Sony Muteki STR-KM7 AV - Review

Sony Muteki STR-KM7  is a 7.2 channel AV Receiver for the HT-M7 home theater system. It processes full HD input signals and delivers 2012W RMS music power to a 9-speaker box configuration. I have owned this Muteki STR-KM7

for two years now and I can comfortably say I'm very satisfied. It is a home theater built for action. It is incredibly loud; its two Subwoofers are designed to deliver a heavy punch for majority of media sources. 

If you are a movie lover and a fan of loud parties, a phenomenal 2012W RMS of music power is available to the speakers. You will enjoy every bit of action with incredible clarity and volume. For movies enriched with bass effects (LFE channels), the subwoofers give you a thunderous rumbling effect with clean bass and remarkable voice clarity. This home theater is able to reproduce low frequency notes with great clarity and power. The metallic cone speakers adopted by Sony make it possible to reproduce sound with minimal distortion. 

The STR-KM7 processes Dolby TrueHD, HD Digital Cinema Sound and DTS 96kHz/24bit audio formats. In addition, it allows 3D and HD picture pass-through. DTS Master Audio is down mixed to DTS 96kHz/24bit. Some models however, do not process Dolby TrueHD and DTS Master Audio. Always confirm this for your model before purchase. Logos of Dolby TrueHD, HD Digital Cinema Sound and DTS 96kHz/24bit must appear on the AV receiver unit and packing boxes.


I like how this STR-KM7 reproduces the sound of the canon while watching the hunger games DVD; it gives you a heart wrecking boom! It is without doubt that any movie with this home theater is always a pleasure to watch. The STR-KM7 is built for movies, and gives a true cinematic experience as advertised! From my continued use I have noticed movies encoded in DTS 5.1 or Dolby 5.1 audio formats or higher give the best experience.

The Sony Muteki STR-KM7 is easy to automate and easy to set up if you know what you are doing. It comes along with an elaborate manual detailing every bit. For me, I normally connect a PC/Laptop, HDMI Blu-ray Player and HDTV/SATV; and control everything via an Android phone.  

The STR-KM7 is delivered in two boxes weighing 65+34 kgs. It comes along with 9-aluminium cone speaker box system; 1 center, 2 surround, 2 surround back, 2 subwoofers, 2 front speakers and a single remote. The STR-KM7 has been sold in several other models like for instance; Muteki STR-K7SW - a model for middle East and Africa. All these are just AV receiver variants used with the same HT-M7 home theater system, but with only slight improvements among them and tailored for specific markets.

Like any other AV receiver, the STR-KM7 has its downside as well. I don't get enough Bass especially when listening to music. I would have loved to get a little more punch from the Subwoofers but they seem to max out at half volume (though even at this level it is still good enough for the price) and any further increases in volume seems to affect only the front and surround speakers. This leaves you craving for more bass. At maximum volume the bass effect seems to get blanked out by the sound from the front and surround speakers. It is more evident when listening to mp3 music and media not loaded with LFE effects. It's like as though, some channels lose power as you turn up the volume. The KM7 will never set your floor into vibration because its deep bass drivers are not designed to respond to audio frequencies lower than 100Hz. Deep bass frequencies lie somewhere between 20Hz and 100Hz. So if you are the kind that enjoys deep bass that rattles your spine, this is not for you! Noteworthy though, the STR-KM7 is very loud, even at half volume it delivers just perfectly, loud enough to satisfy your ears!

If you choose to sync the Sony Muteki STR-KM7 with the TV through BRAVIA sync, you are able to control it through the TV using a single remote. It is able to recognize the TV output selected. I have tested this on a Phillips and a Sony TV. I cannot guarantee whether other TV's will behave the same way. Though, the down side of this sync, is that sometimes the sound output gets distorted  and may require a reset to normalize.

The USB playback option is very limited. This Sony Muteki STR-KM7 can only play WMA, AAC and MP3 files of bit rates not more than 192kbps and it is unable to read NTFS formatted USB devices, portable HDDs for that matter. It becomes slower between playbacks for devices stacked with a large volumes of audio files. It allows up 100 folders and maximum of 8-level folder depth thereby limiting you on the number of hours and precious audio file playback. A solution to this is to connect a portable playback device to one of the AV ports on the rear panel instead of using USB; giving you the luxury of playing all kinds of files without worrying about system limitations.

Surprisingly, the Sony Muteki STR-KM7 has fewer manual controls making its remote an indispensable part. You have to keep it far from destructive kids lest you get stuck with a box you can hardly operate and program. Overall, it is a fantastic system built with an extra touch of class. If I were to rate it on a scale of 1-5, I would give it a 4.8. For more information and detailed technical specifications of the STR-KM7, please visit tech specs of the KM7. 

A few Notes:

• It should be noted that this system is rated 2012W Total RMS power. The speaker output ratings given are obtained about a specific frequency (i.e. 1 kHz) and speaker load (say 6 ohms) as indicated instead of the entire signal range of 20-20kHz. For this reason the very high values are justified. In addition, the high aggregate harmonic distortion value means at some point you may experience some sound discomfort. I have experienced this during my continued use of the KM7 especially while playing some MP3 files from a laptop. Turning the volume down a bit,  distortions become less pronounced. 

• If files are played from a high quality source, the output is similarly of a high quality. Playing files from Android phones and tablets has always given me the best output quality at all volumes. For best sound output from all sources, it is advisable to connect all inputs to an audio distortion correction unit and pick inputs to the home theater from the outputs of this unit. 

• Currently, 7.2 channel digital media is not readily available. Most media copies available commercially are recorded in the traditional 5.1 channel format. This means a 5.1 channel media source will never give you the sound effects as intended by the recording sound engineer much as the KM7 tries to predict and reproduce the remaining channels for a 7.2 channel output configuration. 

• The STR-KM7 is not network AV receiver; does not support WiFi, Bluetooth Streaming and NFC pairing for Bluetooth. Automation is very limited to the HDMI-CEC or BRAVIA Sync features.  

• The HT-M7 i.e.[STR-KM7 + 9 speaker units] currently goes for $999.99 buying price, which is comparatively lower than other high end home theater systems in its category. Even if this is a 2012 make I would not think twice cashing in on it because it gives you more than its price tag can fetch! 

• In case you are interested in the user and service manuals, just drop me an e-mail.

• You might also find the STR-KM77 particularly interesting.