there is a difference between the salesman and the installer. salesmen don't need to know how it works, just how to sell. the good ones know both installation and sales. installers need to know how it works. i talk to both, if the installer won't talk to you, don't let them touch your car. at a minimum, they should be willing to discuss mounting and wiring options. the shop should have a photo book of installs, to showcase their work and talent. if the pictures are all old, you know that the good installers have left.
shops get a lot of people who think they know what they are talking about because of stuff they read on the internet and stuff their friends say. the staff know more about the product they sell than you do, so keep that in mind.
most issues are situations where there is a lack of mutual respect. people get combative and defensive easily, and it can be difficult to have a civil conversation once someone has felt challenged.
no one is perfect. some shops will bash gear they don't sell, then a year later they sell that and say it's awesome. i've caught shops in that situation before. i've lived here in the QC most of my life. i've been going to the local shops for almost 20 years. we had four decent independents and a few big box stores (American, Ultimate, BB). now we're down to two independents and two box stores. one of the independents, Solar Vision in Davenport, IA is excellent. great staff, good installers, and they have been there the whole time doing a good job. the owner and staff used to be active in IASCA and always hosted events. the other shop has a bad rep because they higher HS students in order to get their friends on board. they sell decent stuff, but their staff are difficult to talk to. I've auditioned Focal K2P there and somehow they made them sound distorted and just terrible. Both stay in business due to remote starts, tinting, and other vehicle accessories. Most people around me just want lots of bass, no music, and no money. For a shop, it's hard to justify spending a lot of time on SQ installs when no one is willing to pay for the gear or install.
car audio knowledge comes from experience. sure, you can read what other people say on a forum, but until you try it and understand what is actually happening, you're only repeating what you've heard... which isn't knowledge.
most of the industry has supported the idea that capacitors solve voltage drop and are required with large systems. everyone on this forum believed that at one point and time. so none of us can mock others for thinking the same. if you can't present evidence and electrical calculations/explanations to support your claims, don't expect someone to believe you because you read it on the internet. the best evidence against capacitors is a calculation of energy storage and release (Joules). the internet is a place for misinformation as much as it is for information. i see a lot of incorrect statements made on forums, so you can't believe everything people say. if you want to know something, pick up a textbook on the subject and start studying. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif