Hello good sirs,
I come to you for wisdom and advice in regards to understanding what is the tightest bass I can possibly achieve in a folded horn bass cabinet.
The main objective would be a low or even very low volume, but extremely tight ("kicky") bass that hopefully, if possible REMAINS "kicky" all the way down to 20Hz although I am definitely willing to trade some depth for additional speed and authority which is the main purpose as long as it goes pretty damn low, not necessarily all the way down. But I would like to achieve an extremely authoritative bass, I'm not sure what the possible trade offs are, so I'm not sure what I'm willing to sacrifice more - authority down low or overall speed over the entire low frequency range. I will be using digital crossover from the 20Hz to 120 at the lowest, but likely 200 maybe even as high as 400 if the cabinet happens to extend effortlessly that high. From which point I intend to take over with my tower speakers which do have pretty nice upper bass, so I will likely determine the exact crossover through experimentation.
1. What size drivers would I be best served by for the purpose? 10"-15" or something closer to 15"-18" or even larger? Somehow my experience so far makes me distrust large drivers in that they can be sluggish, but of course they do couple more strongly at the very low end and I'm not yet sure which exact frequency is most important to me, but hopefully I can get just big enough to handle the sub bass frequencies gracefully while still being extremely fast, 'get up and go' and responsive at the 80-120Hz too. Maybe it's all about the cabinet and I shouldn't focus so much on the driver diameter, please enlighten me.
2. What requirements for the cabinet should I pay most attention to? length of the horn?, less sharp corners, smoother path? Bracing and rigidity? Bigger mouth? longer throat? Sealed volume where the woofer negative wave is contained? Something else, like flare curve maybe?
3. For amplification I want to use either low powered class A single ended BJT based DIY amp with 10 to around 50 watts (which believe it or not can sound extremely immediate and alive and kicky) or some of the Crown class D amps with pretty much unlimited power, so here comes the question again if for low volume aliveness I want to use something very efficient with the strongest magnets, square profile wire, possibly low excursion etc or high power handling stuff that I can just power with more or less unlimited class D wattage and achieve the ultimate immediacy that way? Exact driver recommendations at various price points are very welcome. I'm EU based. What should I spend more on - the drivers or the amplification (or the cabinet? although that's mostly a time investment) to get actual results that deliver? Low powered amps I already have to be fair, but good class D don't cost an arm and a leg nowadays either and delivers wonderfully controlled high power to the bass.. may be a bit problematic at low volumes, but absolutely shines at high volume.
If I'm gonna be playing above 120Hz, musicality, fidelity, low distortion becomes important too. With all of those considerations, what have been the most popular designs in recent years that I should look into and learn about? Ease of fabrication is of course a great plus, but only if the sacrifices are relatively small. Are there any other questions that I should be asking instead of the above that I have not realized I should ask? I intend to play outside in an open terrain at which point I will surely be tempted to blast them pretty loud... At least that's the intended purpose - outside, but to be fair they will play 98 percent of the time - indoors in a yet undefined, but likely not huge venue at all. Hence the focus on low volume fidelity, but more than low distortion - ability to couple to air and deliver authoritativeness, 'tightness'... at frequencies 20 to 120 or 20 to 200 as the main focus. Although 100Hz crossover works as well if that's a limiting factor. Very curious about you's guys opinions and expertise.
I come to you for wisdom and advice in regards to understanding what is the tightest bass I can possibly achieve in a folded horn bass cabinet.
The main objective would be a low or even very low volume, but extremely tight ("kicky") bass that hopefully, if possible REMAINS "kicky" all the way down to 20Hz although I am definitely willing to trade some depth for additional speed and authority which is the main purpose as long as it goes pretty damn low, not necessarily all the way down. But I would like to achieve an extremely authoritative bass, I'm not sure what the possible trade offs are, so I'm not sure what I'm willing to sacrifice more - authority down low or overall speed over the entire low frequency range. I will be using digital crossover from the 20Hz to 120 at the lowest, but likely 200 maybe even as high as 400 if the cabinet happens to extend effortlessly that high. From which point I intend to take over with my tower speakers which do have pretty nice upper bass, so I will likely determine the exact crossover through experimentation.
