Promoted Room Treatment – This Year's Snake Oil?

Thanks Rob, I'd love to pop over at some point, but I recently had a home demo for a couple of weeks of an MP50.

As point of reference, my room is 4.6m x 3.3m, no windows, no alcoves, perfectly symmetrical, I sit 30% away from the back wall and my subs are located in the rear corners (they're too big to fit up front). Whilst I had the Mp50, I did a few measurements to give me an idea of what room perfect was doing.

This first image is my 2 subs uncorrected, my Arendal sub3s are good down to around 17hz, but due to the limitations of the positioning of them, I have large null around 25hz and another one around 32hz, but my overall response is pretty good:
sub 1 and 2 comparison no eq.jpg


After running room perfect, I managed to achieve the following result, you will see that the frequency response has been smoothed out pretty well, but I still have a big null at 25 and 32hz and surprisingly another one now at 72hz that wasn't too bad previously; room perfect simply couldn't EQ these out.

mp50 corrected response.jpg


So, after returning the MP50 and doing some thinking, I added a smaller Arendal Sub1 (I've actually got a another one on the way to me) behind my screen (after using REW room sim) to try and help with these nulls, I also ordered a minidsp.

These are my new results:
3 subs plus minidsp.jpg


I think it is quite obvious that adding the 3rd sub with minidsp has given my a much better response, with now only a 1db dip at 23hz, the rest of my response is almost ruler flat.

This therefore suggests to me, that room placement is absolutely critical to help with the response in the room, but more so, below are the waterfall graphs from both the MP50 with 2 subs and 3 subs with my Marantz 8805 using Audyssey XT32 and a minidsp, again, room perfect is showing more ringing higher up the curve which tells me it isn't doing as good a job here either.

The bass sounds much better now.

MP50 waterfall.jpg
3 subs waterfall.jpg
 
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Thanks for such extensive feedback. You can’t argue with those graphs and I’m sure it sounds much better.

I’d love you to come over when you can to assess the systems here that all sound fab with front woofers in the corners as described.

I did calibrate one system last year where I wasn’t thrilled with the bass using this method, but is was an exceptionally long room and the seating position was right in the middle. Moving the subs would have made a huge difference but it just wasn’t possible because of the decor.

My guess is that your very small room and seating position can only be fixed with multiple subs which you have obviously done. Most of the rooms I see are much bigger and this method almost always works in these spaces.
 
In layman’s terms, how does Room Perfect create stereo base if those frequencies are directional? I don’t doubt it works, I’ve heard Rich’s room and read Steve’s recent review just intrigued.
 
When you tell a Lyngdorf TDA stereo amp or Surround Processor you have a pair of subs placed left and right in the room, it will send the bass from the left speakers to the left sub and vica versa. This gives stereo bass and very even bass from every speaker around you.

This is an interesting video on the subject from David Greisenger, ex Lexicon.

He says stereo bass is essential in classical recording and is very easy to hear with headphones

Most studios use mono sub – but shouldn’t

 
Interesting video Rob, love to be able to have subs raised off the floor but they weigh a ton!

Are the boundary subs designed differently to normal sealed subs like mine? Just wondered as the video claimed that they are designed for corner placement, so maybe mine would not have same effect in that position.

Marty
 
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Hey Marty

The key difference between boundary woofer and subwoofers is what they are designed for.

Subs are designed to give maximum output below 100Hz. To do this, they have very big drive units that are ideal for the special effects in a film.

Lyngdorf developed boundary woofers over 20 years ago for use in the finest music systems where speed and timing are the main concerns. The drive units are designed to start and stop as quickly as possible. Creating bass isn’t hard, making it stop quickly is the challenge. If you listen to music with good transients with a sub, it doesn’t have the attack or speed that it should because the massive drive unit cannot stop quickly enough.

If you compare a Lyngdorf boundary woofer against a sub I’m sure you’ll find its better for music and sounds more natural.

The real transformation comes when you use a pair of boundary woofers, ideally placed in the front corners of the room and calibrated with RoomPerfect. When you do this, you can take advantage of their full bandwidth. The BW3’s for examples play up to 800Hz!.

Try listening to House of the Flying Daggers or the Sheffield Labs Drum & Test CD in a system setup like this and you’ll hear a quality of bass that I’ve never heard with regular subs or speakers.

I’m hoping for bigger, more powerful boundary woofers within the next 12 months.

Come for a listen if you want to hear systems set up in this way........
 
No, its the design of the cone that I think makes the main difference.
 
What frequency do the boundary subs go down to?

So it's not part of their design that makes their ideal position the front corners, basically you believe it's the best position for all subs?

Marty
 
There are several different boundary woofer I use. The LS and LSR212 ones in Steinway systems go to 20Hz, but in cinemas they are typically stacked to fill huge rooms or to play much lower. There was a 350-seat cinema in the US using this approach for example.

The much smaller Lyngdorf ones go to 30Hz but there are bigger models planned.

