Martin King did some simulation of drivers with varying Qtd—0.2 to 0.8 in his front horn paper with interesting results.
As in everything, relying on only one parameter to come up with a mantra is not the best approach.
Drivers have a set of parameters, and they have to be taken as a whole.
I, too, have been surprised from drivers that didn't have the "right" Qts (according to some) that simulated very well after all the info had been plugged in.
Drivers have a set of parameters, and they have to be taken as a whole.
I, too, have been surprised from drivers that didn't have the "right" Qts (according to some) that simulated very well after all the info had been plugged in.
This woofer was recently being tested at hifi-selbsbau;
https://hifi-selbstbau.de/index.php/hsb-datenblaetter/breitbandchassis/sb-acoustics-sb20frpc30-8
Very impressive performance!
Makes you wonder why they don't add the same perks to the rest of the PFC range!
https://hifi-selbstbau.de/index.php/hsb-datenblaetter/breitbandchassis/sb-acoustics-sb20frpc30-8
Very impressive performance!
Makes you wonder why they don't add the same perks to the rest of the PFC range!
I dont have a subscription, so I will have to take your word for it. They do very nice and elaborate testing though. For many fullrange drivers, the results are kind of shocking if you believe that frequency response should be linear from the start, dispersion should be 100% or staggered like Floyd Tools recommends. 😬🤣
@Pierrick59, I've modeled that driver in WinISD and it wants a good sized enclosurte to get any kind of a low end w/flat respnse.
You probably should not go lower than 65 to 75 litres for vented and that will yield an F3 around 40 Hz.
A 28 liter enclosure is pretty flat and nicely damped with an F3 around 65 Hz.
I think the ideal enclosure for this drive could be the transmission line suggested above or the 28l sealed if you want bookshelf. And that would be very large for a booksehel speajker. You could go smaller sealed if don't mind even less bass and a response peak before rolloff.
You probably should not go lower than 65 to 75 litres for vented and that will yield an F3 around 40 Hz.
A 28 liter enclosure is pretty flat and nicely damped with an F3 around 65 Hz.
I think the ideal enclosure for this drive could be the transmission line suggested above or the 28l sealed if you want bookshelf. And that would be very large for a booksehel speajker. You could go smaller sealed if don't mind even less bass and a response peak before rolloff.
i have finished my building DDVP20+ SB20 i have strictly follow the plan and and the damping, it's their first 20 hour
i'm little surprise i was thinking i could have more bass.....
on the plan it's writed 75gr polyester wool, do you think if i put less it plays on the lower frequency?
for the sound it plays really nice and not a big difference with the MAOP 10 just near
i'm little surprise i was thinking i could have more bass.....
on the plan it's writed 75gr polyester wool, do you think if i put less it plays on the lower frequency?
for the sound it plays really nice and not a big difference with the MAOP 10 just near
That is quite the performer then.
A pair of MAOP10 are about $500, and a pair of sb20frpc30 are $120. Nice!
If one is limited, then yes, using the SB20 in a transmission line is a good idea, I can get it down to 40Hz, but it needs a bit of EQ to tame the mids.
Best case would be to use the SB20 down to 80-100Hz, and let subwoofers take over. That's the DDVP20, with its knee at 80Hz.
Even better would be a design with the SB20 wide range, and woofers taking over the 300Hz and below... but that is another story.
As always, it is a compromise. Use one driver to play all, you can't get very low, or very high. Distortion will rise quickly.
the low frequencies are not bad but i was thinking to make better with sb20 because it's bigger but at the moment (begining running in) there is not a so big difference
and for those wich think about it, it don't cry at all, there a little bit less high frequencies (than my maop 10) but it's not a problem at all. it's a really a better investment than my chr70 that i was having before.
the faital 15PR400 is really too high in price compare to the cost of the sb20.... (here in europe faital is approx 290 eur and the sb20 45 eur)
i repeat my question do you think reduce damping (polyester wool) will encrease bass?
and for those wich think about it, it don't cry at all, there a little bit less high frequencies (than my maop 10) but it's not a problem at all. it's a really a better investment than my chr70 that i was having before.
the faital 15PR400 is really too high in price compare to the cost of the sb20.... (here in europe faital is approx 290 eur and the sb20 45 eur)
i repeat my question do you think reduce damping (polyester wool) will encrease bass?
My 2 cents Pierrick, I've not followed this thread but from my knowledge of using such types of materials etc in my industry, they're are normally spec as thickness & density per m2. Just weighing the stuffing may not produce the results. Off course the other thing is you have to experiment with the quantity of stuffing used.
Well, the Faital is also much bigger!
How about the SBAudience? (sister company of SBAcoustics)
Or... use the TL with a real woofer from SBA, and the SB20 in a sealed chamber 300Hz and up. If you have the space in your room, the SB20 could also be open baffle.
The stuffing is mostly there to take care of unwanted harmonics going through the port.
Less stuffing will probably give you a couple dBs of bass, at the detriment of more unwanted frequencies coming out as well.
I don't want to derail the thread but the Faital is excellent value. I really hadn't planned on getting one (way too big) but got a deal I couldn't refuse. They go high smoothly, have a nice lightweight cone and can be used in many configs.
As to stuffing, I've only used mine in a very lossy box heavily stuffed with foam. I'm running them without eq. They're definitely worth further work.
As to stuffing, I've only used mine in a very lossy box heavily stuffed with foam. I'm running them without eq. They're definitely worth further work.
Wow, Faital Pro15PR400 at $459- here in Aus!
And that's for one, so a pair makes it $918-, just a bit less than a thousand dollars. Before delivery.
This can not be excellent value in the world I live in.
SBAudience definitely offers better deals in 15" woofers.
I think I'll stick with my old Kawai 38p24 from old Kawai organs.
And that's for one, so a pair makes it $918-, just a bit less than a thousand dollars. Before delivery.
This can not be excellent value in the world I live in.
SBAudience definitely offers better deals in 15" woofers.
I think I'll stick with my old Kawai 38p24 from old Kawai organs.
Mate,
4 - 5 years ago is hardly relevant.
Check DJ City's price now:
https://djcity.com.au/product/faital-pro-fa-15pr400-15-inch-lf-driver/
4 - 5 years ago is hardly relevant.
Check DJ City's price now:
https://djcity.com.au/product/faital-pro-fa-15pr400-15-inch-lf-driver/