Restoring a pair of Sansui SP L700 speakers.

Discussion in 'Speakers' started by Ken Boyd, Feb 6, 2012.

  1. Ken Boyd

    Ken Boyd AK Subscriber Subscriber

    Messages:
    12,104
    Location:
    Florida
    I purchased a pair of Sansui SP L700 speakers from an eBay auction about a month ago, and was really excited to get them as they looked like they would be a very good sounding pair of speakers. When I got them and hooked them up, I was quite dissapointed with there sound, so I decieded to attemped to restore them and hopefully they will sound a lot better. They lacked bass IMO having twin 10 inch bass drivers and a single horn behind an acustical lens, I thougth they would be a nice change from my usual speaker by being an easy to driver with a smaller nice amp and pre amp, without the need for such a large expensive amp that my other speakers all require.

    I will take a lot of pics and let everyone know what I think when done. I could only take two evenings of listening to them before I removed them from the system. Other than looking nice, and being built very well, they sounded very bad.

    Sansui SP L 700 manufactored in 1976 cost 210,000 yens, or $2,303.00 per pair.

    [​IMG]

    Pulled the two bass drivers out, I couldn't tell that one of them the foam had pulled off the bass cone, the foam surrounds on these, glue to the back of the cone rather than the front, thats good, I won't have to worry about any glue oozing out on the front of the cones when I refoam them, hope to find the right foams, that might be a bit harder.

    Pulled all the bass drivers out, one where the foam has split off the back of the cone. All the baskets are cast, nice size magnets,

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]


    [​IMG]

    Bass tuned port made of wood goes along the bottom and then turns up the back, all the sound deading material is fasten to the sides

    [​IMG]

    Crossover looks pretty simple for a recap, looks like only two caps pre pretty decent sized ones. couple of resistors, and some inductors.

    [​IMG]
     
  2. cubdog

    cubdog banging through drywall Subscriber

    Messages:
    20,802
    Location:
    Oregon IL.
    Good luck with your project Ken.

    cubdog
     
  3. Ricky1

    Ricky1 Lit by beacon fire

    Messages:
    58
    Location:
    MN
    Wow, that's some pretty awful tearing on the foams. Hope this works out, I'm excited for it!
     
  4. dc270

    dc270 Now Off The Reservation..... Subscriber

    Messages:
    12,078
    Location:
    North Texas
    Little wonder they sounded poorly- the foams are pretty well gone! I bet they have large potential to sound good though!! I will be following- nevr knew Sansui made such nice, well made speakers!!
    DC
     
  5. ZeroJunk

    ZeroJunk AK Subscriber Subscriber

    Messages:
    1,096
    Location:
    Browns Summit N.C.
    After listening to big Infinitys I have found it difficult to find anything else that sounds good to me.
     
  6. jmosher

    jmosher Active Member

    Messages:
    117
    Location:
    Kaysville, Ut
    Looks interesting Ken. I will stay tuned.
     
  7. Ken Boyd

    Ken Boyd AK Subscriber Subscriber

    Messages:
    12,104
    Location:
    Florida
    I have never rebuilt a crossover before, and since this one looks pretty easy I jumped in to give it a shot. Question for the AK members, do I need to worry about those two white resistors, and those two coils, I think they are called inductors. Do they need to be replaced or just the two caps?
     
  8. Ken Boyd

    Ken Boyd AK Subscriber Subscriber

    Messages:
    12,104
    Location:
    Florida
    I think I am finding that out, but these should sound better than what they did, the foam for sure was a problem, but I have a hard time beleiving that these speakers shouldn't sound pretty good if everything is up to spec, am I wrong?
    I personally have not be very inclined to own Sansui speakers but these looked like a different breed from the majority of ones I have seen.
     
  9. dc270

    dc270 Now Off The Reservation..... Subscriber

    Messages:
    12,078
    Location:
    North Texas
    These are certainly a fresh departure from the Kabuki types that many of the over sea products were known for being- they should sound really nice!

    The resistors and inductors should be fine as they are. get you some nice Dayton 5% tolerance poly caps from PE and you are in business again!
    DC
     
  10. kermit z

    kermit z Loud Music saves Lives!! Subscriber

    Messages:
    8,899
    Location:
    Denver CO
    Those sure do look nice. Once your done, let us know how they sound :)
     
  11. Ken Boyd

    Ken Boyd AK Subscriber Subscriber

    Messages:
    12,104
    Location:
    Florida
    Ok today I removed the horn driver behind the accustical lens, unit states 7 ohms, the bass drivers have are marked 13 ohms. The horn is pretty heavy for its size.

