Some sample graphs, some big differences

[loninappleton]

Without having what might be good specifications for a discontinued speaker, I'm playing Joe Detective.

The Old Pioneer K1VA8 went out of production at Pioneer.
Parts Express still has it on File:

http://www.partsexpress.com/pe/pshow...TOKEN=90160100

The cost of the item was $10.00.

A newer part with slightly larger dimensions but at the same price
and more realistic graphing and complete info ....

http://www.partsexpress.com/pe/showd...number=290-010


... leads me to believe the older product (has a ring around the front for rear mounting to plastic (car speaker etc.) now has a different industrial flange also used for rear pressure mounts.

Can I bet on the new specs to be closer to reality? Just close-- no cigar.

These things cost 50 cents each at closeout. But I want to use the
BIB calculator to put them in a test box.

The big number difference is in the Vas-- practically non-existent on the 50 center discontinued ones.

Trying Pioneer plus the keyword data sheet didn't get me anything either.

[Godzilla]

I think gychang built BIBs with these to good effect.

Godzilla

[loninappleton]

Originally posted by Godzilla
I think gychang built BIBs with these to good effect.

Godzilla

Yes I had recently seen that. My question was one of request for speculation on if the specifications as listed for the item could be even reasonably used for older item of which I have a bunch.

If I used the more complete number set from the newer Pioneer is it likely that I'd get a better build result since various of the numbers for the older Pioneer K1VA8 where simply missing at the Parts Express data sheets.

Example of the current $10 Pioneer:

http://www.partsexpress.com/pdf/290-010z.txt

(contains a complete set of T/S params at the bottom


Example of the older $10 Pioneer K1VA8

http://www.partsexpress.com/pdf/269-568.pdf

(has only partial listing of T/S params and one -- the Vas -- which is extremely low.)

This is just a test build with a very inexpensive driver. My curiosity was piqued when a sample install yielded interesting results. If I can improve it with better entries into the calculator, that is my goal.

[GM]

Originally posted by loninappleton

The big number difference is in the Vas-- practically non-existent on the 50 center discontinued ones.

No 'practically' about it, zero means none, ergo it wasn't measured. Anyway, what's all that wrong about using the specs listed in the description? I mean what's measured is close enough to those, so it seems reasonable that Vas would be too.

GM

[loninappleton]

Originally posted by GM


No 'practically' about it, zero means none, ergo it wasn't measured. Anyway, what's all that wrong about using the specs listed in the description? I mean what's measured is close enough to those, so it seems reasonable that Vas would be too.

GM

Well, I've tried to be as thorough as possible with this and in the PE description a Vas of .08 was given. That .08 Vas is what I used in the
calculator.

So your suggestion (and I know it's only that) is to use the
Vas and so forth from the new replacement/similar product (?).

The resulting change might be small or large. I'm just not experienced enough with the calculator or specification swapping
to know. So I can go ahead and plug in the revised numbers and
see what happens. I suppose I could have done this by now but
with ou an advisory i wouldn't really know if anything was accomplished.

[loninappleton]

That pesky Vas measurement in the new Pioneer (see above)
skewed the calculator.

If the original measurements gave a bungalow, the new figures give a McMansion.




So the specs given are still questionable.

Using the old Vas of .08 and the newer other numbers gave a slimmer and smaller cabinet which is another goal for this project.

I mixed and matched because the graph in the newer one appears to
represent the actual speaker output of 15,000 hz (shows a dropoff
above that) whereas the old 50 cent graph does not represent it accurately.

So I'm still playing around.

[Godzilla]

>>> So I'm still playing around.

These are the perfect 'play around' drivers anyway. I hope you get good results. Please report back. Since hearing the TB 871 was discontinued maybe this driver can be used as a good bang for the buck. Good cheap full range drivers seem to be becoming less available.

[sreten]

Hi,

The specs state 0.08cuft / 2.3L old, the new 0.31cuft / 8.8L .

The measured Vas is 3.4L, which far nearer the old version.

Interestingly MCM have some info on the "A11EC80-02F"
see part number 51-075 which indicates an Fs close to spec.

assume around 3L ?

/sreten.

[loninappleton]

Originally posted by sreten
Hi,

The specs state 0.08cuft / 2.3L old, the new 0.31cuft / 8.8L .

The measured Vas is 3.4L, which far nearer the old version.

Interestingly MCM have some info on the "A11EC80-02F"
see part number 51-075 which indicates an Fs close to spec.

assume around 3L ?

/sreten.

sreten:

I'm confused. The Vas states 3.93. But you have found .31.

How did you do that? Was this on MCM?

On the internet search I did, I looked up the old production part number of 10-1028LA/XCN on the Pioneer K1VA8 but not the
newer Pioneer item.

This .31 would put the size back into the acceptable range.

I'll fire up the calculator again and see what it gives back.

[loninappleton]

Originally posted by loninappleton


sreten:

I'm confused. The Vas states 3.93. But you have found .31.

How did you do that? Was this on MCM?

On the internet search I did, I looked up the old production part number of 10-1028LA/XCN on the Pioneer K1VA8 but not the
newer Pioneer item.

This .31 would put the size back into the acceptable range.

I'll fire up the calculator again and see what it gives back.

Whelp,

that .31 still gave a huge box.

I'm happy for construction purposes with a 6.5 x 9.5 x 32 in. inside
measure with a slant of about 28 in (rounding everything off for discussion' sake. It may be that the original spec. was in tolerance.