Bass issues in my new writing room...

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Re: Bass issues in my new writing room...

Post by jaminem »

Wonks wrote: Thu Aug 18, 2022 2:25 pm Bass traps don’t have to go in corners, but they are far more effective there. You’d probably need almost twice the amount to get the same effect if they went against a wall.

He's already got them there...
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Re: Bass issues in my new writing room...

Post by noisyneil »

Firstly thankyou so much for the kind replies!

I think you're buggered....

I appreciate the honesty! 😂 You seem to have understood why this is causing me nothing but anxiety at the moment!

It also looks like the Kitchen ceiling is lower than the where you desk is, could you treat that bit?

Would this be smart?


I reckon headphones are the best choice.

Unfortunately, not really an option for cowrites.

could you hang a heavy curtain in front of the kitchen

I did think of doing that, but the HF reflections aren't bothersome in the least. It's still an option, but the bass issue is pretty fundamental (no pun intended) when trying to create a certain energy in a writing session.

scope for trapping in the corners next to the patio doors

Absolutely. This is where I would pop a couple of Tri-Traps. This room has to be ergonomically functional, first and foremost, so I'm slightly limited as to how much more treatment I can add and where it can go, but corner traps are fairly inobtrusive. Replacing the melamine in the existing panels with Rockwool might also be an improvement, as might freestanding boundary traps behind the speakers, although I'd prefer not to block the light.

He's already got them there...

Not yet, actually! All I have so far is those five Melatech panels.

I'm getting a headache... 🥴
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Re: Bass issues in my new writing room...

Post by Hugh Robjohns »

noisyneil wrote: Wed Aug 17, 2022 4:48 pmThe oddest of these is that, when they're on the desk shelf (sitting on IsoAcoustics stands), the bass drops off in a straight line from 100Hz. Pushing the desk right up to the window improves things slightly, and putting the speakers on stands is better still.

Just had a chance to take a proper look at your graphs.

The lack of LF with the speaker on the shelf is probably because the shelf moves in sympathy with the LF from the speaker. The bass restoration near the wall is the usual boundary effect, and the much better response on stands is because the speaker is being supported much more rigidly in space. These are all normal expectations.

I'm using IK Multimedia ARC to try to mitigate some of the dips and peaks, and the result is workable for the time-being...

I'd say those corrected responses are entirely acceptable. You're within +/-3dB all the way down to 20Hz. What more do you want?

... but to get any kind of solid centre image and bass response, I've had to pull my listening position quite far from the speakers, which leaves me feeling a bit disconnected.

The solidity of the centre image is generally determined by local reflections. In your case, it's probably diffraction from the screen edges and the desk itself — but you're obviously aware of that because of the cushion placement. I'd normally recommend bringing the speakers in closer but given your previous comments, that's not practical. So raising the speakers might help, if the stands allow, as might pushing the big screen further back behind the plane of the speakers. And more effective acoustic damping around the rear and tops of the desk will also help.

...But it's always going to be a compromise, and that's why decent headphones are such a help!
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Re: Bass issues in my new writing room...

Post by Hugh Robjohns »

noisyneil wrote: Thu Aug 18, 2022 2:47 pmWould this be smart?

It certainly wouldn't do any harm, and it could make a useful improvement without affecting normal daily living in any way.

...the bass issue is pretty fundamental (no pun intended) when trying to create a certain energy in a writing session.

I'm getting the impression that what you really want is not a flat bass response at all (since your ARC plot shows you're already getting that), but that you're really after a more visceral, trouser-flapping bass to give the impression of club-like 'energy'. Sadly, that's not gonna happen with KH120s. Not what they're designed to do.

The KH750 sub would give more LF energy that you can feel, obviously, but it will also lead to disturbed neighbours and, in all probability, a more lumpy bass response.

I'm getting a headache... 🥴

In a multi-functional space like yours, there must always be a significant level of compromise. You simply can't install the amount of acoustic treatment needed to achieve pro-studio standards of performance. I suspect you can make it a little better than it currently is with well designed and placed bass trapping, but you'll also need to accept the inherent limitations and find ways to work around them.
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Re: Bass issues in my new writing room...

Post by James Perrett »

Hugh Robjohns wrote: Thu Aug 18, 2022 2:48 pm
noisyneil wrote: Wed Aug 17, 2022 4:48 pm ... but to get any kind of solid centre image and bass response, I've had to pull my listening position quite far from the speakers, which leaves me feeling a bit disconnected.

The solidity of the centre image is generally determined by local reflections. In your case, it's probably diffraction from the screen edges and the desk itself — but you're obviously aware of that because of the cushion placement. I'd normally recommend bringing the speakers in closer but given your previous comments, that's not practical. So raising the speakers might help, if the stands allow, as might pushing the big screen further back behind the plane of the speakers. And more effective acoustic damping around the rear and tops of the desk will also help.

I use monitors in my home setup that are the same size as the OP's and, similarly, I've had problems with the bass disappearing at the listening position but being stronger further back. Quite by accident (I tried putting them on top of some bigger speakers one day) I found that raising them about 400mm above the desk really helped. I would guess that I am no longer hearing the desk reflections.

The bottom of the speakers are just below ear height while the fronts of the speakers are just in front of the screen. This results in a very convincing stereo image which would probably only be bettered if I used a pair of point source speakers.
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Re: Bass issues in my new writing room...

Post by noisyneil »

I'd say those corrected responses are entirely acceptable. You're within +/-3dB all the way down to 20Hz. What more do you want?

