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Multi-Way Conventional loudspeakers with crossovers

rePhase, a loudspeaker phase linearization, EQ and FIR filtering tool
rePhase, a loudspeaker phase linearization, EQ and FIR filtering tool
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Old 10th August 2019, 06:56 PM   #2741
Oabeieo is offline Oabeieo  United States
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Location: Denver
Quote:
Originally Posted by torgeirs View Post
This is very interesting:-)
Can you draw a picture of this setup with responces and corrections?
signal - rew - amp - 2"
- rew - amp - 8"

As I understand it the 2" is cancelling the reflections at about 800Hz?

Maybe in an own thread. I know it is a lot of work, but the solution is fantastic!
Yeah Iíll do a separate thread in the car audio section
And not clutter this fine thread.

When I get stumped this thread has the the right ppl to help me get on track

Itís not a cure all , but definitely takes the edge off. It works surprisingly good, but also has its own little issues that are a way better trade off

I reduced the power going to the 2Ē and that seems to work the best. I also added some very aggressive compression as well. But basically just took the difference of the 8 in and out of the pod. Averaged the two and inverted it.
I also built linear phase crossovers for the 2Ē and band limited them to 600-1k
48db slopes. I only wanted to target the modal midrange where I was having issues and the 2Ē was worthless under 600 and seemed to cause more issues that Iím not smart enough to deal with. The 2Ē just barely barely playing stops the issue, the more power I put on it the more the other issues came up.
So itís in a happy place now (I think) ;-)

Thatís where I stared as the response to the 2Ē and that alone worked pretty good , Iím sure it could be better but for a guess it did what I wanted so hey....canít argue with results.
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Old 11th August 2019, 03:28 PM   #2742
torgeirs is offline torgeirs  Norway
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Super!
600Hz to 1k is 34cm to 57 cm wavelength so 2" is not directive in that erea.
So maybe that explains why it is working so well.
And of cource you need the very good phase control that REW provides.
A comparition is noice cancelling headphones, and we all know they work! (With some ekstra work put into it because the canselling is done with the same speakercone as the signal:-))

Last edited by torgeirs; 11th August 2019 at 03:33 PM.
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Old 13th August 2019, 10:23 AM   #2743
mpa is offline mpa  United Kingdom
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A question for the Rephase experts! Can anyone explain why I get exactly half the latency in Rephase than I do in fir Designer for the exact same number of taps at the same sample rate??
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Old 13th August 2019, 12:29 PM   #2744
mark100 is offline mark100  United States
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Quote:
Originally Posted by mpa View Post
A question for the Rephase experts! Can anyone explain why I get exactly half the latency in Rephase than I do in fir Designer for the exact same number of taps at the same sample rate??
Check where impulse centering is...
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Old 14th August 2019, 10:23 AM   #2745
mpa is offline mpa  United Kingdom
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Originally Posted by mark100 View Post
Check where impulse centering is...
Thanks for the tip! Even with the exact same centering as fir Designer Rephase
still shows slightly less latency though.
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Old 14th August 2019, 01:31 PM   #2746
mark100 is offline mark100  United States
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Quote:
Originally Posted by mpa View Post
Thanks for the tip! Even with the exact same centering as fir Designer Rephase
still shows slightly less latency though.
Glad it helped !

How much less latency?
Are you letting both programs determine centering?
Oh, and did you use Find Peak in FirD?
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Old 28th August 2019, 07:25 PM   #2747
Oabeieo is offline Oabeieo  United States
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Is it possible to do 48db slopes and make it linear
With a bandwidth of 30hz?


I have some 10s in sealed boxes with a high QTC (1.1) that I want to play from 65-95hz only

Thanks in advance
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Old 28th August 2019, 10:02 PM   #2748
pos is offline pos  Europe
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dB/oct slopes are defined on a logarithm frequency scale: you get 48dB of attenuation on an octave, ie doubling (for a low-pass) or halving (for a high-pass) the frequency.
Getting a given attenuation on a 30Hz bandwidth will not call for the same dB/oct slope at 100Hz as it will at 1kHz for example.

In your case, assuming that box is not crossed over to a sub, what you could do is to first compensate the existing high-pass of the box/driver using a high-pass filter in "compensate" mode in the minimum-phase filter tab to get flat-ish magnitude and phase curves, and then apply whatever linear-phase high-pass you want, with the slope you need.
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2019-01-16: rePhase 1.4.3
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Old 29th August 2019, 01:17 AM   #2749
Oabeieo is offline Oabeieo  United States
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Quote:
Originally Posted by pos View Post
dB/oct slopes are defined on a logarithm frequency scale: you get 48dB of attenuation on an octave, ie doubling (for a low-pass) or halving (for a high-pass) the frequency.
Getting a given attenuation on a 30Hz bandwidth will not call for the same dB/oct slope at 100Hz as it will at 1kHz for example.

In your case, assuming that box is not crossed over to a sub, what you could do is to first compensate the existing high-pass of the box/driver using a high-pass filter in "compensate" mode in the minimum-phase filter tab to get flat-ish magnitude and phase curves, and then apply whatever linear-phase high-pass you want, with the slope you need.

Thank you pos!

Yeah not crossed to a sub that is correct. It is just for reinforcement only and with some timing tricks move some of the room modes around or get better reinforcement from the mains.

I don’t like the sound of brute force to fill a hole , I do like multiple drivers with the right timing tricks to reinforce hard room modes.

I just wasn’t sure if the narrow bandwidth will mess with the way the fir linearization is done or not...


Yes I do understand what you mean also like a 6bdBW at 25hz is like a LR4 at 100hz etc for example. So this makes sense on why you brought it up like that.

And the LP side i can just add the linearization filter on top of my minimum phase filter,

Once the compensation is done on the HP side it should work normally I would imagine...?


Okay! Yes I will defytry that approach, it makes good sense and I see what your getting at now.

You guys are the best!

Last edited by Oabeieo; 29th August 2019 at 01:22 AM.
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Old 29th August 2019, 01:28 AM   #2750
Oabeieo is offline Oabeieo  United States
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Yes the high QTC rolls off very fast , the compensate seems to work!
Wow it sound good! Very pleased. Thank you sir! Can’t even tell it’s playing or where speakers are located (under back seat car)
Just have the hole filled in nicely and mains sound the same.
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