Hartke HD508 4x8 HyDrive Bass Combo Amplifier

Four HyDrive speakers. Powerful Class D amplification. One complete bass rig built for rehearsal, studio and stage.

The Hartke HD508 is a professional 4x8 bass combo amplifier designed for bassists who want powerful amplification, fast speaker response and flexible tone shaping without carrying a separate amplifier head and speaker cabinet.

At the heart of the HD508 are four 8" Hartke HyDrive paper/aluminum hybrid-cone speakers powered by an integrated Class D amplifier.

The unusual 4x8 configuration combines the quick response and articulation of smaller speakers with substantial combined cone area, giving bassists a compelling balance of punch, definition and low-frequency authority.

Add Hartke's selectable Shape circuit, 3-band EQ, XLR direct output, effects loop, Aux input, headphone output and removable casters, and the HD508 becomes a versatile all-in-one bass rig for working musicians.

How Does the Hartke HD508 Work?

Unlike a passive bass cabinet, the HD508 already contains both the amplifier and speakers.

That means you don't need a separate bass amplifier head to power it.

Simply connect your bass to the HD508.

The built-in amplifier increases the power of the instrument signal.

Use the EQ and Shape controls to dial in your sound.

The four HyDrive speakers then reproduce the amplified bass signal.

Your basic setup becomes:

Bass Guitar → Hartke HD508

For live performance, the XLR direct output can also send a signal to a compatible mixing console or PA system.

Four 8" HyDrive Speakers

One of the most distinctive features of the HD508 is its four-speaker 4x8 configuration.

Rather than relying on one large driver, Hartke uses four individual 8" HyDrive speakers.

Smaller drivers can respond quickly to changes in the bass signal, helping preserve attack and articulation.

Using four of them creates substantial combined cone area.

The result is a speaker configuration designed to deliver:

• Fast transient response

• Defined bass notes

• Clear articulation

• Strong midrange presence

• Substantial combined speaker area

• Excellent response for modern bass techniques

It's a particularly interesting configuration for players who want something different from the traditional 1x15 or 2x10 bass combo.

What Is Hartke HyDrive Technology?

Hartke's HyDrive speaker technology combines paper and aluminum elements within the speaker cone.

Why use both?

Because each material contributes different characteristics.

The paper portion contributes warmth and roundness.

The aluminum portion contributes attack, punch and definition.

Together, the hybrid architecture is designed to give bassists a balanced response that retains both musical warmth and clarity.

That makes the HD508 suitable for a wide range of playing styles rather than forcing the amplifier into one particular tonal personality.

Class D Amplification

The HD508 uses Class D amplifier technology.

Class D amplification allows substantial power to be incorporated into a relatively compact and portable amplifier design.

Hartke identifies the HD508 as a 500-watt bass combo, with its detailed specifications listing:

500 watts peak / 250 watts RMS

That distinction is worth understanding when comparing amplifiers.

Peak power represents short-duration maximum capability, while RMS describes continuous rated output.

Shape Your Sound

The HD508 includes Hartke's selectable Shape circuit.

Engage Shape and the amplifier applies a specialized EQ contour.

Then use the variable Shape control to move the center of that contour through approximately 100 Hz–900 Hz.

This allows you to quickly change the overall personality of your bass tone.

Want a different midrange character?

Move the Shape control.

Need the bass to sit differently in a dense band mix?

Experiment with the contour.

Want to return to a more conventional EQ response?

Disengage the Shape circuit.

3-Band EQ

The HD508 also provides traditional Bass, Mid and Treble controls.

The EQ centers are approximately:

Bass: 70 Hz
Mid: 700 Hz
Treble: 5 kHz

Use the Bass control to adjust low-frequency weight.

Use Mid to change the instrument's presence and character within the mix.

Use Treble to control attack and upper-frequency definition.

Then combine the traditional EQ with the Shape circuit for even greater tonal flexibility.

XLR Direct Output

The HD508 includes an XLR direct output for integration with compatible professional audio systems.

This is particularly useful for live performance.

Use the HD508 as your onstage bass amplifier while simultaneously sending a direct signal to the venue's mixing console.

That gives you your own stage sound while allowing the front-of-house engineer to incorporate the bass into the main PA system.

The direct output can also be useful in compatible studio and recording environments.

Effects Loop

An integrated effects loop allows compatible external processing equipment to be incorporated into the amplifier's signal path.

