Short answer: the JBL 305P MKII. It ranks #11 of 64 powered bookshelf speakers by sound quality at $319; the Onkyo GX-30ARC ranks #43 and costs $349, so there is not much of a tradeoff to weigh.
What the JBL 305P MKII offers: A fantastic value in studio monitors. Extremely close to the Focal Alpha 50 EVO, almost indistinguishable. Surprisingly deep and wide soundstage. Good horizontal dispersion (~70 degrees). Has a proper limiter that controls output cleanly rather than crudely cutting bass, and holds up well under sustained loud playback with minimal thermal compression. Watch for: Possible slight hissing from the amps at low levels. Rear ported, can be an issue close to walls. A port resonance around 1.6kHz is audible and distracting on some tracks. Midrange is somewhat scooped rather than flat for a studio monitor, and treble runs about 1.5dB hot - Erin’s Audio Corner recommends using the -2dB treble shelf switch. Vertical dispersion narrows around the crossover, so try to stay within about 10 degrees of the tweeter axis.
What the Onkyo GX-30ARC offers: A compact powered pair with unusually complete connectivity: HDMI ARC, USB-C, optical, phono/line, aux and Bluetooth 5.3. Erin’s data predicts a 5.55 score with a subwoofer, low 0.091 on-axis roughness and useful 62Hz in-room extension. Watch for: The response rises about +0.48dB per octave and narrows vertically, while directivity-index consistency is a mediocre 3.84. Its 0.232 sound-power smoothness suggests some room-response unevenness, and low bass still benefits from a subwoofer.
Buy the JBL 305P MKII. It ranks higher for sound quality than the Onkyo GX-30ARC and costs less, so there is no real case for the other one.
Specifications Side By Side
| JBL 305P MKII | Onkyo GX-30ARC | |
|---|---|---|
| Price | $319.00 | $349/pair |
| Ranked | #11 of 64 in Medium Size Powered Bookshelf Speakers | #43 of 64 in Medium Size Powered Bookshelf Speakers |
| Dimensions | 11.7"H x 7.3"W x 9.1"D (297.2 x 185.4 x 231.1 mm) | approx. 8.7H x 5.8W x 7.9D in each |
| Frequency Response | 49 Hz - 20 kHz (+-3 dB) (Manufacturer specified) | - |
| Bass Extension (-3dB) | 50Hz (measured, Erin’s Audio Corner) | - |
| Bass Extension (-10dB) | 43Hz (measured, Erin’s Audio Corner) | - |
| Inputs | XLR, TRS | HDMI ARC, USB-C, optical, phono/line, 3.5mm aux, Bluetooth 5.3 |
| Weight | 10.4 lbs / 4.7 kg each | - |
| Drivers | 5" (127mm) woofer | 1" tweeter, 4" woofer |
| App | No | - |
| Bluetooth | No | - |
| EQ | Yes (Room adjustment) | - |
| Output Power | 81w Per Speaker | - |
| Sensitivity | 91.1dB (measured at 0.3V/1m, Erin’s Audio Corner) | - |
| Enclosure | - | 2-way powered, rear-ported |
| Power Output | - | Class D amplification |
| Outputs | - | Subwoofer |
| Country | - | Japan (design) |
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Prices on this page were last checked August 25, 2026 at 6:19 AM UTC. Product prices and availability are accurate as of that date/time and are subject to change; the price and availability shown on Amazon at the time of purchase will apply to the purchase of this product.
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The Two Speakers In Full
JBL 305P MKII: $319.00 Amazon eBay
Pros: A fantastic value in studio monitors. Extremely close to the Focal Alpha 50 EVO, almost indistinguishable. Surprisingly deep and wide soundstage. Good horizontal dispersion (~70 degrees). Has a proper limiter that controls output cleanly rather than crudely cutting bass, and holds up well under sustained loud playback with minimal thermal compression.
Cons: Possible slight hissing from the amps at low levels. Rear ported, can be an issue close to walls. A port resonance around 1.6kHz is audible and distracting on some tracks. Midrange is somewhat scooped rather than flat for a studio monitor, and treble runs about 1.5dB hot - Erin’s Audio Corner recommends using the -2dB treble shelf switch. Vertical dispersion narrows around the crossover, so try to stay within about 10 degrees of the tweeter axis.
