Or, as a quick’n easy alternative there is HouseCurve (for Apple users) that helps creating filters that compensate for your room. There is a section here in the forum and the developer Greg is giving great support.
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No, one must not correct the bass in any case. Please inform yourself about room treatment with active bass absorbers and about speakers with cardiod bass radiation. And there are room shapes which are very room mode friendly. No filter can handle the reveberation by the way.
There are (like always in sound reproduction) disadvantages by using IIR oder FIR, also by using under the Schroeder frequency. I am thinking about short bass impulses in music.
But I must admit that in most cases the benefits of proper filtering up to the Schroeder frequency are much higher than the concerns. So yes, using REW is a must.
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Oh, I am very informed about that. Active bass absorbers are very expensive. The PSI C214 for example costs nearly $4,000. They do work as the CEO demoed it for me at AES conference last year but you may need multiple to fully correct the response. Roon EQ on the other hand is free.
As to cardioid bass, your choices of speakers will then be highly limited. And even then you better measure and correct with EQ.
You are stating typical comments by people who sell acoustic products with nary a proof point of these audible problems. The comment is also wrong as a matter of mathematics. Most of the peaks in response in low frequency range are minimum phase so correction in frequency will automatically mean correction in time domain. Bass impulses most definitely tighten up and you easily notice the overhang reduced or gone.This is all supported by research into preference for EQ. See AES paper:
The Subjective and Objective Evaluation of Room Correction Products
Sean E. Olive, John Jackson, Allan Devantier, David Hunt and Sean M. Hess
From paper conclusions:
“Room correction, when done properly, can
provide significant improvements in the sound
quality of loudspeakers in rooms. T**hree of the **
**five room corrections produced significantly **
higher preference ratings than the uncorrected
loudspeaker/subwoofer”
And
"Listener comments and spectral balance ratings
indicate the more preferred room corrections
sound more neutral, less colored, with more
ideal spectral balances. "
Again, all of this can be done for free with speakers you already have.
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If you do have long resonanes despite correcting bass peaks with Roon DSP there are other software alternatives (VST plugin or standalone).
Room shaper was measured by @Mitch_Barnett. Dirac ART is more expensive, and not available yet on desktop version but bass control is.
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I think because long resonances or decay time is a function of the room and not of the speaker, so you need more than software and more then a PEQ. You need an actor and a reactor like the traps from PSI Audio (I use it successfully) or something like DIRAC ART. A DBA is a good solution too if the room is nearly quadratic. As an alternative or additionaly one can use very thick and large material like Sonorock for room treatment.
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Right, this is exactly what Thierry’s Room Shaper DSP product does as measured in this review:
Due to long wavelengths below 100 Hz, passive or active room absorbers do very little to dampen bass decay/overhang in the room, unless you stuff the room with these products. Aside from the expense, stuffing the room will also suck the life out of the music. Source: ex manufacturer of passive acoustic treatment products including bass traps.
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Its also so much cheaper than Dirac ART, particularly when you have Roon “front end” with all its DSP functionality.
Have you looked at xtalk shaper?
Lots of buzz around UBACCH and crosstalk cancelation in general.
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When these are the room modes corresponding with the dimensions of the “captured air in the box” (=your room), you can see this as the end part of the sound system like being connected to your woofer-cone (Amir talks about a minimum phase part). This captured air, sort of, loads the speaker cone at its resonant frequencies (the room modes) so the whole thing can be equalized, controlled, even with an analog parametric equalizer.
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That sounds like the frequency-depending directivity pattern of the speaker and the room´s RT60 at different frequencies are not really a perfect match. That is a common thing if you have a constantly increasing directivity index of the speaker (very typical in narrow speakers with rather small coaxial midrange drivers) and a constantly decreasing RT60 towards higher frequencies. The result is in many cases dull tonality of the perceived reverb, subjectively lame impulse response and the sound lacking both crisp treble details and ´air´.
