm. Now 11mm of LINEAR ONE WAY movement is a lot to ask of a 6" woofer and just about any 12" woofer is capable of 4mm. I hope this helps.

[anupmathur]

Of course that is a good and valid mathematical explanation.

But isn't this something that has a LOT to do with how loud you want the bass?
Conceivable that at low listening levels, six inch units might be 'satisfactory' for some!
The problem would come if six inchers cannot audibly reproduce 60 or 70 Hz at all.

[navin]

Originally Posted by anupmathur

But isn't this something that has a LOT to do with how loud you want the bass?
Conceivable that at low listening levels, six inch units might be 'satisfactory' for some!
The problem would come if six inchers cannot audibly reproduce 60 or 70 Hz at all.

Sure. but I thought we were comparing the bass output capabilities of a 6" component speaker to that of a dedicated subwoofer (12" is the most available size).

A good 6" speaker (Rainbow, Illusion Carbon, Infinity Kappa, DLS, Hertz Mille, Boston Pro, Polk Momo, etc...) can produce very good quality of bass down to 60hz or so at reasonale SPLs (95db+). This bass will make music very enjoyable and the brain (in most cases) will be fill in the last octave hence giving the impression that the speaker is playing lower than it really is. The listener does not realise this untill he/she listens to the same system supported by an able subwoofer. I know becuase by father in law and mother are both addicted to the bass a subwofoer can provide. Both wanted a subwoofer in their cars even if it meant reduced trunk space and the added cost of an amp, wiring etc..and they are in their 70s!

Just imagine what the sub will do for a 20 something who listens to 2pac and 50cent instead of Elvis.

Good component speakers can produce resoanble bass down to 60Hz (6") or 90Hz (5") but 60Hz and 90Hz is not low bass. It is more like midbass and hence these drivers are often called midbass drivers. Bass is usually refered to as frequencies below 40/50hz - the last octave (20-40Hz or 25-50hz) depending on your needs, definition, and application (PA bass reinforcement speakers for example rarely go as low at 20hz).

I hope this clears things. Sorry for any misunderstandings.

[anupmathur]

Brilliant explanations as always, Navin!

But here you kinda missed it:

Originally Posted by navin

Just imagine what the sub will do for a 20 something who listens to 2pac and 50cent instead of Elvis.

2pac and 50cent have copious amounts of bass in their music and it IS possible to enjoy them without having a sub.
Now, Elvis.....ahem.... that is from the archives, when the art of putting so much bass into a recording was in its infancy!

____________________________________________just kidding.

[zucchero]

well the best midbass i have heard is of dyns.i have set them at 63 hz 12 db slope and believe me they will put some woofers to shame.the bass is as tight as you can think of.
listen to pink floyd,chicane,dire straits and you wont feel that the system is running without a sub.but howver good your 6" midbass is their is no way it can compensate a sub.you NEED to have a sub(50 hz -20hz) to complete the entire spectrum.

[BHAGWAN]

Originally Posted by zucchero

well the best midbass i have heard is of dyns.i have set them at 63 hz 12 db slope and believe me they will put some woofers to shame.the bass is as tight as you can think of.

but howver good your 6" midbass is their is no way it can compensate a sub.you NEED to have a sub(50 hz -20hz) to complete the entire spectrum.

I cut mine @ 100 Hertz & @ 6dB [1st order] - Front Comp - Dynaudio i.e.

Sub is always needed.

I cut my sub @ 80 Hzs - 2nd order - 12 dB per octave.

[zucchero]

yes 'B' even i will cut them at 80hz once i have my subs.as of today i am running without subs and to be honest in some tracks i hardly miss them

[DerAlte]

Originally Posted by anupmathur

... But here you kinda missed it:

2pac and 50cent have copious amounts of bass in their music and it IS possible to enjoy them without having a sub...

Mathur-saheb, you would be losing 50% of the enjoyment of hip-hop if you don't use a sub - that is the lowest 2 octaves produced by the synthetic bass in this genre, which the mid-bass drivers do not handle.

Elvis, on the other hand, didn't need bass to get his music across - the string bass (mostly unamplified) accompaniment in Rock from those days didn't go that low. But the other music - western classical - etc. did use wind and other instruments that needed a sub. The recordings DID have content below 60Hz. Just try out some good vinyl from those days, 20Hz-20Khz was a reality even in the 60's, sir, albeit that the dimensions and costs were quite significant.

[BHAGWAN]

I cross them over @ 100 Hzs - not @ 80 Hzs.

Buy that sub. It is needed. Do not strain the driver & door panels etc.

[anupmathur]

Originally Posted by DerAlte

Mathur-saheb, you would be losing 50% of the enjoyment of hip-hop if you don't use a sub -

I regret having to say I use Bose 901 Series VI, and used 901 Series III before that. That accounts for the last 30 years.
But I do concede that even the 901s benefit by using the Bose Cannon, though I frankly never could afford one.

I agree that 20 to 20 was a reality even back then. But I would request you to point me to tracks in classic rock (that's the genre I listen to) that have content below 40 or 50 Hz.

[greenhorn]

Oh, a bose fan ( !)
Anyway, Even if you have a 6 incher which has a good excursion, your mids will suffer. the nature of the magnetic field in the center may not be the way it is at the extremes, and can cause Inter modulation distortion

[anupmathur]

Originally Posted by greenhorn

Oh, a bose fan ( !)
Anyway, Even if you have a 6 incher which has a good excursion, your mids will suffer. the nature of the magnetic field in the center may not be the way it is at the extremes, and can cause Inter modulation distortion

Yes, thank you!
And I would need Navin's help with the rest of this post!
My understanding of magnetic fields is not what it used to be.
And this 'new' concept of IM distortion I am not at all familiar with.

Navinji, please!?

[DerAlte]

Originally Posted by anupmathur

I regret having to say I use Bose ... never could afford one.

Sirji, we are talking of ICE!

Originally Posted by anupmathur

... But I would request you to point me to tracks in classic rock (that's the genre I listen to) that have content below 40 or 50 Hz.

Sorry sir, next time I will definitely carry a spectrum analyser!

[Bass&Trouble]

Originally Posted by anupmathur

Of course that is a good and valid mathematical explanation.
But isn't this something that has a LOT to do with how loud you want the bass?

mathur-saahab, maybe you are drawing a parallel with 5-6" drivers used for home speakers. Many good home hi-fi ones will be humoured at the challenge of playing into the sub bass region. But in car audio, manufacturers know that the drivers will end up in doors - of volume and integrity unknown, and even worse, parcel shelves. For this reason, drivers are designed to operate in the safe region. And sub bass is best left to subwoofers. Even top end 5-6" drivers will be no match for the bass possible from mid-fi home audio drivers in their respective scenarios.

Originally Posted by zucchero

well the best midbass i have heard is of dyns.i have set them at 63 hz 12 db slope and believe me they will put some woofers to shame.

If you do this once again I will report you to the mods for shameless self-promotion.