Jean Sibelius
Grip
- Joined
- Dec 11, 2011
- Messages
- 19
- Real Name
- Jan
Hi all,
My name is Jan and I live in the Netherlands. I'm a music lover and hometheater fanatic for more than 25 years.
Approximately 3 years ago I started building my own movie-theater in my backyard.
I hope to finish this project within the next few months (my goal is to be able to watch a movie before the summer of 2012).
As this is my first posting here on this forum I need some time to get familiar with all the options.
Last status
Still some work to do
The starting point
My starting point for this dedicated listening room / Home Theater is optimizing the audiophile properties of this room with a minimum of concessions regarding this aspect (thus in principle go always for the full 100% unless there are very good reasons (e.g. money / effort) to deviate from this starting point.
The main reason is that in my current situation the ratio between music listening versus watching movies is 90:10. This doesn’t mean that I will cut down the budget on audio-visual means such as a projector and a projection screen, but taking into account all the expenses in relation to this listening room such expenses will shift and can be shifted to a later time-slot (this is also beneficial for me as the current projector market has gone nuts, also here in Europe). While making the planning for this listening room all the aspects of such a listening room (e.g. music listening / movie watching / looks / comfort / …) will be taken into account parallel already from the start of this project (so first fully consider everything from A until Z including all the consequences relating to it and only after that really start with the execution of A).
The final ‘looks’ of this Home Theater are of course also important, but come for me on a second place. When I have to make a decision relating to the acoustical properties of this listening room versus the looks of it, the first property will in almost all cases be decisive. At the end the light is off when I watch a movie and when I listen to music I use my ears and not my eyes. This doesn’t give me however a wildcard to create a very freaky room.
Forces from outside (i.e. my girlfriend) will compel me also to take into account the looks of this Home Theater. She wants for instance luxurious chairs in or a big couch on which she can lie instead of e.g. the well known small red cinema chairs (otherwise she refuses to join me while watching a movie). So here the first concessions need already to be made, although these aspects aren’t on beforehand in contradiction with each other (but you have to consider everything into detail). The colors that I will use are also a compromise, e.g. black is too black and red is too common (but as you can see on the pictures, also here we came to a good solution/compromise).
In summary: this listening room strives for a maximum of audiophile properties for both music listening as watching movies, the visual equipment in the room shall also be optimized and the esthetic aspects will be taken into account, but will never be decisive if this has negative consequences for the audiophile properties of the room.
The name for this listening room is also decided: ‘Confidence Mansion’. My ultimate goal is to build up a complete Home Theater setup using Dynaudio speakers from the Confidence-series. Meaning: Dynaudio Confidence C4’s as front speakers in combination with a Dynaudio Confidence Center and Dynaudio Confidence C1’s as rear speakers (maybe including an extra pair of the latter speakers, if I decide to go for a 7.1 set-up or maybe even a 7.2 set-up). In my current set-up I use a Velodyne DD-18 subwoofer.
During the design phase of this project I will frequently ask for input from people here on this forum, so any tips and / or advices are more than welcome. Hopefully my pursuit for the max will motivate other people to do the same. If you have any questions for me, please don’t hesitate to contact me directly or via a private message.
Best regards,
Jan (a.k.a. ‘Jean Sibelius’)
The Netherlands
The basis: Acoustics
Being familiar with the phenomenon: ‘listening room with problem frequencies’, this project started by making the decision to build a complete new listening room with a minimum and preferably no problem frequencies. My girlfriend encouraged me to do so, as in my current situation our living room is for a big part dominated by the Home Theater set-up. This means however check what is allowed by the local authorities, start with acoustic simulations, go to the blackboard and start building after that your complete garden (including trees and previous buildings) is empty. After discussions with the local authorities that it became clear what the maximum surface and height of the building may be, simulations started. In my situation a maximum surface of 810 square feet and a maximum height of 14.8 feet were allowed. After knowing these values an iterative process started to find the most ideal ratios for the listening room while also taking into account other wishes and requirements. As a consequence of creating so much space in my backyard and creating an opportunity to completely redecorate the garden also my former garage and shed needed to be demolished and therefore also a part of the 810 square feet should therefore also be suitable as a new shed. It was however also decided not to rebuild the garage, so I sold my Pontiac Fiero GT from 1988 (which I owned for almost 12 years).