As you can solely EQ the on-axis response, adding treble can help the aforementioned problem only to a very limited degree as you end up with treble-laden direct sound while the indirect sound still lacking treble. It is not particularly balanced although it might sound less dull.
If your room has such ´warm´, ´dull´ reverb characteristics resulting in a constantly decreasing RT60 towards higher frequencies, it is highly recommended to find a speaker which offers a higher directivity index in the midrange, especially from 500 to 1500Hz, not narrowing its beam towards higher frequencies (as the majority of slim speakers with smaller midrange drivers does even if they are named ´constant directivity´). Unfortunately, such thing is rare among slim high end speakers or compact studio monitors.
Despite the aforementioned ratio of direct and indirect sound not being constant through the mid/high range, bass modes resulting in audible booming are the second thing you cannot EQ. Yes, you can reduce level in this narrow band thereby making booming it less annoying. But this will neither be satisfactory at all SPLs nor will it result in a balanced bass response and subjectively tight impulse reproduction.
That’s not a good advice in my understanding as avoiding booming and audible resonances should be the first step to achieve better bass reproduction. EQing might be helpful as a second step but it would not fix the aforementioned problems if they are drastic. In many cases, repositioning of the speakers, passive room tuning or even exchanging the speakers to models with a better-fitting directivity index are necessary steps before thinking about EQing.
Enno mentioned cardiod directivity index in the bass region. That is in many cases the best solution if this really works down to 30Hz. Which is AFAIK only available in pretty expensive and pretty chunky speakers.
Avoiding modes and booming by taking use of the speakers high directivity index in the bass region is not the same as EQing. Even if you end up with a similar in-room frequency response. Avoiding resonances if always far superior to flattening the frequency curve but forgetting about time domain and different behavior with different impulses.
If you need only 2 of these, it is still cheaper than doing it passively or opting for fullrange-cardiod speakers. An EQ might be for free and it might help reducing the level of annoyance booming could cause, but it is not the same thing when it comes to bass reproduction. Far from that.
That is rarely the case with room modes or other resonances resulting in booming. As the word ´resonance´ is suggesting, you have something resonating and it can do so for a pretty extended period of time. You can correct the frequency curve to optical perfection but in most cases it would not be audibly the same for all SPLs or impulses in the source material and you can still measure and hear the resonance.
Enno´s experience with this matter is 100% correct according to my experience.
There are some absorbers being pretty effective in the region below 100Hz, but these are either active ones like the aforementioned PSI Audio, or they rely on a principle working in the bass region, like a panel absorber or narrow-bandpass bass trap. But yes, you need several of them and you need to know where to position them.
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Wow, is this a mega thread! Definitely some raw feelings on both sides of this one!
As I sit here listening to classic rock through my Liberty DAC II (in lieu of my Schiit Gumby - 2 DACs I suppose Amir would not consider to make the grade), my thoughts:
To me, neither Amir nor Mike come off very well in this thread. Mike seems very defensive and desperate to justify releasing a product that doesn’t measure well due (apparently) to mains leakage, and has attacked other products. Amir appears closed minded and not to consider any other factors than his measurements in judging audio gear. Even if his substantive position makes 100% sense to me, I take issue with anyone who acts sure he has nothing more to learn in life. It is also clear he does not always feel the need to address others with diplomacy. This is intended as an observation and not my own ad hominem. It’s to explain why there is sometimes a strong reaction to an insulting tone.
As to measurements, my opinion is that, if done correctly, they are a useful tool in judging likely performance at home. But there ARE other tangible factors that are not subjective, such as synergy with other components. For example my Avid Pulsus phono preamp’s signal is just too hot for my Levinson preamp – sounds shrill – but my Balanced Audio Tech preamp handles that signal just fine.
Piling on doesn’t make a right here. It’s notable that there are 10-12 folks who “like” every Amir post and just 1-2 who “like” Mike’s posts. All that shows is the prevalence of a certain culture here at the Roon forum.
