Good call!
Many years ago I had a similar issue with a bookshelf project using 7" Accutons in 15L sealed boxes. The sound clarity was pretty good overall, but to my ears there were some "subtle" high-Q resonances emanating from the box, but it wasn't the panels, and no amount of padding would absorb it. It's like the back-wave was screaming to be let out.
I've come to understand that with a hard cone, you need to do things a bit differently. Definitely make the box lossy (unless we're talking about bass with no resonances). Even with future dipole experiments, I plan to have a lossy buffer zone around the edge, with padded holes or something similar. Otherwise, edge diffraction could be quite harsh with such a powerful motor source. I would rather have it well-damped to start with, before resorting to EQing.
People forget that air impedance effects apply to ALL speakers, not just horns. And both inside and outside of the box. The wave-guide, AKA the entire exterior box shape (and the room at low freq) needs to promote smooth growth of the wave as it expands out from the cone.
On the electrical side, the typical "above 9000 dampings!!" voltage amplifier is just going to make matters worse. The trouble is that if you add series resistance or use a nice class-A with a low damping factor, a sealed box is going to have artefacts like comb filtering. Instead of resonating like crazy, the back-wave will leak out through the cone. We could stop here and live with the slight colouration.
But if you add pre-emptive digital correction to smooth out the response, it will lock the back-wave back in. It will 'correct' for the softness of the amplifier. Current control should still be more linear, but there doesn't seem to be any substitute for aperiodic venting.
As you wish I guess. but is not 3 woofers for middbass abit out of proportion... 3?
also puts one right close to the floor.
Personally I would do a 4 way...
and are these super costy drivers reaaalay thaaaaaaaaaaaat much better if at all? when compared to good quality ones. likely paying extra hundreds for a more stylish basket and cone but its still a acoustic pump really. gotta be a point in the market where you get to Good, and then a point where you are paying double or more for that extra >5-9%
well personally Im not that wealthy.
also puts one right close to the floor.
Personally I would do a 4 way...
and are these super costy drivers reaaalay thaaaaaaaaaaaat much better if at all? when compared to good quality ones. likely paying extra hundreds for a more stylish basket and cone but its still a acoustic pump really. gotta be a point in the market where you get to Good, and then a point where you are paying double or more for that extra >5-9%
well personally Im not that wealthy.
You are mad
Accuton C220-6-222 - Google Search
just a waste of drivers. if you insist on spending that stupidly much you may as well ommit the subs and use 3 of those for bass and lower mid. atleast you will be using the driver. bita a waste of drivers to use 3 to play a octave or so.. also I dont think you need 3? thats out of proportion. 1 would say one or 2. if using 2 for subs. but how can you justify such a costly speaker?
oh well. thats my 2 cents
Accuton C220-6-222 - Google Search
just a waste of drivers. if you insist on spending that stupidly much you may as well ommit the subs and use 3 of those for bass and lower mid. atleast you will be using the driver. bita a waste of drivers to use 3 to play a octave or so.. also I dont think you need 3? thats out of proportion. 1 would say one or 2. if using 2 for subs. but how can you justify such a costly speaker?
oh well. thats my 2 cents
One way this AS250-8-552 could be improved and made for less. would be if they where to make the radiating surface more within the speaker basket. If it was also made lighter. A smaller magnet and voice coil assembly could be used resulting in something that performs the same for a fraction of the cost.
....For Example/ Seas D1001-04S L26ROY 10 inch long stroke woofer | Loudspeaker freaks
I mean... Could you ''make do'', with four of these? for each cabinet. feel free to foward the difference, pm me your email and I can send you My Paypall information. I can buy some new trowsers.
I mean... Could you ''make do'', with four of these? for each cabinet. feel free to foward the difference, pm me your email and I can send you My Paypall information. I can buy some new trowsers.
I agree, and if you buy good parts they should be used well, because the design is important.
