Hello everyone. I have an onkyo tx-ds797( no hdmi), outlaw 7500,sony bdp-s550, velodyne sms1 and for speakers polks rt2000(l/r) dcm(ctr) polks rt600I(s/r-s/l) and lfm-1ex(sub). My avr has 5.1 multi-channel inputs so decided to take advantage of the new formats that blue rays have.

I have the coax and multi-channels 5.1 from the s550 to the avr connected. When playing blue ray movies like iron man, transformers, x-men etc, its seems when using the muti-channel set up to get the lossless sounds dolby true hd and dts hd that they are not as loud, clean or dynamic as using the coax set up with d/d and dts with the same blue ray movie. So i thought that i was doing some thing wrong because most remaks are positive when dealing with multi-channel 5.1 set up for the dt/hd and dts/hd. I took the sound level meter and compared the avr levels with the s550 levels(multi-channel set up) and they are very close. When watching a blue ray movie the difference is 10db between multi-channel and dd/dts which thats ok but when I turn the avr 10db for multi-channel set up its does not sound as good,clean and dynamic as using coax set up with dd/dts formats.

So I'm wondering if other people are getting same results or is it that my avr does a good job with dd/dts. My concern is that after reading an article on HE where they talk about how small the difference between dt hd,dts hd and uncompressed pcm was, that got me wondering. When i get the 997 and play the new formats will it sound like the results I'm getting with my multi-channel set up since they are lossless audio?. Just wondering and I know no one has the 997 yet but may be those of you that have the new avrs that handle the new formats can share your thoughts. This is the article on HE. http://www.hedmag.com/node/Dolby_TrueHD_DTS-MA_versus_Uncompressed_PCM?page=0%2C1

Thanks ramon.

The TX-DS797's multichannel analog input is going to be a pass-through with no bass management, no speaker delays, and very possibly no channel trim. Have you calibrated the S550 so that it is providing these? Another thing that I wonder about: how does the system sound when you compare the coaxial output to the analog output with a Dolby Digital or DTS track? In other words, what happens when you watch a standard DVD on the S550 and switch between the coaxial and analog connections? After all, if the Onkyo's DAC's and analog section are noticeably better than the S550's, that may contribute to the situation you are describing.

As for the 997, I would expect several differences. First, my experience with the 990 makes me suspect that the 997 is going to sound better than the Onkyo 797 does. That will be true for all inputs. Second, the Sony S550's analog section will no longer be a factor, as it will send the audio as either an undecoded bitstream or decoded LPCM digital audio.

I haven't been able to do a comparison such as what is discussed in the article you linked to, but the basic theory is sound: the whole point of lossless compression such as TrueHD and DTS-HD Master Audio was to provide access to the original uncompressed studio masters while still avoiding the need to stick six or eight channels of uncompressed audio onto a disc. If TrueHD and DTS-HD MA are doing their jobs properly, they are just as non-destructive as PKZIP is to computer files - unpack them back into the original PCM, and you have lost nothing.

Hi ramon ;
I have nothing to add to gonk's reply. I was just pleased to find that someone else is still running Polk RT2000s. I've always found them to be fine speakers once you properly adjust for their crossovers.
None of us know what the 997 will sound like, but based on the performance of the 990, you'll likely be blown away with the improvement.

hello Gonk;
Yes i have calibrated the s550 the best I could with info that other users of the s550 have advised. I did use a regular dvd(Transformers) and checked the difference between dd/dts vs analog multi-chanel and db are still lower and while doing that I realized that my center channel does not work with multi-channel set up. The l/r are doing most of the work and that could explain the big diff. I did do a sound level ck with s550 on multi-channel set up and all the speakers work fine so its not a connection problem. I'll play with it some more tonight.
I did notice a big diff between blue rays and regular dvd on picture and sound, amazing. I'm really glad to hear that the 997 will sound much better because I had the 990 in my hands when they mention the 997 so as hard as it was i decided to wait for the 997 and send the 990 back.

Hello Koyaan: They are great speakers and with the addition of the lfm-1ex sub and the sms1 my system is great and I can not wait until the 997 gets here.
thanks Ramon

If the center is out of the mix, that would certainly detract from the overall quality. Hopefully you'll be able to find what is causing that.

Hello again;
What i had was the s550 to coax and avr to multi-channel which gave me only two channels. Now that I have every thing correct the db are still low in multi-channel compared to dd/dts. Like you said Gonk the multi-channel is pass-through and thats probably why. The 10 days that I had the 990, i was able to hear a much cleaner and more detail sound then the onkyo 797 so i can only imagin how much better the new formats will sound going thru the 997.
Thanks for the info Ramon