There are a lot of things you can do to counter standing waves. I already mentioned an internal Helholtz absorber. If you don't want to do that, build an acoustical sump. For that you fill the bottom of the speaker ~30cm with high absorbant material, mineral wool i.e., even if I'm usually not a friend of these because of the particles. Put a top layer of fabric or fine acoustical foam above them. Very cheap and effective too, and you can change it quickly if you aren't satisfied.
That'll still give you diffraction/reflection - just at a different angle. Rounding with a great radius is actually the best you can do, followed by a large beveled edge.
You see something and want to implement it on your project without knowing what it does? Just because Troels did it does not mean it's actually good.
Measurements under angles are often only shown if they are good and he just drops posting it if it isn't. He does infact often chose compromises highly criticised by other speaker builders. Troels did a lot of things because he deemed one advantage much higher than the sub-par deficites he creates by that. The stepped baffles improve the time/phase alignment but make the vertical dispersion a lot worse because of the reflection and diffraction at the steps/bevels, making the room impression a lot different, even strange, depending on the material played. I've heard 2 of his speakers, they sounded quite good with 'their' type of music. However, with genres/songs 'not their type' it sounded merely just average despite being a lot more expensive. If you want speakers that are neutral, no matter what's being played, avoid that.
I could ramble on about design and advanages or disadvantages of some of the design choices (acoustically and visually). But it's not me who decides what's more important. I think this is the time you have to decide if design got a higher priority than sound. It's you who has to decide and it's you who has to be satisfied with the result. I won't be offended if you decide against my suggestions, it's only you who decides what goal has to be reached, where the compromises have to be made and where it isn't acceptable. If you change your mind, I try to suggest changes adapting to your goals. Maybe you should try to prioritise which parts of the speaker design are set in stone and got very high priority and which ones you're willing to modify/alter to reach certain goals.
Let me give you an example: Some ppl love fullrange drivers. They know their speakers won't be as linear or disperse the sound as wide or controlled as other speakers or reach the same high spl. But they often decided the amazing room impression, realistic stage location and homogenous sound reproduction is more important for them.
Others are adamant, the tonal accuracy is the most important and yet other ones claim the correct dynamic reproduction is the most important feature of speakers. You can't say any of these ppl are wrong, you can only show them if there are flaws to their way to reach their goal.
I personally prefer authentical, unlimited/compressed dynamic reproduction and room impression over linearity but I also appreciate speakers with perfect linearity. I'm no missionary towards either side (or even other goals), I know how to value each of these qualities and are well aware of the deficites these bring with it too.
My impression of your statements and posts is, you'd like to have a speaker that's neutral and you'd like to achieve a very high fidelity and low-as-possible weak points, making the speakers as universally high end as possible. You didn't express that yourself, that means it's just an assumption and interpreting of your posts by me which may or may not be accurate. My opinion and ..guessing..? your pirorities aren't important, your choices are. It would help a lot to know what your actual design goals are regarding this speaker. It's not me who's projecting 'their' reference over all others (which you encounter a LOT in the forums), it's about reaching what you want to acCompish.
Define what your goals are and you'll get a LOT better help on here.
The set-back is irrelevant if you are using a dsp since you can implement a delay at any time, it's not tied to the physical location anymore. That means, baffle step, reflections, diffractions are so much more important since you can't 'fix' that with the dsp. Or in other words: With a dsp your time/phase alingnment and inearity is a much lower priority, dispersion, reflection and impulse response and decay are much higher priority. (at least if I'm interpreting your posts/goals correctly)
I understand. Your assumptions are really on point. I want to do the best at everything. And yes I know in the back of my head that this is impossible, but I'm trying anyway though. I know the time alignment isn't relevant anymore because of the DSP. I've also said this before multiple times in this thread but I'll repeat it again for the people other than you in this thread who seem to still not have got the message. The separate boxes are not for time alignment, the tweeter won't be set back, it's purely for vibration decoupling and flexibility in the future.
