Do we know if adding directivity to the bass frequencies adds to the sound quality?

[Trdat]

I do not know much more than the concepts that uniform directivity is one feature of good sound quality, I also understand getting that uniform directivity down as low as possible is also another feature of good sound quality. Its obvious why we do not have commercial designs that have uniform directivity below say 800hz or 700hz likley due to the mostrosity of bass bins.

Have any science based research or even if its experienced based subjective support to the idea if directivity to as low as possible for the mid bass to 300hz or even lower if its possible produce a significantly better sound as opposed to a standard bass cabinet like the M2?

 

[sigbergaudio]

" Its obvious why we do not have commercial designs that have uniform directivity below say 800hz or 700hz likley due to the mostrosity of bass bins." - not exactly sure how you define uniform directivity, but we do have cardioid designs that have controlled directivity down to 100hz.

 

[voodooless]

Usually horn loaded bass systems have much more directivity control. But it will be hard evaluating the horn loading separately from the directivity aspects of these configurations.

 

[voodooless]

PA stuff also has some solutions:

How to correctly position multiple Subwoofers for Cardioid Deployment - Live Sound

Subwoofers’ cardioid deployments are very useful in a myriad of different production events and fixed installation applications. The question is: how to correctly position such a subwoofer array to get the best possible cardioid performance?

blogs.qsc.com

You don’t see it super often, but in cases where the area is a very public place and sound needs to be contained as least somewhat, this is a very good solution.

 

[Trdat]

" Its obvious why we do not have commercial designs that have uniform directivity below say 800hz or 700hz likley due to the mostrosity of bass bins." - not exactly sure how you define uniform directivity, but we do have cardioid designs that have controlled directivity down to 100hz.

Mind my terminology, and yes that's right there are cardoid designs but I am personally a fan of 15inch midwoofers and curious if my next DIY design employs directivity for the midwoofer would it add an audible difference and if so to what hz are we aiming for?

 

[Trdat]

Usually horn loaded bass systems have much more directivity control. But it will be hard evaluating the horn loading separately from the directivity aspects of these configurations.

So are you saying that the horn loading is seperate from the horn loading? Sorry I am confused from the second part of your statement can you clarify...
?

 

[Trdat]

PA stuff also has some solutions:

How to correctly position multiple Subwoofers for Cardioid Deployment - Live Sound

Subwoofers’ cardioid deployments are very useful in a myriad of different production events and fixed installation applications. The question is: how to correctly position such a subwoofer array to get the best possible cardioid performance?

blogs.qsc.com

You don’t see it super often, but in cases where the area is a very public place and sound needs to be contained as least somewhat, this is a very good solution.

Right now, I would like to understand more about the advantages of say the midwoofer range although I am interested in the subwoofer range as well. You mention containing is that the only objective of cardoid bass or would it present other advantages sonically?

 

[sigbergaudio]

Mind my terminology, and yes that's right there are cardoid designs but I am personally a fan of 15inch midwoofers and curious if my next DIY design employs directivity for the midwoofer would it add an audible difference and if so to what hz are we aiming for?

Our Manta only has a 12" so I guess that's out then.

For a cardioid midwoofer, personally I would aim for ~100hz, since the Schroeder transition area will benefit, so you'd be likely to see (hear) improvements in the 100-500hz area, so basically the entire upper bass / lower mid area. And at least if it's a passive design, the cardioidi effect will in practice cover the same range as the driver.

In our upcoming floorstander it will be a bit of a compromise due to it being a 3-way design, so there the cardioid will stop at 150-200hz, but go up to 1500hz.

 

[voodooless]

So are you saying that the horn loading is seperate from the horn loading? Sorry I am confused from the second part of your statement can you clarify...
?

No, I say that it’s hard to separately evaluate the two concepts because they are mixed in one design.

Right now, I would like to understand more about the advantages of say the midwoofer range although I am interested in the subwoofer range as well. You mention containing is that the only objective of cardoid bass or would it present other advantages sonically?

