Sansui SP-3500's-

[super98lsc]

Updates:
If you guys recall I picked up this pair for 125.00 in cosmetically good shape with both 14" woofers needing to be rebuilt. One is stiff as a brick and the other has the surround separated from the cone edge.

• Vigman sent me a beater test woofer for the experiment (thanks again Mike).
• JBL 12" (Same as used in the L-100 cabinets) 8 Ohm.
• I fabricated an Oak adapter ring to fit the 12" into the factory baffle where the 14" once lived.
• For testing purposes I used my Sansui CD-10 Active Crossover in 4 way mode with my BA-2000 and AU-717 to drive the 4 different ranges. Doing so provides me with complete control of the cutoff frequencies and slopes to get the desired sound from the cabinet.
• Since this is purely testing I did not want any cutting or modification of the cabinet, thus I cheated and ran the 4 pair of of speaker wires out of one of the ports. Horrible but functional.
• At the moment I still have the planar mid-range installed (literally masked in place not hard mounted) The hole is sealed over in the back with a piece of Dynamat.

Results:

• Completely transformed the speaker!
• The bass is tight and quick and actually has depth to it.
• Once I tuned the crossover for a bit the results were quite pleasing.
• Mids and highs are clear and detailed
• The woofer starts to roll off around 45hz with the cabinet tuned as is. Nothing scientific here just a quick listening test while stepping down the sine wave generator at 1w of power.
• Woofer upper cutoff at 150Hz
• Squakers are start at 150-950
• Planar Mid-range starts at 950-7.5k
• Horn Tweeters start at 7.5k- to .....

Next Steps:
I will build a better ring for the woofer mount likely out of 3/16 aluminum and either brush it or flat black paint it and test some port length adjustments to see if I can bring the low end down another octave.

Build a new crossover with the desired cutoff points/slopes to mirror the settings tested on the electronic unit.

Lastly Ill have a good looking pair of vintage speakers that sound good for under $300.00 bucks.

 

[illinoisteve]

super98lsc, let me ask you this -- since you originally thought the SP-3500s might be an upgrade for a system then having SP-2000s in it, do you now think the SP-3500 design is better in any way from the SP-2000 design. I mean, if you could have a mint (right off the factory line) pair of 2000s and also a pair of mint 3500s, and had a chance to listen to them and inspect them in detail--which pair do you suspect might be superior, how much, and why? And if the 3500s were better, would they be better enough to justify the increase in size?

 

[super98lsc]

I cannot give a fair assessment since neither of of the woofers in my SP-3500s were any good. One is so tight it cannot move properly and sounds horrible, the other had the doped cloth surround torn off the cone edge all the way around. My SP-2000s do not sound bad for a 40+ year old speaker, the mid-range is somewhat over-driven on them for my tastes. What I did not like about the SP-3500 is the lack of a high cutoff on the woofer, Sansui used "the natural roll off" of the woofer in lieu of a crossover that will cut that upper end off. I find this makes the speaker sound cloudy and the bass is not as clean and detailed.

Quality wise the SP-2000 is just a better built speaker. The drivers are all Alnico magnets and they do not have any issues with cone edge, or surround drying up and failing completely or becoming so tight that it raises the F3 of the drivers.

The SP3500s:
I picked these up cheap and they looked new cabinet wise. I wanted to hear a pair since they were a joint venture with Sansui/JBL and had a fairly massive woofer. Well after bringing them home and removing the grills I realized the The JBL 12" woofer displaces less volume inside the cabinet, its basket and magnet depth is far more shallow than the Sansui woofer.

 

[super98lsc]

Tonight I swapped the original horn and lens back into the cabinet. Sounds better with the entire original high end. Some slight tweaks on the crossover points and less gain in that that range. Conclusion the top end is pretty decent if the x-over is redesigned. I ordered 3 more JBL 123A woofers today 8 Ohm and will assemble the other cabinet and test my own passive network in it until I get the same pleasing sound out of it as I do with the active network. The final test not that it matters as our ears are the final judge will be to test it with a spectrum analyzer and see how linear it ends up.

Human touch by Springsteen sounds great as well as Nortons Boogie by Bruce Katz.


At this point they sound very respectable.

 

[bd1886]

I have always really wanted a pair of big Sansui speakers because of how beautiful I find them but? I'm sure my ears have outgrown my eyes (at this point.....).
Old thread but it seems some experienced ears here have directed me to a jig, carpentry tools,patience and mahogany.