$300 RSL Speedwoofer 10E Subwoofer Review

RSL 10" Subwoofer for $299 Shipped?!?

The audio market hasn’t been immune to the dramatically rising prices over the last few years, and unfortunately, this has priced a lot of people out of buying higher-performing products. Receivers, loudspeakers, and audio accessory prices have risen dramatically since the pandemic, and a dollar doesn’t go as far as it once did. So what can be done if you want a good sub but are cash-strapped? RSL Speakers might have done this market segment a BIG favor with their recently-released Speedwoofer 10E. The Speedwoofer 10E bears a lot of resemblance to their very popular Speedwoofer 10S MKII: same woofer appearance, same enclosure size, and same amplifier type. The most obvious difference is the pricing. The Speedwoofer 10E is priced at $299 (Shipped) as opposed to the $450 price of the 10S MKII, a 33% reduction in cost. The question then becomes: how much of the more expensive sub’s performance can be retained in a lower price point? And how does the Speedwoofer 10E fare against other $300 subs in the market? Those are some questions we will try to answer in our review of the RSL Speedwoofer 10E.

RSL Speedwoofer 10E Subwoofer Packing and Appearance

The Speedwoofer 10E arrived at my doorstep in a modestly-sized box and was surprisingly well-packed for such a low-cost sub. It was double-boxed and had edge and corner protectors inside the inner box. Four polyethylene foam blocks lined the top and bottom of the sub to protect against shocks. The sub was wrapped in a soft foam sack to protect against scuffs. The level of packing is more than sufficient to withstand the usual abuses of parcel shipping services.

Once unpacked, the Speedwoofer 10E stands as a rather innocuous subwoofer that doesn’t draw much attention to itself. It’s not large, and it doesn’t make any stylistic flourishes that are especially notable. Without the grille, it’s just a black box with a woofer installed. The edges are not rounded unless the grille is installed since only the grille has rounded edges. The finish is a textured vinyl which is very common with budget subs and speakers. The finish is not bad-looking, and it is fairly durable and is resistant to scuffs and fingerprints. The only real visual feature is the woofer itself, the surface of which is covered by a smooth, concave black-anodized aluminum dust cap. It’s a good-looking driver and looks similar to the cones in RSL’s other subs. There isn’t much else to say about the appearance of the 10E; it is a fairly plain-looking sub, not bad but certainly not fancy, and its low cost probably prohibited RSL from making any striking stylistic moves such as curved cabinetry or higher-end finishes.

RSL Speedwoofer 10E Subwoofer Design Analysis

In the broad strokes, the Speedwoofer 10E is a lot like the 10S but with features removed and certain build aspects taken down a notch for a lower manufacturing cost. But the overall design remains the same, and RSL’s most distinct design attribute is their “Compression Guide” tuning system. This unique feature lies in the cabinet’s internal construction; the interior space is divided into three different chambers where the backwave pressure from the rear of the cone can compress and expand in a manner that reduces resonances. It seems to borrow from transmission line theory, which can get quite complex. Within the sub, there is a solid diagonal piece that stretches from the lower front of the enclosure to the upper rear, so there are two larger compartments in the enclosure. The upper rear of the sub is open so that the backwave goes over it into the lower compartment. There is an opening in the front of the lower compartment that opens up to a slot port, which extends to the back of the sub. The larger chambers divided by the diagonal piece are filled with a thick batting material for damping internal waves.

As I have said in previous reviews of RSL subs that contain this system, I couldn’t say how efficacious the Compression Guide Technology really is versus traditional ported systems, but RSL’s other subs performed well, and, if nothing else, it does add a good deal of rigidity to the sidewalls of the cabinet. The MDF enclosure is already fairly well put together for its price range, with a 1” thick front baffle and ¾” thick sidewalls and braces, as well as corner braces to reinforce the edges. The cabinet construction and sidewall rigidity imparted by this design make the 10E a much more solid sub than ANY other in its segment.

The driver looks to be above average for this segment as well. It uses a Kevlar-reinforced paper cone with an anodized aluminum dust cap. It is attached to the basket using a beefy nitrile-butyl rubber surround and a poly-blended spider. The basket uses a stamped steel frame, but the frame has lots of bumped-out ridges which add to its overall stiffness. The motor uses a double-stack of magnets which add up to a 1 5/16” thickness and a 5 ½” diameter. Venting is done under the spider as well as through the pole piece.