1. What size drivers would I be best served by for the purpose? 10"-15" or something closer to 15"-18" or even larger? Somehow my experience so far makes me distrust large drivers in that they can be sluggish, but of course they do couple more strongly at the very low end and I'm not yet sure which exact frequency is most important to me, but hopefully I can get just big enough to handle the sub bass frequencies gracefully while still being extremely fast, 'get up and go' and responsive at the 80-120Hz too. Maybe it's all about the cabinet and I shouldn't focus so much on the driver diameter, please enlighten me.
2. What requirements for the cabinet should I pay most attention to? length of the horn?, less sharp corners, smoother path? Bracing and rigidity? Bigger mouth? longer throat? Sealed volume where the woofer negative wave is contained? Something else, like flare curve maybe?
3. For amplification I want to use either low powered class A single ended BJT based DIY amp with 10 to around 50 watts (which believe it or not can sound extremely immediate and alive and kicky) or some of the Crown class D amps with pretty much unlimited power, so here comes the question again if for low volume aliveness I want to use something very efficient with the strongest magnets, square profile wire, possibly low excursion etc or high power handling stuff that I can just power with more or less unlimited class D wattage and achieve the ultimate immediacy that way? Exact driver recommendations at various price points are very welcome. I'm EU based. What should I spend more on - the drivers or the amplification (or the cabinet? although that's mostly a time investment) to get actual results that deliver? Low powered amps I already have to be fair, but good class D don't cost an arm and a leg nowadays either and delivers wonderfully controlled high power to the bass.. may be a bit problematic at low volumes, but absolutely shines at high volume.
If I'm gonna be playing above 120Hz, musicality, fidelity, low distortion becomes important too. With all of those considerations, what have been the most popular designs in recent years that I should look into and learn about? Ease of fabrication is of course a great plus, but only if the sacrifices are relatively small. Are there any other questions that I should be asking instead of the above that I have not realized I should ask? I intend to play outside in an open terrain at which point I will surely be tempted to blast them pretty loud... At least that's the intended purpose - outside, but to be fair they will play 98 percent of the time - indoors in a yet undefined, but likely not huge venue at all. Hence the focus on low volume fidelity, but more than low distortion - ability to couple to air and deliver authoritativeness, 'tightness'... at frequencies 20 to 120 or 20 to 200 as the main focus. Although 100Hz crossover works as well if that's a limiting factor. Very curious about you's guys opinions and expertise.
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"At the end of the day, you will not listen to theory. It worked for me best to go see real systems, talk and give bottle of good drink to these who offered a listening session". That was the cheapest experience to get. Ever.
On the technical note, the biggest elephant in the room is the room. Then, for lowest distortion and best parameters you need two bands, so subwoofer and a kickbin, but the sound feels sharper and more structured when thy sistem actually DOES give you some harmonic distortion. A lot of bottom end will always feel heavier and slower, you want to go thinner there. And drivers, that's another can of worms. The larger the cone, the less movement per SPL. So less resonance, and faster sound. But you know that realistically it feels otherwise. Now what. I would look for best compromise. A driver with strongest motor and tight suspension. Something like B&C Speakers 15DS115, or some Eighteensound.
On the technical note, the biggest elephant in the room is the room. Then, for lowest distortion and best parameters you need two bands, so subwoofer and a kickbin, but the sound feels sharper and more structured when thy sistem actually DOES give you some harmonic distortion. A lot of bottom end will always feel heavier and slower, you want to go thinner there. And drivers, that's another can of worms. The larger the cone, the less movement per SPL. So less resonance, and faster sound. But you know that realistically it feels otherwise. Now what. I would look for best compromise. A driver with strongest motor and tight suspension. Something like B&C Speakers 15DS115, or some Eighteensound.
Well, in terms of drivers at least the main two camps I can look for them is:
1. maximum heat dissipation and power handling which will likely mean high excursion too. This option would focus on amazing power and speed of class D high wattage.
