Do I need a DAC to fix low volume stereo out on 2019 iMac?

[jagooch]

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, which I define as 50% master volume and 50% of app volume slider. 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.


Ideas?

 

[jerwin]

Have you tried plugging in a set of headphones? (normal, 32 ohm headphones, not 600 ohm exotics).

The imac's headphone jack is specced as follows

3.5 mm headphone jack
The headphone output supports a stereo data stream at bit depths of 16, 20, or 24 bits per sample and at sample rates of 44.1kHz or 48kHz. The headphone output volume can be adjusted from 0.0 dB to -43.0 dB.

During playback of a 1 kHz sine wave at -3 dBFS voltage level, 24-bit sample depth, 44.1kHz output sample rate, and 100k load (unless otherwise specified), the audio output has the following nominal specifications:

• Jack type: 3.5 mm (1/8-inch) stereo combo
• Maximum output voltage: 1.4 VRMS (+5.15dBu)
• Output impedance: <24 ohms
• Frequency response: 20 Hz to 20 kHz, +0.5dB/-3 dB
• Signal-to-noise ratio (SNR): >90 dB
• Total harmonic distortion + noise (THD+N): <-80 dB (0.007%)
• Channel separation: >85 dB

https://support.apple.com/en-us/HT204392#2017

Compare the maximum output voltage to the specs on your windows machine. Or, to any DAC under consideration.

 

[TheIntruder]

The simple question would be -- what level is your system volume level set to?

The system volume and iTunes volumes are separate levels, and factor in the speakers' own volume as a third.

BTW, which Edifiers, and do you like them?

 

[jerwin]

Some of the Edifier speakers have two sets of RCA connectors-- one labeled PC, and the other labeled AUX. Reading the manuals, the two jacks appear to have different sensitivities. So if you use one set of connectors for your mac, and one for your PC, the more sensitive connection will be louder.

e.g,

the r980t speaker specifies 700±50mv for the PC, and 550 ± 50 mv for the AUX input.

But without more details on your setup (including the model number of your speakers, and whether you have them connected to both computers simulataneously), this is sheer speculation. It's also possible that your PC motherboard outputs a louder signal (for use with less sensitive headphones, for instance).

 

[oscarodas]

Try installing Boom 3D.