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sen8or
974 posts

Ultimate Geek


  #2512570 26-Jun-2020 08:16
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What tipped me from JVC to Sony was at the time, Sony were running a free lamp promo, so the projector cost around $7800 on special pricing at AV world plus a free lamp.


LostBoyNZ

373 posts

Ultimate Geek


  #2512571 26-Jun-2020 08:22
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sen8or:

 

My projector is the 270 and I too compared it against the N5 JVC when I bought it (also from AV world, I was in Auckland last christmas so was able to see them both in person at their demo room),

 

When fed quality 4k content, either is stunning. I felt the Sony had a bit more pop and the fine detail it can render is great. I have mine hooked up to xbox x for streaming from netflix, hulu, HBO. Unfortunately there is only a limited amount of 4k on them, so most of what we watch is upscaled 1080p, but it still looks great.

 

What part of Christchurch are you building in?

 

 

Thanks, that's great to hear too :) Out of interest do you use it in a completely dark room?

 

We're building in Woodend, which is about 10 to 15 minutes north of Christchurch. Compared to buying in Christchurch, we just got much more space in our section for the same price, and we don't really mind the drive (most days, haha!).

 

We've basically having two bedrooms next to each other but aren't putting in a wall, and just one door. The idea is that'll be our home cinema but in the future when we sell, if the new owner really wants a 4 bedroom house instead, they can put up a wall and add an extra door.


 
 
 
 


AceVPD
137 posts

Master Geek


  #2512583 26-Jun-2020 08:41
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"Thanks, yeah I've been reading up on those and it does sound like the way to go. It looks like GreenStuf® AAB Autex Acoustic Blanket 20-100 Black would do a great job, how do you find the 50mm Rockwool?"

 

Hey. I haven't brought any yet but from my research came to the conclusion that this is what I should use.  Ideally with a 50mm air gap behind the rockwool. So I was thinking 100mm timber frame with the 50mm rockwool at the front with acoustic fabric or speaker cloth.

 

From my notes the Fibretex 350 is 60kg/m3 density which is closest to best for reflections.  Internationally Owen Corning 703 is often recommended but I could find that locally. 703 is 50kg/m3 so pretty close.

 

50mm or 75mm Fibretex 350 Industrial Rockwool from https://potters.co.nz/

 

I have a similar size room as you. 3.4m wide. The entrance door is in the front corner on the side wall where I would want my speakers.  I have then a meter or so forward of the screen.  They are +/-30 degrees from my listening position which I believe is in the right range. From memory its +/-22.5 to +/-30 (45 to 60).

 

I brought a cheapish (~$200) 135" 16:9 motorized screen for trialing.  It is about 3m wide. My theater (work in progress) is in our under house garage and the ceiling is only ~2m.  Not ideal. So I can't get full height with the screen. Viewing distance I am ~3.6m from the screen. I think this is ~ 2.8x the image height for scope.

 

I have set up my projector (Optoma UHD51 from AV World) so scope/2.4:1 movies are full width.  For 2.1 (Netflex etc) and 16:9 I zoom it down. For viewing distance I like closer to constant height image rather than constant width (Like a TV, less image area for scope).  

 

For Dolby Vision on a projector (or non DV TV) have a look at this.  I have one. Made quite an improvement for HDR on my projector. Especially from Apple TV 4k. 

 

https://www.hdfury.com/enjoy-dynamic-dv-content-from-lldv-source-on-any-hdr10-display/

 


sen8or
974 posts

Ultimate Geek


  #2512617 26-Jun-2020 09:24
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No, my room is not completely dark. I have two walls that are painted in Resene's "black rock", and the rear wall is fully curtained in a dark curtain, but ceiling and one wall in standard colour (resene Sea Fog). I had that colour when I was in Auckland and it wasn't as dark as I remembered, a lot bluer in light, but when the lights go out, its plenty dark enough.

 

Its a bit of a compromise as my wife didn't want a black cave, but in truth, I still absolutely love the whole cinema

 

Click to see full size

 

Click to see full size

 

Click to see full size

 

Click to see full size

 

 

 

The screen is 106 inch wide, the room is 4.4m long x 4.0m wide and the couch is now around 70cm from the back wall, so viewing distance is around 3 - 3.5m to the screen.

 

I was struggling to decide between 106 and 120 for screen size, in the end went slightly smaller (my wifes preference) and I'm pleased I did. With how I have the front set up, I think 120 would have been too tall for 16:9 and 2.35 viewing is really comfortable, immersive enough but you don't have to move head side to side to follow the on screen action.

