Erwin's House & Homecinema project

[Erwin.BE]

Chrystal Castles at concert level...

Attachments:

[Erwin.BE]

OK, I completely lost my senses and twisted the layout by 90°!

The screen actually divides the room in a HT+diner section and a kitchen corner. So when someone is doing something in the kitchen with lights on, it will be les disruptive for the viewer enjoying a movie in the dark.

The DIY subs behind the screen can be turned around and backfire to the kitchen. This leaves their whole "frontside" free to apply acoustic treatment.

The center can now be the exact same tower as the L+R Front. It's the garganteous DIY DTQWT-12 designed by Troels Gravesen. Left-over space can be filled with fiberglass as broadband absorption.

The L/R Side Surrounds can now be at their ideal 90° off axis position (they were about at 110° before). They're now somewhat closer to MLP, but still at decent distance.

The diner/breakfast table can now be put against the back of the seats. The garden is still in sight when the curtains are open while the screen can also be viewed.

Nothing but good except for the back door to the terrace now being in a less than ideal position. It should have been in the corner. Now it is harder to get to that door and also forces the Back Surrounds a bit wider then I'd like. But I cannot change that since the frame is already in place.

That's five improvements for one drawback. I think I will do it!

BTW, note the three extra Top Surrounds making it 14.4 ;D

Attachments:

[The Mad Norseman]

Wow Erwin!
VERY nice!
Thanks for including the plan too, looks like a large room, about 21.5 feet wide, but rear viewers are only 11.5 feet from that large screen - NICE!
Looks like you have acoustic insulation panels to cover the windows when the HT is in use too(?). If so, a great idea so you can still use the room for other purposes.

I like what you're doing - and if the Mad Norseman is ever in your neck of the woods, he may have to insist upon a movie demo!

Keep the updates coming!

[richardrc]

Hey Erwin, you must have had the house rocking to get those blue lights to move, hope you had hearing protection

[Erwin.BE]

Aug 28, 2012 7:49:30 GMT -5 richardrc said:

Hey Erwin, you must have had the house rocking to get those blue lights to move, hope you had hearing protection

I used the Rothwell inline attenuators on the amp inputs. They dissipate 10 dB so the amp has to work harder. Benefit is that the output volume of the Weiss DAC2 is higher. Less digital attenuation = better resolution, better sound. Though the attenuators themselves allso cause some quality loss.

It was loud, but just not to loud for a short time.
Also dubstep etc will make the leds dance since the low frequencies need lot's of Watts.

[Erwin.BE]

Aug 27, 2012 20:34:21 GMT -5 The Mad Norseman said:

Wow Erwin!
VERY nice!
Thanks for including the plan too, looks like a large room, about 21.5 feet wide, but rear viewers are only 11.5 feet from that large screen - NICE!
Looks like you have acoustic insulation panels to cover the windows when the HT is in use too(?). If so, a great idea so you can still use the room for other purposes.

I like what you're doing - and if the Mad Norseman is ever in your neck of the woods, he may have to insist upon a movie demo!

Keep the updates coming!

The room is L +28 by W +22 by H 8 foot. That's 5,000 cubic feet. THX Ultra is only up to 3,000 cubic feet!

The windows have heavy black curtains. I might add some sort of early reflection absorbers.

Every Emotiva Lounge member would be very welcome...

[The Mad Norseman]

Oops! - got my meters to feet calcs off, but those heavy black curtains should do the trick nicely.
That's also about the volume of my living room that doubles as my HT (and a very genuine thank you to Mrs. Mad Norseman for that!). So I understand the need to bring in more power and higher SPL capable speakers!

[Erwin.BE]

An old rendering from XPR+RMC

Attachments:

[Erwin.BE]

Floorplan with some tweaks here and there. Detailed the seating from Ekornes

Another thing is that I am going to work with an acoustician for proper treatment.

