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Post by newgolf on Jul 17, 2024 7:34:09 GMT -5
Hello guys, I have a query that may have already been answered if so I apologize, before passing Dirac I adjust the phase with the boxes, because once Dirac has passed and I measure again I see that the sub has been put against phase having to change the phase again, and if I pass Dirac again with that phase that is to say without touching anything it changes it again, is this normal? Thank you
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Post by marcl on Jul 17, 2024 7:39:11 GMT -5
Hello guys, I have a query that may have already been answered if so I apologize, before passing Dirac I adjust the phase with the boxes, because once Dirac has passed and I measure again I see that the sub has been put against phase having to change the phase again, and if I pass Dirac again with that phase that is to say without touching anything it changes it again, is this normal? Thank you Dirac looks at the polarity of all of the speakers including the subs. If it thinks a speaker/sub is not the same as the others it will flip the polarity. This is normal and should represent the correct polarity for all the speakers/subs. You can see the results in the Impulse Response view in Filter Design. You should see the corrected polarity of all speakers/subs matching a positive polarity |
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KeithL
Administrator 
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Post by KeithL on Jul 17, 2024 9:18:38 GMT -5
There's something worth mentioning here...
When you measure sound arriving at the listening position...
Or when room correction software measures it...
You are measuring the ACOUSTIC phase of the actual sound reaching that location through the air.
This MAY not be the same as the electrical phase at the speaker connection itself.
The speaker itself may introduce a phase shift internally or between its drivers...
And the delay caused by the time it takes the sound to reach the microphone from the speaker does as well...
Here's a simple example:
Let's say you play the same 1 kH tone from a pair of identical speakers...
The speakers are the exact same distance from your head and the sound from both is exactly in phase...
Now move one of those speakers six inches further away from the microphone...
Those two speakers will now be EXACTLY OUT OF PHASE at 1 kHz at the microphone (your listening position).
(The time it takes sound to travel six inches will cause a phase difference of approximately 180 degrees at 1 kHz.)
This is the sort of thing that room correction is designed to detect, measure, and correct.
Subwoofers operate at much lower frequencies, with much longer wavelengths, which are much less critical of minute differences in distance.
However the same principle holds true...
This is why, if your room correction software reports that "a speaker appears to be out of phase"...
You should check your wiring and such...
But, once you've verified that everything is hooked up correctly, you should probably assume that the software is right - and let it make its correction.
(Mistakes do happen - so you should always listen to the results too - but there's a good chance the software actually detected something and corrected it appropriately.)
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Post by marcl on Jul 17, 2024 9:39:19 GMT -5
There's something worth mentioning here... When you measure sound arriving at the listening position... Or when room correction software measures it... You are measuring the ACOUSTIC phase of the actual sound reaching that location through the air. This MAY not be the same as the electrical phase at the speaker connection itself. The speaker itself may introduce a phase shift internally or between its drivers... And the delay caused by the time it takes the sound to reach the microphone from the speaker does as well... Here's a simple example: Let's say you play the same 1 kH tone from a pair of identical speakers... The speakers are the exact same distance from your head and the sound from both is exactly in phase... Now move one of those speakers six inches further away from the microphone... Those two speakers will now be EXACTLY OUT OF PHASE at 1 kHz at the microphone (your listening position). (The time it takes sound to travel six inches will cause a phase difference of approximately 180 degrees at 1 kHz.) This is the sort of thing that room correction is designed to detect, measure, and correct. Subwoofers operate at much lower frequencies, with much longer wavelengths, which are much less critical of minute differences in distance. However the same principle holds true... This is why, if your room correction software reports that "a speaker appears to be out of phase"... You should check your wiring and such... But, once you've verified that everything is hooked up correctly, you should probably assume that the software is right - and let it make its correction. (Mistakes do happen - so you should always listen to the results too - but there's a good chance the software actually detected something and corrected it appropriately.) And so here's a case where we should distinguish between phase and polarity, right? When Dirac looks at the impulse responses of the measured speakers, it's only looking at polarity ... does the wave at time=0 rise for all the speakers. If you physically switch the wires on one of the speakers, Dirac will see the wave go the opposite way ... opposite polarity ... and Dirac will fix it. This is how Dirac sees my sub, and how it corrected the impulse response but did not flip polarity.  |
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Post by foggy1956 on Jul 17, 2024 11:24:34 GMT -5
