Turning normal speakers into SDA’s

skrol

mhardy6647 wrote: »

skrol wrote: »

That's it! I used to have a subscription to "Audio" and that article got me started playing with speaker arrays and phasing. I remember the guy with the clarinet behind the sofa.

Really cool about Mathew Polk and the LSi9 SDA too.

In case you didn't know it (and in case you might be interested), virtually every Audio issue ever published (as well as those of its predecssor, Audio Engineering) is available (PDF) thanks to https://www.americanradiohistory.com/Audio-Magazine.htm

Audio, IMO, was the best of the lot in terms of consumer-oriented hifi periodicals.

They also have expanding collections of scans of Stereo Review and High Fidelity -- as well as tonnes of other stuff.

Cool, thanks for the info.

skrol

I don't recall when I joined but the profile info says 2003 but I think it could have been before then. Anyway, I turned 52 today so I would have been 37 in 2003. However, I've been a Polkie since before owning my first set in 1991. Come to think of it, I had installed Polk speaker in my car in 1990 (1990 Dodge Daytons ES V6).

K_M

Did not read this whole thread, but Matt Polk did exactly this with 2 sets of Lsi9's in his house, remember reading a thread about it. (edit, see mentioned now..in thread..also)

We tried the same thing with 2 sets of them also, and simply disconnected the tweeter on the Dimensional pair, and it sounded quite good as far as the SDA sound goes.

Having "real" SDA speakers also, but not in same house, it would be hard to compare directly, but seemed like it worked just as well from memory.

There are a few more details, like a resistor used also but in essence it is very similar to the "Hafler" circuit from years ago, that creates a pseudo surround or ambiance effect.

We did ours totally passive, but after a few weeks simply got tired of it, and moved the 2nd pair back to their original location, not due to lack of good SDA sound, but it took up too much room for 2 pairs next to each other.

mlistens03

Apparently my comment yesterday didn’t ever get posted? Sorry...
Replies in bold.

scubalab wrote: »

Micah - I admire and salute your ambition with this experiment! My daughter is your age... I can't imagine her ever being this inquisitive about re-engineering something! I guess her interests are elsewhere and just don't quite align with this hobby.
Same with most of my friends.
Kudos also to Ken S. for all the tips and support he's given you and not being a naysayer. I think it's very cool that you are 'experimenting' and hope you hit on something that sounds amazing to you!
Agreed, thanks so much Ken, and everyone else who has encouraged and helped me!
Regarding the Polkfests... to my knowledge, they have somewhat fizzled out in recent years, but in their heyday, I believe they were held at or near Polk's HQ in the Baltimore area. More recently, I think forum members still try to keep the tradition alive by hosting get-togethers at their homes. One of these days, I hope to get to one.
Good to know. I’d love to make it to one, but they all seem to be half way across the country.
Some of the best advice I've gotten has come from the great folks on this forum. However, I agree wholeheartedly with your dad with the 'you can't be too cautious' stance when it comes to the internet. I'd recommend sharing your hobby with him, letting him see how passionate you are about the hobby and the interest you have in (and the advice you've gotten from) the forum. I'm sure he'd be proud of how maturely you've presented yourself here, and your enthusiasm with the science and engineering in audio.
I agree with him as well, you never can be too safe. However I realize that we aren’t just a bunch of friends here, who all want to help out. I’m still waiting to find someone who I can send some sort of something to, but I don’t got that much to send.
Best of luck with this effort!!

Thanks!

skrol wrote: »

I don't recall when I joined but the profile info says 2003 but I think it could have been before then. Anyway, I turned 52 today so I would have been 37 in 2003. However, I've been a Polkie since before owning my first set in 1991. Come to think of it, I had installed Polk speaker in my car in 1990 (1990 Dodge Daytons ES V6).

Cool. Happy bitrthday!!

K_M wrote: »

Did not read this whole thread, but Matt Polk did exactly this with 2 sets of Lsi9's in his house, remember reading a thread about it. (edit, see mentioned now..in thread..also)

We tried the same thing with 2 sets of them also, and simply disconnected the tweeter on the Dimensional pair, and it sounded quite good as far as the SDA sound goes.

Having "real" SDA speakers also, but not in same house, it would be hard to compare directly, but seemed like it worked just as well from memory.