The driver is powered by a 300-watt RMS amplifier that uses a class-D design. The amp panel controls are only the bare necessities with a volume knob, a low-pass filter knob that goes from 30Hz to 200Hz and bypass, and a variable phase knob. Connectivity is limited to a left/right pair of line-level inputs. The crossover filter uses a 12dB/octave slope. There is also an auto-power switch and an on/off switch. I do think the labeling of the auto-power switch is a bit convoluted. You can set the auto-power to “on” or “off,” and I think that most people will see that and assume that “off” powers down the amp, and “on” puts it in a standby mode. However, what “off’” really does is stop it from going into a standby state. I made the mistake of flipping the auto-power switch to “off” thinking it would no longer amplify signals, and I thought something was wrong after it continued to function and produce sound. After looking closer at the labeling, I realized my mistake, but I think that a lot of other users will make the same assumptions that I did, given its labeling.

The Speedwoofer 10E feet are fairly typical cylindrical rubber pieces that should do well at damping vibrations and not scratch any hard flooring. The grille is held in place by typical rubber grille guides. With the grille on, the front vertical edges of the sub have curved corners, so it might not cut or jab anyone unfortunate enough to brush against it. Without the grille, all the edges are hard 90-degree turns. Much like RSL’s other subs, if the user has kids or pets, it would probably be best to use this unit with the grille on, not just to protect the cone but to protect against injury from anyone running into a hard edge. Its matte black finish makes it a light sink, so users should take care not to place it near any commonly used walking path, because it could be hard to see in low-light conditions, and, given its height, household occupants could bump their shins against a hard ninety-degree edge, and that would surely sting.

RSL Speedwoofer 10E Subwoofer Listening Sessions

The best placement for a single sub in my room gives me a relatively flat response for an un-EQ’d single subwoofer, with a window of +/- 4 dB from 25 Hz to 100 Hz with no broad dips in important ranges. This location trades low-end room gain for a relatively flat response − a worthwhile trade for my tastes. The receiver used was a Marantz AV7705. The crossover was set to 80Hz. The speakers used were my Ellis 1802G custom bookshelf reference speakers.

As always, I will note here that since room acoustics have a huge effect on low frequencies, the way these subwoofers sound in my room at my listening position is not necessarily going to be the way they sound anywhere else for anyone else, so readers would do well to keep that in mind, and not just for this subwoofer in this review but for any subwoofer in any review.

Music Listening

I normally start to critically listen to subs using something centered around the pipe organ since it is one of the few acoustic instruments that can really take full advantage of a subwoofer’s range. Usually, the recordings I use are classical in nature, although occasionally they may be more contemporary compositions. Today’s album is very unusual in this respect, as these pieces use a pipe organ to emulate the type of loop-based compositions one would typically see in dance music. This is not to say that this music is danceable, but rather that it leads to a uniquely mesmeric effect that I quite enjoy. The album is “Nachthorn” by Maxime Danuc, played on the organ at the St. Antonius Church of Dusseldorf (Available at Bandcamp: Nachthorn). The bass doesn’t dig super deep on every track, but there are moments when those deeper registers require some low-frequency muscle to pull off.

After a gradual intro track, the second track infuses some energy into the proceedings, and trance-inducing rhythm is underpinned by a low-frequency stab. The bass here is given a strong footing by the 10E, yet it has a seamless blend with the speakers. The third track brings in a much thicker bassline, and the 10E managed to communicate the large scale of the pipe organ, exhibiting why it is sometimes called the “king of all instruments.” The subsequent track used bass softly in an almost samba-esque rhythm, and here the 10E was capable of a light touch by providing a low-frequency foundation without drawing attention to itself. Many of the tracks in this album are unusual in that the pipe organ bass is used in a rapid arpeggiation, and the 10E gave the pulsating rhythms a good sense of definition so that they didn’t get blurred by the reverberant decay of the church’s acoustics. The album reached into near-infrasonics with track 7, “Papillons,” and these ultra-deep notes were given a subterranean quality that surprised me from such a small budget sub. “Nachthorn” was a pleasure to listen to on the Speedwoofer 10E. Hardcore pipe organ enthusiasts might want something that will dig down to 16Hz without breaking a sweat to really nail those 32’ pipes − a feat that is likely beyond the 10E’s abilities. But I think most classical music lovers will be very pleased with the 10E’s general performance for this mighty instrument.