Attachments:

[The Mad Norseman]

VERY nice Erwin!
I'd love to see a section or two also to get a feel for the height, the acoustic ceiling treatments, etc.
Maybe a couple interior elevations?
So its seating for four with (what looks like) another six on stools at a counter behind?, or,...?

[richardrc]

Great to hear that you're getting in professional for acoustic advice.

The room is looking in very detailed, I love those seats from Ekornes, but I do wonder how well the centre ones will work with surround sound.
With my current seating, which is a 3 seater non reclining high back, I know that you loose a lot of the surround effect because your ears are positioned at or below the top of the back and the back is continuous. If you sit on a cushion the surround effects are markedly improved. Giving the rears more gain doesn't fix the problem, as the seat is just wrong. I will just make sure the seats in my future HT aren't to high or continuous across the back. (I still love the look of those seats!!! ;D )

[Erwin.BE]

We need to really test the seating ofcourse. But this guy has them and I cannot imagine he has issues with the headreasts blocking the sound. Check out the speakers he has!

www.hometheatershack.com/forums/home-theater-room-photos-finished-rooms-only/59241-aktos-purple-home-theater.html

Behind the seats is a normal table height with comfy chairs. BTW, I was quoted 7,500 euros for the seating as I designed it, but with normal external armrests vs the functional armrests for all four. Leather was 1,500 extra. If the assembly is done in Norway, those are normal prices. I will get a rebate in due time.

I have an appointment with the acoustician next week, but for now here's a link to his website with great info (in dutch) and pics:
www.soundscapes.nu/d_klaar.htm

As you can see, he works more with diffusion than with absorption. But he measures the empty room before he designs and proposes the treatments.

[Erwin.BE]

Oh, I forgot to mention I received 4 Eminence Deltalite II 2510 woofers to build the first pair of DTQWT speakers. The kit is now complete, since I got the crossovers, tweeters and midrange some time already. These substantial towers are for the Surrounds, identical ones will be made for Wide and Back Surround. The LCR wil need 2512 type. Yes, that's two 12" for each.

Speaker building time!

[The Mad Norseman]

Sept 14, 2012 8:28:58 GMT -5 richardrc said:

The room is looking in very detailed, I love those seats from Ekornes, but I do wonder how well the centre ones will work with surround sound.
With my current seating, which is a 3 seater non reclining high back, I know that you loose a lot of the surround effect because your ears are positioned at or below the top of the back and the back is continuous. If you sit on a cushion the surround effects are markedly improved. Giving the rears more gain doesn't fix the problem, as the seat is just wrong.

A very good observation!
A local friend of mine had this very same problem with his high back HT seating - beautiful and comfortable seating - BUT he couldn't effectively hear the surround/rear channels.
But there are two solutions available:
1) Raise up, and point downwards a bit, your surround speakers (get the speakers directionality (is that a word?) pointing over the tops of the seat backs.
Or,
2) Get different seating.

Since #1 can 'waterfall' into creating other problems throughout the room that then also need addressing and correcting, (sonic, decorative, WAF, or otherwise), I'd recommend #2...

[Erwin.BE]

So I had the first meet and greet with the acoustician past Friday. His name is Toine Dingemans and he is living in The Netherlands near Den Bosch. His flat that he rents is in a passive house construction just like our house build, so we immediately had something to talk about.

Turns out the way most passive houses are constructed is playing an important part in the bass absorption. The supporting structure is a "Canadian" wood frame filled with thermal damping. In this case the walls are 1 foot thick, made from joists that are normally used for supporting floors and 2 feet apart each other. This provides some very good bass absorption. I always guessed it did so, but found little or no actual numbers on that. But Toine confirmed that his flat has good bass properties despite not having any room treatments or bass absorbers. I shall further try to enhance our space's inherent bass absorption by putting Fiberglas in between the supporting joists of the floor above. These joist are 40 cm (16 inch) height. Putting 12 inch of fiberglass in it is as good as filling it 100%.