Fair point, but the issue is that in order to get the bass response to a level that's correctable (i.e. without the ports turning into leaf blowers), the speakers have to be quite far from the listening position. They're currently 1.6m from my head, which means they also have to be quite far apart, and the result is quite far-away feeling. It also means, as you rightly point out, that the screen is in front of the driver plane, so that's not ideal.

you're really after a more visceral, trouser-flapping bass

No, not at all. If you could hear it in here, you'd know what I mean. ARC says it's correcting, sure, but I suspect there are a few variables it doesn't account for and the result doesn't have much natural weight or punch. As soon as you stand up and move a couple of feet back, it's all there, of course, but then you're reheheeally far away.

not gonna happen with KH120s. Not what they're designed to do.

Hence my pondering a sub, but it seems that might create its own issues. I might try and borrow one and see what it does.

disturbed neighbours and, in all probability, a more lumpy bass response.

I'm lucky in that the neighbour thing isn't really a problem, but the lumps might be. The room doesn't adjoin any other properties apart from one above, and between me and them is about a foot of concrete. I don't tend to listen loud at all either.

there must always be a significant level of compromise... accept the inherent limitations and find ways to work around them.

100%. I'm trying to get to the best case scenario, but I'm under no illusions.

The bottom of the speakers are just below ear height while the fronts of the speakers are just in front of the screen.

Are you angling them down a bit so that the tweeters are pointing at your head? The bottom of my speakers are currently about 13cm above the desk shelf.
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Re: Bass issues in my new writing room...

Post by RichardT »

You can have a good room frequency response and yet the if the level of resonance at bass frequencies is too high you will hear mush. Without trapping in your space, you are not hearing the bass as it should be, even in the places where it has punch!

This is why room correction software is quite limited in what it can do - it doesn't actually deal with the biggest problem in domestic acoustics.

Trapping is explicitly designed to help with this. Broadband trapping, like the GIK acoustics traps, is the best thing to start with, possibly supplemented with tuned traps once the basics are in place. Broadband traps absorb frequencies down to 100Hz or so and if they are very thick lower than that. Tuned traps can operate at lower frequencies, but they only work for a range of about an octave around their centre frequency.

I definitely think you're not buggered in that space as long as you're willing and able to install the necessary treatment. If you need to maintain the light from the front windows, you could get some freestanding traps that you can move into position just when you're working at the desk.

My mixing space is essentially a long, narrow underground concrete tunnel which sounded dire, but now sounds pretty good. I've used a lot of trapping behind, beside and above the speakers, even between them, and supplemented that with some broadband trapping towards the rear and some tuned traps at 70Hz. So it can certainly be done.

Just to add - it can be ok for the end of the room away from the speakers to be more 'live' than the end with the speakers.
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Re: Bass issues in my new writing room...

Post by Martin Walker »

James Perrett wrote: Thu Aug 18, 2022 3:10 pm I use monitors in my home setup that are the same size as the OP's and, similarly, I've had problems with the bass disappearing at the listening position but being stronger further back. Quite by accident (I tried putting them on top of some bigger speakers one day) I found that raising them about 400mm above the desk really helped. I would guess that I am no longer hearing the desk reflections.

Raising the loudspeakers above the desk can certainly improve bass end, but not necessarily connected with the removal of desk reflections (although they may be improved too).

Given the typical dimensions of the home studio, it's fairly common for the loudspeakers to end up positioned halfway between floor and ceiling, where they would be sitting at the null point of the lowest vertical room mode.

Without lots more bass trapping to even out this mode, it might simply be that placing your loudspeakers into a different part of the vertical room mode enables them to flatten out that particular bass dip.
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Re: Bass issues in my new writing room...

Post by noisyneil »

Update:

Two pairs of GIK Tri-Traps and one Monster Bass Trap just arrived.

Traps in position.


Here are some new REW measurements.


TL;DR:

1.5m no traps vs traps


1.15m no traps vs traps


As you can see, the new traps make much more of a difference when the speakers are further away, but perhaps this means there's more of a problem for them to fix and I should have them closer to the listening position. Sorry if this is a silly way of thinking about it; I'm new to all this.

Would you say this is a marked improvement or is it a drop in the ocean when it comes to absorbing low end?

Thankyou once again for all your helpful comments. 🙏🏼
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Re: Bass issues in my new writing room...

Post by RichardT »

Personally speaking, I would judge the effectiveness of the trapping by ear, rather than by measurement - or at least I would treat what it sounds like as more important than how it measures.

How you hear the room is dependent on a complex mix of frequency responses, reflections, resonances, cancellations and non-linear hearing processes and in particular the frequency response graph isn’t a good indication of the quality of the sound you’re going to get.

Because of all that complexity, it’s very important to experiment with positioning of the traps.

Obviously the corner traps have to go in the corners - though you can tune the distance from the walls.

I would be tempted to bring the speakers in and put the monster trap at speaker level, between the speakers and the windows. That way it will help with first reflections from the windows and absorb a high proportion of back-facing sound energy. Of course, that may not be domestically acceptable!
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Re: Bass issues in my new writing room...

Post by Wonks »

Just linking to the pictures directly for you.

1.5m:
Image

1.15m
Image
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Re: Bass issues in my new writing room...

Post by noisyneil »

help with first reflections from the windows and absorb a high proportion of back-facing sound energy

Tricky to do the way you're describing, but what I could do is get a second Monster Trap and have one behind each speaker. They happen to fit neatly into the window frame. As I only have the one at the moment, here's the left speaker with the monster in both positions:

Image
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