Best DIY speaker type (and radiation pattern) for listening to podcasts and audio books in a large room?

[Naughtius]

I spend a lot of time in my kitchen- and living room listening to podcasts and audio books and would like to build a dedicated speaker for the purpose, prioritizing clarity.

I have a set of dipoles at one end of the room, but listening to those on the other end presents me with a 'fuzzy wall of sound', where I feel like I'd prefer a point source in the center of the room (hanging from the ceiling?). I've seen dodecahedron speakers used as point sources for acoustics measurements, but am unsure what would happen with those at the higher frequencies when the drivers would start beaming. I also don't think I'd need the vertical channels in this case? Or would it be wiser to keep those to keep it as a proper point source?

Another idea would be half of one of those, stuck to the ceiling. I feel that would give less ceiling reflections, but would also place the source quite high, where more towards ear level seems preferable from an experience standpoint.

I'm not sure where to take this yet, but would love to brainstorm with you all for a bit!
- David

 

[Naughtius]

Current concept is an "icosidodecahedron" with 12 Dayton Audio PS95-8 woofers, to be hung from the ceiling.

Should get me an omnidirectional response up to ~4k, though I'm unsure what would happen beyond that. The angle between the speakers would be 63°, so that would match the green line in the graph below? I'm assuming I'd simply have peaks and dips in the treble depending on where I'm standing? Would there be comb filtering from the overlapping parts of their radiation patterns? And would that be noticeable?

 

[staticV3]

If in-ceiling is an option, then I think a single flush-mounted Coax speaker like this would make most sense:

KEF Ci200RR-THX In-ceiling/In-Wall Speaker Review

This is a review and detailed measurements of the KEF Ci200RR-THX in-ceiling/in-wall speaker. It was kindly sent to me by a member and costs US $999.99. Speaker has a luxurious feeling rubberized paint outside of the driver. Alas, as you see, it is a dust magnet. Fortunately you would cover the...

www.audiosciencereview.com

 

[Naughtius]

If in-ceiling is an option, then I think a single flush-mounted Coax speaker like this would make most sense

That looks incredible for an in-ceiling speaker! My ceiling is solid concrete though, so that wouldn't be an option. I'd have needed multiple of them to avoid being 'out of range' of the higher frequencies right?

 

[staticV3]

I'd have needed multiple of them to avoid being 'out of range' of the higher frequencies right?

Depends on the ceiling height, your own height at MLP, and your distance from the speaker I guess.

 

[kemmler3D]

Would there be comb filtering from the overlapping parts of their radiation patterns? And would that be noticeable?

Yes, and probably.

If dipole gives you too much diffuse / "wall of sound" effect, then omni (especially true omni) is probably going to be even worse in that regard.

If you want point source and a sharply defined source of sound, you should consider coaxial drivers and traditional box speaker designs. As a DIY job, sticking a KEF Uni-Q coax driver in a box (or the ceiling) should be pretty feasible, but there are cheaper options. (I wrote this before I read @staticV3 's comment, so I concur)

Pseudo-spherical omni speakers (like the one you shared an image of) are interesting, but the main use case I've seen for them is making acoustic measurements, not listening.

 

[Naughtius]

Yes, and probably.

If dipole gives you too much diffuse / "wall of sound" effect, then omni (especially true omni) is probably going to be even worse in that regard.

If you want point source and a sharply defined source of sound, you should consider coaxial drivers and traditional box speaker designs. As a DIY job, sticking a KEF Uni-Q coax driver in a box (or the ceiling) should be pretty feasible, but there are cheaper options. (I wrote this before I read @staticV3 's comment, so I concur)

Pseudo-spherical omni speakers (like the one you shared an image of) are interesting, but the main use case I've seen for them is making acoustic measurements, not listening.

Hmm, that could be a bit annoying. I could make a prototype with some cheaper drivers and see how bad it is.