I think that if you place your subs based on the best frequency response and this puts them say ¼ down the length of the room, you won’t have the best timing or attack. This cannot be corrected with treatment or electronically and is why many systems with great subs don’t sound lifelike.

Placement of a pair of subs in the front corners corrected with RoomPerfect is the only way I know of to be sure of the best timing and attack.

 
For music listing the problem with DSP is ADC -> DAC conversion. DSP quickly becomes the weakest link.
 
Lyngdorf TDA (true digital amplifiers) are essentially DAC’s with a volume control. This maintains the digital signal for longer so less noise and distortion is added. Try one and you’ll hear your music is cleaner and clearer and more detail is revealed.

The errors created by the room are far greater than any created in the electronics. Room errors are typically 15 -20db which means some sounds will be heard 4 times louder than others.

Run RoomPerfect and these errors will be removed. The differences with it turned on and off are usually so big you’ll hear it from the room next door.
 
Hi Rob,

Sorry to drag up an old thread but I do find it very interesting and have a related question.

Is the overall conclusion voiced in this thread, i.e. that room treatments are overused and over sold, mainly aimed at the higher end market where I think the majority of your business is? I understand the premise that systems such as Room Perfect can, in many rooms, mean you may need little to no treatment. I visited Rich as Seriously late last year and heard this for myself in his demo room.

For those of use using more affordable processors or AVRs from the like of D&M, is it fair to say that in these circumstances it is far more likely that some level of treatment would be needed or would be beneficial?

Many thanks
 
Ah almost forgot this thread. Out of curiosity i asked opinion from one big name US specialist who has done zillion treatments to many cinemas, studios etc. He`s reply after seeing the first post was quite clear that Rob is marketing hard and Steinway Lyngdorf seems to be the answer to every problem. :) He posted few things the room correction can´t touch and what is important in home theater, but i won´t post the reply as he haven´t come to talk here. He agreed with Rob about using wrong type materials though.

For those of use using more affordable processors or AVRs from the like of D&M, is it fair to say that in these circumstances it is far more likely that some level of treatment would be needed or would be beneficial?

Have you read this @Smurfin great post yet?
 
Hi Harkon

Room treatment is misunderstood and often does more harm than good, so I’m very happy to give my thoughts on it.

You need to address your rooms acoustics if it’s too live. If for example it’s difficult to hear each other clearly when there are any other sound sources, then yes, treatment will help. Most UK cinema rooms are carpeted and have big sofas that will stop the space being excessively live.

If you have a very narrow room, you also have to reduce the amount of reflections off the side walls, if not then you probably don’t need treatment.

Where treatment is necessary its essential to be clear what you are trying to achieve.

What do you think is wrong with your room?

Most companies selling treatment treat it like its magic and will make everything sound better which is nonsense. Covering all the walls in treatment will absorb mid and high frequencies very effectively while having no impact on the bass. This will ruin the characteristics of your speakers and make the room sound dead and lifeless.

A well know and highly regarded “acoustic guy” in the USA has done a complete U turn on his recommendation. He used to cover all the walls in treatment. He now recommends no more than 15%.

Since I’ve been making noises about this to the trade, other distributors are now pushing treatment far less and some have been removing it from their showrooms.

I think this is an area where experience is essential and you should find a dealer who can demonstrate a superb system and then explain any problems with your room and how they can be addressed.

If you want to take the DIY route, I’d experiment with fabric at the first reflection point in your room before spending money on treatments.

FYI I recently saw a video on Darko Audios site with an “acoustic expert” recently who came out with gems such as .2 reverb time is ideal and that “its difficult to mess up a room to make it worse than before”. Both these statements are complete rubbish. If you think someone may be an expert on this subject, I’d recommend you go and listen to some of the rooms/systems they have designed before taking their advice, particularly if they business is selling treatment.
 
Most companies selling treatment treat it like its magic and will make everything sound better which is nonsense.

More magic than any type of electronic room correction in my experience. But only if applied correctly.

Not been here for a while, but when I was looking at it I never saw ANY advice to cover a room completely with treatments.
 
More magic than any type of electronic room correction in my experience. But only if applied correctly.

Not been here for a while, but when I was looking at it I never saw ANY advice to cover a room completely with treatments.

Totally agree with this. Speak to any of the specialists in the field (I have done many of their courses), and they agree that room treatment should be combined with EQ to get the maximum potential from that room. Room treatment does not just mean that you throw lots of absorption in the room, and the best treatment companies will make recommendations based on measurements in the room, but some can be predicted based on room materials, dimensions etc. Just like EQ there is a very specific science behind the recommendations of treatments.

Treatment is not just absorption as is suggested above, you also need to look at diffusion (2D and 3D), and apart from some ill-informed installers, I have never heard a recommendation that you should put absoprtion everwhere in the room. You only treat a small percentage of the surfaces with the different types of treatment.

I would be interested to know who the following are:

A well know and highly regarded “acoustic guy” in the USA has done a complete U turn on his recommendation. He used to cover all the walls in treatment. He now recommends no more than 15%.

