Thanks everyone for the tips. I phoned both and then followed that with an email enquiry. Will report back on how it goes etc.

Cheers

17 hours ago, pistachio said:

Thanks everyone for the tips. I phoned both and then followed that with an email enquiry. Will report back on how it goes etc.

Cheers

I should mention that it was only the 50mm thick material that was readily available, the 100mm would have been a special order.

Cheers,

 

Thanks Rustee, yep, 50mm is all that I am after too.

 

Turns out that both contacts were able to supply the Martini Absorb. ACT Foam was going to be Absorb as a roll rather than panel form.

I've gone with CSR direct, which will be one pack of panels. If I'm lucky it may arrive before the week is out and give me the weekend to begin tinkering with thickness and placement etc.

 

So will continue to report on how that plays out.

Cheers all for your input.

Pete.

Bit of an update. So i have been experimenting with panels and measurements over the last few weeks when the household is empty - otherwise I get too many 'rolls of the eyes'!

During all these tests, I would still say my system was on the bright side but there is a definite improvement and I still have the curtain along the window to put in which I think will also assist.

It has been difficult for me at times to measure and hear the effect of a single treatment change here or there, but the accumulative effect of all the treatments in the room was more obvious. 

 

So today I decided to remove all the panels and run a measurement (no treatment aside from the rug) and then run a measurement with everything in place including some removable panels on the front wall and over the TV to measure the accumulative effect of all the panels. I decided not to try bass traps as my focus was taming the top end.

 

You will see below, the effects are in the right direction but maybe not as significant as I was hoping for. Would love to get your thoughts on the results.

 

Please note these are with the rug in place which, in itself, made an improvement. I will see if I can dig out a test before the rug and compare to one of the below, even though I normally try and only do comparisons on tests done on the same day. But it might be interesting to see if the overall improvement is more than what is shown below.

 

Waterfall:

First graph is without panels in place.

Second graph is with all panels in place. Decay times appear to have reduced a little and seem more uniform.

 

 

RT60

Overlay of tests with and without panels again. 

Red line without panels in place, blue line with panels in place. Reduction in reverb from 450hz and up.

 

Now this was an interesting one. I have always run my speakers with no toe thinking it would be less bright. Today I ran a measurement with the speakers toed in and to my surprise the top end dropped a bit - how?

It's not a big drop but any drop is welcome. Yellow line is toed in.

 

A pic of the front (unfinished) panels FYI. There is already a photo of the rear panels further up in the thread.

 

Any feedback or advice is more than welcome.

Cheers,

Russ

Edited September 14, 20223 yr by Rustee

Some of the thoughts in my head at the moment are:

- The most noticeable improvement was when I installed the rug and new rack

- Have I used the right materials for the absorption panels (Martini Absorb HD50). Should I have used the denser material, I feel the dooner had more of an effect.

- Have I used the right material to cover the absorption panels (polyester cotton)

- Are the panels worth it in my room considering the very little improvement due to the restriction on the amount of panels/treatment I can put in place

- Am I barking up the wrong tree. (should I be looking at EQ, different cart/stylus, speakers, diffusion etc..)

- Do I listen to music too loudly 

- Am I over-listening and not giving it enough time

- Am I heading in the right direction and just need to keep chipping away

 

Russ

Edited September 15, 20223 yr by Rustee

This was interesting to read, particularly:

 

"Density of a material is considered to be one of the important factors which governs the sound absorption of any material. There is increase in sound absorption value in the middle and higher frequency as the density of the sample increased [19] . The number of fibers increases per unit area when the apparent density is large. Energy loss increases as the surface friction increases, thus the sound absorption coefficient increases. Less dense and more open structure absorbs sound of low frequencies (500 Hz). Denser structure performs better for frequencies above than 2000 Hz. Various studies that dealt with sound absorption in porous materials have concluded that low frequency sound absorption has direct relationship with thickness. Ibrahim et al., [20] showed the increase of sound absorption only at low frequencies, as the material gets thicker. However, at higher frequencies thickness has insignificant effect on sound absorption."

 

So my choice in the HD50 when targeting high frequencies (based on the Porous Absorber calculator - or at least my interpretation of the graph) may not have been ideal. This is good news for me, there is hope yet.

 

Will enquire about some XXHD50.

Ok so XXHD50 is out of the question for my budget at least! It was 4 times the price of the HD50.

Will look at other higher density options that I might be able to experiment with.

 

 

 

 

 

Thick curtain is in which will hopefully help first reflections on one side at least.