A new album from John Carpenter, Cody Carpenter, and Daniel Davies promises a fair amount of bass from both acoustic and synthetic instruments: “Lost Themes IV: Noir” was released in May of this year on the Sacred Bones label. While still known chiefly as a film director of classic horror movies, Carpenter’s music has become so influential in itself that it has nearly inspired an entire aesthetic movement. Much of the “retro-synthwave” music is merely amped-up Carpenter-style music. But why listen to imitators when the real thing is still producing quality music? “Lost Themes IV” serves up lots of low-frequency content to keep subs busy with heaping helpings of bass guitar, bass synths, and bass drums.

“Lost Themes IV” opens with a meaty bass guitar rhythm and overlays it with a deep kick drum, and the 10E delivered all of this low-frequency business with some real muscle. The second track, “Machine Fear,” is a bit unusual in that it uses the lower notes of piano for bass. But a full piano does actually hit fairly deep frequencies as the track demonstrates, and the 10E gave it a full-bodied sound that fully expressed the depths that the piano is capable of reaching. Track 5, “He Walks By Night,” is reminiscent of John Carpenter’s themes from his horror films from the ‘80s, except that it uses a lot more percussion than those scores did, and the percussion comprised deeply tuned electronic instruments that thumped nicely with the 10E sub. “Kiss the Blood Off My Fingers” (what a wonderfully evocative title) sounded like the theme to the greatest slasher movie never made, and the bass drums and electric guitar had a brawny growl, thanks to the 10E. “Lost Themes IV” is largely hard rock music with lots of electronics, and its extensive use of bass was reproduced with aplomb by the Speedwoofer 10E. I enjoyed listening to this album, but it did make me wish that Carpenter were still in the director’s chair as well as in the studio because the music reminded me of his classic films so much. 

Dark ambient music is a genre that can be relied upon to use deep bass, so I usually give some of those albums a spin for the subs I have under evaluation. For the Speedwoofer 10E, I selected an unusual dark ambient album titled “Acts of Light” by Hillary Woods, which I found on Qobuz. What is unusual about this album is that the sounds are largely acoustic, not created on synthesizers or by computer programs. Hillary Woods, a bassist for late-90s indie-rock band JJ27, returned to music in 2013 and has moved steadily from pop music to more minimalist styles. “Acts of Light” nearly completes this arc as the songs in this album are slow, austere dirges. Low frequencies come into play as prolonged bowing of the double bass and cello, synth drones, and field recordings. The bass here is multi-layered, highly textured, and in need of very linear low-frequency playback to get right.

The first track lays down a drone made up of overlapping bowed double basses, and the 10E could shore up the low end without giving away its existence as a part of the system. Of course, much of that integrated sound has to do with calibration, but the sub has to react predictably and competently in order to be properly calibrated. The second track uses a rapidly oscillating rumble that is given a guttural presence by the sub. The title track, “Acts of Light,” uses a gradual thumping sound to underlay a bowed string drone; the 10E does a lot of heavy lifting here and provides a solid bedrock for this bottom-heavy composition.  Much of the rest of the album’s bass is similar: pensive thrumming, uneasy drones, and a dark choral mist hovering above it all. Though it is not a large or expensive sub, the 10E lacked for nothing in the reproduction of this album, and I enjoyed my listening experience with it. This is miserable music in the best possible way; Hillary Woods is like the anti-Taylor Swift, and if you are looking for an antidote to the facile sunniness of top-40 pop music, “Acts of Light” may be just what the doctor ordered.

