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Acoustic timing --- delay question --- problem

1681 Views 4 Replies 2 Participants Last post by  Wolke
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Hello,

My first measurement over *Use acoustic timing reference* with HDMI and ASIO4ALL makes problem or I do not understand something here.

I have to measure here in Stereo without RIGHT speaker or direct LFE, in Stereo i have delay time from 100ms. What is OK, see the files thank you.


Here the setup for ASIO4ALL:

First Test: delay very high

Sub 1 measurement:
REW output: right channel
Right channel speaker muted or disconnected
REW acoustic timing reference: left channel
All subs muted except sub 1


Second Test: delay OK???

Sub 1 measurement:
REW output: ***LFE channel***
REW acoustic timing reference: left channel
All subs muted except sub 1

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In your mdat file the left (delay 0), right (delay 0.17 ms) and LFE (delay 7.15ms) measurements all looked normal, though the LFE measurement has low signal to noise (noise floor is only 30 dB down). The 'SUB' measurement has only 15 dB signal to noise, not enough to get a reliable measurement. Is that sub far from the mic? Increasing the measurement level a little might help.
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Hello JohnM,

thank you for your prompt reply and info.
I will then measure again with higher level and then report here.

Then I have an understanding question how does the program on this value for the LFE 7,15ms in the diagram I see about 33,8ms...???
Where can i find the right value?
This is a very nice program and I want to understand everything correctly, thank you.

Here the picture for the timing... is from the file in the last post Timing Delay.mdat

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If the peak of the measurement is more than 1 ms after the start (defined as the first point the response rises above 10% of the peak level) REW assumes the measurement is of a band limited device and uses the start point instead of the peak for its delay calculation.
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Ok,
I understood that very well :)

And here the new measurement with higher level...
Reference Output 1, Left channel.
So I have delay 12,42ms with bassmanagement (Output 2, right channel disconnected) and 3,96ms with LFE (Output 4, for LFE).*SUB.jpg*
Is it OK, and why is here the timing differently, is it the bassmanagemant delay, I think.
The AV-Receiver Onkyo TX-NR646 was in Multichannel without AccuEQ for all measurement (Input HDMI).

Then I found that my Receiver will calculate the distance with 300m/s show *LEFT and Right.jpg* here I set the distance from the right speaker on *0m* the Left Speaker has 2,7m like the right one.

So 2.7m is actually 3.1??!!
I measured 2.95 from the mic to speaker chassis!
My speakers are Klipsch, I have to measure up to the horn ???
From the Horn Outside to the tweeter are about 0,07m.. is very difficult.
Sorry for the complicated questions :)

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