Within the maximum boundaries available for this listening room length x width x height being (26.3 x 21.3 x 10.5 feet) it appeared that internal dimensions of 24.38 x 19.23 x 9.09 feet would be ideal (meaning approximately 4240 cubic feet effective listening room). The outside dimensions of the complete new building became 35.4 x 21.4 x 14.8 feet (meaning 9360 cubic feet capacity).
Based on these dimensions I contacted an architect to formalize the plans into actual drawings which still needed to be accepted by the local authorities (which succeeded after one iteration). Already in this stage of the project it was necessary to take into account the final finishing of the listening room. It was e.g. decided that the walls would be plastered and therefore the internal dimensions between the walls of the structural work were increased to allow a certain thickness of the plasterwork. Also at this point it was decided that a wooden floor would become the finishing touch on the ground and therefore the internal ceiling height was increased by the thickness of the wooden floor.
In this case it was decided to use a wooden floor and not for instance laminate or carpet, because the laminate would probably result in a very frequency specific damping and the carpet would probably result in an over damped listening room (in both situations it is easier to add specific damping than to remove specific damping).
To control the broadband reverberation time in the listening room a total of 7 bass traps are designed and build, each with their own specific volume and effective frequency. The frequencies of these bass traps are tuned at 46, 50, 63, 71.5, 80, 100 and 122 Hertz. After completing the building of these bass traps an actual RT-60 measurement was done, to verify and to confirm that the simulations appeared to be correct. Damping in the listening room above these frequencies is mainly realized by a plastered ceiling that is placed approximately 7.9 inch below the concrete ceiling and which is furthermore filled with acoustic damping material.
It is furthermore realized and taken into account that symmetry is very important in a listening room. The only asymmetry is caused by the inevitable entrance door, but this asymmetry is solved by applying sliding diffusion panels. These panels are slidable for the entrance door when listening to music or watching a movie. Furthermore diffusion panels will be added on all first reflection points of the front and rear speakers on all the walls (front wall, side walls and back wall) and also on the ceiling. On the sidewalls near the front speakers RPG diffractals will be placed as these have a superior frequency behavior compared with the other diffusion panels. It should be noted that the in total 61 diffusion panels and 16 RPG diffractals also have a damping effect that also should be taken into account.
In the overview below, I wrote down some elementary considerations and decisions that were made while designing and building ‘Confidence Mansion’.
Mechanical aspects of the building
What applies for audio equipment and e.g. audio racks also holds for the building itself. Direct and indirect vibrations that are caused by driving the speakers and subwoofers are preferably not transferred via the floor, walls and ceiling to the other parts of the building and parts inside the listening room that could start resonating. To minimize the excitation of such kind of resonances, special counter measures are applied as discussed below.
First of all, the floor in the listening room on which the speakers and subwoofer will be placed is substantially dynamically decoupled from the rest of the building. The floor is a directly, by cast concrete, formed free floating plate with a thickness of approximately 7.9 inch and an estimated weight of around 44000 pounds, being spring supported by a thick layer of polystyrene foam that is supported on the fixed world, preventing the vibrations that occur in the floor reach the rest of the building.
Furthermore all inner and outer walls in the building are formed by thick and heavy bricks with in between a large cavity that is partly filled with insulating material, forming a total wall thickness of 12.6 inch whereby there is no direct mechanical connection between the inner wall and the outer wall.
