[jonirvine]

So I have all my sources running into a Marantz 1402 with my mains being powered by two amps coming out of the preamp (a Music Angel tube amp and Alesis RA300 power amp).  The MA powers the Full ranges and the Alesis powers two pairs of 15" Eminence Alpha's (Open Baffle). My question is what is the protocol for setting the levels of all 3 amps?  I mean, there's little I can do with the Marantz since it's acting as my volume conrol but I did run the audessey for room correction when I'm in home theater mode.  The main problem I'm having is setting the levels for the other 2 amps.  Is there a process I should follow so all 3 amps mix well?  Or is it all by ear?

[doug s.]

final settings should be by ear.  but, i would recommend getting an equalizer/spectrum analyzer w/pink noise generator and mic, so you can measure frequency across the entire audio spectrum, and adjust the amp's wolumes accordingly for flat response.  this would be the minimum you would need to do, methinks.  you can usually find these for not too much money on ebay.  there are also software iterations awailable now that let you do this on a computer.  there's cd's you can buy for ~$20 or so that run pink noise and test tones at warious frequencies; w/that and a rat shack db meter, you can adjust levels of your amps.  i have one of these, but i paid a bit less than half the asking price, and i got a mic:

http://www.ebay.com/itm/110840868436

once you know the proper levels needed, if you cannot adjust the wolume of each amp separately, and there is a level imbalance, then you could use in-line attenuators to come close to wolume matching.  harrison labs and goldenjacks sell in-line attenuators at warious db-levels..  or you could get fancier, and get scott endler's attenuators that allow for 12b or 24db level adjustments.  these are basically mini passive preamps...

http://www.goldenjacks.com/

http://www.parts-express.com/wizards/searchResults.cfm?searchFilter=&srchExt=MFG&perPage=99&sortBy=1&layout=grid&page=1&srchPrice=&srchCat=725&srchMfg=265

http://mysite.verizon.net/vze4c5pt/id2.html

doug s.

[jonirvine]

oh fantastic!  i have one of those radioshack spl meters and an iphone app that can generate the frequencies!  Finally can put them to good use.  thanks doug!

[doug s.]

good luck, jon; i followed your jamo clone build; nice work!   

i also agree w/the sentiment over that that going active/dsp will give best results...

doug s.

[pelliott321]

I use TrueRTA on a laptop with the Bheringer 9000 mic and M-Audio AD. I use the program to generate Pink noise and mic picks up audio from the speakers and graphs the results.  Very easy to flaten out the curves using levels on amps.