Skip Navigation

Helix Blue B FOUR

4-channel car amplifier — 60 watts RMS x 4

3 Reviews | 1 question - 1 answer

Item # 975BFOUR

This item is no longer available.

Shop all Car Amplifiers

Overview

Our take on the Helix Blue B FOUR

German engineering and craftsmanship combine to create a sleek amplifier that'll make your vehicle come alive with crystal-clear, powerful music. The Helix Blue B FOUR 4-channel amplifier puts out 60 watts RMS each to your full-range speakers, both front and rear. Or, you can use the B FOUR in 2-channel mode to power a couple of subwoofers with up to 180 watts RMS each.

Clean lines and solid power

German engineering and craftsmanship combine to create a sleek amplifier that'll make your vehicle come alive with crystal-clear, powerful music. The Helix Blue B FOUR 4-channel amplifier puts out 60 watts RMS each to your full-range speakers, both front and rear. Or, you can use the B FOUR in 2-channel mode to power a couple of subwoofers with up to 180 watts RMS each.

Made for high quality sound

The Helix Blue B FOUR amp starts with a noise-free input stage, then uses proprietary technology to achieve an incredible level of acoustic accuracy. The attention to detail extends down to the superior internal components, specially "surface-mounted" to double-sided, copper-plated circuit boards, all contributing to superb sound quality. A big, heavy wrap-around heatsink dissipates the heat for cool, reliable play.

B FOUR features

You'll find the tools you need to shape your sound. The wide range of the high- and low-pass filters allows you to adjust for the best possible performance from different types of speakers. A bass boost will add even more bang, if you want it to.

Amp for a Helix factory upgrade system

The B FOUR can also serve as an amp in a Helix Plug and Play factory upgrade system. You can use an EPC5 Easy Plug Cable and a Helix vehicle-specific adapter harness to plug your B FOUR directly into your vehicle's stereo to get its input signal, with no wire-cutting or splicing necessary.

Great amp! It really is very quiet -- I get no alternator noise through this amp at all. I love the fact that this amp is German made and engineered.

JJ, New Jersey

What's in the Box:

  • Four-channel amplifier
  • Two 25 amp ATO fuses (installed)
  • Four 3/4" Self-tapping screws
  • 8" Speaker-level input harness (Molex plug on one end)
  • 4mm Allen wrench
  • 2mm Allen wrench
  • Instruction manual (German/ English)

Product Highlights:

  • 4-channel car amplifier
  • 60 watts RMS x 4 at 4 ohms (90 watts x 4 at 2 ohms)
  • 180 watts RMS x 2 bridged output at 4 ohms (4-ohm stable in bridged mode)
  • Class A/B design
  • variable low-pass filter (15-4000 Hz)
  • variable high-pass filter (40-4000 Hz)
  • bass boost (0-18 dB at 45 Hz )
  • speaker-level inputs via 8-pin harness
  • preamp inputs and outputs
  • 8-gauge power and ground leads recommended — wiring and hardware not included with amplifier
  • fuse rating: 25A x 2
  • 14-1/4"W x 2"H x 10-1/4"D
  • warranty: 2 years
  • Our 60-day money-back guarantee
Reviews

Helix Blue B FOUR Reviews

Average Customer Review(s):

(3 Reviews)
rewards card

Submit a review and enter to win a $350 rewards card

Review this product

Thanks for submitting your review

Most reviews are processed and published within 5 business days. You will receive a confirmation email once your review has been published.

Your Review

Use the stars below to rate the overall product on a scale of 1-5
1500
Upload your photos

Not visible. Email associated with order.
(e.g., Charlottesville, VA)

Additional Fields (optional)

500
500

By submitting this review, you agree to our terms and review guidelines.

Filter by rating

Customer photos


<< >>
Details

Hands-on research

Product Research

Features
Controls
Connections

Features

2-Ohm Stable: In stereo mode (powering four speakers) the amplifier is stable down to 2-ohms. The 2-ohm output is 90 Watts RMS x 4 channels.

Bridgeable: The B FOUR can be bridged to two channels, outputting 180 Watts x 2-channels into 4 ohms. You can also wire the B FOUR in three channel mode, bridging half the amp and running the other half in stereo (60 Watts RMS x 2 channels plus 180 Watts x 1-channel).

Protection Circuitry: The B FOUR offers four protection circuits: short circuit (or too low an impedance on the outputs), thermal overload, over voltage, and under voltage.

Controls

4-Channel: The amplifier is divided into two sections, channels 1/2 and channels 3/4. Each pair of channels has independent gain, bass boost, and crossover controls.

Crossover: The built-in crossovers have three position switches to select the crossover operation as high-pass, full-range, or low-pass. The high-pass crossover points are continuously variable from 15 Hz to 4 kHz. The low-pass crossover points are continuously variable from 40 Hz to 4 kHz.

Note: When a crossover switch is in the low-pass position, the high-pass frequency dial is also active. Depending on the high-pass frequency setting, this creates either a subsonic filter (useful for any subwoofer and often necessary for ported enclosures) or a band-pass crossover (with a lower limit from 15 Hz to 4 kHz, and an upper limit from 40 Hz to 4 kHz).

Gain: The rotary gain controls are continuously variable from 0.2 volts to 6.0 volts to match the source signal.

Bass Boost: The bass boost circuits are centered at 45 Hz and continuously variable from 0 dB to +18 dB.

Connections

Power: The power and ground inputs are set-screw terminals; they will accept bare wire up to 4-gauge (HELIX recommends 8-gauge minimum) and are tightened/loosened with the supplied 4mm Allen wrench.

Remote: The remote turn-on input is a set screw terminal; it will accept bare wire up to 10-gauge and is tightened/loosened with the supplied 2mm Allen wrench.

Speaker Outputs: The speakers connect to four pair of set-screw terminals; they accept bare wire up to 10-gauge and are tightened/loosened with the supplied 2mm Allen wrench.

Line Input: Two pair of stereo RCA jacks connect to the output signal from the head unit.

Speaker Level Input: Use the included harness when speaker level inputs are needed, or use the HELIX Easy Plug Cable and vehicle specific adapter harness (both sold separately, see explanation above).

Note: The included speaker level input harness doesn't use the standard aftermarket color codes, and there's no color key in the manual (although the pin positions are labeled on the side of the amp). The colors used are:
  • Black: channel 1 negative
  • Yellow: channel 1 positive
  • Gray: channel 2 negative
  • Red: channel 2 positive
  • White: channel 3 negative
  • Blue: channel 3 positive
  • Green: channel 4 negative
  • Orange: channel 4 positive

Line Output: Stereo RCA output jacks make adding another amplifier easy. The settings on the built-in crossovers have no effect on the line outputs.

Fuse: The amp is protected by two 25-amp ATO-type fuses.

Our Product Research Team

At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team. They verify what’s in the box, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.

Accessories
Q & A

Customer Q&A

1 question already asked

The amp is made in Germany [ HAMID  Nov 16, 2014 ]
Articles