Dayton Audio SUB-1500 Subwoofer Review - Dual 15s for $500?!?

Audioholics recently reviewed a spate of $500 subwoofers (see our round-up here: The Best $500 Powered Subwoofers for 2023), and in the conclusion, we listed some potential alternatives to the featured subs of that article. The only alternative we listed there that we hadn’t reviewed was a pair of Dayton Audio SUB-1500s. Dayton Audio is a manufacturer of a wide variety of audio products from individual loudspeaker and electrical components to turnkey electronics and finished loudspeakers for every type of audio application. Based on the specs as well as our experience with past Dayton Audio products, we guessed that a pair of these budget subs would be a formidable option for those who are shopping in the $500 price range. Today, we set out to see for ourselves whether that guess was a good one in our review of a pair of Dayton Audio SUB-1500s. How do these stack up against the $500 subs that we have already taken an in-depth look at? How does one SUB-1500 perform, and how does that stack up into a set of duals? Are there qualitative shortcomings of a single budget sub that will hold a set of duals back from achieving the performance of a more expensive unit? Let’s now dig in to find out…

Packing and Appearance

The SUB-1500s arrived in double-boxed packing which is very unexpected at this low price point. Inside the boxes, there are two large polyethylene foam pieces sandwiching the top and bottom of the subs. The subs are wrapped in a plastic bag to protect them against moisture and scuffs. Overall, the packing is very good for the cost of these units. Since they are not very heavy, they should be adequately protected against normal shipping abuse.

 

Once unpacked, we are met with two nice but fairly conventional-looking subwoofers. They are not ugly but not gorgeous either, just standard subwoofer appearance. They use a matte black textured vinyl finish that does look a tad plasticky but it does not scuff easily nor leave fingerprints easily. There are grilles that hide the cones, but they do not cover the entire front baffle like most sub grilles. Without the grilles, we get a look at the woofers, which are treated paper cones with an inverted dustcap and a beefy half-roll surround. I think the subs look rather plain with the grilles on, but without the grilles, they have more character and look like they mean business. The overall shapes of the subs are cubes with just a bit over 19” of side lengths. One aspect that does a lot to soften their appearance is some rounding of the vertical edges; that is a nice touch and helps to make them less boxy looking. I like the simplicity of the design, and that will go a long way toward making them fit in a wide range of rooms.

Design Analysis

The SUB-1500 is not a terribly complex subwoofer, and it couldn’t be at its pricing. Dayton Audio specs this as a 15” subwoofer, and the driver really does measure 15” from the edge of the frame. Most subwoofer manufacturers spec their driver diameters like this, although some are a bit more conservative and spec their driver diameters at the mid-section of the surround. The cone looks to be made from treated paper and has an inverted polypropylene dustcap in the center. It attaches to the frame via a large 1 1/2” surround and a 6 ½” diameter Nomex spider. These suspension components are attached to a stamped steel frame. The motor is not monstrous and uses a 13/16” thick slug that is 5 ¾” in diameter. That doesn’t really tell us how much flux it sends through the gap, which is what matters the most. Since this is not a super high-excursion driver (indeed, Dayton Audio specs it at Xmax at 7.5mm), I would imagine that the magnetic strength is sufficient. The backplate is slightly bumped out, and venting is done through the pole piece.

One advantage of a driver like this is that it should have fairly low inductance. It has a 2 ¼” diameter voice coil and probably not a ton of copper, so it won’t generate as much of an induced counter-current that can diminish the upper-end bandwidth and cause an increase in even-order harmonic distortion components.

It is powered by a 150-watt RMS amplifier. While that might not seem like a lot compared to some of the multi-kilowatt sub amps we have seen around here, the driver’s sensitivity is rated at 91.9dB, so that should be plenty of power to make it thump. The controls are simple: there is a 0-180 degree phase switch, an auto-on/off power switch, a gain knob, and a 40Hz-140Hz crossover knob. Connectivity is comprised of a pair of RCA inputs and a pair of speaker-level inputs as well as a pair of speaker-level outputs. I am not sure how many people still use speaker-level connectivity on subwoofers, and I feel like Dayton Audio could have jettisoned that feature to save on manufacturing costs without any loss of sales.

