Four driver matrix sounded like mono with some faint swishing sounds coming out of the side speakers every once in a while.
Vocal intelligibility was better but didn't seem as good as two channel (didn't directly compare). There was some volume variation in voices with 4 driver that I hadn't noticed before, maybe cancellation of some kind in the middle. I think the three driver was better than the 4, more involving than the 4 driver or two channel, but lost too much vocal intelligibility for me. That's my main priority, I like to watch a movie not be yelled at by it. Other people might like the three channel. I have no walls on the sides, but it's hard to imagine the 4 driver doing much with them if they were there, three driver had much more sound out of the sides.
Vocal intelligibility was better but didn't seem as good as two channel (didn't directly compare). There was some volume variation in voices with 4 driver that I hadn't noticed before, maybe cancellation of some kind in the middle. I think the three driver was better than the 4, more involving than the 4 driver or two channel, but lost too much vocal intelligibility for me. That's my main priority, I like to watch a movie not be yelled at by it. Other people might like the three channel. I have no walls on the sides, but it's hard to imagine the 4 driver doing much with them if they were there, three driver had much more sound out of the sides.
Could you describe what the setup was for the four driver matrix?
Actually, I'm not totally clear on what your three drive matrix was either?
Actually, I'm not totally clear on what your three drive matrix was either?
Yes, like here.
https://www.diyaudio.com/community/...ed-single-stereo-speakers.257110/post-3946671
The 4 driver has the center speakers one on top of the other..
https://www.diyaudio.com/community/...ed-single-stereo-speakers.257110/post-3946671
The 4 driver has the center speakers one on top of the other..
Ah yes, I remember those two.
In general, setups where you hook the drivers to a stereo amp in unconventional ways make me a bit uneasy. I’m a bit ignorant of amp tech, but it strikes me that different amps will respond differently to these things, or possible shut down or break.
If nothing else, it puts a bit limitation on driver choices and configurations.
Nonetheless I’m very interested in what results people are getting!
In general, setups where you hook the drivers to a stereo amp in unconventional ways make me a bit uneasy. I’m a bit ignorant of amp tech, but it strikes me that different amps will respond differently to these things, or possible shut down or break.
If nothing else, it puts a bit limitation on driver choices and configurations.
Nonetheless I’m very interested in what results people are getting!
Me too, it seems weird but the amp is cheap and I have others. Now I learned something, so it's worth the risk to me. 🙂
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I think that's my point, though - what did we learn?
I'm assuming that the four driver matrix didn't work as intended. I can't imagine that mono with occasional faint swishes on the side is what this is supposed to do.
(any chance you got the polarity of the side speakers reversed? If so, you would have had the R-L side speaker next to the L speaker, which would cancel out much of the L signal, and vice versa)
I guess you can do a test, by hooking up only one side driver to the two + connections on your amp to see if it really can produce a Difference signal. Depending on your source material it should sound very echo-y, with the center sounds totally cancelled out. For pop music, things like the bass, kick, snare, lead vocals, should be gone, but their reverbs usually will be heard.
And if you have the capacity to pan a mono signal left-to-right (at the source, not with the balance knob on the amp), you SHOULD hear it strongly at left, fading to silence at center, then strongly again (but phase inversed) on the right.
The same should be true for any Sum/Difference matrix.
The six-driver acoustic matrix version posted earlier will probably not have such a clear result - putting two drivers close to one another, each playing a left or right signal with one of them out of phase, probably doesn't completely cancel out the center (the Sum) like an electronic matrix can.
I'm assuming that the four driver matrix didn't work as intended. I can't imagine that mono with occasional faint swishes on the side is what this is supposed to do.
(any chance you got the polarity of the side speakers reversed? If so, you would have had the R-L side speaker next to the L speaker, which would cancel out much of the L signal, and vice versa)
I guess you can do a test, by hooking up only one side driver to the two + connections on your amp to see if it really can produce a Difference signal. Depending on your source material it should sound very echo-y, with the center sounds totally cancelled out. For pop music, things like the bass, kick, snare, lead vocals, should be gone, but their reverbs usually will be heard.
And if you have the capacity to pan a mono signal left-to-right (at the source, not with the balance knob on the amp), you SHOULD hear it strongly at left, fading to silence at center, then strongly again (but phase inversed) on the right.
