DAC to boost 2019 iMac audio out

Hardware
,
1

I have 2 Edifier monitor speakers connected to my 2019 iMac 27" through the headphone out jack. The audio volume is very low and I have to turn the audio up almost to max to hear them well.

I recently connected my Windows PC to them, also using stereo out, and almost blew my speakers. I turned the volume way down on the sparks. I was able to listen to music comfortably with 1/2 master volume and 1/2 iTunes for Windows volume.

I plugged my iMac back in and I couldn’t hear anything at normal volume levels. It was barely audible at high master and iTunes levels. I had to jack the volume up on the speakers again to make audio from my iMac audible.

These tests lead me to conclude that speaker audio out signal on my iMac is extraordinarily weak, I am wondering if I should get a USB DAC or similar audio device to provide a stronger input signal to my Edifier speakers. They only accept RCA audio in so I can’t connect them directly to the iMac via USB.

Edited to provide Additional Info:

  • The speakers have volume adjustments.
  • The speakers are wall mounted up high enough that I need a step stool to reach them to adjust the volume.
  • My goal is no have to jack the volume on the speakers too high. When I do that , they make a loud popping noise every few minutes when the iMac goes to sleep until I turn them off.
  • I have not contacted Apple Support. I suspect their response will be “contact us when you have a real problem.”
2

Take a look at the Audioquest Dragonfly lineup.

1 Like
3

As the speakers have RCA in, they would be powered and have a built-in amp. That usually means you have a volume control button on the speaker itself, but this seems unlikely you have overlooked. However, the headphone out is variable power, while the PCs Stereo Out would be fixed at 2 volts.

In general, the Line-level signal should be at 2 volts out of the Mac into whatever amp drives the speakers. This is generally set by max volume on the Headphone Master and you then control volume in iTunes or other players. For the Dragonfly Red and Cobalt, the max output is 2.1 v so keep these at around 90% to avoid distortion.

That said, you SHOULD be able to get a proper Line-out signal from your Mac already, without additional purchases. Moving to an external DAC would most likely improve the quality of the sound, though.

1 Like
4

Re-reading your post again, I think you say that you actually have a volume control on the speakers. This is good news :slight_smile: Set headphone out to 100%, and use the volume control on the speaker to control the volume using the internal amp. This gets you a proper signal in. Lower levels on Headphone Out will require the amp to work at higher power, resulting in reduced audio quality and increased noise in the signal.

1 Like
5

Higher gain, rather than higher power. The signal to noise ratio is lower, meaning more noise will be heard when the volume is high enough to discern the signal.

Agreed. This shouldn’t be an issue, and you shouldn’t have to buy a DAC to make your $2000 computer work. If the iMac will drive headphones (this would be something to test), it should easily provide enough signal for amplified speakers.

Have you tried contacting Apple support?

1 Like
6

Ah, thanks @JohnAtl, that is the correct term that was escaping me earlier.

1 Like