How sensitive do we think our ears are to time??

[ellisdj]

I have an Arcam P49 power amp on test at the minute.

I ran Dirac to integrate it pefectly with my subs.

After it felt like the central image wasnt quite right it felt a bit off to the right.

I was looking in the dirac options and noticed the left speaker was set 0.1ms in delay compared to the right.

So I was able to detect something wasnt right at the time delay of 0.1ms

ms is milliseconds btw.

How crazy is that.

 

[CnoEvil]

I'm more interested in what you think of the P49. Is it driving the Refs? If so, what do you think? I personally liked the combo, though with an Arcam Pre.

 

[ellisdj]

I will post up some details soon Cno mate yes on the ref 3's

It am still squeezing more performance from the system. I will record some demos this weekend and post them up so you can get an idea.

 

[nopiano]

I guess it's arguable if it is 'time' so much as balance, but that's probably semantic. You've obviously got good hearing! I think my soundbar has a facility to modify the timing to sync with the picture. That's the trouble once you get away from pure analogue (where you only have hum, hiss, noise and clicks to worry about!)

I'm relieved your thread wasn't about ears ageing, as I'm sure my highs are well down on what they were a decade or so back...

 

[ellisdj]

It shows it doesnt take much to ruin the illusion.

I was going to run the whole thing again. I wasnt looking for it just spotted it and realised saved me a load of grief / work.

 

[abacus]

The delay relates to the distance of the speakers to the listening position, and if you get a tape measure out you may find that one speaker is a slightly different distance from the seating position than the other.

While Dirac Live is one of the best out there, nothing is perfect, but it may be worth checking to see if you have the correct calibration settings for the microphone you are using.

Best way is to play a mono signal through both speakers and adjust the balance (Not the timing, as unless you know where the actual image was in the original recording, it is impossible to get it right by ear) to give a central image.

NOTE: Your ears are many orders of magnitude below the microphone/software accuracy, so it’s also possible that your one ear is slightly inferior to the other, (You will need to have your ears professionally tested to find out this) which would also cause this problem.

Finally there is also the psychological element to take into consideration, which is always difficult to get around. (I have a problem with speaker cable lengths, as if I know they are of different lengths, the image always moves to the shorter length, even though using a blind test it doesn’t, hence the reason blind testing is so important)

The above is why it is of paramount importance that you try before you buy, and make the final adjustments how you want, even though it may not be technically accurate. (And others probably also find your settings not correct for them)

Bill

 

[Vladimir]

7ms on average.

 

[ellisdj]

Bill

That's an interesting post but wide of the mark.

I have only run dirac measurements twice.

First time was the first time.

Second time was with the new amp as its volume gain structure is so different the sub integration was off.

Its actually nailed the corrections both times but this time it put a minimscule delay on the left speaker.

It took me a couple of hours of listening to decide that something is not 100% and decided to run the process again.

When you have a very solid central image to your sound its very obvious when its not central. Bearing in mind my room reverb and acoustic conditions.

So after altering the delay to the left I dont feel the need to run the dirac measurement process again as it sounds nailed.

I have got an xlo test CD where the first track is for setting up speaker phase. That is how I could tell it wasnt correct.

The speakers are also measured to the mlp and delay set in pre amp processor.

The delay was 0.1ms and -0.1db that was enough to throw the sound off to me compared to what I am used to.

 

[ellisdj]

It doesn't matter if my ears are not perfect and dirac set things perfectly

My ears were equally not perfect before i ran it to after.

Its also very likely the mic was not perfectly central

And also its measuring in mono I am listening in stereo

So its often stated how sensitive we are to time changes well this is a good example of just how

 

[lindsayt]

The speed of sound is 343 meters per second. In 0.1 ms it would travel 3.43 cms.

At 5000 hz, sound has a wavelength of 6.8 cms.

Treble phase issues? I don't know how audible they'd be?

 

[Pedro]

The speed of sound is 343 meters per second. In 0.1 ms it would travel 3.43 cms.

At 5000 hz, sound has a wavelength of 6.8 cms.

Treble phase issues? I don't know how audible they'd be?

+1

 

[Vladimir]

Apparently we are extremely sensitive to time arrivals of sound, probably function of evolution. We are very insensitive to loudness and we have very short sonic memory. I remember John Atkinson mentioning the threshold of 7ms for time sensitivity, so 1ms seems in the possible range, especially for sound perfection OCD freak like Mr. T. *biggrin*

 

[insider9]

Your experiences mirror my own. I also had Dirac skewing image and also could hear it. The first time it wasn't straight away clear as to what happened but I knew something was wrong. And by the way my listening spot is fixed and central.

