High-performance, high bandwidth lightweight 1D diffuser.



Optiffuser on rear wall in LEDE control room


For detailed information; please see the manual:

Optiffuser Manual



Suggested retail price of the Optiffuser (pack of 4 panels) in Sweden is 2800 SEK (including 25% VAT) and can be purchased from:




The pricing of the Optiffuser outside of Sweden (within the EU) including shipping, excluding VAT, is dependent on quantity and delivery options:

1 – 2 packs = 300 € / pack*.  Delivered as single packages.

3 – 5 packs = 265 € / pack**.  Delivered on pallet.

6 – 8 packs = 240 € / pack**.  Delivered on pallet.


* The drop-off needs to be accessible with a small truck. Receiver needs to be on site at time of delivery.

** Delivered on pallet and the receiver needs to be able to unload the pallet from a truck (either via dock or with a forklift). The drop-off needs to be accessible with a big truck. Receiver needs to be on site at time of delivery. If this requirement cannot be fulfilled, the product needs to be shipped as single packages and the price is 300 € / pack regardless of quantity.


17 thoughts on “Optiffuser”

  1. Dear Jens,

    I saw on GS that you sold some optiffusers to another member. Is there a online store somewhere or do you only sell directly? If so, what the price????

    PS: they need to be shipped to holland, and I probably will need 8 of them.


    1. Hi Lars and thank you for your interest in the Optiffuser.

      In Sweden, I only sell direct to clients of mine. Others are directed to the two stores currently selling these:
      Emusic (www.emusic.se) and 4sound Stockholm (www.4soundstockholm.se)

      If outside Sweden, I’ve so far sold direct but this might change soon. Check my mail for further details.

      Sincerely Jens Eklund
      Resonator Stockholm AB

  2. Hello,

    Congratulation for your work on this diffusor. I’m interested by the optiffusor. Could you send it to France at what cost.

    Thanks to reply


    1. Hi Philippe

      Thank you for your interest in the Optiffuser. The prices found above include shipping (within the EU). Feel free to contact me if you have further questions.

      Sincerely Jens Eklund

  3. Hi, I live in the US and am interested in your Optifusser. Can you give me a price for one pack, including shipping to Colorado, zip 80027? How much wall surface area is covered by one pack? Thanks!

  4. Hi Jeff

    One pack of Optiffusers (4 panels; 1,2 x 0,6 m each) will cover 2,88 m² (31 square feet). I think shipping for a single pack will be costly relative to the price of the actual product, but I´ll see if I can get a quote for shipping of a single pack. I´ll get back to you via mail.

    Sincerely Jens Eklund

  5. Jens,

    What is your recommended as well as the absolute minimum listening distance away from these diffusers?


    1. Short answer:

      At least about 1 – 1,5 meters but if that close, you´ll naturally still get high gain (relative to direct sound) early reflections; something normally not considered a good thing even if diffused (although there are some controversial HiFi concepts that proclaim this is a positive thing).

      Long answer:

      In order to advise on placement of acoustic treatment and diffusers in particular, one first needs to decide what acoustic response (speaker-listener response primarily, but environment response might also be important) we are trying to accomplish in the room. Assuming a studio control room; the more common options are: LEDE/RFZ (or possibly CID), NE (or any of the variants of it) or perhaps “Ambechoic” if surround formats are important (or at least something similar to it; like a LEDE/RFZ but no termination of the ISD-gap but still featuring a “decay time” of about 0,3 seconds by a highly diffused sound fled). Common for all above mentioned control room design concepts is that they try to avoid strong early reflections that otherwise deteriorate the accuracy of the reproduction (comb filter artifacts, image shifts etc).

      If hi-fi listening room (not critical listening), there are no rights or wrongs, but I would still personally try to at least avoid early strong reflections and try to create some kind of diffuse return (after a certain time frame, at least about 12 ms or so, preferably longer) to the listening position in order to keep some life in the room instead of ending up with a “dead” sounding space (unless this is what is requested naturally). The criteria’s of LEDE/RFZ would be my first choice, or perhaps something in-between LEDE/RFZ and Ambechoic (a proper termination, no termination, or limited termination of the ISD-gap assuming highly diffuse decaying sound field). Also, since we´re talking about placement of diffusers, NE design is probably not of much interest, especially for normal listening rooms since this approach tries to achieve an anechoic speaker-room response although one can use diffusers even if NE in order to keep the general room response somewhat alive (but without scattering too much speaker energy to the sweet spot thus deteriorating the anechoic speaker-listener response).

