Incorporating MiniDSP With Audyssey XT32

[Pogre]

Definition of LFE:

If you aggressively high pass filtered the signal to your mains at 40Hz or so, that might work, but HT LFE content can be stupid loud and low from a music standpoint. For example, the powerful strikes of the tympani of Also Sprach Zarathustra (Theme to 2001: A Space Odyssey) is no lower than 60Hz. I'm betting your towers would be phenomenal with these drums at a spirited volume!
But if you feed them the LFE from "Lord of the Rings" at an engaging volume level, you will push them beyond their limits.

This begs the question of whether Ed's main concern was sending LFE content to the Ultras or if it was isolating the woofer section and applying miniDSP to it.

So, I think it'd be reasonable to use them full range and manage the bass using the miniDSP (but without adding the LFE signal). I would be slow to do much with miniDSP in the higher frequencies and let Audyssey manage that, but in the lower frequencies, it makes sense that your towers are having the normal issues of low frequency room effects. Whether you isolate the woofer section or simply apply miniDSP to the lower frequencies doesn't seem like it'd matter much, but I like the idea of knowing you cannot impact the higher frequencies after you separate them.

From what I've read, the low end of those towers is very nice and it seems a crime to cross them at 100HZ (IIRC). It also makes sense that room modes beyond what Audyssey can easily handle may be the reason that your curves look best when the towers are crossed so high.

I would be tempted to start fresh, tuning your system without the subs and with the woofer sections on the miniDSP, just to see how good you can get the towers to sound (with music) and what you learn from it!

Actually, I just found an old (2012) article that does a great job of discussing much of what you are doing/considering!
https://www.soundandvision.com/content/schroeder-frequency-show-and-tell-part-1
From part two:


Edit: I was piddling around and had this post sitting on a back burner for several hours. I am not posting this as a direct contradiction of PENG's (or LovinHD's) posts (which I did niot read until after I posted this. I am more throwing out food for thought ... I don't know enough about this to argue what you should do!

Thanks Kurt! That is interesting and right in line with what I'm thinking about. I would only be eq'ing from 150Hz or so and down (not lfe), without ever touching the upper half of the towers at all.

HD and Peng, I also appreciate your replies as this is not something I want to just start and arbitrarily start applying filters and you guys are driving that home to me. I need it from all sides. I'll make sure I can at least comprehend what I'm thinking about before I touch anything at all.

 

[Pogre]

This! That tower does not have the same protection circuitry built in to it as a dedicated subwoofer would. So when users start boosting below the resonant frequency of the driver in order to achieve an idealized measurement, there is no way to protect the driver from damage.

@Pogre could provide a basic map of the dimensions of his space like NINAudio did and someone wanting to offer help might aid in predicting those room modes in order to make better use of those very capable subs in order to drive the standing waves....

Let's say I manage to get accurate measurements and determine that my room modes are at 75hz and 105hz. What would I do then?

 

[TheWarrior]

Let's say I manage to get accurate measurements and determine that my room modes are at 75hz and 105hz. What would I do then?

Everything matters. If you understand that everything matters, then you understand why I can't possibly provide a useful answer to your question.

You'll notice I asked NINAudio more questions and didn't offer any solutions, but was able to identify starting points where two subs may be able to drive the modes/stand waves - boundary intersections where modes stacked up on each other. Two subs may not be able to solve all of the problems, but changing their locations and providing them the right filters should be more effective than what has been tried in both situations.

I'm here offering help, but you've gotta give me information to work with!

 

[Pogre]

Everything matters. If you understand that everything matters, then you understand why I can't possibly provide a useful answer to your question.

You'll notice I asked NINAudio more questions and didn't offer any solutions, but was able to identify starting points where two subs may be able to drive the modes/stand waves - boundary intersections where modes stacked up on each other. Two subs may not be able to solve all of the problems, but changing their locations and providing them the right filters should be more effective than what has been tried in both situations.

I'm here offering help, but you've gotta give me information to work with!

I appreciate the offer, but before I even attempt to go through the task of measuring my room(s) I'm curious what the next step would be. Let's assume my modes (big dips) are at 75hz and 105hz. What would I do then? I can't really move my subs around.

 

[ATLAudio]

Let's say I manage to get accurate measurements and determine that my room modes are at 75hz and 105hz. What would I do then?

