amps for a 3-way open baffle system

lurer

Member
2007-07-02 12:24 pm
Hi,
I am slowly but steadily working to realize my dream. A 3-way Open Baffle setup with active crossover. Crossover will be software based on a PC connected to a pro sound adapter like Lynx or similar.
Speakers will probably be dual AE Dipole15's, a Dipole6 and a RAAL tweeter.

After a quick count i would need 6 mono amps or two 3-channel amps.

Im looking for a DIY kit that is relatively compact and where power supply also can be fitted nicely next to the amp.
Because i need so many i would like some suggestions that are not too expensive, but the quality of the sound is the most important.
Around 70-100watts per amp in 8 ohm would be nice.
If there are some ready made cases on the market i could fit the amps in, i would be happy to know about that too :)

So, anyone have any suggestions?
I'll answer questions happily if you need any more information ;)
 

lurer

Member
2007-07-02 12:24 pm
Thanks for the reply Adam.
Looks like they sell minimum of a 100?
Anyways. I guess i wasnt very precise when saying not too expensive.
$2-300 for one amp and a powersupply is okey, but if there are cheaper options with great recommendations from guys in here, i will keep those in mind when the time comes.

I have noticed these sites, and there are some interesting products there. I just dont know if they're good enough.
High End Audio MOSFET Amplifiers
Power Amp Kits by AmpsLab
Audio Amplifier Modules & Electronic Kits
41Hz Audio:Sounds Good to Me!

(Also know about Hypex UcD alternatives).

Are there anything worth mentioning from these companies? I guess there are a lot more out there, so please dont be shy hehe.
This is a project stretching two years into the future, so im in no hurry, I'm just buying computer and Lynx Two-b now this week, so money will need to save more money ;)
 
Yes they do sell in higher quantities but they have told me that it is possible to order some samples. Given the price it might be interesting to try.
Anyway, what i heard, the Hypex is one of the best, the UcD180HG module could be the one for you. Also one of the owners of the Hypex company is to be found here and he is very helpful so i recommend you to discuss directly with him.

Good luck with your project !

http://www.diyaudio.com/forums/members/jan-peter.html
 

SAC

Member
2007-02-15 12:43 pm
London
I am in the same boat with a 3/4way active system, open baffled alpha15s, B200, Monacor mid, and neo3 tweeter. I was well set on the 41Hz amp 9, especially since 41Hz now sells them pre-assembled at 75euros each. The third and fourth channel can be connected in the case of your 3-way.

Certainly one of the better bang for bucks out there, and with a 24V PSU the amp9 will run with lower distortion at higher output levels.
 

lurer

Member
2007-07-02 12:24 pm
Hypex is a good option for me. Also the guy that im buying the Lynx Two-B from today recommended it. Buying the HG-module in Norway still is at the top end of my budget, so we'll see.
Low distortion is for sure one good feature that will be part of my decision. The AE drivers are known for very low distortion, so why ruin that with the wrong amps :)
 

lurer

Member
2007-07-02 12:24 pm
I (think I) have heard or read somewhere that if you have a normal two-way setup with a stereo amplifier and the speakers demand a 180W per channel to perform optimally, then a you could manage with four amps/channels at 35W (70W per speaker) if you have a active crossover. This because the total load within a limited frequency area is much smaller, and impedance per driver is easier to handle than all the impedance variations over the whole frequency from both drivers combined.

Is there any truth in this? It does seem easier to handle lets say 20-2000hz than 20-20 000hz, and one would experience alot less impdance variations within one drivers operation area than the two combined.
 

SAC

Member
2007-02-15 12:43 pm
London
I cannot comment on the numbers but I have read the exact theory you describe from experts such as Linkwitz-Riley. Since the amps are working at a lower power output, they therefore stay within their lower distortion range.

It can therefore be said that in some cases, cheap amps through active crossovers - since they are cruising at lower power levels - can beat expensive amps going through passive speaker level crosovers.

Check out the amp9 distortion figures into a 4ohm load at 24V on the data sheet for a good example.
 

lurer

Member
2007-07-02 12:24 pm
One more question.. This is about impedance matching.
When running an active crossover on the computer and six analogue outputs from Lynx Two-B into the amps, impedance difference in the Lynx outputs and lets say Hypex UcD inputs could create unwanted problems, or am I wrong?

Here, my lack of theoretical knowledge is again surfacing :)
UcD400 has Input impedance of 100k, and Lynx's unbalanced outputs are 50 and the balanced outputs 100. Is that ohm or k-ohms?

I might be totally off here, but i do what i can to be sure nothing is going to surprise me in a negative way.
What is normal procedure if you have this kind of situation?

http://www.lynxstudio.com/nav/getFile.asp?i=35&t=productfile
http://www.hypex.nl/docs/UcD400HG_datasheet.pdf
 
Sorry to hijack, but i'm planning to do something similar, I use 4 drivers per side and plan on using one sure 4X100 tk2050 per side integrated into the base. One question I have, 3 of the drivers are rated for an 8 ohm load but the mid is only 6 ohm apart from the obvious difference in spl if all amp channels were set to the same level are there any other issues i should be worried about e.g. reliability due to the differing loads? Also would a 10amp 24v smps be enough for all 4 channels?
 
I (think I) have heard or read somewhere that if you have a normal two-way setup with a stereo amplifier and the speakers demand a 180W per channel to perform optimally, then a you could manage with four amps/channels at 35W (70W per speaker) if you have a active crossover. This because the total load within a limited frequency area is much smaller, and impedance per driver is easier to handle than all the impedance variations over the whole frequency from both drivers combined.

Is there any truth in this? It does seem easier to handle lets say 20-2000hz than 20-20 000hz, and one would experience alot less impdance variations within one drivers operation area than the two combined.


Yes, that is true and i have seen a lot of good active speakers with smaller amps for the midrange and treble sections, sometimes biased to pure class A and powerful woofer section in AB. Good example is ATC SCM 150 ASL, distibution is :
HF 50 Watts RMS
MF 100 Watts RMS
LF 200 Watts RMS
 

lurer

Member
2007-07-02 12:24 pm
I have today been at the local dealer of Hypex modules. We had a good talk and basically I have decided on the UcD400HG HxR. A pair of these will for a good while now be the main amp in my two way setup until we buy an appartment. Big OB-speakers will not be welcome in the living room right now :)