My friend gave me this pair of speakers and i was thinking they may need some tweaking for hifi listening.
Woofer is Celestion, i have sent message to them to see if they have some info. Waiting for response.
Tweeter seem to be MB Quart MCD25M but there seem to be some variants.
Box is 25liter and there is a vent thats 45mm diameter and 18mm deep ,just a round cutout in front of box.
Filter is a bit weird but its probably tweaked for the application.
Maybe need to borrow mic and driver measurement equipment from friend or just alter the crossover abit.
It does not play very low but i guess its a combination of woofer/box and the weird capacitor in series with woofer.
Woofer is Celestion, i have sent message to them to see if they have some info. Waiting for response.
Tweeter seem to be MB Quart MCD25M but there seem to be some variants.
Box is 25liter and there is a vent thats 45mm diameter and 18mm deep ,just a round cutout in front of box.
Filter is a bit weird but its probably tweaked for the application.
Maybe need to borrow mic and driver measurement equipment from friend or just alter the crossover abit.
It does not play very low but i guess its a combination of woofer/box and the weird capacitor in series with woofer.
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The capacitor could also be meant to reduce the lower cut-off frequency. The capacitor and the impedance of the loudspeaker in its box are then designed to have a combined response that extends down to lower frequencies than without the capacitor, but the roll-off below the cut-off frequency is steeper.
There is a name for that, but I can't remember what it was.
There is a name for that, but I can't remember what it was.
Back in the day, turntables often had a rumble problem. That would be my guess. It saves a small woofer from a lot of grief.
Quite possible, and with that value it's probably also been selected to give a little bass boost before rolling off.
680uF and 8 ohm mean a 30Hz highpass.
It will definitely not affect Bass, specially in a small speaker which does not reach that low anyway.
It will definitely not affect Bass, specially in a small speaker which does not reach that low anyway.
Celestion DL-8 is a very similar speaker but ithink the tweeter might be different.
Dl-8 also has a cap is series but the main difference is that the box is sealed so my thinking is to make this one also sealed as a test.
Old speaker but the caps meaures ok in capacitance/esr/dissipation, even if speaker is not playing so low it is very nice in midrange, Tweeter is pretty good even if i dont favor this kind of metaldome(maybe titanium)
I am mainly doing this as a learning experience and i understand that you cant expect to much from this old construction.
The capacitor on the woofer was new to me but now i understand the function.
Dl-8 also has a cap is series but the main difference is that the box is sealed so my thinking is to make this one also sealed as a test.
Old speaker but the caps meaures ok in capacitance/esr/dissipation, even if speaker is not playing so low it is very nice in midrange, Tweeter is pretty good even if i dont favor this kind of metaldome(maybe titanium)
I am mainly doing this as a learning experience and i understand that you cant expect to much from this old construction.
The capacitor on the woofer was new to me but now i understand the function.
There was an old design by Dick Olsher that used the same tweeter, The Dahlia Debra.
Interesting high slope filter.
https://www.blackdahlia.com/articles/dahlia_debra.htm
Interesting high slope filter.
https://www.blackdahlia.com/articles/dahlia_debra.htm
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Yes, the 680 uF series capacitor converts the OP's vented enclosure from 4th order to 5th order bass loading.
Wharfedale used the technique in the original small, rear vented, Diamond speaker.
We seem to be cooking with gas here!
The woofer might be that old bass light 8" paper cone used in the Celestion Ditton 15:
Never liked that one much... too bright.
Just a coil on the bass and LC tweeter. Needed attenuation IMO.
This is the undersized closed box Wharfedale Laser 90B:
Familiar sort of crossover, note the negative polarity on the tweeter, which works because of the approx 5cm delay on the woofer at around 3kHz. Half wavelength being about 5cm. KEF used 2.7mH and 4.7uF in some paper coned models.
The 0.05mH coil applies some rolloff to the polyamide tweeter, just like the Zobel in your model does. The 450uF capacitor is often applied to undersized closed box.
That third order tweeter filter is classic Celestion style, as it goes.
Best, Steve.
The woofer might be that old bass light 8" paper cone used in the Celestion Ditton 15:
Never liked that one much... too bright.
Just a coil on the bass and LC tweeter. Needed attenuation IMO.
This is the undersized closed box Wharfedale Laser 90B:
Familiar sort of crossover, note the negative polarity on the tweeter, which works because of the approx 5cm delay on the woofer at around 3kHz. Half wavelength being about 5cm. KEF used 2.7mH and 4.7uF in some paper coned models.
The 0.05mH coil applies some rolloff to the polyamide tweeter, just like the Zobel in your model does. The 450uF capacitor is often applied to undersized closed box.
That third order tweeter filter is classic Celestion style, as it goes.
Best, Steve.