Principles of Sound

Hi, John Hunter with REL. Listen, we get asked a fair amount, and this is just by normal folks who are not really understanding what subwoofers do. “Why does your speaker only make deep bass?” And there's another whole set of questions, which is, “Why don't you guys make speakers?”, which we’re not going to get into. We've specialized in just sub-bass systems for 35 years.  So here's the thing, let me back it up at explaining what speakers struggle with. Their biggest enemy is your room, rooms work really hard to make your speakers sound terrible. And one of the hardest parts to understand is that when you see the specification on your speaker, when you go to the spec sheet at the end of the sales brochure and it tells you “This speaker, (little six and a half inch, two way) will go down to 40 Hz”. It might, if it were dropped down a very deep elevator shaft. But the reality is the room itself is by just very nature of the geometry of the room. And the placement of those speakers within that room often is destructive, right? It won't let the speaker do what innately can do, it won't allow you to get to that 40 Hz, which is very deep bass by the way. What most people don't realize, how deep 40 is, what you need is a specialized device with a fair amount of power on its own, and a driver. The actual element that makes the sound and the cabinet all designed to work in the system to produce sound well below 40 Hz. Why is that important and why is my speaker not able to do it? Take it for somebody who's been studying room acoustics for the last, I don't know, 50 years of my life the proximity to sidewalls, the proximity of the floor, the proximity to the ceiling, all of those things contribute to cancel bass energy in almost every position in the room. And so having something that can actually extend and carry out real life, real output into the deep bass is what subwoofers do. That's the simple version of it. Even a speaker that in theory can do deep bass, can go into the upper 20s or something, almost none of them can do it in real rooms. There are a few very expensive speakers that can, but it is not something that you'll commonly be able to find a pair of speakers under $5,000, for example, that will reliably produce deep bass into the 20 to 30 Hz region in a real room. And that's what subwoofers do. What we're doing is we're producing huge amounts of energy, which gives us the energy to lift the output in that very narrow frequency below 40 Hz, down to whatever the room will allow us to produce. And that is a huge difference in the real world performance. Not to mention all the special effects of that are needed for movies. All the big bangs, the most impactful scenes all require a huge amount of power to do that. And subwoofers typically deliver more than your main system can. That helps you get that energy, that extension down low where all the fun happens.

<> The below text is a transcription of the video. Hey folks, John Hunter with REL here. Listen, we're gonna try a somewhat brave experiment. Stick with us. We are actually going to try and let people who are stuck at home, who have headphones, for example, don't have a huge audio file system, who are maybe thinking about getting into a very basic REL, for example, give them a sense of what it's like to hear this. We're gonna start with the REL and speakers together as an ensemble so you can hear what it should sound like. In the second cut, we're gonna take out the REL and you're gonna hear exactly the same recording levels on the microphones, everything identical. We'll cut at exactly the same point in time, and then we'll restore the REL for you so you'll have it in/out, no REL. Then in again. So that's the structure we're trying to do, and the purpose of this is really simple. There's a lot of folks that are curious about what does a REL sound like? They may not have the means to go to a dealer, maybe they're too far away to do it quickly and easily. So our hope is that this opens up a sense of what a REL can do for a system. To do this, we actually brought you into our development studio. This is where Justin and I develop all of the RELs that have come out since 2013 or so. It's produced a lot of great product and it's an important tool for us, a developmental tool. This is a great sounding room. We can get into a video some other time about how we built it, but this is a medium sized room. It's not a huge industrial studio. It more mimics what a traditional living room sounds like, but it's built in very specific ways that very few sound systems have ever had the privilege of working with. We're actually recording with mics on speakers. You can see these two that are on the speakers. And there's a large microphone down here that's on the REL. We worked for probably the two of us, a total probably 20 man hours going back and forth working to create the real sound. And we were listening and dialing in for the REL in the room as though we were just gonna be doing a live acoustic demo. All of these things are mixed at exactly the same levels. We don't monkey with the volume on the pre amplifier. The electronics are the same all the way through. Nothing gets changed at any point other than the take the REL in and out of circuit. This is a really straight recording. We're trying to let you hear what a nice sound sounding system in a really good room sounds like with and without the REL. That's it. We selected a really nicely recorded piece of acoustic jazz with an electric bass. This is not a melt your house down bass track. We did it on purpose. That is not difficult to do, you know, if you have a cut like that with and without a subwoofer, you should be ashamed if everybody in the world can't hear it. The purpose of this is for prospective REL customers to be able to hear music that is relatable. That's an open, articulate, delicate soundtrack that has some bass to it. And the purpose is not to melt the house down with bass on this cut. The purpose of this is to let you hear sort of natural music in a real acoustic in our room being picked up with real microphones. This is you know, sort of REL unplugged. This is really intended to be used with headphones. And I'll tell you straight up, the better quality the headphones are, the more you'll be able to hear exactly what a REL does. This is not intended to be listened to on your iPhone, your Android phone, transducers. The speakers in those things are completely incapable of resolving any of these details. You'll never hear the effect. I've tried it. Don't waste your time. I've done it with good headphones. It smacks you upside the head. You cannot not hear it. If you're into this stuff and you've been curious, you can import that into your own system. You can play it back through speakers, real speakers, not a little tiny compressed Bluetooth, you know. This is specifically not to be listened to by systems that have RELs in them. You'll probably skew to way too hot. So we have no intention of this being something really awesome and cool for a REL owner to experience in a new way. This is really for beginners to be able to get a chance to kind of get a crude idea of what it's like to have a REL. [Music] Listen, thank you so much for participating in this, for giving us a chance to try and share sort of the experience of having a REL in a system going through the whole phase where we take it out and then restoring it. We hope it was educational. We hope it was helpful. As we said earlier, this is just a precursor. If you like this, if you heard it, now you're curious, please go to a good REL dealer, ask them to do a similar demo with similar, really simply produced music. I just want to say this is a wonderful opportunity for us too. We're able to support some musicians that don't get a lot of airtime. There's so much talent out there. I'm sure they would love for you guys to go and be able to listen to more of their music. So thanks to those guys and we really hope that this was a fun educational experience.