Finally the ceiling of the listening room comprises 4 prefabricated floor parts, which are mutually connected with iron reinforcement material and flooded with cast concrete, consequently forming one massive and very heavy plate. The total thickness of this plate is approximately 8.7 inch and has a total weight of around 48500 pounds.
All these measures serve the purpose to prevent that the listening room or parts located inside the listening room start to resonate due to vibrations originating from the vibration sources inside the room. A second aspect of this mechanical construction is that it also forms an mechanical filter for vibrations that originate from outside the listening room (both vibrations via the ground, but also via acoustical excitation). A similar construction, but than in a more extreme embodiment, is present in a special reverberation room at the Philips (NatLab) physical laboratories (located in Waalre, the Netherlands) that is fully acoustically isolated and in which very accurate sound power measurements can be performed. Finally the entrance of the listening room is provided with a special selected door, including special glass to make it as sound proof as possible.
Power supply
At the start of this project some modifications were made to my original current supply to enable the usage of the already available, but not connected, 3 phase power supply being present between the street and the distribution cabinet in my house (meaning e.g. a new power meter, two additional and extra heavy fuses, et cetera). After rebuilding the complete distribution cabinet in my house, the ‘new’ 3 phase power supply was extended to the separate building in my garden to end up in a second (‘3-phase’) distribution cabinet located in the shed. At that location it is measured which of the three phases shows the least distortion and that phase is further extended to the dedicated room and only used for the power supply of the several (in total eight) audio groups. The remaining two phases are used for e.g. lighting and the other power consumers in the building. The second phase is, as a rule of thumb, mainly used for my home and all lighting in the separate building (including that in the dedicated room) and the various wall sockets and the third phase is used for the (potential) big power consumers such as the dedicated air circulation plant, the central heating boiler and optionally an air conditioner.
Choice of the electric power cables
Between the distribution cabinet in my home and the distribution cabinet in the separate building use is made of a 5 x 0.056 square inch (~6mm2) Draka Vulta Mb power cable which is unshielded. Between the distribution cabinet in the shed of the separate building and the distribution cabinet in the dedicated room use is made of 3 x 0.056 square inch Draka Vulta Mb. From the latter distribution cabinet 3 x 0.056 square inch Draka Vulta Mb is used to supply the CEE wall sockets and 3 x 0.025 square inch to supply the HMS wall sockets. The CEE and HMS wall sockets can be used to provide power to my audio equipment. The reason why unshielded power cable is used relates to the presence of undesired capacitive effects of such a shielding. Furthermore it is assumed that power cables are mainly the course of crosstalk, so there where no signal carriers are in the neighborhood, it seems not to be meaningful to use shielded power cables. Taking into account that the whole power supply of the dedicated room is set-up spacious both with respect to volume as power capacity it is possible to locate all power supplying cables far from each other to realize space for all the signal carriers. Furthermore the whole power supply in the dedicated room, is as good as possible, shielded by using a so-called ‘Cage of Faraday’ that is connected to a separate earth contact. At those locations where it becomes impossible to separate power supplying cables and signal carriers (from a practical point of view ‘after’ the wall sockets) well shielded power cables are used to prevent possible crosstalk problems. Incorporating this whole layout of the power supply at the start of this project enabled the realization of this principle idea.
Separate earth contact
For the earth contact use is made of massive copper rods which are mutually connected to a total length of 30 feet. This earth contact is mounted into the ground directly nearby the power cabinet in the dedicated room.
Separate audio groups
In this dedicated room there are in total 8 separate audio groups available:
Group 1. Amplifiers (left) (maximum 4 pieces) using CEE-form;
Group 2. Amplifiers (right) (maximum 4 pieces) using CEE-form;
Group 3. Amplifiers (left) (maximum 4 pieces) using HMS wall sockets;
Group 4. Amplifiers (right) (maximum 4 pieces) using HMS wall sockets;
Group 5. Subwoofers (maximum 2 pieces) using HMS wall sockets;
Group 6. Analogue sources using HMS wall sockets;
Group 7. Digital sources using HMS wall sockets;
Group 8. Projector using a HMS wall socket.
