SP601 — Bronze Beauty, Pragmatic Performance

[jeromeof]

Bronze Flair Meets Everyday Pragmatism​

The Fosi Audio SP601 is Fosi’s first passive bookshelf speaker—and it makes a statement. With its bronze-colored woofer (a Fosi house aesthetic that coincidentally nods toward Klipsch’s copper look) and clean, modern cabinet reminiscent of Q Acoustics, the SP601 looks far more expensive than it is. Even better, it brings genuinely engaging sound with room to scale up if you give it a touch of EQ or pair it with something like the WiiM Ultra for room correction.


Note: This is a cross post of my review on my blog Pragmatic Audio
I bought the SP601 as part of last year’s kickstarter campaign for the V3 Mono’s,but while the V3 Monos arrived as soon as the kickstarter completed and the SP601 was delayed for nearly a year.
If you’re interested in learning more about this product, you can find details at Fosi Audio’s product page.

And I actually first heard the SP601 at this year’s Munich High‑End where, despite being one of the least expensive speakers on display, it absolutely looked at home among some far pricier models. Having finally arrived, it has proved to be a pragmatic, living‑with‑it‑every‑day kind of speaker, easy to place, visually striking, and mostly satisfying out of the box. And ultimately when corrected for room using some room ‘correction’ tools it sounds great at least in the different spaces I tried it in.
So was it worth the wait? Read on to find out.

Unboxing and Build Quality​

The SP601 arrives in a large but well-protected box:

Opening this box reveals some foam protection and the manuals:



Removing this protective packaging reveals the speakers:



Taking the speakers out reveals the cabinet:



The cabinet feels solid with tidy seams:



But the most striking thing is the beautiful design with rounded edges that give it a contemporary, Q Acoustics‑like vibe:

The grills are nicely made but they do have very strong magnets:



Binding posts are solid, and the overall build inspires confidence at the price



The only thing I noticed, that the SP601 was a little lighter than I expected. I imagine this was to keep the weight down as shipping very heavy speakers can be expensive, but it did make me think that the internal bracing was a little lighter than I expected.

Deep & Textured Bass​

Fosi’s in‑house 6.5" HybridCone woofer pairs a paper cone with an aluminum outer layer. In practice, that means you get natural tone and punch with better control than typical paper cones alone. Bass lines can sound more textured and stay articulate at reasonable listening levels.

Of course, the overall look of the woofer is like a classic Klipsch speaker and I really like the way it looks, so I mainly used it without the grills.

Optimized Reflex Design​

The rear port is tuned to reduce standing waves and muddiness, adding extension without sacrificing control. You can get surprisingly full bass even near a wall, though 20–30 cm of space still yields the best balance.

Natural Treble Clarity​

A 1.5" silk dome tweeter, set in a precision‑cast aluminum waveguide, gives smooth, fatigue‑free highs with wide yet controlled dispersion. It helps the SP601 throw a more open soundstage and improves focus at the listening position.

Flexible Wiring​

Dual‑mode binding posts accept banana plugs or bare wire. Setup is quick for beginners and robust for long‑term use.

Erin Audio Corner Measurements​

Before I get into the performance of the SP601 I think it is important to recognise the measurements performance by Erin Audio Corner, with his Klippel Nearfield scanner.
Below is in-room response from Erin’s Audio Corner review showing the in‑room response behaviour.

The most obvious aspect of this measurement is the peak in the treble and some unevenness in the midrange.
Reference: Erin’s full review is worth reading for detailed anechoic measurements and analysis: https://www.erinsaudiocorner.com/loudspeakers/fosi_sp601/
Note: Erin didn’t know final pricing at the time of review and compared performance to much more expensive competitors; at the SP601’s eventual retail price, I think the value context shifts considerably, especially when you factor in room correction.

Room Setups and Real-World Performance​

I’ve tested the SP601 in two different room configurations, each highlighting different aspects of these speakers’ capabilities.

Front “Games” Room with WiiM Ultra Room Correction​

My primary listening space is a front “games” room where the SP601 shines with the help of WiiM Ultra’s RoomFit correction. This setup was particularly revealing of the SP601’s true capabilities when freed from room-induced coloration.

The WiiM Ultra’s RoomFit technology proved to be an excellent match for the SP601, addressing two key areas:

1. Bass mode correction - The automatic room calibration tamed resonant bass frequencies that were causing some bloat in this particular room. After correction, the bass became significantly tighter and more defined.
2. Treble linearity improvement - The SP601’s treble, which can occasionally sound a bit uneven, was smoothed out beautifully by the WiiM’s correction.

