Hello,
I'm starting with my own DIY speaker project. I've been reading a lot on cabinet design and calculations. When i look at some of the docking/Bluetooth/multi-room speakers i wonder if they follow the same rules. the cabinets seem so small. Do those manufacturers just create something that looks good or do they do speaker measurements as well?
Just curious about that.
cheers
I'm starting with my own DIY speaker project. I've been reading a lot on cabinet design and calculations. When i look at some of the docking/Bluetooth/multi-room speakers i wonder if they follow the same rules. the cabinets seem so small. Do those manufacturers just create something that looks good or do they do speaker measurements as well?
Just curious about that.
cheers
Having never been in the designers roundtable for such devices, I would tend to think, sound quality is very much on the bottom of the list of priorities.
Production volumes, cost per unit...cutting costs per unit, "How are we doing Sam, have you managed to find me that eleven cents per unit?...I'll take nine ....but I want that eleven!"....for a driver being manufactured by the thousands, per day, at a cost of $0.73 per unit......This is not even taking into account the enclosure...that is in a different factory.
So that 3.5 inch driver has little, if any, forethought to its "accuracy", ......now, why is this $0.73 unit somewhat similar looking to that $17.21 unit?....because they spent buckets of money actually engineering the thing.
---------------------------------------------------------------------Rick............
Production volumes, cost per unit...cutting costs per unit, "How are we doing Sam, have you managed to find me that eleven cents per unit?...I'll take nine ....but I want that eleven!"....for a driver being manufactured by the thousands, per day, at a cost of $0.73 per unit......This is not even taking into account the enclosure...that is in a different factory.
So that 3.5 inch driver has little, if any, forethought to its "accuracy", ......now, why is this $0.73 unit somewhat similar looking to that $17.21 unit?....because they spent buckets of money actually engineering the thing.
---------------------------------------------------------------------Rick............
Hi Cypress,
Those full-range mini-drivers follow the same physics, but they are purpose built as wide range drivers.
Here is one of MANY examples:
https://www.parts-express.com/dayto...luminum-cone-full-range-driver-8-ohm--290-210
I also think Bose "wave" is a glorified transmission line enclosure.
Best,
Erik
Those full-range mini-drivers follow the same physics, but they are purpose built as wide range drivers.
Here is one of MANY examples:
https://www.parts-express.com/dayto...luminum-cone-full-range-driver-8-ohm--290-210
I also think Bose "wave" is a glorified transmission line enclosure.
Best,
Erik
Docking/Bluetooth/multi-room speakers have to be small, so they heavily rely on DSP (or should rely on). They follow the same rules (with many exclusions, of course). Some of them measure and sound pretty good. The best source of sound tests and measurements of bluetooth speakers is
https://www.youtube.com/user/clavinetjunkie
https://www.youtube.com/user/clavinetjunkie
They use some tricks to obtain a more impressive sound. Sonos Play:1 for example uses a mild boost at the mid bass to sound full. In reality it stops at 88 Hz (-3 dB).
Measurement: https://www.lifewire.com/sonos-play-1-measurements-3134601
Some sound docks generate harmonics of bass but do not play the fundamental itself, so they trick your ears into thinking they produce bass.
Measurement: https://www.lifewire.com/sonos-play-1-measurements-3134601
Some sound docks generate harmonics of bass but do not play the fundamental itself, so they trick your ears into thinking they produce bass.
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I have heard a Sonos play 5 in person and it is impressive. The perception of good sound quality is certainly something they did right and they achieve it using high technology. You could not touch it or have any hopes of making a speaker yourself that was that small and sounded that good. It has three 1in soft dome tweeters in waveguides, three 5in bass drivers and uses long throw excursion custom drivers, a lot of DSP and EQ. But for a small sealed box that is small like that - the bass is quite deep. The highs are very clear and mids were acceptable. My guess is a solid 50Hz and probably pretty flat frequency response with exception to bass EQ boost. I wouldn't write them off as not paying attention to SQ. Go listen to one and you will see that if you bought $500 worth of drivers you can't do what they do for that size box.
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xkr971 - you are completely right. With a small correction: the Sonos Play 5 actually is ported. Porting results in 'free' extra bass, though more EQ is required to correct for the mid bass hump that is typical for undersized ported enclosures. Those speakers are EQ'ed anyway, so that is not a problem.
Even the tiny JBL Go is ported (40 mm driver, 0,17 L exterior volume).
Even the tiny JBL Go is ported (40 mm driver, 0,17 L exterior volume).
