What are Subwoofers and Why Do You Need One?

LEARN ABOUT THE BEST SPEAKERS FOR HOME THEATER>

If you’re slowly starting to build your home theater system, the first thing you probably picked out was a pair of speakers. This is only the beginning, though. Whether your setup is for movies, music, games, or all of the above, a powered subwoofer is one of the key components of a complete audio system.

We’re here to answer some common questions about subwoofers and how they can elevate your home theater experience.

What is a Subwoofer?

In the words of Meghan Trainor, a subwoofer is all about that bass. It’s the speaker that delivers the lower frequencies – specifically 20-200 Hz – that a traditional two-channel or surround sound setup can’t reproduce on its own. These low frequencies come from instruments such as the kick drum, bass guitar, and pipe organ, as well as movie sound effects like explosions.

Why Do I Need One?

While you may hear the bass from your bookshelf or floorstanding speakers, a subwoofer allows you to feel the sound. Listening to bass-heavy music like hip hop or EDM or watching a full-throttle action flick without a subwoofer leaves a lot to be desired. Plus, you’re not experiencing the song or movie the way the artist or director intended.

You might be asking yourself: I don’t listen to rap or watch action movies, so why do I need one?

Sure, a subwoofer is a bass-thumping juggernaut, but that’s only scratching the surface. A great subwoofer helps take away the heavy lifting from your loudspeakers, improving your overall system.

The dynamics are more compelling, the soundstage widens, and the stereo imaging becomes more accurate. Even if you prefer spinning folk records and watching dialogue-driven indie dramas, a subwoofer helps produce a more vibrant, all-encompassing sound.

Where Do I Place a Subwoofer?

Honestly, you can place your subwoofer anywhere. But since all rooms are constructed differently, the results are going to vary. If you’re serious about getting optimal bass performance from your subwoofer, there may be some trial and error involved.

We get it. Not everyone has a dedicated home theater or listening room with the flexibility to place your subwoofer anywhere. Most likely, your system is located in your living room, which means décor, furniture, and other things are competing for floor space. You might have to rearrange some stuff, but it’s worth it to find the “sweet spot.”

Along with placement, acoustic treatment is another factor to consider if you want to get the most out of a subwoofer. You can have the best subwoofer on the planet, but when it’s in an acoustically poor room, expect subpar bass performance. Acoustic panels, diffusers, and bass traps are all excellent ways to improve your room’s acoustics. Plus, many modern A/V receivers come equipped with room correction technology such as Audyssey and AccuEQ. It calibrates each speaker to create a more harmonious home theater experience.

Downfiring vs Front-Firing Subwoofers:

Placement can also be determined by whether you’ve opted for a down-firing or front-firing subwoofer. While there’s no discernible difference between how each option sounds, there are certain factors you need to evaluate depending on the space you’re looking to fill, specifically whether you’re placing the sub in a home or an apartment.

Shop Subs Now

How Do I Dial-in My Subwoofer?

A subwoofer works best when it doesn’t draw attention to itself. Your subwoofer and loudspeakers should act as one unit. The bass coming from the subwoofer should blend seamlessly with the rest of your speakers.

On the back of our subwoofers, you’ll find a low-pass crossover knob. Crossover is the frequency where your speakers begin to roll-off, and the subwoofer starts to produce bass notes. Set your crossover point about 10 Hz above your speaker’s lowest frequency range. For example, 34 Hz is the lowest frequency the Next-Gen Reference R-800F can handle, so you would set your crossover at around 45 Hz.

The 0/180-degree phase switch is another subwoofer control. The mechanics behind the phase can get pretty complicated. In layman’s terms, subwoofers and speakers perform best when their woofers move forward and backward in a synchronized fashion. When they don’t, the speakers and subwoofer are out of phase, which cancels out the bass. To dial in your phase, play some bass-heavy music, listen for a bit, and have a friend switch between both settings. Whichever one sounds better, leave it there. If you can’t hear a difference, set it at 0 degrees.

Should I Get More Than One?

A large subwoofer like the RP-1600SW can take any home-theater setup to the next level. However, as your system grows, adding a second sub can help ensure the bass is evenly distributed throughout the whole room. Two RP-1600SWs increase your output capability, meaning everyone in the room can feel those powerful, low tones while watching action and sci-fi movies.

