So, in order to keep this from getting buried in its original thread ("Inside out (comb-filtering) Sound") I just posted the recordings from my 990, made using the FRONT and Zone 2 outputs. The files are available in 320 kbps mp3 as well as FLAC formats; you can download these at will. I personally can't hear a difference in these files between the FLAC and the 320 kbps mp3's, but I thought that I would post them in FLAC (which is fully lossless and can be reconstructed to its parent wav file) if anyone thought the issue might be attributable to the mp3 encoding process (it's not).

Also, to show (graphically) the comb-filtering, I have posted the .jpg files (that show the spectra observed for the front and zone 2 ouputs for STEREO, BYPASS, and UPSAMPLE modes) to my FTP site so that they can be downloaded.

However, I also know that listening to the files will make it obvious why I see this as an issue, and why I'd like to know if other users are experiencing this; as you compare the FRONT files (all of which have the comb-filtering issue) you will hear that the BYPASS and STEREO mode-derived recordings sound very much alike, but you will note a difference in timbre when you listen to the UPSAMPLE-derived version. Compare the Zone 2 outputs to one another and you'll see they basically are identical-sounding, and all are free of the comb-filtering observed in the front outputs. So...the 'good news' is that my whole-house feed doesn't suffer from this issue...but the 'bad news' is that the system in my main listening room does.

If you want to check whether or not your 990 is doing this, please revisit the thread ("Inside out sound") and if you still have questions, just email me (my address is in my profile); I can post some white noise files if you like / need, or I could send one via email.

Anyway, once you log on (credentials are below) you will see that there are three folders - one for each mode BYPASS, one for STEREO, and one for UPSAMPLE. Each houses the jpg's, mp3's and .flac files that document the issue. I have the data from the otehr modes that I tested, and I may post those should there be interest from the Readers.

If you are using an FTP client (Filezilla etc) then after you log on just drag and drop the files that you want. If you want to do this from a browser window, then here's the string that you will need (you may need to copy and past the whole string):

FTP://owners_990.immersifi.com:combfilter1@immersifi.com

For those using an FTP client, the log-on details are as follows:

Username: owners_990.immersifi.com
Password: combfilter1
Host: immersifi.com

Thanks for reading this, and I'm curious to hear comments from otehr 990 owners; I hope that it's just my unit...or (best case scenario) that this can be fixed in a firmware update.