  

The SUB-1500 uses an MDF enclosure with a bottom-mounted port. The port has a 7 1/4” length and 3” diameter and is flared on both ends. The feet are some tall plastic cones that would certainly give the port enough clearance to move air. The front baffle is 1 ½” thick with additional thickness for the driver mounting, and the side panels are ¾” thick. Bracing is just two corner braces at each internal edge. There is some acoustic stuffing lining the side walls but not a lot.

There is opportunity here for some significant improvement for owners who are willing to modify their sub and void the warranty. It would be easy and cheap to add some cross-bracing and a lot more acoustic stuffing. The cabinet can be made a lot stronger by just adding a few rods at the midsections of the panels. And adding masses of acoustic stuffing can have the effect of making the enclosure act larger through isothermal absorption. This is when the fibrous materials of the acoustic stuffing act like a heatsink and absorb the acoustic energy thereby increasing the compressibility of the air inside the enclosure. The stock form of the subwoofer is probably adequate, and I am not sure how much these structural improvements would bring, but they would not take much time, effort, or money to do.

The SUB-1500 is not the heaviest-duty build we have ever seen and is a fairly basic design, but when its pricing is considered, it looks like it could be a serious bargain. I think the key to its success is driver sensitivity and behavior as well as enclosure inertness. If the driver is truly 91.9dB sensitive as the specs state, then this sub could really put out a lot of bang for the buck. The output must be controlled too; it doesn’t matter if the sub has a lot of output if it only occurs in a very narrow frequency range. There is also a risk of the enclosure panels having audible vibrations that could infringe upon the sound, but it’s hard to say how much of a factor that is without testing and, most importantly, listening.

The Advantages of Two Subs Versus One

So why get two subwoofers rather than just one? The main answer to that question has to do with how room acoustics affect low-frequency sound waves. Audioholics has many articles that deal with this issue such as Early Reflections and Bass for Small Room Acoustics, Listening Room Acoustics: Room Modes and Standing Bass, and History of Multi-Sub and Sound Field Management for Small Room Acoustics. For those not inclined to pour over these somewhat technical articles, the short version is that the wavelengths of low-frequency soundwaves are much larger than normal domestic room dimensions, and to complete the wave cycle, the sound waves double back into the room. When the sound waves overlap on themselves, they can cause large peaks and cancellations in the room response, so some bass frequencies will be very loud and others will be very weak. A good way to hear this for yourself is to walk around your room while playing a pink noise tone on your subwoofer and notice the changing tonality from different areas of the room. One of the best tools we have to fight this effect, at least for subwoofer-band frequencies, is the use of a multiple subwoofer system to even out these peaks and dips in the response by averaging out the room modes per sound source. Let’s take a quick look at how that can work by using the two SUB-1500s in my own room:

 

The above graph shows the individual responses of the SUB-1500s in my room (the green and blue curves) and then the response of both subs measured simultaneously (the gold curve). The individual responses are what happens when I place the subs in the front left and right corners of my room. As we can see, the individual responses are rather erratic with the green curve generating a peak at 49Hz and a null at 62Hz and the blue curve creating a massive null at 46Hz followed by a massive peak at 53Hz. On their own, these peaks and dips can be audible. The peaks can be tamed with equalization, but the nulls cannot, but we can address the nulls with a multiple subwoofer solution.

The gold curve shows how both subs can average out the response for a relatively flat curve before any equalization. It still shows a peak at 54Hz followed by a dip at 62Hz, but these are now relatively minor deviations from the baseline response with about 3dB magnitudes. Equalization can flatten that response out even further, and since there are two subs in play, the equalization will be more consistent and predictable. Multiple subwoofer systems also make the response more consistent across seating positions over the room, and since equalization doesn’t need to change as much, its effects will also be more consistent across different listening positions over the room as well. This isn’t just a few abstract plots on a graph; this constitutes an audible improvement as well. This is why we at Audioholics always advise a multi-sub setup wherever possible.

