This is a vintage pair of Acoustic Research Connoisseur 40t speakers. The brand is known for producing high-quality audio equipment, and these speakers are a prime example. They have a classic design and are sure to enhance any audio setup. Here’s your chance to own an excellent example of Acoustic Research 40t Speakers. They were stapled shut when I bought them. Knowing the age of the speakers, I had to open the box and check the condition of the surrounds. The woofer surrounds had failed and needed replacement. I carefully removed the woofers and sent them to Simply Speakers. After the repair, I reinstalled the woofers and began the break in process. Here’s the process I followed. 1 – First 100 hours – low volume music only. The music should be general/vocals with modest bass. Please don’t use any artificial and/or single tone signal signals this risks creating a memory patten in the outer 7 to 10 micron cone substrate. You can run the drivers in free air or near free air, but pay attention to the physical movement, the driver’s power-train should not move more than 1mm. 2 – From 100 hours to 300 hours, gradually increase the load to normal listening levels. Typically and depending on room size, the volumes should be around low 80’s dB near constant loads with peak loads not exceeding 86dB. For those without any SPL measuring equipment, set your system to moderate listening levels. You should be able to hold a conversation without raising your voice while the drivers are being run. 3 – From 300 hours out, the driver’s power-train will enter its optimal load phase on its suspensions. Markaudio driver suspensions are critical components as they have to cope with long-throw demands of the cone/coil. I recommend some care from 300 to 500 hours as fully optimised suspensions will give you many years of reliable service life. Bass loads are available but go a little easy on the volume until passed 500 hours. These are the best examples of these speakers you will ever find, period. There’s two tiny imperfections at the top of the front of one of the speakers. I have no idea how they got there. Could have been in the manufacturing process.