Quantcast

Lyngdorf discussion

KelvinS1965

Distinguished Member
Well, this won't escalate quickly... hmmm i wonder if Tesco is out of kindling....?
Go on then...I'll bite; I've had a week of looking after my wife and trying not to contract CV from her. I found a bottle of Rum and some flat ginger ale in the back of the fridge, so who knows if I'll make it to the end of this post. :confused:

I keep seeing it mentioned that sound of listening on headphones is supposedly the target to aim for. However, headphones don't usually have any natural reverb and are in fact more like a treated room in that regard. So how does room perfect in an echoey room manage to give a similar result to headphones?

Secondly; regarding the OSD issue: Once you've got your system set up, I reckon all but the completely OCD (who need to keep checking on everything) don't need to have an OSD: I've managed without one for about the last 5 years. Just make sure all the sound modes are set up to respond correctly and set the maximum volume limit, maybe set the maximum 'on' volume too (I assume Lyngdorf gear can do this as well?) then you're good to go.

If you insist on continually checking settings in the OSD, then I'd suggest you're more interested in the tech than the content, so try to break the habit: The gear is there to enjoy films, series, concerts, music, etc. ;)

Since I've made it the end of the post I obviously haven't had enough Rum so stay safe everyone...I'm off to see what else we have in the cupboards since I can't go out for another week to get any sho
 

arisholm

Well-known Member
The biggest problems that rooms create are in the home are in the bass frequencies and no amount of treatment or trapping can correct this. Here is a new thread I’ve just posted that gives more info

Promoted - Room Treatment – This Year’s Snake Oil?
You can also flip this 180 degrees: no amount of room correction software can correct the bass frequencies as it cannot fix room nodes/cancellations (once it is gone, it is gone) or standing waves (which is much related). So if you are serious about bass, a combination of proper bass traps AND digital room correction such as RP is the best approach IMHO. And also moving subs around..
And note there are "bass traps" out there that are not just foam or fiber glass.. ;-)
 
Last edited:

Rob Sinden

Distinguished Member
AVForums Sponsor
I find headphones as a very quick, reliable way of hearing if the frequency response of a system is limited or uneven. Why not give it a try?

You want to use really good headphones, Sennheiser HD25’s are my favourites. Use a variety of music with good bass and dynamics, ideally something quite repetitive. Listen to a few seconds of content of your audio system and then the headphones a few times.

With hifi systems you can nearly always hear the bass extension is limited and the response is uneven. I demonstrate this to visitors here with a TDAi3400/MKIW300/X12 system and the headphones and it sounds remarkably similar with RoomPerfect. Without it, it doesn’t.
 

Rob Sinden

Distinguished Member
AVForums Sponsor
Someone on the Lyngdorf thread (sorry I forgot who) has measured RoomPerfect and other room correction systems in lots of rooms and reported that RoomPerfect can typically restore cancellations up to around 10db. If the cancellation is greater than this, it can’t fix it, but neither can any treatment. It requires re positioning of the seating position or subs/speakers.

RoomPerfect and other correction systems do fix standing waves. You can see this in the measurements and it very easy to hear when you turn the correction on and off.

There are dedicated bass traps but they are not powerful enough and don’t have the resolution required to do the job. If you measure the before and after response of a system with bass traps you’d see they aren’t fit for purpose.

Room correction can rectify the response. Room treatment can’t.

I built a room using 60 bass batts and all it did was remove all the bass. It didn’t even it out in any way. Here is another example of room with very expensive, professionally designed bass treatment and traps that did not work. Go to about 7 minutes in, he says “it didn’t work, we go about a 2db dip in the bass where we needed 10db.”

.......and look at the mess at the back of its room and imagine the expense!


What really counts is that I can demonstrate 10 systems here all of which provide very even frequency response at all frequencies. Lots of people have visited and can confirm this. This isn’t possible with any form of room design and treatment I know of.

