[Edgar77]

This is a two part comment. First I describe what I think I understand and then the question.

What I think I understand
In his videos and on his website Danny shows often the frequency responses from speakers. When he designs crossovers he makes sure the woofer and tweeter work well together. And he adjusts the crossover frequency depending on the individual speaker and drivers.
It seems the lowest frequency of all speakers is not controlled. It just goes as low as possible and it rolls off at different low frequencies depending on each speaker (and I think also depending on the room, etc.)
Danny suggests for many of his own speaker designs to add subwoofers for the real low frequencies. And with the direct servo amps the “high” frequency and other parameters of the subs can be adjusted to match with the stereo speakers.

Now what I like to understand
Does it make sense to let the stereo speakers play the low frequencies as low as they can and then adjust the sub(s) so that they take over from there and play the even lower frequencies?
Or wouldn’t it be better to control the low frequency of the woofers in the stereo speakers to play not as low as they can but to let them roll off at i.e. 100 Hz and then let the subwoofers take over from that frequency? (The 100 Hz is just an example.)
I guess what I am asking is in a way: Wouldn't it be perfect if Danny would design the crossovers in the speakers so that not only the low frequency of the tweeters are set but also the low frequency of the woofers are set to match perfectly with a certain sub and servo amp?

I don’t have any of these speakers or subs in the moment so that is until now a theoretical question. I try to understand the whole setup with stereo speakers and subs. I searched Danny’s video but I didn’t find any video specifically about subs.

[Early B.]

Danny sells a device that allows you to cut off the bass frequency of your speakers to only allow the subwoofer to handle "higher" low frequencies. Alternatively, you can make this high pass filter yourself. For more info, start here:

https://www.audiocircle.com/index.php?topic=166817.msg1771673#msg1771673





 

[BobM]

If you look at this typical frequency response diagram you will see the individual driver curves (in color) and the resulting signal  (in black). Just adjust this down to the 50-70Hz region where the green woofer starts rolling off and you can imagine the sub crossing in. So many people think they have to set their sub high end crossover too high, to intercept the low end of the speakers woofer. If you look at the diagram, the proper way to set the sub is "below" the low roll off of the woofer, then adjust the sub's volume until you get a result that flattens out the overall response of the bottom end.

There's really no need to add complexity into the crossover to roll off the woofer any sharper. It does that pretty naturally on its own.

[Early B.]

To keep it in perspective, overlapping low frequencies isn't a problem in need of a solution. Very few audiophiles use high pass filters. If I owned full range floor standers, I'd still run them with stereo subs.