Cardioid Loudspeakers - Are they worth it?

[ferrellms]

Wouldn’t a cardioid speaker be rather useless in a home theatre setup where you have subs? Seems like a lot of them have pretty high distortion in the 150 and under range anyway.
I’d cross them over to subs just like my towers. So if you are using subs with them do they still benefit?

Wouldn’t a cardioid speaker be rather useless in a home theatre setup where you have subs? Seems like a lot of them have pretty high distortion in the 150 and under range anyway.
I’d cross them over to subs just like my towers. So if you are using subs with them do they still benefit?

If my experience with Kii 3 is any indication, subwoofers are an expensive and unneeded hassle. In a big home theater, maybe, but the BXT extensions are also cardioid. Cardiod subwoofers are common in pro applications, and just work better if you do need a subwoofer.

 

[dasdoing]

An intriguing test reveals the measurement of a freestanding big horn with coaxial behavior, as well as measurements with 1, 2, and 3 boundaries. Interestingly, the test also demonstrates that coaxial behavior is not advantageous at subwoofer frequencies, as the boundaries prove to be more useful.

How Do Boundaries Affect Loudspeakers?

Can a room boundary be a "tool of the trade" for the audio practitioner? This study will provide some insight on how boundaries affect loudspeakers.

www.prosoundtraining.com

 

[Goldhamster916]

Does the side/back cancelling nature of cardioid designs actually reduce what can be heard by neighbors to a significant degree? Has anyone tested if cardioid designs are significantly less audible in the non listening room vs. Non cardioid designs?

I appreciate any reply!

 

[Keith_W]

Does the side/back cancelling nature of cardioid designs actually reduce what can be heard by neighbors to a significant degree? Has anyone tested if cardioid designs are significantly less audible in the non listening room vs. Non cardioid designs?

The answer in theory should be "yes". What your neighbours hear is the total sound power radiated into the room. Since cardioids send a greater proportion of that sound power into the listening window (i.e. towards the listener), you need less sound power to achieve the same SPL at the listening position.

 

[Absolute]

Does the side/back cancelling nature of cardioid designs actually reduce what can be heard by neighbors to a significant degree? Has anyone tested if cardioid designs are significantly less audible in the non listening room vs. Non cardioid designs?

I appreciate any reply!

No. One could argue theoretically, but in reality it's the bass that's most annoying for neighbors and there's no cardioide effect at those frequencies. Not that it would matter anyways as directivity in the sub 100 hz region is irrelevant in small rooms. Our lack of impulse sensitivity in the bass means the sound would have bounced around the room a few times before we could pick up on it, rendering any directivity meaningless. We hear the steady-state modal characteristics of the room/speaker interaction, not the impulse at low frequencies.

I have tested this with Kii Three. Made no difference in the bedroom behind the front wall. Your neighbors will still hate you.

 

[sigbergaudio]

Does the side/back cancelling nature of cardioid designs actually reduce what can be heard by neighbors to a significant degree? Has anyone tested if cardioid designs are significantly less audible in the non listening room vs. Non cardioid designs?

I appreciate any reply!

I doubt there will be a significant difference.

 

[Flaesh]

in theory

Let's say the front subwoofers emit one watt of acoustic power, and after 26 milliseconds, the rear subwoofers emit 0.7 watts of inverted acoustic power. What will the neighbors hear?)..

 

[Keith_W]

Let's say the front subwoofers emit one watt of acoustic power, and after 26 milliseconds, the rear subwoofers emit 0.7 watts of inverted acoustic power. What will the neighbors hear?)..

If the subs are set up as a DBA they should hear 0.3W, if anything at all?

Anyway I am open to being corrected. If our friend Sigberg (who sells cardioids) and Absolute (who has done the test) says that there is no difference, I think they are probably correct and I am wrong.

 

[Flaesh]

I don't know. The police once came to the sounds of Dupré's "Ruins"; they said they were following the music, but it's possible (though unlikely) that the neighbors called the police.
Let's not complicate things with a delay and gain. Here's John Kreskovsky's article about dipole bass without dipole woofers https://musicanddesign.speakerdesign.net/DP_woofer_room.html I'll reread it tomorrow..

