[niknik]

Some nice designs:

http://www.troelsgravesen.dk/Diy_Lou...r_Projects.htm

 

[ooheadsoo]

Actually, amongst a few diy gurus, they quite dislike the original proac 2.5 and cite several design issues which I conveniently can't remember. I think you can do much better. I would hope that the clone would actually sound better, but given the driver choices, which were part of the concern of the diyers not in favor of the original proac2.5, they probably didn't have much choice. I do remember extensive driver mods in attempts to correct undesirable behavior in the clones.

Troels's website was linked to earlier by happyangryhappy.

 

[jpr703]

I'd like to learn more about active speakers (especially DIY designs) and am rather curious about the Orions.

Does anyone have (or know of) any comments as to the quality and sonic signature of the amp and crossover that are recommended in the Orion kit?

The price on those items seems right, but I can't help but wonder if there would be any significant improvement with one of the other high quality multichannel amps out there. The new Bryston 8 channel, for example, looks pretty sweet.

 

[ooheadsoo]

Most engineers who research and develop active designs don't seem to care much about megabuck amp issues as long as they have the requisite specs. I wonder why.

Kreskovsky's transient perfect NaO II system is also active, iirc, and should be worthy of consideration.

 

[jpr703]

Quote:

Originally Posted by ooheadsoo Most engineers who research and develop active designs don't seem to care much about megabuck amp issues as long as they have the requisite specs. I wonder why. Kreskovsky's transient perfect NaO II system is also active, iirc, and should be worthy of consideration.

I've noticed that. I wonder if it's because the tonal qualities of the amp don't show through as much in active systems or if it's because the engineering types just figure an amp is an amp is an amp and design solely by specs.

 

[Wodgy]

Quote:

Originally Posted by jpr703 I'd like to learn more about active speakers (especially DIY designs) and am rather curious about the Orions. Does anyone have (or know of) any comments as to the quality and sonic signature of the amp and crossover that are recommended in the Orion kit? The price on those items seems right, but I can't help but wonder if there would be any significant improvement with one of the other high quality multichannel amps out there. The new Bryston 8 channel, for example, looks pretty sweet.

Almost all of the reviews of the Orions you read are describing the Linkwitz-recommended system (this includes the ATI amp). Embedded within the review will be an implicit discussion of the amp's sonic signature, though it may not be discussed explicitly.

However, you're welcome to use a different amp if you like. Some Orion builders use the Hypex DIY modules, others use Gainclone variations, and of course Bryston gear would be more than capable. The Orion's active crossover means that whatever amp you're using is driving a very easy load with a very smooth, uniform impedance curve. The amp sees only the speaker's voice coil, not a bunch of inductors and capacitors. It's the easiest load you can imagine, so no amp is going to be very stressed. However, the choice of amp may make a small difference in how the tweeter sounds. If you like how Brystons handle the top end (this has improved a lot with the newer Brystons) and have the money, I wouldn't hesitate to use one of the newer Brystons.

 

[ooheadsoo]

If you take SL's recommendation of a minimum of 40w solid state per channel seriously, you have tons of choices. 40w is peanuts. Probably the only modern amps you can get LESS than 40w are $50 receivers and the t-amp. Ok, and maybe some pass labs and other crazy extreme amps like that.

 

[jpr703]

So I take it that the amps sonic signature doesn't have too much effect on the final sound in an active system. That could definitely save a few bucks.

How about the pre-amp? Is it still just as important in an active system as it is in a non active one?

 

[ooheadsoo]

Imo, only your own personal trial and error will allow you to determine your own sense of value for high end electronics. Some engineers do get picky and fussy about their amps, some don't. I wish we all had local shops with nice return policies.

 

[Wodgy]

Quote:

Originally Posted by jpr703 So I take it that the amps sonic signature doesn't have too much effect on the final sound in an active system. That could definitely save a few bucks. How about the pre-amp? Is it still just as important in an active system as it is in a non active one?

The source and preamp are still just as important as before. Linkwitz himself uses an older Lexicon pre-pro; that's probably the weak point in his own system.

 

[Uncle Erik]

Quote:

Originally Posted by ooheadsoo Actually, amongst a few diy gurus, they quite dislike the original proac 2.5 and cite several design issues which I conveniently can't remember. I think you can do much better. I would hope that the clone would actually sound better, but given the driver choices, which were part of the concern of the diyers not in favor of the original proac2.5, they probably didn't have much choice. I do remember extensive driver mods in attempts to correct undesirable behavior in the clones.

You're right, they're not perfect. I think you're talking about the peak around 2kHz. Troels Gravesen worked a notch filter into the crossover that tames that pretty well. I used it. Also, I understand that the originals used iron core inductors. I used Alpha Core air core inductors, with a much lower DCR than the originals and some futzy caps. They really do sound good, and I find that the reviews of the original apply pretty well to the clones. There's a good reason ProAc sold a lot of the originals, originals sell quickly on Audiogon, ProAc still makes a speaker substantially similar, and the clone is popular. While imperfect, they're still a very musical and pleasing speaker.

They might not be the drool-worthy Orions and the AKG K-1000 outclasses them, but it's tough to do better with such a modest investment. The moderate size and clean looks appeal a lot to me, as well.

 

[ooheadsoo]

I'm glad you're happy with your clones! Not my intention to put your project down. I think every project has its drawbacks. I still want a 3 way with 4 or so 10" or 12" woofers on each side on the bottom to reduce distortion, but what a cabinet that'd be, eh?

The driver mods I was referring to included things like applying glue to the surround and things like that, not an electrical filter. I remember it was originally in Troels pdf on the project. I haven't read it in years.

 

[Wodgy]

On the topic of the ProAc 2.5 clones, someone is currently selling a pair on the Madisound forum, if anyone's interested in buying rather than building.

 

[magnetik]

Quote:

Originally Posted by intlplby thanks for the info two more questions: what are some good sites on how to work with the wood including information about tools needed and whatnot? I'm not familiar with working with wood. what's considered the best pair of 2-way shelf speakers? Something that can be used in a small office or a small bedroom. i should probably start with something simple like that before embarking on some huge mission

you can checkout my worklog for my tempest sub. I have a lot of woodworking (even laminating) tips on it. Might not be as fancy as some others but you might pick up some things from it. It's also from a woodworking noobs standpoint.

DIY Tempest Subwoofer

 

[Wodgy]

That's a fantastic DIY sub project. You did a great job. It seems that probably the majority of speaker builders get started with sub projects.