New Year Home Theatre Project

[Allanvh5150]

Hi all. Here is the new project for the year. I was toying with the idea of charge coupling all of my cabinets, 2 x L150, 2 x L150A, 2 x L86 and a custom centre. I have decided to go down a very different path:

Make the whole lot active.

This involves building 15 x 50 watt amplifiers, 7 x 250 watt amplifiers and for good measure a pair of 600 watt per channel amplifiers for the subs. Bit of a mission really. Each cabinet will have a dedicated amplifier that contains 1 x 250 watt for lows, 1 x 50 watt for the mid's and 1 x 50 watts for the hi. There will also be a 3 way linkwitz reily crossover with individual 24 step hand made attenuators. Toroid transformers will be used throughout complete with soft start and thermal shutdown. A pair of thermistor controlled fans within each box and also speaker protection for the Mid's and Hi's. Balanced inputs and Speakon outs will top off the connectors on the back and maybe even a Toslink in, haven't given that a lot of thought as yet.

The cabinets are the sticking point at the moment. Bead blasted aluminium plate and some type of exotic wood sounds pretty cool but that is down the track a tad.

Should be pretty interesting few months. Hopefully there will not be much smoke. Thoughts?

Allan..

[1audiohack]

Sounds VERY ambitious! It will be fun to follow along.

My new years audio resolutions are far more benign.

[Don C]

Bead blasted aluminum is difficult to keep clean, and very difficult to clean. Unless you clean it by bead blasting it again.

[pathfindermwd]

Hi all. Here is the new project for the year. I was toying with the idea of charge coupling all of my cabinets, 2 x L150, 2 x L150A, 2 x L86 and a custom centre. I have decided to go down a very different path:

Make the whole lot active.

This involves building 15 x 50 watt amplifiers, 7 x 250 watt amplifiers and for good measure a pair of 600 watt per channel amplifiers for the subs. Bit of a mission really. Each cabinet will have a dedicated amplifier that contains 1 x 250 watt for lows, 1 x 50 watt for the mid's and 1 x 50 watts for the hi. There will also be a 3 way linkwitz reily crossover with individual 24 step hand made attenuators. Toroid transformers will be used throughout complete with soft start and thermal shutdown. A pair of thermistor controlled fans within each box and also speaker protection for the Mid's and Hi's. Balanced inputs and Speakon outs will top off the connectors on the back and maybe even a Toslink in, haven't given that a lot of thought as yet.

The cabinets are the sticking point at the moment. Bead blasted aluminium plate and some type of exotic wood sounds pretty cool but that is down the track a tad.

Should be pretty interesting few months. Hopefully there will not be much smoke. Thoughts?

Allan..

So you're basically talking about making powered- towers like the current offerings of powered monitors? That sounds pretty cool to me!

Are you thinking about building new cabs (didn't follow that part)? If you are talking about how to hide the amps and electronic crossover, you could build a box base that hold's all of it, though the L150's are pretty tall already. If you mount them to the back of the cabs you could build a box- frame covered with cloth that matches the grill cloth, and make it removable just like the grills.

I have been wanting to actively bi-amp my L100T3's for awhile, so this would be a very interesting project to follow!

[pathfindermwd]

Bead blasted aluminum is difficult to keep clean, and very difficult to clean. Unless you clean it by bead blasting it again.

My friend is in the sandblasting business and what they did for a job was to sandblast steel to a white-grade, and then to clear coat it, gave it a "pewter look". I did something similar with the aluminum 2214's on my L100S's that did not have the machined edge, I used a rough sandpaper to take the paint off and give them a machined look, then clear coated them, they match the T's 2214's (edge) very well.

[Allanvh5150]

Are you thinking about building new cabs (didn't follow that part)?

The idea is to build an amplifier that will be on show. Wood and metal. I have acces to metal working CNC's so nothing is really a problem. The only "case" problem I have is designing something that looks good. The electronics are a doddle.

Allan.

[pathfindermwd]

Each cabinet will have a dedicated amplifier that contains 1 x 250 watt for lows, 1 x 50 watt for the mid's and 1 x 50 watts for the hi. Allan..

This made me think that you were going to mount the amps to the cabs, is that not right?

