Open Source Monkey Box

Last edited:
... What about the Faital HF108?
Together with a suitable horn it should be one of the better options available. Only need to pad it down a little. Distortion figures should be ridiculously low since you only need a fraction of a watt to get really loud.

Edit:
And the Faital 6PR150 looks nice enough from ca 400hz up? has high qms too. How about an all Faital build? It would probably make it easier for people to order parts too, all from the same place.

I apologize for increasing the potential of confusion.
 
Last edited:
Copied from the open source waveguide thread:

Well, as you ask... <snip>

The Bliesma tweeters look very nice!

However, the Volt VM752 starts beaming a bit earlier than most 3" drivers, see audioXpress measurements, 3 dB down at 2.5kHz/30 deg. The Bliesma is nearly at full level at this point, so not a good match in terms of directivity. I am still thinking of waveguides...
 
Last edited:
They are all same (outter circumference of the surround), 6600, 7000, 7100, I had all of them physically mounted in WG148R and my WG.
R2004 and D2004 need 29-30mm, and again, they are same.

R 7000 in WG measurement is in the attachment, it is WG170mm, prototype, profile is not exactly what it should be as carpenter sanded too much. I should have new prototypes soon. Anyway, I hope it shows some potential for your application and development of your WG.

Pida> this is a ring radiator you're referring too? I have a hunch they are smaller diameter than the domes?
 

Attachments

  • SS700 H 0-90 and DI no crossover.png
    SS700 H 0-90 and DI no crossover.png
    69 KB · Views: 461
Last edited:
Measurement conditions:
- drive voltage not specified, I estimate ~2V
- mic distance 1m
- gatting window 3.6ms
- no smoothing
- measured in cabinet in the attachment, 220x460mm

To mount these scanspeaks to WG you have to remove the faceplate and make the saddle for tweeter which also centers it.
 

Attachments

  • 20180714_144613.jpg
    20180714_144613.jpg
    610.4 KB · Views: 481
  • WG148R mod for SS7100.PDF
    37.6 KB · Views: 149
38mm throat diameter for R3xxx and D3xxx family (and R29xx) = 1" domes and ring radiators (6600, 7000, 7100) 29-30mm for R2xxx and D2xxx family = 0.75" domes and ring radiator (D2004/6020, R2004/6020)

Pida> You mentioned 38mm and 29-30mm, which is correct? 30mm would be promising. The 6600 family is not that small is it?
 
Last edited:
Measurement conditions:
- drive voltage not specified, I estimate ~2V
- mic distance 1m
- gatting window 3.6ms
- no smoothing
- measured in cabinet in the attachment, 220x460mm

To mount these scanspeaks to WG you have to remove the faceplate and make the saddle for tweeter which also centers it.
Ok, thats a bit more involved than the simple kitchen table approach that we have in mind to make the Monkey Coffin "novice friendly". But maybe the WG148 can be adapted to the Scan using easier tools, a bit like what I did here using the Monacor WG300. If a custom 3D printed waveguide is possible, that might be best.

How deep should the waveguide be? Would it make sense to align the voice coils of the tweeter and the midrange?
 
If the result of tweeter/WG combo is close to constant directivity, and dispersion is same for the midrange at crossover frequency, in that case I found LR4/LR4 more suitable. It results in almost perfect power response (based on horizontal measurement). Of course, when vertical response is included into equation, power response and DI have dip/bump at the crossover frequency.

For XT25 in WG300 + P17RCY I used LR2/LR2 which created smooth mid to tweeter transition, but for this combo DI is monotonically rising.

In both cases it is benefical to have tweeter acoustic center roughly aligned with midrange. It makes crossover modelling and obtaining good phase tracking easier.

How deep should the waveguide be? Would it make sense to align the voice coils of the tweeter and the midrange?
 
mbrennwa> it would be best to have one in-hand so I can make sure the design fits
Ok, here's how I see this... D.A.S. and Faital woofers and Volt VM752 mids are all ordered. Once I have them, I will do various measurements (as described in an earlier post). The directivity of the VM752 will tell us how to match the tweeter. If these data still show the same directivity as the aX measurements (I would be surprised if they didn't), we can go ahead an design a suitable waveguide/tweeter combination. Otherwise the Satori tweeter as in Pauls simulation study seems a good choice to me.

What do you guys think?