Which regulator for both very cold & warm waters?

[IncreaseMyT]

Also when you add in the fact you can environmentally seal your piston reg, I am failing to see the advantage of a diaphragm?

 

[eelnoraa]

But there is a performance difference between the 2 types of regs and its worth noting, I think.

What? B2 out perform Flathead?? I am not saying that can't be true, but that isn't 1st stage design mechanism related.

 

[eelnoraa]

Also when you add in the fact you can environmentally seal your piston reg, I am failing to see the advantage of a diaphragm?

Not every balanced piston can be seal. Atomic being one that can. Most others can't. Keep in mind, each sealing of atomic cost $40 or so crystolube. And everytime you open the 1st stage, for any reason, you will need another $40 for repack. It is one of the big disadvantage of sealing an atomic piston. I have enough myself to feel the pain

 

[IncreaseMyT]

What? B2 out perform Flathead?? I am not saying that can't be true, but that isn't 1st stage design mechanism related.

The performance difference between a diaphragm and piston reg. A piston reg can deliver a lot more air. Maybe even twice as much.

We can sit here and argue whether or not a diaphragm reg can be over breathed, but there is no doubt a piston reg can out pump a diaphragm.

 

[runsongas]

max airflow is determined by the 2nd stage in almost all cases, so the fact a mk25 can flow a lot more air doesn't mean much. last i checked, you can only stick one second stage in your mouth at once. if you really are worried about getting enough air, you want a jetstream/xstream from poseidon.

 

[eelnoraa]

. A piston reg can deliver a lot more air. Maybe even twice as much.
.

No disagreement here, In fact, we are talking about different things. One is a measurable theoretical limit but not in a realistic usage. The other is a practical, maybe within 5 sigma usage.

The truth is modern regulators are good performers. When properly tuned, I have serious doubt anyone can tell the difference in breathing efforts between balanced piston and balanced diaphragm 1st stage. Piston inherently has higher flow rate. But sealed diaphragm inherently does better in cold water. Unbalanced flow by piston also inherently does better in cold water than balanced flow through piston. Each design has its compromises and will be better for certain usages.

 

[Diving Dubai]

At OP

I run the AL legend lux supremes on my main gear, Apex XTX50’s on my teaching rig and Sidemount rig and AL legend lux for my deco regs

Both are great, I like the variable breathing adjustment on att. The Apex also have the dive/pre-dive lever

No discernible difference underwater even down to 50m

I have my regs tuned to the edge by personal preference

I prefer the AL first stage because of the ACD which makes it worry free

My XTX 50 all have 5th port ant turret which is also useful, but only essential for SM

I can recommend both and I treat my regs hard

 

[Storker]

For my first 40 dives or so I used a diaphragm reg and never had any issues. But there is a performance difference between the 2 types of regs

You "never had any issues" with your diaphragm reg set, but still think it didn't perform sufficiently?

Hmmm, OK.

 

[Centrals]

I never had any trouble breathing when I was down there, I am just saying my point of view is little more drastic than some others. And that I exerted as much energy as I would in a 20 minute workout lifting weights. For my first 40 dives or so I used a diaphragm reg and never had any issues. But there is a performance difference between the 2 types of regs and its worth noting, I think.

The late John Bennett used Apeks TX100(FST diaphragm 1st stage) on his 308m dive. Is it good enough for you?

 

[lexvil]

At OP

I run the AL legend lux supremes on my main gear, Apex XTX50’s on my teaching rig and Sidemount rig and AL legend lux for my deco regs

Both are great, I like the variable breathing adjustment on att. The Apex also have the dive/pre-dive lever

No discernible difference underwater even down to 50m

I have my regs tuned to the edge by personal preference

I prefer the AL first stage because of the ACD which makes it worry free

My XTX 50 all have 5th port ant turret which is also useful, but only essential for SM

I can recommend both and I treat my regs hard

The very existence of an ACD would cause my worry.