Full JBL 305P MKII review and specifications →
| App | No |
|---|---|
| Bass Extension (-10dB) | 43Hz (measured, Erin's Audio Corner) |
| Bass Extension (-3dB) | 50Hz (measured, Erin's Audio Corner) |
| Bluetooth | No |
| Dimensions | 11.7"H x 7.3"W x 9.1"D (297.2 x 185.4 x 231.1 mm) |
| Drivers | 5" (127mm) woofer |
| EQ | Yes (Room adjustment) |
| Frequency Response | 49 Hz - 20 kHz (+-3 dB) (Manufacturer specified) |
| Inputs | XLR, TRS |
| Output Power | 81w Per Speaker |
| Sensitivity | 91.1dB (measured at 0.3V/1m, Erin's Audio Corner) |
| Weight | 10.4 lbs / 4.7 kg each |
- Links
- Reviews, Comparisons and Sound Samples
- Erin’s Audio Corner Review Measurements More from Erin’s Audio Corner →
- Audio Science Review Measurements More from Audio Science Review →
- Erin’s Audio Corner: LIVE! JBL 305P MkII Powered Studio Monitor Review
- DSAUDIO.review: DSAUDIO.review Focal Alpha 50 EVO vs JBL 305P MKII sound.DEMO More from DSAUDIOreview →
- DSAUDIO.review: JBL 305P MKII vs Yamaha HS5 6-Track Comparison
- DSAUDIO.review: DSAUDIO.review JBL 305P MKII vs KRK Classic 5 CL5G3 sound.DEMO
- DSAUDIO.review: JBL 305P MKII vs Adam Audio T5V 6-Track Comparison
- DSAUDIO.review: DSAUDIO.review Adam Audio A5X vs JBL 305P MKII sound.DEMO
- DSAUDIO.review: DSAUDIO.review Kali Audio LP-6 V2 (2nd Wave) vs JBL 305P MKII sound.DEMO
- DSAUDIO.review: DSAUDIO.review Edifier MR4 vs JBL 305P MKII sound.DEMO
- DSAUDIO.review: Kali Audio IN-5 vs JBL 305P MKII Sound & Frequency Response Comparison
- DSAUDIO.review: JBL 308P MKII vs JBL 305P MKII Sound & Frequency Response Comparison
- DSAUDIO.review: Neumann KH80 DSP vs JBL 305P MKII Sound & Frquency Response Comparison
- DSAUDIO.review: JBL 305P MKII vs PreSonus Eris E5 6-Track Comparison
- Erin’s Audio Corner Measurements (spinorama.org)
- Reddit Search for JBL 305P MKII Review
- Head-to-Head Comparisons
Onkyo GX-30ARC: $349/pair Onkyo eBay
Pros: A compact powered pair with unusually complete connectivity: HDMI ARC, USB-C, optical, phono/line, aux and Bluetooth 5.3. Erin’s data predicts a 5.55 score with a subwoofer, low 0.091 on-axis roughness and useful 62Hz in-room extension.
Cons: The response rises about +0.48dB per octave and narrows vertically, while directivity-index consistency is a mediocre 3.84. Its 0.232 sound-power smoothness suggests some room-response unevenness, and low bass still benefits from a subwoofer.
Full Onkyo GX-30ARC review and specifications →
| Country | Japan (design) |
|---|---|
| Dimensions | approx. 8.7H x 5.8W x 7.9D in each |
| Drivers | 1" tweeter, 4" woofer |
| Enclosure | 2-way powered, rear-ported |
| Inputs | HDMI ARC, USB-C, optical, phono/line, 3.5mm aux, Bluetooth 5.3 |
| Outputs | Subwoofer |
| Power Output | Class D amplification |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Onkyo GX-30ARC vs Edifier R1280DB
- Onkyo GX-30ARC vs KRK Classic 5
- Onkyo GX-30ARC vs Edifier S2000MKIII
- Onkyo GX-30ARC vs KEF LSX II LT
- Onkyo GX-30ARC vs IK Multimedia iLoud MTM MKII
- Onkyo GX-30ARC vs Kali Audio IN-5
- Onkyo GX-30ARC vs Yamaha HS5
- Onkyo GX-30ARC vs Adam Audio T5V
- See all 10 comparisons