If I have to line up my priorities. I really value a good, deep, realistic soundstage. My speakers already achieve this very well with the current cabinets and I really enjoy it. I also find a deep, extended and when desired very powerfull bass, yet of course also good in terms of quality (tightness, speed, punch and detail). I'm definitely not what's called a bass-head but I really do want powerful bass that can really reach down to the lowest notes. Though this goal has already been achieved with these drivers. They already do what I want in the current enclosures. The enclosures of this design should only make everything better because of the larger volume for the resulting qtc of 0,707 and it's qualities, it's extra structural rigidity and standing-wave-preventing shape.
For the mids, well I already kind of answered that one, I really value a big, realistic soundstage and to my experience the housing of the midrange has a big asset in this area, though obviously the midrange is only part of the entire spectrum. In terms of tonal qualities. I really enjoy good strings, I find myself really enjoying listening to those, like in The Gipsy Kings - Bem Bem Maria, Eric Clapton - Unplugged, Nils Lofgren - Acoustic Live and of course many more. Vocals I also find important. I really want them to sound full and have body, though many day this is result of the frequency response, I disagree totally. I believe to achieve great body and weight in the midrange you need big midranges, which is why I would never want to use smaller than 6,5". To me, 6,5" is the perfect size midrange. I know for a fact you simply can't get the body and weight you get from a 6,5" from a smaller midrange. Though many say this has to do with frequency response, it's untrue. 6,5" mid simply offer superior weight and body. So here I'm on the right path with the Satori MR16P-4. It's very good for vocals, vocals and body are already great with the current enclosures.
Transient response is also really important to my, definitely a big priority. I really value the speed and resulting impact in the mids, as I discovered when listening to the Vivid Audio Kaya 55(?) And Kroma Audio Mimì. Here I'm already well on the right path since the Satori MR16P-4 (and all other Satori drivers overall) are extremely quick. Though the cabinet design also has to do with this.
Dynamics, well I definitely know what they are and how they contribute to the sound since I've heard some extremely dynamically capable systems at Chattelin with Kroma Audio and Vivid Audio speakers. And I can definitely differentiate bad and good dynamics. Actually today I had a big moment where I noticed dynamic differences. I was listening to Spandau Ballet and all remastered songs have much better dynamics and so sound much better. When first listening to the original recordings I also actually noticed how the dynamics in their music were really compressed, which is what led me to looking further into the remastered. So yes I find dynamics very important now I've really heard their contribution, but I don't think it's worth calling them one of my top priorities. However, I don't really have to worry about them. The my Satori MR16P-4 midranges already are very good efficiency and extremely dynamically capable. Apart from their overall amazing performance. Dynamics actually are one of the key qualities the Satori's are known for. So as far as dynamics go, I think they can also be labelled as achieved. I mean, there's nothing I can really do to them anymore anyway. Because dynamics are mainly determined by the drivers and amplifiers, which I already have and aren't subject to change. The only thing changing to the system here is the cabinet. But then again, dynamics are already very good. Something I could eventually do in the future to improve dynamics, would I desire so, is add a power conditioner to the system. Though this has nothing to do with the speakers. Moving on.
For the highs, I want detail, speed and transparency. I really find this very important. It's why I really like the Vivid Audio and Bowers & Wilkins speakers. I just want to hear the tiniest sparkles in the music presented to my with detail and resolution like it's something you'd expect to hear on pretty much any system. Again, here I'm already on the right path with the TW29B-B beryllium dome tweeter. The TW29B-B has some more distortion than the TW29BN-B though better decay characteristics which is what determines clarity and transparency I believe. Though of course here the shape of the baffle is key to good dispersion and minimal coloration.
So, as you can see, my driver selection is already spot-on for my desires. No matter what your desires really. Bass is already achieved. It already was, and with the now bigger, stiffer and acoustically optimisal shaped enclosure it will only get better than it already was. Exterior design doesn't really have an effect on the bass performance.
