I'm studying the active bass equalizer system to be applied for my speaker system. I wonder whether the "B&W Bass Alignment Filter" and "Linkwitz Transform" are the same thing?
From my research, the B&W's, when installed, would alter the order of the bass loading system to a higher order, i.e., when used with the ported speakers, it will shift the original fourth order to sixth order system as explained in its brochure and many reviews. For the Linkwitz Transform circuit, it would delete the original alignment and create a new alignment instead, whilst retain the original number of order, i.e., a closed box with Qtc of 1.0 and Fb of 50Hz could be shifted to Qtc of 0.5 and Fb of 35Hz, STILL, the number of order will remain second order HPF. And for the ported system, it would not shift the order from fourth to sixth but remain the forth order HPF.
Is my understanding correct? In all, should I build the LT circuit myself from the online resources or buy the B&W's module (luckily, it allows user to change settings to suit various speakers as it's claimed itself to be universal use)?
The objective is to extend deep bass response of the closed enclosure speakers.
From my research, the B&W's, when installed, would alter the order of the bass loading system to a higher order, i.e., when used with the ported speakers, it will shift the original fourth order to sixth order system as explained in its brochure and many reviews. For the Linkwitz Transform circuit, it would delete the original alignment and create a new alignment instead, whilst retain the original number of order, i.e., a closed box with Qtc of 1.0 and Fb of 50Hz could be shifted to Qtc of 0.5 and Fb of 35Hz, STILL, the number of order will remain second order HPF. And for the ported system, it would not shift the order from fourth to sixth but remain the forth order HPF.
Is my understanding correct? In all, should I build the LT circuit myself from the online resources or buy the B&W's module (luckily, it allows user to change settings to suit various speakers as it's claimed itself to be universal use)?
The objective is to extend deep bass response of the closed enclosure speakers.
It looks like what the B&W’s filter does, extending bass along with increasing number of order, doesn’t it?
Which way is better between extending bass with (B&W’s filter) and without (LT circuit) increasing number of order?
Ordinarily, lower order has lower group delay (change in phase with the response rolloff). However don't forget the room is involved and changes what you get.
Okay, I think I got it.
Let’s move to another important thing to be concerned. Which bass loading system is more suitable with the active bass equalizer, between high Qtc (Qtc = 1.0) or low Qtc (Qtc = 0.5)? Because these two values have the same deep-bass-lack nature. For instance, the Qtc = 1.0 will give early bass roll-off, so it losses the deep bass. For the Qtc = 0.5, it will produce deeper bass due to the more gradual roll-off, BUT, lower SPL in that region. So which case is more suitable for collaborating with the active bass eq module?
That depends on the taste but I agree. A peak at that frequency will become annoying very quickly.
The order of the filter interacts with the tuning (no matter if sealed or ported) of the speaker. The result is a combination of both.
Don't buy the B&W module since you can get a full grown DSP for that money and then some. And that opens a whole range of new options the module doesn't even dream about.
I don't know what speakers you have but if it's some 2-way with a 6" woofer, forget about your 20 or even 30Hz goal, the excursion of the woofer will kill your midrange. I don't know what speakers you have but if you want to go really deep, get a subwoofer.
My 2c....they are both the same so far as both being EQs....but past that I see them as quite different.
The LT has the objective of maintaining a second order rolloff, while boosting the low end. Typically used for sealed.
The B&W has the objective of driving the low corner as deep and maximally flat as possible, and compensating for that with additional high-pass steepness.
Typically used for ported.
Sure, either alignment can be used on either sealed or ported...but it would be totally backarsewards to switch them from their typical usages, imo.
Moral or the story however you look at it...get a good DSP 😀
The LT has the objective of maintaining a second order rolloff, while boosting the low end. Typically used for sealed.
The B&W has the objective of driving the low corner as deep and maximally flat as possible, and compensating for that with additional high-pass steepness.
Typically used for ported.
Sure, either alignment can be used on either sealed or ported...but it would be totally backarsewards to switch them from their typical usages, imo.
Moral or the story however you look at it...get a good DSP 😀
If you want to boost the low end, do it on the tuning frequency of the speaker. If you try to boost it below that, you'll destroy your woofer because in that range a BR system does not restrict the movement of the driver at all. AT ALL! Which means, your voice coil will meet the back plate and then decide to cease working anymore.
Boosting at the fb is okay since that's where the excursion is the lowest, any EQing below is a no-no!
Boosting at the fb is okay since that's where the excursion is the lowest, any EQing below is a no-no!
So true for bass-reflex. You better put one heck of a steep high-pass in, barely below fB, if nuts enough to use a LT boost on it.
Like I tried to say before, the LT and the B+W are not remotely close to being the same animal functionally....ime/imo.