If anyone knows of a systems that can restore frequency response, please can they post it here?
 

arisholm

Well-known Member
Hi Rob, I am a big RP fan. It does so many things right, as I have also shown in a lot of measurements posted here during the past couple of years. Yes RP can restore some cancellations. I have shown it. But at the expense of more power and lower headroom + possibly worse decay (if it is attempting to correct a dip in a "room node", although RP is less likely to do that than other RC systems). So I still believe you can benefit from room treatments, but you must treat problem areas, not "pad the room" in random ways, to get optimal results. I intend to measure results of the impact of bass trapping combined with RP as soon as I get my order to RPG bass traps which are optimized from 20-80Hz, peaking at 40Hz. I hope they can fix the problems I have with slow decay at 40Hz in my room. It is not all about frequency response. We'll see.
Keep safe :)
 
Last edited:

Rock Danger

Distinguished Member
And note there are "bass traps" out there that are not just foam or fiber glass.. ;-)
I think we both know what the proper ones are made from.
 

arisholm

Well-known Member
Yeah beeswax to the rescue :cool:
 

StephanG

Active Member
So I still believe you can benefit from room treatments, but you must treat problem areas, not "pad the room" in random ways, to get optimal results.
Full simulation of the room to identify problems is the way to go. It's not cheap though and neither is the software for doing it, there are specialists out there doing it, your dealer should work with those. Just putting treatment into the room does more damage than good.
 

orange55

Well-known Member
Full simulation of the room to identify problems is the way to go. It's not cheap though and neither is the software for doing it, there are specialists out there doing it, your dealer should work with those. Just putting treatment into the room does more damage than good.
Doesn’t @Rob Sinden have a great story about how that didn’t work for him?
 

StephanG

Active Member
Doesn’t @Rob Sinden have a great story about how that didn’t work for him?
Don't know, does he? Who did he use to run the simulations? What software? Could we have a look at the acoustical models to see what happened, maybe something went wrong? What is the noise rating for the room? This has been discussed up and down over the decades with plenty of people in the other two major forums for which it worked, at scientific conferences, etc. To quote Walter Lewin, physics works. At least it did for this guy: Hahn (Theater of the Decade) - Keith Yates Design:D
 

arisholm

Well-known Member
Doesn’t @Rob Sinden have a great story about how that didn’t work for him?
I think we should be careful to think that there is silver bullet, including RP solving all problems... regardless of a good story or even two. There is some physics at play.
 

Rob Sinden

Distinguished Member
AVForums Sponsor
Hi Arisholm

If you have run RoomPerfect and there is still a problem, I’m sure you are right.

My experience is mostly in UK rooms built with brick or Celcon blocks covered with Gypsum. If the room has reasonable proportions and some furniture I can almost always get great sound in these spaces.

I’ve installed a number of cinemas in Greece and Spain and the different room construction create very different acoustics. They are usually obviously overly "live" spaces where mid and hf reflections needed absorbing. Once this is done getting great sound typically isn’t a problem.

I’d love to know more about the size/proportions of your room, its construction, the layout of the kit and any carpets, furnishings etc. Would you be happy to post some photos?

I’m would have thought that bass hanging around at 40Hz would only happen in a basement? Is it an obvious audible problem or just something that shows up in measurement?

Do you have any info on the products that you’ll be using to absorb 40Hz?
 

superflyhifi

Standard Member
I have some frequencies I want to lower between 50-67 Hz as they cause some rattling sound from my lfe speaker. If I do a voicing where I lower these frequencies will this affect the other speakers? I have 80 Hz crossover and Medium speakers in all other places & 2 more subwoofers in the back of the room.
 

Rock Danger

Distinguished Member
I have some frequencies I want to lower between 50-67 Hz as they cause some rattling sound from my lfe speaker. If I do a voicing where I lower these frequencies will this affect the other speakers? I have 80 Hz crossover and Medium speakers in all other places & 2 more subwoofers in the back of the room.
Your speaker shouldn't be rattling tho - When you say LFE speaker do you mean your sub? What sub is it and how did you set it up before you ran room perfect?
 

superflyhifi

Standard Member
Your speaker shouldn't be rattling tho - When you say LFE speaker do you mean your sub? What sub is it and how did you set it up before you ran room perfect?
I have an ICE passive subwoofer with an Earthquake amp. I talked to my dealer and with dirac these two frequencies can be lowered slightly to avoid the rattling. Looking how I can achieve this on the MP-50. So its the LFE not the two subwoofers.
 

orange55

Well-known Member
I have an ICE passive subwoofer with an Earthquake amp. I talked to my dealer and with dirac these two frequencies can be lowered slightly to avoid the rattling. Looking how I can achieve this on the MP-50. So its the LFE not the two subwoofers.
Sounds like the first step would be to find what in your room is actually rattling, then look at fixing that?
 