A pair of subwoofers can also minimize the seat-to-seat variance of bass response, offering an even coverage pattern of low frequencies throughout the room. Depending on room size and placement, one sub alone makes it challenging to deliver accurate bass responses at multiple listening positions. This is because the frequency response of an individual subwoofer tends to have peaks and nulls. A peak is an exaggeration of a bass note, while a null is the absence of bass. When paired together, two subwoofers smooth out those peaks and nulls, offering a more accurate frequency response at more locations in the room.

All in all, a subwoofer is an essential part of your system. If you’re on a budget or in the infancy of your home-theater development, start with just one subwoofer. As your system grows, think about adding a second low-toned beast to your setup. You’re adding more bass and evenly distributing it throughout the room. The results? Improved bass performance.

Are you looking to dive deeper? Read our other subwoofer post that touches on construction, wattage, and wired vs. wireless subwoofers

Soundwoofer – Free Impulse Response Library

Not everyone has access to expensive amplifier speakers and impulse responses are the “spirit” of those physical devices in a digital format.

We belive that the ability to produce a great sound should be available to everyone.

So we built a library where we, as a community can collect them all.

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Recent updates

Custom samples are here

2020-04-07

You can now upload your own sample

This update allows you to upload your own sample that you use to preview impulses with.
Keep in mind that the sample you choose must be recorded in a special way.
Heres a guide on how to do that

To upload a sample head to your profile page, after you have done that you can select your own sample in the ‘Select genre’-dropdown list.

We are aware that there might be some performance issues here and we are currently working on that

Enjoy!

Become a contributor – earn a pack

2020-02-08

Two library packs are available for bulk download.

We have received feedback about how useful it would be if the library was available for download as packs and we agree.
So, therefore we have made two packs available.

In order for you to get access to them we need something in return.

Pack one – Contains 350+ Impulses and can be found in your profile after you have logged in.

Pack two – Contains 1185 impulses and can be found in your profile after you have uploaded an Impulse of your own to the library.

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A minor, less obvious update is that you now can use your email to login and not just your username.

Standalone impulses

2020-02-02

Standalone impulses are here!

We figured that uploading impulse responses to our library was a hassle for all of you.

So while we are working on a new way to create those sweet IR’s we decided to add another section to the library:

Standalone impulse responses

These buggers do not require a connection to anything. The more you know the impulse you are adding the easier it will be for others to find it.

Simply select the file, give it a name and a nice description and you’re set.

 
To celebrate the launch of this new section we have added about 1200 of them!
Check them out!

User account launch

2019-07-14

We have just opened up for user registrations,!

To create a user account use the ‘Login’ button in the upper right corner.

As a logged in user you can upload your own impulse responses to our library.

If you have any questions – feel free to send us a message at Facebook or email

Note that this is a very early access and we are releasing new features as soon as they are ready

Checkout the video by Carl on how to register and upload you impulses below!

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How it works

The impulse response is the sound of the amplifier speaker. Every speaker has a particular sound quality which will drastically alter the result of any recording – no one speaker sounds alike! By capturing the frequencies of the impulse response on an amplifier speaker, and then transforming it into a simple .wav-file, you’re able to replicate the exact sound of that speaker digitally. These .wav-files are then made readily available on this site for you to dig into and start creating your next masterpiece.

all sounds must come from the speakers [translation] • Stereo.ru

Subwoofers in music systems have ceased to have any meaning for me personally. I don’t see much point in this. For home theaters, subwoofers are mandatory, I do not argue with that. As far as music is concerned, it is not often necessary to reproduce frequencies below 50 Hz. Most speakers with 5″ or larger woofers handle bass well in small to medium sized rooms. Of course, if you want to rock bass, or you have a big room, then you need bigger speakers, and a subwoofer can come in handy.

I thought about subwoofers in the context of music systems after reading the article “The case against subwoofers: forget about bass” (translated by Stereo.ru). This stuff reminded me of how I myself used to use subwoofers in my system. Of course, subs add bass, but the problem is to match the subwoofer with the main speakers. At best, you will have to fiddle for a couple of days with the settings and placement of the subwoofer. However, it is extremely rare to set everything up perfectly – this is a complex and ambiguous science.

It took me a while to realize that the subwoofer harmed the sound of the system to some extent by distorting the music. A perfectly integrated subwoofer is one that you can’t hear. All sounds must come from speakers. I started by lowering the subwoofer volume on my system (I lowered the volume more each time). I had a lot of different good speakers: Focal Mini Utopia, Magnepan 3.6, Zu Druid MK4, Dynaudio Special 25. All these acoustics coped with bass at 50 Hz and below. By the way, I also had first-class subs: REL Storm III and JL Audio E-Sub e110.

