My project for the summer is to build a better "lifestyle" speaker. The criteria being it is a single bluetooth enabled speaker meant to be plugged into a power outlet.
My desired outcome is a fun speaker with a big soundstage so overall accuracy is low on my list. Designs that I have built and enjoyed in the past are the Cornu horn and Karlsonator.
Inspiration for this project is the Bose 901 but instead of 2 individual speakers I wanted to include two channels in a single enclosure. The thought being that using room boundary effects will increase the soundstage and provide more of a stereo effect from a single enclosure. To take things a step further I am wondering if I can use corner loading to exaggerate this effect further.
This is more of a discussion starter topic. Looking for feedback, ideas, or recommendations no matter how crazy or out there they might be. Just to reiterate, the intent is a FUN speaker not an accurate one.
My desired outcome is a fun speaker with a big soundstage so overall accuracy is low on my list. Designs that I have built and enjoyed in the past are the Cornu horn and Karlsonator.
Inspiration for this project is the Bose 901 but instead of 2 individual speakers I wanted to include two channels in a single enclosure. The thought being that using room boundary effects will increase the soundstage and provide more of a stereo effect from a single enclosure. To take things a step further I am wondering if I can use corner loading to exaggerate this effect further.
This is more of a discussion starter topic. Looking for feedback, ideas, or recommendations no matter how crazy or out there they might be. Just to reiterate, the intent is a FUN speaker not an accurate one.
I've built a good number of them, but mostly 2-way (tweeter/woofer). I currently own a small fullrange BT version that I did not build.
There is a lot of good info here on the subject:
https://www.diyaudio.com/community/threads/stereophonic-sound-from-a-single-loudspeaker.200040
There is a lot of good info here on the subject:
https://www.diyaudio.com/community/threads/stereophonic-sound-from-a-single-loudspeaker.200040
a bunch here..
I thought the three driver matrix was much better than the four driver, I've never heard a six driver.
https://www.diyaudio.com/community/threads/thoughts-about-single-box-stereo.383290/
I thought the three driver matrix was much better than the four driver, I've never heard a six driver.
https://www.diyaudio.com/community/threads/thoughts-about-single-box-stereo.383290/
Yeah, I'd like to work on a 3 speaker matrix. But for a fun music box it isn't really needed. Stereo in one box works OK if it's fairly wide.
Lot's of good info, I'll have to do some reading. Thanks everyone for the links.
Looks like my plan to use a Class-D amp may prevent me from passive wiring options. I'd rather not go the multi-channel DSP route due to cost, however, that might open up some interesting opportunities in it's own way.
Looks like my plan to use a Class-D amp may prevent me from passive wiring options. I'd rather not go the multi-channel DSP route due to cost, however, that might open up some interesting opportunities in it's own way.
If I understand it right the six driver will work with class D amps. A lot of drivers to buy, but the bose 901 has a lot of drivers too.. 😁
A lot of small Class-D amps are BTL, meaning that the negative terminal is NOT ground, so it can be difficult to tie them together. Some amps don't mind, other do. That makes the cool passive matrix a bit of a gamble.
I realised recently that the Bose 901 does something clever, which may have been missed:
The precedence effect means we tend to localise sound to wherever the first wavefront arrives from. However, this can be over-powered with level: if a delayed source is louder, our perception may shift towards the delayed source being the source of the sound.
The Bose 901 has 8x drivers firing backwards, which has two effects:
1 - Some directivity control - you won't hear much direct sound from those drivers in the mid-high range.
2 - Much higher ratio of reflected sound than most other speakers.
I suspect (haven't tried it yet) that if someone was to make a Bose 901-style bluetooth speaker with two drivers on the front (L&R) and 8x drivers on the back (4x L and 4x R), and place it a suitable distance from a back wall, a pleasantly "spacious" sound would be achieved.
The last bit is speculation on my part, but IMO the Bose 901 deserves a little more credit than it's given. While not strictly "HiFi" (IMO), it's a good way of achieving that "spacious" sound which divides opinions.
Chris
That's why I added a cycolac horn tweeter to the back of my Advent Maestro floor-standing speakers.
Directly behind the front tweeter, it fires against the wall and adds a pleasent spaciousness to the already fine sound.
Directly behind the front tweeter, it fires against the wall and adds a pleasent spaciousness to the already fine sound.
This was my thinking going into the project. Higher ratio of reflected sound originating from the rear of the speaker to get more width.
Now that I have been learning a bit about matrixing I am at a bit of an end pass on which route to go. Guess I need to break out the foamcore and experiment a bit.
In the real world, and enjoying a concert or any musical event, the instruments played by the orchestra/band, etc., are held in their hands, and out in open air, and basically transmit their sounds throughout the area.
The primary sounds you hear are directly from the instrument(s) to your two ears, and in addition some of their sound is reflected off of the back/side walls of the stage or arena, right?
The milli-seconds of delay of these "reflected" sounds adds to the richness and enjoyment, that is why some venues are held in those "clamshell" theaters.
So to listen to music through only front-facing speakers narrows and focuses the results, essentially limiting that "realistic" aural experience, and its depth.
