Crown CX-724: The Workhorse Equalizer of the 1990s Pro Audio Scene
Attention in vintage audio usually goes to tube amplifiers, analog mixers and classic receivers. But in countless live sound setups, recording studios and house-of-worship installations of the 1990s, the Crown CX-724 was doing the work. It is not a preamp or an amplifier. It is a 2U rackmount 24-band graphic equalizer. Crown Audio built it, the same company known for its power amplifiers and pro audio innovation, and the CX-724 shows the no-nonsense, reliability-first engineering Crown was known for.
The CX-724 came out in the mid-1990s as part of Crown's CX series of signal processors, which included equalizers, crossovers and feedback suppressors. It was designed for live sound reinforcement and system tuning. Crown never marketed it as a "hi-fi" component for home listening. Even so, its precision, build quality and clean signal path have earned it a quiet following among vintage audio enthusiasts, sound engineers and DIY audio tinkerers who like its utility and durability.
Technical Specifications
The CX-724 is a stereo 24-band graphic equalizer, offering precise control over the frequency spectrum. Each channel features 24 sliders spaced at 1/3-octave intervals, allowing for surgical adjustments to correct room acoustics, tame feedback, or tailor speaker response. It was commonly used in front of power amplifiers to fine-tune PA systems or monitor setups.
| Specification | Detail |
| Model | CX-724 |
| Manufacturer | Crown Audio (a division of Harman International) |
| Year Introduced | early 1980s (exact year unconfirmed) |
| Form Factor | 2U rackmount (19" width) |
| Channels | Stereo (2 channels) |
| Bands per Channel | 24 (1/3-octave spacing) |
| Frequency Range | 25 Hz – 16 kHz |
| Frequency Centers | Standard ISO 1/3-octave: 25, 31.5, 40, 50, 63, 80, 100, 125, 160, 200, 250, 315, 400, 500, 630, 800, 1k, 1.25k, 1.6k, 2k, 2.5k, 3.15k, 4k, 5k, 6.3k, 8k, 10k, 12.5k, 16k Hz |
| Cut/Boost Range | ±12 dB per band |
| Input Connectors | Balanced XLR and 1/4" TRS |
| Output Connectors | Balanced XLR and 1/4" TRS |
| Input Impedance | 20 kΩ balanced |
| Output Impedance | 150 Ω balanced |
| Frequency Response | 20 Hz – 20 kHz (±0.5 dB) |
| THD + Noise | < 0.02% at +20 dBu output |
| Power Supply | 100–120V or 220–240V AC (switchable), 50/60 Hz |
| Power Consumption | 30 watts |
| Dimensions (H×W×D) | 3.5" × 19" × 7.5" (89 × 483 × 190 mm) |
| Weight | 8.5 lbs (3.9 kg) |
Sound Characteristics and Performance
The Crown CX-724 is not designed to "color" the sound. It aims for transparency and control. Some vintage equalizers, such as the Pultec or early API units, impart a warm, analog character. The CX-724 aims for clinical accuracy instead. Its low distortion, wide frequency response and balanced circuitry mean it alters only what you intend, without adding artifacts.
That makes it a good tool for system correction. It can flatten the response of a room with problematic acoustics, or eliminate feedback frequencies during live performances, and it gives consistent, predictable results either way. The 1/3-octave bands give enough resolution for precise adjustments, and the ±12 dB range allows both subtle shaping and aggressive cuts.
It is not meant for musical EQ sculpting the way a parametric equalizer is, but it can be repurposed. Some studio engineers have used it for broad tonal shaping, or even as a "vibe" processor when pushed with intentional over-EQ-ing. That is far from what it was designed to do.
Notable Features and Innovations
Two things set the CX-724 apart from other graphic equalizers of its era: its ruggedness and its professional feature set.
- Dual Input/Output Options: With both XLR and 1/4" TRS jacks, the CX-724 integrates seamlessly into any professional setup, whether analog or digital.
- Balanced Signal Path: Ensures noise rejection over long cable runs—critical in live environments.
- Switchable AC Voltage: Makes it suitable for international use without external transformers.
- LED Gain Reduction Metering: While not a compressor, the CX-724 includes LED meters that show signal level per channel, helping users avoid clipping.
- Bypass Switch: A front-panel switch allows instant A/B comparison by bypassing the EQ circuit entirely—a crucial feature during system tuning.
- Detented Sliders: The sliders have a slight mechanical resistance (detents) at the 0 dB position, making it easier to return to a flat response or recall settings accurately.
Crown also fitted the CX-724 with high-quality potentiometers and a steel chassis that resists flex and protects the internal components.
Common Issues and Maintenance
Like any 30-year-old electronic gear, the Crown CX-724 can develop issues over time, though it's generally considered reliable.
- Slider Noise: The most common problem. Over time, the sliders can become scratchy due to dust or oxidation. Cleaning with contact cleaner (e.g., DeoxIT) can often restore smooth operation.
- Power Supply Failure: While robust, the internal power supply can fail, especially if the unit was frequently moved or exposed to power surges. Checking capacitors and fuses is a good first step.
- Loose Connectors: XLR and 1/4" jacks may become loose from repeated plugging. Solder joints should be inspected if signals drop intermittently.
- LED Failure: Some LEDs may dim or burn out, but replacements are standard and easy to source.
Regular cleaning, gentle handling and avoiding extreme environments will extend the life of a CX-724 significantly. In modern setups, consider pairing it with a power conditioner to protect against voltage spikes.
Current Market Value and Collectibility
The Crown CX-724 is not a "collector's item" the way a vintage McIntosh amplifier might be, but it holds steady value among working professionals and pro audio hobbyists. Units in good working condition typically sell for $150 - $250 on the used market (eBay, Reverb, etc.), depending on region and included accessories.
Its collectibility is more functional than nostalgic. Engineers restoring vintage PA systems or building analog live rigs often seek out the CX-724 for its reliability and clean performance. It's also popular in DIY audio circles, where some have repurposed it as a mastering-grade EQ or integrated it into custom studio chains.
It is not rare, but original, unmodified units with clean sliders and full functionality are becoming harder to find. That may slowly increase their value among niche enthusiasts.
Conclusion and Legacy
The Crown CX-724 lacks the glamour of a tube amplifier or the mystique of a Neve console. Live sound was evolving rapidly in this era, with larger venues and more complex systems, and tools like the CX-724 provided clarity, control and consistency.
Digital processors and software EQs have largely replaced hardware graphic equalizers in mainstream use. The CX-724 remains a capable, hands-on option for those who prefer tactile control and analog signal paths.
For vintage audio collectors, the CX-724 offers a bridge between consumer hi-fi and professional audio. It’s a reminder that great sound isn’t just about warmth or richness—it’s also about precision, reliability, and the quiet confidence that your gear will perform when it matters most.
A working Crown CX-724 can still be useful in a studio, a live rig, or even a high-end home system that needs room correction.
Similar items on eBay
No exact Crown CX-724 listings are live right now — these searches show current Crown and similar vintage audio gear on eBay:
As an eBay Partner, we earn from qualifying purchases. This helps support our independent vintage technology research.