delay settings on receiver for surround and rear channels

[hungmeister]

Hi everyone,

Sorry if this has been asked before. I can't seem to get the search function to work properly on the Klipsch forum (I always get 0 returns for any search I attempt), and so here's the question.

What's the rule/formula for the time delay setting when calibrating? I have an SPL meter, and I have all speakers "equalized" to 80dB, however there are delay settings on the Onkyo 801 receiver I have. I have no idea what criteria to use for this. Is it the distance of each speaker to the "sweet spot", or is it the distance of each speaker cable? And finally, is it 1ms for each meter, or 1ms for each foot? HELP!

-Hungmeister

[damonrpayne]

Hi and welcome to the forum:

I'm not familiar with your specific receiver, but most newer ones I've seen ask you to type in the distance and it will calculate how long the delays should be. The distances should be distance from the speakers to your ears in the sweet spot. The idea is that all the sound should reach your ears at the same time if its meant to.

As for how many milliseconds, look up the speed of sound in meter/second or feet/second and do the math ! Good luck

[WMcD]

The speed of sound is 13500 inches per second in air.

Therefore it is 13.5 inches per millisecond. That can be rounded down to a foot per millisecond for estimations.

Of course that also allows people to say the speed is 1000 feet per second.

You may already know this from summer camp. If you see the lightning and count one allegator, two allegator, etc. (this is to say, seconds) . . . if the thunder arrives in 5 allegators, the strike was a bit over 5000 feet away or one mile.

Therefore, what you learned in summer camp will help you set up your HT system. Smile.

Gil

[hungmeister]

I thought about it more, and this receiver already has a way to calibrate the dB from each speaker to the listening position. I've already done the calibration with an SPL meter (from Radio Shack). So it doesn't make any sense, why then I would need to calibrate the distance of each speaker???

So the manual says that the calibration will give a wider (width wise of the room) and longer (length wise of the room) sound? A bit too much technology if you ask me, so I'm leaving these dealy settings at 0ms.

If you all think otherwise, let me know.

Thanks!

[WMcD]

It is not a matter of level, that is to volume. It is delay.

This originally came up in the days of matrix Dolby. There was quite a bit leakage between the front channel recording and the surround recording. Therefore it became important to find something so that the ear-brain can distinguish surround sound as actually coming from the surrounds.

That something was delay. If the ear-brain hears the sound out of the surround well after that from the front channels, it calculates that is a different source. Time delay necessary to fool the ear-brain was about 10 mS, or 10 feet worth of delay.

However please consider the difficulty caused by the typical, or maybe atypical, placement of surrounds.

Sometimes the mains are 10 feet in front of the couch while the surrounds are 5 feet on either side. I.e. the surrounds are 5 feet closer.

So you have to come up with an additional 5 mS of delay to get back to the goal of 10 mS effective.

I say the placement is atypical because everyone's speaker placement, and therefore and difference in distance, varies.

A similar problem arises with the front center. It would be nice if the three front speakers were equidistant from the listener, on an arc. However, often the center front is closer than the flanking units. So this can be corrected with a bit of delay too.

Natually everything has to be done with delay. This fairly easy to accomplish these days. However, no one has found a way to speed up the signal by any amount in real time processing.

Best,

Gil

[Dale W]

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On 5/25/2004 7:42:07 PM hungmeister wrote:

A bit too much technology if you ask me, so I'm leaving these dealy settings at 0ms.

If you all think otherwise, let me know.

Thanks!

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WRONG !!!!!!!!!!!!

Get out a measuring tape and enter the proper distances , if your processor is worth it's salt !!! the difference will be well worth the time spent .

If your into screwing around with settings ? these 2 fuctions are the most fun to play with and will yield the most audible changes . Nothing is written in stone , changing the db output and distance settings can help you shape your room .

[wrench_peddler]

The delay is a very important setting. My belle center is about five feet or about 5 milliseconds closer to my ears. By adding 5 ms delay, I have electronically moved my center speaker back 5 feet which is 2 feet deep into my wall. You will notice a difference. Gunshots now come from the entire front of the room instead of the center with an echo in the left and right corners. The same can be done with the rears. If they are closer to where you sit, you can scoot them back with the delay so it sounds like you are in a larger room. If the movie has a gunshot in the front and you don't have a delay on the rear speakers, you may hear the richochet before the gun goes off. That would suck.

[hungmeister]

Oooooohh.. spicy! Nice description of what the delay settings will do for the movie experience. I've totally missed it then.