You can say that smaller is faster, but you use smaller at higher frequencies. This means they are the same, only different bands.3wayaddict said:
What will you achieve by this, maybe you will forget other things.3wayaddict said:
Good parts with good design leads to great results! Though spending 3K+ per speaker on just drivers might be a bit enthousiastic. If you look at the Kii 3. Wonderful speaker, uses $20 woofers and a $75 dollar tweeter (SEAS DXT).
Peerless by Tymphany SBS-160F35AL01-04 6-1/2" Aluminum Cone Woofer 4 Ohm
Time alignement is absolutely necesserary for a proper phase response. It would be straight up stupid to not do it if you are going the DSP route.
Ignoring it in the analog domain can be done, because then you have less control over your signal.
The point I have been trying to make is that OP should know what he wants performance wise. If he keeps going on like this he will just spend 23895739285793 euro's on drivers and not know what he wants. If he specifies the results he wants to achieve, he can work towards that goal. Going for your personal perfect sound kind of sounds like utopia to me. Simply because there is no perfect sound.
Adding more drivers lowers non-linear distortion and raises output power. It comes at the price of phase coherency, off axis response, physical size and of course price (although price kind of seems neglegible it seems). Is it really worth the extra money? You can even argue that you make the system worse by adding drivers.
Peerless by Tymphany SBS-160F35AL01-04 6-1/2" Aluminum Cone Woofer 4 Ohm
Time alignement is absolutely necesserary for a proper phase response. It would be straight up stupid to not do it if you are going the DSP route.
Ignoring it in the analog domain can be done, because then you have less control over your signal.
The point I have been trying to make is that OP should know what he wants performance wise. If he keeps going on like this he will just spend 23895739285793 euro's on drivers and not know what he wants. If he specifies the results he wants to achieve, he can work towards that goal. Going for your personal perfect sound kind of sounds like utopia to me. Simply because there is no perfect sound.
Adding more drivers lowers non-linear distortion and raises output power. It comes at the price of phase coherency, off axis response, physical size and of course price (although price kind of seems neglegible it seems). Is it really worth the extra money? You can even argue that you make the system worse by adding drivers.
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Yep, that's the same experience I had.It's like the back-wave was screaming to be let out.
I've come to understand that with a hard cone, you need to do things a bit differently. Definitely make the box lossy (unless we're talking about bass with no resonances).
Make a nice lossy aperiodic cabinet that let the backwave absorb and escape.
I draw them in TinkerCAD. It's a free online CAD program. It's not really that technical, not useful for use with advanced tools and such, but it is a very nice and easy way to design the boxes visually. You can easily get an idea of the way they will look.
About the system. Let's just make this a fantasy for a ultimate system. I'll ditch the MTM configuration.
I recently went to a demonstration of the new Vivid Audio Kaya series. And the designer explained some about the design. Very interesting and useful information. He really paid attention about the of axis response of the mid in comparison with the tweeter. How the mid can start rolling of off-axis approaching the crossover frequency where al of the sudden the tweeter has perfect off-axis response again, which is unfavourable.
On top of the designing that went into them, the speakers sound very good. Not only objectively, but also subjectively. I really liked the way the sound. The are very fast and offer beautiful transparency and a bright presentation (bright in a good way) and I've now decided I prefer hard cones and domes. So for the tweeter, I'll go for the Scan-Speak Revelator D2908/714000 but maybe actually the Illuminator D3004/664000. Unlike the Revelator, the Illuminator has the AirCirc motor design, which optimizes the internal aerodynamics of the motor. I think letting the dome breathe and optimizing the aerodynamics and acoustics of the motor might offer an advantage in naturality and soundstage which, mainly the second one, I'm really after. And I think the Illuminator might more represent the same kind of sound characteristic as Vivid than the Revelator. For the midrange, I do want some surface area to as high as possible, so I might have a Accuton C51-6-286 for upper midrange up to where it has perfect off-axis response, or 6 kHz at highest. For midrange I'll use the Accuton C168-6-990. This has a nice and big surface area, perfect off-axis response up to 2 kHz and most importantly that open-back (as I call it) motor design, making for no reflections behind the cone, letting it breathe completely free, in terms of soundstage, it doesn't get any better than that, and that with the sound quality and performance of ceramic Accutons. It will work to 2 kHz. The C90 actually has no advantage in higher frequencies over the C168. It's off-axis response starts rolling of above 2 kHz making it just as useless above that frequency as the C168 if you want perfect off-axis response, like I'm going for here.