By the time the dipoles have reached the other side of the room they've bounced all over the place, from the front as well as the back of the speakers. The main upside about the image I shared is that I'd be able to hang it in the middle of the living space, quite far from any walls. I'd hope this shorter path from the center to the kitchen / sofa / dining table (which are all spread around the space) would aid in clarity.

The room itself is 5.5 by 10 by 2.8 meters - I can make a map tomorrow to show some more details - but having one speaker in the ceiling in the middle of the room puts my ears 75° off axis standing all the way on the edge.

And, there is the D-12 from Design Acoustics (though about 50 years old by now):

I'd be open for other ways to make an omnidirectional solution for this problem, not making a pseudo-spherical like this, though this seemed like the simplest solution!

 

[kemmler3D]

Hmm, that could be a bit annoying. I could make a prototype with some cheaper drivers and see how bad it is.

By the time the dipoles have reached the other side of the room they've bounced all over the place, from the front as well as the back of the speakers. The main upside about the image I shared is that I'd be able to hang it in the middle of the living space, quite far from any walls. I'd hope this shorter path from the center to the kitchen / sofa / dining table (which are all spread around the space) would aid in clarity.

The room itself is 5.5 by 10 by 2.8 meters - I can make a map tomorrow to show some more details - but having one speaker in the ceiling in the middle of the room puts my ears 75° off axis standing all the way on the edge.

And, there is the D-12 from Design Acoustics (though about 50 years old by now):
View attachment 351405

I'd be open for other ways to make an omnidirectional solution for this problem, not making a pseudo-spherical like this, though this seemed like the simplest solution!

I guess I should ask - it sounds like you don't have any fixed / main listening position? If you're constantly moving around the room then I'd say omni makes sense. That said, I hope you are very confident in your woodworking skills, as the construction of such a speaker will be quite a thing.

Also, wiring up 12 drivers is a bit beyond the ordinary, so I think you'll need to add some circuitry to present a reasonable load to the amplifier, even if you go active.

Small suggestion: To see if you really like 3D omnidirectional sound as conceived here, maybe put an Apple Homepod in the intended location of this speaker and see how it sounds. It's relatively well-regarded as a lifestyle speaker and it has a 2D omni pattern. You can probably find a used one for pretty cheap, try it out, and sell it on for what you paid.

 

[Naughtius]

I guess I should ask - it sounds like you don't have any fixed / main listening position? If you're constantly moving around the room then I'd say omni makes sense. That said, I hope you are very confident in your woodworking skills, as the construction of such a speaker will be quite a thing.

Also, wiring up 12 drivers is a bit beyond the ordinary, so I think you'll need to add some circuitry to present a reasonable load to the amplifier, even if you go active.

Small suggestion: To see if you really like 3D omnidirectional sound as conceived here, maybe put an Apple Homepod in the intended location of this speaker and see how it sounds. It's relatively well-regarded as a lifestyle speaker and it has a 2D omni pattern. You can probably find a used one for pretty cheap, try it out, and sell it on for what you paid.

That's correct - I am moving around a lot. It would be great having clear sound walking around the entire space! And my woodworking skills aren't too great, but my CNC router is able to solve a lot of that.

I was imagining wiring 3 in series, and paralleling these 4 times. With 8 ohm speakers that should give me about a 6 ohm load. I don't think that would be a problem. I would probably need a load of DSP to sound balanced, but I'm pretty confident being able to solve that part.

Great tip on the apple homepod! The review on here shows great directivity up to 15kHz (which I'm not sure I'm still able to hear). I'll see if I can find one second hand around here.

 

[tmuikku]

Clear sound all around the space is only with headphones Or perhaps multiple, narrow coverage speakers all playing mono sound and all pointed/optimized for each work/hangout area. If you strategically position the speakers close to area's you spend time you could keep overall volume level down, you'd always hear the closest one with high clarity.