<> The below text is a transcription of the video. What is DSP and why doesn't REL use it? It's really simple. DSP stands for digital signal processing. It's nothing more than a tool. First of all, it's not that we don't believe in DSP, we disagree with the way it's implemented in every case that we've run into it so far. Doesn't mean that those aren't really smart, hardworking engineers. It just means that we've not heard it be as good as a good analog filter. So why is that? I strongly suspect that what happens is that when you get into a normal subwoofer company, there are basically two things that suffuse the culture of that company. How loud does it play, and how low does it go? And so when you can take a tool like DSP and what DSP can do, for example it’s not a magical cine cure, but what it allows you to do is an engineer is look at the output. And if you believe that a perfectly flat output is the technical god that you're bowing down to, and that has a huge number of problems with it in real rooms, by the way, which is why it's a bad idea. But if you have a culture in your company that says, “Hey man, ours goes down to 19Hz and it's only whatever, 500 bucks or something”. What you can do is you can use DSP to pull down the energy output at middle and higher frequencies of the bass. That gives you more storage in your power supply. And it means that you can pump up the 20Hz range really loud. And if all you're trying to do is get that flat line of response and that's where it was a big problem, then there you go. And what it misses is all the human element. When you listen to deep voices, when you walk into a room and your footsteps echo around the room 'cause it's a big room, it's cavernous. All of those cues are really important to believability in, say, a film. You lose all that. What you get is when Tom Cruise, the cable snaps and he lands, you know, 25 feet down on a concrete floor in pitch darkness with weird little eyes looking at him, and it goes thump really loud. That's what you get. So you get one thump in a two and a half hour movie, and you lose all the believability of the other two hours and, you know, 29 minutes and 49 seconds. It's a terrible trade off. We don't believe in that. We believe that naturalness is what it's about. And that if you can actually help people get placed into the reality of the movie and forget about life for two hours, two and a half hours, that's really our job.

<> The below text is a transcription of the video. So, I've been asked, what’s the single greatest improvement you can make to a system? And I'm talking about everything from a decent, well-balanced beginner system right on up to the top. I'm going to tell you this straight up: there is nothing in our industry that will do more for your system than the appropriate REL added to an otherwise good system. It is not close. I say this because there are so many people who, after they've done five generations of cable improvements, after they've done three pre-amps, after they've been through five DACs, and after they’ve changed their streamers three times, finally get around to going, “Wow, adding a REL was the single biggest improvement I've ever made in my system.” And the sad thing is, it could have been that all along. So why would that be? I'll just touch on a couple of obvious points, but they’re not necessarily obvious to audiophiles, so it's worth saying. Now, the thing that is most affected by room and the thing that is most missing from every—even very good system is deep bass. When your bass falls off too quickly… the way I interpret myself is if you take the -6 dB point, if you take the point that we all agree feels and sounds like level is down 50%, when you have that happen at, say, 40 Hz instead of 20 Hz, it’s a big problem. You drop that thing from 40 to 20,000 cycles, and you have a line that looks like this: it is upward tilting, right? As soon as you can pull that down into the twenties—20 would be great, but honestly, 24, 25, 26 Hz is all the same in terms of its incredible impact on the balance of the system—all of a sudden, everything goes into balance. Suddenly, you're hearing full range. Suddenly, you're hearing deep, profound tonics that we hear in real life. We’re used to hearing these things; that's how life is experienced. And when you're chopping it off essentially an octave higher, you lose all of that, and you start to pitch shift. It's a very strange thing. Almost 100% of the high-end systems I've heard that don't have really high-quality subs underneath them are all high-frequency biased. Everything’s a little thin; everything's a little jangly. You start doing crazy things, like if you're an analog guy, you start fiddling with VTA on every record. Are you kidding me? That's insanity! And you're doing it because the system is so critical, because it’s all high-frequency dominant because of the absence of deep bass. So think of a subwoofer, a great sub like a REL, as the ability to actually balance your system for the first time. And you know what happens when you get it right? Your shoulders drop about an inch when you're listening, because you're no longer hearing stridency. You’re not hearing that sharp, edgy emphasis on the upper midrange, the high frequencies jangling. Everything balances out. We're fond of saying that RELs—I believe—are unique in this regard. Almost all good subs will give you that bottom octave or bottom octave and a half. But there’s something very different about how we do everything we do that gives you all ten octaves restored. It's got everything to do with our high-level inputs and all those things. But bottom line is, for whatever budget you’re on, the most important thing you could do to actually make a dramatic improvement—and it’s not a Band-Aid, it’s an actual improvement—is all the stuff that you think you're going to get from cables, or that you think you're going to get from a slightly better speaker. It's all there starting at the bottom. Build a house from the foundation up. Don’t sit there and change, you know, the color on your window shutters and think that you’re making a hugely better home. Start at the bottom, build a foundation right, and it will absolutely impact in a very positive way everything above it.