In this room, the SP601 delivered its most refined performance. The corrected frequency response allowed the speakers to disappear into a coherent soundstage, with imaging that belied their modest price point. This setup convinced me that with proper room treatment or DSP correction, these speakers can punch well above their weight class.

Secondary Room with Complete Fosi Audio Stack​

I also tested the SP601 in another room alongside a suite of other Fosi Audio equipment, creating an almost all-Fosi system. I still used the WiiM Ultra and used its bass managed to augment the SP601’s bass with a KEF Kube 10 subwoofer.

This setup included:

• Fosi Audio SP601 speakers
• Fosi Audio V3 Mono amplifiers
• Various other Fosi Audio components like the LC50

While this setup was an interesting experiment that showcased the brand synergy, I ultimately found that the SP601 performed better in the games room with the WiiM Ultra’s room correction. In this secondary room, the speakers still delivered an enjoyable listening experience, but room interactions were more noticeable without needing a subwoofer.
This comparison between rooms highlighted an important characteristic of the SP601: its performance scales significantly with proper room placement and correction. In the right environment (or with the right DSP), it transforms from a good speaker to an exceptional value that goes much deeper than the price bracket.

Sound Impressions​

Bass​

Out of the box, the SP601 offers surprisingly full bass for its size. Extension isn’t subwoofer‑deep, but the mid‑bass has satisfying punch and a touch of warmth that flatters modern pop and rock. On Billie Eilish’s “bad guy,” the kick is present and tuneful; on Daft Punk’s “Giorgio by Moroder,” bass lines stay articulate without getting boomy when the speakers are at least 20–30 cm from the wall.

Midrange​

Vocals come through natural with a slightly forward presence that helps dialog and singer‑songwriter tracks. Acoustic instruments carry decent body; guitars on John Mayer’s “Slow Dancing in a Burning Room” sound convincing with enough texture to keep things engaging.

Treble​

Treble is detailed and lively, occasionally drawing attention to bright recordings. This matches what I heard and what Erin measured—there are some irregularities up top that can make certain cymbal hits a bit splashy. The good news: a light EQ shelf and a couple of narrow cuts smooth things out beautifully, or you can let the WiiM Ultra’s room correction handle it automatically.

Soundstage & Imaging​

The stage is wider than expected for the class, with stable center imaging. Depth layering is decent, and with a small toe‑in and stands bringing the tweeters to ear height, imaging locks in convincingly. Compared to pricier designs, you don’t get the holographic wrap‑around—yet placement cues on tracks like “Keith Don’t Go” still land with confidence.

Specifications and Measurements​

• Type: Passive 2‑way bookshelf speaker, rear‑ported
• Tweeter: 1.5" silk dome in precision‑cast aluminum waveguide
• Woofer: 6.5" in‑house HybridCone (paper core with aluminum alloy outer layer)
• Power handling: 80 W RMS / 160 W peak (per speaker)
• Nominal impedance: 6 Ω
• Sensitivity: 88 dB (2.83 V/1 m)
• Terminals: Dual‑mode binding posts (banana plugs or bare wire)
• Finish: Matte cabinet with bronze‑accent woofer

Measurement Setup and Comparisons​

To quantify the SP601’s performance, I decided to conducted some of my own in-room measurements using a calibrated measurement microphone and Room EQ Wizard software. Here’s the measurement setup I used:

I captured measurements at the primary listening position, approximately 1 meter from the speaker in both on-axis and off-axis configuration. I then compared the SP601 with the Q Acoustics Q3020i, which occupies a similar price bracket and design philosophy.

Frequency Response Comparisons​

The in-room frequency response measurements reveal interesting similarities and differences between the SP601 and Q3020i:

The measurements show that both speakers have a similar overall balance but with some key differences:

1. The SP601 exhibits slightly recessed lower midrange (200-400Hz)
2. The Q3020i has a more treble response above 7Khz
3. Bass extension is better in SP601 has a bit more mid-bass energy

Looking at the off-axis response (so pointing out into the room - parallel to a back wall ), we can see how the speakers behave when listening from different positions:

The SP601’s off-axis behavior is well controlled, with a reasonably smooth transition with the 2K-4K dip filled and less of a roll off than the Q3020i. Overall I feel it has a more balanced speaker in an off-axis setup.