 

 


allanf714
16 posts

Geek


  #2513583 27-Jun-2020 11:38
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AceVPD: Curtains look good and will help absorb reflected light for better projector contrast but may not be as good for as some diy sound absorbtion panels for sound. I have yet to build mine but plan on using 50mm rockwool 50mm out from the wall at the first reflection points.
I have a similar size room.

 

 

 

I would second this opinion of using "panels" for acoustic treatment.  The primary goal in treating a room for home theater purposes is to eliminate the 1st order reflection points.  You can establish these points with a mirror, a helper, and a pad of stickies.  Treat these areas first (including the ceiling).  Don't forget to build bass traps for the corners 2nd.  Then add additional panels to taste (whether you want to room to sound more "dead" or "alive".  I have historically used OC703 when I was in the US.  But, I have referenced the absorption coefficients on rockwool... and it works very well!

 

I wasn't clear if you are using any equalization.  If nothing else, take the time to equalize your subwoofer system.  Makes a big difference in the perceived quality of the bass effects.  

 

 

 

Cheers,

 

Allan 


LostBoyNZ

373 posts

Ultimate Geek


  #2513584 27-Jun-2020 11:42
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100mm timber frame with the 50mm rockwool at the front with acoustic fabric or speaker cloth sounds like a great idea yeah. Thanks for the source with Potters too, I've noted that down :)

 

I think this will be where I'll put the seating and screen in the room:

 

 

So the 'front' row is the same distance as yours roughly. 3.5m from the screen, which is a 45 degree viewing angle with a 130" screen. Then there's a 60cm gap between the front and back seats. It'll all vary a bit when I get exact measurements of the seats etc, but just for a rough idea. I wish the room had been like 20cm wider now, but it's too late in the game to change that.

 

The HD Fury link about LLDV output is interesting too. I use Kodi on a PC at the moment, but plan to move to having content on a 'server' (just a PC elsewhere in the house) and Kodi on a small machine in the hone cinema. The link mentions Shield Pro is supported, and if I remember right Kodi can run on the Shield Pro so that sounds hopeful.

 

Thanks sen8or for the pictures too!

 

We're planning on using Dulux Titirangi ( https://www.dulux.co.nz/colour/all-colours#!/colour/duluxnz_duluxnz_28377 ) for the walls, ceiling and door. This is it on the left vs Ressene 'black rock' on the right: The 'black rock' is a bit less reflective, but hopefully this works well too.

 

That's great to hear you were pleased with the screen size too. I'm going to have to shrink our screen I think, for the sake of the speakers. I'm not sure if either I should sell the 130" Studiotek 130 16:9 Fixed Screen, and buy a smaller screen, or put black surrounds over part of this screen. I guess by putting black surrounds over part of it, it's not a permanent modification should I ever want to sell it, and it's probably the cheapest option.


LostBoyNZ

373 posts

Ultimate Geek


  #2513586 27-Jun-2020 11:51
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allanf714:

 

AceVPD: Curtains look good and will help absorb reflected light for better projector contrast but may not be as good for as some diy sound absorbtion panels for sound. I have yet to build mine but plan on using 50mm rockwool 50mm out from the wall at the first reflection points.
I have a similar size room.

 

 

 

I would second this opinion of using "panels" for acoustic treatment.  The primary goal in treating a room for home theater purposes is to eliminate the 1st order reflection points.  You can establish these points with a mirror, a helper, and a pad of stickies.  Treat these areas first (including the ceiling).  Don't forget to build bass traps for the corners 2nd.  Then add additional panels to taste (whether you want to room to sound more "dead" or "alive".  I have historically used OC703 when I was in the US.  But, I have referenced the absorption coefficients on rockwool... and it works very well!

 

I wasn't clear if you are using any equalization.  If nothing else, take the time to equalize your subwoofer system.  Makes a big difference in the perceived quality of the bass effects.  

 

 

 

Cheers,

 

Allan 

 

 

Thanks Allan. Agreed that sounds like a great idea. The YouTube channel Home Theater Gurus seems to be a great source of information too, I was just watching an episode about reflections and the mirror trick before too. I haven't looked up about bass traps yet but I just did a quick google now and that seems like something we can easily do yes.

 

At the moment I've got a Pioneer VSX-LX70 receiver that goes between the PC and speakers / TV. I remember there's a microphone option that I used for setting up the equalization, but I'll update the receiver too with something that can handle 4K, HDR and Dolby Atmos. Do you think the auto equalization is usually pretty good? Or is it worth adjusting it manually?