Another good thread by @NTK https://www.audiosciencereview.com/...ectivity-patterns-couple-to-room-modes.45518/

 

[Duke]

Here's John Kreskovsky's article about dipole bass without dipole woofers https://musicanddesign.speakerdesign.net/DP_woofer_room.html I'll reread it tomorrow.

Years ago I tried several variations on John Kreskovsky's configuration (two subwoofers like he shows; four subwoofers with both inverted subs in the rear; and four subwoofers with the inverted subs on a diagonal). After equalization my subjective impression was that the pitch definition was good but "impact" was poor.

 

[NTK]

I don't know. The police once came to the sounds of Dupré's "Ruins"; they said they were following the music, but it's possible (though unlikely) that the neighbors called the police.
Let's not complicate things with a delay and gain. Here's John Kreskovsky's article about dipole bass without dipole woofers https://musicanddesign.speakerdesign.net/DP_woofer_room.html I'll reread it tomorrow..

Another good thread by @NTK https://www.audiosciencereview.com/...ectivity-patterns-couple-to-room-modes.45518/

Do you remember this thread, which you also had contributed? Edechamps and I did some in-room response simulations using FEA. I can try running a few cases and see what comes out.

Bass arriving out of phase at the listening position

So riddle me this: The above graph shows the response at my listening position from my left speaker (red), right speaker (green) as well as the response of both playing at the same time (blue). All graphs use 1/12 octave smoothing for readability. Ignore the large null on the right channel...

www.audiosciencereview.com

 

[Goldhamster916]

No. One could argue theoretically, but in reality it's the bass that's most annoying for neighbors and there's no cardioide effect at those frequencies. Not that it would matter anyways as directivity in the sub 100 hz region is irrelevant in small rooms. Our lack of impulse sensitivity in the bass means the sound would have bounced around the room a few times before we could pick up on it, rendering any directivity meaningless. We hear the steady-state modal characteristics of the room/speaker interaction, not the impulse at low frequencies.

I have tested this with Kii Three. Made no difference in the bedroom behind the front wall. Your neighbors will still hate you.

Thanks for taking the time to answer

 

[sigbergaudio]

Let's say the front subwoofers emit one watt of acoustic power, and after 26 milliseconds, the rear subwoofers emit 0.7 watts of inverted acoustic power. What will the neighbors hear?)..

I may have misunderstood, but the question wasn't about subwoofers, was it? Beyond, that, I suspect even an active cardioid subwoofer setup in an domestic setting may not have much effect with regards to neighbors (which may also live in any direction, not necessarily behind the speakers).

 

[Flaesh]

the question wasn't about subwoofers

True. But then the question of neighbors being able to hear a sound arose, and then the thesis about lower frequencies being more audible to neighbors...
Maybe bass audibility for neighbors deserves a separate branch. Or does such a thread already exist?

 

[Heinrich]

I appreciate any reply!

Maybe bass audibility for neighbors deserves a separate branch. Or does such a thread already exist?

Given a certain sound pressure level at the primary listener's ears, a higher directivity (cardiod) reduces the diffuse field, logically.
A lower diffuse field will reduce the grand total sound leakage through the walls, naturally.
Of course the desired effect depends on which wall separates the secondary listeners from the sound field.

As always it's complicated.

One word of caution: a higher directivity will reduce room interaction, means lesser reflections from boundaries. But is that feasible? Below the Schroeder frequency one wants as much reflections as possible, because the wider distribution of reflections will fill in nulls and cut peaks towards a smoother pattern of so called resonances. (Often forgotten, when discussing directional woofers.)

From a practical perspective, the transfer through the house's construction depends not only on the walls' isolated (isolating) properties. One can have nasty leakage paths, barely predictable, from a single reinforcement bolt somewhere. A single frequency might travel without attentuation down to the basement, and every other are quiet. So, resonances are the worst to have. You see the conflict? Higher directivity probably raises singled out resonances**, while resonances are the main contribution to sound leakage. Also reinforced by the hefty non-linearity of the ear's sensitivity towards lower frequencies.