Another advantage of multiple subs is that they can defeat the localization that a single sub can sometimes have. Many readers may have had the experience of listening to a sound system with a subwoofer, and the subwoofer’s sound made it obvious where its location is. There can be a few reasons for this, and using a lower crossover frequency may not always be the solution to this problem. By anchoring all of the lower bass to one location, a localized subwoofer can screw up the soundstage by tilting it toward the subwoofer. Using multiple subs can rectify this by counterbalancing the source of low-frequency sound thereby creating an even and uniform soundstage.

Listening Sessions

The receiver used was a Marantz AV7705. The crossover was set to 80Hz. The speakers used were some PSB Synchrony B600 bookshelf speakers powered by a Monoprice Monolith 5x200-watt amplifier. The SUB-1500 subwoofers were set up to yield a reasonably flat response without equalization (see above graph). 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

For an album of acoustic music that dips into subwoofer-band frequencies, I selected a new release titled “As We Speak,” a collaboration of Bela Fleck, Edgar Meyer, Rakesh Chaurasia, and Zakir Hussain. Each of these gentlemen is a master of their respective instruments: Fleck for the banjo, Chaurasia for the bansuri flute, Meyer for the upright bass, and Hussain for the tabla. While the banjo and bansuri flute does not really dig into deep bass, the upright bass definitely does and so does the tabla. Meyer and Hussain’s play on this album makes it a terrific demonstration of a sound system’s ability to reproduce low-frequency pitch and texture. I streamed this recording from Qobuz in a 24-bit/96kHz resolution.

The upright bass playing was a mixture of plucking and bowing. Some tracks, like “Rickety Karma,” were mostly plucked bass playing, and here we get a good look at the SUB-1500’s ability to deal with transients. I didn’t notice any specific lagginess or overhang here. The tabla shared much of the low-frequency content on this album too, but since it has an unusual attack that doesn’t peak right away, it wasn’t as easy to hear any lag if there was any. However, through the SUB-1500, I could discern the different pitches created by the baya bass drum of the two tablas drums. Likewise, the pitch definition of the upright bass was good as well. A good level of texture of the bowed playing was evident as well, and this could be heard clearly at the start of track 8, “Pashto.” It’s hard to say how much of this texture was from the subs or the speakers, but at least we can say that the sub wasn’t getting in the way by smearing the sound. The SUB-1500s had enough extension that I didn’t sense any missing low end at all from this music, not that I would have expected this kind of music to have extremely deep bass. I didn’t have any complaints about the SUB-1500 for the reproduction of the music of “As We Speak,” pretty impressive for subs that only cost $260 each!

  

As always, I bring a pipe organ recording into my evaluation of a subwoofer since it is one of the only instruments that can bring true power into the lowest octave of human hearing. Toward this end, I selected “Bach Organ Works, Vol. 1.” There are a lot of pipe organ albums featuring the music of Bach, but what makes this one special is that it is performed on a newly built organ that was made specifically for the compositions of Bach. The Contius Organ in St. Micheal’s Church in Leuven, Belgium was designed to recreate the organs of Heinrich Andreas Contius, an 18th-century organ builder whose designs were lauded by and frequently played on by Bach. However, none of Contius’ organs have survived over the centuries. A huge amount of research and effort was conducted in an effort to replicate the design and sound of Contius’ organs, and this album demonstrates the results; an organ made to sound the same as when Bach had performed on them.