For mid bass, I'll again use the C220-6-222, four of them. These I think I actually will place two above the mids and tweeter and two below (MB-MB-UM-T-M-MB-MB) because the consequences of this configuration are much less of a problem at these frequencies and it will allow the mid bass to really develop a big wavefront across the dimensions of the room, which is also a pretty important subject in this project (will get back to that later).
Then, the bass, now it's gonna get real exciting. Instead of built-in subwoofers. I'm gonna make use of corner-loading. This way, instead of the drivers having to fight with the room, and the reflection, I'll use the room to my advantage. My idea is put a room-high row of woofer in triangular sealed boxes to fit in the corners. This way, instead of the waves coming out of the woofer, traveling though the room, and hitting a wall and reflecting and bouncing around. The wave will come out of the room, and immediately travel amongst the walls, largely eliminating problems with reflection. And putting room-high rows of woofers in each corner of the front wall, will again make the woofers form one big, evenly spread wave travelling forward, instead of a wave traveling in all directions bouncing around. That way the woofers will fill the room, and the way the waves travel through it will make for a very fast, tight, punchy and overall just magical bass.
Though about the drivers. I could just use the Accuton AS250. But for this implementation, I got interested in using big professional or at least that high efficiency type driver subwoofers because the offer obviously extremely high efficiency, needing very kettle power to reach good listening levels and which will result in extremely low distortion. Most of them don't go very low by themselves, but putting so many in a room and corner-loading them will already help them to go a little lower. But mainly, these woofers are so powerfull and can reach such high SPL with minimal effort, that you can use DSP quite agressively to get them to go very low without them sounding stressed at all. And also very importantly, even though their large size, they are extremely fast. Even the Scan-Speak Revelator 28W subwoofer, which is the fastest hifi-subwoofer I've ever known of, isn't anywhere near as fast as even much larger let alone similar sized pro woofers.
The driver I mainly consider is the B&C Speaker 21SW152. 5 of them on top of each other in each corner, so that's 10 total in the room. It is the top of the line pro subwoofer from the brand and also on the market. It has huge sensitivity, extremely powerful motor, huge Sd of 1680 cm2, it can easily reach immense SPL, and it goes relatively low. These woofers are more than powerful enough to easily handle quite some DSP but I still try to get the woofers to work as low as possible by themselves. I know BMS makes pro woofers that are tuned to go quite a bit lower by themselves, but this goes at the cost of quite some speed. Though, still, this huge size, is significantly faster than even the Revelator subwoofer, it's about as fast as a Revelator 18W. Insane. This will offer phenomenal tightness, punch and speed.
Though, these woofers, especially when you have 10 of them in a room, might seem wonderful with their speed and power and huge Sd but does anyone know if the sound of these kind of woofers is actually favourable for a system like this? Do they actually sound good. Anyone has experience using these kinds of woofers for hifi?
About the system. Let's just make this a fantasy for a ultimate system. I'll ditch the MTM configuration.
I recently went to a demonstration of the new Vivid Audio Kaya series. And the designer explained some about the design. Very interesting and useful information. He really paid attention about the of axis response of the mid in comparison with the tweeter. How the mid can start rolling of off-axis approaching the crossover frequency where al of the sudden the tweeter has perfect off-axis response again, which is unfavourable.
