devstation18
Member
Thanks
Open Baffle Speakers Advise Please
- Thread starter msagar
- Start date
If only you are going to listen music in your room then Equalize for your sweet spot. If there are others too in the room then bass needs to be optimized for all listening position.Okay a very honest question from me. This is make or break for me.
Having spent quite a bit of time on the DIY threads on the net. I quickly realize that using these design tools to get a scentifically correct measuring speaker is beyond my skill level. And apart from some basic simulation as to acheiveable frequency range, I dont think i can get to the dispersion characteristics etc.
Now I understand that the goal of designing a sceintifically good speaker is to perform optimally in all rooms. But since anything I build will be solely used in my room, will it suffice if I place the frankenstein in the room, at my usual speaker position, and then get the frequency and time coherence correct at my listening position. I guess this will anyways sum up the speaker output, room interaction, dispersion everything. And I only need to get this right at one position in one room. Which is my listening position in my room. Am I correct in assuming this
If that is doable with active dsp, then I can give it a fair shot. Otherwise, I might better utilise my time designing a rocket to reach the sun
Yelamanchili manohar
Well-Known Member
Thanks @yogibear and @Hari Iyer 
Was just about losing hope. And is all the reassurance i need
Iam sure i will come back and report that they sound great. We are all love our children despite their follies right
Was just about losing hope. And is all the reassurance i need
Iam sure i will come back and report that they sound great. We are all love our children despite their follies right
Vineethkumar01
Well-Known Member
@Yelamanchili manohar: There is nothing wrong with doing a build and testing it to see if it turns out to according to your expectations. In fact, I encourage it. Only when we experiment, build, and hear speaker for ourself in our kind of room will we learn more about speakers and our own preferences.
All I was saying is to be aware of what has been done in the area in general. As you are aware by now, there is comprehensive literature on the subject of open baffle speaker design. There are old and new versions of tools that help optimise a build with technical complexities ranging from tools that do back-of-the-envelope calculations, tools that do more advanced geometry-based calculations to tools that do an all out wavefront modelling level approach. It is up to one to learn/choose and apply any of these in his/her own personal build. Then there are analysis like cntrl's from which we can learn and avoid the pitfalls that others might have willingly or unwillingly chosen, for whatever reason.
In general, when done well, open baffle/dipole speaker designs can give full bandwidth constant directivity. Now why is that important? It is important because the direct and reflected sounds will have a similar spectral balance. Speakers that do this can often sound very pleasant to the ears (conditioned on many other factors including transducer/driver selection) not only for the person sitting in a sweet spot but also for others around and all this in a normal-ish room that has not been treated to death. This is all possible because a well-designed open baffle speaker has a figure-8/dipole radiation pattern, significantly attenuating the energy hitting the sidewalls. It is generally thought that very early reflections (the ones that occur due to the baffle design/diffraction) to a certain amount of early reflections will clutter the imaging. By getting rid of the side wall reflections with the dipole, at least to some extent, we are permitting more of direct sound to reach us.
Next aspect is the energy that goes from the back of the baffle/speaker into the room. They may reach the ear as late to very late reflections (depending upon the placement of the speaker in the room) and contribute to that very wide soundstage, a character, that open baffle speakers are often famous for (another reason why open baffle speakers should be pulled out into the middle of the room
). Then comes the bass. Dipole bass interacts differently with the room than monopole and cardioid bass. More interested? Take a look here:
www.audiosciencereview.com
Now what happens if the radiation pattern widens over a narrow frequency range like what we saw in cntrl's thread. It is going to impact the energy balance across the spectrum. Some frequencies in the sound will gain more prominence in the overall soundstage. If this is not taken care in the design itself, one has to go putting all kinds of band-aid tweaks to ensure that energy spectral distribution at the listening position is balanced or to one's taste. This includes putting up absorber panels in areas one may not want to in a room.
Anyway, all the good characters of open baffle speakers help with certain genres of music like what Linkwitz like, Classical, Orchestral, and maybe others too. Some people have been disappointed with such speakers for EDM and other genres. Again up to oneself to listen and decide.
