Philips AD12100/M8 in open baffle

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Some weeks ago I bought a pair of vintage Philips AD12100/W4 from another DIY/er who needed to clear his huge collection. I intended to give these a try in a TL of some sort. To my surprise he sent me 4pc ... so the plan changed to an OB with 2 of these per side, with the lower of the 2 only used for the lower frequencies.

I had suitable piece of wood laying around (an old table), so I cut that in half, made the holes with my router, added triangles on the side zo it would a) be able to stand up and b) create a sort of U-frame for the lower driver to have a bit more bass:
attachment.php

attachment.php

After having this one completed, I hooked it up to my Marantz 2230, adjusted bass and high a bit with the tone controls and played some music...
which was a positive surprise, this already sounded rather nice, especially voices. and that in mono...

After that I fired up my microphone and did some measurements:
attachment.php

purple curve is lower driver (measured off axis), beige curve is upper driver (on axis, 1m)

I loaded the measurements into LspCAD to do some filter simulations. The lower speaker I just add a 15mH coil, the upper got 2 corrections for baffle step & dipole loss compensation (and in the process, the highs got a boost as well):
attachment.php

attachment.php


Looks promising... now just need to build the 2nd speaker and solder the filters and then have a proper listen. I hope to have time for that in about a week...
 

Attachments

  • OOOB  voorkant.jpg
    OOOB voorkant.jpg
    102.3 KB · Views: 2,866
  • OOOB  achterkant.jpg
    OOOB achterkant.jpg
    117 KB · Views: 2,608
  • on axis @1m.png
    on axis @1m.png
    13.5 KB · Views: 2,183
  • OOOB gefilterd (simulatie).png
    OOOB gefilterd (simulatie).png
    27.3 KB · Views: 2,550
  • OOOB - filterschema bovenste.png
    OOOB - filterschema bovenste.png
    4.8 KB · Views: 2,342
Hi HenkJan,

I really love the vintage Philips drivers. I had the AD12100 in a semi open baffle (combination with AD12200W in BR). Later I swapped the AD12100 for the AD12202.

After that I left the OB design for a single AD12202 in a BR design. This is nice but not as nice as the lovely open sound of the OB design.

I just know you are going to have fun with the stereo pair..

Probaly you know this already but a wider baffle gives more bass. I went from 38 cm to 60 cm and later added sides to them with great success. I don't have measurements unfortunatly.

Good luck on your build! Does your fellow diy-er has any Philips drivers left?

R.
 
attachment.php

... now just need to build the 2nd speaker and solder the filters and then have a proper listen.
so, build is complete and had proper time to listen the past week. Long story short: these things are amazing, I never experienced the 'illusion' of having the musicians in my room that realistic as with these 12"s. And they handle every kind of music with ease, not just our standard audiophile small combo, but also rock or orchestral classical music sounds great.
 

Attachments

  • OOOB - vintage spoel .jpg
    OOOB - vintage spoel .jpg
    148.4 KB · Views: 231
  • OOOB - logo .jpg
    OOOB - logo .jpg
    181.4 KB · Views: 224
  • OOOB - klaar om te luisteren.jpg
    OOOB - klaar om te luisteren.jpg
    194.3 KB · Views: 1,888
  • OOOB - achterkant met filter en tweeter .jpg
    OOOB - achterkant met filter en tweeter .jpg
    212.7 KB · Views: 271
  • OOOB - USSR verdeelpunt.jpg
    OOOB - USSR verdeelpunt.jpg
    242.7 KB · Views: 302
you mean so that the axis of L & R cross in front of the listener? I'll give it a try

(iirc this was also recommended by Jordan for some of the designs for the 92)

Yes, exactly, see page six in the 1966 brochure as linked to here: Philips overige

(funny, how these speaker designs were specifically integrated with the "doorzonwoning" of the day... The house of the future!)
 
After listening at a fried's, I changed the correction a little bit to raise the upper midrange 1 or 2 dB (I made a switch). I did not have the time to listen to the result yet

btw: if anyone wants a listen, I'll be bringing these to this saturday's "Luisterdag" in Breda (see the zelfbouwaudio.nl forum)
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.