box size vs. transient response

[Guiria]

Is there a direct relation between box size and transient response?

Or...

Is transient response primarily governed by the quality of the driver?

 

[Swerd]

Is there a direct relation between box size and transient response? Or...

Is transient response primarily governed by the quality of the driver?

I don't believe there is a simple direct relationship between box size and transient response.

The driver, as far as I know, is the main source of fast or slow transients. In the lower bass frequencies, poor cabinet design, with a Q > 1.0, that creates an exaggerated bass hump around 50-100 Hz, also generates slower transients, or ringing, from an other wise good bass driver.

 

[annunaki]

I don't believe there is a simple direct relationship between box size and transient response.

The driver, as far as I know, is the main source of fast or slow transients. In the lower bass frequencies, poor cabinet design, with a Q > 1.0, that creates an exaggerated bass hump around 50-100 Hz, also generates slower transients, or ringing, from an other wise good bass driver.

Well stated!

 

[TLS Guy]

Total system Q

The size of the box is determined by the Thiel Small parameters of the driver. However the final result can be tweaked. Drivers have mechanical and electrical resonances. The box has a resonance. These resonances have notches of varying steepness. This is the Q of the resonance. The sum of all the above is total Q. If the total Q of the system is 0.5 the bass will have a tight quality, that I think is just the wrong side of natural. If the Q is greater than 1.0 it will be boomy. I like a total system Q between 0.7 and 0.8

 

[annunaki]

If the total Q of the system is 0.5 the bass will have a tight quality, that I think is just the wrong side of natural. If the Q is greater than 1.0 it will be boomy. I like a total system Q between 0.7 and 0.8

I agree!!

 

[Warpdrv]

If the total Q of the system is 0.5 the bass will have a tight quality, that I think is just the wrong side of natural. If the Q is greater than 1.0 it will be boomy. I like a total system Q between 0.7 and 0.8

How do you calculate what the Q will be for your boxes?

 

[annunaki]

For sealed enclosures it is pretty straight forward and important when using a modeling program. Finding the ideal enclosure for for ported, the formula is:

Enclosure volume: Vb = 15 Vas (Qts^2.87)

Theoretical cut-off frequency: F3 = 0.26 Fs (Qts^ -1.4)

Tuning frequency: Fb = 0.42 Fs (Qts^ -0.9)

^ is equal to squaring or the power of

 

[TLS Guy]

How do you calculate what the Q will be for your boxes?

I use BoxPro

 

[Warpdrv]

I use BoxPro

Do we have a link for this software...?

 

[TLS Guy]

You can purchase it.

It is not available as a download. You can purchase it for $129 from Madisound. For $199, you get X-Over Pro as well. There really is no point in having one without the other, in my opinion.

http://www.madisound.com/catalog/product_info.php?products_id=1453&osCsid=7e081efbc7db685d31a327e62c60be5d

 

[Warpdrv]

Thanks TLS.... Appreciate it...