      Assuming we strive for a LEDE/RFZ (or possibly CID) response, we first need to select an ISD-gap and this is either done by simply measuring the room and identifying the first order reflection from the rear wall, or calculating the time difference between the direct sound and the reflection from the rear wall based on the geometry, and then deciding if this is an appropriate ISD-gap (between about 12-25 ms). If the control room is connected to a large recording room, the live room usually dictates the ISD-gap needed in the control room. Preferably, the ISD-gap in the control room needs to be at least about 3-5 ms longer than the recording rooms generic ISD-gap). If the distance to the rear wall in the control room is too short to provide a sufficient ISD-gap, treatment and/or geometry can be used to extend the natural ISD-gap of the room (by using absorption and/or splayed walls on the first reflection point on the rear wall and using rotated 1D diffusers on side walls for instance).

      If a less strict treatment is requested, then at least try to avoid placing diffusing elements in such a way that they scatter early energy back to the listening position within about 10-12 ms or earlier compared to the direct sound. I would personally try to extend this period to at least about 15-17 ms, 20-25 ms if possible (a longer ISD-gap allows you to hear the acoustical footprint of the recording easier, especially of larger recording rooms). Use geometry and/or absorption to redirect/absorb early energy away from the listening position that would otherwise arrive too soon (within the desired ISD-gap).

      If absorption is used, make sure to use thick panels so that you don´t simply “EQ” the reflections, only removing the high midrange and highs from it, leaving the low mids and bass frequency range unaffected. Use at least 120 mm, preferably 200-300 mm or deeper (and make sure to use a wool with appropriate flow resistivity for the given depth). Only use broadband absorption where needed, or you´ll struggle to keep the energy needed to keep the room “alive” (in order to reach the desired gain of the ISD-gap termination).

      Use the ETC to track down your early reflections and figure out what areas needs attention. Also, remember that diffusers also absorb energy more or less. One cannot “add” energy to a room by adding diffusers unless they are substituting treatment that absorbs more than the diffuser replacing it. Simply adding diffusers to a room does not automatically make it sound “more spacious”, it´s the combination of all treatment in a well thought out design that achieves this; the ISD-gap and the termination of it in particular.

      The energy return (the termination of the ISD-gap) should arrive primarily from the rear sides in a LEDE/RFZ/CID room and this is the reason why you normally see 1D diffusers on the rear wall in such rooms. As stated above, if your room is too short to provide a sufficient ISD-gap using the rear wall, one can extend this gap by various treatment options but assuming the room is not too short (or too long); the rear wall is the most efficient place to put 1D diffusers, since they will scatter the sound to the sides and then back to the listener via the rear side walls.

      Assuming one understands that diffusers also absorbs energy (more or less) and that we are now probably striving away from LEDE/RFZ and moving towards the Ambechoic response; one can add diffusers to other surfaces as well as long as they don’t (partially) scatter energy back to the sweet spot within the ISD-gap (with or without termination).

      A note on low frequency treatment (modes and SBIR related issues): I recommend pressure based absorbers for the bass region for two reasons: First, they don´t need to be ridiculously deep in order to be effective at low frequencies and secondly, they don´t absorb the upper range that one usually struggle to preserve in order to achieve a proper termination of the ISD-gap and the semi diffuse field that should follow it (assuming LEDE/RFZ/CID design or Ambechoic with decent “decay times”).

      For proper use of any acoustic treatment; measure and analyze your room and decide on a response model to use as a guide when deciding on different treatment options. I know this might sound daunting, but the alternative is usually a less than perfect outcome but if you´re happy with that: build/buy some panels and fire away!

      Sincerely Jens Eklund

  6. Hi there, I completely agree with the intent and engineered product behind the optiffusor panel.

    I am currently speccing a difficult public venue install in premises with hard concrete surfaces and I would like to order a bunch of the panels.

    What is the production and delivery lead time to London?

  7. Hello Jens,

    Just ordered 1 pack optiffusers from emusic to ship to the Netherlands. Specs of the optiffusers made me very curious.

    I do have a question though. You advise to glue the optiffusers to the wall (or in some cases use an airgap).
    I don’t like glueing, because it prohibits change in the listeningroom.
    How do you feel about two screws in the wall, and two little holes in the backside of the optiffuser? Could the weight (max 6kg if painted) be a problem for the structure of the eps/optiffuser, and therefore rip or break?

    Could pritt poster buddies also be an option (http://www.hornbach.nl/shop/PRITT-Posterbuddies/7905175/artikel.html?origin=%7Badtype%7D&WT.mc_id=nl14a999&WT.srch=1)?
    My current eps diffusers ( size 60x60x7) are hung this way, but these are 20kg/m2 eps diffusers. Only needed 4 pritt poster buddies in the corners and none of the eps diffusers have fallen yet.

