Can anyone help with Alignment?

[3ll3d00d]

In terms of the target curve I'm initially aiming for, its fairly basic, +2db, flat across the mids and a -2db slope:

It's an in room target not necessarily a speaker design target, I wouldn't necessarily conflate them

 

[Robbie010]

Evening all,

I was just re-assessing the EQ-ing of the original native driver sweeps and took another look at the woofer. The native sweep shows a rather large peak just before the chosen 1.2khz crossover point. I have 6 EQ's to play with and can get a fairly flat response with 5 EQ's up to around 1.1khz.

What I'm wondering whether it is advisable to apply this EQ and set the crossover after the 5th EQ, closer to 1khz or should I EQ the native response well beyond this point?

 

[3ll3d00d]

I think it's highly likely you're eq'ing the room/position rather than the speaker with the above, ie I would say most, if not all, of the above is unwelcome

 

[voodooless]

I think you should fix that issues regardless of exact crossover point. Check the datasheet to see what is probably from the woofer, and what might be room interactions, or baffle diffraction. In this case the bump at 1.2 kHz is a property of the woofer, so good to fix.

Don’t you have some PEQs on the input? If so use those for the room effects and some overall shaping. That will free up some more for the woofer.

 

[Salt]

You might take that dip as the start for the roll-off of LP filter and leave it as is.

 

[voodooless]

You might take that dip as the start for the roll-off of LP filter and leave it as is.

Yup, a simple shelve should be fine to fix this.

 

[Robbie010]

This is the woofer published frequency response and my measurement side-by-side:

 

[Robbie010]

Yup, a simple shelve should be fine to fix this.

In that case, do I EQ the response between 100hz - 1khz and then set the crossover point at around 800hz to try and align the roll-off with the dip?

 

[voodooless]

I’d for now just fix the dip at 550 Hz and 1.2 kHz. The shelve would be able to fix the tilt. Baffle width would tell you roughly where the midpoint should go (baffle step).

 

[Robbie010]

Like this:

High Shelf at 250hz + EQ's.

 

[voodooless]

Looks better. But:

I would fix these two. Then the trend past 1 kHz is still upward. You can fix that with a higher filter order, or another shelve. Either way it costs extra biquads… best to experiment what works best.

 

[Salt]

I would leave at is and put a LPF around 900-1000 Hz (LP4) first and look at the rolloff. According to manufacturer's FR the dips might be generated localy (room...). and to be corrected 'overall' after the crossovers are finished.

 

[voodooless]

The first one possibly, the second one is not.

 

[Salt]

The second one could dip/drown with crossover (supporting it).

 

[voodooless]

The second one could dip/drown with crossover (supporting it).

I don’t think so. Look at the off-axis from the datasheet. The dip gets worse there.

 

[Salt]

I don’t think so. Look at the off-axis from the datasheet. The dip gets worse there.

Would be no obstacle to do the xover first and see how that works , also off-axis. That's my personal approach, and often you get results never estimated.
That's why I very appreciate DSP: change the settings, measure, look what you get, within a minute. But you always have to find the starting point.

 

[Robbie010]

Don’t you have some PEQs on the input? If so use those for the room effects and some overall shaping. That will free up some more for the woofer.

I just looking at this, there are 2 DEQ’s on each input, I’m not exactly sure what these are meant to be uses for?

 

[voodooless]

I just looking at this, there are 2 DEQ’s on each input, I’m not exactly sure what these are meant to be uses for?

These are a kind frequency dependent compressors. Come in handy in limiting bass excursions with high volume.

 

[3ll3d00d]

I would try this tweak to try to deal with the issues above the intended range

New 12" Full-Range: Fane 12-250TC

the bigger brother of the Fane got a cone treatment / tweak https://www.diyaudio.com/community/threads/how-to-make-a-loudspeaker-sandwich-cone.402917/post-7467924

www.diyaudio.com

Seems pretty cheap and easy to do.

Why are you using full range driver as a woofer btw?

 

[Keith_W]

How to tell if a dip in the FR is due to XO point phase cancellation or a room mode: measure at 1m, 2m, 3m. Overlay all the graphs. If it is a room mode, the dip will shift. If it's due to XO phase cancellation, the dip will stubbornly remain where it is.