The subwoofer is the hardest to match with small speakers that need help in the 100 to 80 Hz range. This is really difficult. Personally, I think that a sub is not needed if the acoustics themselves cope with low frequencies. Better not spend money on a subwoofer. Here is a very interesting excerpt from the article I mentioned (it’s about excessive bass at concerts):

Subwoofers are needed where they are really needed: at dizzying music festivals, in nightclubs and in cars to scare others. Sunn O))) guitarist Stephen O’Malley (Stephen O’Malley) believes that sound pressure is real energy and sometimes this energy needs to be conveyed through music.

You’d be surprised, but O’Malley, being the king of the bass world, doesn’t use subwoofers to listen to music at home. “Not in my house. A properly tuned hi-fi system doesn’t need a separate subwoofer… Typically, all that bass has a negative impact on the rest of the sound spectrum,” says O’Malley.

I agree. The extra bass too much turns the music into an unbalanced boom. Someone likes it all, and they load more bass. Personally, I’m tired of subwoofers. Now I have Magnepan .7 and TAD ME-1 speakers that handle the bass quite well.

It seems to me that it’s time for all of us to calm down: we, of course, can “thump” bass on our ears further, but this is a bad idea. Forget the Bass: The Case Against Subwoofers, author Damon Krukowski, who incidentally was the drummer in the American band Galaxie 500, concluded: movies and games, but not for normal listening to music. My understanding of “normal” listening is based on my personal experience of interacting live with musical instruments (both acoustic and electric). There may have been big changes in the world of music.”

I agree with Krukowski here too, but in the end everyone should enjoy the sound they like.

Original: The case against subwoofers for music

how the new SberBoom smart speaker works and why / Sudo Null IT News

For our team, this is not the first experience in the design of audio devices – you are well aware of SberPortal, the winner of international awards for industrial design, and the SberBox Time media speaker, which we already told .

Looking ahead, let’s say that SberBoom is very different from them – first of all, the sound architecture. Therefore, in this post we will not talk about how we came up with the appearance. We will not tell you how the backlight of the case was made. We will not write about microphones and assistants. About the chips in the package, too, not today.

The first post focused on acoustics. Under the cut – everything about the sound architecture of SberBoom.

Both mono and stereo

Anyone who now undertakes to design a column will first have to answer the question – what type of audio system are we making?

We were tempted to go with the trends and get confused with stereo. But even at the start, they decided not to do this. UX research helped make the decision.

We studied the behavior of a potential smart speaker user. The obvious was confirmed – audio devices of this class listen “in passing”, randomly moving around the sound source. They clean up to the music, get ready for work, dance, play sports.

With this way of listening, the “musical” attention is defocused, so only a few can really appreciate the stereo sound. Plus, moving around the room, the listener is constantly at different distances from the right and left channels. This can unexpectedly affect the perception of tracks – the user will hear the composition not quite the way the author intended.

360° sound is equally audible from anywhere in the room, from any side of the speaker

The team made a conscious decision to go in the direction of 360° omnidirectional sound. In our opinion, it is better suited for smart speakers in typical usage scenarios and allows you to achieve the desired sound quality at a relatively affordable price of the device itself.

At the same time, the very idea of ​​stereo sound has not been abandoned – this is a useful option for those who listen to music thoughtfully and seriously. Therefore, SberBoom and SberBoom Mini support the ability to create a stereo pair. To do this, you need to merge two identical columns. Moreover, this is done in our case without wires, and you can control playback from any speaker in the pair.

In a stereo pair, one speaker plays the left channel, the other the right. Each channel sounds at 360°

What’s outside

When we were deciding which product design we would go with, there were two options in the shortlist – identical interiors, but completely different from each other. Both designs successfully passed intra-team selection and focus groups.

The first prototypes printed on a 3D printer

To choose from, we made prototypes with rough acoustic setups: we printed two prototypes on a 3D printer that differed in acoustic design architecture, and one with a radically different direction – experimental, which we later abandoned. We installed emitters in the prototypes and connected external amplifier boards.

Architecture A, left variant: one 4″ woofer and three 1.5″ fullranges for a smooth 360° user experience.
Architecture B, Right Option: One 4″ woofer and one 2″ reflector tweeter for a smooth 360° user experience
Architecture B: one 4″ woofer and three 1.5″ fullranges

The main difference between the experimental architecture (option B in the figure above) and the others is that the sound of the device is directed in one direction. This would mean a virtual rejection of the conclusions about the sound of 360 ° formed after UX research.