What I think really has to be focussed on now is getting the design of the baffle and/or overall design of the midrange and tweeter box right.
If I have to line up my priorities. I really value a good, deep, realistic soundstage. My speakers already achieve this very well with the current cabinets and I really enjoy it. I also find a deep, extended and when desired very powerfull bass, yet of course also good in terms of quality (tightness, speed, punch and detail). I'm definitely not what's called a bass-head but I really do want powerful bass that can really reach down to the lowest notes. Though this goal has already been achieved with these drivers. They already do what I want in the current enclosures. The enclosures of this design should only make everything better because of the larger volume for the resulting qtc of 0,707 and it's qualities, it's extra structural rigidity and standing-wave-preventing shape.
For the mids, well I already kind of answered that one, I really value a big, realistic soundstage and to my experience the housing of the midrange has a big asset in this area, though obviously the midrange is only part of the entire spectrum. In terms of tonal qualities. I really enjoy good strings, I find myself really enjoying listening to those, like in The Gipsy Kings - Bem Bem Maria, Eric Clapton - Unplugged, Nils Lofgren - Acoustic Live and of course many more. Vocals I also find important. I really want them to sound full and have body, though many day this is result of the frequency response, I disagree totally. I believe to achieve great body and weight in the midrange you need big midranges, which is why I would never want to use smaller than 6,5". To me, 6,5" is the perfect size midrange. I know for a fact you simply can't get the body and weight you get from a 6,5" from a smaller midrange. Though many say this has to do with frequency response, it's untrue. 6,5" mid simply offer superior weight and body. So here I'm on the right path with the Satori MR16P-4. It's very good for vocals, vocals and body are already great with the current enclosures.
Transient response is also really important to my, definitely a big priority. I really value the speed and resulting impact in the mids, as I discovered when listening to the Vivid Audio Kaya 55(?) And Kroma Audio Mimì. Here I'm already well on the right path since the Satori MR16P-4 (and all other Satori drivers overall) are extremely quick. Though the cabinet design also has to do with this.
Dynamics, well I definitely know what they are and how they contribute to the sound since I've heard some extremely dynamically capable systems at Chattelin with Kroma Audio and Vivid Audio speakers. And I can definitely differentiate bad and good dynamics. Actually today I had a big moment where I noticed dynamic differences. I was listening to Spandau Ballet and all remastered songs have much better dynamics and so sound much better. When first listening to the original recordings I also actually noticed how the dynamics in their music were really compressed, which is what led me to looking further into the remastered. So yes I find dynamics very important now I've really heard their contribution, but I don't think it's worth calling them one of my top priorities. However, I don't really have to worry about them. The my Satori MR16P-4 midranges already are very good efficiency and extremely dynamically capable. Apart from their overall amazing performance. Dynamics actually are one of the key qualities the Satori's are known for. So as far as dynamics go, I think they can also be labelled as achieved. I mean, there's nothing I can really do to them anymore anyway. Because dynamics are mainly determined by the drivers and amplifiers, which I already have and aren't subject to change. The only thing changing to the system here is the cabinet. But then again, dynamics are already very good. Something I could eventually do in the future to improve dynamics, would I desire so, is add a power conditioner to the system. Though this has nothing to do with the speakers. Moving on.
For the highs, I want detail, speed and transparency. I really find this very important. It's why I really like the Vivid Audio and Bowers & Wilkins speakers. I just want to hear the tiniest sparkles in the music presented to my with detail and resolution like it's something you'd expect to hear on pretty much any system. Again, here I'm already on the right path with the TW29B-B beryllium dome tweeter. The TW29B-B has some more distortion than the TW29BN-B though better decay characteristics which is what determines clarity and transparency I believe. Though of course here the shape of the baffle is key to good dispersion and minimal coloration.