The idea is to build an amplifier that will be on show. Wood and metal. I have acces to metal working CNC's so nothing is really a problem. The only "case" problem I have is designing something that looks good. The electronics are a doddle.

Allan.

So the L150's have wood veneer sides, black painted fronts, and aluminum drivers. If you like the looks of them you could make the equipment matching?

How about some 1950's retro theme? Can you make an amp who's aluminum faceplate has a winged effect, like the cars of the era? Some cool protruding bullet lights/knobs?

http://www.google.com/imgres?q=1950's+design&start=15&hl=en&client=firef ox-a&rls=org.mozilla:en-US:official&biw=1024&bih=430&tbm=isch&tbnid=zdyXFy-yiN78pM:&imgrefurl=http://vintagraph.com/1950s-design/single-gallery/8248706&docid=H6VGMunDw21yOM&imgurl=http://vintagraph.com/picture/nothins-new-like-chevy-1959.jpg%3FpictureId%3D8248706%26asGalleryImage%3D true&w=525&h=343&ei=sB4AT-W4J8j20gGni9SYAg&zoom=1

Too crazy?

[pathfindermwd]

Something like this would be an interesting design to see anytime, especially in a home. As a tri-amp, it would have alot of wires coming out of it!

https://www.cee.siemens.com/web/ua/e...rview=nwaprint

[Allanvh5150]

Something like this would be an interesting design to see anytime, especially in a home. As a tri-amp, it would have alot of wires coming out of it!

https://www.cee.siemens.com/web/ua/e...rview=nwaprint

Ha! Strange you would show that pic. My wife is Ukrainian.

[pathfindermwd]

Ha! Strange you would show that pic. My wife is Ukrainian.

Then the WAF should be high!

[pathfindermwd]

But seriously... The transformer design would be really cool for so many reasons. First, the idea of transforming power into music. The high power/voltage "look". It's definitely unique! And finally, you won't have ever have to get behind the thing to check connections, it's all right up on top. Not stack-able, but if you wanted stacks of equipment, you could buy that. Also, it could be a design that might look oddly sinister sitting atop the speakers, if you did want to get them as close as possible. I think you could make it classy looking with wood added to the sides. If you use it, will you make me a pair for my speakers?

[1audiohack]

Bead blasted aluminum is difficult to keep clean, and very difficult to clean. Unless you clean it by bead blasting it again.

If left rough and raw, that's very true. If your talking about lightly round bead blasted to create a smooth satin finish, if you type two anodize it and properly seal it, (cold water rinse) that is very easy to keep pristine looking. I have a remote control that has been in my grubby hands for two years and it looks as new.

[Allanvh5150]

I hate design work. I always think up the basic circuit idea and then try to build in a lot of features. The active crossovers are designed, schematics have gone to my board designer in the States. Hopefully the board design will be done in a week or so. Power amplifiers are all but ready to go. The power supplies are ready to go, one is +-70 volt with 60,000uf of filter for the 250 watt amp, the other is +-35v with 40,000uf of filter for the Mid and Hi amplifiers. There are some smaller supplies as wel: +-18v for the crossover, 12v for each fan. I have 2 120mm fans in each box. These will run at 30% most of the time for the simple reason, to keep them quiet. Ach fan will have a separate thermistor controller to enable the fan speed to increase if needed. I have decided to put a vacuum tube VU display in for each channel: no LED's here! Hopefully I can crank up the CNC mill next week and do one of the front panels, probably from 20mm plate aluminium. Fun fun fun.

Allan.

[Allanvh5150]

Well progress is not too bad. All the amplifier modules are done. +-18v power supplies are done. I have built and tested the 12v supplies for the fans which are also thermistor controlled to increase in speed as the temperature rises. Cases are designed but I have not had the chance to start any machining yet. I thought this would be a relatively simple project but it has ballooned somewhat. I have soldered up 10 of the attenuators, they have 24 resistors on each of them. The only electronic components left to test, are the crossovers. I am waiting on the PCB's. I will probably get some pics up soon.

Allan.

[Hoerninger]

... I was toying with the idea of charge coupling all of my cabinets ... I have decided to go down a very different path.

Good luck for your ambitious project .

What about charge coupling the capacitors for the tweeters?
Would you be so kind and share some infos about the amps? (aussie-amps?)
____________
Peter