2204 to 2203

[gasfan]

Is this possible by changing surrounds?

[grumpy]

Is this possible by changing surrounds?

Not obvious that this idea would work at all as a 2203, unless much more were changed than the surround. Perhaps not even then.
The simple answer is no.



MODEL
FS
QTS
QMS
QES
VAS
EFF
PE
XMAX
RE
LE
SD
BL
MMS
FLUX*



















2203A
16
0.14
6
0.14
399.3
1.1
100
5.08
6.3
1.4
0.053
21
100
1.2


2203H
16
0.14
6
0.14
399.3
1.1
100
5.08
6.3
1.4
0.053
21
100
1.2


2204H
45
0.35
1.7
0.44
87.8
1.8
350
6.86
6.2
0.7
0.054
15
57
1.2

[RMC]

It will likely produce sound but that's about the only thing one can say. How good??

Looking at Grumpy's numbers, you can see the Vas parameter which represents suspension compliance. From 2204 to 2203, and assuming the rest is ok, that Vas number would have to go up 4.5 times!

However your hybrid driver would have a 2204 spider (likely stiffer) with a more compliant 2203 surround. The mix of these two is somewhat unknown on how the suspension will work.

According to EV, system performance is less affected by changes in suspension compliance than by other parameters. But its not totally insensitive to compliance variations. Eargle mentions in his Loudspeaker Handbook that when suspension compliance varies that causes the Vas and Qts parameters to shift. Vas is expected to vary here but Qts change is another side effect to maybe deal with.

Moreover, since Vas is related to proper box size (driver Qts also) then box Vb might need adjustment. Then i look at the driver efficiency equation, i note that Vas and Qes, among others, are considered for efficiency (and Qes is used to calculate Qts). This domino effect blurrs the picture...

If you were replacing with same type surround (due to an accident for example) my reply might be different, but here you're in uncharted territory.

Richard

[Robh3606]

Is this possible by changing surrounds?

What are you trying to do?? The closest I would think would be 121A's if you can find them. They are moded with a very heavy mass ring and a stiffened spider. They sound quite good but take a big sensitivity hit from the added mass.


http://www.audioheritage.org/vbulletin/showthread.php?39268-121a&highlight=121a

Rob :)

[grumpy]

So it's not that the notion didn't have merit:

http://www.audioheritage.org/vbulletin/showthread.php?58-2204-recone-in-2203

:cheers:

[Earl K]

Is this possible by changing surrounds?


Here's a more complicated answer as to why the answer is "No".

One can't make a 2203 out of the standard 2204 parts ( mostly ) due to these 2 drivers having radically different voice-coils ( check out the displayed Le & BL figures ).
- The figures indicate that the 2203's voice-coil has many more windings working within the "gap" of the magnetic assembly ( which do happen to be identical for the two models ).

The 2204's voice-coil is a bit "weak" to properly manage the extra weight of all the 2203's moving parts ( especially when including the "mass-ring" ).
- One consequence ( of the extra "MMS" ) will be a reduced upper midrange response ( if driving the "heavier" 2203 soft parts with the weaker 2204 voice-coil ) though maybe this isn't important to your usage(??).

:)

[edgewound]

Is this possible by changing surrounds?

No. Not that simple.

Different voice coil, different moving mass, as well.

That said...It's possible to make make a no surround rot 2203 with appropriate available parts. It's on my "to do" list. I've already done it with the 2235 and working on a 2245 that won't need new surrounds every ten years...and actually sound better.

[gasfan]

Here's a more complicated answer as to why the answer is "No".

One can't make a 2203 out of the standard 2204 parts ( mostly ) due to these 2 drivers having radically different voice-coils ( check out the displayed Le & BL figures ).
- The figures indicate that the 2203's voice-coil has many more windings working within the "gap" of the magnetic assembly ( which do happen to be identical for the two models ).

The 2204's voice-coil is a bit "weak" to properly manage the extra weight of all the 2203's moving parts ( especially when including the "mass-ring" ).
- One consequence ( of the extra "MMS" ) will be a reduced upper midrange response ( if driving the "heavier" 2203 soft parts with the weaker 2204 voice-coil ) though maybe this isn't important to your usage(??).

:)
I already have a pair of 2203 along with the rest of the components including xo for 4315s. What I want to try is doubling the 2203s in mag to cone isobaric.

[gasfan]

No. Not that simple.

Different voice coil, different moving mass, as well.

That said...It's possible to make make a no surround rot 2203 with appropriate available parts. It's on my "to do" list. I've already done it with the 2235 and working on a 2245 that won't need new surrounds every ten years...and actually sound better. What about trimming down a 2245 cone?:bouncy:

[gasfan]

What about trimming down a 2245 cone?:bouncy: no bouncy bouncy?

[edgewound]

What about trimming down a 2245 cone?:bouncy:

The cone profiles are not the same...so no. The voice coils are also different.

[gasfan]

The cone profiles are not the same...so no. The voice coils are also different.Thank you Ken. I should mention I did manage to round up a pair of 2203H in rough shape, arrived today. One has original cone with completely collapsed unsalvageable spider, no idea of vc condition. The other has aftermarket cone with rubber surround jimmied on. Nothing stopping me from dissecting them. I'll post pics tomorrow for verification they are actually 2203 baskets.

[gasfan]

So it appears to be a semi-good find for a couple of bucks? The oem vc is in great condition. The baskets are identical to the others I have.90347 John has come through so these will have new oem cones and I'll have a spare.