John Reekie
Technologicality, at work and play

SB29RDC on Pellegrene waveguide

In the original Convertible proposal, I wanted to use a waveguide on the tweeter. Towards to that end, I’ve now bought a pair of SB Acoustics SB29RDC from Dan Archer and suitable waveguides from Dave Pellegrene. (I also have another project in mind for the SB29/waveguide combo, which is a larger speaker using a high efficiency 6″ midrange.)

To mount the waveguide, you remove the three screws from the tweeter faceplate, insert the provided studs into the tweeter, and use the provided nuts and washers to bolt on the waveguide.


With a very quick and rough measurement, with the tweeter held by hand about 15cm away from the microphone, here’s the tweeter with the standard faceplate, at 0, 30, 60 and 90 degrees (ignore vertical scale except for relative reference):

And here it is mounted in the waveguide:

So that looks very promising!





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Readers' comments

    hi John…how very interesting!…I’ve just purchased the SB acoustics TW29R Satori tweeter and MW16P midwoofer duo and had originally planned to mount the TW29R on a flat baffle…HOWEVER i’m really addicted to my present waveguide (purpose built by Jantzen for the Audax TWO34 34mm soft dome), this is a really solid item beautifully milled out of hard black plastic billet and I’m currently using it with that same tweeter in a two way design crossing over at ca. 2600 Hz…

    the sound is so realistic (i only listen to FM Radio 3) that with really good live programme material it can sometimes startle me into momentarily believing that vocalists are actually right there in my listening room!…high pianoforte notes are delivered with a clarity, attack and dynamism which is equally stunning…stringed instruments, woodwinds, brass too all have a realistic ‘bite’, attack, rasp and clarity of tone and vibrato that i have only experienced at live recitals!

    i had originally planned to sell my waveguides together with the tweeter when i replace the TWO34 which is partnering an Audax HM170Z18 HDA 6 1/2″ midwoofer at the moment…reason: the waveguide has an aperture dia. of some 44mm which is far too large for nominally 1″ tweeters…imagine my surprise when i unpacked the Satori tweeter and measured it as also having an aperture dia. of 44mm!

    if you google ‘SB Acoustics on waveguides’ – and scroll down a bit – a pdf comes up which details the offsets from a variety of SB drivers, including the TW29R + MW16P combo…there they recommend a total WG depth of 21mm from baffle to tweeter mounting surface…okay, here the fairy story ends as in the TWO34 WG that same dimension is 28mm…

    however – notwithstanding that 7mm difference – i’m still intrigued by the thought that my waveguide + TW29R might still give the same kind of clarity and realism i am enjoying right now with the much older Audax design given that this 34mm unit is limited to 14 – 15 Kz max…

    i have already sent a message to SB on their official website over a week ago asking if it’s possible to remove the faceplate for flush mounting behind a WG but it has simply been ignored!

    that’s why it’s great to find someone who has already done this with a similar SB tweeter!…what i cannot see from your pics is where the studs protrude behind the Pellegrene WG’s to be secured with the nuts?…i definitely could not do this with my present WG as it’s very thick and solid, however i COULD have a NS4 alu faceplate made up (say 2mm thick) with 44mm aperture and the same outer dia. as the present faceplate and then use this as a template to drill out the 3 mounting holes – securing the new faceplate to the tweeter body with c/s machine screws…then the new faceplate can simply be attached by screwing into the hard plastic of the WG with self tappers (as the present TWO34 is fixed)…

    i would really value your comments…btw. i’m using a purpose built x-over designed by Geoff Bagby for his Kairos 2 way design using the same drivers, the x-over frequency is 1800Hz

    kind regards brian

  • PS: forgot to mention this…given the glowing praise for my present system, the obvious question is: WHY do i need to make any changes?…the answer lies in one word, namely cymbals…the TWO34 can’t reproduce a cymbal to save it’s life!…the true, lifelike sound with it’s overtones and decay simply comes over as a flat, bland wodge of smeared and blurred preudo sound…that’s been my Holy Grail for a long time now, to build a system capable of more faithfully approaching the real cymbal sound…that’s why i got excited when i read this in Geoff’s summary of how his Kairos’ sounds:

    “The high frequency reproduction of the TW29R is pristine. Cymbals are resolved with almost life-like clarity that leaves most other speakers sounding lifeless and plastic. You do not hear the muddied splashiness associated with so many other tweeters due to their distortion. Triangles and hats both sound extremely clean and sharp, the sonic edges are very crisp, and when listening to jazz being carried by a ride cymbal I feel I am almost transported to the room the musicians are in”

    hope i did everything correctly by clicking on the link to confirm the original message…

    kind regards brian

  • Hi!!! How can I get a pair of those waveguides?? I will really appreciate your help on that matter…

    • Hi Julio, Dave Pellegrene seems to not be making them any more. You could try the Visaton WG148R or the diysoundgroup SEAS-8 as possible alternatives. (Don’t have either of them myself yet.)

    I too am looking for a waveguide for SB Acoustics SB29RDC-C000.

    I tried the Visaton WG148R and the throat is a little small, it interferes with the tweeter surround.

    Any suggestions?


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