2. second camp two would be probably older designs and models or maybe something modern too, but - maximum efficiency, maximum sensitivity, irrelevant power handling, since in the right enclosure they will play much louder than I could ever listen to even outside with minimal watts. I have the right amps for this - extremely good BJT designs. This kind of drivers would focus on the strength and size of the magnets then and employ square profile wire coils, not sure about impedance but probably higher. And then I could use for example two smaller ones in parallel, for double the motor, but the same area as a big driver.
Once I choose one of those camps I think it will be much easier for me to figure out the rest as the rest will follow, according to excursion, and the appropriate driver size for the corresponding camp.
1. maximum heat dissipation and power handling which will likely mean high excursion too. This option would focus on amazing power and speed of class D high wattage.
2. second camp two would be probably older designs and models or maybe something modern too, but - maximum efficiency, maximum sensitivity, irrelevant power handling, since in the right enclosure they will play much louder than I could ever listen to even outside with minimal watts. I have the right amps for this - extremely good BJT designs. This kind of drivers would focus on the strength and size of the magnets then and employ square profile wire coils, not sure about impedance but probably higher. And then I could use for example two smaller ones in parallel, for double the motor, but the same area as a big driver.
Once I choose one of those camps I think it will be much easier for me to figure out the rest as the rest will follow, according to excursion, and the appropriate driver size for the corresponding camp.
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It's very unfortunate, but basically one has to do something first, to know then. The subjective set of values are not transferrable as knowledge. In that sense you are on your own. Few 21" solutions sounded fast to me, some 12"s sounded slow and boomy.
So I've been thinking about relatively small drivers with a whole lot of motor. I remembered these ones by JBL. High sensitivity. And they can even take some abuse, high power rating. They may not work so good horn loaded, I don't know, but in a ported enclosure, they produce pretty tight bass. I'm a bit worried just because they have quite high excursion, which I don't actually need. Other than that I think they'd sound quite excellent. I can get two, try building one box with two instead of 4 (leave space on the array) and order 6 more if needed and works as intended.
https://reconingspeakers.com/products-page/jbl-studio-590-8-woofer-model-580j/
But that's just a small idea, I can use whatever drivers, the other idea, which is the one I want to run by you, is this (see pic), this is just rough sketch, but what if I designed an enclosure something like this and used 3-6 such drivers in a row to create a slim or fat box with snail pattern like this. Add a lot of bracing if it's fat (like 6 drivers). Approximately here, I can do calculations later.
https://reconingspeakers.com/products-page/jbl-studio-590-8-woofer-model-580j/
But that's just a small idea, I can use whatever drivers, the other idea, which is the one I want to run by you, is this (see pic), this is just rough sketch, but what if I designed an enclosure something like this and used 3-6 such drivers in a row to create a slim or fat box with snail pattern like this. Add a lot of bracing if it's fat (like 6 drivers). Approximately here, I can do calculations later.
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Depending on the box size, using drivers in a row and situated in this topology, is quite a bad idea. If we were after tight bass the fastest way, I'd start with larger driver in a closed box.
I like the idea of the back chamber that goes ahead of the speaker.
Indeed I 'd keep only the first segment of the horn. You've already reached the double gain from pi reduction ( the power sphere...) so why go further...?;
Indeed I 'd keep only the first segment of the horn. You've already reached the double gain from pi reduction ( the power sphere...) so why go further...?;
A slob-tunnel-horn, most a 6th order bandpass if you put some vents, a turbo mega-cylindro- vent.
Well, doing some research into drivers, my sentiment is shifting from highly efficient drivers towards less efficient, less sensitive, more modern designs if control and transient response is what I'm after. So, neodymium magnets, large diameter voice coils with relatively few turns, but relatively thicker wire. Probably copper clad aluminum, yeah, probably better than straight aluminum. While there may be more efficient drivers, it seems the kind that I described above coupled with high power class D will be more useful for what I'm after, even if I intend to play at low or very low volume.
Ultimately, I can always try using my low power Class A BJT amps and see if I can generate enough volume for my needs. I'm sure they would play more nicely at low volume, but on the other hand I have very low crossover frequency, so I might be mistaken even about that. They would definitely beat even high quality class D at anything approaching mids, but the focus of this discussion is probably no more than up to 200 Hz.
