Snell Type A Midrange Phillips AD5060 vs 62 Specs

[Pete B]

aroostookme writes:

>

>The one on the bottom not in a canister is the Snell A mid.

>The other two in their original canisters are from the

>Dahlquist 10's and have the same markings as the Snell A

>mids.

Your pictures are absolutely of the AD5060SQ version, the midrange or "squaker". The woofer version had a different edge and dust cap, at least the samples that I have.

However, in the Dahlquist DQ-10 the rear chamber was removed (or perhaps they made a special order without the rear chamber) and it was mounted with the rear open with a piece of felt over the back. This has been clear in every picture that I've seen of DQ-10s.

I don't know about the Snells but the pictures that you have there with the rear chamber look exactly like the stock AD5060SQ8. I don't know if a 4 ohm version was ever made and it would be good if you could measure the DC resistance.

Pete B.

I was just asked to post the specs for the AD5060/SQ8, so I pulled out

an old Phillips data book and found something interesting. First off, I went

and checked the samples that I have here which turned out to be:

AD5060/SQ8 midranges with rear chamber which is held on with screws

AD5060/W8 woofer without chamber

The data book has only one SQ version and it is the AD5062/SQ8, there

is no AD5060/SQ8 listed. There is also an AD5060/W8 and 5062/W8, it

is clear that the 62 version has higher power handling probably due to an

aluminum voice coil former since all other specs are the same.

I had an AD5060/SQ8 fail due to voice coil overheating and it did have just

a paper former, without aluminum.

Thus the only specs I can give are on the AD5062/SQ8, here they are:

Impedance availability 4/8

Fs 220 Hz

VC diam: 1"

Magnet: 10 oz

RMS PHC: 20/50 (50 over 800 Hz)

Operating Power: 4 W

Freq Range: 400-5000

Surround: Textile

Here are a few more 5" types listed:

AD5061/SQ main difference sealed metal frame back with 680 Hz Fs

AD5061/M Midrange version with whizzer cone, probably for table radios

AD5060/W Woofer version with rubber edge and Fs = 65 Hz, large peak in FR.

Note these power differences for the AD5060/W8 vs 62 versions of the woofer:

AD5060/W8 RMS PHC = 10, Operating = 8, P. Max = 15 W

AD5062/W8 RMS PHC = 20, Operating = 8, P. Max = 40 W

More data is given for the woofer which might also apply to the SQ version:

DC resistance: 7 for 8 ohm, 3.2 for 4 ohm

Moving mass: 6 g

BL: 5

Piston diam: 87 mm

Piston area: 59 mm^2

Magnet: 230 g

Air gap height: 5 mm

VC height: 6.3

Fs: 65

Compliance: 1.25 mm/N

Vas: 5.2 liters

Qms: 3.8

Qes: .66

Qts: .56

The AD5062/SQ probably completely replaced the AD5060/SQ since they wanted to

avoid burn out in the high end systems that used this driver. I strongly suggest

using the 62 version if it can be found.

A picture of the AD5060 without the rear chamber:

http://baselaudiolabs.googlepages.com/AD5060Sq8.jpg

Anyone going to provide a schematic for the Snell Type A, I would like to have a

Look?

Note when looking for replacements that the Xmax of even the woofer version is

only .65 mm and therefore a short throw mid from SEAS or Vifa would likely work.

The much longer throw mini woofers will have far lower efficiency and would not

make a good replacement.

[Pete B]

I'd consider this SEAS mid if the Snell A employs an 8 ohm driver:

http://www.madisound.com/catalog/product_i...roducts_id=1315

A proper chamber would have to be chosen and crossover mods

might be required.

[Pete B]

I'd consider this SEAS mid if the Snell A employs an 8 ohm driver:

http://www.madisound.com/catalog/product_i...roducts_id=1315

A proper chamber would have to be chosen and crossover mods

might be required.

Carl's schematic shows the mid as a 4 ohm unit so the above driver

would not be a good match:

http://www.classicspeakerpages.net/IP.Boar...ost&p=73025

Don't know if a 4 ohm version of that

driver is available.

