AppleDesign Powered Speakers

AppleDesign Powered Speakers
The original AppleDesign Powered Speakers (M6082): satellite speaker on the left, main speaker with the controls on the right
Manufacturer	Apple Computer, Inc.
Type	Powered stereo speakers
Release date	1993 (original); 1994 (II)
Price	US$179 (Apple Catalog, Fall 1993)
Interface	3.5 mm stereo computer input; CD input (dual RCA on the original, 3.5 mm on the II); 3.5 mm headphone output
Compatible	Any Macintosh or other computer with sound output; CD players, cassette players, televisions
Dimensions	231 × 112 × 119 mm (original); 175 × 107 × 101 mm (II)
Model	M6082 (original)
Power	External power-supply module: 15 V DC, 40 W maximum (original); 12 V DC, 24 W maximum (II)
Part number	M4475LL/A (original); M3261LL/A slate and M2668LL/A platinum (II)

The AppleDesign Powered Speakers are a pair of amplified desktop speakers that Apple Computer sold from 1993 for the Macintosh and other computers. The main speaker holds a two-channel amplifier, the controls and the inputs, and drives a passive satellite speaker over a two-wire cable. Both speakers are magnetically shielded so they can sit beside a monitor. Apple added the smaller AppleDesign Powered Speakers II in late 1994, and both models were still in Apple Facts in November 1996. One Service Source covers both models.

History

Apple's Tech Info Library description of the speakers is dated 15 March 1993, and Apple's New Product Information disc for March 1993 covered them. The Apple Catalog for Fall 1993 sold them for US$179, catalogue code E1503, and suggested connecting Apple's PowerCD player to them for audio CDs.

A later revision of the main speaker added a subwoofer output. Apple's specification article marks the subwoofer jack "only available on the Rev B model", and the Service Source lists the main speaker without the jack, 661-1689, as replaced by 661-1737, the main speaker with the subwoofer jack. Apple did not sell a subwoofer to go with it; its 1996 note on the jack refers the owner to the manual of a third-party subwoofer.

AppleDesign Powered Speakers II

AppleDesign Powered Speakers II in platinum, main speaker on the left (photo: Stephen Edmonds, CC BY-SA 2.5)

The AppleDesign Powered Speakers II are shorter, with a curved cabinet, and came in two colours: slate (M3261LL/A) and platinum (M2668LL/A). The speaker-to-speaker cable is attached to the satellite and ends in a miniplug. The II has a volume control and headphone socket on the front of the main speaker, but no balance control and no power switch. Both inputs on the II are 3.5 mm stereo jacks, one marked for the computer and one for a CD player, and the II has no noise gate. Apple serviced the II by exchanging the whole set, under part numbers 661-0048 (platinum), B661-0048 (British) and Z661-0048 (international), each supplied with its cables and adapter.

Specifications

AppleDesign Powered Speakers specifications

Item	AppleDesign Powered Speakers	AppleDesign Powered Speakers II
Speaker type	Full range, tuned port, bass reflex
Maximum output	90 dB SPL at 0.5 m at 90 Hz	90 dB SPL at 0.5 m at 200 Hz
Frequency response	90 Hz to 17 kHz (±3 dB)	150 Hz to 20 kHz
Amplifier	Two channels, Class B	Two channels, 14 W
Maximum input	2 V peak to peak
DC supply	15 V DC	12 V DC
Mains input	100 to 240 V AC, 50 to 60 Hz, depending on the power-supply module; 40 W maximum	100 to 240 V AC, 50 or 60 Hz, depending on the module; 24 W maximum
Size (H × W × D)	23.1 × 11.2 × 11.9 cm	17.5 × 10.7 × 10.1 cm
Weight	2.2 kg (4.8 lb) for the pair	612 g (1.34 lb) in the Service Source; 1.2 kg (2.7 lb) for the pair in Apple Facts

Apple's figures differ between documents. Apple Facts gives the original as 23.5 × 11.4 × 12.1 cm, where the Service Source has 23.1 × 11.2 × 11.9 cm. The Service Source prints the 40 W maximum power and the 15 V supply once for both models; the II's own specification article gives 24 W and 12 V.

Connections

Rear panel of an original main speaker, model M6082: speaker-wire terminals at the top; computer input, a jack marked with a loudspeaker symbol, CD RCA inputs and the 15 V DC input at the bottom (photo: Gona.eu, CC BY-SA 3.0)

The original speakers have four connections on the main unit:

• the computer input, a 3.5 mm stereo jack wired sleeve ground, ring right, tip left
• the CD input, a pair of RCA jacks
• the speaker-to-speaker terminals, spring-clip ("pull-down") terminals that take stripped and tinned wire
• the headphone jack on the front panel, a 3.5 mm stereo jack

On the Rev B main speaker a fifth jack is the subwoofer output. The supplied cables were a computer interconnect cable with 3.5 mm plugs, a CD stereo cable and an insulated two-strand speaker cable. Fit the black wire of the speaker cable to the black terminal and the white-striped wire to the red terminal. Apple's symptom chart gives a wrongly fitted speaker cable as the cause of missing bass.