On top of the designing that went into them, the speakers sound very good. Not only objectively, but also subjectively. I really liked the way the sound. The are very fast and offer beautiful transparency and a bright presentation (bright in a good way) and I've now decided I prefer hard cones and domes. So for the tweeter, I'll go for the Scan-Speak Revelator D2908/714000 but maybe actually the Illuminator D3004/664000. Unlike the Revelator, the Illuminator has the AirCirc motor design, which optimizes the internal aerodynamics of the motor. I think letting the dome breathe and optimizing the aerodynamics and acoustics of the motor might offer an advantage in naturality and soundstage which, mainly the second one, I'm really after. And I think the Illuminator might more represent the same kind of sound characteristic as Vivid than the Revelator. For the midrange, I do want some surface area to as high as possible, so I might have a Accuton C51-6-286 for upper midrange up to where it has perfect off-axis response, or 6 kHz at highest. For midrange I'll use the Accuton C168-6-990. This has a nice and big surface area, perfect off-axis response up to 2 kHz and most importantly that open-back (as I call it) motor design, making for no reflections behind the cone, letting it breathe completely free, in terms of soundstage, it doesn't get any better than that, and that with the sound quality and performance of ceramic Accutons. It will work to 2 kHz. The C90 actually has no advantage in higher frequencies over the C168. It's off-axis response starts rolling of above 2 kHz making it just as useless above that frequency as the C168 if you want perfect off-axis response, like I'm going for here.
For mid bass, I'll again use the C220-6-222, four of them. These I think I actually will place two above the mids and tweeter and two below (MB-MB-UM-T-M-MB-MB) because the consequences of this configuration are much less of a problem at these frequencies and it will allow the mid bass to really develop a big wavefront across the dimensions of the room, which is also a pretty important subject in this project (will get back to that later).
Then, the bass, now it's gonna get real exciting. Instead of built-in subwoofers. I'm gonna make use of corner-loading. This way, instead of the drivers having to fight with the room, and the reflection, I'll use the room to my advantage. My idea is put a room-high row of woofer in triangular sealed boxes to fit in the corners. This way, instead of the waves coming out of the woofer, traveling though the room, and hitting a wall and reflecting and bouncing around. The wave will come out of the room, and immediately travel amongst the walls, largely eliminating problems with reflection. And putting room-high rows of woofers in each corner of the front wall, will again make the woofers form one big, evenly spread wave travelling forward, instead of a wave traveling in all directions bouncing around. That way the woofers will fill the room, and the way the waves travel through it will make for a very fast, tight, punchy and overall just magical bass.
Though about the drivers. I could just use the Accuton AS250. But for this implementation, I got interested in using big professional or at least that high efficiency type driver subwoofers because the offer obviously extremely high efficiency, needing very kettle power to reach good listening levels and which will result in extremely low distortion. Most of them don't go very low by themselves, but putting so many in a room and corner-loading them will already help them to go a little lower. But mainly, these woofers are so powerfull and can reach such high SPL with minimal effort, that you can use DSP quite agressively to get them to go very low without them sounding stressed at all. And also very importantly, even though their large size, they are extremely fast. Even the Scan-Speak Revelator 28W subwoofer, which is the fastest hifi-subwoofer I've ever known of, isn't anywhere near as fast as even much larger let alone similar sized pro woofers.
The driver I mainly consider is the B&C Speaker 21SW152. 5 of them on top of each other in each corner, so that's 10 total in the room. It is the top of the line pro subwoofer from the brand and also on the market. It has huge sensitivity, extremely powerful motor, huge Sd of 1680 cm2, it can easily reach immense SPL, and it goes relatively low. These woofers are more than powerful enough to easily handle quite some DSP but I still try to get the woofers to work as low as possible by themselves. I know BMS makes pro woofers that are tuned to go quite a bit lower by themselves, but this goes at the cost of quite some speed. Though, still, this huge size, is significantly faster than even the Revelator subwoofer, it's about as fast as a Revelator 18W. Insane. This will offer phenomenal tightness, punch and speed.
Though, these woofers, especially when you have 10 of them in a room, might seem wonderful with their speed and power and huge Sd but does anyone know if the sound of these kind of woofers is actually favourable for a system like this? Do they actually sound good. Anyone has experience using these kinds of woofers for hifi?
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I really like the corner loading idea. Time alignment will be a bit trickier than usual, but the required excursion of each driver is significantly lower (lower excursion -> lower distortion).