There are a few more details, like a resistor used also but in essence it is very similar to the "Hafler" circuit from years ago, that creates a pseudo surround or ambiance effect.

We did ours totally passive, but after a few weeks simply got tired of it, and moved the 2nd pair back to their original location, not due to lack of good SDA sound, but it took up too much room for 2 pairs next to each other.

Very cool. Thanks!

mlistens03

So, I’ve got everything setup the way Ken S. Originally suggested, except I’ve got one problem. There is a nice LOUD hum, I’m guessing a ground loop. Any ideas on how to fix it?
Setup like this: Lafayette as phono stage>> Yamaha as pre amp >> Crown >> red terminals on Crown through the 10:1 voltage divider to my Sony.

mlistens03

mlistens03 wrote: »

So, I’ve got everything setup the way Ken S. Originally suggested, except I’ve got one problem. There is a nice LOUD hum, I’m guessing a ground loop. Any ideas on how to fix it?
Setup like this: Lafayette as phono stage>> Yamaha as pre amp >> Crown >> red terminals on Crown through the 10:1 voltage divider to my Sony.

Fixed the ground loop. Just tied the cases of the Sony and Crown together.
Now I’ve got another issue. The sound from the Missions is only the normal stereo information, so no crosstalk canceling, just two sets of speakers. Any ideas?
I didn’t connect the ground wire inside of the RCA cables that I sacrificed to connect the Sony to the 10:1 voltage divider, should I connect them to something, and if so, what? I don’t know what else it could be, if pics would help I could get them to you later, but my tablet camera is doing some weird stuff right now, once I get the camera worked out I’ll post some.

delkal

mlistens03 wrote: »

mlistens03 wrote: »

So, I’ve got everything setup the way Ken S. Originally suggested, except I’ve got one problem. There is a nice LOUD hum, I’m guessing a ground loop. Any ideas on how to fix it?
Setup like this: Lafayette as phono stage>> Yamaha as pre amp >> Crown >> red terminals on Crown through the 10:1 voltage divider to my Sony.

Fixed the ground loop. Just tied the cases of the Sony and Crown together.
Now I’ve got another issue. The sound from the Missions is only the normal stereo information, so no crosstalk canceling, just two sets of speakers. Any ideas?


I didn’t connect the ground wire inside of the RCA cables that I sacrificed to connect the Sony to the 10:1 voltage divider, should I connect them to something, and if so, what? I don’t know what else it could be, if pics would help I could get them to you later, but my tablet camera is doing some weird stuff right now, once I get the camera worked out I’ll post some.

Are you sure its not working? Did you listen to just the SDA speakers with your man speakers unplugged (make sure when you unplug them they don't short)? The way you have this set up with the variable signal out you will probably need to have your SDA amp turned up a lot to come close to the right volume.

The SDA side alone should sound different. You will hardly hear the vocals and just a echoey sound. That I am not sure with Ken's setup what puts the signal out of phase. Then you get it working you might want to experiment with reversing the polarity of the SDA speakers.

Also not all CDs work well with SDA. You need one mastered so there is a big difference in the right and left channels. The Beatles did this a lot and Abbey Road sounds great. Later we were listening to the remastered Pink Floyd Animals and when we started turning up the SDA side we couldn't hear a difference. We were wondering why but when you just listen to the SDA speakers alone you could barely hear anything. Crappy mastering!

On an RCA cable the outside is ground and the inner pin is hot /positive. You didn't have to trash an RCA cable to remove the ground. It would have solved your ground loop problem

Hermitism

skrol wrote: »

Anyway, I turned 52 today so I would have been 37 in 2003.

Happy Birthday!

F1nut

HAPPY BIRTHDAY Skrol

lightman1

Stan the Man! HBD!

F1nut

I think there's a bit of info missing from what Matt Polk did with his LSi9's. They were not just side by side with one wired out of phase. He designed a DSP program for them, so the resulting SDA was an active system.

mhardy6647

F1nut wrote: »

I think there's a bit of info missing from what Matt Polk did with his LSi9's. They were not just side by side with one wired out of phase. He designed a DSP program for them, so the resulting SDA was an active system.

Which does seem, even from my Luddite perspective, to be the future of "SDA technology" -- if there be one

pitdogg2

mhardy6647 wrote: »

F1nut wrote: »

I think there's a bit of info missing from what Matt Polk did with his LSi9's. They were not just side by side with one wired out of phase. He designed a DSP program for them, so the resulting SDA was an active system.

