Is Parasound on to something? Or, How important is crossover management in preamps?


How important is crossover management in mid-fi receiver?

I auditioned Parasound separates yesterday — P6 and A23+ and the dealer emphasized how useful it would be to be able to control the crossover *both* for the subwoofer (I have a Rel 328) and the bookshelves (TBD, but I'm looking at Dynaudios and Salk WOW1's). Not many preamps have this, and I'm wondering how important it is. I'm also quite interested in PS Audio's separates (Stellar Gaincell + S300) but they do not have these, nor do they have tone controls.

So how valuable is Parasound's controls? What is the significance (positive or negative) control over the crossover — especially of the *main* speakers themselves? The positive, I read, is that it (a) allows mains to do a more precise job by relieving them of the burden of the bottom end, and (b) it increase the efficacy of the power amp in driving the mains. Is there a negative? Is there something "improper" about limiting the demands on mains, especially given their designed frequency range?

As you can see, the answer to this question helps determine whether Parasound has a major value-adding feature in these crossover controls.

Obviously, at the end of the day, auditioning pre's and poweramps (or integrateds) is crucial, as is match to speakers, etc. But if this feature is very important for fitting sub and mains together — and fitting speakers to room environments — then it will help me weigh the Parasound or any other preamp with this feature.

P.S. To those who keep seeing my newbie questions, I hope they're not irksome. I'm posting so often because I'm researching purchases for a whole system, of some cost, and so I'm really digging into these questions about all aspects. And I'm having a blast.
128x128hilde45
@hilde45 & @lukaszwk  Agreed that people with an axe to grind hurt the forums... disagreed that this makes the place worthless.  I've learned so much here.  If you hang out enough you can get a sense of who to trust... and learn a lot in the process.  

As a shortcut judgment...  always believe @almarg .  And if you click on a username you can go look at their last X posts and see what you think about their recent contributions.  
I do enjoy reading certain individual’s posts, people with actual engineering decree and knowledge surpassing 99.99% of people here, like Atmasphere’s posts but people like that are few and far in between. This places has slowly been losing its luster and usefulness, for me at least. But to each his own. If you can truly be selective as to who you listen to, it can still be a useful place at times. But I think I’ve had it. At least for awhile.
@almarg and @douglas_schroeder and all,

I never complained about axes to grind; I am just trying to get straight. So, I emailed Jim Salk about this question, giving him all the information about my sub, which amps, etc. The short version of his answer is that crossovers for the main speakers can help. Here’s Jim (I hope it’s ok that I’m quoting him):

"I normally let me speakers run full range and bring the sub up under them. But, of course, I am always using much larger speakers. In the case of the WOW1’s, they are down 3db at 48Hz. So I would set the subwoofer crossover to 55 or 60Hz if you wanted to play them full range.

But there is a case that can be made to use a preamp/processor to set the crossover higher. For example, most home theater processors would probably define the WOW1’s as being a “small” speaker and use 80Hz as the crossover point, running the sub with no crossover (all pass) since the processor will only send audio under 80Hz to the sub. The benefit of this is increased power handling. The deeper a speaker plays, the more cone movement is required. The cone can only move so far (XMAX) before it bottoms out. But when eliminating some of the bass duties, not as much cone movement is required so it can play louder without bottoming out.

Of the two, I would probably opt for the latter approach since it would allow your system to play louder without bottoming out the WOW1 woofers."

@cal3713 Thank you kindly for the nice words.  I always value and enjoy your posts as well.

@hilde45, Excellent answer by Mr. Salk, as Doug had prognosticated.  I would add that even if a woofer does not bottom out, as it approaches that condition the sonics of a speaker are likely to be adversely affected in various ways.  And that figures to be especially true in the case of the WOW1, given that its woofer is undoubtedly handling just about the entire midrange, as well as the bass.  (The woofer it uses has a recommended frequency range of 60 Hz to 3500 Hz; the tweeter it uses has a recommended frequency range of 2.5 kHz to 25 kHz).  

Also, if you were to go with a different speaker now or in the future, as I mentioned earlier the P6 would provide you with the flexibility of being able to conveniently remove its high pass filter from the signal path, via the switch it provides on its rear panel for that purpose.  

Good luck.  Regards,
--Al