Hi All.
A friend of mine brought around a pair of Sansui D-40 Loudspeakers this weekend just gone. He knows I collect speakers.
A very unusual design, the covers are screwed in place from behind. A bad design flaw. I always remove the covers when playing loudspeakers.
I found that the wiring on one of the tweeter had snapped off, and the cap on the other was an empty shell.
I replaced the 0.47µF Tweeter electrolytic caps (old one measured .057µF) with equivalent poly caps, but left the 2.2µF electrolytics inplace (fresh out of spares).
Result. Very acceptable sound. Very listenable.
I think replacing the mid caps and adding inductors might further improve the sound.
My question is:
As I'm trying to stick to a budget (zero dollars so far), I was wondering whether fitting the iron core inductors junked from my TDL RTL3's?
It's a 10" woofer. The Sansui's are 8 ohm, 65w/c , & 93Db/1m.
A friend of mine brought around a pair of Sansui D-40 Loudspeakers this weekend just gone. He knows I collect speakers.
A very unusual design, the covers are screwed in place from behind. A bad design flaw. I always remove the covers when playing loudspeakers.
I found that the wiring on one of the tweeter had snapped off, and the cap on the other was an empty shell.
I replaced the 0.47µF Tweeter electrolytic caps (old one measured .057µF) with equivalent poly caps, but left the 2.2µF electrolytics inplace (fresh out of spares).
Result. Very acceptable sound. Very listenable.
I think replacing the mid caps and adding inductors might further improve the sound.
My question is:
As I'm trying to stick to a budget (zero dollars so far), I was wondering whether fitting the iron core inductors junked from my TDL RTL3's?
It's a 10" woofer. The Sansui's are 8 ohm, 65w/c , & 93Db/1m.
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Uhm...93 dB @ 1m...I guess 1 watt is used! And you know that putting a filter for bandwidth limiting it also limits the sensitivity data.
Well, that 93 dB is referred @ 1 kHz...
And you should know that if you limit the woofer's upper band, that band won't be reproduced by the same tweeter with the same filter.
Well...putting a coil in line with the woofer will reduce its output in the mid region and would produce the BSC shelving filter, so it's only the first step.
Well, that 93 dB is referred @ 1 kHz...
And you should know that if you limit the woofer's upper band, that band won't be reproduced by the same tweeter with the same filter.
Well...putting a coil in line with the woofer will reduce its output in the mid region and would produce the BSC shelving filter, so it's only the first step.
Xover apparently depends on natural HF rolloff from woofer an mid, so adding inductors will affect its proper operation.
But, if you already have some it cost you nothing to try.
If sound is good I recommend you to leave it as is, with caps only. Proper redesign of xover, with measurements and new more complex layout is most likely not cost effective.
Was there any stuffing in the box?
If not, you should add some light 10gramms/liter of polyester wadding to supress internal standing waves and HF reflections.
But, if you already have some it cost you nothing to try.
If sound is good I recommend you to leave it as is, with caps only. Proper redesign of xover, with measurements and new more complex layout is most likely not cost effective.
Was there any stuffing in the box?
If not, you should add some light 10gramms/liter of polyester wadding to supress internal standing waves and HF reflections.
Thanks D.
Wishful thinking on my part.
Don't know enough about "Inductor less" xover designs, and immediately thought they were skimping.
Then thinking it through, as you P touched upon, any Inductor would need to be based on measurements and nest the caps accordingly.
As you say, if I'm happy with the sound keep it as it is.
I think the easiest improvement will be to replace the 2.2µF electrolytics with polypropylene.
Both boxes had large folds of thick grey material with flecks of other colors, which seem to be doing the trick.
Out of interest I measured the iron core inductors which had been removed from a pair of TDL's @ 0.51 mH.
Ordinarily I avoid iron core, having a preference for air core Inductors, but thought, were iron core better than nothing.
But as what has been said, it would entail reconfiguring all the drivers.
Ordinarily I avoid iron core, having a preference for air core Inductors, but thought, were iron core better than nothing.
But as what has been said, it would entail reconfiguring all the drivers.