To see what the Speedwoofer 10E can do when stressed, I threw on Ternion Sound’s “Clutch” EP, which contains four tracks of some massive dubstep bass. The bass on this EP digs deep and plays loud, and it allows you to see how your subwoofer handles itself at its limits. We last saw Ternion Sound in our review of the HECO Aurora 30A, with their epic “Emergent Lifeforms” EP. Ternion Sound is composed of three dubstep artists known individually as Apparition, Johnny Foreplay, and Nostalgia. Through their Ternion Sound act, they have released banger after banger; a capable subwoofer will sing with this music at a high volume, but a poor subwoofer will scream in agony.

Opening with a sample of Andrew Ryan’s rants from the classic PC game “Bioshock” is an easy way to win me over, and giving me a thick wobbly bassline is a great way to top it off. The 10E supplied the bass with potent oomph that had a physical presence. Ternion Sound kicks it up a notch in the second track, “Trafalmadore,” with a more aggressive sound, and the bass was a pulsating churn that sounded like a giant diesel engine. The 10E again impressed with how much sound could be produced from such a modestly-sized enclosure. I decided to push it as hard as it could go, so I turned off the amp powering my speakers in order to protect them as well as my hearing, and then I cranked the volume up till the sub could not get any louder. Again, I was impressed by what it could belt out. At this highest output level, I could hear some buzzing from the enclosure, but the driver wasn’t rattling its screws off, so the sub was running into DSP limiting to save it from self-destruction. While its loudness wasn’t on the level of larger and more expensive subs I have dealt with, it did exceed expectations from what a $300 10” subwoofer could do. I think few users would actually run into its limits unless they were actively trying to. Electronic music lovers on a budget have a great choice in the 10E.

Movie Watching

One movie that looked like a good romp for a subwoofer was the 2022 actioner “The Grey Man” on Netflix. This big-budget movie stars Ryan Gosling as a contract killer for the CIA who uncovers some dirt on a high-ranking intelligence official during a job, and this creates a price on his own head among fellow assassins. I hadn’t seen it yet, but a movie like this should be filled with wanton violence and thus be a good workout for a subwoofer.

“The Grey Man” turned out to be a fun romp with some great action set pieces, many of which gave the 10E moments to shine. The first action scene with some serious deep bass occurred as a plane was disintegrating in flight during a fistfight. The shudder of a ruptured engine and the plane falling to pieces had the 10E filing my room with a palpable rumble. Later on, a terrific shoot-out and car chase in Prague leads to mass devastation, and the carnage was given a big-screen boom by the 10E. The finale at a castle involving RPGs and automatic grenade-launchers had the 10E thundering at each explosive discharge. Aside from the effects sounds, Henry Jackman’s score, a mixture of orchestral and electronic elements, gave the sub some robust low-frequency content to work with, and the 10E gave it a full and brawny sound. To be honest, I wasn’t expecting much from “The Grey Man,” but it turned out to be more exciting than I anticipated thanks to its inventive action scenes, and the Speedwoofer 10E was imperative in helping to bring those scenes to life. 

The surprise 2023 hit “Godzilla Minus One” has received a lot of accolades, including an Oscar win (a first for a Godzilla movie), so I was quite interested in seeing it, and now that it has arrived on Netflix, I decided it would be an opportune time with the Speedwoofer 10E in-house. A Godzilla movie would surely be a bass-fest and keep the sub busy, and it’s hard to imagine a film subject matter that could be a better workout for a subwoofer, aside from maybe a movie about non-stop earthquakes.

“Godzilla Minus One” was a terrific film and definitely lived up to the hype, and the 10E provided a vigorous low-frequency rumble for the scenes featuring Godzilla. The first attack had a relatively diminutive Godzilla (maybe 50 to 70 feet tall) attack a small military outpost on an island during World War II. This brief bout of carnage was infused with low-frequency energy by the 10E, which thundered away in my room. Godzilla’s attack on Ginza was where the movie really let loose mass destruction, and the pulverizing of buildings was rendered with an enthusiastic roar by the 10E. As with all the Godzilla movies where he is the sole monster, various plans are prepared to subdue the beast with mixed results, and the 10E relayed these battles with violent intensity. It should be said that while the 10E put up a very good showing, it wasn’t a match for the larger and more deeply-tuned subs around. But again, those are larger and cost quite a bit more money. RSL’s own Speedwoofer 12S probably could have lent Godzilla’s stomping sounds and energy blasts more low-end authority, but for $300, the 10E put out an exceptional sound. It isn’t going to suffice for a dedicated home theater system, but for a typical family room system, buyers will definitely be pleased by what it can do. If you haven't yet seen “Godzilla Minus One,” I would urge you to do so, since I can’t think of a better Godzilla movie since the original. Just make sure you watch it with a sound system with some potent bass reproduction. The 10E is quite good for its size and price.

