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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's avatar
hilde45 OP
4,773 posts
 
@cal3713 Good points. The only other reason they might have put the feature in, besides the one you state, is that customers demanded it, despite the effect on sound quality. What I'd like to find out from them, is whether they believe they've pulled it off in a way that makes a minimal/negligible impact. And you're right that I don't want to go that crazy with DIY audio! I'm just trying to determine whether this feature is important — all other things being equal — contingent upon the effect is on sound quality.

@djones51 I suspected they'd say something defending their product (of course!) but I didn't know what they'd specifically say. Also, I am a charitable guy; they might have had some additional reasons I had not considered. Instead, they made an argument based on not messing with the speaker's design, as if every speaker's design would contribute to all rooms, uses, components, etc. If folks here are right, that is specious reasoning. The fact they committed that to print tells me something (maybe not much) about the company more generally. It helps with my purchasing decision.
cal3713's avatar
cal3713
1,421 posts
 
I don't think PSA's argument is specious at all.  When you change the crossover point, you really are arguing with the speaker designer.  Not that the Parasound feature is likely to be used for anything other than sub integration.  It's also a rare feature, so I don't think PSA was being defensive at all.  Most subs are active and come with a built in crossover that allows you to integrate with your main speakers, so sending them a full signal is normal and expected.  The passive ones expect you to pair them with a subwoofer amplifier that also has gain and crossover controls, also expecting a full range signal.  In both of those cases skipping that circuitry (which is probably coming from a $200 plate amp) and relying on the Parasound probably will improve the crossover quality.
douglas_schroeder
3,281 posts
 
Some horrible advice given by millercarbon. Will lead to worse results. 
WRONG:
Look for Integrated first
Ignore specs, i.e. wpc
Average cost of system elements

Follow that advice and odds of attaining mediocre sound are high.  :(

DO:
Separates
X-over in sub
Pay attention holistically to specs
NOT average costs! 40% on speakers,  10% on cables, rest on electronics ZERO on tweaks.

OBVIOUSLY system components synergy/matching is critical. 

Not interested in arguing my advice. Pick your authority,  and get your results. :)
hilde45's avatar
hilde45 OP
4,773 posts
 
Ok, well I’m confused, then. Consider:

Fact: Parasound offers something that changes the crossover point for the speaker design. They argue (and some here agree) that’s overall beneficial for sound because it reduces burden placed on speakers and amp while improving the integration of sub, speakers, and room.

Fact: PS Audio asserts they don’t offer that feature because it speaker crossover design shouldn’t be interfered with and that this adds circuitry that harms the overall sound.

Dilemma: either Parasound’s feature is beneficial to the achievement of audio quality *overall* sound or it’s not.

(a) If it IS helpful, then it IS ok to interfere with the crossover of the main speakers and PS Audio’s argument is wrong.

(b) If it IS NOT helpful, then it is NOT ok to add circuitry and interfere with the crossover of the main speakers and PS Audio’s argument is right.

If (a) is true, the PS Audio’s reasoning is specious.
If (b) is true, Parasound’s feature is detrimental to overall sound and shouldn’t have been included in their product.

There is another alternative:

(c) The question doesn’t really matter very much, and while people make design choices and then argue for them, these are tantamount to cosmetic differences and the differences highlighted are more marketing than engineering arguments. I’ve made a mountain out of a molehill. In which case, the answer would be (as I think was said by least one person above): "Fuggedaboutit."

djones51
4,947 posts
 
I looked up your sub the Rel 328 and was wondering how do you connect it now? According to the manual you should use the speakon connector on the sub  and connect to your amps speaker binding posts in which case you wouldn't use the preamp crossover. It shows other ways of connecting but says this way is best for 2 channel system. PS Audio suggestion makes sense if you're not using a subwoofer but if you are a crossover is going to come into play somewhere and is not really something you see  a lot on 2 channel stereo preamps anymore it's  not a specious argument. The Parasound would give you the choice of using the subwoofer connected with the sub out and using the preamp to control the crossover and compare with the way Rel suggests but it doesn't look like it's a feature you really need but for some it could be useful as they wouldn't have to buy another component if they wanted to set crossovers so it is beneficial in certain cases. For example if I was using a small bookshelf speaker that only went down to 48hz without using a subwoofer  I would set the high pass on the Parasound say to 45hz making it easier on the amp and speaker since the speaker isn't going that low anyway you're not interfering with the speakers crossover. 
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