We first saw the JBL Synthesis SMA Series Amplifiers at the Harman Luxury Audio Group exhibit at the 2024 CEDIA Expo, but at that time it was indicated that they would be released in 2025. Since they have been released in select overseas markets, but are now available for North American consumers.
The SMA Series amplifiers are designed for residential custom installation customers.
The SMA-4750 and SMA-8300 are Class D multichannel DSP amplifiers designed to deliver high-power output and accommodate multi-channel and multi-room systems. With advanced features like bridgeable channels, full input and output Hi-Resolution DSP, and DANTE / AES67 digital audio networking, these amplifiers are intended to be go-to options for powering large LCR, surround, and height channel loudspeakers, as well as subwoofers in JBL Synthesis immersive audio systems.
Both models feature a compact, stackable design with quiet side-to-side ventilation. The comprehensive DSP platform offers EQ, Delay, and Limiters. This provides installers and users with lots of installation and audio setup flexibility.
Each model also has a front panel user interface/status display that provides a simplified control option if desired.
SMA-4750: This is a 4-channel amplifier that provides 750W per channel at 8 ohms, with the capability to bridge adjacent channels to provide up to 1,800W at 8 ohms.
SMA-8300: This is an 8-channel amplifier that provides 300W per channel at 8 ohms, with bridging options that allow up to 1,200W per channel at 8 ohms. The SMA-8300 is designed for more expansive systems, supporting a wider range of speaker setups than the SMA-4750.
Comparison
| SMA-4750 | SMA-8300 | |
| Product Type | 4-channel Bridgeable Class D Amplifier | 8-channel Bridgeable Class D Amplifier |
| Price | $5,000 | $6,000 |
| Inputs | Analog audio input Digital audio input (Dante/AES67) 2x RJ45 | 8x XLR (Balanced) Digital audio input (Dante/AES67) 2x RJ45 |
| Output | Binding Posts, accommodates 10AWG wire, spade, and banana termination | Binding Posts, accommodates 10AWG wire, spade, and banana termination |
| 12 Volt Trigger | 1x 3.5mm (in) 1x 3.5mm (out) | 1x 3.5mm (in) 1x 3.5mm (out) |
| Network/Monitoring Control | 1x RJ45 | 1x RJ45 |
| Power | Standard IEC | Standard IEC |
| Power Output (2 channels driven, <0.5% THD) | (8Ω) 750W (4Ω) 1,500W (8Ω Bridged, one zone driven) 2,500W | (8Ω) 300W (4Ω) 600W (8Ω Bridged, one zone driven) 1,200W |
| Digital Signal Processing | 96kHz, 32-bit floating point | 96kHz, 32-bit floating point |
| Frequency response (+-0/5 dB) | (4Ω) 20Hz – 20kHz | (4Ω) 20Hz – 20kHz |
| Total Harmonic Distortion (THD) (at full rated power, from 20Hz – 20kHz) | 0.35% | 0.35% |
| Analog Input SNR Signal-to-Noise-Ratio (ref. Rated power, ‘a’-wtd.) | >105dB | >105dB |
| Analog Input SNR Signal-To-Noise Ratio (ref. Rated power, 20Hz – 20kHz) | >99dB | >99dB |
| Damping Factor (20Hz to 100Hz) | >1000 | >1000 |
| Input Impedance (nominally balanced, nominally unbalanced) | 70 kΩ balanced, 35 kΩ unblanced | 70 kΩ balanced, 35 kΩ unblanced |
| Maximum input level (low amp gain mode) | +21dBU | +21dBU |
| Load impedance (Stereo/Dual Mode) | 2Ω –16Ω load | 2Ω –16Ω load |
| Impedance (Bridged Mono) | 4Ω – 16Ω | 4Ω – 16Ω |
| Maximum fan noise (REF. dB SPL @ 1M) | 51dBA | 51dBA |
| Power supply | 100 – 220V ±10%, 50/60Hz | 100 – 220V ±10%, 50/60Hz |
| Dimensions incl. rack ears, connectors, controls (HWD) | 3.5 x 19.0 x 17.0 in 88.9 x 482.6 x 432.6 mm | 3.5 x 19.0 x 17.0 in 88.9 x 482.6 x 432.6 mm |
| Net Weight | 21.8 lb (9.9 kg) | 23.1 lb (10.5 kg) |
| In The Box | 1x JBL Synthesis SMA-4750 1x Quick-start guide and safety sheet Rackmount brackets and fastening screws AC Power Cord(s) – quantity and type vary by region | 1x JBL Synthesis SMA-8300 1x Quick-start guide and safety sheet Rackmount brackets and fastening screws AC Power Cord(s) – quantity and type vary by region |
From Jim Garrett, Senior Director, Product Strategy and Planning, HARMAN Luxury Audio: “Designed to elevate home cinema experiences, the new JBL Synthesis SMA Series amplifiers set a new benchmark for power, flexibility, and performance,…These amplifiers are designed to deliver exceptional power and audio fidelity, making them a perfect fit for any high-end home audio system. They embody our commitment to innovation and home cinema audio expertise.”
The Bottom Line
The CI category really took off during the COVID pandemic for the simple reason that consumers had no live music options and movie theaters were shuttered across North America. Home theaters exploded in popularity and consumers with larger budgets began experimenting with multi-room audio systems throughout their homes and even outdoors.
That level of expansion requires more channels of amplification and music listeners and home theater fans who opted for JBL Synthesis loudspeakers are probably looking to improve on what they already have.
The JBL SMA Series amplifiers are designed to provide a flexible option, especially when paired with JBL Synthesis SCL series speakers and SSW series subwoofers.
Price and Availability
The JBL Synthesis SMA-4750 and SMA-8300 are priced at $5,000 and $6.000 respectively and are available through Authorized Dealers.
Related Reading
- Keeping it Simple with the Naim CI-Uniti 102 Streaming Amplifier
- DALI Phantom M-80 A In-Ceiling Speaker and CI AMP-4750 DSP Unveiled at ISE 2025
- WiiM for Custom Installations? Check out the CI MOD S Streamer and A80 Streaming Amplifier
- Monitor Audio’s Custom Installation Amplifier 2G Series Adds 4 New Models
