Minimum Phase, constant delay (aka linear phase), whazzit?

[levimax]

Absolutely. First, fix the acoustics. Part of the problem with room correction aside from the positional aspect was discussed in the subwoofer thread, in that big problems in room response that create zeros (dips) mean there is energy STORAGE in the room. Adding more to that storage is, err, problematic in most cases.

Can you make the room acoustics analogy that "fixing the acoustics of too small a sub enclosure by making it bigger is better accoustcally than using DSP" ?

 

[j_j]

Can you make the room acoustics analogy that "fixing the acoustics of too small a sub enclosure by making it bigger is better accoustcally than using DSP" ?

I could, but I might be making a bad analogy. A too small sub enclosure can't be linear, and you'd need positional feedback to make it work. Yes, some subs of that sort do exist.

Consider. If the cone can change the interior volume of the enclosure by 10%, that changes the spring constant the cone is working against by 10%, etc.

 

[gberchin]

Until you get to modern video codecs that have 5 or 6 frame minimum latency and memory.

Sure, but in my living room I am at the mercy of the audio/video sync provided by the cable company, or the streaming service, or etc. And they tend to synchronize their audio with their video. So if my audio processing adds additional delay beyond a few tens of milliseconds, I get lipsync problems.

 

[gberchin]

... big problems in room response that create zeros (dips) mean there is energy STORAGE in the room. Adding more to that storage is, err, problematic in most cases.

Interestingly enough, I just implemented an experimental Double Bass Array in my listening room. In theory, it absorbs some of the bass energy. Well, I'm not certain that "absorbs" is quite the appropriate term. But the measured results in my room are very encouraging. In short: it works.

 

[j_j]

Interestingly enough, I just implemented an experimental Double Bass Array in my listening room. In theory, it absorbs some of the bass energy. Well, I'm not certain that "absorbs" is quite the appropriate term. But the measured results in my room are very encouraging. In short: it works.

It's not impossible, but it has to be done very precisely.

 

[danadam]

modulo the annoying scaling issues with Matlab plotting.

sorry for the squished plot, but the autoscaling is a pain to fsck with

Any reason why not to set the axes manually?

 

[DWPress]

I've played with this by creating the exact same filter sets in FIR and IIR via plugins and alternating with another plugin A/B switch. Sited listening I can't hear any difference but I know my filters are good to start with. To make it even more interesting I create my filters for an active XO 3-way speaker + 2 subs (8ch) via REW and rePhase but hosted by Mitchco's Hang Loose Convolver which allows me to switch with zero latency. For kicks I created the same filters in rePhase using min, lin and mixed phase filters for the XO which is very audible across the whole frequency band and all my corrections are below 350Hz.

I haven't done any proper measurements to determine phase issues interacting with the room and the FIR vs IIR filter sets yet. A little more room treatment behind the speakers and I'll dive into a more thorough set of measurements.

If you're creating filters tight enough for only one place in time and space, you might as well switch to headphones.

 

[j_j]

Any reason why not to set the axes manually?

Laziness.

Well, and having to adapt to a fixed-ratio box for the data, too. Since I can expand and stretch the plot box...