You mean Onkyo receivers are not good for music ??
But most of the reviews have thrown 5stars for TXSR606!!!
Dilse, let me explain this to your without ruffling any feathers, and getting bashed up !!
The general perception in the market and in this forum is that Denon and Marantz are good for Music and Movies, and Onkyo and Yamaha are good for Movies and Music.
In terms of technology all these AVRs use similar or processors that are very close to each other. They all use 192/24 bit DSPs, high quality components, etc. The DSPs are from Burr Brown, Analog Devices, TI and similar companies. Though one brand may be popular for some time, they are neck to neck in terms of specifications and capabilities. For example, some time ago Burr Brown had reached legendary status and were even mentioned in movies. At that time, it was considered that any amp that used a Burr Brown had to be good.
Coming back to AVRs, it may be only Yamaha that, for the same price class, provides extra features in audio processing. For example, if a Denon or Onkyo has 15 sound decoding processing at a particular price point, Yamaha would have 17 or 20 decoding processing for the same price point. This is because Yamaha has designed and created it's own proprietary DSP chips that it uses in it's AVRs.
Even in video processing, all these AVRs provide the same capabilities at each price point. Sometimes I think the designers of these companies have a monthly meeting when they talk to each other to decide what to give for a particular model in each brand.
So what separates one brand from the other? It is possibly the sound signature.
Designers of these companies use their own methods to handle the sound signature. Unfortunately it is not pure science, so a bit of subjectivity creeps in. Marantz and Denon are supposed to be 'good' for music. Why? because they are 'warm'. What is warm? Well when you play music, maybe because of the recording or the way the song has been played, you may find some high frequencies jarring to the ears, or you may find some of the drum beats to be hitting your chest. A warm amplifier is supposed to recognise those notes and tone it down for you. Now in one amp, you cannot have two sound signatures, can you? So what happens is that the same sound signature is carried forward to movie sound, and there the toned down sound may not fit. For example if you tone down the sound of a bomb exploding, it will not sound good. Or if you tone down the high frequency of a whistle, it will sound unnatural.
Yamaha and Onkyo, on the other hand, are supposed to do just the opposite. With an emphasis on movies, they actually enhance the sound. So a drum beat will sound deeper, and a whistle may really hurt your ears as it does the actor. Yamaha and Onkyo may call this 'Transparent', while others call it 'harsh'.
The net result of this is that, in spite of using very similar technologies, these brands all sound different. It is very difficult for someone else to tell you whether one is 'bad' or 'good'. It will better to say that a particular brand's sound is 'good' or 'bad' to my ears.
Posting in this forum can help you shortlist a few models from a large set. This will be based on budget, specification, and matching the capabilities of the amp to your requirements. Once this is done, the ultimate decision making authority will be your own ear. You have to listen to each of the short listed models, and decide which one you like.
Happy hunting.
Cheers