Room ratios was then discussed. Bad room ratios cause standing waves. A standing wave is a point in the room where a certain bass frequency is exited or canceled out by it's own returning reflection. These are impossible to avoid, but you'd want the lowest problem frequency as high as possible since the very low frequencies are hard to tame. Toine mentioned on his website Soundscapes.nl that Salford University (UK) proved that many good room ratios exist but that they are room size dependent. Ie, a room ratio that might be good for 1000 cubic feet might be bad for 3000 cubic feet. Salford tested three typical room sizes (50/100/200 m3) (multiply by 33 for cu ft) and calculated all "best" room ratios. A spreadsheet can be downloaded here:

www.acoustics.salford.ac.uk/acoustics_info/room_sizing/?content=best

To my great delight, I found our room ratio in the 200 m3 size (though ours is 152 m3 this should be representative) to be among the "best" listed! I reported this to Toine and prior to my arrival he had made a spreadsheet for our 851 x 690 x 260 cm room which is 1 / 2.63 / 3.27. Turns out the lowest problem frequency should be 101 Hz which is a very good result since 100 Hz is comparatively easy to deal with.

After the drywall is completed, he will come over and measure the room reverberance and from this result he will propose the treatments. He works with whatever is in the room. But some choices made earlier determine what kind of treatments are further need. For instance, many HT builders choose a room wide carpet. This is not ideal because it dampens a lot of the high frequencies but does little or nothing to mid frequencies. So when you put broadband absorption against the ceiling you might very well end up with to much high frequency absorption. What you end up with is a dry room without sparkle. That's one of the reasons I chose polyurethane industrial flooring. It's nice to walk on with bare feet but it is reflective. Ofcourse a thick carpet will be put on the floor anyway, but only to deal with the first reflection points from the LCR. I guess it will be like 10*5 feet.

We also talked about room symmetry, which he also mentioned on his website. I am aware the left wall is drywall while the right wall is triple glass. The heavy black curtains I figured would be beneficial for both blocking sunlight and acoustics may not be ideal after all, since this would almost make it necessary to put those same curtains on the left wall... I will look into using screens with total light control. This means that the sides are caught in a guidance (alloy profile). More about that later when I receive a quote on that. This would be more reflective hence be more symmetric to the other wall. Obviously something has to be added to deal with first reflection points. I am prepared to put up with devices that are placed before the glass if they are mobile and don't block the entire view. What these consist of is the object of further study after the measurements. But Toine is a fan of diffusion rather than only absorption.

The ceiling is where most of the treatment will happen. It's a very large surface that's usually not functional other than defining the room boundary. What Toine usually proposes is a diffusion "island" situated between MLP and LR speakers. The best place for diffusion however is the wall behind the LR speaker. In our case these are the very large subs (almost 8 feet high). Since these are set in a freestanding "block" where the back side is facing the kitchen, I would let the subs backfire. This would make the backside of the subs available for treatments. Toine suggests diffusion. The center speaker (same tower as LR) would benefit from some flanking absorption, I would imagine.

The rest of the ceiling would be available for broadband absorption to be determined after the measurement. I could go ahead with my original plan and this is to make 4 inch thick absorbers from Fiberglas in a frame covered with black cloth and hang these 4 inch from the ceiling. It's up to Toine to calculate how many would be needed.

Another good spot for absorption is the back wall. But this is also Glass so that is difficult. Maybe a partial movable solution could be incorporated.

Toine suggests to do a second measurement after this to find out if some problem area's still exist and these could be cured with appropriate devices. Maybe some frequency would benefit from narrow band bass absorption. Impossible to predict at this point. So, something has to be kept behind since adding treatment makes more sense than removing.

[The Mad Norseman]

Very nice, very nice.
I'm also looking into acoustic room treatments, so read Toine's suggestions for you with great interest!
Good that you also include the "whys", and "hows" in your posts - that helps too. The nice thing about the kinds of room treatments being discussed is that they are movable so you can experiment with what kinds of results you're getting, and decide what you like, or don't like, move them, try again, etc.
Very different treatments on opposite facing walls (drywall vs. heavy drapery over windows for example) must be a real challenge as well, trying to keep the sound-stage balanced!

