Ultimate Class D amps for active speakers

[Silent Screamer]

I have been doing some research (as good as one with little electrical knowledge can) and I have been looking for some direction on amps for some new active speakers.
I am caught between doing something DIY and buying something off the shelf. From what I can gather the actual cost of decent Class D stuff is minimal, but you can easily wind up paying a lot of money for a fancy box if I go commercial.
So probably the best place to start is if I tell you what I am trying to drive and we can go from there…

Each active speaker will have the following:
1 x RAAL 140D-15 AM Tweeter
2 x ScanSpeak Illuminator 12MU8731T00 (in parallel for a 4ohm load)
Mid Woofers and Woofers are still undetermined but will be of the same quality level or better than the above

I have just spent ~$4500 purchasing a Ground Sound DCN 28 active cross over, so spending a few more dollars is not an issue, but at the same time I don’t want to throw money away just for the sake of it.
Since I am going active and I am building the speaker boxes myself it would be more convenient if I went the DIY route and built the amps into the speakers, but I am concerned about buying an inferior product to what I can buy commercially.

Not having the electrical savvy to know when I am just paying for marketing hype, I would really appreciate the advice of anyone who knows quality amplifiers to give me some direction on what I should buy.
I am currently using a Rotel RB-1092 for some passive speakers, I would like to step it up another level from there if possible.

For those not familiar with the Rotel’s Class D amp please see these links…
http://www.hometheaterhifi.com/volume_14_1/rotel-rb-1092-amplifier-1-2007-part-1.html
http://www.hometheaterhifi.com/volume_14_1/rotel-rb-1092-amplifier-1-2007-part-2.html
http://www.hometheaterhifi.com/volume_14_1/rotel-rb-1092-amplifier-1-2007-part-3.html

I am wanting to build some killer speakers and don’t want the amps to be the weak link in the chain. I have been reading about Hypex NCore NC400 are they up to the job above, or do I need something better?

[_henry_]

hi silent,

im in similar position as you, RAAL + SB Satori + Exodus Anarchy in modular cabinets, dual woofer on top and bottom, with raal and satori in the middle with MTM config.

i think nc400 is one of the best solution (if not ultimate) for DIY, its just that it might be too much power raal.

i got 4ch classdaudio sds-470 on hand, and looking to order for more class d from connexelectronic (cheaper solution).

i got motu828 and tc konnekt48 for the active management, and also considering miniDSP 4x10hd for better user friendly approach.

where u about in sydney? im in castle hill.

cheers
henry

[_henry_]

btw,

NC400 is very easy to assemble, minimum soldering.

cheers
henry

[qusp]

for the ultimate, for Class D, yes the NC400 seems about as good as it gets. building class D from the ground up as an ultimate solution with little experience is not an option, buying finished modules is really the only way forward IMO. it certainly is enough power to melt your tweeters though if you make a wrong connection, or just with a turn on pop.

just wondering, any reason you didnt consider digital active? the possibilities to also create the ultimate room by removing it from the equation come into play with that option.

i'm not sure how you came to the conclusion that there isnt much to class D design/cost. sure there are integrated simple Class D chips that cost very little, but they dont give performance equal to the speakers you are planning IMO. there are also some of the Bang & Olfsen Icepower modules on sale in the sales thread here for a good price at the moment and theyve gotten excellent reviews also.

[qusp]

have you built speakers before? do not make the mistake of thinking if you throw enough money at drivers and amps that you will by default, with little effort, get a better solution than the same spent on commercial designs. An electronic crossover doesnt somehow make designing a great crossover easy, particularly if you arent going with a published design, or well documented driver combination

[_henry_]

at least you will need some measurement equipment.
there's always time and space to learn



cheers
henry

[qusp]

Originally Posted by _henry_

at least you will need some measurement equipment.
there's always time and space to learn



cheers
henry

oh absolutely no question you can learn on the job so to speak, but lets just say I wouldnt be choosing RAALs and a few K worth of other drivers to 'learn' with.

to have a finished system could take the best part of a year no problem at all and could very well include a few cabinet designs, some different drivers and a different crossover solution.

many veterans taking on a reference build at the pointy end will be buying 2 or 3 of everything and measuring the different combinations

[_henry_]

at least knowing that you made some big investments the harder you will try to get that "final" result.

you can always get the general idea as a reference with projects available in the net or even on commercial offerings.

for instance, rick craig from selah audio used Parts Express mdf enclosure with expensive drivers such as accuton, raal and scan illuminator. of course rick's knowledge and expertise regarding x-over designing play major part of the successful designed Tempesta.

so enclosure aside, its mainly down to driver positioning, measurements, adjustment of freq cutoff and eq with personal taste of sound that can lead to successful diy project.

at least for active system point of view. :d

cheers
henry

[Mark.Clappers]

That's a very nice and expensive setup!

Hypex nCore is a very nice amplifier for such a speaker, there's a hugh thread discussing it's pro's and con's here on DIYaudio. For the tweeter just make sure you have a coupling cap in the signal path (after the amp) as the nCore is DC coupled!

Also be sure to also invest some money in measurement equipment, something like ARTA + an external soundcard + a good measurement mic.

Good luck with your project!

[Silent Screamer]

Thanks guys, no there not the first set of speakers I have built, back in the 90's I did it the hard way with a passive 3.5 way with some Vifa P17WJ drivers, to this day I still think they sound great for what they are.

As for reference I currently own a set of Sonus Faber Cremona floor standing speakers for a reference.

Yes bought a decent microphone to help set up the cross over software / room correction.

Have some Solen 8.2uF caps to go on the RAALs but will be swapping to some Mundorf gold caps once they have stock.

I remember the constant swapping of hard wired parts last time, so I am looking forward to being able to digitally adjust it this time

Really don't want to do any serious soldering myself, I bought a digital temperature controlled soldering iron the other month for some light soldering, but I definitely want the modules pre made.