 
 
 
 


Dunnersfella
3868 posts

Uber Geek


  #2513596 27-Jun-2020 12:19
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sen8or - can you please move your centre speaker so it's aligned dead central... it's triggering me!

 

 

 

Also, bring your centre further forward so the front of it is sitting at the edge of your cabinet. This will help avoid the first standing wave caused by your entertainment unit and will sound better for it.


AceVPD
137 posts

Master Geek


  #2513610 27-Jun-2020 13:00
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Home Theater Gurus is a good source of info. Steven Smith is also quite active in some of the Home Theater FB Groups.
If you really want some deep knowledge Home Theater Geeks on YouTube is a good source of info although they havent made any for a while. The editor of AVS Forums did them. They had a lot of industry experts on there.

allanf714
16 posts

Geek


  #2513729 27-Jun-2020 17:46
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LostBoyNZ,

 

I wanted to comment on a couple of other things. 

 

 

 

Don't forget about Audioholics with regards to useful videos.  I am not as familiar with Home Theater Gurus.  But, Audioholics made some older videos that were great for those new to the hobby.  Although, as the name would imply, more focused on the audio side of home theater. 

 

Re: building bass traps. 

 

The best design for bass traps is somewhat debatable.  Two media rooms ago I hired Richard Rives (of Rives audio) to consult on a media room design.  I think he has closed shop at this point.  But, he was a prominent acoustician in the field @ that time.  He had recommended that I build bass traps using a diaphragm @ the front made of a particular thickness of pond liner.  Both he and Floyd Tool indicated that the most effective bass traps are built this way b/c the most effective way to attenuate low frequencies energy is to force those LF pressure ways to do work.  So, they would vary the size and thickness of the diaphragm according to the what they were attempting to attenuate.  His plan called for custom soffits all the way around the room where the ceiling and walls meet... in addition to the corners.  That was waay more effort than I was willing to put into bass traps.. so I ended up buying various bass traps from GIK.  As a matter of fact I have

 

https://www.gikacoustics.com/product/gik-acoustics-soffit-bass-trap/

 

https://www.gikacoustics.com/product/gik-acoustics-tri-trap/

 

https://www.gikacoustics.com/product/gik-acoustics-244-bass-trap-flexrange-technology/

 

all of these types of bass traps in my garage right now.  Now, with that said I believe the GIK bass traps are nothing more than a bunch of rockwool stuffed into various sized.. simple frames.  GIK offers a hard membrane on the front of the bass trap.  This is not done, in their case, to improve absorption of LF enerty.. but rather to ensure that that the traps are not full range.  In other words, they absorb LF and reflect HF energy.  Remember before I mentioned that an overly absorptive room is not ideal?  It's a balance.  And that is why diffusion, mixed (absorption/diffusion) products exist as well.  With all of that said.  For reasonably easy and cost effective HT solution... focus on absorption @ your 1st order reflection points, corner bass traps, and then add additional wall panels until you get a nice sound (not too dead, not too reverberant).  Keep you panel thickness to 2" minimum for wide bandwith panels.  Although my preference is 2" of material with 1.5" of air behind it (like GIK242 panels).  for the bass traps, just build a rectangular or triangular frame.  A thin frame is fine unless you intend it to be load bearing.  Fill it with wool and cover it with a nice material.  It may not be the most effective design... but it will do the trick. 

 

 

 

On your screen size.  The traditional mode of thought is 2.5x the horizontal width of your screen.  So, sitting 12' away... your magic number is a 110".  That is the way I ran for a LOT of years.  But, in my last media room (before I moved to NZ, we switched to a 120" screen.  Both my wife and I liked it better.  Neither of us felt that it was too big.  130... is probably pushing it :).  But, I am definitely an audio guy, with both my education and experience tilted in that direction. 

 

 

 