Fuse boxes and fuses
All eight above mentioned audio groups comprise a ‘HMS Klangmodule 3i’ fuse box including a specially designed so-called ‘flat wire fuse’. Although in the current design of the dedicated room it is always relatively easy to approach these fuse boxes, but maintenance of the fuse boxes is undesired (i.e. ‘polishing the fuses’), it was decided to chose for HMS fuse boxes instead of alternative Siemens fuse boxes, although the latter fuse boxes are approximately 50% cheaper.
Wall sockets
The CEE-form wall sockets are wired with 3 x 0.056 square inch (~ 3x6mm2) Draka Vulta MB meaning that these CEE-form audio groups are fully wired with 0.056 square inch electric wires. The HMS wall sockets (type ‘gold-plated’) are electrically wired with 3 x 0.025 square inch (~3x4mm2) simply because there are no audiophile wall sockets (at least as far as I know) suitable for larger diameters of electrical wiring.
Comfort in this dedicated room
An important aspect that by the design and building of a dedicated audiophile/home theater (in my opinion) is often forgotten/neglected is the comfort in the room (i.e. temperature control and sufficient ventilation). My starting point while realizing this dedicated room was to search and find a good solution enabling me to control the temperature in the room (both cooling and heating) but also to provide enough ventilation (and that for all weather conditions in the Netherlands) without making any compromise with respect to the acoustic properties of the room.
A first and straight away choice seems to be to incorporate a complete climate control installation, including amongst others an inner and outer unit to keep the noise levels within specific boundaries. A first drawback of such a system is (according to me) the high installation cost but also the high variable costs due to the relatively high power consumption of such a system. The most important reason however not to choose for a climate control installation was the requirement of the 3 phase power supply for such a system (taking into account the size of this dedicated room), and which fully contradicts my desire to maintain one dedicated phase for the audio groups. All these undesired aspects forced me to investigate other alternatives.
Furthermore I didn’t want any radiators on the walls (taking into account the ‘full’ symmetry requirements and the application of diffusion on all the sidewalls). After investigating several options it appeared that the combination of floor heating in combination with a central heating boiler complied with all my desires. Until recently the combination of floor heating in combination with a wooden floor was impossible, but this changed due to the ‘invention’ of the so-called ‘multi-plank’. These floor parts can be glued directly on a smooth concrete floor and are provided with a thermally conductive bottom layer to enable heating of the dedicated room via the wooden floor. Taking into account the distance between my home and the separate building it was decided to extend the gas pipe to the separate building instead of extending the hot water supply. This actually means that I now own two different central heating boilers (one located in my house and one in the shed). A radiator in the shed is connected to the latter boiler to heat up the shed wherein e.g. my tools, paint, bikes, et cetera are stored to keep it frost-free.
For the ventilation of the dedicated room a ventilation system is installed with a maximum capacity of 6400 [cubic feet/hour] (adjustable in three steps). Fresh air is sucked from outside and is blown into the dedicated room via two ventilation gratings in the ceiling at the front side of the room and sucked out from the room via two ventilation gratings in the ceiling at the back of the room. The installation is further provided with an adjustable heat exchanger to control the energy balance and to prevent undesired energy loss to the environment. By using a time controlled thermostat the installation is configured in such a way that during the nightly hours extra ventilation occurs to force extra fresh air in the dedicated room when it is not used. Possible undesired noise production/vibrations caused by this installation is prevented by supporting the whole installation on dampers and furthermore several silencers are provided in the inlet and outlet channels of the installation. All the measures result in a non-observable noise level in de dedicated room (even not when it is fully quite in the room).
Here some pictures of the current status.
Almost 3.5 years ago I started a thread on a Dutch forum.
There are a lot more pictures shown (including a lot of discussion in Dutch).
I will keep you updated on the progress of this one.
