Added 10 RPG MODEX 35HZ-500HZ Panels to room and zero improvement.

[keenly]

Hi everyone

I have recently moved into converted garage-bedroom in Northumberland, UK. Pics show room.

I have been researching audio treatment for 2 years now and made the decision to purchase some some panels before moving. I presumed, based on what I thought I knew, that these would smooth the bass out. I watched many Dennis foley videos and he says every small room has issues with 30-100hz. I could not find anything in the UK to go down to 30hz, but RPG go down to 35hz. I figured these would not deaden the room so no harm could be done.

I intend on setting up 7.2.4 Atmos system, but only have a 2 channel one right now. I have rel subs and have tested 1, in 1 position. This was just before putting panels on wall. Bass is almost non existent on left side of mlp, particularly when stood up, and right side of room has excessive bass.

I have got my brother in law to put up 10 panels for me. Mostly on front and back walls where I believed most pressure would be. The front side walls in corners also have panels; left and right. I can post pics later(right now there is stuff everywhere).

The £5000 I have spent has not helped one bit. Bass sounds worse than last room which was same size and had no treatment. I am totally devastated by this. Bass is all over the place and music is not enjoyable at all.

Any thoughts would be appreciated, cheers.

 

[mep]

Are you running both subs now or just one?

 

[AJ Soundfield]

What type of music do you listen to and do you own a smartphone?

 

[u-sound]

hi keenly, sorry to see you unhappy after all your efforts.

i think it is a good thing to watch mr. foleys videos. he is an absolute expert.
the problem comes when you want to apply this knowledge to your room, since very few people can or want to buy his diaphragmatic bassabsorber. they will take a lot of space and cost something like 50k to do a room....
what you really can take from him is that all the 6 walls create the challenge.

and yes, small rooms is more of a problem and towards quadratic as well.
what panels did you buy exactly? i just guess these are membrane absorbers. you have to know that these have a very narrow bandwith where they are effective. and on top they are hit or miss. if you dont put them where the pressure is, then they are pretty useless.
when AJ ask you about a smartphone, i guess he means you should walk around in your room and measure where the pressure is.
well, still then, little is done. 30 or 35hz is usually not the biggest problem. to understand, a certain single frequency peak or null is not very hearable. the big problem is between 60 and 100hz where you have a lot of frequencies close together with an issue. for example everything from 65 to 75 gets cancelled.
here is a calculator that makes it a bit visual what goes on in your room and where.
amroc - THE Room Mode Calculator

the ceeling is always a main problem. if you are willing, you could cover it with
GIK Acoustics Scopus Tuned Bass Trap (T70) - GIK Acoustics
they are only 10cm and do a good job as long as you put enough there.

then, each corner an active bassabsorber
AVAA C20 - Active Bass Trap - PSI Audio

unfortunately expensive. then again very effective, a friend of mine has a similar sized room as you with a too big speaker (old wilson grand slam), it was horrible but the combo of the gik ceeling and 4xavaa made things ok.

another thing, once you furnished your room, it will sound different. maybe good enough?

 

[sb6]

Sorry to hear your treatment is not helping as you intended. I would recommend learning how to use REW or hire someone or ask someone who knows how to use it to measure your room. between the treatment and the sub you can yield better sonics if applied appropriately. Without measuring in some capacity, it is difficult to know where to best place treatment other than the usual corner locations which might be a good starting point. Listen w/o treatment, then listen with corner placements.

Also, I would take D.F.'s advice with a grain or 3 of salt as his recommendation in most videos is that if your room isn't ~>400 cu ft then you need to build a new room, hardly practical advice for most audiophiles.

 

[keenly]

hi keenly, sorry to see you unhappy after all your efforts.

i think it is a good thing to watch mr. foleys videos. he is an absolute expert.
the problem comes when you want to apply this knowledge to your room, since very few people can or want to buy his diaphragmatic bassabsorber. they will take a lot of space and cost something like 50k to do a room....
what you really can take from him is that all the 6 walls create the challenge.

and yes, small rooms is more of a problem and towards quadratic as well.
what panels did you buy exactly? i just guess these are membrane absorbers. you have to know that these have a very narrow bandwith where they are effective. and on top they are hit or miss. if you dont put them where the pressure is, then they are pretty useless.
when AJ ask you about a smartphone, i guess he means you should walk around in your room and measure where the pressure is.
well, still then, little is done. 30 or 35hz is usually not the biggest problem. to understand, a certain single frequency peak or null is not very hearable. the big problem is between 60 and 100hz where you have a lot of frequencies close together with an issue. for example everything from 65 to 75 gets cancelled.
here is a calculator that makes it a bit visual what goes on in your room and where.


the ceeling is always a main problem. if you are willing, you could cover it with
they are only 10cm and do a good job as long as you put enough there.

then, each corner an active bassabsorber


unfortunately expensive. then again very effective, a friend of mine has a similar sized room as you with a too big speaker (old wilson grand slam), it was horrible but the combo of the gik ceeling and 4xavaa made things ok.

another thing, once you furnished your room, it will sound different. maybe good enough?