RSL Speedwoofer 10E Subwoofer Measurements

Testing on the RSL Speedwoofer 10E was conducted with the microphone facing the woofer at a 1-meter distance with measurements scaled back to a 2-meter distance by subtracting 6dB. The temperature was recorded at 60F degrees with 90% humidity. The subwoofer’s gain was set to maximum; the phase was set to zero, and the low pass filters were set to bypass.

The above graph shows the measured frequency responses for the RSL Speedwoofer 10E subwoofer. Since this measurement was taken with the microphone facing the woofer, some port-produced output may not be fully represented here, so the 10E may extend a bit deeper than what is shown, though not by a lot. That being said, with this kind of response, users can expect a solid in-room response below 30Hz, though probably not 20Hz. Nonetheless, a sub-30Hz response is very good for a sub of this size and pricing. We also get an extended high-frequency response which is nice to see. The upper end of this response allows for higher crossover frequencies, which means the 10E can be mated with smaller speakers that may not have enough low-end extension to hit the standard 80Hz crossover frequency. At its pricing, it’s not unthinkable that it could be paired with smaller budget speakers that would require a higher crossover so that there is no gap in the response. Some budget subs don’t have much high-end extension above 100Hz, but the 10E is one that can be used with smaller loudspeakers.

The above CEA-2010 measurements are short-term bursts that show the subwoofer’s clean peak SPL before heavy distortion sets in. Our measurements have been referenced to 2-meter RMS, which is 9dB down from the standard requirement for the measurements to be shown at 1-meter peak. However most publicly available CEA-2010 measurements are shown at 2-meter RMS, so we followed that convention.

The Speedwoofer 10E puts out some very respectable numbers for its price class, especially for deep bass. Against much more expensive subs, yes, it doesn’t have monster deep bass output, but against other subs in the same price class, it is exceptional. And with 105dB+ for everything above 40Hz, it has a decent punch for musical frequencies. In my opinion, the 10E is making some very reasonable trade-offs with the kind of output exhibited here. With the enclosure size they decided on, they could have tuned it higher for more mid-bass punch but very little deep bass, or they could have tuned it lower for lower frequency extension but a much lighter punch in mid-bass frequencies. Instead, they went for a good compromise between the two. This sub will have some rumble for movie effects but also a good thump for kick drums. It achieves a nice balance for its size. This set of measurements earn the Speedwoofer 10E our Bassaholics “Medium” Room Rating, meaning it should be suitable for room sizes up to 3,000 cubic feet. To learn more about Audioholics’ Bassaholics Room ratings, please look at this article: Bassaholic Subwoofer Room Size rating Protocol. 

Testing for long-term output compression was done by first conducting a 20-second sweep tone where 50Hz hit 90 dB with the subwoofer 1 meter from the microphone (graph has been scaled to 2 meters for easy comparison with our other review measurements). We then conduct further 20-second sweeps by raising the gain by 5dB until no more output could be wrung out of the subwoofer. These tests show us the long-term continuous headroom that the subwoofer is capable of.

The Speedwoofer 10E does fine in this testing when its size and price are considered. It can put out a continuous 100dB at 30Hz and above. High drive level compression only shaves a bit off the low end, and the response doesn’t change that much ,even when pushed full-throttle. There is not much else to say except that, as with the basic frequency response measurement above, these measurements were taken with the woofer facing the microphone, and that does shortchange port output a bit, so there would be a bit more bass in low frequencies than what is reflected in this graph.

The above graph shows the corresponding total harmonic distortion to the long-term output graph. Essentially, it depicts how linear the subwoofer remains for the corresponding drive level seen in the long-term sweeps. The quantity being measured is how much of the subwoofer’s output is distortion, shown here as a percentage.