So, as you can see, my driver selection is already spot-on for my desires. No matter what your desires really. Bass is already achieved. It already was, and with the now bigger, stiffer and acoustically optimisal shaped enclosure it will only get better than it already was. Exterior design doesn't really have an effect on the bass performance.
What I think really has to be focussed on now is getting the design of the baffle and/or overall design of the midrange and tweeter box right.
This is one way to achieve smoothness and continuity through this lower midrange band. Otherwise, overcoming baffle step/room modes, and a crossover is very challenging to achieve the same result in other ways.
Okay so about the vertical standing waves in the bass enclosure. They can be prevented by a big stash of dense damping material in the bottom of the cabinet. If I where to put that in the bottom of my cabinets, are the slanted top and bottom still necessary/do they still make a significant difference? Or won't it make pretty much any difference if they weren't there?
Of course they will always have an effect but is it still that significant at all if the standing waves are already being dealt with by the damping material?
I'm asking because I want to make the best of this but removing the slanted top and bottom will make the construction a whole lot simpler. If they will still make a significant difference I'll keep them in but I would like to remove them if that's not the case.
Of course they will always have an effect but is it still that significant at all if the standing waves are already being dealt with by the damping material?
I'm asking because I want to make the best of this but removing the slanted top and bottom will make the construction a whole lot simpler. If they will still make a significant difference I'll keep them in but I would like to remove them if that's not the case.
Let's say I'll fill it with thick stuff to as high as the bottom woofer. This will damp very heavily. What difference will this large amount of dampening make to the sound? Qtc will lower and standing waves will be reduced but what will it do to the resulting sound? When I had a too big stash of left-over dampening material in my room the bass wasn't really perceivable and really not their. In case of the midrange chamber it really compressed dynamics but mainly made the sound overly bright, lose its weight and ruin the soundstage and imaging.
Will there be any of these negative effects in the bass enclosure if there is a lot of heavy damping? Or is this not the case with bass enclosures?
Will there be any of these negative effects in the bass enclosure if there is a lot of heavy damping? Or is this not the case with bass enclosures?
All walls will be covered with normal poly fill, the stuff you find in pillows. But I'm talking about the very dense stuff.
But how about the specifications of the enclosure then?
In unibox with damping on "walls covered" the qtc is at 0,707 in a volume of 72 L with a F3 of 44,9 Hz. But this changes with the damping. With the damping at "heavy fill" qtc is at 0,707 in a volume of just 49 L with a F3 of 49,4 Hz. keeping the volume at 72 L gives a qtc of 0,632 with a F3 of 47,5 Hz but more graduate roll off and the woofers reach Xmax quicker.
But how about the specifications of the enclosure then?
In unibox with damping on "walls covered" the qtc is at 0,707 in a volume of 72 L with a F3 of 44,9 Hz. But this changes with the damping. With the damping at "heavy fill" qtc is at 0,707 in a volume of just 49 L with a F3 of 49,4 Hz. keeping the volume at 72 L gives a qtc of 0,632 with a F3 of 47,5 Hz but more graduate roll off and the woofers reach Xmax quicker.
For your mid cabinet I would make the bottom and top more narrow, so there's more diffusion.
A bit like XTZ did in their Divine.
As stuffing for the mid: Twaron angelhair 3gr/liter, works phenomenal !
A bit like XTZ did in their Divine.
As stuffing for the mid: Twaron angelhair 3gr/liter, works phenomenal !
Polyfill will not be very effective on the walls. It should fill the enclosure. As well as the volume you fill there is the density you fill it at. Well teased polyfill can compress to pretty dense. We would also line the walls near the drivers with 12mm cotton or wool felt. I second the suggestion of quality “polyfill”. Acoutastuff is readily available over here so is what we use.
Note that to humans F3 is meaningless (Toole). What is F6/F10?