Regarding building and measurements. I would ensure that I have a DSP in hand from the start since open baffle speakers are inefficient radiators in the bass range and are going to require significant enough equalization in the bass. I would choose drivers with good enough specs that can handle EQ across the spectrum. I would personally go with a low diffraction baffle and choose crossover points based on modelling and measurements made with a prototype/final speaker. I would go for an all out radiation pattern measurement to verify that my engineering details are as expected. This means taking nearfield measurements for driver passband EQ, far-field measurements for radiation pattern measurement, and listening position measurements for tweaking the spectral balance to my taste. But that is just my approach. One can even tune based on listening if one knows what ones expectation of sound is and tuning which way in that DSP will help get there. Unfortunately, I am not that guy
Just keep in mind that it is spectral balance of energy sent out into the room (this is what is shown by the radiation pattern to some extent) that matters w.r.t the sound that hear and attribute as the speaker's sound character and not the single-axis measurement. If not ready to go for all-out measurements, keep in mind good design choices that can help us ensure that, atleast to some extent and then decide things based whatever limited measurements you can do. More than all that, have fun with the build and learning
All I was saying is to be aware of what has been done in the area in general. As you are aware by now, there is comprehensive literature on the subject of open baffle speaker design. There are old and new versions of tools that help optimise a build with technical complexities ranging from tools that do back-of-the-envelope calculations, tools that do more advanced geometry-based calculations to tools that do an all out wavefront modelling level approach. It is up to one to learn/choose and apply any of these in his/her own personal build. Then there are analysis like cntrl's from which we can learn and avoid the pitfalls that others might have willingly or unwillingly chosen, for whatever reason.
In general, when done well, open baffle/dipole speaker designs can give full bandwidth constant directivity. Now why is that important? It is important because the direct and reflected sounds will have a similar spectral balance. Speakers that do this can often sound very pleasant to the ears (conditioned on many other factors including transducer/driver selection) not only for the person sitting in a sweet spot but also for others around and all this in a normal-ish room that has not been treated to death. This is all possible because a well-designed open baffle speaker has a figure-8/dipole radiation pattern, significantly attenuating the energy hitting the sidewalls. It is generally thought that very early reflections (the ones that occur due to the baffle design/diffraction) to a certain amount of early reflections will clutter the imaging. By getting rid of the side wall reflections with the dipole, at least to some extent, we are permitting more of direct sound to reach us.
Next aspect is the energy that goes from the back of the baffle/speaker into the room. They may reach the ear as late to very late reflections (depending upon the placement of the speaker in the room) and contribute to that very wide soundstage, a character, that open baffle speakers are often famous for (another reason why open baffle speakers should be pulled out into the middle of the room
). Then comes the bass. Dipole bass interacts differently with the room than monopole and cardioid bass. More interested? Take a look here:
Visualizing How Different Loudspeaker LF Directivity Patterns Couple to Room Modes
This opening post is to demonstrate how different loudspeaker low frequency directvity patterns couple to our room modes. If you are unfamiliar with what room modes are, please refer to @DonH56's excellent thread for an in-depth introduction...
www.audiosciencereview.com
Now what happens if the radiation pattern widens over a narrow frequency range like what we saw in cntrl's thread. It is going to impact the energy balance across the spectrum. Some frequencies in the sound will gain more prominence in the overall soundstage. If this is not taken care in the design itself, one has to go putting all kinds of band-aid tweaks to ensure that energy spectral distribution at the listening position is balanced or to one's taste. This includes putting up absorber panels in areas one may not want to in a room.
Anyway, all the good characters of open baffle speakers help with certain genres of music like what Linkwitz like, Classical, Orchestral, and maybe others too. Some people have been disappointed with such speakers for EDM and other genres. Again up to oneself to listen and decide.
Regarding building and measurements. I would ensure that I have a DSP in hand from the start since open baffle speakers are inefficient radiators in the bass range and are going to require significant enough equalization in the bass. I would choose drivers with good enough specs that can handle EQ across the spectrum. I would personally go with a low diffraction baffle and choose crossover points based on modelling and measurements made with a prototype/final speaker. I would go for an all out radiation pattern measurement to verify that my engineering details are as expected. This means taking nearfield measurements for driver passband EQ, far-field measurements for radiation pattern measurement, and listening position measurements for tweaking the spectral balance to my taste. But that is just my approach. One can even tune based on listening if one knows what ones expectation of sound is and tuning which way in that DSP will help get there. Unfortunately, I am not that guy
Just keep in mind that it is spectral balance of energy sent out into the room (this is what is shown by the radiation pattern to some extent) that matters w.r.t the sound that hear and attribute as the speaker's sound character and not the single-axis measurement. If not ready to go for all-out measurements, keep in mind good design choices that can help us ensure that, atleast to some extent and then decide things based whatever limited measurements you can do. More than all that, have fun with the build and learning
Yelamanchili manohar
Well-Known Member
Thanks a ton for taking the time to pen the above@Yelamanchili manohar: There is nothing wrong with doing a build and testing it to see if it turns out to according to your expectations. In fact, I encourage it. Only when we experiment, build, and hear speaker for ourself in our kind of room will we learn more about speakers and our own preferences.
