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.