U sure you don't have your outputs reversed??? Or the wires at the amp? I hate to even ask that but... The simplest solution is often the best one.

I have another suggestion for trying to adjust the delay by ear. Going for a perfectly centered image is pretty difficult when you aren't equidistant from the speakers - especially in the tight confines of a car. Arrival time is only one of the factors. You also have amplitude differences and all kinds indirect sound reflecting off your windows.

Instead of going for a centered image try to find the delay where the image smears the least. Find a track with a strong and fairly isolated center image. Human voice is the best because our ears are evolved to hear differences in human voice very well. (I used Joni Mitchell.) Now close your eyes and focus on the voice while moving the delay around. Get a feel for how it changes. Try to find a point where the image seems the most narrow and focused. It's hard to explain but as you move the delay left and right you should be able to hear the image drag and smear in each direction as difference in arrival times becomes greater. With the correct delay the image won't necessarily be centered left/right but it should sound the tightest and most focused. And remember that the perceptual shift will be in the opposite direction as the delay. (i.e. as you turn the knob left and delay the left speaker the sound will shift towards the right because it will be arriving sooner from the right)

I adjusted it by ear first and was very pleased with myself when I got the tape measure and discovered I was spot on.

-Dylan

Shonky, thank you so much! This is an awesome hack. The difference in sound quality is tremendous. I've always been unsatisfied with the imaging of my system and this helped a lot.

The hope for user enhancements like this and, of course, Mark Lord's great Hijack kernel is one of the primary reasons I bought the Empeg. I'm so happy to see skilled people taking advantage of the flexibility of the platform.

-Dylan

Okay, time is running out on this one.

I'd still like to see this stay in Hijack, but the code does need to be tightened up some. Have a look at it, please.

-ml

I'm absolutely certain. My balance controls work correctly. When I play audio test CD's, left and right channels come out correct. When the balance is adjusted al the way to the left, there is no sound coming from the right side. Visa versa. When I adjust the delay, it is backwards. I am sitting physically on the left, and adjustments 4ms left will place the center point of the sound stage on the far right side of the car onto the corner of the dash. 4.1ms to the right will place the soundstage centered perfectly in front of me (on the left side of the car). I went through the rounds *again* yesterday and I can confirm that this is the case. If I adjust any further to the left, the sound smears all over the place and sounds like complete garbage.

Is there anyone in the south bay that wants to bear witness to this?

Calvin

Remember that the given acoustics of a car will vary. I would guess that in some cars, the delay would need to be adjusted one way, and in other cars it would need to be adjusted the other way.

Depends entirely on speakers, speaker locations, and acoustic reflections I think.

That's my gut feeling as to what is happening. I PM'd Shonky as to such. I would like a witness so I can feel like I am not crazy. ;-)

Calvin

Have you looked into volume adjustment yet? I just played with your adjustment on the way home tonight and I'm quite impressed. Of course now I also have to make slight adjustments to my front/rear gain (starting to hear too much from the rear).

Any progress on preset selection? This really needs a quick way to toggle through two or three presets (pluss OFF) without going into the hijack menu.

Bruno

This is the way it is supposed to work. And... the left right setting DOES make sense, even though someone mentioned in a previous post in this thread cited the contrary. Tony is correct - YMMV - "as long as it sounds good" I say.

regards

I'm working on the CPU usage issue and the glitch at the moment. Presets are a little way off yet, I think.

Sorry, I just have a lot of normal work on at the moment.

Mark,
I'll try and have something to you in the next couple of days. Is that OK?

>I'll try and have something to you in the next couple of days

Sounds good to me.

Cheers

I messed with the L/R delay a little more today and noticed that in my car, I need to move it in the opposite direction as I do when listening on headphones. And my car is not wired backwards (balance is still correct), it's just that my soundstage isn't particularly distinct in my setup (I only have door speakers) and the rear speakers are louder than they should be for proper soundstaging. It's all about reflections etc...

Oh Hell yeah! How did I miss this thread before now.... I am very thankful you implemented this!

This was the only thing I missed when I switched to the EMPEG. This is one of the features I wanted so bad that I bought a used external pocessor to do the same thing..... guess I can uninstall that now.

This has made my day!

Anyone want to buy an Alpine 6 channel phase processor? Guess not on this forum .

Wel, in the end, that's not really a problem, I think. Just rotate the knob untill you hear the center of the stereo image right in front of you, and that's it. As Tony said, maybe surfaces, material, shape and speaker location in your car interiors are such that you need to delay the speaker further from you. Weird, but I thnk in theory it is possible. One more reason to use this feature, I'd say...

you might check to make certain that your speakers are wired in phase as well...
--
sancho

A reduction in volume as appropriate for the set distance should also help. A time delay only is not sufficient to properly tune the soundstage. it certainly works better for some songs than others.

It's mostly suited to center non-continuous tones that exist at the same level on both L & R channels. It doesn't work well for in-sync tones of a different pitch, nor for continuous tones. For example, using a long test tone, this patch shouldn't affect the perceived soundstage.

The end result of applying delay only, is that you have sound sources that are equidistant, except the one with the delay has a perceptually louder volume. It's similar to having a pair of loudspeakers each 10 feet away from you with the balance shifted to the left.A reduction in volume as appropriate for the set distance should also help. A time delay only is not sufficient to properly tune the soundstage. it certainly works better for some songs than others.