I looked real hard and could not find the port on it. I know the earlier gen 1 was ported but can you show me where port is on gen 2 Sonos Play 5?
Generally, sound quality is at the bottom of the priority except for 2 companies, Sonos, and maybe Bose. Sonos is a strange company because when everyone else ignores sound quality, they place sound quality as a HUGE priority and has technology inside that we simply cannot touch with DIY.
The Sonos Play 1 and Gen 2 Play 5 is a far better and far better engineered speaker than most people expect. The Play 5 is an all out effort to create the best sounding small speaker, and it blows my mind that it only costs $500. I'll try to give an idea of the engineering that went into the Sonos. Why do I know this? Because I spent a significantly amount of effort trying to create a great sounding small speaker, so of course when I see something as good as the Sonos, I study it.
I'll answer your questions first in a simplistic fashion first and explain more and more in detail.
Much of the speaker design rules around cabinet size you read refers to passive speakers. These rules can be bent for active speakers through EQ and enough amp power and power handling on the driver.
Most small speakers measure horribly because sound quality is not really a concern. Not the Sonos. The Sonos measures so well it is about as good as it gets.
In the next post, I'm going to explain why Sonos is far better than any other small speaker on the market and how just well designed it is.
The Sonos Play 1 and Gen 2 Play 5 is a far better and far better engineered speaker than most people expect. The Play 5 is an all out effort to create the best sounding small speaker, and it blows my mind that it only costs $500. I'll try to give an idea of the engineering that went into the Sonos. Why do I know this? Because I spent a significantly amount of effort trying to create a great sounding small speaker, so of course when I see something as good as the Sonos, I study it.
I'll answer your questions first in a simplistic fashion first and explain more and more in detail.
Much of the speaker design rules around cabinet size you read refers to passive speakers. These rules can be bent for active speakers through EQ and enough amp power and power handling on the driver.
Most small speakers measure horribly because sound quality is not really a concern. Not the Sonos. The Sonos measures so well it is about as good as it gets.
In the next post, I'm going to explain why Sonos is far better than any other small speaker on the market and how just well designed it is.
I'm going to make a bold statement: The Sonos Play 5 is the most well designed small speaker ever made through high quality drivers, smart enclosure design, and masterful use of DSP.
Let's look at the components.
Bass: Sonos uses triple 4'' woofers in each Play 5. They are much larger than the typical 4'' because driver diameters are based on frame to frame diameter, so the actual cone diameter is smaller. Sonos engineered the frame to be minimized to the point the frame diameter is essentially the cone diameter to squeeze as much woofer into the small speaker as possible, so in reality the 4'' woofer has the surface area of a 5''.
For some reason the images are compressed. Click on the image for the proper size.
One look at that driver and you know this is no cheap driver. In fact, the quality is exceptionally high for a driver of this size. It is an expensive underhung woofer in order to achieve high linear excursion needed for bass.
Waveguided tweeter
Sonos wanted to make a small speaker sound big. The result is a complicated solution using a specially designed waveguided 3 tweeter array to control the high frequency beamwidth. I actually don't know too much about the waveguide. It is a design I've never seen before.
Sonos Play 5 design
Sonos chose a 6 driver, triple tweeter and triple 4'' woofer design for the Play 5. This is the optimal design for Sonos's goal of the best sounding all in one small speaker many reasons. I'll analyze each speaker performance goal and how the Play 5 performs.
Bass: The challenge of small speakers is limited bass output and extension due to physics. Sonos bent the laws of physics as far as possible by using triple high excursion 5'' woofers in a sealed box. Then they used EQ to boost the bass for a F3 point of 27Hz! While it doesn't have much usable output that low, it certainly has usable output down to around 35Hz, and it capable of playing 50Hz quite loudly. This is possible due to the woofer's very high linear excursion from the high quality motor.
Why is sealed optimal? A port will not work in a box so small, and it would severely limit the bass extension and low bass output. Passive radiators can be tuned low enough, but in such a small enclosure only about 2dB of output gain can be achieved, and it would cause massive group delays (several times above the 1 cycle limit for 20dB+ boosts) due to the huge bass boost filters used. Not to mention there is no space for passive radiators in the box, unless a woofer is removed, which would reduce output more than a passive radiator would gain. Therefore, a sealed design is more accurate and does not sacrifice much output.
Why don't we boost the bass on all speakers to extend the bass extension?