[Guest Bluzmaster]

Carl's schematic shows the mid as a 4 ohm unit so the above driver

would not be a good match:

http://www.classicspeakerpages.net/IP.Boar...ost&p=73025

Don't know if a 4 ohm version of that

driver is available.

The mid in my Type A's read DC resistance of 6.2 ohms. See my post w/ pics of 5 minutes ago in the string "Classic Snells."

JH

[Pete B]

The mid in my Type A's read DC resistance of 6.2 ohms. See my post w/ pics of 5 minutes ago in the string "Classic Snells."

JH

I think now that the mid is an 8 ohm driver based on your measurement

and the values used in the crossover.

I've never worked on a Snell A, do your mids have the plastic rear

cup installed?

[Guest Bluzmaster]

I think now that the mid is an 8 ohm driver based on your measurement

and the values used in the crossover.

I've never worked on a Snell A, do your mids have the plastic rear

cup installed?

Pete -

No, they don't. The Type A has a closed "cardboard tube" type of chamber, within the upper unit, glued to the rear surface of the face. And here's a little mystery.

I ran the dimensions last night to compare the interior volume of the factory "chambers" (of the 5060's I just got off eBay) to the built-in chambers integral to the Type A, and the Snell chambers are approximately 20% greater in volume! (I'll post some pics and the specific numbers when I get home later on, if anyone's interested).

What effect would this different 'enclosure' size have on speaker performance? Seems to me that Philips would know the ideal cu. in. and that a greater volume enclosure may possibly allow excessive cone-excursion.

Any thoughts about this curiosity?

[Guest Bluzmaster]

Here's the specifics I was talking about:

Philips AD5060/SQ8 Rear Chamber Specs:

I.D. - 3.9375" dia. x 4" lngth.

Rear Chamber Volume = 48.7069579 cu. in.

Snell Type A Midrange Chamber Specs:

I.D. - 4.5" dia.x 3.875" lngth.

Midrange Chamber volume = 61.62921 cu. in.

Snell chamber is approximately 26% greater volume than factory chamber!

[Pete B]

Pete -

No, they don't. The Type A has a closed "cardboard tube" type of chamber, within the upper unit, glued to the rear surface of the face. And here's a little mystery.

I ran the dimensions last night to compare the interior volume of the factory "chambers" (of the 5060's I just got off eBay) to the built-in chambers integral to the Type A, and the Snell chambers are approximately 20% greater in volume! (I'll post some pics and the specific numbers when I get home later on, if anyone's interested).

What effect would this different 'enclosure' size have on speaker performance? Seems to me that Philips would know the ideal cu. in. and that a greater volume enclosure may possibly allow excessive cone-excursion.

Any thoughts about this curiosity?

Fc is square law with regard to total compliance so we'd have to quadruple

the total compliance to reduce Fc to 1/2 of the stock cup design. So this

difference is highly insignificant, but interesting, thanks for reporting it.

Your AD5060SQ8s look like mine except for the edge, is that foam? Sorry

to say it looks rotted. Mine have a treated cloth edge.

[Guest Bluzmaster]

Fc is square law with regard to total compliance so we'd have to quadruple

the total compliance to reduce Fc to 1/2 of the stock cup design. So this

difference is highly insignificant, but interesting, thanks for reporting it.

Your AD5060SQ8s look like mine except for the edge, is that foam? Sorry

to say it looks rotted. Mine have a treated cloth edge.

No, it's definitly a treated fabric surround on mine, too. It does kind of look like foam in the picture, though. That's all I'd need is more rotting foam.

[Guest Bluzmaster]

Pete -

I just ran into this website:

http://hupse.eu/radio/speakers/A.htm

I'm passing it along in case you've not seen it. I also found that by googling "translate Dutch" you can find a site to past-in the Dutch and get a reasonable translation.

Now, I notice that it lists this driver as having "...textile edge covered in black rubber." Mine clearly do NOT, as you can see in the photo I posted. I'm not sure what to make of this.

