Please review the site Rules, Terms of Service, and Privacy Policy at your convenience. Rules, TOS, Privacy
Get familiar with the reaction system: Introducing the Reaction System

Bring back the L-pad ?

edited January 18 in DIY

Vintage speaker designs, such as JBLs, encorporated L-pad designs to provide user integration into a specific room environment / preference.  

Been playing around with a contour circuit (coil with parallel adjustable resistor, aka one path of L-pad).  The full adjustment range is ~3dB, the pic is at approx 1/3rd and 2/3rd rotations.  


  • I have been thinking of using an L-pad so I can bump up my tweeter level when I demo my speakers and drop it back down for late night listening sessions.
  • I set up my crossovers for a "neutral" response, and any tuning beyond that is easily done externally via EQ. The advanced parametric EQ solutions available these days negate any need for passive crossover user adjustments.
    I'm not deaf, I'm just not listening.
  • dcibel,
    Yes I agree.  I use a miniDSP to both bi-amp and eq (parametric) my speakers.  The pic is of a litt'l AN4in. broad-range driver I use with a 300Hz high-pass filter.  Once set up as 'neutral' (~flat, with a slight tapering off) I was thinking of just having the L-pad on the drivers...
  • I used to tweak on the hot side for MWAF and got burned last year.  I'm back to normal/ neutral and cursing bad recordings.
     John H, thanks to JP I did get that email
  • Wow, when I saw the title of this thread the first thought that popped into my head was:  L-pads, Zobel networks, Speaker Builder 201, WinISD, etc.   =)
  • I have never changed my voicing for MWAF, and really don't understand why others do so. Chuck pulled the top-end down on his MTMs last year, and I thought they sounded dead/dull at InDIYana. I took the Zingers over there last year, and compared the voicing. He told me that's what he did, and I don't really understand why. Dull at home is dull everywhere, IMO.
  • edited January 19
    The room / the sound enviroment, can and does have significant impact / effect - 
    thinking of a downtown appartment with floor to ceiling windows vs my listening/ living room...

    Wolf, I agree in that at these speaker-offs often (to me anyway) it comes down to the integration of the tweeter; just right, too muddled or too bright.  With the contour circuit (using L-pad for its varialble resistance across an inductor) vs. using the L-pad as a level control provides a controled tilt (as opposed to raising and lowering the whole driver, which can cause issues at the crossover). 
  • I used to tweak on the hot side for MWAF and got burned last year.  I'm back to normal/ neutral and cursing bad recordings.
    I have 3 torture tests for builds:  Mozart's Requiem for massed voices, Yello for pumping bass, and Bonnie Raitt for her seemingly inherent sibilance. If I can nail all 3 I'm done with the build.

    Don, Donno, or "Hey you" all work for me, But never "Mr Johnson"
  • Yeah, I've got hours of music.  My latest mistakes have been vertical off axis.  Goofy baffle shapes are a learning experience.
     John H, thanks to JP I did get that email
Sign In or Register to comment.