While there are deep frequencies on this album, the organ music here isn’t blaring with gut-wrenching bass, and the SUB-1500s managed to make the bass a presence without overdoing it or under-doing it. The Contius Organ is old-fashioned (quite literally) and doesn’t have huge, earth-shaking 64’ pipes, but it does have some low-frequency muscle that must have been pretty awe-inspiring back in the 18th century and still sounds terrific. The SUB-1500s captured the bass of this instrument nicely and had a smooth blend with the speakers. As Bach compositions, the notation could be quite complex, even in the lower registers, and I couldn’t be sure how much of it was the speakers and how much the subs were doing, so I turned off the speaker amp to get a sense of the subs’ load. It was interesting to hear what they were doing and what they weren't doing. Almost all of the overtones were entirely absent, yet there were fundamentals and subtle subharmonics that were unexpected and not obvious when the whole spectrum was being reproduced. Again, the SUB-1500s had zero problems with pitch definition. While the low-frequency extension of the SUB-1500s seemed to be sufficient for this album, in-room sine-wave sweeps indicated that these subs were losing strength below 30Hz, so pipe organ aficionados should keep that in mind if considering these. They don’t quite make the stretch to the massive 16Hz notes of the larger pipe organs and probably won’t do justice to that lowest octave. However, the SUB-1500 does well for typical organs (or even atypical ones like the Contius) that don’t have gigantic pipes.

One neoclassical album that I found on Qobuz that dwells in deep bass is Alex Mason’s 2018 release “The Exorcist.” Much like the title signifies, this album sounds like the score for a horror film. It is mostly created with orchestral instruments but mixes in some electronic atmospherics, and it all adds up to a dark and foreboding sound. Mason (a Russian whose real name is closer to Alexey Maslov) mixes gothic elements with more contemporary composition for an elaborate and nerve-racking sound. He paints a vivid picture with music alone and conjures the drama and emotions from horror movies without the need for imagery or a standard narrative.

Much of the bass on this album comes from the traditional orchestral instruments that produce low frequencies such as bass violin, tuba, piano, and kettle drums, and the SUB-1500s captured the sound of them all. With so many bass-producing elements, the sub could be kept quite busy, but the instruments were all kept at a simmer for a sustained tension, and the bass was rarely pushed to the limits. “Reunion is a great example of low-key bass, where the stringed section seethes threateningly but never reaches a boil, and the SUB-1500s were able to render their understated menace with a good resolution. Some tracks used low-frequency synths for atmosphere, such as “Cold Contact,” which has a subtle rumble beneath a primeval percussive sound, and the minutiae of these sounds were not lost on the SUB-1500s either.

I do think there might have been some very deep bass in this album that the SUB-1500s weren’t quite catching, and they can’t quite match the subterranean feel of subs that have more power in the lowest octave. This would be skirting infrasonic bass, and there just isn’t much gas in the tank for these subs at that point- not that I would expect as much, given the specs and pricing of the SUB-1500s. There is no surprise that these can’t match the deep bass potency of larger and more expensive subs, and I would liken their extension to that of a sizable tower speaker. Most tower speakers are tuned from 30Hz to 40Hz, which is enough extension to cover almost all acoustic music and the majority of synthetically generated music. They sound full, as do these subwoofers, but for those of us who frequently listen to music extremes, as I do for these subwoofer reviews, there is a subsonic element that heightens the realism that is missing. I don’t want to overstate the importance of this near-infrasonic range, and by far, the most important frequency bands lay above 30Hz which the SUB-1500s have no trouble with. These are not miracle workers in deep bass, but they are very competent subwoofers.

    

For something to see what the SUB-1500s can do when pushed hard, I selected “Black Heart Communion” by Shades. We have seen Shades in Audioholics’ subwoofer reviews before with his brutal and brilliant 2018 dubstep album “In Praise of Darkness,” and I decided to explore his other releases. “Black Heart Communion” is a 2019 EP with some of the dankest bass ever recorded. It digs low and hits hard, and it beautifully shows Shades’ talent for low-frequency sound design. At a high enough level, the heavy-duty bass here will be sure to stress any subwoofer. Some subwoofers would crumble with this kind of content but others thrive, so I set out to see which camp the SUB-1500s fall in.

