I have a problem and any suggestions will be greatly appreciated. I have a NAD T753 and Totem Arro for front and Totem Dreamcatcher for the surround and the sub. Great combo for music in Stereo and surround. When I go pass -20 db on my NAD the Arros start to clip but not the surround speakers, and I have the soft clip option on. Does this mean that I need more power for the front speakers (Arro)? Would it help if I buy a NAD C272 just to power up the Arros and use the T753 amp to power up the surrounds only? Is there a better way? I don't want to lose any sound quality.
I'm not an NAD owner, so by no means take this as anything but... rambling. Have you configured your front speakers with an +XXdB offset? I'm wondering if it's that even though you're at -20dB, the system has increased the output to those particular speakers to +XXdB (i.e. +20dB) and you're effective volume level on the fronts is 0dB. (I only wrote that because it seems your surrounds are soft-clipping when the front mains are.)
Anyhow, those Arros are like 86dB efficient, right? They're aren't "that" efficient as they're on the low end of the range I like (86dB - 92dB). This means they are power hungry. They probably sound real nice though when they have the right amp driving them!
You may have to look for separates to power them Arros. I don't know what others think, but the C272 may do what you need? I'm worried that the C272 is only about twice more powerful -- in WPC -- than your NAD T753, BUT, it will have more dynamic headroom than the T753... so could -- pardon the pun -- "soften" the amplifier's playback of the dynamic portions of your music and not (soft) clip (as often). This is a perfect case to have an "in-home" trial/demo!
Thanks geekboy for the avdice. The Arros are 4ohms and set at 12db and their sensitivity is 87db. My surrounds (Totem Dreamcatcher 4ohms surround and 8ohms centre) don't clip at all am their sensitivity is 87.5db. My listening romm size are 12x10.
Mohsen, well your front (main) speakers have more drivers in them and are larger, requiring more power. Plus you say you have them at +12dB, which is why you're clipping at -20db because you would be at -8dB (near max power) on the NAD.
Like I wrote, I would suggest demoing the C272 in home and see if it helps. You're probably only getting the soft clipping during dramatic/intense parts of music or movie passages, right? Not for "normal" listening levels. The T753 just may not be able to deliver the dynamic loads that ANY 4Ohm speaker would require... especially one that's 87dB (in)efficient. In general, 4Ohm loads are hard for most commerical receivers. NAD "receivers" has been known to deal with 4Ohm loads okay, but you have to realize that probably, when it's clipping, the speakers are presenting a 2Ohm (or lower) load to the receiver, demanding TOO much power and causing the receiver to go into protection.
Sounds like a power amplifier, like the C272, would have more dynamic headroom to handle the massive power requirements for what you want to listen to music/movies at.
Remember, if you go the C272 route, find a dealer which will let you "demo" one in your home. You don't want to be stuck with it if it doesn't work for you.
Thanks geekboy. I think that I need more power and a separate amp for the 2 front speakers would be the answer. I am looking for a used one; hope fully I can find one. I also contacted Totem and they suggested the same solution.
geekboy - get your facts straight. The Arros have the same number of drive units (2 in each) as the rear Dreamcatchers. The centre has more drivers (3). That said, none of this really matters. The Arros are a bit more difficult to drive than the other speakers, but not hugely so.
Mohsen, I find it interesting that +12db offset is required to set the Arros right. That seems oddly high to me in that system. I would check your surround settings since that just seems out of kilter with my experience. Are you single- or bi-wiring? If bi-wiring, have you removed the links between the main and treble connections on the back of the speakers? If this pans out, you may wish to take them back to your dealer to check them out and make sure there isn't something wrong with them - he'll be able to check them against his own demo pair.
If it all comes to nought and you really need more power (surprising in a room that small), the C272 will definitely give the Arros something to think about.
Frank and Mohsen: sorry on the drivers (and size). I misread something then. Must have been the center channel.
In any event, Totem agrees that it is likely that he needs a more powerful amplifier to power those front drivers. The +12dB offset is contributing to the clipping.
I have a T753 driving Dynaudio 42s, which is a speaker very similar to your Arros in its impedence curve rated 4 ohm with a rated sensitivity of 84db). I left my levels at the factory setting and even though I will drive the receiver hard, it has never clipped, despite the huge size of my room (20x 14x 18) which requires a lot of power to fill.
Look at it this way, when you up the levels to +12 or +8 for the Arros, you are eating up the headroom for those channels, so I am not surprised that the amp clips. I would dial them back to flat or +3 at the very most. Also check your rear levels, as well. The NAD remote allows you to easily change the relative levels of the surrounds and center speaker, and sometimes you can hit those buttons without realizing it.
I start the setup process with everything on 0db. Then in Test mode start with the left Arro, leave it on 0db and check the volume level (I use an SPL meter) and move on to the centre, ensuring it has the same output as the Arro on the left, move on to the right Arro and ensure this has the same output as the centre, then move onto the rears and eventually the sub (checked by SPL meter but adjusted later by ear since SPL meters don't work very well at sub-bass frequencies).
Now if you don't have an SPL meter you'll have to use your ears. Sit in the ideal position when making the adjustments. Don't automatically assume that the left and right speakers should be the same either. Some rooms are more reflective on one side than the other.