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How does high-pass filter requirement affect system decisions?

I've been thinking about my Ayre AX-7e that drives my Vandersteen Quattro CTs (the AX-7e had the required high-pass filter installed by Ayre). Other than the obvious, how does that filter affect system choices?

For example, I'd assume the current-delivery requirements are reduced, the need to damp back-EMF is reduced, and perhaps the speaker cable characteristics change (since they are not carrying as much low-frequency, high-current information). Are massively overbuilt amplifiers really necessarily to bring out the best from the Quatros?
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Showing 5 responses by nrenter

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nrenter OP
765 posts
 
I think it gives you a lot more flexibility for experimentation. 

I'm very happy with my AX-7e. Of course, I'm interested what an Ayre upgrade would do, but I think $12k of new music would bring more satisfaction than $12k of new hardware. 

I do feel like my break-in process took much longer than expected (assuming predominantly the components downstream of the high-pass filter). When I bought the Quatros, I also bought Pangea 9-gauge power cables for each speaker, 2 pair of Audioquest CV-8 speaker cables, Audioquest Colorado XLR cables for all my sources (along with Pangea power cables) and an Ayre L-5xe power conditioner. Oh, and the new crossover capacitors dropped into the AX-7e. These probably all play a factor. 

It's interesting how loudly you can play the system without any sense of strain. 
nrenter's avatar
nrenter OP
765 posts
 
@goheelz, the taper on the IEC end of the Pangea Audio AC 9 MKII power cable allows it to fit easily. The downside to this cable is that it's very heavy and not very flexible.
nrenter's avatar
nrenter OP
765 posts
 
@randyhat given the rolloff required for the powered subs in the Quatros, the difference of a few 10's of Watts may not be a significant factor. I'm over in Flower Mound (and I set up my Quatro CTs on my own). Once you know the "tricks" it's pretty easy to do. 

nrenter's avatar
nrenter OP
765 posts
 
No problem with the stock cables, per-se. I'm sure they successfully supply power. Is there an audible difference between the stock power cabled and the Pangea? Don't know. But the Pangea AC 9 MKII sure LOOK bad-ass, and isn't that what really matters? They're like a firehose connected to the wall. I could fend off a band of ninjas with a few swings of a 1.5 meter cable. Plus, I've blown $135 on dumber things. The AC-14SE cables are MUCH more flexible, and look a lot better than the stock cables. I have AC-14SE power cables connected to the rest of my components.
nrenter's avatar
nrenter OP
765 posts
 

For anyone following this thread, I did ask Richard variation of this question. He posted his response to the “Ask Richard” section of the Vandersteen website:

Nicholas (1/13/17): Richard, I miss the regular updates to the "Ask Richard" section! It gave me a reason to visit the Vandersteen website early and often. BTW...really loving my Quatro CTs (John @ Audio Connection is awesome).. I've got a freakishly-flat listening position in-room response down to 24 Hz (falls off a bit at 20 Hz). I'm driving it with an Ayre AX-7e w/ factory installed filters. When I started typing this, I didn't really have a question (other than asking to bring back the "Ask Richard" section...but now that I think about it... Is it possible to quantify the potential performance improvement of an amplifier when the input signal is attenuated by a first-order crossover -3dB @ 100 Hz? Intuitively, the amp will have less current requirements into the load (based on the attenuated input signal below 100 Hz). What decisions did you make when designing the M7-HPA that would differ than someone designing a full-range amp (with respect to the input signal and load demand characteristics)? Glad to be part of the Vandersteen family. - Nicholas Renter

HELLO NICHOLAS, THE FAQ IS STILL VERY MUCH IN PLAY BUT WITH SO MANY ARCHIVED NOT MANY QUESTIONS ARE NEW SO I DON’T ANSWER QUESTIONS WHICH ALREADY HAVE BEEN ANSWERED (NOT DUTCH EFFICIENT). IT IS HARD TO QUANTIFY THE IMPROVEMENTS HEARD WHEN THE POWER SUPPLY IS HELPED BY A HIGH-PASS AT 100Hz. YOUR DEALER COULD DEMONSTRATE IT TO YOU BY INSERTING THE HIGH-PASS AND THEN REMOVING IT. IT IS SUBSTANTIAL BUT LIMITED BY HELPING THE POWER SUPPY ONLY. THE M7-HPA IS A VERY DIFFERENT STORY AND ITS ADVANTAGES ARE HUGE BECAUSE THE CIRCUIT AND POWER SUPPLY ARE OPTIMIZED FOR HIGH-PASS ONLY. MANY FEATURES HAVE BEEN INCLUDED WHICH COULD NOT BE IF THE AMPLIFIER WERE TO BE FULL-RANGE. I WILL GIVE YOU ONE EXAMPLE TO HOLD YOU UNTIL WE GET THE WHITE PAPER. A FULL-RANGE AMPLIFIER HAS TO HAVE MULTIPLE OUTPUT DEVICES IN ORDER TO HANDLE THE CURRENT NEEDED FOR THE WOOFERS. MULTIPLE OUTPUT DEVICES (TUBE OR SOLID STATE) SMEAR EACH OTHER SLIGHTLY BECAUSE THEY CANNOT BE EXACTLY THE SAME. IN THE M7-HPA VERY FEW OUTPUT DEVICES ARE NEEDED AND NO EMITTER RESISTORS ARE USED CAUSING NOTICABLE IMPROVEMENT IN DYNAMICS AND TRANSPARENCY.


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