I believe you may have encountered this term before or could be using this setting right now. To the best of my knowledge, this is a sound setting that only an AVR will have. You must be wondering what so special about this sound mode and what does it do, isn’t an AVR just about processing video and surround sound formats.
Is pure direct sound suppose to enhance the sound quality or is it some sort of an EQ setting? No to the latter, and yes & no for the first. I will be blunt, this sound mode could be either a useful or completely useless feature for an AVR.
What is Pure Direct Sound
Most AV receiver brands such as Yamaha, Pioneer, Onkyo, etc. has this type of sound mode, it may be named differently but the functionality is still similar. When you set your AVR to this mode, you are simply allowing sound to be fed directly to the amplifier bypassing any EQ, crossover, calibration settings, and other digital processing, to achieve the best possible high-fidelity sound. This also helps to avoid coloring of the sound signal. How ‘pure’ the sound is really depended on the brand and the AVR model. There may still be some digital treatment been applied to the signal though.
Some models may even expand their frequency range from the standard 20 Hz – 20 kHz to 10 Hz – 100 kHz when you engage pure direct sound. Some even turn off all video circuitry including the display, to completely convert the AVR into a pure stereo amplifier.
Why would I need Pure Direct Sound
We all know that AVR is mainly used for the home cinema experience as what it does best is to process the video to Full HD/4K and sound to surround sound formats such as 5.1, 7.1, Atmos, etc. As you can see the AVR is extremely busy with all its’ circuitries running in unison and the sound is heavily treated with digital processing and calibration settings. This is why AV receivers are never used or will never be the first choice when it comes to music except for live concert performance via Blu-ray. Audiophiles will usually bypass the AVR entirely to their stereo preamps and purely use the receiver as just power amps to drive their main speakers during music playback.
What if you can’t afford a stereo preamp? If your AVR belongs to the high-end model range and comes with an inbuilt DAC, you can still use the Stereo mode. But what if your AVR is just an entry-level model? Do not dismay, this is where Pure Direct Sound comes into play. With this setting, you can still listen and enjoy high-quality music playback. When is time to watch a movie, you can simply switch it back to your surround sound setting.
You are getting the best of both worlds just by using an AVR. Why would anyone buy anything else other than an AVR, you might ask? Oh, there are drawbacks to this, and here’s why.
Disadvantages of Pure Direct Sound
If you are using satellite speakers and a subwoofer combination then pure direct sound won’t work well for you. Usually, this mode will bypass the subwoofer too. Without a subwoofer, your satellite speakers will lack so much in the low-frequency range that will make it sound bad. You will require full-range speakers for this case if you do not, then you can forget about using pure direct sound. Some AV receivers still have another mode to overcome this, Direct Sound, which still uses the subwoofer. But this is a compromise, like an in-between, be it a slight improvement over the standard stereo mode.
Even if you are using a pair of full-range speakers such as floor-standers as your mains, there is still another drawback which is your AVR does not have enough power to fully drive it, causing the amp to clip and damaging your speakers. As you are currently missing the bass support from your active subwoofer, and making the AVR work even harder than before.
Another disadvantage is that you will always lose to a proper stereo setup where the imaging, speed, precision, and clarity will always be one level above an AVR in terms of music playback. Likewise, a stereo setup is never meant for movie playback.
If all or most of your music sources are in 5.1 sound format then the pure direct mode will make use of your 5.1 speaker system. It will only use your L/R main speakers for 2.0 sources. So this is good news for some of you out there who will really benefit from this setting. Then again, you may still prefer the calibrated sound setting by Audyssey. You could do an A/B sound test to see which best suits your taste.
If you are like most of us, who couldn’t afford 2 separate home audio systems for music and movie playback. Then you need to decide which is more important to you, whether is music, movies or both. If you choose either movies or both, then you should just get an AV receiver, and just be happy with the standard stereo mode for music playback. I have a friend who listens to music using multi-channel stereo mode and he truly enjoys it, not a single complaint. Furthermore, he is using an HTIB system (home-theatre-in-a-box) made by Sony.
Be it pure direct sound, direct sound, or any other modes, the most important thing that matters is that you enjoy your music. We should all be more like my friend, to avoid disappointments and be easily contented with whatever sound quality, then again his HTIB cost about $1,500.