This can be useful for:

• Compressors

• Multi-effects processors

• Modulation

• Delay

• Preamps

• Other compatible bass processing

The effects loop gives players another routing option beyond placing every effect directly between the instrument and amplifier input.

Auxiliary Input

The HD508 includes a 1/8" stereo auxiliary input.

Connect a compatible playback source and practice along with:

• Backing tracks

• Drum tracks

• Songs

• Lesson material

• Reference recordings

This makes the HD508 useful for personal practice in addition to rehearsal and performance.

Headphone Output

A 1/4" headphone output provides another useful practice option.

Connect compatible headphones when you need to practice without relying on the amplifier's speakers.

That means the same amplifier capable of handling rehearsals and performances can also become part of a quieter home-practice setup.

One Complete Bass Rig

One of the biggest advantages of a bass combo is simplicity.

A traditional professional bass rig might require:

Bass Head + Speaker Cabinet + Speaker Cable

With the HD508, the amplifier and speaker system are already integrated.

Your basic setup becomes:

Bass + Instrument Cable + HD508

For working musicians, fewer separate pieces of equipment can mean faster setup, easier transportation and less equipment to keep track of.

Approximately 49 Pounds

Despite combining an amplifier and four HyDrive speakers in one enclosure, the HD508 weighs approximately:

49 lb / 22.2 kg

That's the entire bass rig—not just the speaker cabinet.

For musicians who regularly move equipment between home, rehearsal, studio and stage, portability can be nearly as important as tone.

Removable Casters

Hartke includes four removable casters with the HD508.

Roll the amplifier through suitable venues, rehearsal facilities and studios instead of carrying it every step of the way.

When your setup requires the amplifier to sit directly on the floor, the casters can be removed.

For working musicians and backline crews, this is a genuinely useful feature.

Multiple Carrying Options

The HD508 includes several ways to handle the amplifier during transportation.

These include:

• Molded strap carry handle

• Two metal side handles

• Four removable casters

That gives musicians different options depending on whether they're rolling, carrying or loading the amplifier.

Perforated Steel Grille

The four HyDrive speakers are protected by a perforated steel grille.

For equipment regularly moving between stages, rehearsal rooms, vehicles and studios, protecting the speaker drivers from accidental contact is an important part of the enclosure design.

Great for Fingerstyle Bass

The HD508's combination of four smaller drivers and flexible EQ makes it a strong platform for fingerstyle playing.

Dial in a warm, full response for traditional bass lines or increase articulation when the arrangement requires the bass to remain clearly defined.

Great for Slap Bass

Slap and percussive bass techniques benefit from fast response and upper-frequency definition.

The four 8" HyDrive speakers can help reproduce the attack of slap techniques while the EQ and Shape circuit allow further tonal adjustment.

Great for Pick Playing

Rock and alternative bassists often need the instrument to maintain definition against distorted guitars.

Use the Mid, Treble and Shape controls to help the attack of the bass remain present in a dense arrangement.

Excellent for Effects-Based Bass

Modern bass rigs often incorporate:

• Compression

• Overdrive

• Distortion

• Octave

• Chorus

• Synth effects

• Delay

• Multi-effects processors

The HD508's effects loop and broad tonal response make it a useful amplification platform for more elaborate bass setups.

Rehearsal, Studio & Stage

The HD508 isn't limited to one environment.

Rehearsal

Four HyDrive speakers and powerful amplification provide a serious platform for full-band practice.

Recording

Use the amplifier's speaker sound, XLR direct output or an appropriate combination of recording techniques.

Live Performance

Use the HD508 as your onstage amplifier while sending its direct signal to a compatible PA system.

Practice

Connect backing tracks through the Aux input or use compatible headphones when you need a quieter setup.

One amplifier can therefore serve several different parts of a bassist's workflow.

