How NOT to set up speakers and room treatment ( Goldensound)

[tmtomh]

putting foam on the walls will create an EQ that is biased toward high frequencies, damaging the response of an otherwise good speaker you may have bought.

Very dumb question here: why would foam absorbers create EQ biased towards high frequencies? Wouldn't foam absorb high frequencies since their wavelengths are so short, while allowing lower frequencies to pass through and reflect off the walls? In other words, if absorbers are generally ineffective for absorbing bass because the wavelengths are too long, then why would absorbers make a room sound more trebly?

Also, if one doesn't have coaxial speakers, wouldn't a couple of ceiling panels about halfway between the speakers and the listening position help even out the off-axis response?

 

[Galliardist]

Again - do whatever you want in a home environment. That's all taste. Studios can't have that.

That itself may not be completely true. Try recording a solo instrument, close miked, in a really dead room. It can be truly horrible.

 

[MacClintock]

Finally GoldenSound has the proper environment to listen to the sound differences in DACs...

 

[Mrpinortiner]

Interesting choice of toe in on the Focals. The soundstage must be very narrow.

 

[holdingpants01]

I skimped through the video and it's mostly very basic stuff for a home studio, not necessarily for recreational listening, however there's one potential big issue. He doesn't show decay time below 50Hz on the RT60 graph (just the waterfall but it cuts at 400ms or so), there's this weird suck out at 100Hz which suggest leaking outside through a wall or door but below that the decay time sharply rises. You can see on the waterfall that it doesn't even fit into the graph below 50Hz. What he did is he shortened everything but the bass by using broadband absorbers so issues with bass probably became even more apparent. I've been in rooms like this too many times and it's quite annoying to have two kinds of presentation at the same. Everything but the bass is tight, but there's like a reverb added to the low end. It's not good unless you address it, but it's way harder to do than whatever he did without changing the room construction. A pair of PSI Audio Avaa's would be a start, then more measurements and tackling the biggest offenders in the low end with tuned resonators one by one. BTW his frequency response graphs are too smoothed to be usable, there are probably big nulls at 200Hz and ~280Hz. Overall at some point going with 8351+W371A or 8381 just makes more sense if flat frequency response and less of room sound is desired from free standing speakers

 

[amirm]

Speaking from experience here: EQ can't do crap about nulls. Putting more energy into a null just makes it deeper.

Not my experience. As I explained, the dips are partial cancellation which means you can fill them in.

A technique used by auto-EQ systems is to bring all the levels down to close to the dip. And then boost the dip a bit. Once there, you have the flatness you need. You can then increase the gain to get back to where you want to be. To be sure, you will be wasting amplifier and speaker power but you will be doing the same with those absorbers.

 

[amirm]

Further, EQ can help reduce the level of a modal peak, but cannot do anything about its ringing.

Of course it can. The math forces it to be the case. Again, covered in Dr. Toole's book:

You can hear the effect so well. Bass becomes tight without hanging in the air as would be the case without EQ. The peaks are minimum phase so the outcome is preordained.

A cool bonus is that by taking advantage of the free amplification you get out of these peaks, you lower the distortion in the speaker and amplifier by using negative gain in the filter. The result is much cleaner sound. An absorber is doing this after the fact so can't do this.

 

[Axo1989]

there's this weird suck out at 100Hz which suggest leaking outside through a wall or door but below that the decay time sharply rises

The general rise in the lower octaves is normal (and the EBU standard accommodates that) but the 100 Hz suckout struck me as weird also, wonder why he didn't address it. Just looking at it would drive me nuts, never mind how it sounds.

 

[amirm]

Very dumb question here: why would foam absorbers create EQ biased towards high frequencies? Wouldn't foam absorb high frequencies since their wavelengths are so short, while allowing lower frequencies to pass through and reflect off the walls? In other words, if absorbers are generally ineffective for absorbing bass because the wavelengths are too long, then why would absorbers make a room sound more trebly?

You read what I wrote wrong. I said the same thing. Than a thin absorber only acts on reflected high frequencies. So it has an effect of just EQing the signal and taking out some of the highs. So in that sense the filtering it does is leaning toward high frequencies. Not that the effect is that.

 

[holdingpants01]

The general rise in the lower octaves is normal (and the EBU standard accommodates that) but the 100 Hz suckout struck me as weird also, wonder why he didn't address it. Just looking at it would drive me nuts, never mind how it sounds.

View attachment 288931

I am aware of that, but as you can see he changed the RT60 response above the 100Hz to the lower end of this scale while leaving the bass at the high end of the scale. Like I said, this disconnect between those two is problematic as it makes it very obvious by contrast

 

[abdo123]

I personally follow Dr Floyd Toole and Sean Olive who have decades of research and experience.
credentials.

not someone who Willy nilly made his first room and is peddling nonesense.

The recommendation for RT60 values is between 200 and 400 ms for a reference mixing room.

So far you have provided no evidence on why what they’re doing is wrong.

 

[amirm]

The recommendation for RT60 values is between 200 and 400 ms for a reference mixing room.

So far you have provided no evidence on why what they’re doing is wrong.

I provided a fairly long list. What difference does it make if he said it vs I?

 

[holdingpants01]

The recommendation for RT60 values is between 200 and 400 ms for a reference mixing room.

