
Now defunct, Onix was a relatively new company when my dad had reviewed the home theater set of these RS750s, the RS250s and the “Bigfoot” Center channel speaker in his system back when I was a kid. I still remember that he was generously told to keep these because of his review of the system, which was to say nothing less than special. Now, as you may have seen from the showdown between his long-time reference the NHT Evolution T6 and the Revel Ultima Studio, the loser had to give its place, and was hence “downgraded” to the other system in the house. And that was where these RS750s had secured its place in the long run as well. Since these were kicked out of it’s long-time home, naturally, they came to my room, and at least for the time I will have them (I wasn’t told to keep them so I’m not assuming I will. I think he has other plans for this), I will of course, as customary, do a review of them. For such a golden opportunity as to review tower speakers that my system had never had, I would be a fool to pass this up. Because I don’t have a home theater/stereo set-up, I will mostly be critiquing these more so musically than in a home theater setting, but I will still share my thoughts on them in that aspect. So, onto the meat.
Set-Up

For this review, because of what I have at hand, I am using the same components, as well as different components than my usual main. Essentially, doing several set-ups, one of which is a pure stereo set-up, in which I eliminate my Subwoofer for this review for the majority of the review because of issues, as well as to test if I don’t really feel the need for subwoofers in everyday listening with these towers. I am also just using a stereo preamp DAC that I was borrowed, the PS Audio Stellar Gain Cell, which was recently reviewed by my dad, running the DAC as well as preamp to the Emerald Physics 100.2SE amp which is then powering the RS-750 directly. In the other set-up adds the typically usual NAD T747 receiver and the Music Hall DAC15.2, but this time with the NAD actually acting as a really bulky preamp to the Emerald Physics 100.2SE amplifier. The amplifier to the NAD receiver is then actually driving the Velodyne Subwoofer using my old Ultralink Audiophile reference series 16 gauge speaker cables, crossovered at around 45 Hz using the sub crossover and volume adjusted accordingly to taste. Not too much, but just right. Then of course, my usual set-up, which is changing permanently after this one, because of my “acquisition” of the Emerald Physics for future reference. All set-ups used the USB output from my laptop, and whenever possible using Qobuz to listen and evaluate music in the highest resolution possible for the highest realized potential of the speakers, but also using Spotify at times to see how it handles itself with not as great sources.
Specifications
â—Ź System: Three-way, five-driver direct-radiating system, vented enclosure with two rear-firing flared ports
â—Ź Drivers: Vifa Ring Radiator tweeter, four custom 5.25″ long-throw aluminum cone woofers
â—Ź Crossover: Tweeter at 3.8 kHz, progressive array, variable slope
● Frequency Response: 38 Hz to 20 KHz (± 3 dB)
â—Ź Impedance: 6 Ohms nominal
â—Ź Efficiency: 88 dB (@ 1 watt / 1 meter)
â—Ź Power Rating: 25-200 Watts power handling
â—Ź Dimensions: 37.5″ H x 15.5″ D x 9″ W (953 x 394 x 229 mm)
â—Ź Weight: 56 lbs (25 kg) each; ship weight = 72 lbs each
â—Ź Price: $1399/pair (new)
Also included: Optional risers ($99/Pair)
(Taken from this review of the Onix Rocket Home Theater 5.0 system review from Secrets of Home Theater and High Fidelity vault, of which these are the very pair reviewed then as well)
**NOTE: No longer produced. Company producing them is no more, so these are not produced anymore.
Listening Bias
I tend to look for the bass first in any system, because I think it the bass affects the emotion of songs, as well as the most important aspect that gives a song it’s beat and atmosphere. Even in the presence of the bass, I think the others is as important, like the treble and the mid range, which makes up for most of the frequencies, but the bass is just what I inherently feel for first. I still think everything is very important in creating a soundstage, imaging as well as the realism in audio production of the product that I’m reviewing so, I’d like to say I give everything as equal attention as possible when doing a review. If anything, the second thing I look for is the realism, in instruments like the drum set and specifically like the cymbals, and a very close third or tie for second is imaging and soundstage that is presented to me, as I really sit in the middle and listen for where placements of things as well as where it seems to be playing at, like a concert hall or a studio.