The use of heavy bass gets off to an early start at the beginning of track 1 with a massive reverberating bell, and the SUB-1500s give it an epic feel. Track 2 kicks it up a notch when the bass drops and it turns into one of the fattest basslines in electronic music. It sounded glorious on the SUB-1500s, truly immense. Subsequent tracks matched the huge sound of track 2. In fact, on track 4, the title track “Black Heart Communion,” I heard some clacking sound that I thought was one of the subs, seeing as how they do not have digital signal processing to set hard limits on the power that can be sent to the driver. After some investigation, it turns out to be the woofer for the PSB Synchrony B600, so the SUB-1500s turned out to have a wider dynamic range than these $2,800/pair bookshelf speakers. And that is not a criticism against the B600s but rather praise for the SUB-1500s, because I was not sending the speakers a ‘common sense’ signal; I was slamming them with 200 watts of power at loudness levels no sane person would endure. The SUB-1500s had a real tactile punch, and they really shined with this music at these volume levels. Basslines buzzed my seat and kick drums thumped my chest. Much more expensive subs are not able to achieve this sound. While I did reach the limit of the subs’ dynamic range here, it roughly coincided with my personal limits as well, and it was truly loud. The SUB-1500s killed it in electronic bass music, and if that is the kind of content you enjoy, and you have around a $500 budget, I really cannot think of a better choice after hearing what they did on “Black Heart Communion.”

Movie Watching

A movie I had not yet seen but which promised deep bass was the 2011 underwater thriller “Sanctum.” This movie is about a team of divers on an expedition to explore an underwater cave network. When a tropical storm forces them to take refuge in the cave system and cuts off their entrance route, they must survive the crisis and find another way out of the cave labyrinth. A major storm plus a water-bound setting means that this big-budget movie (produced by James Cameron, no less) should have tons of content to get a subwoofer’s cone moving. 

“Sanctum” delivered what it advertised as a tense fight for survival in an underwater cave network, and the SUB-1500 subwoofer pair helped to make this adventure more realistic and intense. The first moments of intense bass hit when the cave started to flood with the onset of a typhoon. Torrents of water gushed through the tunnels, and the crashing flood waters roared with menace on the subs. The rumble of impromptu waterfalls through the cave network was given a tactile dimension with the SUB-1500s. The crisis forces our main characters to escape through underwater tunnels, and the burbling and gurgling of the characters’ struggles when submerged were violently relayed through the subs. David Hirshfelder’s orchestral score added to the drama as well as the LFE load since it was replete with kettle drums and low-pitched brass. Again, there was probably some very deep bass left out, but I never heard the subs strain attempting to reproduce frequencies below their comfort zone. While “Sanctum” isn’t vying for Oscars as a rich human drama, I appreciated how straightforward and uncomplicated it was, and I also appreciated having a potent subwoofer system on hand to give it a more visceral feel.   

  

Another movie that looked to have a lot of fun LFE is the newer 2022 release “Kids vs. Aliens.” This horror-comedy is directed by Jason Eisener who made the great faux-exploitation “Hobo with a Shotgun” as well as the wonderful YouTube splatter comedy short “Treevenge.” “Kids vs. Aliens” is about two feuding siblings who throw a major house party, but their party gets crashed by some hostile aliens. Eisener has always pushed the boundaries of bad taste and blood-letting but has done so with a sense of fun and creativity. I had not yet seen “Kids vs. Aliens,” but I suspected that it would be a lot of fun, especially with a capable sound system on tap.

“Kids vs. Aliens” was just as nuts as I expected, and the SUB-1500s helped it to be the roller-coaster that was doubtlessly intended. The arrival of the aliens was announced by a deeply pitched horn, a parody of the 2005 “War of the Worlds” pods rising scene, and my seat shuddered from being pummeled by sound waves. Our main characters are captured and taken into the alien spaceship, and the deep hum of the craft and the guttural growls of the aliens were given a corporeal aspect thanks to the enthusiastic playback by the subs. Action scenes mostly consist of humans running away from aliens, so there wasn’t much bass, at least until the ‘grand finale.’ Much of the low-frequency content was provided by the music score by Andrew Gordon MacPherson who used 80s-inspired synthwave for scenes focused on the kids and orchestral music for scenes focused on the aliens. The SUB-1500s gave bass for both a meaty foundation, and the synth bassline and electronic percussion really shined with the subs. This highly vulgar yet goofy movie was a lot of fun, and the dual SUB-1500 was a great match for it.

