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Rooms, Speakers, and EQ Curves

M

mercalia

pfm Member
"Paul Hales, founder of Pro Audio Technology, talks about room correction—or as he prefers to call it, room compensation. Topics include some of his fundamental principles of room EQ, sound directivity from various objects such as violins and speakers, how microphones do not capture sound in the same way that human ears do, how sound interacts with small to medium-sized rooms, target response curves (including the X-curve), how conforming to the X-curve causes the sound to be louder and more harsh than it should be, his suggested modification to the X-curve, answers to chat-room questions, and more."

interesting podcast - Pauls Hales take is that we live and move in rooms where we hear live music and sounds so rooms are not a hindrance to hifi ( get the earphones out? no ) but part of the experience as they would be in a live concert. He cites the example of how terrible a violin can sound close to without the support of the room where it is being played.


https://twit.tv/shows/home-theater-geeks/episodes/345?autostart=false

or down load video
http://twit.cachefly.net/video/htg/htg0345/htg0345_h264m_1280x720_1872.mp4
 
Thanks for posting, thought it was an informative vid. My target curve is very similar to the modified X and Harman target curves with a bass boost and de-attenuated flattish mid range. I find its very relaxing and enjoyable at low listening levels giving you head room when you want to whack the volume up.

Unfortunately I don't think many on here seem to use EQ. They prefer to use exotic power chords, speaker wire and interconnects to tune their systems. :)
 
Room correction EQ etc can have a massive affect on a systems SQ.
I link it very closely with acoustic treatment panels, bass traps etc.
Far more cost-effective than trying to get cables, stands & suports to "fine tune" a system.
The potential downside with room treatment, room EQ etc, is that it is FAR too easy to over-do it, resulting in a flat, dull, boring sound, even though these systems tell the user that its giving a neutral line.
Whilst Neutral can be seen as correct, it doesn't necessarily come over as sounding good.
 
DNM said:
Thanks for posting, thought it was an informative vid. My target curve is very similar to the modified X and Harman target curves with a bass boost and de-attenuated flattish mid range. I find its very relaxing and enjoyable at low listening levels giving you head room when you want to whack the volume up.

Unfortunately I don't think many on here seem to use EQ. They prefer to use exotic power chords, speaker wire and interconnects to tune their systems. :)
Click to expand...

Quite a few people I've interacted with do. And I do.

I guess if you have a streaming front end and some digital components, and have tried decent solutions like Dirac or Acourate, rather than basic PEQ (which I also use with care) then you'll embrace it once you hear the results.

I learnt the hard way that messing with subtle EQ by changing cables is an expensive fools game. I'm convinced the only difference between exotic cables is a very slightly different frequency response, which gives the effect of a noticeable change to 'detail' or whatever. You can do the same in an instant with EQ, and actually get the sound you want.

I really think modern 64 bit floating point math for audio processing is transparent, or certainly is relative to the gain you get. There are limits like everything, but it's amazing the difference.

Dirac was the most obvious upgrade I ever had.

But measuring etc isn't for everyone, especially if you have multiple sources and like swapping speakers around etc.
 
manicatel said:
Room correction EQ etc can have a massive affect on a systems SQ.
I link it very closely with acoustic treatment panels, bass traps etc.
Far more cost-effective than trying to get cables, stands & suports to "fine tune" a system.
The potential downside with room treatment, room EQ etc, is that it is FAR too easy to over-do it, resulting in a flat, dull, boring sound, even though these systems tell the user that its giving a neutral line.
Whilst Neutral can be seen as correct, it doesn't necessarily come over as sounding good.
Click to expand...

Yes, EQ can certainly go horribly wrong and should only be administered with due regard to the constraints of a system. I avoid boosting frequencies except the bass whereby using subs gives me a lot of headroom. Everything else is de-attenuated to achieve my desired response.

I agree, a flat curve is very dull and small changes can have a significant impact, both negative and positive. Its made a massive improvement to my system and I'd never be without it. Its a shame so many audiophiles can't get over the phobia of sticking an equaliser or DSP in the signal path as they'd be amazed by what their systems are capable of sounding like. For those with Roon, the new DSP feature is excellent and well worth experimenting with.
 
I tried to replicate my DIRAC correction using the roon parametric with quite impressive results .. wasnt as good as DIRAC but a damn sight better than nothing.
The DSP engine in roon is awesome
 
Hifi_swlon said:
Quite a few people I've interacted with do. And I do.
Click to expand...

I'm sure they do, I was just having a dig at the cable threads which seem to be far more prevalent on PFM.

I use Dirac too but like PEQ its a learning curve and very easy to get horribly wrong. Poorly positioned measurements and overdriving the speakers will yield terrible results. Get it right however and I think its possibly one of the biggest upgrades you can make, albeit confined to a listening area.
 
Rodney gold said:
I tried to replicate my DIRAC correction using the roon parametric with quite impressive results .. wasnt as good as DIRAC but a damn sight better than nothing.
The DSP engine in roon is awesome
Click to expand...

Yep, its very impressive, especially as its the first iteration with hopefully more to come.
 
MattSPL said:
Any frequency plots to share after EQ? I'm in the process of EQing my own setup.
Click to expand...

