Creation of dedicated listening room

[tuga]

In Scotland - 'Dwang' = noggin, or patress (England).

Actually my very fave bit of Scots site usage is a ' a Slapping' = what the rest of us call a 'builder's work opening' i.e. a hole for service penetrations etc.

A patress is a ply or chipboard panel fixed behind the plasterboard:

 

[Tarzan]

I've never hear that term, only nogging.

Yep, only ever heard them called Nogging as well, might use the term 'dwangs' from now on.

 

[IanW]

The fact is that you only know if you need Helmholtz resonators or bass traps (also their bandwidth) if you measure.

I would ask @Sonority to go and visit his old factory and listen to the rooms that he has converted to get an idea of what he has achieved (it is quite amazing).

You do not need to measure the room to know if you need Helmholtz resonators. You can play steady state tones at 50 Hz in 5 Hz steps up to 150 Hz and if any of the tones stand out and you can feel the room resonating, then, if you want to, you can reduce that resonance with tuned Helmholtz resonators.

My room was tuned with Helmholtz resonators by an acoustician who used a measurement system to excite the room (loud random noise) and then looked at the RT60 characteristics to decide on Helmholtz tube length.

I have then used the steady tone approach to tune it further and am in the process of building acoustic frames with 50 mm insulation to deal with higher frequency reflections.

What I am really saying is that there are multiple ways to reduce the in room distortions.

 

[tuga]

I would ask @Sonority to go and visit his old factory and listen to the rooms that he has converted to get an idea of what he has achieved (it is quite amazing).

You do not need to measure the room to know if you need Helmholtz resonators. You can play steady state tones at 50 Hz in 5 Hz steps up to 150 Hz and if any of the tones stand out and you can feel the room resonating, then, if you want to, you can reduce that resonance with tuned Helmholtz resonators.

My room was tuned with Helmholtz resonators by an acoustician who used a measurement system to excite the room (loud random noise) and then looked at the RT60 characteristics to decide on Helmholtz tube length.

I have then used the steady tone approach to tune it further and am in the process of building acoustic frames with 50 mm insulation to deal with higher frequency reflections.

What I am really saying is that there are multiple ways to reduce the in room distortions.

Sure, there are multiple ways to reduce the in-room distortions: bass traps, resonators, midrange and treble absorption, deflection and diffusion.
I would rather use something more accurate than 5Hz steady-tone steps and my hearing, as does your acoustician.

 

[Mike Reed]

Maybe called "pattress box" because they are normally fixed to a pattress behind the plaster? As opposed to a "surface mount" box.

Maybe indeed, as the word, presumably being too technical, isn't listed in my New O.E.D. in either spelling, but one t simply doesn't equate with the pronunciation. Mine, which were sold to me as pattresses (double t), are very much surface mount and are the same dimensions as the old (?) surface-mounted double sockets as often fitted to skirting boards.

As @tuga says overleaf, the name applies to the sheets between uprights in a stud wall, but he uses only one t.

As we have a number of electricians on here, maybe a definitive appellation can be found., though your 'pattress box', as fitted to (reinforced) stud walls, makes sense.

Constructing one's own auditorium is, I'm sure, sth many have dreamed about. Actually building one from scratch being the ultimate achievement. Even converting a garden shed to a listening room complete with armoured cable under the garden, as someone on here did many years ago, is quite sth, I feel!

I've only succeeded in 'converting' living rooms/dining areas etc. into hifi rooms, with my current place needing two lengthy building jobs 5 years apart, ending with weird room dimensions of 9' +, widening to 15' the narrowing to 14' where the kit is by taking some of the hall away, but at least I can access to the many pieces of kit from behind and still have a 7' sofa and access each side to the bay window and record alcove.

 

[sq225917]

If you measure it you can get all the peaks and troughs, calibrated, in about a minute, rather than making multiple complex passes and still having to guesstimate the absolute levels.

 

[dspatterson]

Progress

 

[dspatterson]

 

[sailor]

If you measure it you can get all the peaks and troughs, calibrated, in about a minute, rather than making multiple complex passes and still having to guesstimate the absolute levels.

Thanks 'bit of this, bit of that' you saved me typing the same thing.

Helmholtz resonators work extremely well but they are virtually DIY only. Also if you did know someone who could calculate and build one to a specific frequency, it's only measurement that would let you know if it was sufficiently large enough to do the job and that's presupposing you knew where to place it to start with and would like that particular spot.

As I mentioned in my earlier post multi-subs can solve your bass issues. Above the Schroeder frequency, typically around 250 to 300 Hz is a reverberant field and is easily controlled with broadband absorbers. Here again measurement will show if you have sufficient or perhaps too much. RT60 tables available online will provide a target. Below Schroeder is the troublesome region and measurement really is your friend.

Some throw up their arms when subs are mentioned but I regard them as tuning devices, not to produce thunderous bass but to lower the peaks and fill in the nulls. Some will suggest EQ but although it can lower the peaks it can not fill in the nulls. Bass waves combining out of phase cause nulls and partial nulls and boosting power into their frequency will just cancel with the same power.

This all may seem somewhat daunting but I assure it is not and once you get started measuring it is a lot of fun. If you introduce a sub I recommend choosing a sealed enclosure as they are simpler to dial in. One of my subs is a small SVS SB1000 which conveniently allows you to control all settings from your listening position while watching the result on your laptop. Fascinating stuff, you get to see the peaks reduce and the nulls fill in as you adjust settings on your phone. Whatever sub you choose it is essential to have variable phase and as mentioned go for a sealed box design.

There is more to this than just a smooth response. Consider a full null, this is a music black hole so yes that's info missing, info fundamental to a complete sound. Of course you get to realise and enjoy tight tuneful and detailed bass with no overhang. You have probably heard it said before that everything improves, well all those lies are true. If you can manage 2 subs setup becomes easier and smoother. I currently have only 2 the other being a small REL with me preferring the cheaper SVS. These 2 subs fill, with headroom to spare, my 5m x7m room to concert levels. I enjoy a full rich immersive sound that I don't believe can be achieved at any price if not taking cognisance of acoustics and augmented with subs. I use OmniMic V2 to measure which is now discontinued. A newer updated version will be released later this year but it's not free, I paid $300 but the free REW does exactly the same.

 

[wulbert]

It’s very clean! Ceiling off too, you’re not messing about.