Linesource measurements and xoverbuilding

[temp25]

Do you have a single woofer zma? Edit.. I guess porting has changed it some. Porting may or may not be optimum, but that's one of many design choices. So, don't worry about posting a new zma. It is what it is.

 

[temp25]

I struggled for a while trying to keep speaker impedance at 4 ohms minimum. I think I have resolved that issue.

 

[jawen]

The Data in post 33 is interesting but it doesn't show what happens if we cut the bass drivers out of the overall picture

Do you mean to also cut the 4 midranges from playing 250 hz and downwards?

how do you feel about the current sound. As suggested maybe it is worth doing an average over the listening area which is the TV sofa. Maybe the area where you were thinking you needed a notch filter at 1.2KHz how does that look in separate measurement's across the width of the sofa. Is it hot directly on axis, but isn't there on the ends of the sofa ?

It sounds real good, and i now have a little toe-out on the nearest speaker (right one)
So spl perceived equally ( i sitt to the right in my sofa, near computer)

I have 2 different xovers on left and right speaker.
Left speaker have a notch at ca 1200 hz, and some other small changes

 

[temp25]

Do you cross at 80hz to the sub?

 

[raymondj]

Do you mean to also cut the 4 midranges from playing 250 hz and downwards?

No just the bass section.

Good to hear that you are getting a decent sound. Just ultra fine tuning now.

 

[jawen]

Do you have a single woofer zma? Edit.. I guess porting has changed it some. Porting may or may not be optimum, but that's one of many design choices. So, don't worry about posting a new zma. It is what it is.

i have solder the woofers in serie inside with a short cable between possetive and then negative on the 2:e woffer.
So hard to do that, BUT not impossible if i unmont a woofer and solder it 8 ohm (with the woofer beside it "dead")

 

[jawen]

No just the bass section

Isen´t the bass section allready there at around 250 hz ?

 

[temp25]

Here's what he is asking. This uses the bigger coil.

 

[temp25]

i have solder the woofers in serie inside with a short cable between possetive and then negative on the 2:e woffer.
So hard to do that, BUT not impossible if i unmont a woofer and solder it 8 ohm (with the woofer beside it "dead")

Don't need the measurement, so don't attempt. At this point,just assume you have good data.

 

[jawen]

Do you cross at 80hz to the sub?

Can be 100-250 hz 🙂
At the time around 200 hz

 

[temp25]

That probably changes the ideal filter, but here's the one I was working on. Try this filter in your sim. I can also show you one where the woofers go up higher. If you cross to the sub at 200hz there's not much being played by the outer woofers using this filter. It really becomes subjective.

 

[raymondj]

I do believe we were at cross purposes.

You are rolling them in at 250Hz, I was asking to roll them off at 250Hz, I had forgotten that you had subwoofers as part of the mix.

Good luck with the final tweaking.

 

[jawen]

That probably changes the ideal filter, but here's the one I was working on. Try this filter in your sim. I can also show you one where the woofers go up higher. If you cross to the sub at 200hz there's not much being played by the outer woofers using this filter. It really becomes subjective.

I will simulate you values 👍

Just take 2 measurement from my sofa on left speaker, mic at ca 2 meter 1/3 up on speakers hight.
So mic is around the lowest midrange above the 2 lower woffers.

Tweeter in phase and out of phase

 

[temp25]

Can you convert measurements to gated? I use REW to measure, and it's easy to do, after the measurement has been made ,in that software.

The one time I used non-gated measurements for x-over work, I did not like the results.

 

[jawen]

When i raise the mic ca 20 cm, upp to around 2 midrange under tweeter, it looks like this

 

[jawen]

Can you convert measurements to gated?

Is this "Gated" ?

 

[temp25]

It's hard for me to tell, but if I interpret those measurements, it seems like the ideal listening axis is closer to the second measurement.

 

[temp25]

Can you show me gated measurements? That would be just the speaker, and without reflections. However, since the speaker is near the floor,they may be a mess anyway.

 

[temp25]

Is this "Gated" ?

Yes it is. Can you gate lower. Maybe to 300hz, instead of 500hz? The response will just stop below 300hz. The lower you can go, the better, but room reflections will limit how low.

 

[jawen]

And this (mic 15 cm higher)