10 drivers in a room seems a bit over the top. More drivers also need more volume. I am not really familiar with pro/PA drivers. Therefor I cannot judge on that. I'm more of a hifi/studio guy
Overall I think it is a great idea though!
10 drivers in a room seems a bit over the top. More drivers also need more volume. I am not really familiar with pro/PA drivers. Therefor I cannot judge on that. I'm more of a hifi/studio guy
Overall I think it is a great idea though!
The number of drivers isn't about power handling or getting loud. It's about surface area and mainly just getting the row of woofers as high as the room. Volume isn't that big of an issue. Especially in sealed boxes, you won't need that big of a box. Surprisingly, in particular these pro woofers only need relatively tiny boxes. These 21"s only need 52 L per driver.
I looked a bit deeper into pro woofers in comparison to hifi woofers. I think in this case hifi woofers are the better choice. I looked at some measurements and to my surprise even the top of the line B&C 18 and 21"s have quite a lot of distortion relative to hifi woofers. They tend to top 2 or even 3%. Which, even considering their higher sensitivity is much more than hifi woofers, the Scan-Speak Revelator 32W for example, let alone the Accuton AS250. On top of that. I've red that pro woofers, unless they're designed for studio use, aren't designed to really sound accurate or transparent and all the other things you want in hifi, and so they don't.
And, because this is a ultimate fantasy, in case I will use the Accuton AS250s and make a room-high row of them, I will have 10 of them in each corner, 20 in total in the room. Twice as many as I would have 21"s. Depending on the way I wire them, this will give them 6 dB more sensitivity, which brings them back closer to that of the pro drivers. On top of that, the hifi woofers go much lower by them selves, reducing the amount of DSP-ing required to get them to go as low, which again reduces stress on the drivers and so distortion. And you're not forcing the drivers to do things they don't want to as much. Which makes a definitely perceivable difference.
So in the end, hifi woofers (20 Accuton AS250s in this case) will have less distortion, will go lower naturally. And in the way the sound, in terms of naturality, accuracy and sound quality in general hifi woofers are much more desirable. And then finally: speed. Technically pro woofers will remain the fastest. But that doesn't make the best hifi woofers in the world slow by any means. The Accuton drivers are still some of the quickest and tightest woofers in the world. Especially in sealed enclosures, in this corner loading I'm talking about with al it's consequences, these woofers will be tremendously quick.
So yeah, it's gonna be about 10 Accuton AS250s in each corner.
And, because this is a ultimate fantasy, in case I will use the Accuton AS250s and make a room-high row of them, I will have 10 of them in each corner, 20 in total in the room. Twice as many as I would have 21"s. Depending on the way I wire them, this will give them 6 dB more sensitivity, which brings them back closer to that of the pro drivers. On top of that, the hifi woofers go much lower by them selves, reducing the amount of DSP-ing required to get them to go as low, which again reduces stress on the drivers and so distortion. And you're not forcing the drivers to do things they don't want to as much. Which makes a definitely perceivable difference.
So in the end, hifi woofers (20 Accuton AS250s in this case) will have less distortion, will go lower naturally. And in the way the sound, in terms of naturality, accuracy and sound quality in general hifi woofers are much more desirable. And then finally: speed. Technically pro woofers will remain the fastest. But that doesn't make the best hifi woofers in the world slow by any means. The Accuton drivers are still some of the quickest and tightest woofers in the world. Especially in sealed enclosures, in this corner loading I'm talking about with al it's consequences, these woofers will be tremendously quick.
So yeah, it's gonna be about 10 Accuton AS250s in each corner.
To be honest, 2-3% distortion all way towards 20Hz is remarkable. It is not strange for a subwoofer to have distortion numbers in the 10's of %.
Do you have a space constraint? Stacking 10x 11" woofers is about 2.75 meters high and that is with 0mm spacing in between them. Though you could put the woofers side by side. The box will be HUGE though.
Doubling the amount of drivers is only going to half the amount of distorion. Considering that this dream set up is going to be 25k just in woofers alone is quite significant.
