Room treatment, DIY?

[conkerman]

I have recently bought a NAD T778 and Running Dirac has shown me something I have been aware of for a while, My room is a bit of a nightmare for bass, there is huge spike in Bass around 40Hz.

Now Dirac has done a good job here, but i do wonder if adding some room treatment would be helpful here. Does anyone here have any experience of bass traps and Diffusers?

I was thinking of making some DIY bass traps backed up by some diffusers on the wall behind the listening position. I'll probably buy some diffusers as they might be tricky to make and perform well.

We are gearing up to decorate the Lounge and it is a good opportunity.

[Some Gump]

Not familiar with dirac (been out of industry for a long time).. But with bass, it's often peaky as hell in different positions. Move the mic 2 foot and you might see a really different thing! We used to use 5 at different heights around the general listening position then average them out.. We'd then eq from there.

Now re. Room treatment, ime sort out your top end things sound good. Avoid slap echoes, plenty soft furnishings where possible / make the walls somewhat irregular; if client wants solid floor, minimalist and leather ask them to shop elsewhere

[Crackie]

conkerman said:

I have recently bought a NAD T778 and Running Dirac has shown me something I have been aware of for a while, My room is a bit of a nightmare for bass, there is huge spike in Bass around 40Hz.

Now Dirac has done a good job here, but i do wonder if adding some room treatment would be helpful here. Does anyone here have any experience of bass traps and Diffusers?

I was thinking of making some DIY bass traps backed up by some diffusers on the wall behind the listening position. I'll probably buy some diffusers as they might be tricky to make and perform well.

We are gearing up to decorate the Lounge and it is a good opportunity.

Good post from Some Gump.

The in room response is complex..........the 40Hz peak may be severe where you've made the Dirac measurement but it may be very different when measured elsewhere. It should be possible to reduce / mitigate / ameliorate the effect by slightly adjusting the speaker(s) position relative to room boundaries. Small positional changes can make huge subjective differences below the Schroeder Frequency https://www.soundandvision.com/content/schroeder-f...
If the speaker's distance to the rear wall, side walls, floor and ceiling are multiples, from a harmonic frequency point of view, they can combine to give large peaks like the one you are experiencing. A small positional change may generate a null rather than a peak and limit the peak.

On a positive note............peaks are better than nulls. Dirac will cut the signal amplitude at that frequency..........this gives the amp's power stages and the speaker drivers a far easier time. Conversely if Dirac tries to fix a null in the room response the amp pushes more watts to the speaker, driver excursion increases, voice coils get hotter ( power compression ) and all the while the room is still trying to cancel out all the extra work from the amp & speaker.

Which speaker model do you have?

[conkerman]

Thank you all.

I currently am running Qacoustics 2050i/2020i/2090i and a b&w sub.

I am planning to replace the LCR speakers and maybe the sub too, in the next few months,

My room has hard floor with a large rug and plenty of sofas and chairs. It does have a 3.2m window running along the left wall ( looking at the system, although there are blinds and curtains) the room is quite lively, but not a total echo chamber.

[Douglas Quaid]

Acoustic panels are not difficult to make. If you’re not good at diy you can buy them. Even the 100mm thick ones don’t make much of a difference to bass but they can make the top end much clearer by reducing ringing and from your main speakers. Certainly worthwhile to have some at point of first reflection at least.

To tame your peak you’d be better off trying different positions with your subwoofers, room treatments won’t do a whole lot for a 40hz peak unfortunately.

[Crackie]

conkerman said:

Thank you all.

I currently am running Qacoustics 2050i/2020i/2090i and a b&w sub.

I am planning to replace the LCR speakers and maybe the sub too, in the next few months,

My room has hard floor with a large rug and plenty of sofas and chairs. It does have a 3.2m window running along the left wall ( looking at the system, although there are blinds and curtains) the room is quite lively, but not a total echo chamber.

Hi,
The 2050i is a pretty large speaker, Q Acoustics' spec say they go down to 44Hz. It's important to make sure the B&W high frequency cut off is adjusted to make sure it is only working below that limit; it's possible that the B&W are overlapping too much and duplicating their efforts in the 40Hz region.

If the sub is already set at its lower limit then moving the sub to the optimum position, relative to boundaries, is likely to help enormously.

If you do decide to go down the route of absorbers, this site has some very helpful information, and calculators, to assist you regarding bass traps, absorbers. etc http://mh-audio.nl/Acoustics.html#top

On the same page there are details of diffusers which will help with early reflections and the "quite lively" room you have.

Good luck.

Edited by Crackie on Saturday 14th August 14:26

[minimalist]

Have a look at the GIK acoustics website. LINK

I was digging around the minefield of room acoustics and this company kept popping up. They have a facility on their where you can build a mock-up of your room to help identify what you might need. Another service they offer is to interpret the output of Room EQ Wizard (REW) room analysis software. The software and analysis is free as they are counting on you buying some product.

In the end I bought 7 "spot" diffuser/absorbers and 3 "monster" bass traps for around €650. They can be orders with a range of Camira fabrics so easy enough to colour match them so they don't look awful. I might get a few more bass traps but so far the difference is noticeable and I have a fairly flat frequency response from 35Hz to 20kHz, although I have a 100Hz dip to contend with

Link to room acoustics visualiser

[Ian-27xza]

I had 2 of these in a former room and they were surprisingly good at improving the clarity of my music in my room. They toned down the 'boomyness'.

https://www.mafiapanels.com/product-page/2x-mafia-...