Help! - Is there something wrong with my 6 month old receiver?

[Hems]

I noticed something strange with the sound coming out of my surround speakers when my receiver is in dolby pro logic/dts neo mode.

Apart from the usual surround effects you get I’m also getting a lot of distorted sound in the background. I’m assuming this is not normal. I switched to a TV channel with 5.1 output and that seems to be ok so was wondering could there be something wrong with my receiver?

I have KEF3005SE speakers and a Denon receiver which is only 6 months old and has been configured using auto setup and then an SPL to maintain correct levels. My receiver is also connected to a SKY HD box via a QED performance coax cable.

Does anyone have any thoughts or suggestions as they would be really appreciated?

Thanks

 

[Anonymous]

Is it a loud distorted noise, or can you only hear it up close ?

IMO when your only watching a standard audio transmission, the NEO & prologic setting creates an enhanced but falsed rear sound. On my system, close up to the speakers I can hear a distorted noise but nothing that's audible during normal use !!

Maybe your rear speakers are set too loud?

 

[Hems]

I can only hear it up close ?

Speaker are definitely set to the right levels because I used an SPL to configure them.

 

[The_Lhc]

Hems:I can only hear it up close ?

Are you asking or telling? If you can only hear it when you're right next to the speaker, then, well, move further away!

This is normal, it's an effect of the DPL processing trying to pull out surround channel information that doesn't actually exist in the original soundtrack. Sit in your normal position, if you can't hear it then, forget about it. If you can hear it in your normal position then your rear channels are too loud.

 

[Andrew Everard]

Probably phase problems on the sound being transmitted, or maybe even the soundtrack being sent at too low a level. It can drive DPL/Neo:6/Neural THX processing crackers.

Nothing wrong with the receiver - just switch back to stereo when you hear the problems.

 

[Hems]

Thanks for clarifying this.

 

[Anonymous]

I have also experienced similar problems with broadcast sources on both my previous Yamaha DSP-E492 and current Onkyo TX-SR806 when set to Pro-Logic or Neo. With speaker setting balanced (auto set-up on Onkyo) there is high frequency distortion from predominantly front L & R, less on rear speakers, but not centre. This can be very noticeable, but varies depending on which TV channel or programme is being viewed. Most noticeable from original Sky digital box hooked up by analogue phono, but also from Sony RDR-HXD860 hard disc recorder and BT Vision both connected by HDMI. DVD connected via co-ax OK on 2-channel and multi-channel DD or DTS. DVD set of "24" sounds OK on Pro-Logic.

I approached both SevenOaks who supplied the Onkyo and Superfi, but both said they had never heard of the problem.

Speakers: Front B&W 601, Centre B&W CC6, rear Kef 55S. Front L & R driven via Onkyo pre-out to Arcam Alpha 8R.