Dual Dayton Audio SUB-1500 Subwoofer Measurements & Conclusion

 

Testing on the Dayton Audio SUB-1500 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 55F degrees with 55% humidity. The subwoofer’s gain was set to maximum, phase was set to zero, and the low pass filters were set to the maximum frequency of 140Hz.

 

The above graph shows the measured frequency response for the SUB-1500 subwoofer. Right away, we can see that this sub isn’t really geared for deep bass below the mid-30Hz range. In-room, users can expect a usable response down to 30Hz. My room gets relatively little low-frequency gain, and I still managed a decent response down to 30Hz. The flattest bandwidth occurs from about 40Hz to just over 100Hz, but I think users would be able to get usable output all the way up to 160Hz if they wanted to use such a high crossover frequency. As has been said before, the range of this sub will suffice for almost all acoustic music and most non-acoustic music. It will capture most of the bass in modern movie soundtracks as well, but not all of it. However, given the cost of the SUB-1500, I don’t know any similarly priced subwoofer that could dig any lower. If you want deeper bass, you will have to up your budget significantly.

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.

While I don’t have much to compare the SUB-1500 with at its low price point, I think it puts out some respectable numbers here. Compared to the subwoofers that we reviewed at around the $500 price point, it gets outpaced at 40Hz and below but starts to close the gap at 50Hz. At 63Hz and above, it largely matches the performance of those $500 subwoofers.

One interesting aspect to note is the recorded distortion; at 40Hz and above, it is mostly limited by the amp instead of distortion. While it hit the distortion thresholds at 80Hz and 100Hz, it wasn’t able to go much past that point. It could be pushed to produce distortion, but it wasn’t nearly as bad as I was expecting from a $260 subwoofer. In fact, the bass it did produce was surprisingly clean, and it was pretty reluctant to make flagrantly bad noises. To be sure, it wasn’t as well-controlled as subs that we have reviewed that were multiple thousands of dollars, but it was far better than I would have anticipated given the build and pricing.

This measurement set earns the SUB-1500 our Bassaholics ‘Small’ Room Rating, and it is held back by its performance at 25Hz. By our protocol, that technically means it should only be sufficient for up to a 1,500 cubic foot area. However, I would note that I do feel it could handle a larger area if you aren’t all that concerned about bass under 30Hz. For bass at 40Hz and above, it is much more capable and could handle a larger room. For more information on how our room ratings are determined, read our article: ‘Bassaholic Room Size Rating Protocol.’

We are reviewing the SUB-1500 as a dual subwoofer set, so what happens with two of them? The process to determine that is easy; we just double the output by adding 6dB. And when we do that, we get the below table:

Those are some pretty big numbers for a $520 subwoofer system, and it explains why it was so potent in the electronic music that I cranked hard on it. Comparing these numbers to the $500 subs that we reviewed, it has now mostly caught up with them down to 25Hz, and at 50Hz and above, it makes major gains against them. At 63Hz and above, it largely doubles their output. A dual SUB-1500 subwoofer system hits very hard in mid-bass and matches the mid-bass output we have seen from far more expensive subwoofers. It’s also worth mentioning how efficiently they are generating this level of sound. All of this output is coming from two 150-watt amplifiers. Many other subs that can hit these levels need a lot more power than what is being supplied by these amps to accomplish this.