The problem of bass equalization boost to extend a speaker's bass response is that the speaker quickly distorts as the volume goes up because the huge bass boost causes the woofer to go past its limit much faster than it normally would. Sonos (and others) uses a limiter to prevent the bass from getting louder as the volume gets too high. This way the volume can go up, but the bass stops getting louder, so the speaker does not distort because of excessive bass.
However, not all limiters are the same. Most speakers that have limiters use a single band limiter. This means that when there is too much bass, it lowers the volume of the entire sound during that bass hit. This is called pumping, where the volume goes up and down because of the bass. Fancy speakers have a multi-band compressor, which separates the audio into multiple bands to reduce the effects of pumping by only lowering the bass band and leave the midrange and treble alone. This has some sound quality problems, and it is a bit complicated to explain why.
Sonos uses a sliding high pass limiter, and it is exactly like it sounds. It will place the high pass depending on the volume so the woofer limits isn't exceeded. On volumes where the woofer will not exceed limits, it is set at 30Hz. As the volume goes higher, the high pass is set higher and higher. This kind of limiter has the least distortion among all limiters. Again, this shows how much Sonos cares about the accuracy of the speaker.
Why triple smaller woofers instead of 2 or one bigger woofer?
Dynamics. Using 3 woofers instead of 1 or 2 bigger woofer of the same total surface area have the advantage of higher output everywhere above midbass where excursion is not the limiting factor for maximum output. This means the triple woofer will have quite a bit higher maximum volume in the midrange.
Note, the triple high quality woofer design is a lot more costly than the one big woofer approach many companies use. Not only there's 3 woofers, but each woofer is more expensive because the smaller woofer has to be of a higher quality to achieve the same performance as a bigger woofer. I wouldn't be surprised if each woofer in the Play 5 is much more expensive than the single bigger woofer in other small speakers. Now multiply that cost by 3.
Why the triple tweeter array? This is for multiple reasons. One big reason is because Sonos wants excellent off axis performance, since their speakers are going to be placed somewhere and listened to everywhere in the room. They do that by using very low crossovers point for a frequency at 1/2 wavelength of the center to center spacing of the tweeter and midrange. This corresponds to a sub 2000Hz crossover. But, small tweeters often struggle to cross that low, especially inexpensive tweeters, which will limit the speaker's dynamics. The solution is to use 3 of them for more output, and put 2 of them in waveguides, which will provide even more output, and the combination will have more output than any single direct radiating tweeter.
But I never see multiple tweeters in other speakers? That's because multiple tweeters is a bad idea because of comb filtering, where the tweeter's output cancels each other because the wavelength of high frequencies is so much larger than the size of the tweeter itself. Sonos went through the painstaking effort to make a special waveguide to control the radiation pattern of the tweeter. But that's not enough. Then they use DSP to create artificial frequency dependent phase shift for each tweeter channel to make sure the 3 tweeters are not interfering with each other. The result does not only solve comb filtering, but it controlled and widened the dispersion pattern of the high frequencies of the speaker, which has the effect of making the speaker sound bigger than it actually is and a wider stereo separation, and it allows for a low crossover point for excellent off axis performance while having better dynamic range as it plays much cleaner and louder than a single tweeter can.
This is the frequency response of the Play 5 with reduced treble. On normal treble it is just a completely flat frequency response.
The result? An incredibly good sounding small speaker that measures extremely well. It is a small stereo speaker that has deep, clean bass, reasonably loud bass, excellent dynamics, superb off axis performance, and of course ruler flat frequency response. There's not much else to improve on. Frankly, most speakers don't hit as many good speaker performance criterias as the Play 5, especially in regards to off axis performance, diffraction control, frequency response, and bass extension. The sound quality can easily compete (and outperform) many $1000 bookshelf speakers. and no bookshelf speaker is going to touch the bass performance of the Play 5.
I commend Sonos for putting so much effort into making a fantastic small speaker. In a world where many companies making small speakers fight to shave off mere cents in production costs, kudos to the Sonos business team to allow the engineering team to allocate not just a few cents more, but tens of dollars more to use such expensive quality components in a relatively inexpensive $500 speaker that would normally be more in line for speakers costing 3x more. Sonos knocked it out of the park, and frankly, the world with the Play 5.
Let's look at the components.
Bass: Sonos uses triple 4'' woofers in each Play 5. They are much larger than the typical 4'' because driver diameters are based on frame to frame diameter, so the actual cone diameter is smaller. Sonos engineered the frame to be minimized to the point the frame diameter is essentially the cone diameter to squeeze as much woofer into the small speaker as possible, so in reality the 4'' woofer has the surface area of a 5''.
For some reason the images are compressed. Click on the image for the proper size.
