Active speaker with a "too small" box and boost

[Troysi]

Assuming that amplifier power is clean and plentiful and that driver X-max isn't exceeded, is there any penalty or problem with building a "too small" sealed box, EQ'ing the response peak down and lifting the low end to match a more conventional rolloff?
Thanks!

[1Michael]

It depends...More information is needed.

[JonMarsh]

Agree with 1Michael. Generally, I can recommend the idea of using a small box sealed with a low Qts driver (which is pretty impossible to get extension in a sealed alignment) and EQ'ing it to extend the usable low end in a specific environment. For example, you might have a driver with a Qts of 0.3, if you put it in a fairly small box, this might raise the Fb over your desired target and still leave you with a Qtc of 0.5 or 0.6. Then some EQ below the Fb, say, up to 6dB, may get you what you want without getting you into significant power dissipation issues.

But what you describe is (with little info) sounds more like taking a higher Qts driver, say, 0.4 to 0.5, and putting it in a box that raises the Qtc above 0.707, so that the response is peaking, and then using EQ to remove the peak and extend the low end. Those are generally less sensitive drivers, so more power is needed, baseline or EQ'd. And that probably will still have some ringing behavior if the Qtc is 1 or more. EQ may not fix it.

Consider the Bose 901, the poster child for using EQ to extend the LF response. But with substantial issues. If you have the right equipment to investigate, it might make an interesting way to spend some dark and quiet winter hours...

Now, you could say my recent project update of the Isiris is bit like what you describe... small sealed box relative to the ideal for the drivers, in my case relying on room placement for boundary boost, an Fb of 34 Hz but F3 is 38Hz, for woofers with 14.3mm of Xmax... plenty of headroom to EQ to flat to 30Hz, if you want, but would need +6dB shelving boost. One could have reduced the size to about 75L, but then you'd definitely need the EQ boost, as it would have a steeper roll off.

[JonMarsh]

One suggestion- break out Unibox (free download for Excel, my long time favorite due to interface and graphs) or download VituixCAD (free standalone software, very capable, many tools built in) and explore the configurations you're interested in, keeping in mind power dissipation, step response, Xmax versus SPL, etc.