You might want to do a search for threads on speakers that work well with your Pass amp. The right amp > speaker pairing is the key to getting the best out of both. I'd guess the topic has come up before. You could even give Pass Labs a call. They would probably be willing to give you some advice.
You don't need ultra high efficiency speakers that are designed for low power tube amps. A speaker in the 89 db and up sensitivity range with a nominal impedance of 4 ohms should work fine.
Sensitivity tells you how loud your speaker will play for a given input of watts. Higher is louder.
Impedance tells you how hard your speakers are to drive. Lower impedance is harder to drive. Harder to drive means a more powerful amp. Your Pass is a medium power amp.
Manufacturers give this spec as one number but impedance varies with frequency. A 4 ohm nominal impedance may dip to 2 or even 1 ohm at certain frequencies. You can get this type of info from reviews where measurements are done (Stereophile online is a good source) or by contacting a dealer or manufacturer. Reno HiFi is a Pass Labs specialist. They might be a good source of advice.
You don't need ultra high efficiency speakers that are designed for low power tube amps. A speaker in the 89 db and up sensitivity range with a nominal impedance of 4 ohms should work fine.
Sensitivity tells you how loud your speaker will play for a given input of watts. Higher is louder.
Impedance tells you how hard your speakers are to drive. Lower impedance is harder to drive. Harder to drive means a more powerful amp. Your Pass is a medium power amp.
Manufacturers give this spec as one number but impedance varies with frequency. A 4 ohm nominal impedance may dip to 2 or even 1 ohm at certain frequencies. You can get this type of info from reviews where measurements are done (Stereophile online is a good source) or by contacting a dealer or manufacturer. Reno HiFi is a Pass Labs specialist. They might be a good source of advice.