And this goes back to the issue we were talking about in
your other thread comparing the 1" 8-track at 15 or 30ips and what would sound "better" and the answer was/is (AFAIC) you need to let you ears judge and talk to others about their experience
with that deck.
Yes, 30ips presents more oxide to the head for a given amount of time and a given track width, but the bump to 30ips shifts the response curve of the deck which could do bad things or good things or no-things to the sound, and likely a mix of those three and ultimately your ears will have to judge how that fits with the setup of the transport and electronics, the tape type and most importantly (again AFAIC)
the source material.
Again I refer to the
Endino article...really, really addresses your questions...
And don't think that
because you tracked at a certain speed format that that drives how you master! The two aren't tied IMHO. You can see by the Endino graphs that if you tracked to
the Studer A80 MkII 2" 24-track (you have one of those sitting around right??
) at 30ips (which you may like because the HF response is WAY flatter than at 15ips and the LF response is still good at 30ips with a -3 point at about 40Hz), you wouldn't necessarily want to master to your APR-5000 1/2" half-track (ya got one of those too
right??? 
) at 30ips
just because you tracked at 30ips! That deck presents a
really nice flat response at 15ips...SHEESH!! Better than +1/-0.5dB from 30Hz to 20kHz, and only -1.5 at 20Hz!!!
And that is at 15ips. By comparison you can look at the APR-5000 response curve at 30ips. All of the sudden you've introduced a +1.5 head-bump at about 60Hz (not
bad mind you...just not as flat in comparison to the 15ips curve), and your LF -3 knee-point is at about 28Hz (also
not bad...AT ALL! Just when you compare it to what the deck can do at 15ips it looks "better" to my eyes, and I'd pursue that
based on what Endino inferred about how it sounds at 15ips. Make sense?) Look at what he said about the MS-16. I have indeed seen a number of those that have been modded to run at 30ips. Why? Well, based on the iformation in the sales listing I'm thinking it was because somebody was convinced "that's pro dude"...but Endino, who is clearly pulling no punches in how he feels about the different decks he tested (i.e. look at what he says about the ATR60-16 at 30ips), has some nice things to say about the MS-16 at 15ips, and the curve shows why. You are free to do whatever you want based on the sound you are looking for. That ATR60-16 at 30ips might just be the ticket for the project...who knows? It may sound good to your ears and nobody can or should try to take that away from you. Hey, I'm looking forward to how my Ampex 440-8 may sound with a CCIR eq curve for drums and bass even though there may be a healthy head-bump still...the curve doesn't tell you everything about how the deck sounds with complex audio, but it gives you a point of relativity. So do what you want. Don't let anybody tell you what's "right" or "pro" or "proper"...its a mistake to do so...try it out and talk to others in a way that spells out where you are coming from and where you want to go and do the "wrong" thing if it fits you,
but my admonission is that you go forth in that direction with some strategic education about what you are doing, rather than "because its 'better'".
This same argument applies to the principle of using +9 tape on a deck with electronics that are designed around +6 tape. Just because the tape has a higher rated output does not mean it is necessary/will sound better/will
work with a particular deck. And just because you are running +9 tape does not mean you have to set the deck up at 500nWb/m and bury the meters on every track either! I'm going to
try +9 tape on the 440-8 because I have an opportunity for a reel in trade, but I'm likely to set the deck up at "0" @ 250nWb/m or possibly even 185 and see how it goes...experts tell me it'll bias at higher levels but the erase ratio may not be able to keep up...so that's one of those times it helps to have some background information so you can make strategic decisions about what you are going to do.
I'm off my soap box/rant now and Robertobly this is not meant to be pointed at you so I hope you don't take it that way. This is a really great topic and I'm glad you've brought up both of these threads. I hope the links to past stuff is helpful for somebody. I know it has been helpful for me to revisit this stuff.
