100W, 200W, or 300W?

Digging through the Mac specs it appears that their own direct coupled design has 5 times the damping factor of the autoformer design. While it seems debatable if damping factor beyond 250 has real-world gain, these values seem to be within the “it might matter” range since they’re within the 0-250 range.

@eisenb11 It might interest you to know that no speaker made needs more than 20:1 damping factor and many sound better with less! So more damping factor, if that is the only metric, totally does not matter. Damping factor looks better on paper than it sounds in real life- again, given that such is the only metric. Distortion is far more important, both the distortion that an amp makes and also that which it does not. In general with most amps these days higher distortion is often a sign of lower ordered harmonics to which the ear is relatively insensitive. OTHO very low distortion might only be higher ordered harmonics and the ear is keenly sensitive to those and interprets them as brightness and harshness.

@eisenb11  If you can't clip your existing amp then possibly yes to a class A amplifier. High end is all about nuance!

'Echoey' isn't good- that makes the room more lively and harder to enjoy at higher volumes. So you may find that once the treatment is in place that you need more power. My advice is to sit tight until the room treatment comes in and you've had some time to fiddle with it to see what works. You may find at that point that more power will be useful, as that room treatment will absorb some acoustic power and has the ability to tame harshness in the room; both will cause you to turn the volume up higher.

A mark of a good system is when you can't tell that its playing loud; that it sounds relaxed and effortless, yet if you try to talk to someone right next to you, you find that you have to yell.

My room is a little smaller than yours: about 15x15x10 high. Sub is eventually on the TODO list to fill in the bottom end - but after amp and streamer upgrades.

@eisenb11 If your room really is these dimensions then I don’t think you’re going to need all that much power since your room isn’t that big. If you are not overloading your old harmon kardon then this is all the proof of that you need. But you do have a different problem- your room is square!

It is very difficult to get the bass to work properly in a square room! The most elegant solution is to employ a Distributed Bass Array and to correct minor problems, add room treatment. Standing waves are a huge problem in a square room, and room treatment won’t fix it on its own. You’ll need to break up the standing waves (otherwise you’ll have one-note bass with the rest of the bass almost non-existant).


If this were my system I would be looking at this issue first, rather than looking at increasing amplifier power! You need that amplifier power to make bass notes without distortion, but if they are being canceled out by standing waves in your room, no amount of power will fix that- because the more energy you put into the bass is irrelevant if it simply cancels itself.

The best distributed bass array system I’ve seen is known as the Swarm and is made by Audiokinesis in Texas. Essentially it is 4 subs, each about a 1 foot square by 2 feet high. You place them directly against the walls. Two are in front, and the other two are asymmetrically placed elsewhere in the room, maybe one to one side and one in the rear; by doing this standing waves are broken up and you get even bass distribution in the room down to 20Hz. They do not operate above 80Hz so you can feed them a mono bass signal (so they can all be fed from the same bass amp) and as long as they do not go above 80Hz then the main speakers will convince you that bass drums and bass guitar is in front of you since their harmonics will be coming from the main speakers.

I am very unconvinced that you need more power. In particular, if you took the bass notes out of the main speakers (some subwoofer crossovers do that) then you’ll find your amp has plenty of power.