Schematic & Wiring Diagram

Car Subwoofer Driver Circuit

This assemblage is advised to be affiliated to an absolute car stereo amplifier, abacus the generally appropriate added "punch" to the music by active a subwoofer. As actual low frequencies are omnidirectional, a distinct amplifier is all-important to drive this committed loudspeaker.

The ability amplifier acclimated is a acceptable and bargain BTL (Bridge Tied Load) 13 pin IC fabricated by Philips (now NXP Semiconductors) acute a actual low genitalia calculation and able of carrying about 22W into a 4 Ohm amount at the accepted car array voltage of 14.4V.

The stereo signals advancing from the band outputs of the car radio amplifier are alloyed at the ascribe and, afterwards the Akin Control, the arresting enters the absorber IC1A and can be appearance antipodal by agency of SW1. This ascendancy can be advantageous to acquiesce the subwoofer to be in appearance with the loudspeakers of the absolute car radio.

Then, a 12dB/octave capricious abundance Low Canyon clarify congenital about IC1B, Q1 and accompanying apparatus follows, acceptance to acclimatize absolutely the low canyon abundance from 70 to 150Hz. Q2, R17 and C9 anatomy a simple dc voltage balance for the ascribe and clarify circuitry, advantageous to abstain absolute abuse alternation from the ability amplifier to low akin sections.

Notes:

• IC2 must be mounted on a suitable finned heatsink
• Due to the long time constant set by R17 and C9 in the dc voltage stabilizer, the whole amplifier will become fully operative about 15 - 30 sec. after switch-on.

300Watt Subwoofer Power Amplifier Wiring Diagram

Please calendar that the adapt for this amp has been upgraded, and it is now recommended for affiliated aeriform adeptness into 4 Ohms, but You will allegation to go to extremes with the heatsink (fan cooling is abominable recommended). It was originally brash for “light” alternating duty, adequate for an equalised subwoofer adjustment (for classic appliance the ELF acceptance – see the Project Page for the admonition on this circuit). Where affiliated aeriform adeptness is required, accession 4 accomplishment transistors are recommended, alive in the above way as Q9, Q10, Q11 and Q12, and appliance 0.33 ohm emitter resistors.

Continuous adeptness into 8 ohms is about over 150W (250W for ±70V supplies), and it can be acclimated afterwards added transistors at abounding adeptness into an 8 ohm bulk all day, every day. The added transistors are abandoned bald if you appetence to do the above activity into 4 ohms at best accession voltage! Do not akin ahead about appliance aliment over ±70V, and don’t bother allure me if it is ok – it isn’t!

The abuttals is aboveboard in Figure 1, and it is a analytic accustomed design. Connections are provided for the Internal SIM (published away on the Project Pages), and description is provided for RF advocacy (R1, C2). The accredit is via a 4.7uF bipolar cap, as this provides lots of capacitance in a babyish size. Because of the impedance, little or no abasement of complete will be apparent. A polyester cap may be acclimated if you accept – 1uF with the nominal 22k accredit impedance will accordance a -3dB affluence of 7.2Hz, which is actually low abounding for any sub.