By the way, here are the calculated system response and phase graphs of the actual driver response with the actual used crossover components for those interested.

The amplitude is within 3dB over the entire range and the phase at crossover points is within approximately 3 degrees as you can see.

 

Edited July 30, 20187 yr by Ittaku

i've checked out the pricing of the Dspeaker XO you use....no wonder they sound great already lol

3 minutes ago, Happy said:

i've checked out the pricing of the Dspeaker XO you use....no wonder they sound great already lol

Indeed it is their reference DAC/XO, but then the DAVE does cost almost 4x as much and isn't a XO or do DSP room correction...

3 minutes ago, Ittaku said:

Indeed it is their reference DAC/XO, but then the DAVE does cost almost 4x as much and isn't a XO or do DSP room correction...

i believe XO and DSP per se affect the SQ far, far more than the precision of a DA converter which usually is pretty good these days.

 

Quote

phase at crossover points is within approximately 3 degrees as you can see.

30 ?

 

Quote

By the way, here are the calculated system response and phase graphs of the actual driver response with the actual used crossover components for those interested

This is a v. nice looking axial response...          I assume these are 'anechoic' type conditions. eg. outside, with ground place, or elevated, or something.... or nearfield convolved with the cabinet diffraction?    (Hard to interpret without knowing more info like this).

 

Do you tilt it for listening (eg. little more bass, less treble)?

Do you have data for the polar response?

 

 

Assuming you lifted them off the ground, I feel your pain  ?  .... cos this shot of mine was barely enough to get data on the H frame cavity.     https://www.stereo.net.au/forums/uploads/monthly_08_2013/post-108814-0-55197900-1377951179_thumb.jpg

 

gee im glad im not into measuring things:

 

3 minutes ago, Happy said:

gee im glad im not into measuring things

Lest anyone is scared off... what you see there is only something which needs to be done when designing a speaker.

9 minutes ago, davewantsmoore said:

30 ?

My highlight:

2 hours ago, Ittaku said:

the phase at crossover points is within approximately 3 degrees

The crossover points are 230 and 2500 Hz.

 

10 minutes ago, davewantsmoore said:

This is a v. nice looking axial response...   

Woaaah I wish this was an actual axial response. That plot you're looking at is the electrical design part only based on the components going into the design and the plots of drivers in free air based on the manufacturer's data. I gave an axial response in room earlier on this thread and of course it's nowhere near that good lol. Here is the actual in-room plot at my listening position, and bear in mind DSP room correction and subwoofer!

 

12 minutes ago, davewantsmoore said:

Lest anyone is scared off... what you see there is only something which needs to be done when designing a speaker.

the speaker on display is reasonably ok size btw.

i have no intention of doing the same with my horns and i live on the 5th floor unit.....

1 hour ago, Ittaku said:

My highlight:

The crossover points are 230 and 2500 Hz.

Yeah, sure, I understand  (and can read the crossover points from the chart, obviously).   The phase reads ~25 degrees at these frequencies.

 

1 hour ago, Ittaku said:

plots of drivers in free air based on the manufacturer's data.

Thanks.  Yes, I understood it was a "simulation" of the filters with the driver data .... but just not where the driver data came from.

 

You could make it "that good" with EQ .... but single points in space like that aren't so representative, so it's doesn't really matter.

 

 

1 hour ago, Happy said:

the speaker on display is reasonably ok size btw.

i have no intention of doing the same with my horns and i live on the 5th floor unit.....

It is about 120cm high.

 

It was actually easier to do this with a (huge 90cmx60cm) horn ... because they only played down to ~200Hz, and they only fire in one direction.

 

A dipole is much harder to measure through 100Hz to 1000Hz

Edited July 30, 20187 yr by davewantsmoore

21 minutes ago, davewantsmoore said:

Yeah, sure, I understand  (and can read the crossover points from the chart, obviously).   The phase reads ~25 degrees at these frequencies.

Oh right, my bad; looked at wrong legend ?

