Hello all
I have the sansui SP 1200 vintage speakers I have changed the capacitors. The speakers are working ok but need to ameliorate the low frequencies and replace the 10inch woofer with better one that can handle more power too.
The actual woofer (the W103 7ohms nom. 20W) is crossed at 700hz with a 3way 12dB/oct parallel crossover.
Speaker's specs :
8Ω, 92dB, 60Wats peak
it has 2 Squakwers S104 15ohms and 2 tweeters T103 17ohms
I guess i need to fine a woofer with
1 the woofer's part which is small in volume and is has dumping material with 2 ports
2 the upper part with the tweeters has no dumping material
the 2 parts of the enclosure are not closed there is a gap behind above the woofer
Also the crossover does not have any filter on the woofer so might need to add an inductor?
Most of the drivers I see are for professional speakers and for PA speakers and maybe not flexible for home hi-fi ? can I use one of those?
I need help to find a driver
Thank you
I have the sansui SP 1200 vintage speakers I have changed the capacitors. The speakers are working ok but need to ameliorate the low frequencies and replace the 10inch woofer with better one that can handle more power too.
The actual woofer (the W103 7ohms nom. 20W) is crossed at 700hz with a 3way 12dB/oct parallel crossover.
Speaker's specs :
8Ω, 92dB, 60Wats peak
it has 2 Squakwers S104 15ohms and 2 tweeters T103 17ohms
I guess i need to fine a woofer with
- Low Qts because the enclosure is small not more than 20 liters reflex with 2 dumped ports
- sensitivity 96 dB
- Impedance 8oms (with not less than 4ohms drop down)
- magnet weight 50oz ?
- coil diam 2 inch or 2.5 cm
- low Fs
- freq response 30-5000Hz
1 the woofer's part which is small in volume and is has dumping material with 2 ports
2 the upper part with the tweeters has no dumping material
the 2 parts of the enclosure are not closed there is a gap behind above the woofer
Also the crossover does not have any filter on the woofer so might need to add an inductor?
Most of the drivers I see are for professional speakers and for PA speakers and maybe not flexible for home hi-fi ? can I use one of those?
I need help to find a driver
Thank you
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Is the two tubes filled with damping material? If so it is not a bass reflex box but with resistive loading.
What is the problem with the bass driver? if you use vinyl as source you might get out subsonic rumble that can cause the bassdriver to swing around.
What is the problem with the bass driver? if you use vinyl as source you might get out subsonic rumble that can cause the bassdriver to swing around.
This will be difficult.
High sensitivity woofers of this size don't go very low.
Are you sure the existing woofer has 96 dB sensitivity?
Edit:
Those speakers seem to have a system sensitivity of 92 dB, so 96dB for the woofer seems reasonable. But they are known for lacking bass, apparently:
https://audiokarma.org/forums/index.php?threads/sansui-sp-1200.783863/
Maybe place them near a wall or in the corner?
Or adjust the bass knob on the amp 😎
I don't think the tubes are filled with the material. It is stated on the manual as a reflex cabinet.
The actual driver is ok but looking for better quality driver
yes they lack of bass.
That is why I am looking the change the woofer for more detailed bass . and also that can handle more power.
I have the brochure.
I have them for so many years... I've tried everything.
The knobs are connected only on the mids and tweeters.
The woofer is independent. The circuit can even be modified and play on separate amp.
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It looks like somebody stuffed the ports, first thing I would do is take the stuffing out of the ports and then try them again. You might be surprised at the amount of bass that comes out. 🫢
Also, you say you don’t think the woofer has a crossover on it. 🧐
But then above you stated that it’s crossed over at 700 Hz 12 db. Per octave…. It looks like there are three inductors on the crossover, the large one is most likely for the woofer.
Also, you say you don’t think the woofer has a crossover on it. 🧐
But then above you stated that it’s crossed over at 700 Hz 12 db. Per octave…. It looks like there are three inductors on the crossover, the large one is most likely for the woofer.
You can use the L-Pads to match the output of a woofer with a more common sensitivity.
It looks like your woofers are front-loaded so that gives you many options.
Check the woofer measurements but this should be a drop-in replacement
https://www.visaton.de/en/products/drivers/woofers/w-250-8-ohm
No nobody stuffed the ports. I was the first owner (much younger then yes!!) and the only one who opened them when I changed the capacitors in 2018.
The SP1200 SP1700 and the SP2500 have the same design. I can try stuffing out but this was made by sansui.
Also if I remember correctly the crossover has 2 transformers one for each switches (for mid-ranges and tweeters) and one inductor on the mid-range circuit. There are also 2 resistors one on each switch.
Everything is in parallel the woofer has nothing on it.
The details about the 700hz crossing e 12db/octave are from the specs.
The SP1200 SP1700 and the SP2500 have the same design. I can try stuffing out but this was made by sansui.
Also if I remember correctly the crossover has 2 transformers one for each switches (for mid-ranges and tweeters) and one inductor on the mid-range circuit. There are also 2 resistors one on each switch.
Everything is in parallel the woofer has nothing on it.
The details about the 700hz crossing e 12db/octave are from the specs.
thank you
Yes I always thought about the front loaded (because of the upper part of the enclosure?)but I was not sure
I'll check the woofer of the link
What do you mean for the l-pads?
the actual speaker don't have analytical bass.. yes I don't want to hit the bottom but need to ameliorate the actual speaker
there are 3 positions Clear-Natural and soft I always use them on natural I guess if I put them on Clear they will be bypassed?
If I replace the woofer with the W250-8 could I hook them on a more powerful amplifier?
I am asking this because the other sansui models SP1700 and SP2500 have the same set up but different larger woofers can handle more power.
If I replace the woofer with the W250-8 could I hook them on a more powerful amplifier?
I am asking this because the other sansui models SP1700 and SP2500 have the same set up but different larger woofers can handle more power.