    Greetings, Erik

  8. Hi Jens,

    We are opening a new cafe/bar/music venue this Saturday is there any chance you use a shipping service that would deliver the product to London by Friday?

    Thanks a lot and have a lovely day,

  9. Hi Jens,

    I read the whole manual and all Questions asked here at least twice.
    But i still have a understanding problem:

    In which angle should I place the optiffuser?
    should the “stripes” horizontal or vertical from my viewpoint?

    is it ok to mount nearly the whole ceiling with of my listing place with optifusers?
    i read in thoose questions here that u recommend to mount it on the back. Sooooo – should i mount it there too ?
    I have a window at my back and wanted to cover that with a molton curtain till now, but i realy realy are worried about getting a “dead sound room” of absorbing all “high’s” away, throught i wanted to place a high pile/long pile carpet at the whole floor and this would absorb 2.
    The last thing i wanted to do is to place absorber at the first reflecting spots and put 50x50cm corner absorbers (wool) in each corner. Throught its only 3 corners, cause my listening room is like a L-shape.

    And cause of the L-shape. I wanted also to mount the 1 REAL-side wall with optiffusers 2.

    as i understand it, it would be smart to paint the optiffuser, right?
    as i read the grafic about it first, i thought:
    why should anybody do this and loose absorption?
    but now i think:
    maybe i definatly should paint it – cause i will get waaaaaay to mutch absorption with thoose mutch area of optiffusers and will end up in a “dead room”
    can u agree with that?
    it also should be better to protect the optiffuser right? without painting it should age way faster cause of the sunlight e.g., right?

    this all in mind:
    can u please please please help me and tell me on which wall/walls i should mount the optiffusers?
    &… i which angle i should mount them?

    i diddnt even got the thing with that positive A-B and negative B-A mount sequence. cause i dont get the difference of a positive A-type to the negative B-type. Arent they just the same?

    i realy wrote mutch, sry.
    But i finally realy wanna have a listening room i am happy with and it seems, u have realy amazing knowledge about it.
    and i realy realy hope u can / or better sad: u want to help me.
    and while i am on it:
    i searched the whole internet for a quite sheep, but still good and effective diffusor and for real:
    i diddnt even found any option except yours!
    I realy realy hope your product will be that good as it seems to be in the manual. Then – it will be BONKERS! 😀

    thank you very very mutch & i hope u can find the time to answer a question of someone who finally wants to hear music in an awsome way, with the help of your gorgeous product!!!!!
    THANKS! 🙂

    1. Hi Christoph

      Hopefully I´m a better acoustician than web page admin 😉

      Many questions, and it would be better (quicker) I think to address them by phone (see my mail). I might try to expand on previous post, explaining in more depth how to think about diffusion in different situations, sometime in the future if time permits. To update the manual has been on my to-do-list for a long time but it´s not a high priority at the moment.

      Talk to you soon.


  10. A lot of time has passed since 2017. xD
    But…. finally…. my new home will be finished building.

    So… i still want to have Diffusors with kind of absorption rate and i realy think yours are great! 🙂
    I still think only integrating your diffusors 360° would be perfect… they have some kind of absorption rate if i dont paint them, which i dont plan to do.

    if i take 8 of them… is there a possibility to reduce the price a bit more then the 240€ each which you “standartly” offer? 😀
    i realy have to pay a huge price for the bass absorbers -> they will kill me xD

    there sure is a bit of price correction tollerance, right? 😀

    none the less:
    do you think placing your diffusors 360° in my home cinema is a good idea?
    i want to combine them with bass traps… should be enought right? 🙂

  11. a lot of time has passed..

    long story short:
    my house is finished in 2 month & and i think it will be the best to surround my whole cinema with your diffusors… right? 🙂

    is it possible to give a discount maybe?
    more than the one normally available?
    because – i realy need to buy a lot of them 😀

    everything else -> maybe we talk privately? 🙂

  12. Hi Christoph

    I normally don’t recommend going crazy with diffusers but rather focus on the relevant areas Normally rear wall if stereo, but possibly other areas if surround is the main focus of the space.

    Give me a call and we can discuss your situation in greater detail.


    1. I finally got my housing now!

      finally i can create my cinema.
      I realy thought 360° Optifussers should do the work, in addition to “bass traps” in the corners….

      i will call you more often this week.
      Hope u can help me to find a (maybe) better solution & MAYBE a discount on such a big order is possible too 🙂

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.