No listening or tests done yet.

 

Edited September 22, 20223 yr by Rustee

Ok I thought I'd close out this thread with where I got to for now.

 

I'm pretty happy with the decay and reverberation times in my lounge room considering the limitations that come with a shared room.

 

Here's an overlay of the RT60 comparing result of my current everyday listening arrangement to one of the early tests I did before the rug, panels etc...

A mostly consistent reduction from 300Hz al the way up about 6.5khz, with a peak in reverb still occurring at 1k.

 

Now when the fam aren't home and it's serious business, I put the panels in front of the TV, behind the speakers and even throw a rug over my leather lounges.

A little better than the above results right through and the peak at 1k has now dropped from around 550ms to about 475ms. 

 

Waterfall graph looks good too with a reduction in decay across most of the range. Below only shows from 2k to 7k but you can see a definite and consistent reduction.

 

 

 

So overall I am happy, but more importantly I have learnt a lot - from taking measurements with consistency, to becoming a textile expert and making some panels, to learning how different things affect sound.. Has it solved my initial harshness at high volumes? - yes and no. I still have some brightness but it no longer sounds harsh and the room has a warmer more pleasant acoustic signature to it.

I have also recently got myself a reasonable streamer (my son put together a RP4 - thanks son!) so now with another reasonable quality source to compare to, I can confirm my vinyl playback is what sounds a little bright on some albums (particularly those with lots of electric guitar or busy musical passages ). 

So now I'm about to experiment with different loadings on my 2M Black and see what thats brings to the table.

One day I'd like to experiment with some different density treatment or even diffusion, we'll see. It's difficult to do these things in a shared room. Maybe one day I will have a dedicated play room.

 

A big thank you to everyone who chipped with help and advice. it really is much appreciated. I went into this to equally, improve sound and to tinker and learn. I have achieved both and had some fun along the way. 

 

Cheers all!

Russ

 

 

 

Edited October 28, 20223 yr by Rustee

nice work!

If you have EQ capability I'd try to reduce the long decay times around 40-70Hz.

 

Reducing reverb further above 1K is easy - only thin absorption is needed.

 

Mike

14 minutes ago, almikel said:

nice work!

If you have EQ capability I'd try to reduce the long decay times around 40-70Hz.

 

How, Mike, does one use EQ (say, using a miniDSP), to reduce the "long decay times from 40-70Hz in this graph"? (green graph):

 

 

 

Andy

 

On 29/10/2022 at 4:37 PM, almikel said:

If you have EQ capability I'd try to reduce the long decay times around 40-70Hz.

Thanks Mike - haven't introduced EQ at this stage.

 

On 29/10/2022 at 4:37 PM, almikel said:

Reducing reverb further above 1K is easy - only thin absorption is needed

And denser?

I never ended up getting my hands on any denser absorption than the HD50, so never got to experiment. 

 

If only I had a dedicated room, I'd be able to experiment and play so much more.

Kids just won't leave! 

Don't tell my wife or kids I said that!

58 minutes ago, Rustee said:

haven't introduced EQ at this stage.

 

Please can you help me understand why its better to do the room treatment and not EQ?

 

I dont know much about the field but would have assumed EQ would be easier to do and the priority?

57 minutes ago, Nada said:

 

Please can you help me understand why its better to do the room treatment and not EQ?

 

I dont know much about the field but would have assumed EQ would be easier to do and the priority?

 

Hi @Nada I guess everyone will have a different approach and different reasons for it. My understanding is that excessive EQ can actually negatively affect your sound. So the idea is to get your room and system sounding good as you can, then fine tune with some EQ.

 

For me, I like a minimalist system and don't know at this stage if or when I will try EQ. I know what I'm like, I can just see myself tweaking EQ to suit every song or album which i don't want to do. I have no tone controls on my vintage amps - it is what it is and I actually like it that way, I put on a record and enjoy it.

 

I want to get it sounding as good as practical and enjoy it, with the family - which I am doing.

 

 

Cheers,

Russ

1 hour ago, Rustee said:

So the idea is to get your room and system sounding good as you can, then fine tune with some EQ.

 

Thats does make sense.

 

I was just thinking of coming from the source ie the speaker first and the room second. If the speaker has a hot tweeter from a XO that has say +6dB in the mids  it seems like the first thing to do is fix the source. Trying to fix a problem like that with room treatments seems like hard work and the direct sound will still be hot.

