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Phase trace

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Timo Beckman:
The method is valid . The only thing i can see is a problem @ about 100Hz .
You can see the jump in the phase trace @ about 100Hz .
What's your x-over point and the filters being used ?
You can see wich speaker needs delay by looking at the angles of the phase trace . If the top has a less steeper angle than the subs the top needs delay and vice versa .
After aligning the angles of the tf sub and top you might find that you need to reverse polarity .

Adam Black:

--- Quote from: Paul Tucci on October 26, 2011, 10:52:01 PM ---how did you get that pretty orange band on the top?
--- End quote ---

The orange cursor readout area indicates that it's the demo build.

Johnny Diaz:

--- Quote from: Timo Beckman on October 27, 2011, 03:54:30 AM ---The method is valid . The only thing i can see is a problem @ about 100Hz .
You can see the jump in the phase trace @ about 100Hz .
What's your x-over point and the filters being used ?
You can see wich speaker needs delay by looking at the angles of the phase trace . If the top has a less steeper angle than the subs the top needs delay and vice versa .
After aligning the angles of the tf sub and top you might find that you need to reverse polarity .

--- End quote ---

Timo,

I have the top's hipass at 45Hz, lopass at 20khz with bw24 slope and the sub's hipass at 45hz, lopass at 88hz with bw24.  I forgot of change the tops hipass to 88hz.  I will do that soon and report back. 

Since I will have the hipass on top's at 80hz should I discard data below 80hz and vice versa?  Also, I have the subs lopass at 88hz bw24 but Smaart is still showing me data in the phase trace well above 88hz like in the 2k-4k region.  How is it getting this data?

Johnny

Johnny Diaz:

--- Quote from: Adam Black on October 27, 2011, 09:27:07 AM ---The orange cursor readout area indicates that it's the demo build.

--- End quote ---

Yup I have the demo installed.  Saving up to purchase. 

Timo Beckman:

--- Quote from: Johnny Diaz on October 27, 2011, 12:52:34 PM ---Timo,

I have the top's hipass at 45Hz, lopass at 20khz with bw24 slope and the sub's hipass at 45hz, lopass at 88hz with bw24.  I forgot of change the tops hipass to 88hz.  I will do that soon and report back. 

Since I will have the hipass on top's at 80hz should I discard data below 80hz and vice versa?  Also, I have the subs lopass at 88hz bw24 but Smaart is still showing me data in the phase trace well above 88hz like in the 2k-4k region.  How is it getting this data?

Johnny

--- End quote ---

If you take a look at the frequency response of the top (solo) you should be able to see the roll off of the top (without the high-pass filter) . What you should look for is the point where it drops -6db . A wild gues about 125Hz . If you put a 24 db filter @ that frequency that becomes the low-pass frequency for the sub . The 24db/oct filter @ 125Hz means that at about 63Hz the level has dropped with 24db . If you get the phase traces of them both to overlap at a large area around the x-over point you get addition and more headroom . Because of the level your using on the sub The overlap zone is larger so you need to check from 60 to about 150 Hz .
You can see the bump @ 100Hz in the phase & frequency response wich is a indication that a 180dg phase difference excists between the top and sub at that point .

2nd Watchout using butterworth filters . If you put that filter in to use at 125Hz the -6db point is not at 125Hz but at a different point and the addition of the filter combination at 125Hz is not 0db but a littlebit more . If you want to go for flat reponse and at the frequency you set as the x-over point you need to use Linkwitz rilley 24 db/oct .

You might try with less steeper filters so 12 or 18db/oct but they have there own carracteristics .

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