Hartke HD508 Baskombination

Hartke HD508 Bass Combo Amplifier — Four HyDrive Speakers, 500 Watts of Class D Power

The Hartke HD508 is a 500-watt Class D bass combo amplifier loaded with four patented 8" HyDrive paper/aluminum hybrid cone drivers. By packing four 8" speakers into one cabinet, Hartke has engineered a combined cone area that is larger — and reproduces a wider audio range — than a conventional single 15" driver. For bassists, this means the kind of bottom-end presence you'd expect from a much bigger rig, but with the tighter transient response that smaller cones deliver.

HyDrive Hybrid Speakers — The Core of the HD508's Voice

HyDrive speakers are the defining technology of this model. The outer cone is paper, providing the warm, rounded tone that classic bass cabinets are built on. Aluminum fills the center of the cone, adding the trademark Hartke clarity that cuts through on stage. Packing four of those drivers into a single 4 x 8" arrangement creates a rig that reviewers describe as "punchier and tighter at higher volume," because the 500 watts of available power are spread across four voice coils instead of one.

Power Section — Lightweight Class D With Real Headroom

The HD508 runs a 500-watt peak / 250-watt RMS Class D amplifier that keeps total weight down without sacrificing headroom. That power arrives at the drivers at 37.1 Vrms, with a rated input level of 77.46 mVrms at 1 kHz. Total harmonic distortion sits at 0.54% at 1 dB below rated output — numbers that show Hartke tuned the amp for clean, full-range performance rather than pure loudness.

• Rated Output Power: 500 W peak / 250 W RMS — fills rehearsal rooms and small-to-medium venues without strain
• Built around Class D with internal fan cooling, the amplifier section stays efficient and lightweight for a combo of this size.
• THD: 0.54% @ 1 dB below rated output, 1 kHz — clean signal path even when pushed

EQ and Shape Control — Tone Tools for Stage and Studio

A 3-band EQ handles the main shaping, with the bass control centered at 70 Hz, the midrange at 700 Hz, and the treble at 5 kHz. Sitting alongside it, Hartke's Shape knob adds a variable filter that sweeps between 100 Hz and 900 Hz — players can hit the in/out button to drop in a contour boost mid-song without touching their EQ settings. Reviews of the unit note that the midrange control's broad response is a real asset for staying audible over a drummer.

• 3-Band EQ Centers: 70 Hz / 700 Hz / 5 kHz — fast, musical tone shaping
• With a variable filter sweeping from 100 Hz – 900 Hz, the Shape knob gives bass-heavy sections a one-knob boost without touching your EQ.
• Signal-to-Noise Ratio: 49.3 dBu @ 1 W RMS, 1 kHz — quiet operation in studio settings

Connectivity, Cabinet, and Portability — Ready for the Gig

Inputs cover everything a working bassist needs: a 1/4" instrument input, a 1/8" stereo aux input for jamming along with backing tracks, and a 1/4" headphone output for silent practice. Outputs include a balanced XLR direct out at 4.2 Vrms for the front-of-house mix, plus a 1/4" effects send/return loop for outboard processing. The cabinet itself is built from 5/8" plywood with a perforated metal grille and four removable casters, with a steel-reinforced molded strap handle plus two inset metal side handles.

• Cabinet Dimensions: 506 mm x 305 mm x 560 mm — fits comfortably in a backline
• At 22.2 kg with removable casters attached, the enclosure is road-friendly for the rated power output.
• I/O: 1/4" instrument in, 1/8" aux in, 1/4" headphone out, XLR DI out, effects loop — covers practice, stage, and recording chains

Who the HD508 Is Built For

Gigging bassists needing a self-contained combo for rehearsals, mid-sized club venues, and studio sessions — without the weight penalty of a 2x10 or 1x15 rig — will find the HD508 the right fit. Intermediate players moving up from a practice combo will appreciate the headroom and the EFX loop, while working players benefit from the XLR direct output and the rugged 5/8" plywood cabinet. It's also a strong fit for 5-string players running low B, where the four-driver cone area gives the low-end clarity a single-driver combo struggles to reproduce.

Hartke HyDrive History and the HD508's Place in the Lineup

Hartke introduced the HyDrive hybrid paper/aluminum cone technology as a way to combine the warmth of a traditional paper driver with the cutting character that Hartke aluminum-cone speakers have been known for since the 1980s. The HD508 sits at the top of the HD Series combos, with the smaller HD50 (10"), HD75 (12"), HD150 (15"), and HD500 (2x10") sharing the same control layout and Shape circuit philosophy. Bassist Victor Wooten has demonstrated the HD508 for the brand, highlighting the four-driver voicing and the variable Shape filter as the standout features for live performance.