One look at that driver and you know this is no cheap driver. In fact, the quality is exceptionally high for a driver of this size. It is an expensive underhung woofer in order to achieve high linear excursion needed for bass.
Waveguided tweeter
Sonos wanted to make a small speaker sound big. The result is a complicated solution using a specially designed waveguided 3 tweeter array to control the high frequency beamwidth. I actually don't know too much about the waveguide. It is a design I've never seen before.
Sonos Play 5 design
Sonos chose a 6 driver, triple tweeter and triple 4'' woofer design for the Play 5. This is the optimal design for Sonos's goal of the best sounding all in one small speaker many reasons. I'll analyze each speaker performance goal and how the Play 5 performs.
Bass: The challenge of small speakers is limited bass output and extension due to physics. Sonos bent the laws of physics as far as possible by using triple high excursion 5'' woofers in a sealed box. Then they used EQ to boost the bass for a F3 point of 27Hz! While it doesn't have much usable output that low, it certainly has usable output down to around 35Hz, and it capable of playing 50Hz quite loudly. This is possible due to the woofer's very high linear excursion from the high quality motor.
Why is sealed optimal? A port will not work in a box so small, and it would severely limit the bass extension and low bass output. Passive radiators can be tuned low enough, but in such a small enclosure only about 2dB of output gain can be achieved, and it would cause massive group delays (several times above the 1 cycle limit for 20dB+ boosts) due to the huge bass boost filters used. Not to mention there is no space for passive radiators in the box, unless a woofer is removed, which would reduce output more than a passive radiator would gain. Therefore, a sealed design is more accurate and does not sacrifice much output.
Why don't we boost the bass on all speakers to extend the bass extension?
The problem of bass equalization boost to extend a speaker's bass response is that the speaker quickly distorts as the volume goes up because the huge bass boost causes the woofer to go past its limit much faster than it normally would. Sonos (and others) uses a limiter to prevent the bass from getting louder as the volume gets too high. This way the volume can go up, but the bass stops getting louder, so the speaker does not distort because of excessive bass.
However, not all limiters are the same. Most speakers that have limiters use a single band limiter. This means that when there is too much bass, it lowers the volume of the entire sound during that bass hit. This is called pumping, where the volume goes up and down because of the bass. Fancy speakers have a multi-band compressor, which separates the audio into multiple bands to reduce the effects of pumping by only lowering the bass band and leave the midrange and treble alone. This has some sound quality problems, and it is a bit complicated to explain why.
Sonos uses a sliding high pass limiter, and it is exactly like it sounds. It will place the high pass depending on the volume so the woofer limits isn't exceeded. On volumes where the woofer will not exceed limits, it is set at 30Hz. As the volume goes higher, the high pass is set higher and higher. This kind of limiter has the least distortion among all limiters. Again, this shows how much Sonos cares about the accuracy of the speaker.
Why triple smaller woofers instead of 2 or one bigger woofer?
Dynamics. Using 3 woofers instead of 1 or 2 bigger woofer of the same total surface area have the advantage of higher output everywhere above midbass where excursion is not the limiting factor for maximum output. This means the triple woofer will have quite a bit higher maximum volume in the midrange.
Note, the triple high quality woofer design is a lot more costly than the one big woofer approach many companies use. Not only there's 3 woofers, but each woofer is more expensive because the smaller woofer has to be of a higher quality to achieve the same performance as a bigger woofer. I wouldn't be surprised if each woofer in the Play 5 is much more expensive than the single bigger woofer in other small speakers. Now multiply that cost by 3.
Why the triple tweeter array? This is for multiple reasons. One big reason is because Sonos wants excellent off axis performance, since their speakers are going to be placed somewhere and listened to everywhere in the room. They do that by using very low crossovers point for a frequency at 1/2 wavelength of the center to center spacing of the tweeter and midrange. This corresponds to a sub 2000Hz crossover. But, small tweeters often struggle to cross that low, especially inexpensive tweeters, which will limit the speaker's dynamics. The solution is to use 3 of them for more output, and put 2 of them in waveguides, which will provide even more output, and the combination will have more output than any single direct radiating tweeter.
But I never see multiple tweeters in other speakers? That's because multiple tweeters is a bad idea because of comb filtering, where the tweeter's output cancels each other because the wavelength of high frequencies is so much larger than the size of the tweeter itself. Sonos went through the painstaking effort to make a special waveguide to control the radiation pattern of the tweeter. But that's not enough. Then they use DSP to create artificial frequency dependent phase shift for each tweeter channel to make sure the 3 tweeters are not interfering with each other. The result does not only solve comb filtering, but it controlled and widened the dispersion pattern of the high frequencies of the speaker, which has the effect of making the speaker sound bigger than it actually is and a wider stereo separation, and it allows for a low crossover point for excellent off axis performance while having better dynamic range as it plays much cleaner and louder than a single tweeter can.