A dual SUB-1500 system would merit a Bassaholics ‘Medium’ Room Rating, but again, it is held back by the 25Hz criteria of or protocol, and if you are looking at 30Hz and above, it could handle a significantly larger room. However, we should add one important caveat to the above numbers: a full 6dB gain going from a single to dual subs can only be had if you place them very close to each other, but this is not what we normally recommend for a multiple subwoofer system. Doing so can not address the dips and nulls caused by room acoustics, and it negates this major advantage of a multi-sub system. It maximizes output at the expense of sound quality. We recommend spacing the subs apart in a manner that best addresses low-frequency nulls formed by the room’s acoustics. In such a configuration, with the subs properly set up, you should still see a net +3-4dB increase in output from dual Sub-1500s compared to just having one in your system.

 

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 SUB-1500’s story for this graph parallels our burst test measurements: lots of mid-bass and progressively loses steam below 50Hz. Relative to our $500 subs, it matches their 50Hz output but gets surpassed below that range. If one were to add 6dB, we would have the total output of two SUB-1500s in which case it would match the deep bass output of the $500 subwoofer category and blow way past any of them in mid-bass.

 

The above graphs show the corresponding total harmonic distortion to the long-term output graphs. Essentially, they depict 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 and is shown here as a percentage. The SUB-1500 does surprisingly well considering its cost and construction. At nominal levels, it stays well below 10% THD down to 25Hz, and from 40Hz and above, it hovers around 1% THD. This is pretty fabulous performance for something that only costs $260/ea. Push it harder and distortion does creep up, but even then, it is reluctant to surpass 10% THD above 40Hz, even at maximum drive levels. It isn’t comfortable below 25Hz at any drive level, but the good news is that it doesn’t produce much output at all, so there isn’t much audible distortion to be had if you send it a high-level signal for deep bass. If you try to reproduce deep bass below 30Hz on this sub, it won’t complain very much but it won’t try very hard either, but if you throttle this sub at 40Hz and above, not only will it give it some real muscle, it doesn’t lose much self-control in doing so.

 

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 further down as a percentage of distortion compared to the second and third.

Odd-order distortion for the SUB-1500 doesn’t really crop up until the final 5dB or so of its performance envelope (the rise in distortion below 25Hz at lower drive levels is likely environmental noise in both of these and not actually an artifact of the sub itself). Even-order harmonics rise at a steadier level with an increase in amplitude and are more consistent across the frequency spectrum, and I would guess that is from some induction. It is not a lot, even at the highest drive levels, and I wouldn’t guess it to be audible. Even-order harmonics tend to be more difficult to discern, especially in music, since it usually comes with a natural harmonic of whatever instrument is producing the fundamental and is therefore much more easily masked. 

 

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 SUB-1500 does well enough in this measurement but not perfectly, although perfection shouldn’t be expected in this price range. At 50Hz and above, the group delay is excellent, but 40Hz does manage to exceed the 1-cycle threshold. At some points, I characterized the SUB-1500 to have a ‘tower speaker sound,’ and this may be partially responsible. Many tower speakers would share some of these traits since they have a similar tuning frequency. While they can have some output below their port tuning frequency, they lose definition, and I think the same is partially true for the SUB-1500. While it has some lower bass output, it doesn’t sound as sharp in that range as subs with lower tuning frequencies. I do think it is possible that this slight amount of lag around 40Hz gave it a really massive sound for electronic bass music. A lot of electronic bass music has bass lines and kick drums with fundamentals right in that area, and adding a touch of delay could have the effect of making them sound ‘big’ but without sounding sluggish. Whatever the cause, I really loved the sound that this subwoofer lent to that style of music. There is some sub-30Hz output, so there will still be some oomph for explosions and effects sounds, and thankfully effects sounds like rumbling don’t usually need pinpoint accuracy to sound fine. But as we have seen before, this sub is happiest at 40Hz and above.

Conclusion

Before bringing this review to a close, I will briefly go over the strengths and weaknesses of the product under review, and, as usual, I will start with the weaknesses. However, it’s a bit challenging to complain about the SUB-1500 when it is priced so low. At $260, expectations must be kept in check. I could complain that the build quality is rudimentary, but it isn’t bad for the cost and gets the job done for this very low price.

