“Let our rigorous testing and reviews be your guidelines to A/V equipment – not marketing slogans”
Facebook Youtube Twitter instagram pinterest

Outlaw Audio Ultra-X13 Subwoofer Listening Tests


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. Receiver used was a Pioneer Elite SC-55 with a variety of different speakers, and the crossover was used mostly at 80 Hz and also 100 Hz at times. Since room acoustics have a huge effect on low frequencies, the way this sub sounds in my room at my listening position is not necessarily going to be the way it sounds 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. Most listening was done with both ports open and the EQ switch set to ‘EQ 2.’

Music Listening

One album that I listened with the Ultrflightofthecosmichippo.jpga-X13 was ‘Flight of the Cosmic Hippo’ by Bela Fleck and the Flecktones. This eclectic instrumental album is a fusion of bluegrass, bebop, and jazz and has superb bass guitar playing from bassist Victor Wooten. It is popular among audiophiles for demonstrating the bass prowess of their speakers, not just for Wooten’s deft bass wizardry but also for some of the beefy electronic percussion from their percussionist “Future Man.” This is an album that can make near constant use of a subwoofer, although usually the usage is subtle and is not the flashy boom and rumble that other subwoofer demo material will get into. This album is a great way to demonstrate the subtlety that a well-integrated subwoofer can add to a music-listening experience, simply by switching the subwoofer off in middle of a song. The subwoofer doesn’t seem to be contributing much to the experience until it is turned off, at which point it is as though the foundation of the music is pulled out from under it. A good, well-integrated subwoofer is mostly invisible on playback but is still crucial to its experience, at least if the main speakers are not truly full-range. There are moments where subwoofer use is clear, such as the title track that has a lot of energy in the mid 30 Hz and 40 Hz range, and is such a ‘bottom dweller’ of a recording, in the sense of having so much low-frequency energy, that it is obvious that the sub is doing most of the heavy lifting.

The Ultra-X13 proved to be as adept with monster loads of raw low-frequency bass as it was with merely providing a subtle foundation...

On “Flight of the Cosmic Hippo”, the Ultra-X13 blended the bass of the subwoofer band with the main speakers very well. After a few tracks I even ran the sub a few dB hot just to see where I could get it to ‘reveal’ itself on this album, and it still maintained its invisibility aside from giving the kick drums a bit more punch. But when I turned it off, the bottom of the sound falls out and a big chunk of the music is lost. The Ultra-X13 followed the fundamentals of the tuneful and complex bass lines with precision. Percussion has the room-filling, low-end punch called for by the sound mix. Some people might look at a large ported, design like the Ultra-X13 and assume such a subwoofer is made primarily for movie explosions, but that is definitely not the case. The Ultra-X13 is made to reproduce the source content without adding or subtracting anything that the sound engineer intended, and this philosophy was very evident in the time I spent listening to “Flight of the Cosmic Hippo.”

Another album I tried on the Ultra-X13 was a recordinSymphony_No_12.jpgg of Symphony No.12 ‘Lousto’ by the Finnish composer Kalevi Aho. This composition and recording is truly epic. It uses two orchestras: a chamber orchestra and a full orchestra, each on opposite sides of the audience. On all sides of the listener are different types of horns and percussion, and to get the full effect, this recording should be listened to in its surround sound SACD format with a corresponding setup. It may well have the best use of surround sound for music recording I have heard yet. It is no slouch in subwoofer frequencies either, with tremendous use of bass drums in the first and last movements. In Symphony No.12, the bass drum playing revolves all around the listener, not because the sound engineer is panning the sound, but because the percussionists are situated all around the listener. This colossal performance requires 120 musicians sprawled all around the audience, and the end result is a towering, monumental sound.

The Ultra-X13 gave the bass drums weight and a sharp attack. The thump of the attack could be felt as well as heard when the drumming was at its most intense. This album has a very wide dynamic range, so the drumming ranges from soft to very loud. If played at reference levels, they can get strikingly loud, and this album has to be played back loud to do its dynamic range justice. I cranked the volume and the Ultra-X13 kept pace. I could feel my sofa taking a beating from the sound pressure waves generated by the subwoofer. Throughout the recording, the bass sound of the Ultra-X13 was cohesive with the main speakers, and with the exception of the vibration of my sofa, I never felt it to be separate; the sound was unified. I do think that the full might of this Symphony No.12 would require more than a single Ultra-X13 is capable of, not because the X13 is in any way weak, but because this recording is extremely demanding in dynamic range to reproduce at realistic levels. I am not sure anything but the most powerful commercial subwoofers would be able to tackle Symphony No.12 single-handedly. I think, however, that a single Ultra-X13 would suffice for the loudest levels at which most people would ever care to listen to ‘Lousto’.     