You just bought a new pair of XYZ speakers and the owner’s manual claims they produce excellent bass. Why do you think that is? Because the specs say their -6dB point is at 34Hz. Naturally, you might think, "Why do I need a subwoofer when my new speakers go really low?" But here’s the catch – while those numbers may look promising, real-world performance often tells a different story. Even with speakers that claim deep bass, adding a subwoofer can dramatically enhance your listening experience, no matter the size of your speakers. Curious why? Let’s dive in. While your speakers may measure well, the real question is: how much output do they deliver at that frequency in a real room? The answer may surprise you. In many cases, the output isn’t enough to be convincing. Why is that? Speaker manufacturers compete, and some may feel pressured to make their specs look as good as possible. That said, the best manufacturers are also the most honest, and their performance specs reflect that. Take Bowers & Wilkins, for example. They list both frequency range and frequency response for their popular 702 S3 model. They claim a frequency range of 28Hz to 33kHz (best-case scenario), but their frequency response is 46Hz to 28kHz ± 3dB—real-world performance before the room starts to degrade the deep bass. We applaud Bowers for being transparent. Your room may also be a culprit, as they’re often acoustically destructive when it comes to bass. Bass frequencies are affected far more than midrange or high frequencies because their wavelengths are so long. For example, that 34Hz bass note we mentioned earlier is 33 feet long (10 meters). That's long enough for the wavelength to fold back over on itself in all but the largest music rooms, causing cancellation at various points. And, as luck would have it, the point of maximum cancellation is often right where you’re sitting. This is where a REL subwoofer steps in with a distinct advantage. Unlike speakers, our subwoofers come with powerful amplifiers and precisely engineered crossovers that let us focus all that energy right where your speakers fall short. A subwoofer doesn't just play lower—it fills in the deep, visceral bass that most speakers can't handle. That’s the secret many people don’t understand. We operate independently of the speaker’s position, with an amplifier producing plenty of power, allowing us to position the subwoofer for optimal results and focus energy where it benefits the speakers without making them sound boomy. Another factor at play is how consumers interpret speaker specs. When you see "34Hz at -6dB," it means the manufacturer is telling you upfront that the speaker's output is half as strong as it is just one octave higher. An octave is a numerical doubling, so at 68Hz, your speaker will be playing 50% louder than at 34Hz. That's enough to make a noticeable difference. In reality, it could be even worse due to the bass cancellation mentioned earlier. Now, let’s consider that same speaker paired with a properly matched REL subwoofer. Take the B&W 702 S3 again, which, according to REL’s Subwoofer Finder, pairs well with our T/9x model for small and medium-sized rooms or a pair of T/9x subs for larger rooms. For truly large spaces, we recommend stepping up to the S/510. Either subwoofer will deliver powerful bass into the 20-30Hz region (T/9x) or even deeper with the S/510. For reference, 30Hz feels like a mild earthquake. To wrap things up, your REL subwoofer can be positioned to deliver maximum deep bass, thanks to its powerful built-in amplifier and variable crossover. This lets you set the crossover point so precisely that you won’t detect the handoff between the REL and your speakers, as you might in lesser subs, And it  will still produce deep, profound bass. By placing one or two RELs near a room boundary (where speakers can’t go) and leveraging our high-current amplifiers, we can concentrate energy into a narrow frequency range (26-52Hz in this case). This can result in a 10-12dB improvement in deep bass performance—more than twice the output of a typical real-world speaker. This is why almost ALL speakers, even large, well-designed floor-standing models, will benefit from a well-matched REL subwoofer. With a properly integrated REL subwoofer, your listening experience transforms. It’s not just about hearing the bass—it’s about feeling it. Whether it's the rumble of a movie soundtrack or the lowest notes of your favorite song, REL brings your audio system to life in ways that no standalone speaker can match. Thank you for reading our latest blog. We strive to provide content that’s both entertaining and educational. If you have questions or suggestions for future articles, reach out to us at contactus@rel.net. We value your input and will do our best to respond within a few days. With over 160 years of combined experience, we’re committed to making your audio experience exceptional. If you found value in this piece, please share it with friends who might benefit.