Hi-pass filter for NX-Otica - questions

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Edward4

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Hi-pass filter for NX-Otica - questions
« on: 17 Sep 2024, 08:10 pm »
Hi everyone,

So I recently wanted to upgrade my subwoofer, I saw that the GR-Research sub kits were sort of on backorder for a couple months, and (for now) I purchased one used Rhythmic servo sub. I also tried following Mr Richie's advice for building a simple high-pass filter for my 50k-Ohm amp, using a Dueland 0.047uF capacitor, and running a low-level cord from my preamp to the sub. I believe this gives a -3dB down at about 70Hz.

It seems to work okay - I haven't screwed anything up. Yes, I think there is less of a low end when I turn off the sub and switch the left-right dial all the way to that side. So that's good.

I guess I have several questions...

1) First of all, can a home audio system ever duplicate the sound of a massive symphony orchestra with vast numbers of instruments playing different things all at once? I assume the answer is: no way, that simply can't happen, but it's an industry secret that nobody tells you. Now, I've never heard a well-put-together $100K system for comparison at a show or whatever, just my own system. My system sounds great for small numbers of musicians, but if I try to play something complex like a symphony (or O Fortuna by Carl Orff) and turn up the volume a bit, it mostly turns to mush - it sounds loud but I can't really pick out any of the instruments too clearly, except for some of the most obvious details. Is this pretty standard, even for $100k systems? Or can this situation be improved a lot if a person dials in their subwoofer / high-pass filter settings, with a lot of patience and tweaking and experimentation?

Right? Building a home audio system seems a bit like playing basketball. Once you've seen Michael Jordan or Larry Bird do some amazing moves, all of a sudden you're like holy moly, now I know what is possible! Now I'm inspired, now I can set my sights higher, now I'm motivated to improve my game! But if you lived in a remote part of Alaska with no TV and no internet, you might not know what is possible, you might have really low standards.

So that's my main question.

2) Another question has to do with targeted roll-off numbers. For a tower system like NX-Otica, should the targeted -3dB rolloff frequency be around 40-60Hz? Or should a person just experiment and see what works best? I'm wondering if the woofers on the NX-Otica are trying to play many, many octaves of sounds. If I divert a single octave to the subwoofer(s), does that still leave the woofers in the tower speakers being overworked?

3) If anyone had success tinkering with high-pass filters, what did you find worked best, in terms of crossover frequencies & testing procedures?

Thank you for your help!!!

Also, thank you to Danny Richie for giving the world some honest, accurate advice about how to setup audio systems. What a breath of fresh air. I tend not to trust people but so far all of Mr. Richie's advice has been very helpful.

Edward4

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Re: Hi-pass filter for NX-Otica - questions
« Reply #1 on: 17 Sep 2024, 08:22 pm »
I guess I should add that yes, I've tweaked a lot of other things in this system. At this point I think the weakest link might be the speakers setup... but I'm just guessing here.

... not that there's anything wrong with NX-Oticas, but I mean, when a symphony orchestra does its monthly payroll and pays 100 musicians to come to work and play their instruments during performances, that's a lot of $$$$$ they are shelling out to create a certain sound, right? That's a lot of freaking money they are paying. For me to think I can duplicate a symphony orchestra with all those musicians, with cymbals crashes and those massive drums and and complex harmonies - it's probably just not possible to make it sound 100% realistic like I'm in the room with those musicians, I presume, using a dozen speaker drivers and 3-4 crossover points...?

I assume audio reproduction is just like any sort of engineering problem - if you increase the "load" enough on a system, eventually it will fail somewhere, or reveal its weaknesses somewhere. With audio, the "load" I assume means turning up the volume and increasing the complexity of the sound you are trying to reproduce. Eventually, each system will show its limitations...

Early B.

Re: Hi-pass filter for NX-Otica - questions
« Reply #2 on: 17 Sep 2024, 10:40 pm »
For #1, you answered your own question. A live performance compared to a home audio system is like attending a pro basketball game vs. watching it on TV. Some TVs are bigger and better than others; no TV will ever get it right, but that's not the goal. The goal is to get your home audio system to sound better than a live event, and that's entirely plausible because you have more control of what you want to hear.
 

Danny Richie

Re: Hi-pass filter for NX-Otica - questions
« Reply #3 on: 18 Sep 2024, 10:47 pm »
Quote
1) First of all, can a home audio system ever duplicate the sound of a massive symphony orchestra with vast numbers of instruments playing different things all at once? I assume the answer is: no way, that simply can't happen, but it's an industry secret that nobody tells you. Now, I've never heard a well-put-together $100K system for comparison at a show or whatever, just my own system. My system sounds great for small numbers of musicians, but if I try to play something complex like a symphony (or O Fortuna by Carl Orff) and turn up the volume a bit, it mostly turns to mush - it sounds loud but I can't really pick out any of the instruments too clearly, except for some of the most obvious details. Is this pretty standard, even for $100k systems? Or can this situation be improved a lot if a person dials in their subwoofer / high-pass filter settings, with a lot of patience and tweaking and experimentation?

Our NX Series models can easily separate the instruments in the orchestra and play to realistic levels.

