6 th order bandpass driver .qts?

[jayam000]

Going through the details of 6th order bandpass box design i reached the following page & info.

http://www.carstereo.com/help/Articles.cfm?id=32

One of the reasons bandpass enclosures are so popular is because of an inherent property they have that allows the enclosure designer the flexibility to trade bandwidth for efficiency and vice versa. This calculator will design a 6th order bandpass enclosure. This calculator is only for Qts values from 0.18 to 0.28.

Then i read the Bassbox Pro manual. Here is the said that the driver .qts be greater than .4 for double tuned ( 6th order) bandpass box. .

Puzzled here. guidance in the matter is required.

[Rademakers]

Doesn't it say Qts lower then 0.4 for 6th order? The old rule of thumb was to use a driver with a Qts similar to that used in reflex cabinets (so 0.3 -0.45-ish). Above 0.45 hangs towards a closed box/ 4th order IIRC.

In newer designs low Qts drivers (as simulated by that program) are used. They will work too and are in some groups prefered for high to very high power conditions. They do not always simulate as good as they sound for 6th order though.

Regards Johan

[Thawach]

This calculator is only for Qts values from 0.18 to 0.28.

jayam000, This's The new rule of thumb which the best performance. but u can use The old rule of thumb like Rademakers said but greater than 0.4 from bass box. don't forget the bass box use for car sub,they only want the spl and never mind with the best performance. the same it seems like to do with pa speaker.

regards-TW

[GM]

Originally posted by jayam000

This calculator is only for Qts values from 0.18 to 0.28.

Then i read the Bassbox Pro manual. Here is the said that the driver .qts be greater than .4 for double tuned ( 6th order) bandpass box.

I used HR to sim a design and as I suspicioned, it was a 'one note' boom-box, so IMO best to avoid this calculator.

As Johan noted, that should be < ~ 0.4 Qts for typical apps, though you can use up to a ~0.707 Qts for a max gain BW 'sub' if you have the space for a huge cab and PRs for vents to keep distortion low.

GM

[jayam000]

Thanks to all for nice guidance. I understand/conclude as :
For car i can use higher .qts & for home it is better to use lower .qts for performance. If vent is big use PR.

[GM]

You're welcome!

Hmm, from the postings I concluded that car audio typically wants a low Q driver to get the rising response required to blend well with its cabin gain while HIFI/HT can use whatever Q driver would be required a vented alignment which when TLs are included is anything below ~0.707.

GM