Thanks, and keep the reports coming!

[Deleted]

You should also ask Toine if it is possible to make the ceiling non-parallel with the floor. This should virtually eliminate any floor to ceiling reflection points and will greatly reduce the possibility of standing waves caused by parallel surfaces. You might also be able to do this with the one side wall so that it is non-parallel with the glass wall...

-RW-

[Erwin.BE]

Okay, someone try to talk me out of building these for LCR:

www.tangenavdesign.com/html/inconcert_miles.html

Here's BEF-NO's HT-build thread with the InConcert Miles speakers and matching surrounds.
www.avsforum.com/t/1416004/bef-from-norway-diy-uncompromising-theater

It uses a big Air Motion tweeter like the Emotiva Pro's, but in combination with a horn for extra output and controlled directivity:
www.beyma.de/index.php?id=174&L=1

The only thing against them is that they're not active designs, but they are massively overbuilt so distortion will not come into play. I already have the XPR-5 and I guess the combination will be able to peak at 125 dB @ 1m, which will be 115 dB @ 12 feet (MLP). This is 10 dB more than reference peak level (105 dB). Should be enough....

Attachments:

[oregonbill]

These look awsome. Are these the one you are going to build for sure?

[Erwin.BE]

Apr 2, 2013 16:06:37 GMT -5 oregonbill said:

These look awsome. Are these the one you are going to build for sure?

For sure? Only a fool never changes opinion... But at this point, let's say these are in pole position.

The DTQWT-12 I thought for the past two years to be building cannot take the 400 Watt of the XPR-5. The JA8008 midrange doesn't like that much power. It's a great music transducer but I fear it will not resist the power bursts of an action movie at reference level. Mind you, I do have a kit for a pair of DTQWT-10 lying around since a good year! I will still build it, since it will do fine in my wife's office.

So over the last few months, I browsed the net to search a design that is more suitable for HT.
*The stealth 8 was/is a contender. Not that it's a small speaker, but I'd prefer a bigger one. A d'Appolito MTM with 10" woofers would be more to my taste.
*The Teufel System 10 LCR (S 1000 FCR) came to mind, that gets good reviews and it can take 540 Watt long term.
*I had a look at the JBL pro cinema line. These seem to favour one or two large mid-woofers and a horn tweeter on top. This affordable DIY design is similar, but with the horn built in the baffle: www.diysoundgroup.com/waveguide-speaker-kits/fusion15-kit.html

If my funds were limitless, I'd just buy the B&W CT8 LR and be done with it.
www.bowers-wilkins.eu/Speakers/Custom_Installation/CT_Series/CT8-LR.html

So I like big speakers for LCR. The inConcert Miles will never leave me thinking: what if I went bigger... And that Air Motion tweeter pretty much seals the deal... It comes with the horn as standard.

Here's the translation of the instructions:

Inner damping:

It should be attenuated by 5 cm rockwool on the bottom plate and the back plate. The whole room behind the treble filled with Rockwool. The sides should be moderated by 5-7 cm foam.

The internal stiffeners of the cabinet must be punched out in the middle to secure passage of air through the chassis.

Technical information:
Frequency response: 30 Hz - 25 kHz
Sensitivity: 103 dB for about 2.83 V
Impedance: 4 ohm
Recommended amplifier power: 1W or more.
Power tolerance: 1600W continuous pink noise (ref AES2-1984 standard)
Treble element: Beymen TPL-150H
Bass / midrange: Beymen 15P80Nd (2 pcs)
Crossover Frequency: 900 Hz
Recommended listening distance: 2 meters or more.
Dimensions: 46x56x110 cm (WxDxH), weight approx. 60 kg

Note the very low crossover point of 900 Hz. And since it goes down to 30 Hz, some experimentation with a lower than 80 Hz crossover to the subs will be possible.