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Discussion Starter · #1 ·
Hi All,

I was taking some high level sweeps of my subwoofer yesterday and ran into a problem. At the beginning of each sweep, I was getting a pop or thud noise. At lower levels it was not an issue but when I hit over 105 dB at the LP it causes my clipping protection to engage on my Crown XLS1000.

Now, I don't believe this is a gain setting issue. After the pop happens and the clip protection has done it's thing, the measurement continues just fine at the higher level with no compression or clipping. I just don't get any data below about 30Hz because of the amp protection. Also, I know I've run sine waves at higher levels without clipping problems.

Any suggestions of how to eliminate this basically DC pop or thud?

Here is my equipment:

UMIK-1 calibrated by CSL
HTPC running Windows 7
Nvidia GTX 560 with HDMI out
HDMI in to Onkyo TX-NR809
Subwoofer out to Crown XLS1000 via RCA-XLR

Thanks,

Vann
 

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Can you change the output of REW to match your playback device in windows (e.g. 48kHz, 16b)? Maybe the pop is from a reconfiguration of the sound codec in your 560.
 

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Discussion Starter · #4 ·
Hmm, my windows sound says its configured for 16-bit 48 khz and REW is at 48 khz
 

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Hi All,

I was taking some high level sweeps of my subwoofer yesterday and ran into a problem. At the beginning of each sweep, I was getting a pop or thud noise. At lower levels it was not an issue but when I hit over 105 dB at the LP it causes my clipping protection to engage on my Crown XLS1000.



Vann
Are you making a sweep at 105 db,85 db is better.
Maybe you make it clip because of the high volume level
 

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Discussion Starter · #6 ·
Thank you but the sweep is not to determine frequency response at nominal level. I'm attempting to find the maximum clean SPL of the system.

I also do not believe I am clipping due to amp gain. There is a noticeable "pop" that happens at the start of the sweep that prematurely clips my amp.
 

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Discussion Starter · #7 ·
I don't think I'm using ASIO. Perhaps I should be. I'll have to check this tonight when I get home.
 

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Discussion Starter · #8 ·
Tonight I tried ASIO. Seems like it may have fixed the popping noise issue but I was unable to take any high level sweeps to confirm. It will likely be the end of the week before I can do so...
 

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I noticed that within J River that there is a Pause that can be initiated before any audio is sent from the HTPC to your Onkyo. I wonder if there is such a setting within REW.
 
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