Joseph

[Guest Bluzmaster]

I was just asked to post the specs for the AD5060/SQ8, so I pulled out

an old Phillips data book and found something interesting. First off, I went

and checked the samples that I have here which turned out to be:

AD5060/SQ8 midranges with rear chamber which is held on with screws

AD5060/W8 woofer without chamber

The data book has only one SQ version and it is the AD5062/SQ8, there

is no AD5060/SQ8 listed. There is also an AD5060/W8 and 5062/W8, it

is clear that the 62 version has higher power handling probably due to an

aluminum voice coil former since all other specs are the same.

I had an AD5060/SQ8 fail due to voice coil overheating and it did have just

a paper former, without aluminum.

Thus the only specs I can give are on the AD5062/SQ8, here they are:

Impedance availability 4/8

Fs 220 Hz

VC diam: 1"

Magnet: 10 oz

RMS PHC: 20/50 (50 over 800 Hz)

Operating Power: 4 W

Freq Range: 400-5000

Surround: Textile

Here are a few more 5" types listed:

AD5061/SQ main difference sealed metal frame back with 680 Hz Fs

AD5061/M Midrange version with whizzer cone, probably for table radios

AD5060/W Woofer version with rubber edge and Fs = 65 Hz, large peak in FR.

Note these power differences for the AD5060/W8 vs 62 versions of the woofer:

AD5060/W8 RMS PHC = 10, Operating = 8, P. Max = 15 W

AD5062/W8 RMS PHC = 20, Operating = 8, P. Max = 40 W

More data is given for the woofer which might also apply to the SQ version:

DC resistance: 7 for 8 ohm, 3.2 for 4 ohm

Moving mass: 6 g

BL: 5

Piston diam: 87 mm

Piston area: 59 mm^2

Magnet: 230 g

Air gap height: 5 mm

VC height: 6.3

Fs: 65

Compliance: 1.25 mm/N

Vas: 5.2 liters

Qms: 3.8

Qes: .66

Qts: .56

The AD5062/SQ probably completely replaced the AD5060/SQ since they wanted to

avoid burn out in the high end systems that used this driver. I strongly suggest

using the 62 version if it can be found.

A picture of the AD5060 without the rear chamber:

http://baselaudiolabs.googlepages.com/AD5060Sq8.jpg

Anyone going to provide a schematic for the Snell Type A, I would like to have a

Look?

Note when looking for replacements that the Xmax of even the woofer version is

only .65 mm and therefore a short throw mid from SEAS or Vifa would likely work.

The much longer throw mini woofers will have far lower efficiency and would not

make a good replacement.

Hey Pete!

Look what just shook out of the bushes...

Joseph

[Pete B]

Pete -

I just ran into this website:

http://hupse.eu/radio/speakers/A.htm

I'm passing it along in case you've not seen it. I also found that by googling "translate Dutch" you can find a site to past-in the Dutch and get a reasonable translation.

Now, I notice that it lists this driver as having "...textile edge covered in black rubber." Mine clearly do NOT, as you can see in the photo I posted. I'm not sure what to make of this.

Joseph

Yes mine have a very thin coat of a black rubber material, so thin that

you can see the cloth fiber pattern.

I don't know anything about these in particular but some say that butyl

rubber was typically used for edge treatment. Roy mentions a Permatex

product for restoring cloth edges and I've also heard that Shoe Goo is

a butyl rubber compound. There have been discussions in the AR forum

concerning how to thin these products for use in restoring an old cloth

edge. Yours look as if the rubber coating decomposed for some reason,

or perhaps it's just the picture.

[Pete B]

Hey Pete!

Look what just shook out of the bushes...

Joseph

Ah, nice find, I've not seen that. The only new data is the difference in DC

resistance, still interesting.

[Pete B]

I have an AD5060/SQ8 that I purchased many years ago, probably from about 1979.

It is in essentially perfect condition.

Measured the T&S parameters with the cup on:

Rvc = 6.51

Fc = 233.8 Hz

Qt = .89

Qe = 1.41

Qm = 2.38

In free air with the cup removed:

Fc = 100.9 Hz

Qt = .48

Qe = .60

Qm = 2.6

Zin1K = 7.64 ohms

ZinMin = 7.19 at 569 Hz

Zin10K = 18.6

Lvc5K = .27 mH