There's something worth mentioning here... When you measure sound arriving at the listening position... Or when room correction software measures it... You are measuring the ACOUSTIC phase of the actual sound reaching that location through the air. This MAY not be the same as the electrical phase at the speaker connection itself. The speaker itself may introduce a phase shift internally or between its drivers... And the delay caused by the time it takes the sound to reach the microphone from the speaker does as well... Here's a simple example: Let's say you play the same 1 kH tone from a pair of identical speakers... The speakers are the exact same distance from your head and the sound from both is exactly in phase... Now move one of those speakers six inches further away from the microphone... Those two speakers will now be EXACTLY OUT OF PHASE at 1 kHz at the microphone (your listening position). (The time it takes sound to travel six inches will cause a phase difference of approximately 180 degrees at 1 kHz.) This is the sort of thing that room correction is designed to detect, measure, and correct. Subwoofers operate at much lower frequencies, with much longer wavelengths, which are much less critical of minute differences in distance. However the same principle holds true... This is why, if your room correction software reports that "a speaker appears to be out of phase"... You should check your wiring and such... But, once you've verified that everything is hooked up correctly, you should probably assume that the software is right - and let it make its correction. (Mistakes do happen - so you should always listen to the results too - but there's a good chance the software actually detected something and corrected it appropriately.) And so here's a case where we should distinguish between phase and polarity, right? When Dirac looks at the impulse responses of the measured speakers, it's only looking at polarity ... does the wave at time=0 rise for all the speakers. If you physically switch the wires on one of the speakers, Dirac will see the wave go the opposite way ... opposite polarity ... and Dirac will fix it. This is how Dirac sees my sub, and how it corrected the impulse response but did not flip polarity. View AttachmentIs it important at this point to mention that users of Emotiva amps with a mix of RCA and XLR connections need to flip the polarity of a group of speakers if I remember correctly? |
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Post by 405x5 on Jul 17, 2024 13:26:02 GMT -5
…… It is also worth mentioning, That In some instances, it is not a crime to MANUALLY, Flip the phase switch (if so equipped ) at each of the subs, selecting whichever position in concert with everything else in the room provides the most satisfactory bass response.  Last time I checked, no End user ever got arrested for trying such a thing.…… Don’t be afraid! |
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Post by newgolf on Jul 17, 2024 13:26:34 GMT -5
Hay algo que vale la pena mencionar aquí... Cuando mides el sonido que llega a la posición de escucha... O cuando el software de corrección de la habitación lo mide... Estás midiendo la fase ACÚSTICA del sonido real que llega a esa ubicación a través del aire. Este PUEDE no ser lo mismo que la fase eléctrica en la conexión del altavoz. El propio altavoz en sí puede introducir un cambio de fase internamente o entre sus controladores... Y el retraso causado por el tiempo que tarda el sonido en llegar al micrófono desde el altavoz también lo hace... Aquí hay un ejemplo simple: Digamos que reproduces el mismo los altavoces están exactamente a la misma distancia de su cabeza y el sonido de ambos está exactamente en fase... Ahora mueva uno de esos altavoces a seis pulgadas más lejos del micrófono... Esos dos altavoces ahora estarán EXACTAMENTE FUERA DE FASE a 1 kHz en el micrófono (su posición de escucha). (El tiempo que tarda el sonido en viajar seis pulgadas causará una diferencia de fase de aproximadamente 180 grados a 1 kHz.) Este es el tipo de cosas que la corrección de la habitación está diseñada para detectar, medir y corregir. Los subwoofers operan a frecuencias mucho más bajas, con longitudes de onda mucho más largas, que son mucho menos críticas con las diferencias de minutos en distancia. Sin embargo, el mismo principio es cierto... Es por eso que, si su software de corrección de habitación informa que "un altavoz parece estar fuera de fase"... Debe comprobar su cableado y demás... Pero, una vez que haya verificado que todo está conectado correctamente, probablemente debe asumir que el software es correcto, y dejar que haga su corrección. (Los errores ocurren, por lo que siempre debe escuchar los resultados también, pero hay una buena posibilidad de que el software realmente detecte algo y lo corrija adecuadamente.) could be this, since I have the rear monitors against phase since they are dipolar, otherwise the impulse would coincide with the front ones. Thank you |
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Post by newgolf on Jul 17, 2024 13:28:23 GMT -5
Hola chicos, tengo una pregunta que ya ha sido respondida, si es así, me disculpo, antes de pasar Dirac, ajusto la fase con las cajas, porque una vez que Dirac ha pasado y mido de nuevo, veo que el sub se ha puesto en contra de la fase que tiene que cambiar la fase de nuevo, y si paso Dirac de nuevo con esa fase, es decir, sin tocar nada, lo cambia de nuevo, ¿es esto normal? Gracias[/cita]Dirac analiza la polaridad de todos los altavoces, incluidos los subs. Si piensa que un altavoz/sub no es el mismo que los demás, cambiará la polaridad. Esto es normal y debería representar la polaridad correcta para todos los altavoces/subs. Puedes ver los resultados en la vista de respuesta de impulso en el diseño del filtro. Deberías ver la polaridad corregida de todos los altavoces/subs que coinciden con una polaridad positiva could be this, since I have the rear monitors against phase since they are dipolar, otherwise the impulse would coincide with the front ones. Thank you |
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Post by foggy1956 on Jul 17, 2024 15:20:05 GMT -5
…… It is also worth mentioning, That In some instances, it is not a crime to MANUALLY, Flip the polarity at each of the subs, selecting whichever position in concert with everything else in the room provides the most satisfactory bass response. Last time I checked, no End user ever got arrested for trying such a thing.…… Don’t be afraid! Do you flip the switch on the sub with XLR connected amps or RCA? |
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