Does anyone remember the phone call listening room inmprovement scam?

It was the ultimate snake oil tweak ever sold here on Agon and wish I'd saved the description. You pay like $60 and the seller would call you on the phone which you would hold in your listening room. He'd then play a signal (maybe like a dial up or fax machine connection noise) through the phone. Afterward your listening room would instantly sound better as this was to make a huge improvement. That's all I remember wondering if anyone else can recall any details? We are traveling back in time about 15 +/- years on this scam.