Hope still to learn a lot from all of you!
Best regards,
Jan
My name is Jan and I live in the Netherlands. I'm a music lover and hometheater fanatic for more than 25 years.
Approximately 3 years ago I started building my own movie-theater in my backyard.
I hope to finish this project within the next few months (my goal is to be able to watch a movie before the summer of 2012).
As this is my first posting here on this forum I need some time to get familiar with all the options.
Last status
Still some work to do
The starting point
My starting point for this dedicated listening room / Home Theater is optimizing the audiophile properties of this room with a minimum of concessions regarding this aspect (thus in principle go always for the full 100% unless there are very good reasons (e.g. money / effort) to deviate from this starting point.
The main reason is that in my current situation the ratio between music listening versus watching movies is 90:10. This doesn’t mean that I will cut down the budget on audio-visual means such as a projector and a projection screen, but taking into account all the expenses in relation to this listening room such expenses will shift and can be shifted to a later time-slot (this is also beneficial for me as the current projector market has gone nuts, also here in Europe). While making the planning for this listening room all the aspects of such a listening room (e.g. music listening / movie watching / looks / comfort / …) will be taken into account parallel already from the start of this project (so first fully consider everything from A until Z including all the consequences relating to it and only after that really start with the execution of A).
The final ‘looks’ of this Home Theater are of course also important, but come for me on a second place. When I have to make a decision relating to the acoustical properties of this listening room versus the looks of it, the first property will in almost all cases be decisive. At the end the light is off when I watch a movie and when I listen to music I use my ears and not my eyes. This doesn’t give me however a wildcard to create a very freaky room.
Forces from outside (i.e. my girlfriend) will compel me also to take into account the looks of this Home Theater. She wants for instance luxurious chairs in or a big couch on which she can lie instead of e.g. the well known small red cinema chairs (otherwise she refuses to join me while watching a movie). So here the first concessions need already to be made, although these aspects aren’t on beforehand in contradiction with each other (but you have to consider everything into detail). The colors that I will use are also a compromise, e.g. black is too black and red is too common (but as you can see on the pictures, also here we came to a good solution/compromise).
In summary: this listening room strives for a maximum of audiophile properties for both music listening as watching movies, the visual equipment in the room shall also be optimized and the esthetic aspects will be taken into account, but will never be decisive if this has negative consequences for the audiophile properties of the room.
The name for this listening room is also decided: ‘Confidence Mansion’. My ultimate goal is to build up a complete Home Theater setup using Dynaudio speakers from the Confidence-series. Meaning: Dynaudio Confidence C4’s as front speakers in combination with a Dynaudio Confidence Center and Dynaudio Confidence C1’s as rear speakers (maybe including an extra pair of the latter speakers, if I decide to go for a 7.1 set-up or maybe even a 7.2 set-up). In my current set-up I use a Velodyne DD-18 subwoofer.
During the design phase of this project I will frequently ask for input from people here on this forum, so any tips and / or advices are more than welcome. Hopefully my pursuit for the max will motivate other people to do the same. If you have any questions for me, please don’t hesitate to contact me directly or via a private message.
Best regards,
Jan (a.k.a. ‘Jean Sibelius’)
The Netherlands
The basis: Acoustics
Being familiar with the phenomenon: ‘listening room with problem frequencies’, this project started by making the decision to build a complete new listening room with a minimum and preferably no problem frequencies. My girlfriend encouraged me to do so, as in my current situation our living room is for a big part dominated by the Home Theater set-up. This means however check what is allowed by the local authorities, start with acoustic simulations, go to the blackboard and start building after that your complete garden (including trees and previous buildings) is empty. After discussions with the local authorities that it became clear what the maximum surface and height of the building may be, simulations started. In my situation a maximum surface of 810 square feet and a maximum height of 14.8 feet were allowed. After knowing these values an iterative process started to find the most ideal ratios for the listening room while also taking into account other wishes and requirements. As a consequence of creating so much space in my backyard and creating an opportunity to completely redecorate the garden also my former garage and shed needed to be demolished and therefore also a part of the 810 square feet should therefore also be suitable as a new shed. It was however also decided not to rebuild the garage, so I sold my Pontiac Fiero GT from 1988 (which I owned for almost 12 years).