Don't you have volumes of books to go read!

Anyways, this also begs the following questions;

1. You can arrive at a proper conclusion by manually measuring dimensions in your room and using a simple formula

2. There's not an easier and more accurate way to do it using REW, a lot of which (but not all) has already been discussed, and flippantly dismissed because of meaningless word salads and gish gallop.

 

[TheWarrior]

I appreciate the offer, but before I even attempt to go through the task of measuring my room(s) I'm curious what the next step would be. Let's assume my modes are at 75hz and 105hz. What would I do then?

Are those length, width, or height modes? Are they measuring as axial or even tangential modes? (Oblique rarely affect small rooms) What inputs have been made to the system thus far? What is the LFE crossover? What is the distance of the listener to the nearest boundaries? A map of your room with baseline acoustic measurements will answer those questions, allowing me to answer your question.

It's real simple fella's, you're not in control, the room is. So you need to measure it in order to know how to influence it.

 

[TheWarrior]

Don't you have volumes of books to go read!

Anyways, this also begs the following questions;

1. You can arrive at a proper conclusion by manually measuring dimensions in your room and using a simple formula

2. There's not an easier and more accurate way to do it using REW, a lot of which (but not all) has already been discussed, and flippantly dismissed because of meaningless word salads and gish gallop.

Sorry, what questions?

 

[Pogre]

Are those length, width, or height modes? Are they measuring as axial or even tangential modes? (Oblique rarely affect small rooms) What inputs have been made to the system thus far? What is the LFE crossover? What is the distance of the listener to the nearest boundaries? A map of your room with baseline acoustic measurements will answer those questions, allowing me to answer your question.

It's real simple fella's, you're not in control, the room is. So you need to measure it in order to know how to influence it.

Sigh.

Alex, if you could break the process down in simple lay terms and explain what I would do for any predicted room modes outside of eq I might start considering it. As it is, you seem either unwilling or unable to explain it to me.

 

[ATLAudio]

Or dismissing because of one’s own lack of reading comprehension, and or personal incredulity.

 

[Pogre]

@TheWarrior, let's say I measure everything in my room and you predict all of my room modes. Then I measure with rew and the graph correlates with the predictions. What would I do differently outside of eq'ing the highs and lows? My subs and towers are pretty much stuck where they are.

 

[agarwalro]

1. You can arrive at a proper conclusion by manually measuring dimensions in your room and using a simple formula

Yes. The math brings one close to the correlated observations. Further, the math accords understanding not elucidated by prodigious measurements.

2. There's not an easier and more accurate way to do it using REW,

Its a matter of preferred approach. Start with the math and lay out room to avoid pitfalls or arrange room and optimize by trial and error. Warrior is a proponent of the former, you the latter. There really is no one saying anything fundamentally incorrect.

a lot of which (but not all) has already been discussed, and flippantly dismissed because of meaningless word salads and gish gallop.

I'm yet to catch the flippant dismissal. If anything your passive aggressive attacks on Warrior, even on completely unrelated threads, are getting insufferable. His over exuberant Toole fanboy tendency and verbose posting style are no cause for ramble rousing.

 

[agarwalro]

Sigh.

Alex, if you could break the process down in simple lay terms and explain what I would do for any predicted room modes outside of eq I might start considering it. As it is, you seem either unwilling or unable to explain it to me.

You can't EQ down a peak corresponding with a strong mode. Conversely, you can pump inordinate power into a dip/null from room modes and it won't do anything.

The analysis will help you select a crossover such that a mode from the sub location can be countered by the mains and vice versa.

 

[agarwalro]

@TheWarrior, let's say I measure everything in my room and you predict all of my room modes. Then I measure with rew and the graph correlates with the predictions. What would I do differently outside of eq'ing the highs and lows? My subs and towers are pretty much stuck where they are.

Since you room layout is fixed, you'll know when to stop optimizing since some artifacts will never be removed. At that point, you can start focusing on absorbing vs diffusing panels (at 1st and 2nd reflection points) to achieve the desired balance between imaging and soundstage.

