I have been building my large bookshelf loudspeaker project. I use 10” car audio subwoofers as the woofers. I built closed enclosures with Qtc of 0.5 for them. They offer decent bass response. However, I think it’s a bit too low efficiency. So, I’m thinking to apply the active bass equalization circuit to them.
Firstly, I’m not sure if I could call it as the “Linkwitz Transform” circuit.
Secondly, I’m not certain which frequency should be the center point. And how much level for the boost? If I’m not wrong, the Qtc of 2.0 would yield a boost level of +6dB.
Consequently, finally, should I build the Linkwitz circuit with Qtc of 2.0 at the box resonance, 38.5Hz regarding the attached?
Firstly, I’m not sure if I could call it as the “Linkwitz Transform” circuit.
Secondly, I’m not certain which frequency should be the center point. And how much level for the boost? If I’m not wrong, the Qtc of 2.0 would yield a boost level of +6dB.
Consequently, finally, should I build the Linkwitz circuit with Qtc of 2.0 at the box resonance, 38.5Hz regarding the attached?
Attachments
The datasheet you've attached shows an Xmax of 0.23 inches or ~6mm. If I were you I'd see how low it could go for that Xmax and what power & SPL it would take / give. If you try to go too low, you'd be limited by amplifier VA / Xmax.
This is the calculator I have used. https://www.trueaudio.com/st_lkxfm.htm. (There is a link to an excel sheet on the page).
There is also a tweaked version of this on Rod Elliot’s sound-au.com pages.
You can see the before and after and compensation level.
I use this with pairs of 5 1/4” drivers and I get very tight punchy bass. However, if I push the response of the filter too low, then bass heavy tracks cause excursion limiting at medium volumes.
As a result, I don’t add too much bass, but have a compromise I can live with. You have a much better starting point than me with a 10” driver.
There is also a tweaked version of this on Rod Elliot’s sound-au.com pages.
You can see the before and after and compensation level.
I use this with pairs of 5 1/4” drivers and I get very tight punchy bass. However, if I push the response of the filter too low, then bass heavy tracks cause excursion limiting at medium volumes.
As a result, I don’t add too much bass, but have a compromise I can live with. You have a much better starting point than me with a 10” driver.
I don't know if this helps you model the effects, but you can apply a LT (and other basic HP/LP slopes) in VituixCAD's enclosure tool:
e.g. here's a Dayton RSS390HF in a 90L enclosure with an LT to net a < 30Hz F3.
Also beneficial is excursion modeling (not shown). The 180w level is where xmax is reached due to LT being applied (14.5mm @ 21Hz).
A number of DSP platforms are supported, so you can export the parameters of your filter(s).
e.g. here's a Dayton RSS390HF in a 90L enclosure with an LT to net a < 30Hz F3.
Also beneficial is excursion modeling (not shown). The 180w level is where xmax is reached due to LT being applied (14.5mm @ 21Hz).
A number of DSP platforms are supported, so you can export the parameters of your filter(s).