Which does seem, even from my Luddite perspective, to be the future of "SDA technology" -- if there be one

It has been that way since SRT's right?
There's some SDA tech in the soundbars and it's active instead of passive.

mlistens03

delkal wrote: »

mlistens03 wrote: »

mlistens03 wrote: »

So, I’ve got everything setup the way Ken S. Originally suggested, except I’ve got one problem. There is a nice LOUD hum, I’m guessing a ground loop. Any ideas on how to fix it?
Setup like this: Lafayette as phono stage>> Yamaha as pre amp >> Crown >> red terminals on Crown through the 10:1 voltage divider to my Sony.

Fixed the ground loop. Just tied the cases of the Sony and Crown together.
Now I’ve got another issue. The sound from the Missions is only the normal stereo information, so no crosstalk canceling, just two sets of speakers. Any ideas?


I didn’t connect the ground wire inside of the RCA cables that I sacrificed to connect the Sony to the 10:1 voltage divider, should I connect them to something, and if so, what? I don’t know what else it could be, if pics would help I could get them to you later, but my tablet camera is doing some weird stuff right now, once I get the camera worked out I’ll post some.

Are you sure its not working? Did you listen to just the SDA speakers with your man speakers unplugged (make sure when you unplug them they don't short)? The way you have this set up with the variable signal out you will probably need to have your SDA amp turned up a lot to come close to the right volume.

The SDA side alone should sound different. You will hardly hear the vocals and just a echoey sound. That I am not sure with Ken's setup what puts the signal out of phase. Then you get it working you might want to experiment with reversing the polarity of the SDA speakers.

Also not all CDs work well with SDA. You need one mastered so there is a big difference in the right and left channels. The Beatles did this a lot and Abbey Road sounds great. Later we were listening to the remastered Pink Floyd Animals and when we started turning up the SDA side we couldn't hear a difference. We were wondering why but when you just listen to the SDA speakers alone you could barely hear anything. Crappy mastering!

On an RCA cable the outside is ground and the inner pin is hot /positive. You didn't have to trash an RCA cable to remove the ground. It would have solved your ground loop problem

I was using my Beatles Let It Be record, specifically side two, and that first song there is absolutely nothing in the middle, but there was also no cancellation when I turned balance all the way to the left or right. I did wire the dimensional speakers out of phase, but it still seemed like there was just another speaker playing on the opposite side.
I didn’t, however, put them right next to each other, I set them on top of each other. Could that be my issue?

mlistens03

I trashed an RCA cable so that I could connect it to my bread board, I didn’t want to sacrifice some other component for RCA terminals. It was generic anyway, so I don’t care.
I just cut off the end, and then stripped the outside and inside wires, then plugged the inside into the resistors and cut off the ground wire that wasn’t inside the insulation. The ground is still there, just not connected to anything.

VR3

I believe part of your problem is the one speaker. Being on top of the other. Should be side by side

mhardy6647

FWIW, someone (not me -- no affiliation! ) is sellin' one of Lafayette's morphs of a passive 4-channel adaptor (Dynaquad ambience extraction workalike) on good ol' eBAY even as I am typing this

https://www.ebay.com/itm/Vintage-LaFayette-4-Channel-Decoder/173511470188?hash=item286616ec6c:g:LckAAOSw83dbjEzo

mlistens03

VR3 wrote: »

I believe part of your problem is the one speaker. Being on top of the other. Should be side by side

I think this was the issue. I have it set up side by side now, and there’s some cancelation going on for sure.
One thing I realized just now I saw that my Sony has some processing circuitry in it, and that gives the audio a slight delay, so I’m gonna try it with my Technics, because there’s no processing at all in it.

mlistens03

Ok, so with a little bit of tweaking, and fairly poor setup, it sounds better than I could’ve every hoped. the sound stage is no where near as wide as SDA’s, hitting its limits around a foot outside of the speakers, but within that space it is mind boggling. True pin point accuracy. With the CRS’s (granted, I’ve never had them setup well with an actual SDA cable), there is no where near as much accuracy and pin point... uh, pinpoint-ness. It has brightened the LSi’s significantly, so I’ll have to tone back the treble a bit, and I’ll have to tweak setup, find the best listening spot, and a heckuva lot more, but first results are certainly promising.
Updates as things progress.
Micah

xschop

It's a good thing you didn't place an order at Mouser. This would be a year-long endeavor for sure. Great job. Keep on pluggin' away.