 

I dont remember you saying what your speakers are. Do they have  a tweeter XO around 3kHz by any chance with a rising response?

 

On 29/10/2022 at 3:56 PM, andyr said:

 

How, Mike, does one use EQ (say, using a miniDSP), to reduce the "long decay times from 40-70Hz in this graph"? (green graph):

 

 

 

Andy

 

Hi Andy,

 

There's a reasonable chance those long decay times down low are caused by resonances that are  "minimum phase".

I always struggle to explain what "minimum phase" actually means - but a key feature of a "minimum phase" resonance is that it can be corrected with EQ in both the time domain and the frequency domain.

ie pull the peak in amplitude down with EQ and you will also shorten the reverb/decay time.

 

If you look at one of @Rustee's earlier posts, there's a big peak in the amplitude/frequency response just above 40Hz.

On 14/09/2022 at 8:59 PM, Rustee said:

 

 

A 40Hz peak like this would require specialist treatment - but there's at least a reasonable chance it will be minimum phase - and REW can measure minimum phase!...

https://www.roomeqwizard.com/help/help_en-GB/html/minimumphase.html

https://www.roomeqwizard.com/help/help_en-GB/html/graph_splphase.html#:~:text=Minimum Phase%2FExcess Phase&text=The minimum phase trace shows,the measured and minimum phase.

 

...and if that peak is minimum phase, then a band or 2 of EQ cut will bring the peak down and reduce the decay/reverb time.

 

EQ has a (deservedly) bad reputation - through poor application - EQ can do great evil!

Well applied, IMHO EQ can do great good to the "in room" sound - especially under 100Hz where room peaks are more likely to be "minimum phase".

 

There's a very good reason for the approach of only using EQ "cut" and not EQ "boost".

Peaks in the amplitude/frequency response are more likely to be "minimum phase" (but not always), and EQ cut will benefit where the response is minimum phase.

Dips in the amplitude/frequency response are rarely "minimum phase", and EQ boost will not benefit if the response is not minimum phase.

 

On 29/10/2022 at 3:37 PM, almikel said:

Reducing reverb further above 1K is easy - only thin absorption is needed.

 

4 hours ago, Rustee said:

And denser?

I never ended up getting my hands on any denser absorption than the HD50, so never got to experiment. 

Denser is not required - HD50 is fine for absorbing higher frequencies...

...In my approach to room treatment I've always focused on the bottom end, ie getting the room's bass under control.

By the time I've added sufficient absorption targeting the room's bass response (ie straddling corners and avoiding 1st reflection points), I never need additional absorption for the top end - usually the opposite. ie covering the corner absorption in slats or plastic to reflect treble back into the room.

 

3 hours ago, Nada said:

Please can you help me understand why its better to do the room treatment and not EQ?

 

I dont know much about the field but would have assumed EQ would be easier to do and the priority?

Hi Nada - I'm still using the USB to SPDIF converter I bought from you - thanks!

 

EQ is minimum phase - so it only helps to fix room issues that are minimum phase.

Try to fix a room issue that's not minimum phase with EQ and you will "at best" fix the issue "at one position" in the room at the expense of making the the sound poorer "everywhere else" in the room.

 

OTOH, absorption room treatment will absorb as it was designed - it doesn't care about minimum phase - it just absorbs sound above it's design frequency, and will never make the sound "worse" in a different part of the room...

...but too much absorption treatment can make the room sound "dead", which is why I avoid placing treatment at lateral 1st reflection points during the process of getting the room's bass under control.

 

Typically and fortunately, under 100Hz or so, the rooms I've treated have had a minimum phase response, and EQ has worked very well in managing issues < 100Hz where absorption would get ridiculously large - I've never tried to manage the bass in a "rigid" room - it would be a nightmare

 

I love EQ/DSP, and IMHO it's indispensable for proper mains/sub integration, but it's not a substitute for room treatment ~100Hz - ~500Hz where lots of non-minimum phase stuff is happening in the room.

I've found EQ very useful in addition to room treatment, particularly below where the treatment is effective.

 

cheers,

Mike

Edited October 31, 20223 yr by almikel
clarification

6 hours ago, Nada said:

has say +6dB in the mids  it seems like the first thing to do is fix the source. Trying to fix a problem like that with room treatments seems like hard work and the direct sound will still be hot.

That does seem completely logical ( and I think a few others also suggested EQ'ing that top end a little first). But for now it was more just trying to get what I have now sounding better without any additional gear.

