What source of music are people going to be listening to most of the time that would justify custom-fit IEMs?
It's not so much the quality of the source that you're listening to, although for the record I prefer flac or uncompressed wav myself. It's more about sound isolation, and/or if a set of standard fit IEMs will do the trick for you. Some people's ears don't work well with standard ones.
Also, the number of drivers matters. Single driver are just not going to give the frequency response to get the most out of the music.
Can you give me an approximate idea what these custom IEMs would cost?
I'd have to give it some serious thought before investing in custom fit phones. Will it be something worth investing just for my occasional airplane travel?
And no, I'm not planning on using these outdoors while jogging, or even hiking. Call me paranoid but, I don't like handicapping my sense of hearing while, I'm out and about in a public place. I like to be aware of the surroundings.
I'll check out the Westone and Ultimate Ears.
Ok, I probably did go a bit overboard with the custom fit...but Westone and Ultimate Ears make standard fits that are reasonably priced. You can get a pair of standard fit dual driver Westone for under $300 I believe. You may even be able to get triples for that much now.
One side benefit of standard IEMs over customs is in the little bit of ambient noise they let in. They're very isolating, yes, but not 100%, because generic sized foam can never completely fill the canal. It just can't. So you'll still hear that train coming. In terms of what I use mine for (live musical performance), I find my standards work better in some environments and customs work better in others. In a simple PA situation where I can't get every single instrument piped into my ears, having a bit of bleed-in ambient noise from the rest of the band actually helps. In a situation where there's very good stage monitoring and everyone's mic'd up and I can get a discreet mix of everything, customs are the way to go. But even then, an ambient mic or two is needed to help reduce that alienating feeling of being closed off from everyone.
If IEM's are on the table, I wouldn't even say that you need custom IEMs. Check out Etymotic. Extremely good sound quality, extremely good isolation, all with standard earpieces. Their HF5s are only $130, and are an absolute bargain for the quality of sound they offer. (And if you're so inclined, you can go the custom mold route with them, too)
Etymotic are exactly that: good value for the price you're paying for them. Re-reading what the OP is going for, especially the part about getting them even cheaper if possible, you may be right.
I'm a bit biased..when I buy something I decide my budget and then max out the quality I can get for under that price. So if I had $300 to spend on audiophile level headphones, HF5s wouldn't be on the list, simply because they aren't the best quality for the money I'd be looking to spend.
I agree tho that custom fits are not absolutely necessary. I should have made a better distinction there.
I figured, since I'm looking to spend about $300 I can give myself a few options.
1. Blow it all on one pair of over the ear headphones
2. get a decent pair of over the ear Senns for like $150-$200 and spend the rest of the money on In Ear phones
Well if you spend $200 on over the ears you're not going to get decent in-ear phones, and stay under $300 total.
When I started spending decent $ on earphones, I started with Westone UM2's. They were about $299 back then and now go for around $225 and they come with enough tips to ensure that you'll probably not need to go custom. I still have these 8 years later and they have been through hell and back with me. They also have better bass response than any IEM at this or lower price point. For someone who wanted to spend a bit and wanted great sound, they probably still represent a very good choice. I have no idea if there are better out there for that price but when I researched the Shure and Sennheisers were that price or more and they were only single drivers....and the key was, I had already used both of those brands offerings at the same price, and they sounded horrible. Just crap to my ears.
Which brings us to the final deciding factor: go listen to as many pairs as you can. Let your ears tell you, everyone hears things differently. Use the same device and the same song so all things are equal.