Tl;dr it seems like high current is going to be my friend regardless of volume if I'm after transients...
Now as for the stiffness of suspension, I seem to be reading that low volume would benefit from less stiffness and higher volume from more stiffness. Do I just go with something in the middle? These things are too expensive to leave up to experimentation or chance 🤌🏻
Anyone with an opinion or experience with these?
https://faitalpro.com/en/products/LF_Loudspeakers/product_details/index.php?id=151040110
https://faitalpro.com/en/products/LF_Loudspeakers/product_details/index.php?id=151040100
Ultimately, I can always try using my low power Class A BJT amps and see if I can generate enough volume for my needs. I'm sure they would play more nicely at low volume, but on the other hand I have very low crossover frequency, so I might be mistaken even about that. They would definitely beat even high quality class D at anything approaching mids, but the focus of this discussion is probably no more than up to 200 Hz.
Tl;dr it seems like high current is going to be my friend regardless of volume if I'm after transients...
Now as for the stiffness of suspension, I seem to be reading that low volume would benefit from less stiffness and higher volume from more stiffness. Do I just go with something in the middle? These things are too expensive to leave up to experimentation or chance 🤌🏻
Anyone with an opinion or experience with these?
https://faitalpro.com/en/products/LF_Loudspeakers/product_details/index.php?id=151040110
https://faitalpro.com/en/products/LF_Loudspeakers/product_details/index.php?id=151040100
Probably you are on the right track, since the Faital FH 500 is meant to be used with a front horn(FH).
The 500W power figure suggests that you're a little off the track with the amplifiers you would put beside.
Only in single ended a low damping factor is achievable?! That's the only reason you would want to raise the bass because of it.
Ok, amplifiers, later...
The 60 Hz resonance frequency of the 10FH500 suggests that the bass will be tight but not profound.
The 500W power figure suggests that you're a little off the track with the amplifiers you would put beside.
Only in single ended a low damping factor is achievable?! That's the only reason you would want to raise the bass because of it.
Ok, amplifiers, later...
The 60 Hz resonance frequency of the 10FH500 suggests that the bass will be tight but not profound.
Here are the real challenges.
Sound wavelengths. One cycle at 20hz is 56ft in length, the speed of sound in air is the same for all frequencies.
Our hearing is sensitive to a misalignment between 2 tones of as little as 6ms, that means everything above about 150hz will tend to sound coherent even though it really isn't, but bass tones sound slower and slower the lower you go. The period of a tone at 20hz is 50ms. This means it's simply not possible to reproduce sub-bass with the same apparent "speed" as higher frequencies. If somebody tells you they have a sound system that is "fast" what they are really saying is it has no low bass response.
Even a 1/4 wavelength horn needs a path length of 14ft for 20hz, that is the minimum size, any way you cut it that is going to be a large box.
Thank you all for your elucidations. Yes, of course I don't expect 20 Hz to kick hehe, but I was exaggerating a bit to get my point across of what I'm aiming for. Yes, lets discuss amps later, but a relatively inexpensive crown amp will drive excellently just about anything and for low volumes I can experiment with whatever else I have currently. But there's more to the story than distortion and damping factor, but that's irrelevant right now. And I don't want to rock the boat too much, so that those who could actually help don't get mad at me haha.
As for the length I will have to be satisfied with nothing longer than 1/4 of 30 or 40Hz probably. Even that sounds pretty damn long. I just want to reasonably experiment as close to what I want as possible, not just build the most perfect thing without any compromises or corners cut at the very first try. 30 to 120 Hz frequencies would be the most important for this project.
As for the length I will have to be satisfied with nothing longer than 1/4 of 30 or 40Hz probably. Even that sounds pretty damn long. I just want to reasonably experiment as close to what I want as possible, not just build the most perfect thing without any compromises or corners cut at the very first try. 30 to 120 Hz frequencies would be the most important for this project.
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30Hz is ugly big, indeed. You can get there if you cut some corners and make it into hybrid, but no free lunch. Less efficiency, risk of chuffing and air compression. Been there, done that. If you want to go compact though, then arguably good BR with oversized driver in small box can give you most SPL density with very good parameters. Undertuned, overdamped. Been there. Actually, still being there because for compact designs it worked really nice for me.