So, can someone explain to me with concrete numbers how I should set up the delay then?

Here is my current setup:

L C R Sub

LS Me RS

LR RR

The distance between "me" and the respective speakers are roughly:

L: 12ft

C: 12ft

R: 12ft

Sub: 12.5ft

RS: 8.5ft

RR: 9.5ft

LR: 8.0ft

LS: 7.5ft

I have all the speakers at 80dB with an SPL meter (SUB's a bit higher at around 82dB). If it matters, I'm running RF35/RC35/RF35 RW-10sub with Bose satellite cubes for the side and rear surrounds (will replace with Gallo Adivas sometime this year).

The Onkyo TX-NR801 has these delay settings:

1) Relative Center Delay

2) Side surround (not a separate right surround, left surround setting).

3) Rear surround (not a separate right rear, left rear setting).

What should my three delay settings be?

THANK YOU SO MUCH!!!!!! (can't wait to try it out)

[hungmeister]

Sorry, forgot to mention that the Onkyo receiver also has a menu item where I enter all the speaker distances from "me/sweet-spot".

I'm clarifying this since one of the responses stated I should get out my measuring tape...

So all I am asking about is the delay.

Thanks again!

[Dale W]

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On 5/26/2004 1:57:14 PM hungmeister wrote:

Sorry, forgot to mention that the Onkyo receiver also has a menu item where I enter all the speaker distances from "me/sweet-spot".

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So in that menu , what incriments are given ?

Is it asking you for distance in feet ? inchs ? meters ?

Just measure from your seated position to each speaker then enter that distance in whatever measurement the reciever is asking for .

If you want the sound from your surrounds to arrive faster ( were talking milli seconds here ) then trick the processor by telling it the speaker is further away than it really is.

Do you have a full range selection for the speakers ? does your menu ask if your speakers are large or small ? This function can misdirect alot of information over to the LFE if you configure for small . I changed this function on my sisters HT rig and it changed from night to day . The unit she had purchased was pre-set at small and she never changed it .

[wrench_peddler]

It looks like the Onkyo will do the calculations for you. I would guess you could do it either way. If it were me, I would add 4 ms delay to the surrounds, both sides and rears. I would be that if you enter the distances into the Onkyo, it would add about the same amount. Good luck.

[hungmeister]

I have the setting for fronts and center at large speaker settings. I played with the small speaker settings for the fronts and center, but for some reason it didn't feel right, so I put it back to large settings.

So are we saying that the two settings

1) distance of the speakers to the sweet spot,

2) delay

are redundant? And that I should only set one and leave the other at 0?

Maybe my understanding of it in the first place was correct, so that the delay is only to make the room "sound" longer and wider?

Like I said before, too much technology.

[Dale W]

Your confusing yourself needlessly , delay and distance is the same thing .

Your setting the delay to componsate for the seated positions distance from the speaker , by doing this your trying to ensure that the proper surround and main speaker sounds arrive at your seated position at the proper time.

It's " ALL " about timing , but remember were dealing in milli seconds here .

What your pocessor is seeing when you adjust these settings is signal delivery. If you were sitting 5 feet away from the mains but the rears were 18 feet behind you and all your delays and or distances were set a zero feet , then your not getting 100% performance from your rig .

In this above mentioned example , your siganl processor would compansate for the rears being 18 feet away and send there signal first so that it arrives at your seated position roughly at the same " time " as any other channel it's mixing with or overiding .

Hope this helps a bit more , if not we'll start again at the beginning for you .

DALE

[hungmeister]

So if delay and distance are the same thing, why would the Onkyo receiver have settings for both?

I have already set all the distance settings accurate to half a foot. And then I have delay settings that I can set as well.

Should I leave the distance to all 0, and set the delay? Or should I leave the delay to all 0, and set the distance? Or do I set both to non-zero? And if the latter, how do I determine what's right so that the sound will reach the sweet spot from all speakers at the same time.

Thanks for your patience. I'm just trying to get this thing set right. I'd call Onkyo, but they're not too helpful in tech support there.

[hungmeister]

Last night, I put the relative delay on the center to be -3.0ms while leaving all the distance settings as they were. Maybe it was just brain psychology, but it actually felt like the sound was coming from behind the tv (my center speaker sits atop my tv). Kind of spooky, but cool at the same time. So anyway, I think I understand more about distance/delay, even if my understanding isn't perfect.

Thanks all for trying to enlighten me.