Again, we have a good set of measurements considering the cost of the Speedwoofer 10E. At the highest drive levels, it can be made to produce a fair level of distortion, but not a whole lot, and we have seen plenty more expensive subwoofers not keep as much composure when pushed to the limits. Keep in mind that the sharp rise in distortion that happens as frequencies drop nearer to 20Hz is where the sub dramatically loses output, so that stuff isn’t likely to significantly intrude on the sound. The region of interest for us is the stuff at 25Hz and above. At nominal levels of 90dB or lower, we can see distortion will be at 5% or less, likely a lot less at lower loudness levels. Above 100dB, distortion levels do kick up a bit, and the last few dB of output are accompanied by a notable rise centered at around 30Hz. However, in my testing, while the sub could be heard to audibly distort, it didn’t sound like it was self-destructing like some other budget subs I have tested. Strain on the driver was evident, but I was never worried it was on the verge of death, so the 10E does have some good limiters that keep it from self-harm on high signals. So as long as some sanity is used in operating the 10E, audible distortion will never be an issue, and even if it is pushed to the limits, users can have peace of mind that it won’t beat itself to death.

The above graphs depict measurements of the constituent harmonics from the long-term output sweeps and are what the total harmonic distortion measurements are composed of for the 2nd and 3rd harmonics. These individual harmonics can give us a clue as to what might be the cause of some quirk or non-linearity. We are only showing the 2nd and 3rd here because they more or less reflect the higher even-order and odd-order behaviors, although higher-order harmonics tend to be much farther down as a percentage of distortion compared to the second and third.

The above graphs reflect very typical driver behavior. At lower drive levels, we can see much of the harmonic distortion is composed of even-order products. This is probably due to inductance given the steady rate at which it increases with the drive level. As the driver reaches the limits of its linear excursion, odd-order products become prominent in lower frequencies. The motion of the moving mass is being restricted at both ends of its throw, and that is creating additional tones on top of the fundamental source signal. The good news is that, in music ranges above 40Hz, any distortion that the 10E can produce is even-order, which is a lot less noticeable than odd-order harmonics. This sub will have a very clean sound with music sources, even at high drive levels.

Group delay is the measurement of how much time it takes for individual frequency bands of an input signal to be produced by the speaker. It can indicate that some frequency components are developing slower than others or are taking longer to decay. It is generally thought that 1.5 sound cycles are needed for group delay to be audible at bass frequencies, although there is an argument that group delay should remain under 20ms to be completely unnoticeable, but that is likely meant for mid and upper bass frequencies.

The Speedwoofer 10E puts up a good showing in this measurement, and it generally keeps port-contributed output under 1 cycle until well under the port tuning frequency, where there is no more significant output. Mid-bass hangs under 10ms, and the 10E doesn’t exceed our minimum standard of audibility of 20ms until near 40Hz, so the sub WON'T have a laggy or delayed sound, especially in common music frequency bands. This is a great showing for such an affordable subwoofer.

Conclusion

Before bringing this review to a close, I will briefly go over the strengths and weaknesses of the product under evaluation, and, as always, I will start with the weaknesses. As a budget subwoofer, the Speedwoofer 10E’s pricing does shield it from some criticisms that some people could leverage. However, $300 is still a significant expenditure for most people, and I think it’s fair to expect that a subwoofer of that pricing won’t have any severe deficits. The good news is that, in my opinion, the 10E doesn’t have any serious shortcomings. I do have a couple of minor gripes. As was mentioned before, its height and matte black finish would make it a hazard to place near any commonly used walking paths, so users need to keep that in mind in finding placement for it. Rounding the lengthwise edges would be nice in case anyone does walk into it and hits their shins or knees, but I realize that would entail a price hike. This isn’t a major problem, and I think most users will be smart enough to not place it in a location that will make it a hazard. Another petty gripe I have is the labeling for the auto-power switch. At a glance, it looks like a regular power switch, but it really only activates the ability to go into standby mode if turned on. RSL might consider switching the labels from “on” and “off” to “enable standby” and “always on” respectively, or something else that would make its function a bit clearer.