I could criticize it for not digging tremendously low in frequency, and I could also ding it for not having razor-sharp bass in the lowest octave. Dayton Audio might have been able to gain lower frequency extension by using a different design, but that would have necessitated a pretty stiff exchange of dynamic range, so the sub wouldn’t have anywhere near the punch that it does. This is the trade-off that Dayton Audio decided on, and I would say they chose wisely. Very deep bass tones are more difficult to perceive for the same loudness level as higher frequencies, so unless they can be produced with real dynamic range- a task well outside of any $260 subwoofer- it isn’t really worth chasing as a design target. However, it probably isn’t worth buying these for the purposes of adding extension to a system using tower speakers, since these won’t dig much deeper than most towers.

One might complain about the lack of features and frills. The feature set of the SUB-1500 is nearly the bare minimum (except for the curious inclusion of speaker-level connectivity), but every single extra part that is added on would entail a significant hike in the percentage of the cost. This is a budget subwoofer and has cut out all the superfluous niceties accordingly.

So, in summing up its weaknesses, the SUB-1500’s very low pricing shields it from many common criticisms- but not all. We have to ask what it does well, because if it is not competent at producing bass frequencies at all then it wouldn’t be worth buying at any price. Here I am glad to report it is very competent at reproducing bass frequencies. Yes, it falters below 30Hz, but at 40Hz and above, it is quite impressive. On its own, it can match the mid-bass output of subs that are twice as expensive. 110dB at 2 meters is bass that will be felt in any normal-sized room. It managed to keep a relatively tight leash on misbehavior as well, even if you run it hard which is a surprising attribute for such a low-cost sub. It isn’t easy to push to the point of any audible distortion, and it proves that low-cost subs do not need to have a low quality sound. At regular loudness levels, the bass is very clean and hangs around an exceptional 1% total harmonic distortion: excellent performance from a sub of any price.

Aside from the performance, I would compliment the SUB-1500’s appearance. While it is not ravishingly beautiful, it doesn’t look bad, and the rounded vertical edges even lend it a touch of style. It wouldn’t be an eyesore in a normally furnished living room, which is a feat for such a low-cost sub.

So we find that the SUB-1500 is a very good bargain for the performance that it offers, but this is a review of two SUB-1500s as a single bass system, and that confers several major advantages over a single subwoofer system. The chief advantage of which is the ability to smooth out the damage done to the response by room acoustics. The room has an overwhelming influence on bass, so much so that it becomes the dominating factor in the quality of low-frequency sound. With careful placement, two subwoofers have the ability to mitigate much of the damage that the room will inevitably do. It cannot be overstated how much of an advantage this is. Of course, any subwoofer can become a part of a multi-sub system to combat this effect, but how many do so around $500 all in?

Another major advantage of this dual subwoofer system is the ability to defeat localization. Again, with careful placement, the subs will not draw attention to their position, and this can be especially helpful when using higher crossover frequencies. These subs will likely have more punch than many bookshelf speakers in mid-bass between 80Hz to 120Hz, especially lower-cost bookshelf speakers which is what these budget subs are likely to be paired with, so it could make a lot of sense to try higher crossover frequencies than the standard 80Hz. A pair of these enable the user to do that without shifting the soundstage to the spot a single subwoofer is located at.

There is also the output advantage that can be had with dual subs, and with the SUB-1500, that really stacks up at 40Hz and above. This $520 dual sub system has mid-bass output that many $1k subs cannot match. My experience when listening to electronic bass music easily ranked this system at the top of all equivalently priced systems for that type of content. If you like heavier electronic music, this system sounded great, period, regardless of price. The sound of the beats and bass lines from this system was massive.

At $520, a pair of Dayton Audio SUB-1500s is a very formidable subwoofer system and, depending on the buyer’s goal, may be perfect for their purposes. Those looking for very deep bass may want to look at other solutions, but those who want a hard-hitting bass for music have a terrific option in these subs. I was very pleasantly surprised in reviewing these subwoofers and had a blast listening to them for some of the more energetic electronic music in my collection. If that is what buyers are looking for, I don’t think these can be beaten for the price.  

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