 

6 hours ago, Nada said:

I dont remember you saying what your speakers are. Do they have  a tweeter XO around 3kHz by any chance with a rising response?

Monitor Audio Silver 8.

 

From the MA spec, the MF-HF crossover is at 2.7K .

 

Not sue if they have a rising response, from these Stereophile tests, there does appear to be a few peaks?

 

Cheers,

Russ

5 hours ago, almikel said:

Denser is not required - HD50 is fine for absorbing higher frequencies...

...In my approach to room treatment I've always focused on the bottom end, ie getting the room's bass under control.

By the time I've added sufficient absorption targeting the room's bass response (ie straddling corners and avoiding 1st reflection points), I never need additional absorption for the top end - usually the opposite. ie covering the corner absorption in slats or plastic to reflect treble back into the room.

Thanks @almikel.  Glad I didn't spend a fortune on high density absorption! 

 

And thanks for the post above in response to @andyrand @Nada, whilst it makes my head hurt trying to understand it, it's informative posts like this that become priceless for people (maybe me one day) who are giving EQ a go.

 

Cheers,

Russ 

9 hours ago, almikel said:

Hi Andy,

 

There's a reasonable chance those long decay times down low are caused by resonances that are  "minimum phase".

 

...a key feature of a "minimum phase" resonance is that it can be corrected with EQ in both the time domain and the frequency domain.

ie. pull the peak in amplitude down with EQ and you will also shorten the reverb/decay time.

 

If you look at one of @Rustee's earlier posts, there's a big peak in the amplitude/frequency response just above 40Hz.

A 40Hz peak like this would require specialist treatment - but there's at least a reasonable chance it will be minimum phase - and REW can measure minimum phase!...

https://www.roomeqwizard.com/help/help_en-GB/html/minimumphase.html

https://www.roomeqwizard.com/help/help_en-GB/html/graph_splphase.html#:~:text=Minimum Phase%2FExcess Phase&text=The minimum phase trace shows,the measured and minimum phase.

 

...and if that peak is minimum phase, then a band or 2 of EQ cut will bring the peak down and reduce the decay/reverb time.

 

Thanks for that, Mike - makes perfect sense! 

 

I will have to examine my own REW graphs. 

 

4 hours ago, Rustee said:

from these Stereophile tests, there does appear to be a few peaks?

 

Do you hear a hot >3k still. Kind of a piercing quality?  Turn it up and the ears bleed sort of thing?

In the right system correcting the lift over 3K could make a dramatic difference.

 

If you are streaming its super easy to EQ.  Have fun

1 hour ago, Nada said:

Do you hear a hot >3k still. Kind of a piercing quality?  Turn it up and the ears bleed sort of thing?

Yes I do. Not on all music but say for example some music with lots of electric guitar or music that is already on the higher pitched end of things - yes can sound piercing.

 

1 hour ago, Nada said:

In the right system correcting the lift over 3K could make a dramatic difference.

 

If you are streaming its super easy to EQ.  Have fun

Ok you have my attention! I do have a basic streamer set up (RP4 into ifi Nano DAC). We only stream from Spotify at the moment.

 

I'm very interested, if there's a super easy way to have a play and try it out. Please elaborate!

 

10 hours ago, Rustee said:

yes can sound piercing.

 

That brings back bad memories for me from way back pre-software EQ days. A three way I tried did that hot shrill thing from the cross over I dont think it was that loud but the more I heard it the  worse it got. Speakers were returned.

 

10 hours ago, Rustee said:

basic streamer set up (RP4)

 

You are running Linux.? Which distro do you use on the Pi?  Thats pretty advanced IT skills you have. Should be easy to install a good EQ and bring down the high SPL bands. 

13 hours ago, Nada said:

You are running Linux.? Which distro do you use on the Pi?  Thats pretty advanced IT skills you have.

 

I don't know what software was used. My son is the one with the advanced software/coding skills - I would still be trying to work it out.

I will find out and come back to you.

 

Hi @almikel - I'm wondering which graph-type with RT60 I should've selected for my RT60 graph?

 

Here is mine - including several graphs:

• Topt
• T20
• T30
• TS
• and EDT.

 

 

Is my 'EDT' graph the same as what Russ selected, here (the green line)?:

 

 

 

Thanks,

Andy

 

21 hours ago, Nada said:

You are running Linux.? Which distro do you use on the Pi? 

@Nada This is the info I got from my son.

It runs on standard raspberry pi os/raspbian which is unix based. It is basically a Spotify device.