All I was saying is to be aware of what has been done in the area in general. As you are aware by now, there is comprehensive literature on the subject of open baffle speaker design. There are old and new versions of tools that help optimise a build with technical complexities ranging from tools that do back-of-the-envelope calculations, tools that do more advanced geometry-based calculations to tools that do an all out wavefront modelling level approach. It is up to one to learn/choose and apply any of these in his/her own personal build. Then there are analysis like cntrl's from which we can learn and avoid the pitfalls that others might have willingly or unwillingly chosen, for whatever reason.
In general, when done well, open baffle/dipole speaker designs can give full bandwidth constant directivity. Now why is that important? It is important because the direct and reflected sounds will have a similar spectral balance. Speakers that do this can often sound very pleasant to the ears (conditioned on many other factors including transducer/driver selection) not only for the person sitting in a sweet spot but also for others around and all this in a normal-ish room that has not been treated to death. This is all possible because a well-designed open baffle speaker has a figure-8/dipole radiation pattern, significantly attenuating the energy hitting the sidewalls. It is generally thought that very early reflections (the ones that occur due to the baffle design/diffraction) to a certain amount of early reflections will clutter the imaging. By getting rid of the side wall reflections with the dipole, at least to some extent, we are permitting more of direct sound to reach us.
Next aspect is the energy that goes from the back of the baffle/speaker into the room. They may reach the ear as late to very late reflections (depending upon the placement of the speaker in the room) and contribute to that very wide soundstage, a character, that open baffle speakers are often famous for (another reason why open baffle speakers should be pulled out into the middle of the room
Visualizing How Different Loudspeaker LF Directivity Patterns Couple to Room Modes
This opening post is to demonstrate how different loudspeaker low frequency directvity patterns couple to our room modes. If you are unfamiliar with what room modes are, please refer to @DonH56's excellent thread for an in-depth introduction...
Now what happens if the radiation pattern widens over a narrow frequency range like what we saw in cntrl's thread. It is going to impact the energy balance across the spectrum. Some frequencies in the sound will gain more prominence in the overall soundstage. If this is not taken care in the design itself, one has to go putting all kinds of band-aid tweaks to ensure that energy spectral distribution at the listening position is balanced or to one's taste. This includes putting up absorber panels in areas one may not want to in a room.
Anyway, all the good characters of open baffle speakers help with certain genres of music like what Linkwitz like, Classical, Orchestral, and maybe others too. Some people have been disappointed with such speakers for EDM and other genres. Again up to oneself to listen and decide.
Regarding building and measurements. I would ensure that I have a DSP in hand from the start since open baffle speakers are inefficient radiators in the bass range and are going to require significant enough equalization in the bass. I would choose drivers with good enough specs that can handle EQ across the spectrum. I would personally go with a low diffraction baffle and choose crossover points based on modelling and measurements made with a prototype/final speaker. I would go for an all out radiation pattern measurement to verify that my engineering details are as expected. This means taking nearfield measurements for driver passband EQ, far-field measurements for radiation pattern measurement, and listening position measurements for tweaking the spectral balance to my taste. But that is just my approach. One can even tune based on listening if one knows what ones expectation of sound is and tuning which way in that DSP will help get there. Unfortunately, I am not that guy
Just keep in mind that it is spectral balance of energy sent out into the room (this is what is shown by the radiation pattern to some extent) that matters w.r.t the sound that hear and attribute as the speaker's sound character and not the single-axis measurement. If not ready to go for all-out measurements, keep in mind good design choices that can help us ensure that, atleast to some extent and then decide things based whatever limited measurements you can do. More than all that, have fun with the build and learning
Will surely think over all thats been said. I definitely need to understand this VitiusCad better. Will start from there in my free time. Thanks again
devstation18
Member
Seems DIY audiocart is interested in HIVi drivers only most of the other brands are out of stock
These were on my shortlist before I decided to build a horn. He has other OB designs on his website as well.
Yelamanchili manohar
Well-Known Member
Thanks a ton for sharing
Was a lovely read. Have to figure out where to source the mid from. Lii song also make a well regarded full range 15 incher that might be easier to source eventually.
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