I tend to agree more with the objectivists and I certainly believe that audio tweaks that provide no measurable difference have little to no value other than as system bling, but I still find Amir’s manner to be off-putting and while he may be a trained listener to tones, I don’t think that applies equally to people. As above, not intended as an attack, but my own neutral (as opposed to objective) gauge as to why his tone creates controversy regardless of substance.
My main data point here is not about measurements, it is that Amir seems unwilling to consider that his polling mechanism at his website can sometimes function as an echo-chamber posse that is truly unfair to certain products or sellers, and he has been dismissive of well reasoned objections to the method of polling. My take: ASR polls should be broken into columns such as (1) I own this product; (2) I have heard this product, or (3) my vote is based on what I’ve read. Amir comes off as thinking that ASR is 100% perfect as-is. See above about my thoughts on people that feel they have nothing left to learn.
Secondarily, Amir seems to deny that he makes judgments and editorializes while discussing measurements. It’s one thing to say “this appears sub-par to class” (i.e. other products in same price range test better) but another to say “who could want this in their system” which is definitely the feeling I get when reading his analysis. It is not just informative, it IS judgmental.
Those supporting Mytek or just generally taking more of an “I trust my ears” approach seem to feel that purely using measurements takes the romance out of the hobby. That may be true, but in the end, we are talking about electronics and physics. So many audio hobbyists look for upgrades simply because they’re bored and they affirmatively thirst to buy that next expensive piece of bling because it looks cool and expresses status, when an actual sound upgrade clearly needs to include some level of scientific discipline.
But it also has to be to taste. That is why I feel both sides are simply talking past each other. At least, mostly in civil discourse (except as observed above), which I applaud!
I am a frequent poster against network tweaks. It’s not because I want to debate with everyone who posts that their audiophile switch has lifted a veil off. It’s because I don’t want newbies to feel they have to have these things to get in the game. For the service that ASR provides in that way, I thank Amir and agree with him. But telling someone their speaker choice is ugly, Amir doesn’t seem to know when he’s just subjectively opining himself, nor does it make him more right substantively.
In the end, I believe that if you like how something sounds, there is no reason to feel attacked because someone else doesn’t, or because it doesn’t measure well. HOWEVER, I would also call ■■ on posters that present as FACT that a product has a certain impact solely because of sighted listening, especially if it’s against established science. I’m OK if it’s presented as opinion or experience, not fact.
In the end, I would like to hear why Mike feels those main spikes are beneficial to his product and I would ask Amir to be a little more open to constructive feedback about ASR and his role in the posse attacks that can happen there.
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You know, they’re “likes”, not votes. There’s no “piling on”. Amir seems, to me, to be saying sensible things based on reality. Mr. Jurawicz’s posts seem, to me, somewhat confused. In fact, they seem to reflect an aspect of the “circle of confusion” Floyd Toole refers to in several of his papers and presentations. So I’m not surprised one is more “liked” than the other.
You’re free to build your own site and run it the way you want, aren’t you? If you’re proposing a change to ASR, why not do it there, instead of here? I didn’t even realize ASR had a poll system, I have to confess. But I also think there’s no way to make polls “scientific”, so why bother about specifics?
Even if I felt that this was accurate (I don’t), we have to remember that different people have different skills. Sometimes dispensing with verbal camouflage is an advantage. But a lifetime in the engineering and research world tells me that the diplomats are the ones who become lawyers, not engineers. Engineers like data, and they like it directly. Diplomats like escape hatches.
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Mind if I “pile on” your post?
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Can I ask Amir if you have ever heard a difference you couldn’t account for by some measurement?
And of course if so what?
.sjb
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It’s a good point and I didn’t mean to scold those that “liked” Amir’s posts. A lot of the substance of what he says I agree with, or at least find it thought provoking. I just anecdotally noticed (no, didn’t measure) that his posts seemed to have a constant 10-12m “likes” and envisioned people just going down the thread and liking each of Amir’s posts. I suppose I just jumped to that conclusion.
I actually had a plan to do that at one point albeit more about reviews of vinyl releases rather than equipment. But great idea - everyone send me your gear! I promise to return! 