If you put single speaker, no matter DI, into one corner of a room the sound is less clear if you stand on the other due to room reflections, if you have two speakers playing phantom center sound it's even worse I think. And the more so if you have an omni speaker, clear sound would be available only quite close to the speaker. I would avoid omnis here, although idea of smooth DI is the key which omni could also fulfil. If it's center of room speaker, perhaps omni is only option then.

If it is single speaker I'd make highly directional speaker with nice DI, rather big one. The sound stays as clear as it could through out the space due to increased direct / room sound ratio, which one can further optimize by toe-in. Omni doesn't allow utilization of toe-in and thus requires always having it rather close to you for high clarity (D/R).

Directional speaker doesn't mean sound is bad off-axis, all it means sound attenuates off-axis. If power response is fine, and most axi toward room are close to power response (flat DI), then the sound is the same everywhere just like with (ideal) omni, although omni would be as loud to any direction, while directional speaker gets less loud the more off-axis, which means room sound can be reduced, which means more clarity basically. If DI is bad, then power and axial response do not match and sound changes with listening position.

If you have fine acoustics, iow it's not exessively noisy environment, perhaps omnis are just fine, any speaker. But if search is for more clarity, then I'd try and get more clarity and utilizing directivity would provide. Also, try just one speaker playing in mono for speech, should increase clarity compared to stereo speakers. Stereo has clarity for phantom center only when you are ~equidistant to both speakers. It's also important to consider acoustics at home, if there is relatively much reflective surface there is likely flutter echo issue which is really bad for intelligibility, in which case perhaps look to reduce that. Nice acoustics helps everyday life, less noisy environment is less stressful.

ps. clarity is highly relative perceptually, I mean small increase in clarity can be huge improvement for some, while others never think about clarity at all, just put the tv louder to hear better

 

[Naughtius]

Clear sound all around the space is only with headphones Or perhaps multiple, narrow coverage speakers all playing mono sound pointed to your work area. You'd always hear the closest one. If you strategically position the speakers close to your working area's you could keep level down, clarity high.

If you put single speaker, no matter DI, into one corner of a room the sound is less clear if you stand on the other due to room reflections. The more so if you have an omni speaker, clear sound would be available only quite close to the speaker. I would avoid omnis here, altough idea of smooth DI is the key which omni could also fulfil.

I'd make highly directional speaker with nice DI, rather big one. The sound stays as clear as it could through out the space due to increased direct / room sound ratio, which one can further optimize by toe-in. Omni doesn't allow utilization of toe-in and thus requires always having it rather close to you for high clarity (D/R).

Directional speaker doesn't mean sound is bad off-axis, all it means sound attenuates off-axis. If power response is fine, and most axi toward room are close to power response (flat DI), then the sound is the same everywhere just like with (ideal) omni, although omni would be as loud to any direction, while directional speaker gets less loud the more off-axis, which means room sound can be reduced, which means more clarity basically. If DI is bad, then power and axial response do not match and sound changes with listening position.

If you have fine acoustics, iow it's not exessively noisy environment, perhaps omnis are just fine, any speaker. But if search is for more clarity, then I'd try and get more clarity and utilizing directivity would provide.

Good point on the direct / reflected sound ratio. There's definitely more energy coming from an omni than there is from the dipoles here - and though I'd be twice as close to the ceiling hung omni on the far end of the room, compared to the dipoles, that would theoretically cancel each other out end leave me with the same ratio.

I've also figured out why no one seems to listen to these dodecahedron speakers. From some of the spec sheets:

Their polar plots get close to 10dB bumps from ~4kHz onwards. So the comb filtering does seem quite significant. These speakers are around 30cm in diameter - making one 15cm in diameter would get me to 8kHz before it starts acting like this, but that wouldn't leave a lot of room for the low end...

Being curious about the homepod's excellent directivity I took a look at a disassembly video. Does anyone understand what's going on with these tweeters? Where are they firing too / from?

