SDA toe in

allstock

Now that I have your attention... It is well known on this forum that "toeing in" your SDA's is a sin akin to crushing kitten skulls or kicking your dog, but how many have done "any" experimentation with anything other than parallel to .00001" SDA's to note the results? I had to move mine the other day to deal with a carpet issue and had some to kill, the results are interesting to say the least...

Mikey081057

Mine are too too heavy to be effin with although i have thought about using HD cables to strap them to my head and use them as headphones

gudnoyez

Mine sound best 6 Inches from the wall 4 feet apart never tried the toe in on any speakers I own, not mentioning the least what were the results?

Mikey081057

Toe -in seems to be recommended for HT configs and dune buggies

allstock

Yes I made a set of "shoes" to go under the spikes so I could slide them on the carpet by myself. While they were like that I decided to do a little experimentation, I've owned them for 17 years and have NEVER had them set up other than perfectly measured parallel. Very eye (ear?) opening to say the least. Interesting you mentioned headphones, because that's basically what they sound like toed in more than 1". However a slight toe in of one or both I can see fixing some SDA anomaly such as one side being a different distance from the sidewall for example. Not everyone has a "perfect" SDA set up, maybe 3' from one side wall and 10' from the other. 1/8" to 1/4" seems to make a huge difference, for better or worse obviously.

Mystery

Mikey081057 wrote: »

Mine are too too heavy to be effin with although i have thought about using HD cables to strap them to my head and use them as headphones

Not a bad idea...

Mikey081057

Now were talkin' some serious headgear!

Schurkey

I moved to my 1Bs from corner horns. Corner horns, by nature, have considerable toe-in.

That said, I don't know why I'd screw-up the phase relationship between the SDA signal and the stereo signal by toeing the speakers. While the treble and upper midrange would no-doubt increase due to on-axis listening, and there'd likely be less side-wall reflection, the required time-delay for the SDA signal vanishes.

westmassguy

The engineers that designed the SDA/Interaural crosstalk cancellation forgot what most of us know about speaker design. With conventional speakers, toe-in, toe-out, toe-up, toe-down, knock yourself out experimenting, SDAs, not a chance. The equilateral triangle between the speakers and you, with the speakers precisely parallel with each other is critical. Anything else will skew the out of phase dimensional signal, and will not be SDA, it will be something else. There are placement adjustments that can be tried, but toe-in is not one of them. If proximity to an adjacent wall or corner is affecting the perceived loudness of one channel, I would ever so slightly adjust the gain for that channel, either at the power amp, or the balance control. Acoustical treatment, sound absorbing panels could also be tried, others can chime in on that.

george daniel

SDA toe in,,,,,blasphemer,,, burn em at the stake!! Lol

allstock

westmassguy wrote: »

The engineers that designed the SDA/Interaural crosstalk cancellation forgot what most of us know about speaker design. With conventional speakers, toe-in, toe-out, toe-up, toe-down, knock yourself out experimenting, SDAs, not a chance. The equilateral triangle between the speakers and you, with the speakers precisely parallel with each other is critical. Anything else will skew the out of phase dimensional signal, and will not be SDA, it will be something else. There are placement adjustments that can be tried, but toe-in is not one of them. If proximity to an adjacent wall or corner is affecting the perceived loudness of one channel, I would ever so slightly adjust the gain for that channel, either at the power amp, or the balance control. Acoustical treatment, sound absorbing panels could also be tried, others can chime in on that.

The ONLY way to deal with any perceived loudness difference with SDA's is acoustically. If you try to do it electrically you will mess the "SDA" effect because the SDA signal is the difference between L&R. If you change the input balance you change the SDA signal. If you try to use any type of stereo equalization (mono wouldn't matter) it too will mess with the SDA signal. SDA's have "built-in" toe in, the difference in distance from the tweeters voice coil and main drivers voice coil to your ear. So anyhow my experimentation shows that in my particular set up I can easily hear 1/4" of "misalignment" from parallel. Toe in of 1/8" at a time has the effect of extending the soundstage further L&R, to the point that at about 1" (at a listening distance of 12') you have sounds coming from behind you. I'm going to try some toe out tonight and note the changes. I might as well have some fun with it, it takes me about an hour to get them back to perfect alignment again!

westmassguy

allstock wrote: »

westmassguy wrote: »

The engineers that designed the SDA/Interaural crosstalk cancellation forgot what most of us know about speaker design. With conventional speakers, toe-in, toe-out, toe-up, toe-down, knock yourself out experimenting, SDAs, not a chance. The equilateral triangle between the speakers and you, with the speakers precisely parallel with each other is critical. Anything else will skew the out of phase dimensional signal, and will not be SDA, it will be something else. There are placement adjustments that can be tried, but toe-in is not one of them. If proximity to an adjacent wall or corner is affecting the perceived loudness of one channel, I would ever so slightly adjust the gain for that channel, either at the power amp, or the balance control. Acoustical treatment, sound absorbing panels could also be tried, others can chime in on that.