Now let’s talk about the 10E’s strengths. Just as pricing is a consideration when assessing its weaknesses, so must it be considered with assessing its strengths. The Speedwoofer 10E is such a well-rounded package for the money that, overall, I think the balancing act that RSL has pulled off is its chief strength. Its performance is very good for the money, and, in fact, its burst test output gets very close to some of the $500 subs that we have reviewed. It doesn’t quite match its more powerful brother, the 10S MKII, but the 10S MKII has to be considered an overachiever at its pricing. Likewise, I don’t think users will find many $300 subs that can match the 10E’s overall performance (with a couple of exceptions) so it should be considered an overachiever as well. I think that most other subs near its pricing will have a higher port tuning frequency and so will not be as adept in deep bass. The 10E will give you solid bass down below 30Hz in-room. 

Along with its audio performance, its build quality is definitely a stand-out for its pricing, and I don’t think you can find any other subwoofer near its cost that is built as stoutly. It has lots of internal bracing and acoustic stuffing, a robust plate amplifier, and a solid 10” driver. As far as appearance goes, it is rather plain and doesn’t look bad. Its smaller size and matte finish mean that other household occupants aren’t as likely to notice it or be offended by its presence. Its smaller size also allows for easier multi-sub systems since it may have more placement opportunities. Multi-sub systems can return huge dividends in sound quality by shoring up nulls created by room modes (Audioholics has many good articles on this subject but here is a good primer: History of Multi-Sub and Sound Field management in Small Room Acoustics). A multi-sub Speedwoofer 10E system would not only add dynamic range, it could create a better in-room response so long as placement is chosen carefully.

Outside from the subwoofer itself, buyers also get RSL’s top-notch customer service. Their post-purchase support is renowned, and should buyers need help or have any technical problems, RSL is going to have their backs. A 2-year warranty on the amp is better than the norm for budget subs which normally have a 1-year warranty on electronics.

RSL 10E vs the Competition 

Among similarly priced subs, we most recently reviewed the Kanto sub8. However, it can’t quite be considered the same class of sub since it’s meant for desktop sound systems. That being said, if your desktop system could accommodate a Speedwoofer 10E, that would be pretty powerful bass for that application since the 10E has three times as much output in deep bass below 40Hz as the Kanto sub8. Another sub we reviewed at the same pricing was the Monoprice SW-15. It’s a considerably more powerful sub, but it’s far larger and is not as linear as the 10E. It’s a good sub for sheer output, but it’s not as well-rounded in overall performance. Something else in the same price class that we reviewed was the Dayton Audio SUB-1500. The SUB-1500 packs a heavier punch in mid-bass, but it’s larger and doesn’t dig as deep for low-frequency extension. Again, when we factor in all facets of design and performance, the Speedwoofer 10E finds a good balance in size, extension, and output for the pricing.

I am accustomed to much more expensive subwoofers, but I still enjoyed spending time with the Speedwoofer 10E, and in everyday use, I didn’t feel like I was missing much by not having something more powerful or higher-end in use. At such a modest cost, users cannot expect miracles, but I do think getting something that checks so many boxes without having any major shortcomings is something of a minor miracle in itself. It’s a great option at its price point, and I am glad to see that RSL has created something that works so well for those who want great sound but have a tight budget. The fact that RSL offers a no-risk, 30-day FREE trial period with shipping paid both ways makes it a no-brainer to try one out in your system.

The Score Card

The scoring below is based on each piece of equipment doing the duty it is designed for. The numbers are weighed heavily with respect to the individual cost of each unit, thus giving a rating roughly equal to:

Performance × Price Factor/Value = Rating

Audioholics.com note: The ratings indicated below are based on subjective listening and objective testing of the product in question. The rating scale is based on performance/value ratio. If you notice better performing products in future reviews that have lower numbers in certain areas, be aware that the value factor is most likely the culprit. Other Audioholics reviewers may rate products solely based on performance, and each reviewer has his/her own system for ratings.

Audioholics Rating Scale

• — Excellent
• — Very Good
• — Good
• — Fair
• — Poor

Metric	Rating
Bass Extension
Bass Accuracy
Build Quality
Fit and Finish
Ergonomics & Usability
Features
Dynamic Range
Performance
Value