Reg breathes hard when swimming upside. Solutions?

[DA Aquamaster]

When I took the SP Regulator Tech class, they mentioned that the EN250 standards of WOB are what killed the D400. Something about the exhalation portion requiring too much effort and that the X650 had better numbers during this phase. Any thoughts?

The D400 does have a smaller exhaust valve but I don't think the exhalation effort is excessive. The X650 does use a very large oval exhaust valve, but ease of exhaust is not the only factor. When you design a regulator you have to look at the big picture and not get hung up on one specific criteria.

In my opinion, EN250 standards as a whole have done a grave disservice to the scuba industry as the individual standards by themselves tend to reward engineering that ignores the system concept and instead focuses only on small isolated milestones of performance. The result is a reg that may meet the qunatitative performance standards but does not offer the same degree of qualitative performance.

What is worse, some standards, such as the EN freeflow standard, have required amny excellent performing regulators to be severely detuned to meet what is in the end a totally worthless standard. I think this freeflow standard and the requireing detuning t meet it had a more severe impact on D400 performance.

Do you feel that these WOB numbers are used alot like megapixels are for advertising digital cameras, where more isn't always better?

Absolutely. There are 10 megapixel cameras that are still compact cameras with crappy lenses and sensors that generate so much heat that anything approaching a slow shutter speed introduces excessive noise in the picture. On the other hand, my 6 megapixel Nikon digital SLR has not much more than half the megapixels but will deliever truly superior image quality. And even with "only" 6 megapixels, I can get 11x17 sized prints with no visible grain in the image. So the extra 4 megapixels is not needed and if it comes at the expense of image quality at higher ISO's or slower shutter speeds, it would actually be undesireable.

In the same way WOB numbers really do a poor job of reflecting the qualitative performance of the regulator and above a certain point, it is the qualitative measures that really count. In some cases, the "good" numbers are produced with a side effect of unnatural breathing performance that negatively impacts those very important qualitative measures.

The reality is that the average customer understands quantitative data in ads, and qualitative research is much harder to do well, so the marketing people focus on quantitative numbers and WOB fits the bill perfectly - even if it really gives little useful information.

The problem is that the marketing department drives the engineering department in many companies and standards like the EN 250 standards make it even worse. I tend to embrace diversity in all its forms, but I really don't care whether my regulator meets a European standard, especially when those standards are turning regs into mediocre performing clones of one another that qualitatively perform at a lower standard than their predecessors did 15-20 years ago. In my opinion, regulator development has flatlined over the last 10-15 years and I think the rush by the rest of the world to accept european norms to be able to sell in the european market are largely responsible.

 

[Cheekymonkey]

I think you hit the nail on the head here, they are going for small milestones, probably bonuses at work. Instead of trying to make an overall better product, the one or two talented engineers put alot of work into their side and the rest probably coast.

 

[xiSkiGuy]

The D400 does have a smaller exhaust valve but I don't think the exhalation effort is excessive. The X650 does use a very large oval exhaust valve, but ease of exhaust is not the only factor. When you design a regulator you have to look at the big picture and not get hung up on one specific criteria.

In my opinion, EN250 standards as a whole have done a grave disservice to the scuba industry as the individual standards by themselves tend to reward engineering that ignores the system concept and instead focuses only on small isolated milestones of performance. The result is a reg that may meet the qunatitative performance standards but does not offer the same degree of qualitative performance.

What is worse, some standards, such as the EN freeflow standard, have required amny excellent performing regulators to be severely detuned to meet what is in the end a totally worthless standard. I think this freeflow standard and the requireing detuning t meet it had a more severe impact on D400 performance.

Absolutely. There are 10 megapixel cameras that are still compact cameras with crappy lenses and sensors that generate so much heat that anything approaching a slow shutter speed introduces excessive noise in the picture. On the other hand, my 6 megapixel Nikon digital SLR has not much more than half the megapixels but will deliever truly superior image quality. And even with "only" 6 megapixels, I can get 11x17 sized prints with no visible grain in the image. So the extra 4 megapixels is not needed and if it comes at the expense of image quality at higher ISO's or slower shutter speeds, it would actually be undesireable.

In the same way WOB numbers really do a poor job of reflecting the qualitative performance of the regulator and above a certain point, it is the qualitative measures that really count. In some cases, the "good" numbers are produced with a side effect of unnatural breathing performance that negatively impacts those very important qualitative measures.

The reality is that the average customer understands quantitative data in ads, and qualitative research is much harder to do well, so the marketing people focus on quantitative numbers and WOB fits the bill perfectly - even if it really gives little useful information.

The problem is that the marketing department drives the engineering department in many companies and standards like the EN 250 standards make it even worse. I tend to embrace diversity in all its forms, but I really don't care whether my regulator meets a European standard, especially when those standards are turning regs into mediocre performing clones of one another that qualitatively perform at a lower standard than their predecessors did 15-20 years ago. In my opinion, regulator development has flatlined over the last 10-15 years and I think the rush by the rest of the world to accept european norms to be able to sell in the european market are largely responsible.

Another great post, DA. Thanks for sharing your knowledge and insights here.