You could use the classic Karlson 15 inch cabinet developed in the summer of 1951 for "kick" then a 1/4 wave tapped pipe down to say 30Hz which would add weight to theatre organ and synth recordings. Also - ask some of the PA guys including BFM and CUBO what they would do. How large is your room?
2--4 good 15" per side in a proper reflex box would not be shabby and since you intend to use some power, run them ~ 6th order with Q=2/6dB boost at tuning with an underdamped 2nd order highpass filter to keep the LF crap from wasting excursion.
2--4 good 15" per side in a proper reflex box would not be shabby and since you intend to use some power, run them ~ 6th order with Q=2/6dB boost at tuning with an underdamped 2nd order highpass filter to keep the LF crap from wasting excursion.
Excursion won't be a problem, because listening volume will be low.
Intended space is an open area outdoors.
I would rather have a huge unmanageable box than a tapped horn I think.
Instead of your solution freddi, I'd rather build a BR box like crashpc suggested and shelve the idea until insane huge boxes and substantial expenditures are neither of consequence. However if it can still be put into something like a Forester... I don't know, maybe I don't need super low frequency for the first pancake, but it's the horny sound that I wanted, so if something more compact can deliver the desired speed and tightness, only a bit higher in frequency, I'd like to experiment with that.
Intended space is an open area outdoors.
I would rather have a huge unmanageable box than a tapped horn I think.
Instead of your solution freddi, I'd rather build a BR box like crashpc suggested and shelve the idea until insane huge boxes and substantial expenditures are neither of consequence. However if it can still be put into something like a Forester... I don't know, maybe I don't need super low frequency for the first pancake, but it's the horny sound that I wanted, so if something more compact can deliver the desired speed and tightness, only a bit higher in frequency, I'd like to experiment with that.
It seems due to gargantuan size, I will not be going for the folded horn bass solution this summer or spring, because mainly for the size, but I would have to cut too many corners and would eventually be getting only halfway where I actually want to go, so it wouldn't necessarily be worth the money, time and mental bandwidth to experiment and create everything under those circumstances. I am not abandoning the idea, but I would like to get as close to what's theoretically possible when I do decide to do it.
@Crashpc I believe you have understood well where I'm coming from and perhaps even our sonic preferences and requirements align somewhat. Could you please share the BR box design that you decided to go with? Is there a thread or something else that I could refer to for more information?
This guy has a really interesting system I think. Maybe not necessarily for the highs, but everything from way down low to high mids are probably very good or stellar.
But, take a look at the sub. It's something very interesting. I didn't quite understand what was the arrangement there, is he saying that there is a driver cut out in the back just like we are seeing in the front facing the rear wall or are the two drivers basically in the same tube arrangement within the box which is itself sealed (no opening at the back). Well, it's really interesting, some kind of push-pull thing idea, but yeah, I wonder what you think about it.
@Crashpc I believe you have understood well where I'm coming from and perhaps even our sonic preferences and requirements align somewhat. Could you please share the BR box design that you decided to go with? Is there a thread or something else that I could refer to for more information?
But, take a look at the sub. It's something very interesting. I didn't quite understand what was the arrangement there, is he saying that there is a driver cut out in the back just like we are seeing in the front facing the rear wall or are the two drivers basically in the same tube arrangement within the box which is itself sealed (no opening at the back). Well, it's really interesting, some kind of push-pull thing idea, but yeah, I wonder what you think about it.
His sub is a sealed box - one driver on the front- one driver on the rear - they are wired to move in opposition so cancel out shaking forces and some even order harmonics
That's important with a fairly heavy moving mass and a 34mm xmax figure
https://www.caraudio.com/threads/tc-sounds-lms-r-ultra-5400-18-subwoofer-for-sale.614480/
That's important with a fairly heavy moving mass and a 34mm xmax figure
https://www.caraudio.com/threads/tc-sounds-lms-r-ultra-5400-18-subwoofer-for-sale.614480/