Within the maximum boundaries available for this listening room length x width x height being (26.3 x 21.3 x 10.5 feet) it appeared that internal dimensions of 24.38 x 19.23 x 9.09 feet would be ideal (meaning approximately 4240 cubic feet effective listening room). The outside dimensions of the complete new building became 35.4 x 21.4 x 14.8 feet (meaning 9360 cubic feet capacity).
Based on these dimensions I contacted an architect to formalize the plans into actual drawings which still needed to be accepted by the local authorities (which succeeded after one iteration). Already in this stage of the project it was necessary to take into account the final finishing of the listening room. It was e.g. decided that the walls would be plastered and therefore the internal dimensions between the walls of the structural work were increased to allow a certain thickness of the plasterwork. Also at this point it was decided that a wooden floor would become the finishing touch on the ground and therefore the internal ceiling height was increased by the thickness of the wooden floor.
In this case it was decided to use a wooden floor and not for instance laminate or carpet, because the laminate would probably result in a very frequency specific damping and the carpet would probably result in an over damped listening room (in both situations it is easier to add specific damping than to remove specific damping).
To control the broadband reverberation time in the listening room a total of 7 bass traps are designed and build, each with their own specific volume and effective frequency. The frequencies of these bass traps are tuned at 46, 50, 63, 71.5, 80, 100 and 122 Hertz. After completing the building of these bass traps an actual RT-60 measurement was done, to verify and to confirm that the simulations appeared to be correct. Damping in the listening room above these frequencies is mainly realized by a plastered ceiling that is placed approximately 7.9 inch below the concrete ceiling and which is furthermore filled with acoustic damping material.
It is furthermore realized and taken into account that symmetry is very important in a listening room. The only asymmetry is caused by the inevitable entrance door, but this asymmetry is solved by applying sliding diffusion panels. These panels are slidable for the entrance door when listening to music or watching a movie. Furthermore diffusion panels will be added on all first reflection points of the front and rear speakers on all the walls (front wall, side walls and back wall) and also on the ceiling. On the sidewalls near the front speakers RPG diffractals will be placed as these have a superior frequency behavior compared with the other diffusion panels. It should be noted that the in total 61 diffusion panels and 16 RPG diffractals also have a damping effect that also should be taken into account.
In the overview below, I wrote down some elementary considerations and decisions that were made while designing and building ‘Confidence Mansion’.
Mechanical aspects of the building
What applies for audio equipment and e.g. audio racks also holds for the building itself. Direct and indirect vibrations that are caused by driving the speakers and subwoofers are preferably not transferred via the floor, walls and ceiling to the other parts of the building and parts inside the listening room that could start resonating. To minimize the excitation of such kind of resonances, special counter measures are applied as discussed below.
First of all, the floor in the listening room on which the speakers and subwoofer will be placed is substantially dynamically decoupled from the rest of the building. The floor is a directly, by cast concrete, formed free floating plate with a thickness of approximately 7.9 inch and an estimated weight of around 44000 pounds, being spring supported by a thick layer of polystyrene foam that is supported on the fixed world, preventing the vibrations that occur in the floor reach the rest of the building.
Furthermore all inner and outer walls in the building are formed by thick and heavy bricks with in between a large cavity that is partly filled with insulating material, forming a total wall thickness of 12.6 inch whereby there is no direct mechanical connection between the inner wall and the outer wall.
Finally the ceiling of the listening room comprises 4 prefabricated floor parts, which are mutually connected with iron reinforcement material and flooded with cast concrete, consequently forming one massive and very heavy plate. The total thickness of this plate is approximately 8.7 inch and has a total weight of around 48500 pounds.