A smaller version would be usable higher up (smaller distance between front and back woofer). Also look at @sigbergaudio’s concept. That can be scaled to larger systems as well, and has in fact been done by one of the ASR members.. can’t find the topic right now though…

 

[Trdat]

Our Manta only has a 12" so I guess that's out then.

Currently, its a learning process for me but I never discount purchasing a well designed speaker. I often keep an eye on the Scandinavian designs and the threads on your specific products. But, generally my understanding wants to progress in the midbass cabinets for a 15 inch.

For a cardioid midwoofer, personally I would aim for ~100hz, since the Schroeder transition area will benefit, so you'd be likely to see (hear) improvements in the 100-500hz area, so basically the entire upper bass / lower mid area. And at least if it's a passive design, the cardioidi effect will in practice cover the same range as the driver.

Thanks, this is what a simple research brings out from forums and not just from sellers but general DIY'ers with the objective of achieving directivity control as low as possible. I was just keen to see what people had to say here.

I our upcoming floorstander it will be a bit of a compromise due to it being a 3-way design, so there the cardioid will stop at 150-200hz, but go up to 1500hz.

I''l take a look.

 

[Trdat]

No, I say that it’s hard to separately evaluate the two concepts because they are mixed in one design.


A smaller version would be usable higher up (smaller distance between front and back woofer). Also look at @sigbergaudio’s concept. That can be scaled to larger systems as well, and has in fact been done by one of the ASR members.. can’t find the topic right now though…

Got it the horn loading vs directivity.

 

[Rick Sykora]

This is pretty much what Directiva r2 is meant to test.

The main question is whether the slots cause a different tradeoff than getting directivity down to hundreds of hertz. The room element weighs in too. A better question may be whether room treatment is more productive than seeking controlled directivity in a speaker's upper bass. Room treatment is certainly more flexible but perhaps not as aesthetically acceptable.

As speakers integrate DSP more and can adapt to the room, suspect this will become the norm. There are a few hifi speakers that allow a glimpse into this future but are pricey for now.

 

[sigbergaudio]

This is pretty much what Directiva r2 is meant to test.

The main question is whether the slots cause a different tradeoff than getting directivity down to hundreds of hertz. The room element weighs in too. A better question may be whether room treatment is more productive than seeking controlled directivity in a speaker's upper bass. Room treatment is certainly more flexible but perhaps not as aesthetically acceptable.

As speakers integrate DSP more and can adapt to the room, suspect this will become the norm. There are a few hifi speakers that allow a glimpse into this future but are pricey for now.

In my experience, cardioid designs sound even better in well treated rooms (as any other speaker). So treatment doesn't replace cardioid or remove the need for it. You will benefit from the effect regardless of the state of the room.

That being said, it's fair to say that the difference between an untreated room and a well treated room is larger than the difference between a non-cardioid and cardioid speaker.

 

[gnarly]

I've built DIY conical horns that hold a 90 degree pattern to about 230Hz, using Keele's classic formula, expressed in chart below.
But they are big...takes a 48" width to do that.
Pattern control with a horn gets crazy big quick going lower; for instance 100Hz would require a horn mouth 9ft wide.

Some horizontal directivity is gained in the subwoofer freq range, when a number of large subs are deployed side by side; or vertically if hung in a vertical line.
It all comes down to wavelengths vs baffle/horn or line size.

With my 230Hz horn, the subjective take is sound gets cleaner and more coherent, for lack of better words. Kinda sounds more like a good full-range electrostat.


I've no experience with cardioid main speakers, but do have some with prosound subs used from 100Hz down, outdoors.
Sound quality takes a small hit whenever cardioid is deployed imo. Not huge, but definitely audible. The stronger the cardioid nulling lobes, the more audible the hit.

My take is multiple sources are multiple sources...and they simply have a sonic price as the number of sources increase..
Which is why horns are so elegant....damn shame about size though, for most folks.