Key Features & Specifications

Product Type: Bass combo amplifier
Series: HD Series
Model: HD508
Amplifier Type: Class D
Manufacturer Power Rating: 500 watts
Rated Output: 500W peak / 250W RMS
Speaker Configuration: 4 x 8"
Speaker Type: Hartke HyDrive paper/aluminum hybrid-cone drivers
Tone Controls: Bass, Mid, Treble
Bass EQ Center: Approx. 70 Hz
Mid EQ Center: Approx. 700 Hz
Treble EQ Center: Approx. 5 kHz
Shape Circuit: Selectable
Shape Control Range: Approx. 100 Hz–900 Hz
Instrument Input: 1/4"
Direct Output: XLR
Auxiliary Input: 1/8" stereo
Headphone Output: 1/4"
Effects Loop: Yes
Speaker Protection: Perforated steel grille
Carry Handle: Molded strap handle
Side Handles: 2 metal handles
Casters: 4 removable casters
Dimensions: Approx. 20" x 12" x 22"
Weight: Approx. 49 lb / 22.2 kg
Primary Applications: Live performance, rehearsal, recording and practice

Who Is the Hartke HD508 For?

Gigging Bassists — Get a complete amplifier and four-speaker system without carrying a separate head and cabinet.

Working Musicians — XLR direct output, effects-loop connectivity and removable casters make the HD508 especially practical for regular performances.

Rock Bassists — Four responsive speakers provide definition that can help the bass maintain its place in dense arrangements.

Funk & Slap Players — HyDrive technology and the 4x8 configuration provide a strong platform for articulate, percussive playing.

R&B, Gospel & Worship Players — Use the Shape circuit and 3-band EQ to adapt the amplifier to different instruments, rooms and musical arrangements.

Studio Musicians — Use the amplifier as a recording rig or incorporate its direct output into an appropriate studio signal chain.

Rehearsal Studios — Provide bassists with an all-in-one amplification system without maintaining separate heads and cabinets.

Players Who Want a Simpler Rig — One combo replaces the basic need for a separate amplifier head and speaker cabinet.

Frequently Asked Questions

What is the Hartke HD508?
The HD508 is a bass combo amplifier featuring four 8" Hartke HyDrive hybrid-cone speakers and integrated Class D amplification.

Does the HD508 require a separate amplifier head?
No. The amplifier is built directly into the combo.

How powerful is the Hartke HD508?
Hartke markets the HD508 as a 500-watt amplifier, while its detailed technical specification lists 500 watts peak / 250 watts RMS.

How many speakers does the HD508 have?
It contains four 8" HyDrive speakers.

What is HyDrive technology?
HyDrive combines paper and aluminum elements within the speaker cone to balance warmth and roundness with attack, punch and definition.

Why does the HD508 use four 8" speakers?
The four smaller drivers provide fast response while creating substantial combined cone area, giving bassists a distinctive alternative to conventional 1x15 and 2x10 configurations.

What does the Shape control do?
The selectable Shape circuit applies an EQ contour, while the variable Shape control changes the center of that contour through approximately 100 Hz–900 Hz.

Does the HD508 have an XLR output?
Yes. An XLR direct output allows the amplifier to connect to compatible professional mixing and recording equipment.

Can I connect bass effects?
Yes. The HD508 includes an effects loop for compatible external processing equipment.

Can I play backing tracks through it?
Yes. A 1/8" stereo auxiliary input accepts compatible playback sources.

Can I practice with headphones?
Yes. The amplifier includes a 1/4" headphone output.

Does the Hartke HD508 have wheels?
Yes. Four removable casters are included.

How much does the HD508 weigh?
The amplifier weighs approximately 49 lb / 22.2 kg.

Is the HD508 suitable for live performance?
Yes. Its integrated amplification, four-speaker configuration, XLR direct output, tone controls and portable design make it suitable for rehearsal and live-performance applications.

Four HyDrive Speakers. One Complete Bass Rig.

The Hartke HD508 combines four responsive 8" HyDrive speakers, Class D amplification, flexible EQ, a selectable Shape circuit and professional connectivity in one versatile bass combo.

Plug in your bass.

Shape your sound.

Add your effects.

Send a direct signal to the PA.

Play the show.

Then roll the entire rig out on its included casters.

No separate amplifier head.

No separate speaker cabinet.

No unnecessarily complicated setup.

For bassists who want an all-in-one amplifier with the distinctive response of four HyDrive speakers, the HD508 provides a versatile solution for practice, rehearsal, recording and live performance.

Need help completing your bass rig?
Backline Music Gear can help identify compatible basses, instrument cables, effects, pedalboards, wireless systems, headphones and other accessories based on your playing style and performance setup.

Hartke, HyDrive, HD508 and related names are trademarks or property of their respective owners. Product and trademark names are used solely for accurate product identification. Specifications and included components are subject to manufacturer changes. Always follow current manufacturer operating and connection instructions.