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Discussion Starter · #1 ·
I am using REW and an FBQ2496. I transmit filters via midi and every filter has to then be manually adjusted because they are usually off by several digits... (only the frequencies). Does anyone have any idea why I am experiencing this?
 

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I am using REW and an FBQ2496. I transmit filters via midi and every filter has to then be manually adjusted because they are usually off by several digits... (only the frequencies). Does anyone have any idea why I am experiencing this?
- There were some special ( exceptional ) circumstances where the frequencies generated ( by REWs function generator ) were off-set downwards ( @ 8% ) to the intended freq. .
- I thought that this fault was fixed ( or was attributed to "resampling" issues ) .

- OTOH,( + IME ) this is quite reproducible ( on a very marginal/unstable setup that can't actually measure & produce a proper IR ).

- For instance, if I run a loop-back cable ( output to input ) and then send ( say a 1K tone ) into the RTA for analysis , I'll measure 917 hz .
- This is with either REW 5.0 & ( 5.01 beta ) running on a PPC MacMini running OS 10.5.8 ( & "SoundFlower" for input ) .

- FWIW, ( I don't believe any flavour of REW is supposed to actually work properly on this PPC computer ).

- Nothing like this happens in my main setup ( XP pro SP3 ) .

- What are the details of your setup ? ( computer, OS platform & version, soundcard ,version of REW, etc. etc. )

- ( Several digits "off" means/translates into just what frequency exactly ) ?

:sn:
 

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Discussion Starter · #3 ·
I am running windows 7 with an RME HDSP 9652 and pretty much every frequency that is sent via midi has to be adjusted upward to match the REW filters, there are occasions when one of 10 or more filters is right, but the rest will be off...and its not a repeatable percentage, they are all different.43.25 hz = 42.2 hz 133.7 hz = 129 etc.... some dont amount to much of a difference, but they're all different.
 

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Midi transmission to the FBQ can be unreliable, for no obvious reason - the BFD proved far more reliable, unless it had the V1.3 firmware version that kills midi transfer altogether. There is a setting in the REW comms preferences (FBQ message delay) which may help, worth trying different settings to see if it does. The frequencies sent to the FBQ are in two parts, a 'coarse' setting and a 'fine' adjustment (the BFD used a similar coarse/fine scheme) so there are two opportunities for errors in frequency, but problems can appear in the gain or bandwidth also.
 
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