Your AV receiver does have room calibration... and you should definitely use it.  Pioneer's particular version of room calibration is called MCAC.  This process will set up your channel levels for you, set up delays properly (so that each channel is in phase), and apply some amount of equalization to each channel such that each channels response @ the listening position is relatively flat.  More complicated systems will even average over more than one listening position so that things sound right from more than one listening position.  This has both positives and negatives associated with it.  Assuming that everything is hooked up properly and your transducers are in the correct locations these room EQ systems will generally have a positive effect on the overall sound quality.  So, you should do it.  I had mentioned manually EQing your subwoofer system in particular b/c of the picture above with the pair of 13" SV subs above.  I just realized that this picture was was not yours :)  Sorry, I'm an idiot sometimes.  It was more intended for sen8or.  The problem with any of the automatic EQ systems on the market is that they have to design the algorithm for the masses.  In that case they are going to limit the amount of boost that they can apply to flatten the response in the room.  They have to do this because even a 3dB boost requires double the power to achieve.  A 6dB boost requires 4x the power, etc.  So, unless they limit the amount of boost that they apply, the amplifiers in most HT systems (especially the LF region) would run out of steam and distort.  Now, if you have an appropriately stout subwoofer system.. your output is not as limited and you can probably push things a little harder in order to extend the LF response of the system farther than the auto EQ will on it's own.  That is where a manual EQ (dropped in between your receiver and your subwoofer) really shines.  Only then are you able to really hear what those subs can do.  A well tuned subwoofer system is glorious!

 

Cheers,

 

Allan

 

 


LostBoyNZ

373 posts

Ultimate Geek


  #2514154 28-Jun-2020 21:19
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Wow Home Theater Geeks have 373 videos, it does look like an amazing source of knowledge though. AVS Forums good point, I'm a member there also but haven't posted too much yet, mostly just read lots and lots of posts :D

 

Audioholics look great too, I've bookmarked them and I can see many videos there already I'm keen to check out.

 

The GIK products look interesting, was the shipping quite expensive?

 

Or if I go the DIY route, which is probably more likely to keep the cost down, for the bass traps I'll probably go for a triangle shaped one, and just a thin frame (it won't be load bearing). Happy to make my own frames and have air behind the thick material.

 

It sounds like I can probably stick with the 130" screen but use black fabric over it to reduce it down in size. I'll have to calculate the target size with room for the speakers in mind.

 

It sounds like front speakers such as the Kilpsch RF-7 II are meant to be quite far away from the wall, which won't be an option in my room. They'll certainly be limitations in this, but hopefully it's still really enjoyable for a first home cinema.

 

Thanks for all the advice there, and with the EQ too. It sounds like I'm safe to start with the auto calibration which is good, and then when I get to look into a manual EQ it sounds like that'll really help my dual subwoofer setup, nice!


AceVPD
137 posts

Master Geek


  #2514421 29-Jun-2020 14:06
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Thanks for the info Allan!
I also follow Audioholics.

What are your thoughts on Rockwool vs looser fiberglass batts for bass traps? I think I read that Rockwool may be too dense for bass waves so less effective.

Also do you think they are required if you have multiple subs placed correctly. Eg. 2 eq'ed subs at opposite mid points on the walls etc as per the Harman bass experiments. I think it was a Floyd Tool video that I heard that he said you could do that or bass traps but that was better. I might be wrong.

Wondering if I should plan to do both.

Thanks

allanf714
16 posts

Geek


  #2514532 29-Jun-2020 15:50
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LostBoyNZ:

 

Wow Home Theater Geeks have 373 videos, it does look like an amazing source of knowledge though. AVS Forums good point, I'm a member there also but haven't posted too much yet, mostly just read lots and lots of posts :D

 

Audioholics look great too, I've bookmarked them and I can see many videos there already I'm keen to check out.

 

The GIK products look interesting, was the shipping quite expensive?

 

Or if I go the DIY route, which is probably more likely to keep the cost down, for the bass traps I'll probably go for a triangle shaped one, and just a thin frame (it won't be load bearing). Happy to make my own frames and have air behind the thick material.

 

It sounds like I can probably stick with the 130" screen but use black fabric over it to reduce it down in size. I'll have to calculate the target size with room for the speakers in mind.

 

It sounds like front speakers such as the Kilpsch RF-7 II are meant to be quite far away from the wall, which won't be an option in my room. They'll certainly be limitations in this, but hopefully it's still really enjoyable for a first home cinema.

 

Thanks for all the advice there, and with the EQ too. It sounds like I'm safe to start with the auto calibration which is good, and then when I get to look into a manual EQ it sounds like that'll really help my dual subwoofer setup, nice!

 

 

 

 

Long, long time reader of AVS forum.  Lots of very good advice there. 

 

The GIK products:  I shipped them over with my stuff from the US.  well, to be honest I was able to convince the significant other to bring half of my panels.  Panels are large.  My guess is that shipping will be prohibitivly expensive.  This hobby is very frustrating in NZ as we have access to so few things :(.  But, absorption panels are very easy to build.  I think your most difficult challenge will be finding a material that you like.  But, if you have to order material online.. it's not going to cost you an arm and a leg.  Remember to choose something that is more of an open weave.  The material should be acoustically transparent to ensure that the panels work correctly. 