An anecdote because this is DIY. Speaker enclosures--what many people think is enclosure wall resonance is actually the resonance of the air inside the cavity, that sound traveling through. I proved it practically and theoretically. And some other too. Of course this enlightment was discarded by the community, as they always do.

** not necessarily at the listener's ears but elsewhere, where it still might find a path to the neighbors.

 

[Grimoire]

Surely if some of the sound which the neighbours would normally hear is being cancelled then there is less sound for the neighbours to hear.

 

[sigbergaudio]

Surely if some of the sound which the neighbours would normally hear is being cancelled then there is less sound for the neighbours to hear.

But cardioid speakers aren't inherently less loud, they are more directional.

So if you are listening at 75dB in the listening position, a higher percentage of the sound you are hearing is direct energy (rather than reflected energy), compared to a traditional speaker. But it's still 75dB. So yes, some sound is cancelled out, but the sound going towards the listener is comparably louder, otherwise it wouldn't still be 75dB in the listening position.

So a cardioid bass system at an outdoors concert will have less energy for the neighbours since the bass is directed towards the crowd. In a small living room, I suspect the result is a bit more complicated.

 

[Grimoire]

But cardioid speakers aren't inherently less loud, they are more directional.

So if you are listening at 75dB in the listening position, a higher percentage of the sound you are hearing is direct energy (rather than reflected energy), compared to a traditional speaker. But it's still 75dB. So yes, some sound is cancelled out, but the sound going towards the listener is comparably louder, otherwise it wouldn't still be 75dB in the listening position.

So a cardioid bass system at an outdoors concert will have less energy for the neighbours since the bass is directed towards the crowd. In a small living room, I suspect the result is a bit more complicated.

But the neighbours are not at the listening position and the dB levels away from the listening position will be lower. And that is what the neighbours will, on average, be hearing.

 

[Goldhamster916]

I really appreciate the discussion and read any argument with great interest. Really hard to form a final opinion at this point.

 

[Arindal]

Does the side/back cancelling nature of cardioid designs actually reduce what can be heard by neighbors to a significant degree? Has anyone tested if cardioid designs are significantly less audible in the non listening room vs. Non cardioid designs?

Just from own experiments I would say there is some improvement, i.e. attenuation of structure-borne vibration particularly from the rear walls and ceiling, decrease of boominess you typically hear in neighboring rooms as a result of room modes, with cardioids (and dipoles) being used in those frequency bands which are prone to such problems.

No. One could argue theoretically, but in reality it's the bass that's most annoying for neighbors and there's no cardioide effect at those frequencies.

The second part is not quite accurate. There are fullrange cardioids on the market, going as low as 30Hz, as well as many fullrange dipole concepts, and they achieve exactly what the theory would suggest. Even speakers which are not exactly fullrange cardioids, can make a significant difference if they show a similar behavior between 80 and 150Hz. Cardioid behavior solely in midrange and treble, naturally, would not be able to do that.

Our lack of impulse sensitivity in the bass means the sound would have bounced around the room a few times before we could pick up on it, rendering any directivity meaningless.

My own experience and measurements of decay say otherwise. As group delay distortion reaches or exceeds audibility thresholds in the bass region, our ears are actually sensitive to impulse aspects. Same is true to overly long decay which typically comes with resonators or room modes.

Directivity in the bass bands we do not hear in the sense of distinguishing direct from indirect sound (as it is the case with midrange and lower treble), but differences between tight, impulsive and ´fast´ bass compared to boomy, slow, long-decaying and muddled bass.

I have tested this with Kii Three. Made no difference in the bedroom behind the front wall.

Try GGNTKT M3, MEG RL801k, Ecouton TransAr, Linkwitzlabs 521 or anything similar. Maybe in your house problems are solely below 90Hz where the cardioid of a Kii 3 is not doing much.