Philips 9750/M Help plans cabinet

[Stanco]

Hello,
I received two wonderful speakers Philips 9750 / M. I would bring them back to life by building an enclosure suitable to them. Only you can help me ... Maybe simple.... example bass reflex (audio nirvana docet), or MLTL .... I do not know ... give me suggestions ...
Forgive my bad English
Marco

 

[DrBoar]

Philips 9750
I would try a simple open baffle. If they sound OK on axis and you want to play louder a closed box perhaps. For bass reflex you need to be able to measure T/S parameters to get a resonable design (that or a lot of trial and error...)

 

[Stanco]

DrBoar hello, thanks for your reply. the dipole is too big for my room. These are the specifications found on the net:

Diameter 8,5 inch (21,5 cm) - Deep 5,2 inch (121 mm) Impedance : 5 ohm



AD 9750 M

20-60-AH


===========================================
Philips specs:

8 inch luidspreker from 1952 with hig efficiency

Produktcode : 49 239 51 - 20 60 AH

Philips 9750M with double wizzar 18.000 Hz

The magnet is 13.000 Gauss / 58.300 Maxwell

Efficiency : 10%

Imp: 5 ohm

P diss: 6

Res: 60 Hz

Freq: 18.000

Size: 21,6 x 21.6 x 12,1

Weight : 1700 gram Specs

===========================================


Specs from the internet :

8.5" Overall Diameter
4.76" Tall
5 Ohm
Response rated up to 20,000 Hz
13,000 Gauss / 15,300 Maxwells
10% Efficiency (approximate equivalent of 102dB)

Re.....................4.2814 Ohms
Fs...........................69.98 Hz
Qts..............................0.532
Qes.............................0.561
Qms.............................10.24
Le.....................0.25mH (10k)
Mms.....................9.412 grams
Vas........1.453 ft^3 (41.14 liters)


if it is accurate, I do not know.

 

[Stanco]

the cabinet audio nirvana created by David Dicks not and does not wish to follow the concepts T / S and it seems that the same sound good ... ��

 

[GM]

Specs from the internet :

Greets!

Based on these specs, a 152 cm tall x 870 cm^2 MLTL [~132 L] with a 56 cm driver offset [~seated ear height for many folks] and a 248 cm^2 baffle thickness vent down at the bottom looks good for a flat mid 40s tuning, good enough for most music at a reasonable SPL with a few watts. If up against a wall, then add vent damping as required. [all dimensions i.d.].

GM

 

[knarfor]

Specs from the internet :

8.5" Overall Diameter
4.76" Tall
5 Ohm
Response rated up to 20,000 Hz
13,000 Gauss / 15,300 Maxwells
10% Efficiency (approximate equivalent of 102dB)

Re.....................4.2814 Ohms
Fs...........................69.98 Hz
Qts..............................0.532
Qes.............................0.561
Qms.............................10.24
Le.....................0.25mH (10k)
Mms.....................9.412 grams
Vas........1.453 ft^3 (41.14 liters)


if it is accurate, I do not know.

Those are my specs! I posted those to an eBay auction. That looks like the information from a NOS unit I sold a long while back.

These are my measurements for a used pair I also sold:

Re.....................4.645 Ohms
Fs.....................57.2 Hz
Qts...................0.581
Qes...................0.617
Qms..................9.976
Le.....................0.245mH (10k)
Mms..................11.66 grams
Vas....................49.71 liters

 

[GM]

Cool, the MLTL still works, though with the lower Fs, some may want to tune it a little lower with a longer vent.

GM

 

[DrBoar]

Those T/S parameters look pretty good. Start with a simple box and find out if the mid and high range qualies warrant a more elaborate effort.

 

[knarfor]

I have an FR plot for these around somewhere...

 

[knarfor]

The plot is at 10dB per division.

If I remember correctly, the huge suck-out at 5.5K is caused in part by cancellation between the whizzer and cone. It can me mitigated somewhat by inserting foam between the whizzer and main cone, like Rutcho did here.

 

[DrBoar]

The FR looks better than the 9710!
I would build a large box 50-100 L with two or three bass reflex vents and having plugs for the vents so they can be tuned differently or even converted to closed box. A whide baffle to help the level below 500 Hz up in output. It also adds to the vintage look...

 

[knarfor]

The FR looks better than the 9710!
I would build a large box 50-100 L with two or three bass reflex vents and having plugs for the vents so they can be tuned differently or even converted to closed box. A whide baffle to help the level below 500 Hz up in output. It also adds to the vintage look...

I liked the 9750M a bit better than the 9710M. I compared them side by side, as well as in a back loaded horn.

 

[Stanco]

Hi guys, thanks for the measured parameters. But here it needs a construction plan suitable to these beauties. maybe not too big or difficult or more expensive ... I ask too much? 🙂 maybe yes...

 

[Stanco]

perhaps, it sounds good in a Jensen ultraflex.
or in this cabinet on diyaudio homemade presented by our friend VVXUAN.
carry the link of the discussion:
http://www.diyaudio.com/forums/full...mples-box-very-good-full-range-speaker-6.html
or you have to build something similar to the bass reflex cabinet proposed by audio nirvana ... you have your say.

 

[GM]

But here it needs a construction plan suitable to these beauties.

http://www.diyaudio.com/forums/full-range/280522-philips-9750-m-help-plans-cabinet.html#post4472247

GM

 

[Stanco]

hello GM you're right ... I do not know why I had missed ... you can have a design, a plan, to see exactly what you thought. how you calculated these measures?

 

[GM]

Greets!

If you are asking for a drawing, I do not have one, just the information I posted, which is enough for you to build it, though you will have to decide what the width, depth is for the 870 cm^2 i.d. area and where to put the 248 cm^2 [17.77 cm dia.] vent.

If I built it, I would use the golden ratio 1:1.618.........width = 37.52 cm, depth = 23.19 cm and the vent down at 121.6 cm from the top [i.d.].

I design the various vented TLs based on basic T/S vented alignment and 1/4 WL pipe resonance theory.

GM