CM9 and Rotel ? class D or A/B

[M&B]

My husband and I have fallen in love with the CM9s and the Rotel system. We were all set with the 1575 and 1570 rotel amp but have recently been advised to go back to the 1550/1582 stereo system by the only sales guy we can find that seems to be able to offer both. Part of the problem is that we haven't been able to listen to both yet to get our own comparison and we'll try to sort that out, but we'd be interested to hear opinions from anyone else who has.

[stuofsci02]

Excellent choice on the CM9.. I have always liked that speaker.

As far as electronics I am assuming you are referring to the RSP-1570 and RMB-1575 vs. RSX-1550 and RB-1582.

If this is the case there are some significant differences in the setup that make this not really just a Class A/B vs D case.

The RSP-1570 is a dedicated Pre/Pro 7.1 with all the new decoding formats, but because it is a pre-pro it has no amplication. The RMB-1575 is a 5 channel power amp. This type of separate setup tends to be considered higher end because the amplifiers are not in with the Pre/Pro as they would be in a AVR. This means that down the road when a new decoding format comes out you could change the RSP-1570 to something new and continue to use the RMB-1575 power amps. Note that because you are selecting a 5 channel power amp you will not be running 7.1 but rather 5.1 assuming you have center channel and surrounds. The beauty of this setup is that later if you like to add a nice two channel power amp for your CM9s, you can and then you can have 7.1 if needed.

The RSX-1550 is a 7.1 AVR meaning the Pre/Pro and amps are in one chassis. In general pre/pro with amp is preferred to AVR if all else is equal. One thing to note is that it only has a 5 channel amplifier meaning if you use it alone you will have 5.1 just like in the other option. However it has been suggested that you add a better two channel amplifier RB-1582 for your CM9 mains to give you full 7.1. This means you are ahead with an extra two channels in this setup and the dedicated stereo amp should help your CM9 shine. The drawback of course is that down the road when a new decoder format comes out you would have to replace the whole AVR including the 5 amplifiers if you wanted to be able to decode it.

Aside from those major differences in setup, I would have to suggest to listen and see what you like best. Also decide if 7.1 or 5.1 is important to you.. What speakers are you running for your center and rears?

Also the Class D runs much cooler and uses less energy. It can be put almost anywhere. The Class A/B tends to be much warmer (hotter) and should be placed somewhere with some airflow.