Hobbs (right hand man here at GR) went with my wife and I to the symphony last year when our local symphony orchestra covered about 12 songs (pieces) from John Williams. We were seated in area just right of center and about 1/3rd of the way to the front. A main take away was that we are trying to playback symphonic pieces much louder than the actual orchestra played them. Playing them back at realistic levels was easy. 

Quote
Right? Building a home audio system seems a bit like playing basketball. Once you've seen Michael Jordan or Larry Bird do some amazing moves, all of a sudden you're like holy moly, now I know what is possible! Now I'm inspired, now I can set my sights higher, now I'm motivated to improve my game! But if you lived in a remote part of Alaska with no TV and no internet, you might not know what is possible, you might have really low standards.

Yeah, we're kind of spoiled over here.

Quote
2) Another question has to do with targeted roll-off numbers. For a tower system like NX-Otica, should the targeted -3dB rolloff frequency be around 40-60Hz? Or should a person just experiment and see what works best? I'm wondering if the woofers on the NX-Otica are trying to play many, many octaves of sounds. If I divert a single octave to the subwoofer(s), does that still leave the woofers in the tower speakers being overworked?

A -3db in that area is ideal. Even if you are not pulling away output by knocking off the first octave, you are still reliving those drivers of seeing or trying to play them. Just knocking off the first octave nearly doubles the headroom. 

Quote
3) If anyone had success tinkering with high-pass filters, what did you find worked best, in terms of crossover frequencies & testing procedures?

A single inline cap in the right value works great. https://gr-research.com/hi-pass-filters/

Tyson

Re: Hi-pass filter for NX-Otica - questions
« Reply #4 on: 19 Sep 2024, 01:52 am »
I go to the symphony quite often.  A top flight speaker like the NX-Oticas will get you 85% of the way there.  At least in my setup, they are absolutely incredible at detail, tone, soundstage and clarity. 

If you are experiencing things turning to mush as the music scales, then I'd look to room treatments and speaker placement as a way to fix that.  What room treatments do you have now?  And what is your speaker location like?

jmimac351

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Re: Hi-pass filter for NX-Otica - questions
« Reply #5 on: 19 Sep 2024, 02:25 am »

A -3db in that area is ideal. Even if you are not pulling away output by knocking off the first octave, you are still reliving those drivers of seeing or trying to play them. Just knocking off the first octave nearly doubles the headroom. 

This is interesting, so you recommend using a high pass even for NX-Otica?  If something like a 60Hz high pass doubles the headroom... I guess that would mean they would be moving as little as the woofers do on the NX-Treme? 

I remember listening to your NX-Treme and you told me to go look at the woofers while it was playing at a solid volume.  They were barely moving... probably why I kept saying the sound was "effortless" - it was.

Edward4

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Re: Hi-pass filter for NX-Otica - questions
« Reply #6 on: 19 Sep 2024, 03:19 pm »
Hi everyone, wow, I just noticed all the replies. Yes, interesting comments.

I love John Williams!

Yes, I've been trying to listen to the NX-Oticas from both the front and the rear, not in a dedicated listening room but in an AV island next to a TV, in the middle of an open floor plan between multiple areas, with an eight-foot ceiling, so I've recently been adding additional NoRez to the back, and also starting to work more with room reflections. The reflections were definitely causing some of the "smearing" effect, especially if I turn up the volume slightly (?). Or maybe I need to rethink the position of the speakers altogether.

Yes, going to listen to a symphony live is something I haven't done in a long time. It does tend to be kind of a calm, gentlemanly experience, but I think people like Beethoven probably wanted it to be somewhat overwhelming, aurally speaking, like a modern day rock concert. Hearing a pipe organ live in a church is something else I haven't done in a long time, but again I think it's supposed to be a bit overwhelming. The individual is supposed to feel small, I think, and the sound is supposed to create a feeling of awe. Not hearing damage, but you know. It's supposed to wake up the little old ladies, etc... Of course in my home most of the time it doesn't need to be loud, but once in a while it's fun to have that ability.

I also ordered a smaller-Farad capacitor to experiment with, a couple days ago, for the high-pass filter. I think this will raise the rolloff point a bit. But maybe this is not the issue, maybe the room reflections are by far the biggest issue. Maybe way, way further down on the list is the signal I'm feeding into the amp from my turntable stylus, etc. Will need to experiment with that.

And some day I would like to visit a show with all these 100K systems, & visit Danny & Hobbs if possible.

Thanks for all the suggestions.

Tyson

Re: Hi-pass filter for NX-Otica - questions
« Reply #7 on: 19 Sep 2024, 04:34 pm »
I would recommend treating the room pretty heavily.  GIK has these things called "Art Panels" where they will print photos of art (or whatever you want) on the panels to be hung on the walls.  This will address most of the problem you are hearing. 

Re: speaker placement, that's also super important.  I'd recommend running through the LOTS setup that Ron demonstrates here:

https://www.youtube.com/watch?v=CyTkwkK8ON0

Re: the orchestra and volume, it really depends on where you sit.  If you sit mid-hall or farther back, then the sound is not overwhelming.  If you sit closer to the orchestra, then it's much louder.  And in pieces like Bruckner/Mahler/Shostakovich it can be overwhelming.