I’ve been to J&M twice(technically three times), the first time(two times) to remove a blown speaker from my car to send back to the manufacturer and reinstall the replacement, and most recently to install a sub amp. Their workmanship is outstanding, their labor price is very reasonable, they seem competent in discussing car audio systems, and they did exactly what I asked them to do, no more no less. I plan to come back for any future work I need done on my car audio system. Please note that I have no experience buying parts or equipment from J&M. This review pertains only to service.