Plus, although it was a pretty powerful config, we heard in tests that a vertically oriented case sounded subjectively better than a horizontally oriented one – this was the user experience that we wanted to give our customers. Therefore, we continued to work with cabinets, as in prototypes A and B.

Benchmarks vs “brands”

We knew we wanted to get amazing 360° sound. To concretize this goal, examples were needed. The candidates for the reference sound for us were Apple HomePod, Sonos One, BOSE 500, BOSE 300, Bang & Olufsen Beosound 1 and other speakers.

This is how we tested one of the first SberBoom configs, architecture A – compared with industry monsters

To stay in the economy, we had to find a compromise between acoustic performance and the cost of components. So they approved the final standard and the final architecture of the column: about it just further.

What’s inside

In SberPortal, our last acoustic flagship, we used a full range driver to reproduce a wide range of frequencies and a passive radiator, also known as a passive radiator or PR, to increase the bass response of the audio system. SberBox Time also has broadband, already two. In SberBoom, everything is different.

As we wrote above, it was necessary to stay in the economy. Therefore, the development team proposed solution B. Architecture B implies the use of two drivers (excluding passive heatsinks) instead of four in solution A. Let us tell you in more detail why we chose this particular architecture.

Bottom driver: midrange/woofer

The woofer and reflector are heavy, which clearly affects the mechanical balance of the system. When placing the woofer at the top of the structure, there was a risk of failing Gravity tests: the device could swing when pressing the buttons, walk on the surface when playing music, etc.

Also, placing the woofer on top ran the risk of affecting the metrics of the VQE unit (voice quality enhancement): sandwiching the mic/LED board and button mechanics would potentially generate more distortion. There were two ways to get rid of this. The first is gluing the rattling parts with foam pads. This helps, but clearly affects the cost of the device. The second is to increase tolerances between mechanical parts. This does not affect the cost, but it affects the perception of the industrial design of the device. For the reasons described above, the team decided to place the bass driver at the bottom of the speaker.

Top driver: fullrange or tweeter?

Fullrange has a wider range than a tweeter, but needs more attention to get the best performance. The ideal use of broadband involves a closed chamber in which the unit is placed. The “broadband + closed chamber” configuration would affect both the cost and the design of the speaker. The cost of the device: the cost increases due to the mechanics of the closed chamber itself, plus there are additional costs for production – sealing, installation time, etc. Industrial design: the proportions of the device had to be changed. The column was stretched in height, and the filigree honed industrial design was transformed from a premium interior form into an unsightly torpedo. In order not to lose in design and not to increase the cost, we chose a self-sufficient tweeter with a focus on high frequencies and partial coverage of medium frequencies.

This is how we arrived at the final architecture – a tweeter with a reflector at the top and a woofer with a reflector and two passive radiators at the bottom. By the way, Bang & Olufsen do the same thing – they use two different drivers.

SberBoom in a sectionYou can get stuck – here is the whole filling of the column, to the screw

The team chose a configuration well-known on the market of sound devices and time-tested. Relatively simple. But the task of making this a truly productive acoustic device has become an engineering challenge.

As we agreed with the woofer

To achieve predictable quality, we ordered all acoustic components for SberBoom from a reliable, well-known manufacturer of acoustic solutions in the market, with which premium acoustic brands work.

The development of acoustic hardware actually took 4 stages of development and 3 test gates. As a result, we were able to increase the sensitivity of the woofer, equalize its amplitude-frequency characteristics and reduce the overall level of harmonic distortion. Here are the steps we have gone through.

Release 1

The report on the problems of the first acoustic release contained:

• Walking issue – when the speaker “walks” while playing bass tracks;

• Rub and Buzz problem – when unwanted noises appear;

• rattling problem;

• bad bass;

• tweeter sensitivity problem;

• problem with passing stress tests.

Release 2

Second release verification report included:

Release 3

The third release review report included:

Release 4

The fourth release was confirmed by the development teams — we managed to rid the hardware design of childhood illnesses. All further acoustic tuning focused on sound processing by equalizing.

Below we will describe in more detail how each of the described problems manifested itself and how we solved them.

Walking issue

In the frequency range 40-50 Hz, the wall of the passive radiator hit the wall of the acoustic chamber. Such an imbalance in the design caused not only a parasitic sound that affects the user experience when listening, but also the movement of the device itself when playing tracks at high volume. The way out was simple – to adjust the camera design. It was necessary to cut off the edge of the chamber wall, which was touched by the rubber of the radiator.