The dual-input mixer plays the computer input and the CD input together, so a CD-ROM drive's audio output and the computer's sound output can both stay connected.

Noise gate on the computer input

The original speakers have a noise gate on the 3.5 mm computer input only. It mutes the amplifier when the signal at that jack falls below a fixed level, which keeps hiss out of the speakers between system beeps. On quiet passages of an audio CD it also cuts the sound out. Apple's two remedies were to turn the Sound control panel volume up and use the speakers' own volume knob, or to feed the computer's output into the RCA CD inputs through a 3.5 mm to dual RCA Y-cable, which bypasses the gate. The II has no noise gate.

Subwoofer output

The Rev B subwoofer output can reach 2 V peak to peak. Apple's advice is to use a subwoofer that accepts that level or has an input level control, to start with both the speakers' volume and the subwoofer's input level at minimum, and to raise them slowly. According to a 68kMLA member, only this early version of the speakers has the subwoofer port; the later original-style units and the II lack it. That conflicts with the Service Source, where the main speaker with the jack (661-1737) is the later replacement for the one without (661-1689). Check the back panel of the unit in hand.

Power supply

Both models run from an external power-supply module. Apple's service part for the original was 922-1179, a 110 V AC to 15 V DC adapter, and power adapter and cable kits came for Australia (X076-0871), Britain (B076-0871), Europe (Z076-0871, 220-240 V AC to 15 V DC) and Japan (J076-0871).

Owners without the original adapter report that the original speakers' DC socket is unusual: one 68kMLA member describes a large barrel with a two-pronged positive pin, and another gives it as a 7 mm plug, 15 V at 1 A, centre positive. That member replaced the socket on the speaker's board with a 5.5 mm centre-positive socket from a scrapped router so that a common adapter would fit; a cheap 15 V adapter that measured only 7.5 V made the speakers buzz without lighting the power LED. Before connecting any substitute adapter, measure its output on load and check its polarity against the symbol printed beside the DC input.

For the II, a 68kMLA member reports a standard 12 V, 1 A, positive-polarity adapter; another found that generic 12 V adapters gave a loud hum, while a bench supply ran the speakers quietly. Because the II has no power switch, unplug the adapter when the speakers are not in use.

Troubleshooting

AppleDesign Powered Speakers symptoms

Symptom	Cause	Action
One speaker silent	Loose power cable or speaker-to-speaker cable	Reseat the power cable and the speaker-to-speaker cable at both ends
Weak sound or no sound	Computer off; loose cable; volume low at the CD-ROM drive, the main speaker or the Sound control panel; original model switched off	Check each in turn. On the original, press the power switch so that the light above it comes on
No bass (original)	Speaker-to-speaker cable reversed or loose	Black wire to the black terminal, white-striped wire to the red terminal
Sound cuts out on quiet passages (original)	Noise gate on the computer input	Raise the computer's output level and use the speaker volume knob, or feed the RCA CD inputs through a Y-cable
AM radio heard in the speakers	Speaker wires acting as an aerial	Fit better-shielded cable
Buzz, no power light (original)	Substitute adapter giving too little voltage	Measure the adapter; it must deliver 15 V
Hum (II)	Generic 12 V adapter	Use a well-filtered 12 V supply; a bench supply ran them quietly
Foam surround round the driver cone crumbled or missing	Age; the foam rots	Refoam the drivers or fit replacements of the same size

Apple's own fault-finding stops at the cables, controls and adapter. For the original speakers the service parts were the main speaker, the satellite speaker (661-1716), the power adapter and the cable kit (076-0473); for the II, the whole set. The Service Source has no schematic and no board-level parts list.

Care and restoration

The drivers in the original speakers have foam surrounds, and 68kMLA members report the foam rotted on several pairs. One member bought replacement foam surrounds and trimmed them to fit. Before refoaming, press the cone gently to check that it moves freely, since a voice coil that has corroded in storage can stick.

The metal grilles on the original speakers do not come off easily. One owner could not shift them with a heat gun, and replies suggested they are glued in. The owner retrobrited the cabinet with the grilles in place, and the metal came to no harm after several hours in the solution. Another member's experience with other machines is that metal parts start to rust as soon as they come out of the solution, so rinse and dry them at once.

Documentation

• AppleDesign Powered Speakers Service Source: Apple's Service Source for both models, with specifications, symptom charts and the parts list.

Related pages

• Apple Pro Speakers
• Apple PlainTalk Microphone