This is the frequency response of the Play 5 with reduced treble. On normal treble it is just a completely flat frequency response.
The result? An incredibly good sounding small speaker that measures extremely well. It is a small stereo speaker that has deep, clean bass, reasonably loud bass, excellent dynamics, superb off axis performance, and of course ruler flat frequency response. There's not much else to improve on. Frankly, most speakers don't hit as many good speaker performance criterias as the Play 5, especially in regards to off axis performance, diffraction control, frequency response, and bass extension. The sound quality can easily compete (and outperform) many $1000 bookshelf speakers. and no bookshelf speaker is going to touch the bass performance of the Play 5.
I commend Sonos for putting so much effort into making a fantastic small speaker. In a world where many companies making small speakers fight to shave off mere cents in production costs, kudos to the Sonos business team to allow the engineering team to allocate not just a few cents more, but tens of dollars more to use such expensive quality components in a relatively inexpensive $500 speaker that would normally be more in line for speakers costing 3x more. Sonos knocked it out of the park, and frankly, the world with the Play 5.
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I had a tour of the Sonos office and got to speak with several engineers. But one can figure all this out if they bought one, measured it, and teared it down.
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"One look at that driver and you know this is no cheap driver. In fact, the quality is exceptionally high for a driver of this size. It is an expensive underhung woofer in order to achieve high linear excursion needed for bass."
Underhung? Not from what I see in the photo. You can easily see the voice coil windings extending above the magnet structure, and the top plate looks too thin for underhung geometry. As for "no cheap driver" it looks pretty generic to me. Stamped truncated chassis, nothing special. The question would be whether they put any fancy stuff in the motor like shorting rings, etc. Not saying it's a bad design, just doesn't strike me as anything all that unique.
Underhung? Not from what I see in the photo. You can easily see the voice coil windings extending above the magnet structure, and the top plate looks too thin for underhung geometry. As for "no cheap driver" it looks pretty generic to me. Stamped truncated chassis, nothing special. The question would be whether they put any fancy stuff in the motor like shorting rings, etc. Not saying it's a bad design, just doesn't strike me as anything all that unique.
You're right. I noticed that too, but I can't edit my post anymore. Weird, the Play 1 driver did not have the voice coils exposed like that, and I thought it was an underhung, so I assumed the same for the Play 5 since it is supposed to be an upgraded driver.
While it is not a looker with the stamped basket, it is the performance that counts, and clearly they put the money where the performance matters. Because really, a cast basket does do much for performance for a small driver. Sonos also spent a lot of effort taking advantage of their massive scale to do techniques that simultaneously increase performance and cut cost that can only be done with massive scale, but I'm not allowed to talk about that.
Go listen to one. No cheap driver, in fact, I'd go so far as to say unless it is an exceptionally good 4'' driver, it isn't belting out the kind of clean loud 40Hz in a sealed box like the Play 5 is.
Hope its ok for me to point to another example:
Recently my wife bought a 2016 Mazda CX5, she insisted on the Boss system it came with.
I criticized saying that was just overpriced mass market junk.
But once the system broke in, the SQ of the Boss system in the Mazda is breath taking.
I dont know whats going on in there, but it offers great bass, clear imaging and engulfing sound with clarity and details. I do observe that some sounds appear unnatural.
Now i am on the receiving end, my 4way DSP active loudspeaker with all Seas Excel drivers, Hypex Ncore amps and es9018 DAC isnt good enough for her 🙁
Recently my wife bought a 2016 Mazda CX5, she insisted on the Boss system it came with.
I criticized saying that was just overpriced mass market junk.
But once the system broke in, the SQ of the Boss system in the Mazda is breath taking.
I dont know whats going on in there, but it offers great bass, clear imaging and engulfing sound with clarity and details. I do observe that some sounds appear unnatural.
Now i am on the receiving end, my 4way DSP active loudspeaker with all Seas Excel drivers, Hypex Ncore amps and es9018 DAC isnt good enough for her 🙁
Another interesting article, regarding a Sony bluetooth speaker, and some DSP processing in it. Includes measurements. Oluv's Gadgets: Review: Sony SRS-X33 - who is going to be killed this time?
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