Release 1 and Release 2List of tracks that checked the problem Release 1 and Release 2
This is how we checked Walking issue

R&B (Rub and Buzz) problem

R&B is a typical problem of all acoustic devices, which has not bypassed our design either. Not to be confused with Rhythm & Blues, although the problem is most obvious in this category of music.

Rub and Buzz is the friction and buzz that the speaker generates, for example, when the chamber is not sealed enough. Previously, we used EVA (ethylene vinyl acetate) sealant for SberPortal. In the case of SberBoom, it did not fit, it was necessary to replace EVA with a denser PORON – a patented material that is a dense polyurethane foam. The reason the EVA didn’t fit was that a 4″ 2 ohm 50W woofer with a frequency range of 20 to 4000Hz (in SberBoom) pumped the camera more than a 30W fullrange with a range of 65-20000Hz (in SberPortal).

Sealant placements

We checked the solution – we looked at how THD (Total Harmonic Distortion, the coefficient of non-linear distortion of the audio system during sound) depends on the frequency range.

The red graph is the result of using a denser material

Why couldn’t PORON be used right away? This material is definitely more expensive. The goal of the SberDevices technical project team is to strive not only for high device performance results in all functional blocks. It is also important for us to strive for the optimal ratio of device cost and user experience.

Parasitic crackling problem

One of the prototypes during testing and testing

The design of the woofer itself was found to have a problem with the spider, the flexible part of the speaker cone suspension system that resonated at 120 Hz, drastically increasing the THD level. The spider design was redesigned in four stages. The main goal was to reach the nominal values ​​of the resonant frequency, which did not appear crackling – as when testing the first hand-assembled samples.

The speaker vendor’s design team needed to reshape the spider to reduce the resonant frequency parameter. The final decision was left to the design, increased in height from 1.74 mm to 2.07 mm, due to which 90.6 Hz dropped to 82.2 Hz.

Frequency graph. Red – before revision, green – after

Insufficient sensitivity of the tweeter

In the selected acoustic config, as you already know, a small number of units. And the ambitions are big – the team wanted to get the best sound on the smart speaker market. Therefore, attention to the quality and performance of each of the speakers was extremely high. Simultaneously with the woofer, the tweeter required experiments and improvements. We corrected the dull sound during playback and, as a result, a bad listening experience by working on the design and specifications of each of the drivers. In the case of the tweeter, they decided to rework (albeit slightly) the case of the tweeter itself in order to place a magnet of a larger diameter in it.

On the left – the yellow graph below, on the right – the green graph below The development teams began a series of experiments related to the adhesive layer of the woofer design. The requirements for the product included the ability of a smart speaker to work in the kitchen. This made us obligated to test all SberBoom hardware elements for high humidity behavior so that users can cook their favorite pasta while listening to music and talking to an assistant. And the glue failed us! If you cook, for example, jelly or pasta for 6 hours in a row, at high temperature and humidity, the construction of the woofer would literally melt.

“before” photo

Finally, we found another adhesive that can withstand such extreme stress.

Stationary – from the word “fixed”

One of the types of standard tests of a new acoustic device during and after debugging an acoustic hardware design is a Walking issue test or, in other words, a mobility test. After fixing bugs and adjusting the equalizer, taking into account the scenarios described in the brief from the product team, the development team needs to decompose the use cases into a test plan and conduct a series of tests on different surfaces – glass, plastic, wood, metal, etc. As part of the tests, it was necessary to make sure that the speaker stands confidently and sounds high quality on any horizontal surface, even when playing bass tracks.

Tests have shown that the walking issue effect appears again even with the previously corrected problem with the imbalance of passive radiators – SberBoom “walked”. The reason is that improvements in the equalizer improved the bass, which in turn began to rock the device. We could not refuse equalizing. Therefore, they solved the problem by changing the mechanical design of the rubber base of the column – they finalized this damper layer to compensate for low-frequency sound vibrations.

To better stabilize the device, the team went through several iterations with material selection. As a result, we chose the most suitable softness of silicone (similar to the SberPortal solution), worked out a series of DOE (design of experiments) together with engineers and designers to test engineering hypotheses. As a result, the number of legs on the base was increased from three to five.

A separate classic task when creating any audio device is to work out its mechanics in such a way as to reduce THD and resonance. The team consistently throughout all releases (mechanics, acoustics, electronics, equalizer software solutions) checked and localized all rattling mechanical elements – wires, buttons, etc.