    Removed Horn driver


    [​IMG]

    [​IMG]


    Here is a pic of the crossover removed


    [​IMG]


    [​IMG]
     
  12. Ken Boyd

    Ken Boyd AK Subscriber Subscriber

    Messages:
    12,104
    Location:
    Florida
    Well I have the crossovers out and it contains only two caps, they are located inside the aluminum cover which has an epoxy around them which is pretty hard to remove but on the cover it states, 125 WVAC 5.6 UF so I guess thats the value of the cap inside the cover. I checked out parts express and found about 6 or 7 different manufactors for them, ranging from price of about 40 dollars each to 3 dollars each. The Solans are $4.23, Kimber Cap $23.50, Janzten $4.18, Dayton $2.13, Auricap 6.0uF 400V Capacitor $25.45, Audiocap PPT Theta 6.0uF 200V Film/Foil Capacitor $37.47, a large price range of caps.

    So what would be the real world difference. I need four, and I don't know how much of a difference the expensive ones will be over the cheap ones. I had a fellow AK member who has the same speakers use the Janzten he stated his speakers sound great, but I have found a lot of people claim great sound, from speakers that I personally would not consider great no matter what you did to them in keeping that in prespective, and the fact, these speakers might not sound good no matter what I do, is the more expensive caps worth the extra money. On the other side of the coin I don't want to put a cheap cap in and then think the speakers sound bad and not realise it was because of the cheap caps. The Jenzten ones he used were non polorized I take it that it would not matter which direction you solder them in, is that good or would a polorized one be better?

    Any input on this would be helpful as I have never done this before.

    Also one of those ceramic resistors the top seems to come off, and you can see a wire winding in the ceramic, is the top suppose to come off, the top cover is made out of the same material as the bottom with you can see a little bit of the wire coil embedded in the ceramic. It has 12 Ohm K on the side of it about 2 inches long.
     
    Last edited: Feb 9, 2012
  13. Tom Brennan

    Tom Brennan AK Member Subscriber

    Messages:
    13,834
    Location:
    St. Augustine
    You could be, that a speaker is well made is no guarantee it will sound good, indeed many very bad sounding speakers (IMO) were very well made. No doubt everyone here can give examples of well made speakers they despise.
     
  14. avguytx

    avguytx AK Subscriber Subscriber

    Messages:
    8,499
    Location:
    Central AR
    Personally, I avoid Parts Express like the plague when at all possible. Madisound has the 5.6uf Solen caps for $3.50 each and the ClarityCap PX series 5.6uf caps for $5.85 each. Those 2 are my picks above all else for the money and what I used (the Solens) on most all of my speakers. There are better caps, yes, but you do pay for them. Just my $.02 of course.
     
  15. Ken Boyd

    Ken Boyd AK Subscriber Subscriber

    Messages:
    12,104
    Location:
    Florida
    What kind of audio difference would I be able to notice? Would having the more expensive caps make a night and day difference, or just a slight difference and what would the difference be?
     
  16. Ken Boyd

    Ken Boyd AK Subscriber Subscriber

    Messages:
    12,104
    Location:
    Florida
  17. avguytx

    avguytx AK Subscriber Subscriber

    Messages:
    8,499
    Location:
    Central AR
    Haha.... I don't know about "wonders". For that kind of money, I'll be wanting a few hour lap dance from the best gal they can find! :D
     
  18. avguytx

    avguytx AK Subscriber Subscriber

    Messages:
    8,499
    Location:
    Central AR
    I've never gone crazy expensive on caps and I have tried other high end ones in the past. For my ears, the differences aren't "slap yo momma" drastic enough to spend the extra ducks. Solens are used by quite a few high end speaker companies and that's good enough for me.
     
  19. redbeard74

    redbeard74 AK Subscriber Subscriber

    Messages:
    196
    Location:
    Monroe, Georgia
    The Solens or the Clarity Caps sound like a good investment.
     
  20. Ken Boyd

    Ken Boyd AK Subscriber Subscriber

    Messages:
    12,104
    Location:
    Florida
    Ok kind of wondering why the Solens are so cheap but they are on their way, along with foam kits to refoam the bass drivers. Hopefully they will be done by next week.
     

Share This Page