It's mostly suited to center non-continuous tones that exist at the same level on both L & R channels. It doesn't work well for in-sync tones of a different pitch, nor for continuous tones. For example, using a long test tone, this patch shouldn't affect the perceived soundstage.

Bruno

Is it possible to compensate this volume using the balance left / right.

When i set up the delay patch I noticed that the closer speaker (left) was louder that the right.

I changed the balance to right until I had a 'perfect' sound picture.

Now that rocks with my AC/DC's Hard as a Rock song ...

They're in phase. I go through a tuning CD every 6 months or so.

Calvin

You are totally correct Tony!

When I am using headphones, if I set 4.1ms of delay to the right, the soundstage moves to the right. If I set 4.1ms of delay to the left, the soundstage moves distinctly to the left.

In the car, moving 4.1ms of delay to the right causes the soundstage to move to the left. (!!!!!!) I'm not crazy!!!

Calvin

Your headphone scenario is broken. What you just described for IN-CAR is the correct behaviour. Did you just describe them backwards? Because this is the opposite of what I thought you described before.

Bruno

Sure, you can use balance to do the volume adjustment. But using balance is doing it by ear. The amount of reduction in volume per click doesn't translate to a specific distance. Plus the fact you now have to set up two controls. I really want this all taken care of in one shot so it's easy to turn it ON/OFF and well as cycle through at least two presets (one for driver the other for passenger).

Bruno

Consider this, if you haven't done it. You sit on the left side of the car. Your left speaker is something like 2' closer to you than the right speaker. Punch up into the empeg a left delay of approximately 50cm. Now put in a nice vocal CD and see if it doesn't give you a centered image.

In my experience with my old head deck, with a built in DSP, varying the image just "a little" left or right was very confusing. But when you really cranked on it, out of nowhere, there it was - the singer right in front of you.

I have a 3rd gen Eclipse, sonically not all that different from yours or any other small car really, and at about 41.some cm it's a dead on image right in front of me.

Sure the standard balance control is fine enough to this purpose? Did you try? I agree that changing volume is exactly what balance does, but as I think you were saying before (correct me if I am wrong) the balance control is too imprecise to do that properly... ? Anyway, for some reason I never noticed a difference in volume, even though it should be there in theory. I'll try to play with the balance too...

I would like to know if the Delay Patch is apllied for Front Speakers only or if it could be implemented for the Rear ?

At this time I don't have rear speakers but in the near future I will have.

Maybe is it not necessary ?

It is applied to the channels. So both front-left and rear-left speakerts will be delayed if you delay the left channel. I think it was discussed before that fron-rear delaying is not currently possible from the empeg sw, since it only outputs left and right (2 channels) and not front-left, rear-left, front-right, rear-right (4 channels). It's a hardware "problem", not a software one.


I have to say, though, that with just the current function my car installation sounds amazingly well... I honestly do not know whether I would need and benefit from anything like front/rear delay. I'm just assuming, now, I admint I should at least try. The fact is that I could HEAR the problem with my stereo image before the current patch was made. Now it does seem perfect, I do not hear any problem.
Ehm... Ok, I just realized I do NOT have rear speakers, just a sub. Ok, I'll go to lunch. You guys stop laughing...

But the distance LeftHear/Left Front Speaker is not the same that distance LeftHear/ Left Rear Speaker.

So if the patch is applied to chanel left or right, delay for left rear channel is almost all installs upper value that for front so why even apply it.

Ah, you are telling me that we cannot do else that delay only left or right channel ...


I remove my question !!!!!

OK, taym is perfectly correct. It is a hardware thing that prevents us delaying all four channels individually. If you think the patch is pointless then you don't have to use it.

Also rear speakers shouldn't be used for stereo imaging in my opinion. They should be used for "rear fill" only. I believe in the theory that the rear speakers should be faded out so that they're just not noticeable.

I agree that if you can distinctly hear the rear speakers, they are too loud.

Having the fronts and rears together on the same amount of delay is very nice, obviously better than if it did the fronts only. However (and I know we are hardware limited), delaying the rears seperately compared to the fronts is also nice. Where the left / right delay sits you in front of the stage, as opposed to the left or right side of it, changing the front / rear delay brings you towards and away from the stage. It can make it feel like it is shrinking way out in front of you, or that you are almost right on the stage itself.

This could be done with a variety of aftermarket components, for relatively cheap you could wire in a guitar pedal, if you didn't mind the labor involved actually installing it and converting it for 12V use.

The balance control is very imprecise. My alpine had very fine graduations from click to click, the empeg is very brutish in this regard.

Calvin

I'm pretty certain I'm describing my situation pretty consistently.

I am sitting on the left side of the car. Left hand drive.

If I adjust the *balance* controls far left, the right speakers emit no sound.

If I adjust the *balance* controls far right, the left speakers emit no sound.

If I adjust the time delay to the right, the sound stage moves to the left.

If i adjust the time delay to the left, the sound stage sounds like garbage.

I am pretty sure I did not describe the situation any other way.

I discovered this morning that my patch cables (home) was wired up backwards (!!). I swapped the patch cables to the correct configuration and now even the headphone test duplicates the above described behavior. If I adjust the delay to the right, the soundstage center moves to the left.

Calvin