First step I'm planning is borrowing one, and seeing if I would indeed like this kind of sound for this purpose.

 

[617]

I am designing an omni speaker similar to what you have been looking at, but it requires the use of much smaller, wide dispersion drivers to work well.

For speech clarity you don't want wide dispersion, you want limited dispersion covering the area of interest. A PA style speaker or cardioid is what you want. Cardioids are expensive and PA horns are large.

I would highly recommend the Sonos systems, my friends have one in their kitchen and I doubt you'll do better for podcasts. They are far more sophisticated from a technological perspective than any hifi speaker.

 

[Golf]

Nice pic!

 

[Naughtius]

I am designing an omni speaker similar to what you have been looking at, but it requires the use of much smaller, wide dispersion drivers to work well.

For speech clarity you don't want wide dispersion, you want limited dispersion covering the area of interest. A PA style speaker or cardioid is what you want. Cardioids are expensive and PA horns are large.

I would highly recommend the Sonos systems, my friends have one in their kitchen and I doubt you'll do better for podcasts. They are far more sophisticated from a technological perspective than any hifi speaker.

Can you share some more details on what you're working on? Curious to see!

The problem I'm facing is that my living room / kitchen island / dining table is all area of interest... Here's a crude drawing of the space:

Ideally I'd have clear sound at the sofa, beanbag, kitchen, dining table, and desk. The desk is worst now, being at the side of the dipoles. My plan would be hanging one omni between the dining table and listening chair.

And (besides the fact that that would mean purchasing speakers from my employer) I don't have wifi at home, so am limited to Bluetooth and wired options!

 

[D!sco]

I think a high quality mono solution would be best. You can easily use single drivers to fill your listening space, localization and stereo imaging isn't important for podcasts and other talk shows, typically. A quality wideband driver will cover the telephonic vocal range very easily. A small bass box or two could easily fill in the lows of a simple 3" fullrange driver or similar.

Hell, I'd even think about something silly like the Klipsch Lightbulb for something as simple as podcasts.

 

[Golf]

Just out of »geometrical curiosity«:

I wonder how to construct this shape, as it is a dodecahedron with additional triangles. From an aesthetically standpoint, it looks nicer (smoother and better balanced) than the basic dodecahedron. But again: how to construct it?

 

[kemmler3D]

Just out of »geometrically curiosity«:

I wonder how to construct this shape, as it is a dodecahedron with additional triangles. From an aesthetically standpoint, it looks nicer (smoother and better balanced) than the basic dodecahedron. But again: how to construct it?

I think OP would need to CNC each face separately (or a few at a time) and then glue them together somehow. I think the gluing together is what I'm wondering about.

 

[Golf]

It is even more the technical drawings what I have in mind in the first place. Without them it would be difficult to program any CNC machine

 

[kemmler3D]

Any chance you would 3D print it instead of CNC? For a shape like this I feel like using wood is doing it the hard way. I have seen a few projects that 3D printed a shell in parts, then filled the shell with concrete or plaster to achieve a similar or greater density vs wood.

Of course if you went to 3D printing, you could just make it a sphere with speakers on it, no need for facets at that point.

 

[Duke]

The problem I'm facing is that my living room / kitchen island / dining table is all area of interest... Here's a crude drawing of the space:
View attachment 351545
Ideally I'd have clear sound at the sofa, beanbag, kitchen, dining table, and desk. The desk is worst now, being at the side of the dipoles. My plan would be hanging one omni between the dining table and listening chair.

You see that corner behind the left-hand LX521? From that corner you can illuminate the entire space. I suggest two fairly narrow-pattern prosound-style speakers stacked in that corner. Like maybe a 60-degree pattern horn + 12" or 15" midwoofer. They don't need to have much low end for this application, and the corner will boost what low end they do have. Feed them both a mono signal, aim one at the kitchen area and aim the other at the desk.