An album that I thought wSymphony_No_12.jpgould make for a great test of a subwoofer’s ability for nuance as well as force is Lustmord’s “Carbon / Core,” released in 2004. This album would fall into the genre of dark ambient although there is a bit more drama here than one would find in typical atmospheric ambient music. To me it sounds like the music score for a slow-burning but wicked science fiction/ horror film. Sometimes it is purely atmospheric but in some moments it can be aggressively forward. Sounds of distant drones are superseded by dissonant bells, swarms of mechanical creatures, subterranean thuds, and other anxiety-inducing sounds. They are all artfully arranged and would make a perfect accompaniment to a gallery exhibition of H.R. Giger landscapes. The bass can hang back subtly in recessed hums or creep forward in looming drones, but at some moments the bass can burst forward in grinding, guttural blocks of aural assault. Lustmord is not afraid to dig deep for his bass sounds, and frequencies below 30 Hz are often present on this album.

The Ultra-X13 handled “Carbon / Core” with the same finesse that it reproduced the more earthly music that I had given to it heretofore. Passages of clean low frequency content were easily distinguishable from passages that were rich in harmonics and therefore thick with richly textured sounds. Deep rumbles, thunderous growling, and undulating buzzing noises were all distinct on the Ultra-X13 as opposed to a single booming noise that a low-quality subwoofer often reduces those different sounds to. The Ultra-X13 only made its presence known when the music pushed it into low-frequency playback of such depth and magnitude that was clearly beyond the capabilities of the main speakers. Outside of those moments, it made for a seamless partnership with the main speakers. “Carbon / Core” is a nightmare world of music, and the Ultra-X13’s fidelity helped to realize that world with a level of vividness that I imagine would give anyone a sense of apprehension.

For something that makes far less subtle morus_against_the_world.jpge and more explicit use of subwoofers, I turned to the genre of “Drum and Bass” music, where low-frequency content is nearly maximized. “Drum and Bass” is a rather literal name for this genre, since it serves as a descriptor as well, being a music made largely from bass and percussion. I choose the 2005 album “Us Against the World,” a mix by ‘D’n’B’ duo Evol Intent. This album is on the harder end of Drum and Bass, and the bass here is brutal, heavily compressed, and unrelenting. It’s rough stuff, and the subwoofer gets near constant use.

The Ultra-X13 proved to be as adept with monster loads of raw low-frequency bass as it was with merely providing a subtle foundation for much more restrained types of music. The percussion and bass were utterly visceral. The bass lines gave me a buzzing sensation along my spine, and I felt the kick drums in my chest. The Ultra-X13 was hitting so hard I could even feel the toms. No doubt that my seating in such close proximity to the sub was a major factor in these tactile sensations, but the point was made that, in the right conditions, the Ultra-X13 can be an utterly bruising subwoofer. I decided to have some fun and run the bass super hot for a while to see how much of a beating the Ultra-X13 could take and also to see how much of a beating I could take. Who would break first, me or the sub? It turned out to be a draw; the album finished before I gave in or the sub gave up. I have to admit to feeling slightly battered afterward, but the subwoofer didn’t seem to be any worse for wear. I can report that the Ultra-X13 is a great choice for bass-heavy electronic music.

Movie Listening

One movie I listened to with the Uledge_of_tomorrow.jpgtra-X13 was the 2014 Tom Cruise film “Edge of Tomorrow.” This science fiction opus is notorious for the low frequency content in its opening credits, with strong tones starting at 30 Hz and stepping down in 5 Hz increments to 10 Hz where it nearly saturates the dynamic range to full scale in the sound mix. Among connoisseurs of infrasonic content (and yes, such people exist), it is known as one of the toughest scenes of any sound mix to fully reproduce. It is generally not a good idea to crank this scene with just any subwoofer, because if there was ever a scene that could make a subwoofer bottom out, this is it. Yes, I cranked the opening scene of “Edge of Tomorrow” to reference level, because I wanted to see how well protected The Ultra-X13 was. To be sure, that is something I would be hesitant to do with my own subs, and if the Ultra-X13 didn’t survive, I could just weasel out of responsibility by telling Outlaw Audio that the sub needed a bit more work. Happily, such evasion wasn’t needed, as the Ultra-X13 barreled through the scene without any sounds of distress. 10 Hz is well below the tuning point of the sub, and it wouldn’t have been able to produce a lot of sound at that frequency, but the point of the exercise was to see how well protected the Ultra-X13 was, and it passed with no problems.