So far you have provided no evidence on why what they’re doing is wrong.

but the room they show is not a mixing room, even if they used some guidelines for one, while failing to address low end decay doing it. They've built a bad mixing room and weird dead recreational listening room at the same time, with possible huge issues with asymmetry - there's a door in a corner behind one speaker and windows on one side. Notice the first thing in the video is a guy saying the "sound is touching his ears", I know this sensation and it's usually caused by whacked phase in bass between the spots where ears are. BTW the door was open during this shot

 

[Axo1989]

I am aware of that, but as you can see he changed the RT60 response above the 100Hz to the lower end of this scale while leaving the bass at the high end of the scale. Like I said, this disconnect between those two is problematic as it makes it very obvious by contrast

As others have observed, controlling deep bass reverb requires very thick velocity absorption (alternately membranes, Helmholtz resonators or similar). He hasn't done that really (although the corner bass traps look like ≥ 600 mm square).

But I think the 'disconnect' is a visual artefact of the (only relatively) low 100 Hz number. In fact (contrary to what you've written there) his < 100 Hz bass RT looks generally a just bit lower than the > 100 Hz region (in the final graph in that series). But the FR graph shows roll-off from around 40 Hz, which is biasing the result. And conversely minimising any issue with uncontrolled sub-bass reverberation.

Spoiler: I'm looking at the graphs at 14:00.

Looking at it another way, his final RT at 100 Hz is ~200 ms. My room is below that entirely for 100 Hz and above, so I'd say that's the only frequency he's adequately treated.

If you prefer listening to a more reverberant room that's totally fine of course, it likely reflects your musical preferences.

 

[holdingpants01]

there's not much going on below 50Hz in the response anyway, are those Focals that bass shy?

 

[holdingpants01]

As others have observed, controlling deep bass reverb requires very thick velocity absorption (alternately membranes, Helmholtz resonators or similar). He hasn't done that really (although the corner bass traps look like ≥ 600 mm square).

But I think the 'disconnect' is a visual artefact of the (only relatively) low 100 Hz number. In fact (contrary to what you've written there) his < 100 Hz bass RT looks generally a just bit lower than the > 100 Hz region (in the final graph in that series). But the FR graph shows roll-off from around 40 Hz, which is biasing the result. And conversely minimising any issue with uncontrolled sub-bass reverberation.

Spoiler: I'm looking at the graphs at 14:00.

View attachment 288937

Looking at it another way, his final RT at 100 Hz is ~200 ms. My room is below that entirely for 100 Hz and above, so I'd say that's the only frequency he's adequately treated.

If you prefer listening to a more reverberant room that's totally fine of course, it likely reflects your musical preferences.

this is not final measurement, this one is, 50Hz is approaching 500ms so for 40Hz it will be way more than that

 

[Axo1989]

there's not much going on below 50Hz in the response anyway, are those Focals that bass shy?

Good question: no in-room from this Stereophile review but you can see something of the same rolloff:

this is not final measurement, this one is, 50Hz is approaching 500ms so for 40Hz it will be way more than that

Got it, I missed the post-DSP one.

That makes sense, with some actual output at that frequency we can better see the room behaviour: 500 ms is within the acceptable range, although I'd prefer the overall was smoother. He may have to do more work if he significantly increases sub-bass extension, etc.

 

[tuga]

There is no such thing as "perfect room." People chasing that are making another mistake. The room simply needs to be good enough to sound excellent and give you all the comforts you need. Here is Dr. Toole's room:

His large space automatically has an advantage over GS room. My room is far bigger still which much reduces impact of room modes.

As I said, people have been taught to count acoustic absorbers in a room as a measure of excellence. That is completely wrong. They are copying stuff without knowing and understanding the underlying science. I know a number of people who filled their rooms this way, only to take them all out one day and realizing how much better the sound was!

Does Toole have a preference for reflected sound?
That room looks terrible, no symmetry and the listening chairs look far too close to the rear wall.
I can't see how that can be considered a good example...

 

[abdo123]

Does Toole have a preference for reflected sound?
That room looks terrible, no symmetry and the listening chairs look far too close to the rear wall.
I can't see how that can be considered a good example...

You seem to be missing the point.

 

[Nkam]

Ok.



His final graph shows reflection times mostly in the 300-400 ms range, that's in the usual EBU/ITC range for a listening room.



Yeah same. It was reasonably comprehensive and methodical.



For sure, he specifically mentions that preferences there may vary with musical taste: classical/jazz listeners often going for longer times. I like electronic and prefer shorter.



Not surprising.

Edit: fixed acronym dyslexia

Amrir makes some salient counterpoints but I think misses an important factor, touting DSP vs treatment. Cameron starts with what I assume is a concrete apartment (or masonry house, not specified, but very reverberant) and reflection times around a second. Wild. And not uncommon. DSP simply won't resolve this.

My room is naturally dry (no added treatment but some traditional Japanese timber construction means the floor and ceiling are giant absorbers and the side walls can be open or closed) so I can go pretty much straight to DSP. But that's not so common.

Spoiler: and I do like it dry.

View attachment 288909

Then when setting up, REW has an improved reverb time method for smaller rooms now, which I haven't compared yet.

That would makes sense, and lead to better discussion.

he changed the RT60 decay time because I told him personally that 250ms was way to low.

as humans we have evolved to take cues from reflections.
he thinks that all those reflections in the impulse measurement Should be deleted. Good luck with that.
Dr Toole specifically brings this up in his book.


to all this is what I read and I actually paid a professional from Audioholics to teach me to measure and treat my rooms.

people who do this for a living.

all you need to know is in this book and more.
from a guy who paid his dues and did a ton of research.
yes , that’s what annoys me the most.
that someone is 24 , has ZERO credentials in audio, makes his FIRST room and makes a video of it.
but I don’t care what other ‘ kids’ think.
do whatever you want to your rooms.

The guy below did a sh$t ton of research. And if you read the book and experiment with some of what he has tested. Yeah it will sound good.

or go ahead and listen to ‘ someone’ on the internet with zero credentials. Up to you.