QLS dimensions

Discussion in 'Infinity Loudspeakers' started by AirCombatGuy, Mar 15, 2017.

  1. AirCombatGuy

    AirCombatGuy New Member

    I've owned a pair of Q2's since they first came out, love them a lot, but regret that I didn't pop for the QLS. The attached file contains a CAD drawing of a QLS derived from the photo in the Infinity brochure. I would very much appreciate someone who owns a QLS verifying the various dimensions. I have been bitten with the speaker building bug and am contemplating creating a QLS look-alike (Watkins woofers, but everything else new). I've seen the QLS and Q2 hybrids folks have created, so they give me some confidence that this is do-able.

    Saw the amp thread, and for the record I push my Q2's with an Adcom 5802. Previously used a Bryston 4B and before that a Dynaco 400 (which surely dates me!). None of them have had any issues with the Watkins.

    In the drawing, the woofer, mid-bass coupler, dome mid-range and tweeter diagrams were all derived from direct measurements on my Q2's (and I have CAD drawings of them as well).

    Attached Files:

  2. 7.62

    7.62 Gearhead Subscriber

    Las Vegas
    I'm not sure if they're the same but I have a pair of quantum 5's in my office, Watkins 12 inch Woofer, with the dome midrange and emit Tweeters. If you would like actual dimensions from these no problem.
  3. SicMan

    SicMan Fire up those speakers Subscriber

    Wolcott - CT. USA
  4. slimpikkins

    slimpikkins Super Member

    South East PA
    Sounds like a fun project. I have the original QLS1 with the black front. My mid bass coupler is a little lower than what you have. From floor to center it is around 25 1/4". The bottom edge of the first mid dome is in line with the mid bass couplers center. Center line between the mids is 6". Bottom of the bottom tweeter is 21 3/4 from the floor. Edge of the cabinet to center of the tweeters is 3 1/2. Center of mids is 7 1/4. My base is around 7" high with 3/4" space before the main box and base.
    Hope this helps.
    chef free likes this.
  5. chef free

    chef free AK Subscriber Subscriber

    Oakland! What?!
    This is a very interesting idea! I'd like to know more about the drivers you plan to use, what will you use for the mid domes? The rest of them are pretty available.

    I think the weakness of the QLS-1 is the fact that they sound so different when I stand up or sit down. The problem is the mid bass coupler being so low in the cabinet. I've had the fantasy of putting a second mid bass coupler near the top of the baffle. Since Braun made a 4 ohm version, it would be pretty easy to wire them without changing the crossovers.

    It's worth noting that Bill Watkins considered the cabinet of the QLS-1 to be too large to get the best out of his woofers. He preferred the Q-3 cabinet size. Bill Jr. once told me that his father had suggested to Arnie Nudell that the QLS-1 cabinet should have a baffle inside it to make the box smaller. We know that Arnie used smaller woofer enclosures with tall baffles for the mids and tweeters on his RS series.

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