 

[ATLAudio]

@agarwalro

Room mode measurement provides information which can be meaningful, but in rooms as complex and fixed as Pogre’s it seems like it’d just add to the confusion. My approach is to use REW tools, like the waterfalls which you suggested, which warrior flippantly (IMPO) dismissed with a text wall of mostly irrelevant links (your words). Or other REW tools which can give you an idea of the most problematic modes, and can give a very good solution to them. I’ve tried several, several times how I use these things to Warrior, and he would just beat me up with his (incorrect) definitive assumptions, and condescending Toole fanboyish approach. Bottom-line; it all depends on one’s goals, expectations, and how ideal one’s situation is.

Moreover, and he can tell me I’m wrong, but I believe that Pogre has asked the same basic question several times without an answer to his satisfaction, yet Warrior continues to brow beat... In a sense, this is trolling.

 

[Pogre]

Since you room layout is fixed, you'll know when to stop optimizing since some artifacts will never be removed. At that point, you can start focusing on absorbing vs diffusing panels (at 1st and 2nd reflection points) to achieve the desired balance between imaging and soundstage.

If I apply up to 6db +/- to a frequency and it doesn't do the job, then I leave it. I'm assuming since eq isn't taking care of it, then those frequencies most likely are room modes. Is that a reasonable conclusion to arrive at without physically measuring the space? I don't have any issues with imaging or soundstage. I still get up to see if my center channel is on when listening to music! The Ultra towers are very good at both and I've played extensively with positioning them (moving them, and running a sweep after each move). I believe them to be optimized where they are.

I'm only interested in getting it to sound as good I can with the tools at hand. I don't want absorbing or diffusing panels, room treatments, or rearrange my living room and Alex knows that.

This is my in room response right now with no smoothing or room curve applied. It's also the graph to which TheWarrior was referring to when he said he could only assume my bass sounds bad, is full of bloat and I need to scrap the work I've done (with @ATLAudio's help) in these last 25 pages and start over.

I'm not seeing it? He keeps telling me that this in no way shows that I have a good bass response without measuring my asymmetrical room with vaulted ceilings and many uneven parallel surfaces to the nth degree. Am I doing something wrong? That's what I feel is being implied.

 

[William Lemmerhirt]

Yeah J. Applying boost/cuts without any appreciable movement indicates a room induced mode. If you’re manually EQing, as you noted, stop there. Boosting too high without movement of the curve doesn’t mean the subs aren’t working harder where you’ve boosted, only that you can’t hear it. That’s a good way to overdrive your subs. IMO, your response is beautiful. The next thing would be to evaluate waterfalls, or have someone evaluate your measurements with the mdat file. There they’d find things like impulse response and phase info. REW help files are great, as is the REW section at home theater shack.(avnirvana.com is the transcendent version).

 

[Pogre]

Yeah J. Applying boost/cuts without any appreciable movement indicates a room induced mode. If you’re manually EQing, as you noted, stop there. Boosting too high without movement of the curve doesn’t mean the subs aren’t working harder where you’ve boosted, only that you can’t hear it. That’s a good way to overdrive your subs. IMO, your response is beautiful. The next thing would be to evaluate waterfalls, or have someone evaluate your measurements with the mdat file. There they’d find things like impulse response and phase info. REW help files are great, as is the REW section at home theater shack.(avnirvana.com is the transcendent version).

This is the waterfall from the same measurement. Not sure what to make of it.

 

[William Lemmerhirt]

View attachment 22471
This is the waterfall from the same measurement. Not sure what to make of it.

I’m not schooled enough for waterfalls either. Looks like a lot of ringing, but that could be just the time scale. REW files talk about interpreting them but I can’t remember off hand how to scale them.

 

[Pogre]

I’m not schooled enough for waterfalls either. Looks like a lot of ringing, but that could be just the time scale. REW files talk about interpreting them but I can’t remember off hand how to scale them.

That's how I'm interpreting it too, but no real waterfall skills! I might try some more repositioning. I have an idea for moving the subs more nearfield. Maybe stack them in a corner. That'll let my towers breathe some more too.

 

[William Lemmerhirt]

That's how I'm interpreting it too, but no real waterfall skills! I might try some more repositioning. I have an idea for moving the subs more nearfield. Maybe stack them in a corner. That'll let my towers breathe some more too.

What kind of near field are you talkin? I don’t recall a lot of options. Besides, ya just can’t leave a good thing alone. Can ya?