Question on the Integra DHC 40.2 Pre-Pro

Is anyone intimately familiar with this unit? Question has to do with the external manual tone control button. The manual states that this only controls bass response in the front main speakers and not in the subs. How could this be? Most other HT receivers and pre-pros with an external tone control adjusts the bass in the entire system including the subs. Why would it only control the main speakers? I find this feature very useful on my current Rotel surround processor but it's 10 years old now and I'm looking to upgrade. I can't afford a brand new Rotel processor but a new the Integra DHC 40.2 is within my budget. I like having one button to control bass in all speakers. THANKS.
I use two Integra AVRs (not the 40.2,tho) and an Onkyo pre-pro in various rooms in my home. I've never used the tone controls on any of the units because I let Audyssey do the set up and have never found the need to tweak further - other than reducing overall bass level on one occasion. That simply involved dialing the subwoofer down via its dedicated level control.

If you use tone controls, I assume that they were limited to L & R without the sub because you can vary the level of the sub at the sub itself - per my case, above.

Marty, thanks for the explanation. I guess I need to learn much more about Audyssey as I've never had that function. I've always done loudspeaker balancing myself using a dB meter but there must be much more to Audyssey than just the initial setup. SOunds like it adjusts and compensates real time. Yes I can adjust at the subs but I have two and it's just so much more convenient to go to one simple control to adjust LFE's and bass from song to song. FYI I called Integra technial support today just out of curiosity and the tech advised that the tone control on the unit adjusts LFE and bass to wherever it is being sent and produced so that must mean the subwoofers as well. I plan to audition this unit soon and will find out then !! Thanks.

In my view, Audyssey is a absolute game changer. If this is your first go-round with it, I think you may be amazed. Subwoofer integration is seamless and clarity in the lower registers is eye (ear?) opening. Not everyone agrees with me - so you have to make the call for yourself - but I'm 100% sold.

Marty, thanks again. Well with your invaluable input, I purchased the DHC 40.2 and should have it next week. THANKS again and I'll comment on it once it's all set up and percolating. I'm studying the manual now in advance. Wow how can one machine have this many features and functions? Too many !!