The rest of the film was reproduced with the force and precision that was standard operating procedure for the Ultra-X13 by that point. Explosions, crashes, gunfire and other warfare sounds mixed in science fiction sounds such as aliens burrowing underground and ambushing soldiers on the Edge of Tomorrow sound mix, and it all sounded quite convincing with the Ultra-X13. Given what I understood of its design, none of that came as a surprise to me. High linearity means that the subwoofer will be able to handle any kind of content with equanimity.

Another movie I watched using the Ultra-X13 was the 2015 science fiction sThe_Martian.jpgurvival film “The Martian.” I choose this movie for something that will take advantage of the subwoofer but doesn’t hammer it all the time. When bass is used constantly, it becomes numbing as the listener acclimates to it. Low frequencies can be much more effective when used sparingly. The Martin does not pound the listener into submission like a war film, so when there are some big bass moments such as a rocket launch, it is all the more striking.

In the moments during The Martian where the subwoofer was called upon, the Ultra-X13 was resounding. Martian storms shook the room, and the occasional blast had a concussive punch. Harry Gregson-Williams’ music score gave the sub some work to do as well and was not averse to electronic sounds, so the Ultra-X13 was able to shore up the music during its more tense passages. It may be that a movie sound mix that is bloated with bass can disguise the shortcomings of a lesser performing subwoofer, so it is sound tracks with more restraint like this one that can expose how accurately the subwoofer is reproducing the sound. If so, the Ultra-X13 sounded like it was on point for this sound mix. When I was watching this film with the Ultra-X13, it didn’t sound as if the bass was coming from the subwoofer; it sounded as though it was simply the soundscape of the movie. For a film like this, that is what any speaker should sound like- as though it does not exist, and the sound is emanating from the setting. 


Confused about what AV Gear to buy or how to set it up? Join our Exclusive Audioholics E-Book Membership Program!

Recent Forum Posts:

ryanosaur posts on January 05, 2020 23:01
Id put a third in my room if I could… but something would have to give.

Might be the relationship. :oops:

But in a 8000'3 room, I think a third would be ideal, along with two full range towers tickling 20Hz. Alas, I digress.

Still happy with my Outlaw gear after 1 year!
KEW posts on January 05, 2020 16:25
MrKaffee, post: 1360528, member: 90469
I now have two of these. Bought one last year and another this year. Took advantage of their Christmas specials at $999 free shipping. All I can say is wow! One was really good but two is simply outstanding. I have both situated behind the sectional. Deep deep bass and can shake the entire room - not just the sitting area! I had one set at eq2 but found with two set at eq1 to be sonically superior. Have the pre/pro set to large fronts and to mirror low bass below 40 Hz to the subs. It’s amazing how seamless it sounds. Right now I’m in OMG mode but like many of you am in endless pursuit of nirvana.
Yeah, once you get to a pair of these (in any normal room) it becomes a real question if more would really add anything (that you want added). It is like riding a 1100cc motorcycle - there are bigger bikes, but how much more acceleration do you need when you can twist the grip and flip the bike on top of you!
MrKaffee posts on January 05, 2020 15:29
I now have two of these. Bought one last year and another this year. Took advantage of their Christmas specials at $999 free shipping. All I can say is wow! One was really good but two is simply outstanding. I have both situated behind the sectional. Deep deep bass and can shake the entire room - not just the sitting area! I had one set at eq2 but found with two set at eq1 to be sonically superior. Have the pre/pro set to large fronts and to mirror low bass below 40 Hz to the subs. It’s amazing how seamless it sounds. Right now I’m in OMG mode but like many of you am in endless pursuit of nirvana.
andyblackcat posts on August 11, 2018 20:41
Yeah cheaper ones possibly. Always liked to have one of those older M&K subs before the company changed its name? As they show up cheaply now and was around cost of above Outlaw THX sub.
shadyJ posts on August 11, 2018 17:40
andyblackcat, post: 1262768, member: 70814
Well least you know about that as I was thinking what NASA does when pressurizing the shuttles cabin then they check for leaks to see if its okay to launch. So same for speakers/subs I guess as I had to check over older speakers that had drill holes and had to seal the holes then run a loop frequency sweep checking for air leaks and resonate noises.

Still maybe a little silicon going around the plate amp as you may never know there could be one spot where its venting air?
A lot of these amps are already sealed in with glue, along side the screws, so I wouldn't worry about leaks too much with this build class of subwoofer. However, very inexpensive subs may be a different story.
Post Reply