If non-linear distortion and step response is what you're going after, motion feedback might be the way to go.
If space isn't a problem, you could also make HUGE horns!
Do you have a space constraint? Stacking 10x 11" woofers is about 2.75 meters high and that is with 0mm spacing in between them. Though you could put the woofers side by side. The box will be HUGE though.
Doubling the amount of drivers is only going to half the amount of distorion. Considering that this dream set up is going to be 25k just in woofers alone is quite significant.
If non-linear distortion and step response is what you're going after, motion feedback might be the way to go.
If space isn't a problem, you could also make HUGE horns!
The distortion of the 21" B&C actually rockets up below 40, especially 30 Hz hitting over 10 % at 20 Hz. The Scan-Speak 32W/4878T00 however stays well under 2,5 - 2% at 20 Hz.
Space constraint isn't really a thing, considering this is a ultimate fantasy. I'm just considering a room between 2,5 and 3 m high. If I were to actually do this. I won't make one big cabinet, I'll have separate passive modules each with one woofer in them. So I can stack whatever number depending on the room.
I've looked at some more drivers and do you think matching paper cone (sub)woofers with ceramic and metal above it in terms of sound characteristic be a problem? I don't think that much if at all right right? Choices in (sub)woofers with aluminum cones actually are surprisingly limited. Quite a lot of the best subs on the market use paper based cones.
I would actually really like to use the Scan-Speak Revelator 32W/4878T00 as subs for this system. It doesn't really get any lower in terms of distortion, it's quite efficient, it's tremendously quick, even quicker than the Accuton AS250. It actually copes with the speed of some 7" mids like the Revelator 18W. And it goes lower naturally because it's bigger than the AS250 and designed as a subwoofer. The AS250 actually is a woofer, it goes low for a woofer of it's size and is the highest quality on the market, but it still is only a 10" woofer. I would like to use bigger, lower going subwoofers of the same quality, which the 32W is.
Space constraint isn't really a thing, considering this is a ultimate fantasy. I'm just considering a room between 2,5 and 3 m high. If I were to actually do this. I won't make one big cabinet, I'll have separate passive modules each with one woofer in them. So I can stack whatever number depending on the room.
I've looked at some more drivers and do you think matching paper cone (sub)woofers with ceramic and metal above it in terms of sound characteristic be a problem? I don't think that much if at all right right? Choices in (sub)woofers with aluminum cones actually are surprisingly limited. Quite a lot of the best subs on the market use paper based cones.
I would actually really like to use the Scan-Speak Revelator 32W/4878T00 as subs for this system. It doesn't really get any lower in terms of distortion, it's quite efficient, it's tremendously quick, even quicker than the Accuton AS250. It actually copes with the speed of some 7" mids like the Revelator 18W. And it goes lower naturally because it's bigger than the AS250 and designed as a subwoofer. The AS250 actually is a woofer, it goes low for a woofer of it's size and is the highest quality on the market, but it still is only a 10" woofer. I would like to use bigger, lower going subwoofers of the same quality, which the 32W is.
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What do you think about using six C173-6-096s instead of four C220-6-222s? Even six of them have a little less Sd than four C220s but obviously it's still huge. Though they allow for a sleeker cabinet and mainly, are even much faster. The C220s already are extremely fast but I would like to try and get the absolute best possible transient response. Though, they don't go very low. In a sealed box they will have a F3 of 170~180 Hz. Because of the effects of such a large number in a room and of course with a little help of DSP they will go a little lower but the crossover to the subs will have to be higher, around 170 Hz. Do you think this should be possible? Phase and speed and the way waves coming from the subs are well controlled by the way I'll implement them and in theory they should more than easily handle such frequencies but will it be favorable? If not and the crossover will really have to be 100 Hz or lower, I might better stick with the C220. I could make the C173s ported but this way they will be a periodic system and will lose they'll lose the advantage in speed they have. A passive radiator will have a little more speed in the initial hit of a tone but will still be periodic and slightly slower in the end. However, passive radiators will add a little nice weight to the sound but this will be the same for just using the bigger C220s.
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