Build Quality
If there is anything different between the RS750 and the RS250, it’s the fact that the face width for the woofer and tweeters are noticeably different. There a more oval shape to these speakers versus the RS250, mostly because it sports smaller 5.25″ woofers than the bookshelf sister at 6.5″, and has 3 more woofers to accommodate the mid and lower frequencies. The woofers and tweeter cover pretty much the whole face of the speaker, and it brings me joy that it uses all the space on the face, without leaving much to just the emptiness of the enclosure patters. The differences are pretty much just those from what I can see. The tweeter is the same Vifa Ring Radiator tweeter as the one of the RS250, and the finish is the same, as they are from the same set. As the height of the main enclosure can be a little short for some listeners, there is a set of risers that are optional that are included as part of the speakers for review, which bring the tweeter to a height close to ear level where I’m sitting at my table, which has a table height of about 31″. As such there isn’t much of a need to tilt these speakers like the RS250s because the tweeter and the top woofer actually sit higher than the RS250 with stands. In attempting to test the enclosure the only way I can, by knocking on them, you can tell how rather dense they are, as well as how sound braced they are. They aren’t the densest I’ve tested out there, but they are quite dense for a big enclosure system.
The grille is a rather long but flexible grille, which makes me think they are a little on the fragile side. However they have lasted since their initial review in 2003 (of which they have survived 2 cross-continental moves with original boxes and padding), so they are durable enough to survive with care and careful repackaging if you ever move. They are pin and cup type grilles held on by the cups that are on the speakers, 6 in total, 3 on each side on the top, middle and bottom. Looks-wise, they are actually very handsome speakers, just by the woofer and the tweeter alone. I really like the look of a fully coned woofer with no interruptions in the woofer cover unlike those with an obvious dust cover. Based on looks-wise as well, I would also like to think they are S/O friendly, since my mom found no qualms about it. They definitely don’t look like your typical speakers that sport the rectangular shape. Because of that however, these moderately weighted 56lbs speakers are actually a little harder to carry or transport, not only because of the shape, but also because of the matte finish on the Rosewood veneer.
The connectors it the rear are some high quality posts that can fit larger gauges of wires bare, but since there is only one pair they don’t give you the option to bi-wire or bi-amp. The posts are also more towards the middle of the speaker enclosure, so when looking for speakers cables do note that you may need a slightly longer cable to tuck it into the rear of the speaker. Like the RS250, the top and bottom of the enclosure sport some sort of glossy piano black slab of MDF that seem to be denser then the enclosure. Included risers also sport that same glossy piano black look as those top and bottom parts of the speakers, and the rest is a Rosewood Veneer with a matte finish. Only those resist fingerprints much better than the piano black gloss parts. Like I said in the beginning, these are one handsome pair of speakers.
Sound Impressions
In terms of the open-ness of the speakers, these are actually not the most transparent or accurate speakers I’ve heard, especially with the grilles on. The original review on secrets did actually say the same. I will say that they sound like they have a thin veil in front of anything it plays and portrays with the grilles on. These are one of the rare speakers in my experience that are truly the best with the grilles off, unleashed from the actual veil of the grilles. As such, this impression is done mostly with the speaker grilles off. During the review period, my Velodyne subwoofer was out of commission for a little bit, and it was a great opportunity to test these speakers without them in pure stereo mode to actually see if they could handle playback by themselves without a subwoofer to aid in the lower frequencies. I’m very glad to say that these handle very well, with actually a lot of songs seemingly not needing the extension provided from the subwoofer to sound great overall. I could almost live with these and abandon my Velodyne sub. Adding them, however, adds much more completion to the overall system portrayed with these speakers. I would say that if you are getting these for the general music playback mostly containing classical or the like, you will be set without a sub. For most other genres out there, although these can go to 38Hz, you’ll still feel the need for a sub to bolster and extend the lower ranges for the songs that take advantage of them.
The meat of this speakers, despite their slight lack of open-ness, is actually in the imaging. These image crazy good, to the point that any flaws I’ve had with my cold creme banana plugs with the cables are easily exposed. If everything is positioned correctly, and it’s a little off. I check and redo my banana connectors, not the speakers. It’s solved the imaging issue twice already when the right side ends came a little loose (I’ve permanently solved the issue after the second time around). When they are perfect, the vocals are right there in the middle of the two speakers very clearly, the speakers disappear. Not to mention, the very tricky in-between areas, which are those that are between the center of the speakers and the speakers themselves are very well presented. Other speakers can sort of do them, but these pull them off.
Realism of these speakers are as expected, really good. They are actually more refined than the bookshelf sisters. Another thing that was realized through the use of the Emerald Physics 100.2SE in the set-up where I have my Music Hall DAC15.2, NAD T747 receiver as a preamp to the Emerald Physics amplifier which powers the RS750, and the NAD receiver amplifier as the speaker level output to the Velodyne DLS-4000 sub, was the audible improvements in overall sound. Imaging, soundstage, realism, bass was much better with better gear. So that is to say, these speakers can still be improved and grow with their system and components, to a certain point.
