6.1 settings

[fnou2]

Hey Guy's

I have a dedicated screening room and so far I have been using a 5.1 system. Recently I bought a new central speaker and since my material (rotel and nakamichi ) allows me to add speakers, I tried putting a 6.1 system.

I had two issues:

1 - I used the Avia disk that includes 6.1 setting tones. Once I set the system using a DD EX test tone, I tried the DTS ES test tone. Something strange happened. The test tone ES discrete was calibrated correctly but the ES matrix had the side surrounds at 2db lower than the rest of the speakers. Maybe the matrix coding takes away part of the information form the side surround and therefore reduce the volume but that would not make a lot of sense.

2 - I have new dipoles surround (KEF 2ds). I read somewhere that I should have the delay to 0 because they are dipoles. Is that true or should I put the same delay then normal speakers? And how can you test if the delay is correct?

In the event that I want to keep the 6.1 setting, my pre amp Rotel (rsp 1066) create a rear channel for 5.1 sources. Intuitively I believe that this channel should be close to a matrix coding. Does that mean that I should set the surrounds speakers to 2db higher?

Maybe the right way is to use 5.1 for 5.1 coding and 6.1 for 6.1 or 7.1 coding.


I hope somebody can help me.

Thank You

[David Meek]

Hi Frederick, welcome to The Guide! :later:

Hmmm, some good questions here. Someone with more knowledge of the codecs should jump in here (I hope) and correct me if I'm wrong.

1) The discrete ES is just that - it's own fully developed and individually processed channel for the center rear. The matrix ES is a derived channel - the left rear and right rear channels are analyzed and a rear center channel signal is created by the processor out of these matrixed values. For example, it has to keep the sound of a helicopter flying overhead going in the same direction. Now as to why the matrixed channel would be down 2dB, I'm not sure. It most likely is a function of your processor. I'm running a Yamaha RX-V1 and I remember my values being off from setting to setting, but I don't specifically remember it being 2db off for this. Also, I'm using di-poles for my three rear channels (Boston Acoustics VRS Pros). Unless you can't set the volume level to compensate automatically (and I think you can with the Rotel), I wouldn't consider this something to be concerned about.

2) Delay should be independent of speaker type. It's a function of distance from the speaker to the listening position. You measure from the face of each of your speakers and put the farthest speaker at a zero value. Then up the values of each of the speakers as they get closer to the listening position. The idea is to have all of the channels' sounds reach your sweet spot at the same moment, thus giving you the most coherent and immersive soundstage. Now just a quick explanation di-poles. With di-poles you have a different sound than with a bi-pole or direct-radiator. The di-poles generate a null that surrounds your listening position thus giving you a more diffuse, and more difficult to directionalize source. The null is created by the opposite-facing drivers firing out-of-phase compared to bi-poles which fire in-phase, and direct-radiators which are a standard point-source without an opposite-firing driver.

3) Selecting a matrix format shouldn't be a problem (with the db-level issue resolved). If you want to listen to a 5.1 in 6.1, select the matrixed option and let your processor do its job. If you don't like the result, you can always turn it back to 5.1- it won't damage the unit.

Good luck.