Rock Danger

Distinguished Member
I have an ICE passive subwoofer with an Earthquake amp. I talked to my dealer and with dirac these two frequencies can be lowered slightly to avoid the rattling. Looking how I can achieve this on the MP-50. So its the LFE not the two subwoofers.
I dunno what to tell you, but from what you describe there's only 2 things that can make a driver rattle.

It's either structurally unsound or the the amp is clipping causing the speaker to distort. LFE is just a name for lower frequencies on the FR.

If your speaker is distorting it will die sooner or later as it'll burn the coil out.

I'm not familiar with your set up, but to take a general guess you have it turned up to loud. Did you adjust the gain after room perfect? Was the gain up really high when you ran room perfect.

I understand what you want to do, but it's not the way to go about it, I don;t know anyone on here that would recommend that you go into the voicing tool and reduce some of the lower end band - the rule of thumb is turn a big amp down not a wee amp up.

If you insist on this method you need to familiarise yourself with the voicing tool which will let you roll off some lower end stuff but I would say you need to set it up properly.
 

Rock Danger

Distinguished Member
Sounds like the first step would be to find what in your room is actually rattling, then look at fixing that?
He says it's his drive unit, not the room. If it's the room, fix the structure.
 

orange55

Well-known Member
He says it's his drive unit, not the room. If it's the room, fix the structure.
Wow, sounds like a new sub is needed, especially having invested in a MP-50.
 

Rob Sinden

Distinguished Member
AVForums Sponsor
All the info I have about the design, build and end results of my “perfect dem room” can be seen here and anyone is welcome to hear it any time. Building The Perfect Cinema - Gecko Home Cinema

As you can see the room is a good size/ratio, well-constructed used bass traps, side wall diffusion, absorption and adjustable ceiling diffusers. It was designed by a company with excellent credentials who wouldn’t be influenced by adding more treatment……. that they happened to sell.

Most acoustic designs I have seen involve adding a few different types of material to most of the surfaces in the room by companies who sell the products.

These designs remove all reflections at specific frequencies which screw up the overall sound of the speakers used. These “designs” have no method of addressing bass issue which the design of my room did.

I installed a room that is very similar to the types of designs typically being sold in the UK now in my Chelsea showroom in 2000. It ruined the sound of the speakers.

My motivation for saying these rooms are crappy is that last year I calibrated a couple of systems with kit I sell and they didn’t sound great because the rooms were over treated. I calibrated about 20 cinemas last year and the ones in the untreated rooms sound great.

Acoustic simulations look impressive but assuming you have a fixed sized space and speaker/sub locations are fixed, what do they achieve? They will recommend bass traps in the corners that are expensive and will have almost no effect while recommending a combination of diffusion and absorption elsewhere.

If anyone can show a home cinema simulation that leads to a different “solution” than this and that results in measurably better sound, please post it here.
 

arisholm

Well-known Member
Hi Arisholm

If you have run RoomPerfect and there is still a problem, I’m sure you are right.

My experience is mostly in UK rooms built with brick or Celcon blocks covered with Gypsum. If the room has reasonable proportions and some furniture I can almost always get great sound in these spaces.

I’ve installed a number of cinemas in Greece and Spain and the different room construction create very different acoustics. They are usually obviously overly "live" spaces where mid and hf reflections needed absorbing. Once this is done getting great sound typically isn’t a problem.

I’d love to know more about the size/proportions of your room, its construction, the layout of the kit and any carpets, furnishings etc. Would you be happy to post some photos?

I’m would have thought that bass hanging around at 40Hz would only happen in a basement? Is it an obvious audible problem or just something that shows up in measurement?

Do you have any info on the products that you’ll be using to absorb 40Hz?
Hi Rob,

Those who have heard the system can attest to that it already sounds really good. This "urge" is based on measurements and simulations and me nerding out, striving for ultimate perfection... I've helped measuring and optimising a lot of rooms with RP now and mine is not "bad" in any way, actually it has excellent frequency response (posted a graph a while ago), and overall unusually good decay above 40Hz after some ceiling treatments etc.

