Forum Top Banner Ad

Collapse

Ebay Classic organs

Collapse

Announcement

Collapse
No announcement yet.

750hz High Pass Filter Design for a Leslie Speaker

Collapse
This topic is closed.
X
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • 750hz High Pass Filter Design for a Leslie Speaker

    Having found Tony Trouts video of his 750hz High Pass Filter (02:48) https://youtu.be/4AjviQVsTds?t=168

    Is there anybody on this site who can advise me on such a filter design as Tony wants to protect his IPR and sound.

    Many thanks in advance.
    Neil Jenson 'Connoisseur' 3/35 VTPO. Gulbransen Rialto II.
    Building a full set of WERSI W3 voice filters and designing new Hammond X-66 voice filters for a new MIDI controlled organ.
    Various Leslie speaker projects including 'Rotosonic' L102, L103, L212S and building a new L122 cabinet.

  • #2
    These days, many people use the various crossover calculators you can find via Google to design basic crossovers.

    Since this is specifically noted as being a high-pass filter (high-pass only) and it uses two capacitors and one inductor, I would conclude that it's a 3rd order crossover, used, in this application, to provide a pretty steep rolloff of bass frequencies to protect the horn driver. Looks like he chose the closest standard component values for the circuit. One looks like a 60uF capacitor, but I can't be 100% sure.

    Steep crossovers like 3rd order and higher are sometimes needed in high-power speaker systems to protect the high-frequency drivers from damage from lower frequencies.

    Like I often tell people, designing basic crossovers is not rocket science. It gets complicated in high-end, high-fidelity speakers where much more complicated calculations go into maintaining phase coherence and smooth frequency response, taking into account the Thiele-Small parameters of the drivers. With a Leslie, you're not building a HiFi speaker, so these concerns are not particularly relevant.

    From what I can gather from what the builder says, I don't think any low-pass filtering is being used for the woofer. In some speakers, the woofer is allowed to run full-range with only its inherent lack of high frequency response limiting its output. That does mean you're heating the coil with frequencies it can't reproduce, but I guess it works here.

    You generally don't see knowledgeable speaker builders using fiberglass anymore for acoustic damping. Polyfill replaced it years ago.

    If you want to copy it, it's up to you.
    I'm David. 'Dave' is someone else's name.

    Comment


    • #3
      Thanks for the tip David, I never knew such calculators existed! :-P

      Using the website https://www.diyaudioandvideo.com/Cal...akerCrossover/ I got this result, so sorted for the moment.

      Click image for larger version

Name:	3rd Order 750hz.png
Views:	1
Size:	16.5 KB
ID:	606844
      Neil Jenson 'Connoisseur' 3/35 VTPO. Gulbransen Rialto II.
      Building a full set of WERSI W3 voice filters and designing new Hammond X-66 voice filters for a new MIDI controlled organ.
      Various Leslie speaker projects including 'Rotosonic' L102, L103, L212S and building a new L122 cabinet.

      Comment

      Working...
      X