The same should be true for any Sum/Difference matrix.
The six-driver acoustic matrix version posted earlier will probably not have such a clear result - putting two drivers close to one another, each playing a left or right signal with one of them out of phase, probably doesn't completely cancel out the center (the Sum) like an electronic matrix can.
Hi, pretty sure I hooked it up right. Pretty careful as I didn't want to blow the amp (yet). As I understand it since then looking at the information, in the 4 driver the left side speaker is left signal minus right signal, and the right side speaker is right signal minus left signal. So it makes sense that there would only be swishing sounds. I played a tv show that had no sound out the sides, and figure it must be mono.
The 3 driver matrix is referred to as 0.5 matrix because it only subtracts half the left signal from the right side and half the right signal from the left side, so there's more sound out the sides. If I remember right, with the three driver, they did sound rather echoey on the sides too. I think so.
So that's what I learned.
The 3 driver matrix is referred to as 0.5 matrix because it only subtracts half the left signal from the right side and half the right signal from the left side, so there's more sound out the sides. If I remember right, with the three driver, they did sound rather echoey on the sides too. I think so.
So that's what I learned.
Ah, so you were listening to a Mono TV source. No wonder it sounded like mono.
The swishing you heard on the sides could well have been slight differences in left and right, either from analog imperfections or digital compression artifacts.
The swishing you heard on the sides could well have been slight differences in left and right, either from analog imperfections or digital compression artifacts.
You don't seem to be getting it, but instead are insisting on your own random theory involving me ****ing it up. lol.
The differences in four driver were not artifacts, simply the difference in audio between the left and right channels, which turns out was minimal in stereo, and non existent in mono. Because in mono the same thing is on both channels.
In the four driver, as I said, the two middle drivers are one on top of each other, one is the left signal one is the right signal, so = mono.
It's not that difficult, but I guess that's why I'm happy I did it, instead of just reading something about somebody doing it. Perhaps the confusion is caused by my terminology "swishing noises". It's meant as a general description.
The differences in four driver were not artifacts, simply the difference in audio between the left and right channels, which turns out was minimal in stereo, and non existent in mono. Because in mono the same thing is on both channels.
In the four driver, as I said, the two middle drivers are one on top of each other, one is the left signal one is the right signal, so = mono.
It's not that difficult, but I guess that's why I'm happy I did it, instead of just reading something about somebody doing it. Perhaps the confusion is caused by my terminology "swishing noises". It's meant as a general description.
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Thank you nandappe, it is a sony str K700
link to pdf service manual
http://sportsbil.com/sony/STR/STR-K/STR-K700_v1.0.pdf
outputs on page 21
link to pdf service manual
http://sportsbil.com/sony/STR/STR-K/STR-K700_v1.0.pdf
outputs on page 21
No sorry, that was not my intention. My point was mainly that these matrix solutions using amplifier hacks are finicky at best. In many scenarios they simply don't work right.You don't seem to be getting it, but instead are insisting on your own random theory involving me ****ing it up. lol.
The differences in four driver were not artifacts, simply the difference in audio between the left and right channels, which turns out was minimal in stereo, and non existent in mono. Because in mono the same thing is on both channels.
In the four driver, as I said, the two middle drivers are one on top of each other, one is the left signal one is the right signal, so = mono.
It's not that difficult, but I guess that's why I'm happy I did it, instead of just reading something about somebody doing it. Perhaps the confusion is caused by my terminology "swishing noises". It's meant as a general description.
From your description of your results, it just didn't seem like they sounded the way I think those designs are intended to sound. Who knows, it might simply comes down to descriptive word choices.
I did misread you about the mono TV - I got the impression that you only tried it out with a mono source, not some of each.
As for your amp, I peeked at the service manual, but I don't have the skills to determine if it's a balanced amp or not. Are home theater receivers typically balanced? All the speaker terminals do share a common negative connection, does that mean anything here?
I'm sorry too, I can see how you thought that from my bad descriptions. All I can say about the balanced/unbalanced is that I'm not familiar enough with amp topologies to be able to state with authority what unbalanced and balanced is, beyond a general understanding of the term either. In the Master Nagaoka thread the only amps that didn't work were BTL class D ones.