So basically, the only thing left I see can possibly be improved is the 40Hz (and below) "issue", which is always hard to fix completely in a small room. Dimensions are 4.5m by 6.5 meters by 2.25m, with "soft" construction (wood). Symmetrical side walls and slanted ceilings front and back (which actually is a good thing). Subs are "almost" corner placed. Speakers are placed 3m from the front wall due to a chimney in the middle. This may sound a bit awkward but works surprisingly well both subjectively and in terms of measurements including impulse response.

Both simulations and measurements show that such room dimensions will have main axial modal resonances at 26Hz, 38Hz, 52Hz. And it causes a dip at 40Hz in the only possible listening position, combined with slow decay (also after RP) around that frequency. RP fills in the dip to some extent, but does not fix the decay. Furthermore, simulations show that I can get rid of this with better absorption of the front wall. So I though I would try. Fiberglass porous traps are not effective below 100Hz or so, and even then would require huge amounts of it which will also deaden the room too much. But the traps I have ordered, called RPG Modex Super Edge, are huge resonating chamber high-pass design going all the way down to 20Hz. I don't *know* that this will fix anything but it should...

So this is just an experiment for a true nerd to enjoy in difficult times. We'll see how it goes.. If people are interested I can provide a longer description later on with pics and measurements both treated and untreated, before and after RP. And compared with ARC that I can use in the main speakers (semi-active Paradigm Persona 9H). That is the plan! It will take some time as international transportation seems to be a bit slow these days, for obvious reasons :)

Cheers! Erik
 

Rob Sinden

Distinguished Member
AVForums Sponsor
Hi Erik

Thanks that’s really useful. I too suffer from Nerditis and the never-ending itch for it could be better…..

Is there a particular reverb time you are aiming for at different frequencies?

As the main problem is a dip at 40Hz, I assume you’ve tried placing the speakers much closer to the rear wall and repositioning the subs?

Do you have any details of what in the RPG Modex Super Edge boxes and data on its absorption?
 

StephanG

Active Member
It was designed by a company with excellent credentials who wouldn’t be influenced by adding more treatment……. that they happened to sell.
Thank you for the link. I see you have used Rives, which is a shame. They had a track record for delivering horrible results, which is probably the reason they went out of business a few years ago. There are also plenty of stories how people had to hire other companies to fix the mess that Rives left behind. At least that explains that. But as it is in life, sometimes you win, sometimes you lose. Rives did beautiful looking rooms though, one can't argue about that. What is the noise rating of the room?

Acoustic simulations look impressive but assuming you have a fixed sized space and speaker/sub locations are fixed, what do they achieve?
Have a look at the theater I linked to above designed by Keith Yates. It also shows what it gives you and that is by far more than placing some bass traps in the corner. Maybe give him a call.

Of course, if the whole concept is everything is there, stuff can't be changed and the speakers have to go in this specific spot and you absolutely can not change anything, then the whole concept is flawed from the very beginning and you will never have the best result possible. How would you achieve a homogeneous soundfield for all rows and seats for example. If that's the goal, then that's what it is. For me, that's not a home theater, it might be a living room with some speakers put in places where some space is left or a kitchen with audio.
 
Last edited:

Rob Sinden

Distinguished Member
AVForums Sponsor
Hi Stephan

Thanks that’s really useful. I’ve had a quick scan and can see that their designs are light years away from what it being offered by 99% of home cinema designers/installers in the UK.

My main interest in raising these issues about acoustic design is to highlight that most of the designs being offered in the UK make sound quality worse and not better and that they simply cannot address the biggest problem in most systems, uneven frequency response.

I didn’t know other people had issues with Rives designs. When I researched this 10 years ago, I liked their approach which was for a live room with diffusion rather than absorption, something that it seems K Yates recommend too and more people are wising up to.

I also liked the people at Rives, the number of professional installations they had done and the fact that they weren’t selling product which creates an immediate conflict of interest. I’d be interested if you have any links about other designs they had done that weren’t popular.

I can’t see the links you posted but I’ll have a read of the site one evening.

Cheers

Rob
 

Similar threads

Trending threads

Latest News

LG launches Gram laptops for 2020
  • By Andy Bassett
  • Published
Hisense U8QF TV heads UK 2020 range
  • By Andy Bassett
  • Published
AVForums Podcast: 24th May 2020
  • By Phil Hinton
  • Published
Sky HDR launch rumoured for 27th of May
  • By Andy Bassett
  • Published
Top Bottom