Speaker listening position FR targets

Actually a Helmholtz resonator could work...

 

I've done some thinking, and I've refreshed my knoweledge of ir, iir, fir, phase, crossovers and filters in general.

While it's true that the inner ear is a spectrum analyzer basically, so it's doing a constant spectrum messurements, the higher structures in the brain are integrators. And by integrating the fr and phase, you basically get impulse response, so, I'd argue we're listening to time domain. So in this sense, in the very low bass, the nature of the sounds is not very transient, so minimal phase is not that important as long as fr is fine, and trebble is just so fast that it's probably beyond the ability of the brain to properly integrate the phase, but for mids - oh yes, I think it's quite possible to smear the ir threre with excess or negative phase, and it'd be quite audible.

You were completely right.

However, my serious speakers so far were all 4, 5 way digital high slope crossovers, ob or bizzare omni pattern stuff, and they are mostly infact always minimum phase (measured too). So I was right not to worry about phase, but that's in my particular case.

For normal speakers with baffle step right in the middle of the mids, the only way is to do a proper FIR filtering to correct for the phase, if you want to do it right, basically the way you did it.

Nice.

 

So my speakers have almost no excess group delay from 100hz up. As flat as it gets, not considering reflections, of course.

Goddamit @Serious
Now I have to switch to FIR for everything because it's just better overall.
I'll have to make everything linear phase now due to my ocd.

Thanks very much

 

It's hard to measure in room, but excess phase is far more telling than excess group delay.
Hathor cardioid monitor has 0 degrees of excess phase.
Amon OB has some excess phase. It's the Voxativ which has some excess phase itself from the whizzer cone. Not as much as a 2nd order XO, though.

I just disassembled Hathor to upgrade XO parts and slightly adjust the filters. So the in-room response should be a tiny bit more linear afterwards, but nothing major. Maybe 1dB here and there.
They also need to be painted again and I might do that while I'm at it. But that's a longer process.

Edit: For FIR filters it's a compromise as to how much delay you're willing to have. I think I have my LS50 Meta at 10ms or so.

 

One is a derivative of another, no?
Unless you are measuring nearfield, the time delay will produce a phase shift that's more or less linear with frequency and can be ignored. Group delay arising from that is of no consequence because it' a minimum phase delay anyway. Any extra phase mangling is excess phase (correct me if I'm wrong) - this effectively causes excess group delay (if you do not account for reflections). It's just easier to read.

As for fir latency, I don't care one bit. It can lag 5 seconds for all I care.

 

Yes, but looking at it from the excess group delay will require lots of zooming between the lower and higher frequencies. 0.1ms is 360° at 10kHz, but only 3.6° at 100Hz.
If we want it to be within 1/100th of that, that's just 0.5us at 20kHz!
So I think the excess phase visualization is more useful here. For bass frequencies you could argue for excess group delay, though.

Thinking out loud: 1cm of tweeter offset makes a world of a difference in the crossover in practice and that's just 0.03ms.
Even for lower frequencies it can make a difference. That the woofer on my monitor speaker isn't flush is not a coincidence, the crossover wouldn't really work otherwise.

Lip sync, etc is a problem with latency. If it's just for audio then sure. Even 100ms would be fine and that should be plenty.

 

I realized that while I updated the other thread, I felt like I still had to update this one:


Doesn't look very different. The upper treble changed a bit, but it's mostly from angling the speakers closer to on-axis.

The first order looks really good, the 2nd order isn't really worth discussing.

I still feel like the 2 way sounds better, but tihs one is really close to my FR target now. Does it sound more neutral than the 2 way? Not really, IMO. The resulting comb-filtering from adding a tweeter makes it sound less smooth than it looks.

The 2nd order would measure better in a room with more reverb, but the directivity isn't as smooth. Hence why it's not that good in my room.

For the bass I was thinking about a sub with digital EQ closer to the listening position, but what I want isn't cheap. I may build it eventually since I want to see how much bass extension I can get...

 

Nearfield subs are really something to be experienced. The left and right subs are each less than 1m from my ears. X-over is 80hz 4th order LR HP/LP. I never had this detailed and textured bass before and when it goes deep the couch shakes for that tactile feeling. Dsp kinda required though, if not for delay it’s to chop off any peaks, not getting any dips in the subs range though.
Put on some Recondite and become one with the bass.