Certainly. My point is that Amir hasn’t just debated Mike here, he has also debated other posters. Relative to “mortal” posters, he comes from an inherent position of authority due to his role at ASR. Thus, I suggest, shouldn’t need to resort to the amount of snark or condescension that I felt was leaking out. In effect he is at the podium and doesn’t need to sink to the level of the audience or below it.
That is not to disrespect Amir’s contributions and as I said I tend to lean in the direction of his belief system relative to audio, albeit not entirely since I probably have a lot of gear that doesn’t measure well but I love nonetheless.
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I see it a bit different, Amir and his adorers put teachers like Toole on a (deserved, I also like his work) podium.
I always thought that big scientists realized how little they know and engineers think they know all there is to know. This thread confirms this.
But nonetheless ASR can be a nice site for finding measurements and techtalk aside from the product-bullying.
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Well, no name calling here at all. Apparently if one appreciates ASR we are labelled ‘adorers’. Silliness now reigns this thread.
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Well this does not work in the direction you probably like it would. Yes, it shows how humble and always challengeable the science approach is, but it does by no means credit the believers in alchemy per se.
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It’s good when science is thought-provoking.
I don’t think anyone is at any podium, but whatever he does, I’m glad he does, otherwise he would probably not bother explaining in such detail what he’s talking about.
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Thank you for this very sensible post. I guess you won’t be surprised by the reaction of the ASR followers, although such unpolite posts are doing nothing but stressing your point. It is indeed a pity that everyone who finds ASR an useful and worthwhile audio site, and recognises Amir’s knowledge of audio matters, but thinks ASR is sadly run in a toxic manner, is treated as a fool (“silly is the most recent adjective”) as a believer in Alchemy. I’ve been a scientist for 30 years but in audio matters I’m just someone who’s been listening to a lot of live and recorded music for almost 50 years and has owned no more than a handful of audio gear. So, I suppose I’m the lay man, the average joe, in short, someone who should not question ASR’s authority and opinions. Well, my problem is that I have to live and listen to music with my own hears. The two main pieces of audio in my system (a streaming amp and a pair of standmount speakers) are, at least for now, very pleasing to my ears. I like it as close as possible to the sound of acoustic instruments in a live setting. Vocals, violins, the piano, guitars, should sound natural, with a decent sound stage. Well, one of these components was ranked as one of the best loudspeakers for the price by ASR, whereas the amp was trashed (pure junk they say). So, I really have a problem: my ears cannot relate to these measurements. Obviously, I should not trust my ears, that’s the mantra. Well, given the pleasure I experience when using my current gear, I’m kepping the amp and be happy (I’m not a reviewer, so I’m not telling anyone to buy the same gear). That’s fine. What is not so fine, is reading hundreds (maybe thousands) of angry and enraged messages of ASR followers insulting the audio company, trashing the amp with really obnoxious words, without hearing it. It’s like the inquisition. That’s what I call toxic. It’s a shame because there’s many good things about ASR. Tolerance is not one of them.
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It still seems to me that with listening preferences being variable there are assumptions that on average people prefer a flat response. When I’ve rented a car it’s interesting to notice the difference in my modification of eq compared to what was there. Over time i trend not to eq as i recognize how i can get used to any sound. This is what is fun about headphones, iems and earbuds with all of which you can find exceptional sound but quite a different range. This is what’s fun about switching in and out of my chain a tube preamp with the speakers. This is what’s fun about going to different musical performances in different venues. It’s all different, but what is the best or better? And for me? The fact that there are not ongoing abcd type tests on ASR like Toole described that compare different components in different combinations is a missing piece. Wouldn’t you need a statistically significant sample size to prove that the best measured for dsp and eq-ing result in the best sound on average for people’s preferences? The science that’s been shared so far i believe has resulted in the harman curve. But i haven’t seen anything besides that that attempts to get statistically significant and it’s not flat! I also believe hundreds were tested, so is the enough to know? And what about culture? Do people’s preferences change based on culture, life experiences including listening variety and learning?
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