If you know your system I'm not at all surprised you'd notice that a vocal was to the right/left by even just a bit. In some tracks you just expect it high and central and if it's not there something must be wrong

 

[ellisdj]

It wasnt glaring obvious what the problem was or even there was a problem.

I just wasn't 100% sure, something didnt seem right

It was a surprise to me to be that, but I thought it was interesting to share

 

[insider9]

Absolutely! It may have something to do with the sub. I'm guessing yours isn't place centrally also.

To add another curious observation to this thread I've noticed how big of a difference opening a window makes when using DSP. I was shocked to discover this. In all fairness it makes sense but it's not something I'd immediately consider. Look at the graphs below it's something I was messig about when designing filters.

Closed windows - here

Open windows - here

Overlay - here

 

[nopiano]

Absolutely! It may have something to do with the sub. I'm guessing yours isn't place centrally also.

To add another curious observation to this thread I've noticed how big of a difference opening a window makes when using DSP. I was shocked to discover this. In all fairness it makes sense but it's not something I'd immediately consider. Look at the graphs below it's something I was messig about when designing filters.

Closed windows - here

Open windows - here

Overlay - here

Brilliant to see the graphs like that. The trouble is that everything like that makes a difference :- doors, windows, rugs, curtains, bookcases, record storage, chairs and sofas, you name it.

All that said, for me those are usually the differences my ears can accommodate and adapt to, unless there is something strange going on, whereas things like channel balance - where we came in - are impossible to ignore!

 

[ellisdj]

I seal my room best as possible with fire type seals around the doors.
You dont want pressure escaping especially not asymmetrically.

I dont have any windows in my room but do have 2 sets of doors. One is a bi fold that is a sod to seal as you can probably guess.

Mad to see graphical proof like that though - good skills insider dude.

 

[insider9]

I've done it without DSP as well and noticed that DSP only exacerbates these issues. Changing conditions make a hell of a difference to DSP filters. Also seen the extent varied depending how wide the windows were opened You can tell I had too much time on my hands in the last week.

It works exactly the same as with ports on speakers but not something most people would think of especially in the summer months when it gets hot.

 

[CnoEvil]

I will post up some details soon Cno mate yes on the ref 3's

It am still squeezing more performance from the system. I will record some demos this weekend and post them up so you can get an idea.

Just a litttle reminder. *mail1* *scratch_one-s_head*

 

[ellisdj]

I will post up some details soon Cno mate yes on the ref 3's

It am still squeezing more performance from the system. I will record some demos this weekend and post them up so you can get an idea.

Just a litttle reminder. *mail1*  *scratch_one-s_head* 

Recording the demos now.

 

[CnoEvil]

I will post up some details soon Cno mate yes on the ref 3's

It am still squeezing more performance from the system. I will record some demos this weekend and post them up so you can get an idea.

Just a litttle reminder. *mail1* *scratch_one-s_head*

Recording the demos now.

I just want you to dscribe what you are hearing and how the P49 compares to the Bryston through the Refs.

Playing a dem on Laptop speakers tells me little.

 

[ellisdj]

Plug some half decent headphones into a smart phone / your laptop and you will get an idea this time.

I am checking the recordings now and they are crackers.

I will do a full review of it CNo mate, but I needed some time to listen through some changes to form an opinion.

Its bloody good if you want a quick answer

 

[CnoEvil]

Its bloody good if you want a quick answer

It's good to have my opinion backed up. People have found that the Refs can sound analytical, but (imo) that's not the case with the Arcam A49 or C49/P49 (especially with a Linn DS).

https://www.whathifi.com/forum/hi-fi/if-i-was-starting-again

 

[ellisdj]

I can see why they might think that. I have had them punish me quite a few times for things I am doing wrong.
Analytical is probably because they dont have things right and they are hearing it.

I can see why Kef picked these arcams to demo the speakers - this one sounds balanced and nothing stands out incorrectly.
That has been the case from the first minute, I have managed to squeeze a more full bodied and direct sound now than I did on day 1. This amp will never cross that line though into for some maybe magic others not so. I dont want to say anymore, I have some good stuff planned for my channel review

 

[CnoEvil]

I can see why they might think that. I have had them punish me quite a few times for things I am doing wrong. Analytical is probably because they dont have things right and they are hearing it.

I can see why Kef picked these arcams to demo the speakers - this one sounds balanced and nothing stands out incorrectly. That has been the case from the first minute, I have managed to squeeze a more full bodied and direct sound now than I did on day 1. This amp will never cross that line though into for some maybe magic others not so. I dont want to say anymore, I have some good stuff planned for my channel review

The Arcam Class G in their top 2 channel amps, is the closest I've heard (at half sensible money) to my AMS 35i...and that's paying them quite a complement.