Pass Lab XA30.5 with Totems

There are many recent inquiries about the suitability of the Pass Labs XA-30.5 and XA-60.5 amplifiers for use on speakers that most agree require more power than these amps provide.

It seems like "hope against hope" that somehow the actual power delivered by these amps is going to exceed the manufacturer's power rating, thus allowing people to afford a lower powered Pass Labs amp than they actually require.

Owners of these speakers may find that if they listen at low to moderate levels in small rooms that these amps will provide sufficient power, however in many cases the amps won't be sufficient for realistic (translate to "live") listening levels in medium to large rooms.

Keep in mind that a VERY important factor in how much power you need is the dynamic range of the music you listen to (meaning the DIFFERENCE in volume between the loudest notes and the softest notes).

One of the most demanding kinds of music in that respect is classical symphony orchestra, if it is well recorded with minimal compression. If you set the volume control to produce modest volume levels at your listening position of say 70db on soft-to-medium passages, brief dynamic peaks on orchestral crescendos, bass drum beats, etc., can easily exceed 100db. 100db requires 1000 times as much power from the amplifier as 70db.

On the other hand, if you listen to typical highly compressed rock music, which may have a dynamic range of only a few db, and you listen at modest volume levels, you will need far less power. For instance, an 85db peak only requires 1/32th as much power as a 100db peak.

Regards,
-- Al

Thanks to all for the valuable information. It all makes sense and points me in the right direction to follow as i just got the amp.

If you love the amp, and it doesn't quite work with the speakers (you may be fine), it is certainly an amp worth building a system around, it is a great SS amp. It was extraordinairy with my Merlin VSM-MXes, but still preferred an OTL with the speaker. I agree with TVAD observations about the desire to have these XA.5s provide enough power, I would say that they perform as they do have more power than their ratings would suggest, but there is a reason for the higher powered versions.

Every system should be built around speakers, not an amplifier or source(s).

Starting with an amp is like buying a set of tires then finding a car to fit them.