Since I’ve been making noises about this to the trade, other distributors are now pushing treatment far less and some have been removing it from their showrooms.
 
Tony Grimani is the "acoustics guy".

Habitech, Pulse, InVision and most distributors I see recommend panels over all the walls which has done more harm than good in many of the rooms I've heard "designed" this way. I tried this 20 years ago and realised the problems it created then.

I'd invite anyone who is in doubt about which approach is better to come and listen to both and to judge results based on what they hear, rather than what they are told. I demonstrate 10 different systems, only one of which has any acoustic treatment.
 
Tony Grimani is the "acoustics guy".

Tony is a nice and knowlegable guy. I have sat through various interviews he has done, and also sat through a course he presented some years ago. I have also used some of his MSR treatment panels.

I am presuming you are referring to this interview:




For a number of years, he has not recommended high levels of absorption (note not treatment but absorption). He goes on to say that you should also look at some dispersion/diffusion too. So we can't call it treatment, as this is like talking about trousers/shirt, and refering to them as clothes, treatment is a blanket name, absorption which you are referring to is a specific subsection. I am totally in agreement that too much absorption is bad, as we need some 'reverb' in the room. We don't it want to be an anechoic chamber, but some absoption is good.

Habitech, Pulse, InVision and most distributors I see recommend panels over all the walls which has done more harm than good in many of the rooms I've heard "designed" this way. I tried this 20 years ago and realised the problems it created then.

The 3 companies you have mentioned there, do not recommend panels over every part of the wall, and certainly not absorption panels. All 3 use independent companies for room solutions. Those solutions are modular, and often placed behind fabric walls (so it is not clear that there are gaps between the treatments). At least 1 (maybe all) of these companies, design the room treatment, based on measurements (via an app), as well as photos, dimensions etc.

I'd invite anyone who is in doubt about which approach is better to come and listen to both and to judge results based on what they hear, rather than what they are told. I demonstrate 10 different systems, only one of which has any acoustic treatment.

20 years ago is a long time in the world of science, AV etc, and thus it may be that the old practices are not the most efficient anymore. You mention you used a company that went bankrupt, so we have no way of knowing whether their approach was the best approach at this time. 20 years ago we were looking at 5.1, 6.1 and 7.1, so we would also need to know what was recommended for your treated room, best practices, and different treatment options constantly evolve.
 
I frequently see plans produced by various companies where the approach is covering all the walls with some form of treatment. I don’t see any science involved, just the assumption that more stuff equals better sound.

If you have any science that these companies produce for their room designs, please post it here.

I encourage people to go and audition as many alternatives as possible before assuming the product or design you are being recommended is worthwhile.

Habitech for example are 10 miles from me and have a Wisdom system with extensive treatment that costs £150k. I believe our MK/Lyngdorf system at £70k sounds far better…….but please trust your ears and go compare.
 
The title of this thread comes across as reactionary doublespeak. Have we built a strawman argument so we could beat it down?

Would be interested to invite the audio expert from Darko's room treatment video to debate the OP on the merits of his inference.

I don't think any honest actor in their right mind would suggest its an either/or situation between room treatment vs eq. To state EQ is the be all and end all for faithful audio reproduction is just as dubious and dishonest as any company selling full on room treatment without careful measurements and standard practices for room treatment.

I suppose the point is there are probably just as many unscrupulous acoustic treatment firms misselling their products as firms pushing EQ integrated system solutions.
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Can anyone recommend a treatment company who will provide appropriate treatments for the room instead of plastering the walls and ceiling? Certainly that would be cheaper than spending 70k on Lyngdorf kit, but at least would be a good starting point.
 
I’m very happy to have a debate with anyone on this subject. I did this for a trade magazine 6 months ago which led to the video posted above.

If you have good speakers in a big good you’ll have good sound. Put them in a small room and sound quality is compromised. By far the biggest problem your room has created is a change in frequency response. No amount of acoustic design and treatment can fix this. If you can show me any design that does, I’ll give you £1000.

Room correction can correct the response of your speakers and there are dozens of graphs on Forum showing this. This is easy to measure and hear.

The starting point of people selling treatment or design is that because you have a room, you have a problem which in nonsense. People have had great sound in their homes for years without either treatment or room correction.

Its very clear that the systems Ricky sells must have treatment for best results. The 10 systems I have here don’t. But the only way you can tell is to Go Compare!
 
Can anyone recommend a treatment company who will provide appropriate treatments for the room instead of plastering the walls and ceiling? Certainly that would be cheaper than spending 70k on Lyngdorf kit, but at least would be a good starting point.


Agree. GIK are good. We have used these for some components before.

If you are after a strectched fabric finish, we use Cinema Build Systems: Front Page -

As addressed above, you will need to look at specifics of the room and equipment, to decide what you need, and how much for the best performance. By going the stretched fabric route of a finish, it gives you great flexibility to add/remove treatment as required at a later date, once you have 'finished' measurements and analysis.
 

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