 

[MKR]

In my experience, cardioid designs sound even better in well treated rooms (as any other speaker). So treatment doesn't replace cardioid or remove the need for it. You will benefit from the effect regardless of the state of the room.

That being said, it's fair to say that the difference between an untreated room and a well treated room is larger than the difference between a non-cardioid and cardioid speaker.

I respectfully disagree … A properly designed cardioid should reduce or altogether remove the need for room treatment.

 

[Trdat]

I've built DIY conical horns that hold a 90 degree pattern to about 230Hz, using Keele's classic formula, expressed in chart below.
But they are big...takes a 48" width to do that.
Pattern control with a horn gets crazy big quick going lower; for instance 100Hz would require a horn mouth 9ft wide.

I have a 90 by 40 horn down to 850hz, its superb. There is some source materialthat sounds better on my wide dispersion speakers but generally the horn 15 inch is my prefered unit.

With my 230Hz horn, the subjective take is sound gets cleaner and more coherent, for lack of better words. Kinda sounds more like a good full-range electrostat.

I get its just subjective but I am keen to know the consensus. Currently, I have the 15 inch midwoofer and curious what a large bass bin would bring to the table.

My take is multiple sources are multiple sources...and they simply have a sonic price as the number of sources increase..
Which is why horns are so elegant....damn shame about size though, for most folks.

The plan is combining the one of B&C coxial compression drivers with a 15 inch in a bass bin when I get a larger place.

 

[sigbergaudio]

I respectfully disagree … A properly designed cardioid should reduce or altogether remove the need for room treatment.

Reduce, yes. Altogether remove; Not possible.

 

[Trdat]

I respectfully disagree … A properly designed cardioid should reduce or altogether remove the need for room treatment.

Yeh but there is still interaction between speaker and room regardless if its directed towards the listener. Plus, there are orders of reflections that can be manipulated including that of preffered RT60 decay/decay times. So potentially the cardoid relieves a lot of the hard work but I am curious as why you would say that altogether remove the need for room treatment. That is if of course the person is keen to improve the sound rather than make do with what it has and concentrate on the speaker.

 

[MKR]

Yeh but there is still interaction between speaker and room regardless if its directed towards the listener. Plus, there are orders of reflections that can be manipulated including that of preffered RT60 decay/decay times. So potentially the cardoid relieves a lot of the hard work but I am curious as why you would say that altogether remove the need for room treatment. That is if of course the person is keen to improve the sound rather than make do with what it has and concentrate on the speaker.

Allow me to elaborate/clarify … I am referring to the listener/customer that does not have a dedicated listening room, rather it is a normal listening space, and does not have the need to get that last small percentage of improvement that treatment would provide with a properly designed speaker system (“properly“ also implies built in room EQ by the way). Not all home users want to make their room look like an insane asylum padded cell, nor would they be allowed to even if they wanted by their significant other. A benefit and selling point of the new generation of active systems with cardioid and REQ.

But yes, to achieve perfection, I agree, even with a speaker like D&D, some minor amount of RT may be necessary (emphasis on minor)

 

[Trdat]

Allow me to elaborate/clarify … I am referring to the listener/customer that does not have a dedicated listening room, rather it is a normal listening space, and does not have the need to get that last small percentage of improvement that treatment would provide with a properly designed speaker system (“properly“ also implies built in room EQ by the way). Not all home users want to make their room look like an insane asylum padded cell, nor would they be allowed to even if they wanted by their significant other. A benefit and selling point of the new generation of active systems with cardioid and REQ.

But yes, to achieve perfection, I agree, even with a speaker like D&D, some minor amount of RT may be necessary (emphasis on minor)

This is the Amir perspective of limiting room treatment(or however we want to describe the perspective) and its reasonable if the home user wants to concentrate on the speaker to minimize or like you put it altogether remove treatment. Hence, why I added the clause "concentrate on the speaker" as I prempted that the perpective could be from this angle.