Hi, Thanks for a great and inspiring Forum.
I am building a Basement hometheater and i am just about to put 5 speakers into production.
I will update this Thread as the project Progress.
I have Bougt the amp (denon x3700H)
and the drivers ( mark Audio Alpair 12p x 5)
I plan on buying 4 more for the atmos chanels when i build the ceiling.
Plan is to end up with a 5.2.4 atmos system with only alpair 12P + woofers
The woofers will be Infinite baffles 15 og 18 inches which i will build into the front wall of the theater.
The raw room dimensions are 4.5x5.5 meters
Since i am using subs i dont need enclosures that extend the bass "artificially" i was looking at the MarKen classic golden ratio.
The only thing i dont like about the CGR is the asymmetry, which is why i made some adaptations. i wanted to split the port and have one port on each side of the driver like so:
To the far right is the shape of the CGR to illustrate the origin of the design.
It will be made in 18mm birch ply.
I am just about to start production, so any input you guys have is more than welcome.
Should i for insance make any changes to port lengths when splitting it up on several smaller openings that combine to a larger "opening mouth"
- David
I am building a Basement hometheater and i am just about to put 5 speakers into production.
I will update this Thread as the project Progress.
I have Bougt the amp (denon x3700H)
and the drivers ( mark Audio Alpair 12p x 5)
I plan on buying 4 more for the atmos chanels when i build the ceiling.
Plan is to end up with a 5.2.4 atmos system with only alpair 12P + woofers
The woofers will be Infinite baffles 15 og 18 inches which i will build into the front wall of the theater.
The raw room dimensions are 4.5x5.5 meters
Since i am using subs i dont need enclosures that extend the bass "artificially" i was looking at the MarKen classic golden ratio.
The only thing i dont like about the CGR is the asymmetry, which is why i made some adaptations. i wanted to split the port and have one port on each side of the driver like so:
To the far right is the shape of the CGR to illustrate the origin of the design.
It will be made in 18mm birch ply.
I am just about to start production, so any input you guys have is more than welcome.
Should i for insance make any changes to port lengths when splitting it up on several smaller openings that combine to a larger "opening mouth"
- David
First, search out all the reasons why translam is generally a bad idea.
The centre channel you want is already done (and more elegantly), and with Joan now available, an Alpair 12p centre moves from the paid planset, to free for diy use status.
Needs some tidying so this link will disappear.
https://frugal-horn.com/downloads/centre/A12-centreB.pdf
dave
The centre channel you want is already done (and more elegantly), and with Joan now available, an Alpair 12p centre moves from the paid planset, to free for diy use status.
Needs some tidying so this link will disappear.
https://frugal-horn.com/downloads/centre/A12-centreB.pdf
dave
Update:
Finaly got 3 speakers finished.
Build as sealed golden ratio boxes for simplicity.
I know its stupid to build with stacked plywood for looks, and then hiding them behind screen.🙂
Sounds great after a few days of breaking in. stil many hours of breaking in left before i can start experimenting with stuffing and tweaking of internal volume. I also need to treat the room, but one step at the time, and ill get there eventually.
audyssey xt32 room correction of the denon x3700h helps a lot as it is now 🙂
screen is diy lycra ($60) and is 120" 16:9 It works surprisingly well. I can blow through it and can feel my breath on my hand and i can hear no difference with or without the screen up.
Finaly got 3 speakers finished.
Build as sealed golden ratio boxes for simplicity.
I know its stupid to build with stacked plywood for looks, and then hiding them behind screen.🙂
Sounds great after a few days of breaking in. stil many hours of breaking in left before i can start experimenting with stuffing and tweaking of internal volume. I also need to treat the room, but one step at the time, and ill get there eventually.
audyssey xt32 room correction of the denon x3700h helps a lot as it is now 🙂
screen is diy lycra ($60) and is 120" 16:9 It works surprisingly well. I can blow through it and can feel my breath on my hand and i can hear no difference with or without the screen up.
Setup is looking good so far! What made you decide to go with the alpair 12p? What sort of SPL are you targetting?
Using stacked ply is definitely not the most efficient use of material but if exposed birch ply is the look you are after then go for it! Calling it just stupid is ridiculous. Some of the most influential speakers in the last 2 decades have been utilizing birch translam for there cabinets...
Speakerwire diskussion is dangerous territory so i Will not be discussing this, nyt just describe what i have chosen very deliberately.
Wire is 4mm2 Cooper Coated aluminium so they are thicher than pure copper. All speakerwires are Long and equal in lenght (12 m) in order to reach receiver and keep identical cable resistance to each speaker. Wire is soldered to the loose spade conector that comes with the alpair. No terminals on back side of speaker. Just two sealed Holes wiht Wire sticking out.
I chosen them because they have little Beaming compared to other full Range which is necesarry wiht multiple Guests in cinema and future atmos ceiling mounts in my fairly low ceiling. I want identical units in All Chanels.
Regarding Spl, i dont want to push Them too far just yet, but they Seem fully capable of surpassing my comfortabke listening volume without a hint of Distortion or breaking Up.
Normal listening levels are with the Denon volume set to 60/100 ... 70 starts to get uncomfortably loud.
Audyssey registered them as small and wanted to cross them at 90hz. upped that to 110 hz.
subwoofer is an old DALI asw-12