If I had any you'd be welcome but I deleted them when I left my MBP with the Apple store last month to have a new logic board fitted! Thought I'd backed everything up to an external drive then deleted All Files and Trash forgetting Dirac projects and REW measurements were stored in a VM Fusion Windows 10 session, which was deleted :mad: I haven't bothered redoing the Dirac measurements yet because I can still use the filters in my MiniDSP.

In any event, post Dirac measurements are difficult because you really need to take 9 measurements using REW from the exact same position you took the original Dirac measurements, to give you an accurate idea of the FR correction. I once took a few random REW measurements of Dirac on/off across the listening position and each measurement with Dirac enabled shifted FR closer to the target curve. Of course the SQ is totally dependant on the measurements you took and what you are asking Dirac to correct. As with any EQ, you also need to be sympathetic to your speakers limitations. A visually pleasing FR does not necessarily equate to good SQ.

Roon doesn't have a measurement function yet but I think its possible to record the REW test tone then play it through Roon, which should allow you to measure Roon's EQ. I haven't tried this yet but I'd be interested to see the results and happy to share.
 
DNM said:
If I had any you'd be welcome but I deleted them when I left my MBP with the Apple store last month to have a new logic board fitted! Thought I'd backed everything up to an external drive then deleted All Files and Trash forgetting Dirac projects and REW measurements were stored in a VM Fusion Windows 10 session, which was deleted :mad: I haven't bothered redoing the Dirac measurements yet because I can still use the filters in my MiniDSP.

In any event, post Dirac measurements are difficult because you really need to take 9 measurements using REW from the exact same position you took the original Dirac measurements, to give you an accurate idea of the FR correction. I once took a few random REW measurements of Dirac on/off across the listening position and each measurement with Dirac enabled shifted FR closer to the target curve. Of course the SQ is totally dependant on the measurements you took and what you are asking Dirac to correct. As with any EQ, you also need to be sympathetic to your speakers limitations. A visually pleasing FR does not necessarily equate to good SQ.

Roon doesn't have a measurement function yet but I think its possible to record the REW test tone then play it through Roon, which should allow you to measure Roon's EQ. I haven't tried this yet but I'd be interested to see the results and happy to share.
Click to expand...

Ok thanks, I'll try and post some plots later.
 
DNM said:
I'm sure they do, I was just having a dig at the cable threads which seem to be far more prevalent on PFM.

I use Dirac too but like PEQ its a learning curve and very easy to get horribly wrong. Poorly positioned measurements and overdriving the speakers will yield terrible results. Get it right however and I think its possibly one of the biggest upgrades you can make, albeit confined to a listening area.
Click to expand...

Same here,mine is set for a sofa,there is now a very defined hot spot in the middle of said sofa,have tried setting the mike further apart,but this didn't make much difference.

I did define my own curves and made maybe a dozen different files,but always resort back the the default optimised setting.

Several friends have/are now going down the same route and they like me are diehard vinyl users,I went for the minidspdirac 22a,improved my system by quite some margin now the bottom end is under control.
 
Thanks for the link.

I just wish the host would stop interrupting and that creepy laugh...

R
 
yes Father Christmas and his laugh - It used to freak me out but I must have got used to it. The podcast has a live element with irc and I suppose he has to keep them happy also. As mentioned they did a companion piece some time ago. I am glad some here have found the podcast interesting. Twit TV has a number of interesting podcasts ( why oh why call it Twit TV. maybe I dont get it but "Twit" in the UK is an insult? )
 
I just watched the podcast and what seemed like a useful idea was measuring near-field as well as listening position to see how the direct sound compares/ contrasts with the room sound.

And I know what he means when he says some cinemas are simply too loud when playing adverts, trailers and films. The modified X curve seems like the way to go to tame the overall sound.
 
mercalia said:
Twit TV has a number of interesting podcasts ( why oh why call it Twit TV. maybe I dont get it but "Twit" in the UK is an insult? )
Click to expand...

Sad geeky but true answer: the network of podcasts was started by Leo Laporte on the back of his "This Week in Tech" radio show / podcast.
 
So Paul Hales returns to give a second look at sound science where he openly admits that sound science is in its early stages and still is inhabited by myths

"With so much more to discuss than we could get to last week, host Scott Wilkinson continues his conversation with Paul Hales, founder of Pro Audio Technology. This week, he explains why he believes that audio science is relatively unrefined, leading to lots of dogma, misinformation, uncertainty, and inconsistency. Next, we dive into immersive-audio systems, including the importance of multiple subs, sophisticated bass management, and speaker directivity. Also, we talk about measuring sound pressure levels, answers to chatroom questions, and more."

download the podcast -
http://www.podtrac.com/pts/redirect...o/htg/htg0346/htg0346_h264m_1280x720_1872.mp4
 
Interesting thread and listen.

Here's a question: Do any readers here give much credibility to the Bang and Olufsen "sound lens" technology? I went to a demo once, and have read about it, and they maintain that the technology allows the lens on top of their high end speakers scans the room (with a radar like system) and calibrates the speaker accordingly. It, supposedly, takes in and accounts for room dimensions, furniture and so on.

I know their kit is more for aesthetics and not generally given much credibility with audiophiles - but it seems like an interesting approach to take rather than an external EQ.
 
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