[MACinMTL]

Nevermind!

 

[Spyro]

Might want to post this in the "Headphone"  section

 

[MACinMTL]

Nevermind!

 

[GREQ]

The loudest headphone I've ever owned is the slightly vintage Pioneer SE-450.
Funnily enough, it's a closed back DJ headphone, but it's very sensitive and gets really loud really quickly.
I'm sure it would suit your needs quite well, and I think it'd be difficult to find something better.
You can get them really cheaply 2nd hand. Usually around $25.

 

[MACinMTL]

.

 

[Claritas]

Grados leak a lot and I don't see why you wouldn't be able to turn up the volume with them.

KSC75 with or without the headband mod.

 

[GREQ]

Grados leak a lot and I don't see why you wouldn't be able to turn up the volume with them.

KSC75 with our without the headband mod.

The problem with both of these is that you only predominantly hear the upper frequencies being leaked.
The SE-450 actually leak a decent amount of mids and high bass, AND they leak louder at the same source-output volume 

 
http://www.ebay.co.uk/itm/Vintage-Pioneer-SE-450-Stereo-Headphones-VGC-boxed-/321352936546?pt=UK_AudioVisualElectronics_HomeAudioHiFi_Headphones&hash=item4ad220ac62
But I guess you don't live in the UK. 

 
Whereabouts are you based?

 

[MACinMTL]

Nevermind!

 

[lin0003]

Grados leak and don't isolate at all. 

 

[Claritas]

Those issues with Grados can be fixed with modding: bass vents and tapped cushions. But you may be right about the Pioneers, GREQ.

 

[kilspeed111]

The beats studio are portable, are loud as f#ck, and leak more than my neighbours throwing a house party. They are quite expensive and have a terrible build quality though. Also the sound quality is pretty bad.
I'm talking about the original beats studio's, not the beats studio 2.0, these leak next to nothing.
 
I would never recommend beats to anyone, but well.. This might be one of the rare times.
 
Oh they are also closed by the way, so no worries that something might get stuck in the driver.
 
Edit: If you mean that you can still hear what's around you, then nevermind this post. I thought the sound leaking out.. You don't hear a thing with these on.
Edit2: After reading it again (I somehow managed to skip the "around the neck" part), you won't even need an expensive one (like the beats studio), I don't know any cheap loud headphones though, sorry. The post below this one seems like a good option though!

 

[dj1001]

why not go for a super long life rugged Bluetooth speaker, and couple it with a large external battery to charge not only the speaker but any other devices.
 
I'd recommend the Braven BRV-1, it is waterproof, drop proof and has a 12 hour playtime. I've left my braven in my car turned on for a week and it still had 70% battery left.The BRV-1 can be found for under $100 at most retailers
http://www.braven.com/braven-brv-1-waterproof-bluetooth-speaker.html
 
 
I'd pair it with a large10,000 mah battery such as this
http://www.amazon.com/EasyAcc%C2%AE-Brilliant-Ultra-Slim-Bluetooth-Smartphones/dp/B00H9BEC8E/ref=sr_1_2?s=wireless&ie=UTF8&qid=1395509770&sr=1-2&keywords=10000mah+external+battery
 
you could also try to find the braven 440 which has the same internals as the brv-1 in a cleaner but still waterproof case, the 440 usually sells for around the $50 mark.

 

[GREQ]

Those issues with Grados can be fixed with modding: bass vents and tapped cushions. But you may be right about the Pioneers, GREQ.

My Grado already has 4 vents per side opened up, and I honestly don't think it would come close to the Pioneer with the rest open.
They're already leagues apart on the leak scale - these Pioneers are truly something to behold. When blasting they sound better than some of these cheap little radios or mobile telephones.
 
I am liking the portable bluetooth idea though. Much more practical, but also MUCH more expensive.

 

[b0000]

i was thinking of the k1000 before i actually read the post lol.
 
For your needs, i'd say you should just go with earbuds like the yuin pk1 or pk2 or pk3. Koss ksc75 works too (maybe).

 

[Claritas]

i was thinking of the k1000 before i actually read the post lol.

That's a good idea! I want pictures of "rattlesnake walk with K1k."