ken brydson

mlistens03 wrote: »

Ok, so with a little bit of tweaking, and fairly poor setup, it sounds better than I could’ve every hoped. the sound stage is no where near as wide as SDA’s, hitting its limits around a foot outside of the speakers, but within that space it is mind boggling. True pin point accuracy. With the CRS’s (granted, I’ve never had them setup well with an actual SDA cable), there is no where near as much accuracy and pin point... uh, pinpoint-ness. It has brightened the LSi’s significantly, so I’ll have to tone back the treble a bit, and I’ll have to tweak setup, find the best listening spot, and a heckuva lot more, but first results are certainly promising.
Updates as things progress.
Micah

Better than you hoped but comparing them to your CRS's that you say aren't set up correctly and no cable? You coulda saved time and energy on those if you want to hear SDA's....

mlistens03

Ive heard SDA’s, but I don’t have a SDA cable, and I wanted to do this as an experiment. I think the CRS’s will be better setup better. But, with the CRS’s setup decently, this sounds better.
And, I was expecting very little, so I would be ecstatic if I got a lot, and fine if I didn’t. And I got a lot, a lot more than I was expecting.
I still have yet to adjust placement and such, but so far, it is working very well.

F1nut

Without the SDA cable the CRS are most definitely not set up decently.

mlistens03

F1nut wrote: »

Without the SDA cable the CRS are most definitely not set up decently.

I used my own cable, but it came in around 4 ohms resistance, so there was at least some SDA effect. Like I said, decently, and that is still a bit of a stretch.

mlistens03

My dad wants his Boston speakers back, so I’m gonna enjoy one last album, and then dismantle this system. Everything will be stored, and experimentation is not, done, simply being put on hold.
Thanks all for your help, it was very useful, and I had a lot of fun building this.
Micah

TennMan

I just read this entire thread. I really enjoyed it because I like to experiment.

A few years ago when I suggested converting my 10Bs to SDAs I got laughed at and I was told by several members here that it wouldn't work. After explaining why I thought it would work using parts from my CRS+, I believe it was F1 that agreed with me that it should work so I moved ahead with the project. The SDA-10Bs sounded great. Good SDA sound and more bass than my CRS+. I used them for about 2 years before finding a pair of 2Bs that that have slightly better bass than the SDA-10Bs. Someone called the SDA-10Bs mini 2Bs. I agree with that.

If I were a cabinet maker I would make a pair of wide 2Bs that would have the same driver spacing as the CRS+ while keeping the same cabinet volume as the 2Bs and see what the result would be. Since I don't have the woodworking tools it will probably never happen.

pitdogg2

You would have mini SRS2. Wider front baffle would widen the stage more than likely. Everybody says the SRS2 has a huge soundstage.

TennMan

pitdogg2 wrote: »

You would have mini SRS2. Wider front baffle would widen the stage more than likely. Everybody says the SRS2 has a huge soundstage.

That's what I was hoping for. Anything taller than a 2B won't work in my room because the cabinet doors won't open. I think a mini SRS2 would be the ideal speaker for me.

xschop

TennMan wrote: »

I just read this entire thread. I really enjoyed it because I like to experiment.

A few years ago when I suggested converting my 10Bs to SDAs I got laughed at and I was told by several members here that it wouldn't work. After explaining why I thought it would work using parts from my CRS+, I believe it was F1 that agreed with me that it should work so I moved ahead with the project. The SDA-10Bs sounded great. Good SDA sound and more bass than my CRS+. I used them for about 2 years before finding a pair of 2Bs that that have slightly better bass than the SDA-10Bs. Someone called the SDA-10Bs mini 2Bs. I agree with that.

If I were a cabinet maker I would make a pair of wide 2Bs that would have the same driver spacing as the CRS+ while keeping the same cabinet volume as the 2Bs and see what the result would be. Since I don't have the woodworking tools it will probably never happen.

Hi Tenn, good to hear from you. If I run across another rough set of monitor 10's, I'll experiment with another set of CRS+ crossovers and put the drivers in CRS arrangement on the back side while plugging the front mw/tweet holes.

TennMan

Interesting. Hope you find some 10's to experiment with. Keep us posted.