All these measures serve the purpose to prevent that the listening room or parts located inside the listening room start to resonate due to vibrations originating from the vibration sources inside the room. A second aspect of this mechanical construction is that it also forms an mechanical filter for vibrations that originate from outside the listening room (both vibrations via the ground, but also via acoustical excitation). A similar construction, but than in a more extreme embodiment, is present in a special reverberation room at the Philips (NatLab) physical laboratories (located in Waalre, the Netherlands) that is fully acoustically isolated and in which very accurate sound power measurements can be performed. Finally the entrance of the listening room is provided with a special selected door, including special glass to make it as sound proof as possible.
Power supply
At the start of this project some modifications were made to my original current supply to enable the usage of the already available, but not connected, 3 phase power supply being present between the street and the distribution cabinet in my house (meaning e.g. a new power meter, two additional and extra heavy fuses, et cetera). After rebuilding the complete distribution cabinet in my house, the ‘new’ 3 phase power supply was extended to the separate building in my garden to end up in a second (‘3-phase’) distribution cabinet located in the shed. At that location it is measured which of the three phases shows the least distortion and that phase is further extended to the dedicated room and only used for the power supply of the several (in total eight) audio groups. The remaining two phases are used for e.g. lighting and the other power consumers in the building. The second phase is, as a rule of thumb, mainly used for my home and all lighting in the separate building (including that in the dedicated room) and the various wall sockets and the third phase is used for the (potential) big power consumers such as the dedicated air circulation plant, the central heating boiler and optionally an air conditioner.
Choice of the electric power cables
Between the distribution cabinet in my home and the distribution cabinet in the separate building use is made of a 5 x 0.056 square inch (~6mm2) Draka Vulta Mb power cable which is unshielded. Between the distribution cabinet in the shed of the separate building and the distribution cabinet in the dedicated room use is made of 3 x 0.056 square inch Draka Vulta Mb. From the latter distribution cabinet 3 x 0.056 square inch Draka Vulta Mb is used to supply the CEE wall sockets and 3 x 0.025 square inch to supply the HMS wall sockets. The CEE and HMS wall sockets can be used to provide power to my audio equipment. The reason why unshielded power cable is used relates to the presence of undesired capacitive effects of such a shielding. Furthermore it is assumed that power cables are mainly the course of crosstalk, so there where no signal carriers are in the neighborhood, it seems not to be meaningful to use shielded power cables. Taking into account that the whole power supply of the dedicated room is set-up spacious both with respect to volume as power capacity it is possible to locate all power supplying cables far from each other to realize space for all the signal carriers. Furthermore the whole power supply in the dedicated room, is as good as possible, shielded by using a so-called ‘Cage of Faraday’ that is connected to a separate earth contact. At those locations where it becomes impossible to separate power supplying cables and signal carriers (from a practical point of view ‘after’ the wall sockets) well shielded power cables are used to prevent possible crosstalk problems. Incorporating this whole layout of the power supply at the start of this project enabled the realization of this principle idea.
Separate earth contact
For the earth contact use is made of massive copper rods which are mutually connected to a total length of 30 feet. This earth contact is mounted into the ground directly nearby the power cabinet in the dedicated room.
Separate audio groups
In this dedicated room there are in total 8 separate audio groups available:
Group 1. Amplifiers (left) (maximum 4 pieces) using CEE-form;
Group 2. Amplifiers (right) (maximum 4 pieces) using CEE-form;
Group 3. Amplifiers (left) (maximum 4 pieces) using HMS wall sockets;
Group 4. Amplifiers (right) (maximum 4 pieces) using HMS wall sockets;
Group 5. Subwoofers (maximum 2 pieces) using HMS wall sockets;
Group 6. Analogue sources using HMS wall sockets;
Group 7. Digital sources using HMS wall sockets;
Group 8. Projector using a HMS wall socket.