2 hours ago, Happy said:

gee im glad im not into measuring things:

 

 

You have these, H???

 

Andy

 

 
You have these, H???
 
Andy
 

He's quoting from Dave's post.

20 minutes ago, Ittaku said:

24 minutes ago, andyr said:

 
You have these, H???
 
Andy
 

He's quoting from Dave's post.

 

Aah, thanks, Con.  Yes, that makes more sense! 

 

Andy

Meh, moving the resistor going to the midranges to after the crossover brings the phases closer to each other at the crossover points, but at the cost of some more bumpiness in the curve. My original crossover calculations didn't include a resistor and the effect of the resistor on phase was more dramatic than I'd have expected.

 

Guess I'll switch it around tomorrow and see how it sounds. Wish I didn't need a resistor at all... will see how things change with the two woofers planned for the future, and perhaps redesign the midrange with the resistor included next time.

 

Edited July 30, 20187 yr by Ittaku

What is the pink line?

 

It appears to be the "power response".    This is different to the typical summed driver response.   A correctly summing in-phase crossover (unless the drivers are coincident) will have a notch in the power response at the crossover frequency  (the driver power will sum to +3dB instead of +6dB)

 

2 minutes ago, davewantsmoore said:

What is the pink line?

Yes it's the power response.

Here's the summed response with resistor before crossover:

 

And with resistor after crossover:

 

Crossover frequency changed a bit on the midrange, not surprisingly given change in impedance the crossover components are seeing.

Edited July 30, 20187 yr by Ittaku

10 minutes ago, Ittaku said:

Yes it's the power response.

So, it should not be flat through the cross region.

 

EDIT:  You've posted the summed response now  ?

 

9 hours ago, Ittaku said:

Meh, moving the resistor going to the midranges to after the crossover brings the phases closer to each other at the crossover points

 

Yes... but if you look at the phase curves, they are actually "worse", because the slope of the phase curves have becomes less similar.... and so they don't sum through the region where both the drivers play,

 

If you look at the first chart, for example .... the phase curves are more the same overall slope, just shifted to the right/left of each other.    eg. if you shifted the woofer back in time (left), and the tweeter forward (right) then they would overlap over a bigger range.

Edited July 30, 20187 yr by davewantsmoore

1 minute ago, davewantsmoore said:

This would be flat through the crossover regions, and the drivers summing to +6dB at the XO frequency.

Linkwitz Riley should not be summing to a peak.

2 minutes ago, davewantsmoore said:

Yes... but if you look at the phase curves, they are actually "worse", because the slope of the phase curves have becomes less similar.

And we've already argued about what's more important and disagreed.

2 minutes ago, Ittaku said:

Linkwitz Riley should not be summing to a peak.

I'm not quite sure what you mean by this comment.

 

For an in-phase crossover .... two drivers at each -6dB, will sum to +6dB.    If you look at the power response, they will only sum to +3dB .... and this will look like a +3dB "notch" at the XO frequency.

Edited July 30, 20187 yr by davewantsmoore

2 minutes ago, davewantsmoore said:

I'm not quite sure what you mean by this comment.

 

For an in-phase crossover .... two drivers at each -6dB, will sum to +6dB.    If you look at the power response, they will only sum to +3dB .... and this will look like a +3dB "notch" at the XO frequency.

I'm referring to this.

5 minutes ago, Ittaku said:

I'm referring to this.

Sure.   Your in phase drivers (eg. LR2 in that chart) will sum to +6dB

 

If you mean, why don't your drivers don't sum to a beautifully flat line through the XO region? .... it is that the driver responses are not quite the right shape, and they are not in-phase through the XO region.

13 minutes ago, davewantsmoore said:

Sure.   Your in phase drivers (eg. LR2 in that chart) will sum to +6dB

 

If you mean, why don't your drivers don't sum to a beautifully flat line through the XO region? .... it is that the driver responses are not quite the right shape, and they are not in-phase through the XO region.

No, I wasn't asking that. You were the one saying it should be +6. Where's the +6?