I like to target Q = 0.58 with sealed boxes i do. It better accounts for typical room gain.
dave
Okay, well I was just thinking of fiberglass wool you'd normally put in the walls to keep your house warm since it's very effective and cheap. It does spread quite some nasty particles though but this shouldn't be a problem because it's a sealed enclosure. Will this be effective or does it have to be combined with other kind of material as well? The sheep wool is quite expensive.
There seem to be a lot of different kinds of material and everybody says different things about their qualities.
What are the different options for damping material and which are most effective and for what use?
There seem to be a lot of different kinds of material and everybody says different things about their qualities.
What are the different options for damping material and which are most effective and for what use?
So I removed the slanted top and bottom and did some other tweaks to the enclosure again to make the design and eventual construction a lot simpler and make the enclosure stronger in the end.
I made the baffles slightly wider to 24,5 cm so the entire woofer, including the mounting lips fit in the width of the baffle. This way the recessed edge around the mounting hole were the mounting lips of the woofer fall into can be done directly by CNC instead of having to do it by hand with a mill after everything has been put together. This makes it a lot simpler, I no more need advanced tools and perhaps the help of a woodworker which saves a lot of time and fuss.
Making the baffle slightly wider made the entire enclosure to become slightly wider. The width of the back of the enclosure on which the amplifiers will be mounted will would always be 13 cm. Because the difference in width between the widest point of the enclosure, in the middle, and the width of the back plate is now bigger, the diameter of the rounding has increased slightly, again slightly improving internal acoustics. The extra width also made for some more volume but because a bigger volume isn't necessary and there are limits to how big the volume should get (though it's nowhere near to getting too big yet) this left some space for some more wood. So, I increased the thickness of the side walls to 3,5 cm/1-1/3", again making the cabinet stronger, stiffer and heavier.
Also, this is kind of a coincidence with the dimensions, but one of the big braces now doubles as the top plate for the amplifier chamber. This again makes it simpler, saves two pieces of wood, and eventually makes the amplifier chamber in and the construction around it stronger and reduces the risk of leaks.
There now are horizontal braces every four layers/10 cm. And there is a vertical brace amongst the entire height of the cabinet with the edges around the holes in them against the horizontal braces, again reinforcing them. This skeleton in combination with the 5 cm thick baffle and 3,5 cm thick side walls will make for a extremely stiff cabinet.
I made the baffles slightly wider to 24,5 cm so the entire woofer, including the mounting lips fit in the width of the baffle. This way the recessed edge around the mounting hole were the mounting lips of the woofer fall into can be done directly by CNC instead of having to do it by hand with a mill after everything has been put together. This makes it a lot simpler, I no more need advanced tools and perhaps the help of a woodworker which saves a lot of time and fuss.
Making the baffle slightly wider made the entire enclosure to become slightly wider. The width of the back of the enclosure on which the amplifiers will be mounted will would always be 13 cm. Because the difference in width between the widest point of the enclosure, in the middle, and the width of the back plate is now bigger, the diameter of the rounding has increased slightly, again slightly improving internal acoustics. The extra width also made for some more volume but because a bigger volume isn't necessary and there are limits to how big the volume should get (though it's nowhere near to getting too big yet) this left some space for some more wood. So, I increased the thickness of the side walls to 3,5 cm/1-1/3", again making the cabinet stronger, stiffer and heavier.
Also, this is kind of a coincidence with the dimensions, but one of the big braces now doubles as the top plate for the amplifier chamber. This again makes it simpler, saves two pieces of wood, and eventually makes the amplifier chamber in and the construction around it stronger and reduces the risk of leaks.
There now are horizontal braces every four layers/10 cm. And there is a vertical brace amongst the entire height of the cabinet with the edges around the holes in them against the horizontal braces, again reinforcing them. This skeleton in combination with the 5 cm thick baffle and 3,5 cm thick side walls will make for a extremely stiff cabinet.
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Just as you found with your diffusers, sound has a size and that's important when damping.
Is much more effective than polyfill.
Is much more effective than polyfill.
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