A bit of a "bottleneck" in other terms.
Makes sense, doesn't it?
Most people are satisfied with that, and that's fine.
While my Advents are good satisfying speakers, with the addition of a rear-facing tweeter, they've become almost invisible, the depth makes the music become more "alive", and I can imagine the walls of my livingroom disappearing, or moving back, which is quite pleasent.
I can detect more of the room/area/studio that the music is played in.
Backup singers are in the background where they should be, as are instruments.
The "3D effect" is increased.
The primary sounds you hear are directly from the instrument(s) to your two ears, and in addition some of their sound is reflected off of the back/side walls of the stage or arena, right?
The milli-seconds of delay of these "reflected" sounds adds to the richness and enjoyment, that is why some venues are held in those "clamshell" theaters.
So to listen to music through only front-facing speakers narrows and focuses the results, essentially limiting that "realistic" aural experience, and its depth.
A bit of a "bottleneck" in other terms.
Makes sense, doesn't it?
Most people are satisfied with that, and that's fine.
While my Advents are good satisfying speakers, with the addition of a rear-facing tweeter, they've become almost invisible, the depth makes the music become more "alive", and I can imagine the walls of my livingroom disappearing, or moving back, which is quite pleasent.
I can detect more of the room/area/studio that the music is played in.
Backup singers are in the background where they should be, as are instruments.
The "3D effect" is increased.
I'm curious as to how the Mass Fidelity Core works, it uses something called wave field synthesis, and doesn't need to use walls to bounce sound off.
I've wondered if something like a headphone cross feeder applied to to close together drivers would work.
I've wondered if something like a headphone cross feeder applied to to close together drivers would work.
Certain "boom boxes" of yore figured this out; one has a "stereo-wide" control that, when engaged, made the stereo sound image much wider than the physical speaker separation.
Unfortunately, I dont have the exact circuit on hand, but it was done waaay before DSP with its "do anything by entering a few numbers" capability of today.
Probably some passive arrangement that mixed in a band limited and delayed signal from the opposite channel. Aww, heck - https://www.google.com/search?q="stereo+wide"+passive+circuit Click on "images"... There ya go! You can just buy a board that does it.
Unfortunately, I dont have the exact circuit on hand, but it was done waaay before DSP with its "do anything by entering a few numbers" capability of today.
Probably some passive arrangement that mixed in a band limited and delayed signal from the opposite channel. Aww, heck - https://www.google.com/search?q="stereo+wide"+passive+circuit Click on "images"... There ya go! You can just buy a board that does it.
Using the corners cleanly allows the widest natural separation. Using them for effects is another story.
Explore the SRS (Sound Retrieval System) system originally designed by Hughs Aircraft.
It's in many TV sets these days, and was used for in-flight movies, and back in the 1990's a company called New Reality made several home stereo versions - The Vivid3D, I have one and it does enhance separation, adjustable.
https://www.soundonsound.com/reviews/nureality-vivid-3d-stereo-enhancement-system
https://www.ebay.com/itm/354123834522?hash=item52736ce49a:g:alIAAOSwntxis6cd
It's in many TV sets these days, and was used for in-flight movies, and back in the 1990's a company called New Reality made several home stereo versions - The Vivid3D, I have one and it does enhance separation, adjustable.
https://www.soundonsound.com/reviews/nureality-vivid-3d-stereo-enhancement-system
https://www.ebay.com/itm/354123834522?hash=item52736ce49a:g:alIAAOSwntxis6cd
Maybe it's cheating, but: https://addison-electronique.com/en...essor-limiter-and-stereo-expander-2-channels/
You might want to check out the SSS thread. Elias had some good info. It uses reflection from side walls to give the stereo image. I have tried it and it works!
https://www.diyaudio.com/community/threads/stereophonic-sound-from-a-single-loudspeaker.200040/
https://www.diyaudio.com/community/...matrixed-single-stereo-speakers.257110/page-3
http://elias.altervista.org/html/SingleSpeakerStereo.html
Actually, I set two small Karlsonators angled to the side and a central Karlsonator in the middle to test it out before I made a purpose built cabinet - all in foam core of course.
I made mine with 3x TC9FD’s in a ported reflex box with a trapezoid cross section. I used a class AB lunch money chip amp (TDA7298) which allows mixing three channels.
Wired like this:
https://www.diyaudio.com/community/threads/stereophonic-sound-from-a-single-loudspeaker.200040/
https://www.diyaudio.com/community/...matrixed-single-stereo-speakers.257110/page-3
http://elias.altervista.org/html/SingleSpeakerStereo.html
Actually, I set two small Karlsonators angled to the side and a central Karlsonator in the middle to test it out before I made a purpose built cabinet - all in foam core of course.
I made mine with 3x TC9FD’s in a ported reflex box with a trapezoid cross section. I used a class AB lunch money chip amp (TDA7298) which allows mixing three channels.
Wired like this:
Last edited:
https://www.diyaudio.com/community/threads/stereophonic-sound-from-a-single-loudspeaker.200040/
Do you recall your impressions of it? Was it worth the hassle of mixing the channels compared to something like your flat wall mounted MLTL using the same TC9FD?