Philips AD12100/M8 in open baffle

[Henkjan]

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:

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:

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):

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...

 

[Xerxes75]

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.

 

[Henkjan]

thanks.

He sold most of his drivers, but I see he is collecting again... are you looking for anything in particular?

 

[Squeak]

Have you tried running them straight, I.E. filterless?

 

[Henkjan]

yes, during run-in. lack of bass naturally due to the dipole-loss, but otherwise surprisingly well behaved, could do with more highs, but voices sound superb.

 

[Aad]

Did you mix R1022 and R1021 in the image?

 

[Henkjan]

R1022 represents the Rdc of the coil

 

[Henkjan]

... 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.

 

[Lohengrimas]

Nice build! Have you tried putting them in a "Philips" set up, as mentioned in the old manuals? (i.e. 45 degree toe in to get a truly wide sweet spot).

 

[Henkjan]

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)

 

[Lohengrimas]

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!)

 

[Henkjan]

great link! thanks

 

[Henkjan]

Nice build! Have you tried putting them in a "Philips" set up, as mentioned in the old manuals? (i.e. 45 degree toe in to get a truly wide sweet spot).

that was a fast experiment: not a success, too much loss in highs. so they remain 1 person speakers

 

[Henkjan]

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)

 

[Aad]

btw: if anyone wants a listen, I'll be bringing these to this saturday's "Luisterdag" in Breda (see the zelfbouwaudio.nl forum)

Count me in

 

[Henkjan]

Count me in

looking forward to it