Overall their sound characteristics are on the warmer side, just like the sister RS250 bookshelves I reviewed. With the lower extension, their signature sound, and imaging, they really excel in presenting you a stage, if the mastering calls for. In certain songs, the sound can even extend beyond the speakers about maybe 1 inches outside, which is impressive, and I’ve only heard better in my dad’s system.
Heize’s Lyricist

Heize is a multi-talented Korean artist whose songs will top the charts in Korea. I chose her song because Lyricist, the title song in her most recently album, showcases the RS750’s talents very well. Although she is well known as a rapper as well, this song doesn’t have her rap at all. It showcases her slightly raspy yet delicate voice, with a piano, some metal percussion, vocal harmony, a drum set, electric guitar and acoustic guitar in this soul/jazz song. The song itself translates to the frustrations of a lyricists, true to the title, in which she can’t stop writing lyrics despite everything she is going through. It’s a “fancy” sounding song. The staging is clear, She is in the middle, with a drum set behind her, her supporting vocals are left and right, the electric guitar behind her as well interjecting at times. One of the more constant sounds in the song is tapping on the drum rim with the drumstick, which is conveyed convincingly and yet clearly in the distance behind her, slightly to the left. The cymbals are also nicely metallic and ring as such. Even in pure stereo without the sub, this song sounds complete and full. You definitely don’t need a sub for a song like this despite the seemingly deep, warm and punchy drum set bass in the background setting the almost constant beat. Some simple and jazzy piano envelope you in the song, which is a very nice bar-like atmosphere, making it seem like the ramblings of a rather successful person. There is a verse in the song where there is a muffled conversation with piano, giving a more airplane announcement feel, giving the song some unique classy rich feels I cannot simply describe. It changes the seemingly simple song to a make it slightly more intense, and this song does so in a nice spot and makes the whole song interesting for the whole 3 minutes, conveyed very very nicely with the RS750.
Jurgaz’s Arab Nights

I came to know this song from the Bass Nation playlist on Spotify, and this song is a great example of the different types of bass you can experience on songs. This trap song is one I like to listen to, with a nice beat and energy, and despite the repetitiveness, it’s actually not a drag to listen to. Most of the songs contain this punchy mid-range sounding bass, and those are the ones that the RS750s can actually handle very well, giving it a very nice warm punchy and relatively tight bass. However, when the deeper bass in one of the middle verses comes in, the RS750s roll off, showing the flaw in the non-“true” full range tower frequency response of 38Hz at ±3db, and adding the sub actually makes it audible. Although that deep bass is of softer dynamic and you probably don’t really notice it, doing an A/B with and without sub with this song makes it clear that a sub will help, but for a lot of the songs, you can actually get away with just these towers for your music reproduction, but you plan on using these for more home theater application, these will definitely need a sub to reach those lows and that punch on explosions or action in those movies.
Conclusion
Onix Rocket RS750s are very well made floorstanding speakers that sports looks that would still be beyond the norm today. These speakers have survived several moves and will last when treated properly. Even after many years of use, these speakers hold up very well, with the finish looking almost brand new. As they are not very open sounding with the grilles on, these are truly released with them off. Quality parts such as the Vifa Ring Radiator tweeter along with the many 5.25″ long-throw aluminum woofers presents a full sound with a warm punchy bass that many songs won’t feel the need for a subwoofer. The warm overall signature characteristic to the sound is less fatiguing to the ears, and other than the woofer size and quantity, these are actually better overall than the RS250 bookshelf sisters in imaging with a very tight center that pinpoints the singer, as well as any flaws in your placement or gear. Realism and instrumental separation is still as superb in the family, and if you can still find any in the wild in the used market, these are a rare gem that you should consider purchasing, that can provide enjoyment in most music or audio you listen you.
All components used in this Review
- Playback: Lenovo P43s Laptop USB
- DAC: Music Hall DAC15.2
- Amplifier/preamplifier: NAD T747 7.2 channel receiver, Emerald Physics 100.2SE 2-channel amplifier
- Interconnects: Audio Acoustics Cables, Straight Wire Flexconnect II interconnects,
- Speaker Cables: MonsterXP compact precision stranded high resolution speaker cable with magnetic flux tube and LPE dieletric -1R, Ultralink audiophile reference series 16 gauge speaker wires,