Thanks for input

The modex Plate 2 that I have should deal with 35hz-100hz

These are the Sound Absorption Coefficients

32.5 has 0.61
63 has 0.98
125 has 1.06
250 has 0.89

 

[keenly]

What type of music do you listen to and do you own a smartphone?

Hi
All types, mainly multichannel, lots of rock. Lots of Atmos titles.

I do not use a smartphone but there's a bunch in the house from other people.

 

[AJ Soundfield]

Hi
All types, mainly multichannel, lots of rock. Lots of Atmos titles.

I do not use a smartphone but there's a bunch in the house from other people.

Ok, starting with the latter, that means you have access very basic measuring capability, While I wouldn't design a speaker with one, a smartphone can measure reasonably accurate in the bass range, with exception of lowest frequencies. With a very inexpensive mic like this Dayton all bass can be measured, to find out where the most offensive frequencies are.
Regarding the former, music types, that means monophonic bass. The best solution there is multiple subs. At least 3. They don't all have to be large/expensive either. With bass/output spread across 3 or even 4 sources, you will have much smoother bass throughout room and at least on bed, with less strain/output capability needs on each sub. There are many ways to approach this, but since you've already spent (wasted?) 5k, using a decent MCH AVR/Pre seems likely and those will offer a built in multi-sub optimizer, with onboard room measurement/EQ. The smartphone can be used in conjunction, or not at all.


cheers,

AJ

ps here is an article with examples.Just a moment...

 

[keenly]

Ok, starting with the latter, that means you have access very basic measuring capability, While I wouldn't design a speaker with one, a smartphone can measure reasonably accurate in the bass range, with exception of lowest frequencies. With a very inexpensive mic like ] all bass can be measured, to find out where the most offensive frequencies are.
Regarding the former, music types, that means monophonic bass. The best solution there is multiple subs. At least 3. They don't all have to be large/expensive either. With bass/output spread across 3 or even 4 sources, you will have much smoother bass throughout room and at least on bed, with less strain/output capability needs on each sub. There are many ways to approach this, but since you've already spent (wasted?) 5k, using a decent MCH AVR/Pre seems likely and those will offer a built in multi-sub optimizer, with onboard room measurement/EQ. The smartphone can be used in conjunction, or not at all.


cheers,

AJ

ps here is an article with examples.

Thanks for input, I will use DSP at some point.

I think I need some tuned 70hz traps on ceiling, which is normally a problem(70) for 8ft high rooms. Then 2 subs plus EQ.

 

[Bjorn]

Modex plates work well. We've used them for years with success. But placement is key and measurements needs to be conducted both before and along the way. And it generally would have been recommended to split the bass traps into several types. So instead of going with 10 units of the Plate type 2 (35-100 Hz), for example use 4-5 of the Modex plate type 1 (50-500 Hz) and also combine the units with some treatment on the outside to make them more broadband.

It takes knowledge to treat a room, and especially the lowest frequencies with pressure based traps. The first step is mesasurements, so can knows specificially what to address. If not, one is going in blind.

 

[Bjorn]

I strongly disagree that multiple subwoofers is the best solution. Multiple subwoofer/EQ only work in a limited frequency area. It doesn't always address the time domain behaviour it works in. It doesn't deal with harmonics like treatment. It's limited to a smaller area of the room. And opposing subwoofers operating in the same frequency area have negative effects with loss of pressure. Personally I also find that many multiple subwoofer solutions generally sounds more messy with the bass not being as well integrated as compared to having one or two subwoofers in the front close to the fronts, but this will depend on the method and placements.

However, using multiple subwoofers is an easier route to even frequency response. With treatment, it takes more knowledge and often large surface areas needs to be treated. But the latter gives a much better result because it addresses a wider frequency area and works both in the time domain behaviour and all of the room.

But it comes down to what's practial possible and budget. A possibillity is also to combine both if large surfaces can't be treated for practical reasons. Having no treatment and only multiple subwoofers basicall means a very poor bass/lower midrange definition in the important frequency area of 100-300 Hz.

 

[brodricj]

Can you please explain "time domain". That is time alignment of different sources at the listening point?

 

[Bjorn]

Can you please explain "time domain". That is time alignment of different sources at the listening point?

In this matter we are primarily talking about how the bass decays in the room when we talk about the time domain behaviour. Though other aspects can also be related to the time domain.

Frequencies will decay and when this takes time with low frequencies, they are ringing or sustaining longer in the time domain. This causes a low quality of bass frequencies with build up energy that "booms" and resonates.
One way to look at this is using the cumulative spectral decay graph. This shows us both the amplitude of the frequency and how it decays over time.

 

[keenly]

Small listening rooms can be a huge challenge acoustically. I tussled for ages trying to flatten peaks at 35hz and 60hz and a trough at 50hz. Not much can tame a 40hz peak - passively at least - but I found GIK Scopus tuned bass traps useful with bass overhang and decay times. I wrote about my experience with measurements in my system thread. Link is below if you are interested to read.

I can not see link?