Bi-amping my 1.2TLs

tugboat
tugboat Posts: 393
edited December 2009 in Vintage Speakers
Okay, here's the deal. I have discovered how to bi-amp my 1.2TLs by using the rear channels and multi-room setting on my Denon 5803A. Basically the channels I now use for my 7.1 will be reassigned to the multi-room setting that will mirror what's playing on the mains. This will mean I'll be back to 5.1 for my HT, but that's okay for now. What I need help with is how I should calibrate the amps. Should I perform the process below using the built-in noise generator or use and external generator? If external, what should I use...white or pink?

I am going to use my SPL meter on the front speakers to get a reading, then hook the speakers up to the rear amps and adjust the levels up/down to match the reading from them running on the main channels. Once I get them equal, I'll remove the jumper and connect the front channels to the highs and the rear channels to the lows. All amps are common ground, but if they weren't, I'd just connect the AI-1.

If I remove the jumpers, are the individual inputs still the same ohm rating? From the papers I have with these speakers, they are 6 ohm nominal. Is that still true for each input or does the rating change? Currently the Denon is rated at 200wpc into 6 ohms, so if they stay at 6 ohms, that'll be 200w for each input. If it changes to 8 ohms, then they'll be 170w for each input.

I am expecting my order from Blue Jeans Cable this week (10ga), so I hope to have this completed real soon. :)

Thanks!
Driver carries only 20 dollars in ammunition

Pedestrians have the right of way, unless they are in the way
Post edited by tugboat on
· Share on FacebookShare on Twitter

Comments

  • ben62670
    ben62670 Posts: 15,969
    edited August 2008
    You are fine with the Ohm ratings. There should be a level adjust to keep the tweeters happy. You should be able to hook up a laptop, and use a free signal generator to set the highs, and lows on the 1.2's
    Ben
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
    · Share on FacebookShare on Twitter
  • awe-d-o-file
    awe-d-o-file Posts: 146
    edited August 2008
    The receivers outputs are common ground too. Ultimately the setting should be how you like it. If thats a few db higher or lower than proper or flat so be it. You can use a voltmeter set to AC to measure the output.


    ET


    ET

    System: MF Trivista SACD > Placette passive> CJ passive horizontal bi-amp> MF 2500A(LF) MF2100(HF) > 1.2TL's

    Other: Speltz silver Eichmann IC's & speaker wire, Econotweaks Detail Magnifiers, PS Audio P-300(source), R. Gray 600, Al Sekala's AC R/C filters, R. Gray HT PC's, Oyaide R-1's,WPC-Z , M-1, Herbie's & DIY Isolation
    Room: Qty 7 - 4' tall 18" diam. bass traps, Qty 4 - 4' X 2' X 4" panels. All DIY - man my wife is tolerant!
    · Share on FacebookShare on Twitter
  • tugboat
    tugboat Posts: 393
    edited August 2008
    awe-d-o-file wrote: »
    The receivers outputs are common ground too. Ultimately the setting should be how you like it. If thats a few db higher or lower than proper or flat so be it. You can use a voltmeter set to AC to measure the output.


    ET

    I was thinking the same thing. If I set my DMM for AC, play a 1kHz sine wave, check the AC voltage of one channel and adjusted the other channels to match the first one's AC voltage, wouldn't that give me 4 channels at the same output level?
    Driver carries only 20 dollars in ammunition

    Pedestrians have the right of way, unless they are in the way
    · Share on FacebookShare on Twitter
  • ShinAce
    ShinAce Posts: 1,194
    edited August 2008
    Correct, for a pre-made speaker you want to bi-amp, you would voltage match the amplifier outputs.

    Any efficiency differences are settled by the crossovers.
    · Share on FacebookShare on Twitter
  • john E
    john E Posts: 32
    edited December 2009
    I don't like how they have the Monitor 70's or 60's to biamp.You are putting all that power just on the tweeters and the other power on all your other speakers.It look like it would make it easier to blow your tweeter.I think on the 70's they should have split it up better ,like put the mids and tweeter on one channel and your bass on the other channel.
    ONKYO TX-SR607
    PolkAudio Speakers
    Front-Monitor 70's
    Center-CS2
    Sur-round-Monitor 40's
    Sur-round Back-Monitor 60's
    Subwoofer-PSW-505
    Back fill in Bass PSW-10
    LG 50"Black 1080P Plasma HDTV (50PS60)
    LG Blu-Ray Disc BD390
    · Share on FacebookShare on Twitter
  • comfortablycurt
    comfortablycurt Posts: 6,745
    edited December 2009
    john E wrote: »
    I don't like how they have the Monitor 70's or 60's to biamp.You are putting all that power just on the tweeters and the other power on all your other speakers.It look like it would make it easier to blow your tweeter.I think on the 70's they should have split it up better ,like put the mids and tweeter on one channel and your bass on the other channel.

    The tweeter is only going to draw as much power as it needs at any given time. If anything, you're less likely to blow it like that.
    The nirvana inducer-
    APC H10 Power Conditioner
    Marantz UD5005 universal player
    Parasound Halo P5 preamp
    Parasound HCA-1200II power amp
    PolkAudio LSi9's/PolkAudio SDA 2A's/PolkAudio Monitor 7A's
    Audioquest Speaker Cables and IC's
    · Share on FacebookShare on Twitter