The ONLY way to deal with any perceived loudness difference with SDA's is acoustically. If you try to do it electrically you will mess the "SDA" effect because the SDA signal is the difference between L&R. If you change the input balance you change the SDA signal. If you try to use any type of stereo equalization (mono wouldn't matter) it too will mess with the SDA signal. SDA's have "built-in" toe in, the difference in distance from the tweeters voice coil and main drivers voice coil to your ear. So anyhow my experimentation shows that in my particular set up I can easily hear 1/4" of "misalignment" from parallel. Toe in of 1/8" at a time has the effect of extending the soundstage further L&R, to the point that at about 1" (at a listening distance of 12') you have sounds coming from behind you. I'm going to try some toe out tonight and note the changes. I might as well have some fun with it, it takes me about an hour to get them back to perfect alignment again!

I beg to differ, since I've made a slight adjustment to the right channel gain on my 2As. The right speaker is 5' from a corner, however I have a large antique desk that is within 2' of the right speaker tucked into that corner. Reflections off the desk made the right channel appear louder. The slight gain adjustment compensated for this, with no degradation of the crosstalk cancellation.
If you feel toe-in will correct your problems, knock yourself out.

allstock

westmassguy wrote: »

allstock wrote: »

westmassguy wrote: »

The engineers that designed the SDA/Interaural crosstalk cancellation forgot what most of us know about speaker design. With conventional speakers, toe-in, toe-out, toe-up, toe-down, knock yourself out experimenting, SDAs, not a chance. The equilateral triangle between the speakers and you, with the speakers precisely parallel with each other is critical. Anything else will skew the out of phase dimensional signal, and will not be SDA, it will be something else. There are placement adjustments that can be tried, but toe-in is not one of them. If proximity to an adjacent wall or corner is affecting the perceived loudness of one channel, I would ever so slightly adjust the gain for that channel, either at the power amp, or the balance control. Acoustical treatment, sound absorbing panels could also be tried, others can chime in on that.

The ONLY way to deal with any perceived loudness difference with SDA's is acoustically. If you try to do it electrically you will mess the "SDA" effect because the SDA signal is the difference between L&R. If you change the input balance you change the SDA signal. If you try to use any type of stereo equalization (mono wouldn't matter) it too will mess with the SDA signal. SDA's have "built-in" toe in, the difference in distance from the tweeters voice coil and main drivers voice coil to your ear. So anyhow my experimentation shows that in my particular set up I can easily hear 1/4" of "misalignment" from parallel. Toe in of 1/8" at a time has the effect of extending the soundstage further L&R, to the point that at about 1" (at a listening distance of 12') you have sounds coming from behind you. I'm going to try some toe out tonight and note the changes. I might as well have some fun with it, it takes me about an hour to get them back to perfect alignment again!

I beg to differ, since I've made a slight adjustment to the right channel gain on my 2As. The right speaker is 5' from a corner, however I have a large antique desk that is within 2' of the right speaker tucked into that corner. Reflections off the desk made the right channel appear louder. The slight gain adjustment compensated for this, with no degradation of the crosstalk cancellation.
If you feel toe-in will correct your problems, knock yourself out.

Well I suppose if it sounds good to you that way, "than knock yourself out". I don't have an issue, was just doing some experimentation and sharing the results here. Have you done any measurements to verify your situation, or are you trusting your ears? If a slight gain adjustment fixes your problem to your satisfaction, than that's great, I'm sure there is a lot of acoustical issues going on if your listening room is lopsided like that. Just for fun equalize the gain and toe one side in 1/8" and see what happens.

westmassguy

I've used the MCACC calibration built into my Pioneer Elite, and also via an SPL Meter.
Both required a 1db decrease for the right channel.

TennMan

This may be slightly off topic since it's not about toeing but it is along the same lines.

For Christmas I picked up a cheap Yamaha AVR to experiment with a home theater setup. I first connected it to my 2B-TLs as I would for 2-channel listening with me manually adjusting everything for me sitting in the center of the sofa. sitting in the center of my sofa is my normal 2-channel listening position. The Yamaha does a good job at 100 watts per channel but the bass isn't as defined as it is with my Adcom 450 preamp and 555 power amp. The SDA effect was what I normally have with my Adcom setup.

Next I added a small center speaker, then I used the Yamaha calibration system to automatically adjust everything for me sitting on the left side of the sofa where I normally sit when watching TV. When the calibration process was complete the Yamaha had the sound appearing to come from the center when listening to a CD with some SDA seeming to come from the left side and a small amount from the right. Not near as good as the Adcom setup but actually I didn't expect any SDA sitting that far out of center.

Then I selected a TV channel that had 5.1 Dolby sound. Wow! Was I surprised at how much I could hear coming from outside the width of the 2Bs. I'm reluctant to call it an SDA effect, but whatever you want to call it, was as good, or probably better, than the SDA effect I normally get when my 2Bs are setup correctly with my Adcom gear. Even though I'm sitting way out of the center of the equidistant triangle on one end of my sofa, the sound wraps way around to both sides of the room equally.

I wasn't expecting much from a cheap AVR connected to my 2Bs without rear speakers. I knew Dolby 5.1 could enhance special effects but without rear speakers I was expecting the sound to stay between the speakers. I was pleasantly surprised by the big sound stage I now have for watching TV and movies.