In Room EQ Recommendations ​

Using REW for the on-axis response this would be the recommended EQ.

Note: while there are obviously room modes in this in-room measurement, I see a similar peak in the 5K region that Erin measured with his Klippel. Fixing this with EQ would be relatively simple.
But since I had decided to put these speakers pointing out into the room (off-axis), I thought it is better to look at the possible EQ for the off-axis response and again I think the EQ look minimal (if required at all) beyond the bass 'room modes' issues that are nothing to do with the speaker:

Real‑world pairing: I had excellent results with the WiiM Ultra handling preamp duties and room correction into a compact Class‑D power amp. The WiiM Ultra’s auto‑calibration cleaned up the treble and tightened the bass, addressing exactly the kind of inconsistencies that can show up in rooms—and which Erin from Erin’s Audio Corner highlighted in anechoic testing.
So, with these simple corrections applied, I felt the SP601 sounded remarkably for the price even before adding a subwoofer and I think its great that Fosi Audio have now launched a Subwoofer which should fill in that sub 100Hz region nicely, specially when using say the ZP3 (with the High Pass Filter configured) or a Preamp with room correction like the WiiM Ultra.

Comparisons​

Q Acoustics 3020i​

The Q3020i makes for an interesting comparison, as both speakers occupy a similar price bracket and aim for an engaging yet refined sound:

• Treble Character: The 3020i has an even softer, more relaxed treble; SP601 is a bit more lively and forward in the top end. In measurements, this shows as a smoother high-frequency roll-off in the Q3020i versus the slightly more energetic treble response of the SP601.
• Bass Performance: Bass quantity is comparable between the two; the SP601 can feel punchier near walls but benefits from some space. The measurements show similar extension, though with slightly different mid-bass emphasis.
• Midrange Presentation: The Q3020i has a slightly more recessed midrange, while the SP601 brings vocals a bit more forward in the mix. This was evident both in listening and in the 2-4kHz region of the frequency response measurements.
• Build and Aesthetics: The Q3020i has a more understated, traditional look; the SP601 makes a bolder visual statement with its bronze woofer. Both are well-built, though the Q3020i’s cabinet feels a bit more premium in hand.
• Listening Preference: If you like a laid‑back, forgiving listen, the 3020i still charms; if you want more energy and visual flair, the SP601 wins.

In my measurements, the SP601 demonstrates more potential for improvement with EQ than the Q3020i, which is already quite well-balanced out of the box. However, this also means the SP601 can be tailored more precisely to different room acoustics and listening preferences.

Rating​

Pragmatic Rating: 4/5 — At its actual retail price, the SP601 offers standout aesthetics and enjoyable sound. It’s easy to recommend if you’re willing to take advantage of basic EQ or room correction.

• Strengths
  • Striking looks that read as “premium” in person
  • Punchy, satisfying bass for the size
  • Scales well with EQ/room correction (WiiM Ultra synergy is excellent)
  • Great value at retail pricing
• Limitations
  • Treble can be a touch lively/uneven in some setups
  • Benefits from stands and placement care

With EQ: 5/5 — If you pair the SP601 with a capable streamer/preamp like the WiiM Ultra (or run manual EQ), the tonal balance smooths out and performance jumps a class.
I can understand Erin’s Audio Corner’s assessment of these speakers when judged purely on their anechoic performance, but I believe that real-world context matters. For the price, the build quality and bass performance are superb, and with some basic EQ corrections, these become great value speakers. The 4-star rating reflects their performance in context of their price point and the fact that with minimal effort, they can be transformed into excellent performers.

Conclusion​

The Fosi Audio SP601 is a confident debut speaker: visually arresting, fun‑sounding, and appropriately priced. It looked right at home in Munich among far pricier fare, and in my room it proved that a bit of thoughtful setup—and ideally some EQ—turns it into a remarkably complete package for the money.
My testing in two different room setups confirmed that these speakers have impressive potential, particularly when their few frequency response quirks are addressed with room correction. The front “games” room setup with WiiM Ultra RoomFit proved to be their ideal environment, where they delivered performance that genuinely surprised me given their price point.
If you want a bookshelf that looks great in living spaces and delivers “smile‑factor” sound, the SP601 is an easy shortlist pick. Add room correction, and it becomes a small‑room hero.