 

On the screen:  I guess you could do that with black velvet.  Do you like the screen material that you have?  If you are using a fixed screen...this is something that is also relatively easy to DIY... and that's probably our best option here in NZ.  Purchase a nice screen material online.  The shipping would be reasonable without a frame.  Build a wood frame.  finish off the edges with a router.  Cover it with black velvet.  Then staple the screen material to the backside.  Hang on the wall. 

 

Here is another thought.  Build a screen wall.  The speakers, in the case of a screen wall, are behind the wall (either flanking the screen or directly behind it.  A screen wall is also relatively easy to make and it's not permanent.  I think that you need 4 2"x4" pieces of wood, the screen material, and fabric to cover the non-screen areas.  This gives you the option to use regular screen material (110-120") and flank the screen with your speakers.  The speakers in this case are hidden behind the material to the left and right of the screen.  Given that you are going smaller, you can use the screen material that you already have for this.  Or, you can order in an acoustically transparent screen material and place the speakers directly behind the screen itself.   This gives you the flexibility to move those speakers off the front wall where they will sound the best.  Bonus on the WAF, the speakers are not visible :)

 

On the speakers themselves.  You are right, most ported speakers (especially rear ported speakers) are not intended to be moved away from the wall.  It really depends on how it was designed... as proximity to the wall definitely effects the LF response in the room... and can be accounted for in the crossover.  So it is possible to have a front or side ported speaker that was intended to be placed right up against the wall.  But, generally speaking, sealed designs are just less difficult if you must place them directly against a wall.  I wasn't clear on whether you already owned those klipsch speakers?  I know that we're thinking out of the box here.  But, consider this.  Three of these up front behind a screen wall. 

 

https://www.diysoundgroup.com/home-theater-speaker-kits/home-theater-series/home-theater-other/88-special.html

 

They are designed specifically for that purpose.  Shallow, front ported and designed to go close to the wall.  I'm not sure if he will ship to NZ.. but, I wouldn't be surprised.  I'm a big fan of the SEOS designs for HT purposes.  I realize that you may be hesitant to build your own speakers.  But, with these pre-designed kits it's really very simple... and fun.  The most difficult part is making them look nice.  Then again, behind a screen wall there is not point in focusing on looks as they will not be visible. 

 

 

 

Cheers,

 

Allan

 

 


allanf714
16 posts

Geek


#2514630 29-Jun-2020 16:36
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AceVPD: Thanks for the info Allan!
I also follow Audioholics.

What are your thoughts on Rockwool vs looser fiberglass batts for bass traps? I think I read that Rockwool may be too dense for bass waves so less effective.

Also do you think they are required if you have multiple subs placed correctly. Eg. 2 eq'ed subs at opposite mid points on the walls etc as per the Harman bass experiments. I think it was a Floyd Tool video that I heard that he said you could do that or bass traps but that was better. I might be wrong.

Wondering if I should plan to do both.

Thanks

 

 

 

Rockwool vs Fiberglass:  To tell you the truth, I'm not really sure.  I do recall Thilo (the lead engineer behind TC Sounds) recommending that I use fiberglass atick/wall insulation inside of a sealed sub as it was more effective than anything else.  Along those lines, I would speculate that the fiberglass has better attenuation in the LF region.... it's available and it's cheap.  My concern there is safety.  I guess you could fill the trap outside and close it up before bringing it inside.  Is an acoustically transparent material a tight enough weave to keep the fiberglass shards from leaking into the room??  Hmmm

 

 

 

On the bass traps.  I have not referenced the Harman bass experiments.  But, I did read Floyd Tool's book on room acoustics... Then again, it's been a number of years and my memory is not too good nowadays.  So, I may very well be wrong as well.  With that said, I thought that the ideal location was about 1/3 the length of the wall?  Either way, I will point out to you that very few of us can realistically place our subs in ideal locations or place our seating position in ideal locations.  So, generally speaking, bass traps are a big help in terms of minimizing nodes and anti-nodes in the room.... and the corners are generally the most productive locations.  Treat the room well and we need less EQ.  The less EQ the better.  Now, realistically, we use treatments where we can or up to the point that our significant others will allow us to 😏.  Then we apply some EQ to get the room as optimized as possible.   

 

Cheers,

 

Allan

 

 

 

 


AceVPD
137 posts

Master Geek


  #2514871 30-Jun-2020 07:03
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Thanks Allan

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