Yes, the McIntosh has 4 ohm speaker post taps for use with lower impedance speakers. In a 20×18' space, if you go with 4 ohm speakers, you should look for a sensitivity spec of at least 89 db and benign phase angles at low impedance (for this you'll need to find some published measurements, such as those in Stereophile). If you want to play it safe, speakers with a 90+ sensitivity spec and an 8 ohm nominal impedance should be easy on your Mac. Others will tell you that you need super efficient speakers with 97+ sensitivity ratings, such as Zu Audio or Klipsch. Not True, unless you intend on destroying your hearing.
Other than those concerns, you simply need to audition some various models. Ask dealers if you can bring your amp for the audition. Ask them to position the speakers to your liking.
Everyone here is a fanboy of one or more brands and they'll claim their favorites are the best. That won't do you much good, as everyone hears differently.
I prefer the British monitor brands, but I understand why they're not exciting enough for many folks. I dislike the sound of Focal and Golden Ear speakers, but many love them and think they're a great bargain.This is why it's a personal matter and auditions are critical.
If you have no dealers nearby, consider the internet direct brands like Zu, Tekton, Ascend Acoustics, and Salk Sound. I believe all these brands will let you keep the speakers for a trial period and return them for the cost of shipping. Also, some internet dealers like Music Direct and Crutchfield will allow a trial period.
Other than those concerns, you simply need to audition some various models. Ask dealers if you can bring your amp for the audition. Ask them to position the speakers to your liking.
Everyone here is a fanboy of one or more brands and they'll claim their favorites are the best. That won't do you much good, as everyone hears differently.
I prefer the British monitor brands, but I understand why they're not exciting enough for many folks. I dislike the sound of Focal and Golden Ear speakers, but many love them and think they're a great bargain.This is why it's a personal matter and auditions are critical.
If you have no dealers nearby, consider the internet direct brands like Zu, Tekton, Ascend Acoustics, and Salk Sound. I believe all these brands will let you keep the speakers for a trial period and return them for the cost of shipping. Also, some internet dealers like Music Direct and Crutchfield will allow a trial period.