Fuse boxes and fuses
All eight above mentioned audio groups comprise a ‘HMS Klangmodule 3i’ fuse box including a specially designed so-called ‘flat wire fuse’. Although in the current design of the dedicated room it is always relatively easy to approach these fuse boxes, but maintenance of the fuse boxes is undesired (i.e. ‘polishing the fuses’), it was decided to chose for HMS fuse boxes instead of alternative Siemens fuse boxes, although the latter fuse boxes are approximately 50% cheaper.
Wall sockets
The CEE-form wall sockets are wired with 3 x 0.056 square inch (~ 3x6mm2) Draka Vulta MB meaning that these CEE-form audio groups are fully wired with 0.056 square inch electric wires. The HMS wall sockets (type ‘gold-plated’) are electrically wired with 3 x 0.025 square inch (~3x4mm2) simply because there are no audiophile wall sockets (at least as far as I know) suitable for larger diameters of electrical wiring.
Comfort in this dedicated room
An important aspect that by the design and building of a dedicated audiophile/home theater (in my opinion) is often forgotten/neglected is the comfort in the room (i.e. temperature control and sufficient ventilation). My starting point while realizing this dedicated room was to search and find a good solution enabling me to control the temperature in the room (both cooling and heating) but also to provide enough ventilation (and that for all weather conditions in the Netherlands) without making any compromise with respect to the acoustic properties of the room.
A first and straight away choice seems to be to incorporate a complete climate control installation, including amongst others an inner and outer unit to keep the noise levels within specific boundaries. A first drawback of such a system is (according to me) the high installation cost but also the high variable costs due to the relatively high power consumption of such a system. The most important reason however not to choose for a climate control installation was the requirement of the 3 phase power supply for such a system (taking into account the size of this dedicated room), and which fully contradicts my desire to maintain one dedicated phase for the audio groups. All these undesired aspects forced me to investigate other alternatives.
Furthermore I didn’t want any radiators on the walls (taking into account the ‘full’ symmetry requirements and the application of diffusion on all the sidewalls). After investigating several options it appeared that the combination of floor heating in combination with a central heating boiler complied with all my desires. Until recently the combination of floor heating in combination with a wooden floor was impossible, but this changed due to the ‘invention’ of the so-called ‘multi-plank’. These floor parts can be glued directly on a smooth concrete floor and are provided with a thermally conductive bottom layer to enable heating of the dedicated room via the wooden floor. Taking into account the distance between my home and the separate building it was decided to extend the gas pipe to the separate building instead of extending the hot water supply. This actually means that I now own two different central heating boilers (one located in my house and one in the shed). A radiator in the shed is connected to the latter boiler to heat up the shed wherein e.g. my tools, paint, bikes, et cetera are stored to keep it frost-free.
For the ventilation of the dedicated room a ventilation system is installed with a maximum capacity of 6400 [cubic feet/hour] (adjustable in three steps). Fresh air is sucked from outside and is blown into the dedicated room via two ventilation gratings in the ceiling at the front side of the room and sucked out from the room via two ventilation gratings in the ceiling at the back of the room. The installation is further provided with an adjustable heat exchanger to control the energy balance and to prevent undesired energy loss to the environment. By using a time controlled thermostat the installation is configured in such a way that during the nightly hours extra ventilation occurs to force extra fresh air in the dedicated room when it is not used. Possible undesired noise production/vibrations caused by this installation is prevented by supporting the whole installation on dampers and furthermore several silencers are provided in the inlet and outlet channels of the installation. All the measures result in a non-observable noise level in de dedicated room (even not when it is fully quite in the room).
Here some pictures of the current status.
Almost 3.5 years ago I started a thread on a Dutch forum.
There are a lot more pictures shown (including a lot of discussion in Dutch).
I will keep you updated on the progress of this one.
Hope still to learn a lot from all of you!
Best regards,
Jan