Beyond that, both the 4 and three drivers appear to me work the way they're supposed to, it's just that the 4 driver doesn't work all that great really. I did like the three driver, but two channel is still better imo. There are a lot more people building the three driver than the 4, if the amount of pictures that appear in internet searching are an indication.
Beyond that, both the 4 and three drivers appear to me work the way they're supposed to, it's just that the 4 driver doesn't work all that great really. I did like the three driver, but two channel is still better imo. There are a lot more people building the three driver than the 4, if the amount of pictures that appear in internet searching are an indication.
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Back to topic, gentlemen?
Simple single box stereo, in a sense similar to the Japanese boom boxes of the late 70s / 80s, NOT the later ghetto blasters?
And of course, their fixed variations, mains powered, pleasing sound level and rendition?
NOT audiophile grade...
And yes, should be possible to make yourself if you are able to do it
Simple single box stereo, in a sense similar to the Japanese boom boxes of the late 70s / 80s, NOT the later ghetto blasters?
And of course, their fixed variations, mains powered, pleasing sound level and rendition?
NOT audiophile grade...
And yes, should be possible to make yourself if you are able to do it
About a month on radio, a lot less on tape.
Okay for a picnic.
Mine had 8 D cells, Sharp GF-6060...
Okay for a picnic.
Mine had 8 D cells, Sharp GF-6060...
I'm curious about any box that attempts to produce a reasonably wide stereo image without needing any external speakers.
I guess boomboxes might qualify, but generally they just use regular Left and Right speakers, placed something like a foot apart.
It's not often they try to widen the stereo image past that width (other than detachable speakers), is it?
There's also things like the Bose Wave units. Do they use any stereo widening trickery?
Then there are countless bluetooth speakers, but they are mostly produced using today's mindset, where stereo has become a bit of an afterthought, if used at all.
A Google search came up with the Riva Stadium. Three woofers, three tweeters, four passive radiators.
Presumably can play below 55Hz, and at 106db, in a pretty tiny box. It uses their patented "Trillium" system for one box stereo. Looks a lot like a version of the familiar 3-driver layout.
I guess boomboxes might qualify, but generally they just use regular Left and Right speakers, placed something like a foot apart.
It's not often they try to widen the stereo image past that width (other than detachable speakers), is it?
There's also things like the Bose Wave units. Do they use any stereo widening trickery?
Then there are countless bluetooth speakers, but they are mostly produced using today's mindset, where stereo has become a bit of an afterthought, if used at all.
A Google search came up with the Riva Stadium. Three woofers, three tweeters, four passive radiators.
Presumably can play below 55Hz, and at 106db, in a pretty tiny box. It uses their patented "Trillium" system for one box stereo. Looks a lot like a version of the familiar 3-driver layout.
Bose had a labyrinth resonator on the Wave units, I think.
You can angle the speakers a bit inside the box, and maybe increase the center distance, but there are many variations.
For a decent house, about 10W / channel is enough, and stereo imaging will be zero if you are in the living room and the box is in the kitchen...
You can angle the speakers a bit inside the box, and maybe increase the center distance, but there are many variations.
For a decent house, about 10W / channel is enough, and stereo imaging will be zero if you are in the living room and the box is in the kitchen...
The labyrinth on a Bose Wave is purely for bass extension, I think.
An inwards/outwards angle of drivers could be seen as a direct/reflected sound mix compromise. You can go reflected to the extreme, and only have drivers facing fully sideways. Or even have them mainly facing rearwards, to reflect off a back wall - a bit like a stereo Bose 901. That would work in some circumstances, but relying on reflected sound too much is a bad idea, since you're entirely dependent on where the walls are, and what the wall surfaces are like.
Increasing center distance is always a positive improvement. Sound bars generally use driver distance as their only helper for stereo width. But a wide sound bar shape isn't usually something we'd want sitting in the middle of a living room!
An inwards/outwards angle of drivers could be seen as a direct/reflected sound mix compromise. You can go reflected to the extreme, and only have drivers facing fully sideways. Or even have them mainly facing rearwards, to reflect off a back wall - a bit like a stereo Bose 901. That would work in some circumstances, but relying on reflected sound too much is a bad idea, since you're entirely dependent on where the walls are, and what the wall surfaces are like.
Increasing center distance is always a positive improvement. Sound bars generally use driver distance as their only helper for stereo width. But a wide sound bar shape isn't usually something we'd want sitting in the middle of a living room!
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