Speaker delays on Yamaha

[RIDGMONT]

Can anybody help set up the speaker delays on a Yamaha RX-V420RDS. The manual is very limited, it suggest that the sound from each speaker should be about the same but does not details the adjustable delays on the speakers, particularly the rears.

Due to contraints within the room (and my wife!) I am unable to place the speakers equidistant from the listening point. The rear speakers are about 1.5 metres from the main listening point whereas the front speakers and the centre areabout 3.5 metres away. The Yamaha does not have the facility to set up by distance, unlike some Pioneers that I am aware of, but is set up by milli-seconds. The manual does not explain what value are realistic.

There is a minimum setting of 15ms which seems too high as it is noticable that the sound is later from the rears and hence a slight echo is created.

I think the value needs to be less than 15ms due to the distances involed and for this to work properly.

At another part of the manual it is suggested that 1ms is equivalent to 30cm distance.

I would be grateful for any comment on this.

[Bapapapa]

1ms = 30cm/1 foot

You need to measure the distance from your listening position to the mains/fronts and then the distance to the centre speaker.

Say the front mains are 9 feet away and the centre is 8 feet away, then you need a 1ms delay on the centre so as to make it seem further away/equal to the mains.

Reduce your rear delay to around 4/5 ms.

Don't forget to run the test tone and balance each speakers volume correctly.

Disclaimer: Don't really understand the implications of the rear delay myself, so I could be talking complete b0ll0cks

[Spikey]

Download this file, it'll tell you all about it and how to work it out.

http://www.dolby.com/tech/co.br.0103.DDFAQ.pdf

[Phill]

It's all about timing, the delay is there to compensate for the finite ammount of time it takes for sound to propagate. As Baps says it's 1ms/foot.

but...

Pro-logic has an exrta 15 ms delay which is there because of sound leakage from the fronts to the rears. The extra delay de-couples the surround effects from the front speakers so that speech and on-screen effects sound like they're comming from the front and not all arround you.

So, if you play a DD DVD, check the delay setting, compare those to the delay settings in pro-logic, you should find that the decoder sticks an extra 15 ms on in pro-logic mode.

[Spikey]

As a note of caution when changing delays, a lot of those iffy surround modes you find on av amps deliberately have odd sounding delays to create their effects.

[RIDGMONT]

Thanks Spikey the Dolby document is excellent and perhaps should be included on the Terms and Conditions of this site!

The 15ms set delay for Dolby Prologic raised suspision and when the Amp is is Dolby Digital Mode or DTS the delay can be lowered from 15ms to 0, this has therefore allowed me to set delays I wanted. 10ms reduction in delay is quite substantial and definitely noticeable.

Thanks to everyones help on this one.

:clap: