Sansui SP-3500 - An AK'er Gift and Restoration Project

4 days ago, in a thread far, far away ...

AK member 4-2-7 came out of nowhere and offered up a pair of Sansui SP-3500's for free, to me. He came right out and stated that I could go ahead and flip them. He'd read about my goings on and knew times were tight, flipping these speakers could very well help out. Was I interested? Sheeyit yeah!

It was an 80 mile round trip, not bad in holiday traffic. Finding his place was a straightforward situation, easy peasy. We spent about an hour hanging out, gabbing about music, equipment and our somewhat similar penchant for hanging out at clubs in the late '70's and early 80's. OH, and I got to see the right front headlight bezel of his '66 Ford Fairlane with a 427 4-speed. Schuhwing! We had a good time and he sent me home with a Pearl Harbor and the Explosions LP. Nice, eh?

Time really flew by, my truck got loaded and off I went. Well, okay I pretty much did the speed limit there and back. It was all about conserving gas on this trip, did pretty well too. I was proud of myself on that, I generally zip through traffic with authority. I pulled up, opened up the front door, opened up the shell on my truck and unloaded the little beasts. I stood there and stared for a bit. I was painfully hungry, blood sugar was dangerously low. Hook up speakers? Or make a sammich? You guessed it, hook up the speakers.

Getting the speakers in to place was a snap, I'd already readied the living room for my Rectilinear Audition from Sunday.



First off was Powerstation, seemed like an appropriate selection. Initially they were just on the floor and the bass was a little goofy, a little lacking. My Polk Monitor 5's didn't need their stands at the moment, so out they came and went under the Sansui's. Bass lowered a bit and with them tilted back, when standing I got a load of highs and mids. Nicely done!

Just for fun, I jacked in a load of Rammstein. Lordy. 15 watts of juicy, heart pounding power and these little beasts filled the room entirely, very efficient.

So, it looks as though sonically they're just fine. I'll pull and test the capacitors just for fun, but I'm not planning on a recap. The enclosures are a little rough in places and these will require a strip and hand-sand. As far as what with and how to complete the finish, I'm not there yet. One of the front, right corners is bashed in pretty well. That will need attention too.



After a decent listening to, I'll strip the components from the enclosures and test the capacitors. Then I think it'll be time for deoxit for the attenuators on the back. Once that's taken care of, the speakers and I can sit and have a discussion to see where it will all go from there.

Thank you 4-2-7, I truly appreciate the gift and will let Pearl Harbor spin tomorrow afternoon.

Biggles

ps - YES, I did get the grills!

I've always wanted a pair of those. Great score.

dat521gatherer said:

I've always wanted a pair of those. Great score.

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I can see why. The build quality on the enclosures is really supreme, very nicely done. The veneer work solid. The sound these little things produce is staggering, blew me away. They seem to a bit more finicky for room placement versus the Rectilinears, but that's not surprising. I still need to do some playing with them, see what I can come up with.

Over the last 3 days I've read tons on them from AK, read somewhere they were designed by JBL? Or some such, attempted to find that thread. No luck so far, kinda interesting. I'm really excited to open them up, see what's going on inside.

Biggles

Congrats! You know I'll be following. Two thumbs way up for 427. I could swear he built some speakers using cement forms (maybe someone else?). Great karma going there.

I hope to do mine, caps and all. But for me, they are anything BUT little guys. They be my largest speakers, to date anyway. I can see why they aren't for you.

drbiggles said:

I can see why. The build quality on the enclosures is really supreme, very nicely done. The veneer work solid. The sound these little things produce is staggering, blew me away. They seem to a bit more finicky for room placement versus the Rectilinears, but that's not surprising. I still need to do some playing with them, see what I can come up with.

Over the last 3 days I've read tons on them from AK, read somewhere they were designed by JBL? Or some such, attempted to find that thread. No luck so far, kinda interesting. I'm really excited to open them up, see what's going on inside.

Biggles

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Congrats on the 3500's. I did a road trip of 460 miles round trip last summer for a set of KLH 6's. Of course nothing in New Mexico is close. Ended up being a nice day trip with the Mrs.
I had a set of the similar 2500's that I gifted to my son. A well placed sub woofer did wonders for the 2500's for the low end.

A comment from a review page on google
Let me first say, I read the reviews here on the SP-3500 Sansui Speakers. I worked for customer service, JBL Sound in 1974 and we would recieve the SP-3500 speakers for repair. The Cabnet design and speakers were all designed by JBL for Sansui. The replacement speakers and network deviders are all manufactured by JBL, thats the reason why the sound is so great.

Some tech notes from the paper work: 14" woofer; 1st midrange 4" 2 cone-type; 2nd midrange 4.5" horn-type; tweeter 2" two horn-type; 100watts Max; 8ohms; 58lbs; ~25"x17"x11"; sensitivity 96dB/W; Range 25-20KHz normal listening; Crossover freq 700Hz,2,000Hz,6,500Hz; Cross directional firing.
Lastly, the package I have also has a Sansui dust cloth - not sure if it came with the speakers or other component, but it is certainly a nice touch

Quelle: Sansui Prospekt von Anfang der 70.er.

SP-3500 4-WAY 6-SPEAKER MULTI-DIRECTION SPEAKER SYSTEM Perhaps the most timely speaker system ever introduced, this new 100 watt Multi-Direction (MD)system takes you beyond the reproduction of sound source points to an incredibly lifelike method of reproduction approximating that of an original sound field. This makes the SP-3500 the foremost system available today for the new age of 4-channel stereo. The secret to the SP-3500's living sound lies in its Multi-Direction System, a new way of angle-mounting speakers within the enclosure to re-create within the listening room the complex interference of sound waves present in the original sound field. All six of the SP-3500's speakers, including a newly developed 14-inch woofer, were specifically selected to achieve this effect. Even Sansui's famed Kumiko fretwork grille has been redesigned in the SP-3500. lt now is gracefully curved to add to the overall elegance of this new system. For a totally new experience in sound reproduction, make it a point to audition the SP-3500 now.
4-WAY 6-SPEAKER, 100 WATTS: The SP-3500 is of a 4-way 6-speaker design, consisting of a large 14-inch mechanical high-cut type, high compliance woofer, a 4Y2- by 2-inch horn midrange with a sound diffuser and a pair of Multi-Direction (MD) system 4-inch cone midranges with aluminum radiators. Plus a pair of 2-inch MD system horn tweeters for the highs. Thanks to the use of specially constructed, rugged voice coils, the system is able to handle up to 100 watts in power input.
MULTI-DIRECTION (MD) SYSTEM: This is a new way of mounting individual speaker units inside a speaker system, to better reproduce in your own room the exciting liveliness or sense of 'presence' experienced in a concert hall or jazz club. The MD System is based on increasing the interaction of sound waves by criss-crossing the sounds emitted by the individual speakers. This results in a unique sound field effect unobtainable by simply widening the dispersion of sound. In the MD System, midranges and tweeters are angle-mounted so that they produce an acoustic interference fringe-a whirlpool of sound-inside the listening room.
NEWLY DESIGNED WOOFER: The newly developed mechanical high-cut type woofer of the SP3500 permits the output signal of the amplifier to be fed directly into the woofer, bypassing the crossover network. The result is a very smooth frequency response even at very low frequencies, which in turn results in extremely well-damped rich bass sound. This special design is unique with Sansui. Another outstanding advantage of this woofer is found in its high compliance. The woofer achieves a stable piston action with superior transient response even in the face of big power inputs. Quality copper coil, brass bobbin, and a cone of carefully selected pulp help to improve the speaker's frequency response as well as its sound diffusion at extremely low frequencies.
HORN MIDRANGE: Sansui engineers have placed a lot of emphasis on the midranges-those important frequencies where the vast majority of musical instruments perform-in the SP3500. One of the speakers used is a 4~72- by 2inch midrange for the frequencies from 2,000 to 6,500Hz. While the cut-off frequency of this speaker is set as low as 800Hz, it is intentionally used in the higher frequencies to eliminate the obnoxious metallic feeling unique to a horn speaker. A short-cut, exponential type die-cast from aluminum, this speaker is fronted with a sound diffuser (acoustic lens), giving it excellent sound dispersion characteristics. It also utilizes a 25mmy5 titan diaphragm for top timbre qualities.
CONE MIDRANGES: Two 4-inch cone midranges are mounted at an interior angle of 15 degrees to the front as a part of the SP-3500's MD System. Together with the horn midrange speaker, they handle the midrange sound in an 'acoustic staggering system' for greater depth and richness of reproduced sound. Each of the cone speakers has a newly developed concave aluminum dome radiator directly mounted on its voice coil bobbin. This permits a very smooth transition to the tweeters with virtually no phase agitation, and helps to improve the diffusion of reproduced sound as well. Designed to effectively diffuse radiated heat, each speaker is able to withstand big power input. The rear of each speaker is sealed with big-cavity plastic covers lined with abundant acetate sound absorbent to completely prevent woofer interference.

TWEETERS: The SP-3500 also employs a pair of horn tweeters. Positioned just like the cone midranges, the two achieve the excellent sound dispersion qualities unique to the MD System. Each tweeter is a new concept horn speaker which is responsible only for frequencies over 6,500Hz. Transition to the midranges is exceptionally smooth. Each tweeter makes use of a 19mmy5 polyester diaphragm to realize pleasant, light and transparent timbre.
NEWLY DEVELOPED CROSSOVER NETWORK: The SP-3500 is equipped with a high-performance LC type network utilizing an ideal E-type ferrite core and a printed circuit board design for greater reliability. In addition, it is provided with level controls for the midranges and tweeters. Of a unique 3-step (SOFT, NATURAL and CLEAR) 'tap-down' switch design, these permit accurate level control and are relatively free from the faulty contact and performance deterioration so common to the conventional resistor-type attenuators. They permit selecting the tonal quality best suited to the acoustic condition of the room or the listener's preference.
BASS-REFLEX TYPE CHIPBOARD ENCLOSURE: The speaker enclosure adopts adapted bass-reflex design, making use of two filled pipe ducts and combining the advantages of both the air suspension and bass-reflex designs. It completely avoids any unnatural increase in sound pressure at low frequencies, effectively prevents unpleasant 'cabinet resonance', and offers a flat frequency characteristic and a very low distortion factor. Manufactured of solid chipboard and covered with open-pore finished natural walnut, the rugged enclosure is able to reproduce the heavy rich bass of a pipe organ or any other instrument.
CURVED KUMIKO FRETWORK GRILLE: The SP-3500 is graced with a beautiful, hand-carved 'Kumiko' fretwork grille like other Sansui speaker systems. The difference here, however, is that it is curved for still better appearance and a noticeably better sound diffusing effect. It adds more than ever to the decor of any room.
PUSHBUTTON CONNECTION TERMINALS: Connections are almost effortless with the SP3500, thanks to the adoption of foolproof pushbutton type connection terminals. Just push the terminal button, insert in the opening, and release the button. This system also minimizes the possibility of short circuits at the speaker terminals.

SPECIFICATIONS SPEAKER
WOOFER35cm (14")x l
MIDRANGE-1l0cm (4")x2 cone-type
MIDRANGE-2l0x5cm (4"x2")xl horn-type
TWEETER5cm (2")x2 horn-type
POWER RATING100W (peak)
IMPEDANCE 89
SENSITIVITY 96dB/W
FREQUENCY RANGE40-20,000Hz (anechoic chamber) 25-20,000Hz (normal listening room)
CROSSOVER NETWORK4-way 12dB/oct. parallel type
CROSSOVER FREQUENCIES700Hz, 2,000Hz, 6,500Hz DIMENSIONS640mm H x 450mm W x 290mm D
WEIGHT26.4kg 31kg (packed)
FINISHwalnut open pore

SP 4 Digits Series
Introduced between middle of 1960 and 1974. These are the most well built Sansui speakers.

SANSUI SP-505J speakers (JBL LE14H + LE175DLH) perfect restored by KERICK SOUND

/http://www.youtube.com/watch?feature=player_detailpage&v=M-KdA7Y9-Ew

I'll say this -----------I LOVE MY SP-3500's.

Nice! :thmbsp:

I picked up a pair at one of the local GW stores. Very nice quality cabs. Watch for surrounds that have come loose from the cones. Both of mine needed re-glued. I found them a little lite on base for a woofer that large. YMMV

Also :thmbsp: to member 4-2-7. Nice way to spead the karma.

purple1 said:

Nice! :thmbsp:

I picked up a pair at one of the local GW stores. Very nice quality cabs. Watch for surrounds that have come loose from the cones. Both of mine needed re-glued. I found them a little lite on base for a woofer that large. YMMV

Also :thmbsp: to member 4-2-7. Nice way to spead the karma.

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I have four more of these for a quad system in excellent shape. One of them has did in a small area the ungluing. They can separate right where the fabric surround meats the paper cone. It just takes a bit of water base glue like white Elmer's to fix.

I should also say not a bad track record for this. I have 13 of these Sansui vintage speakers and only one that separated in 40 years.

Sansui SP-LE8T (Re-magnetized JBL LE8T in it) polished mahogany finish by KENRICK SOUND

http://www.youtube.com/watch?v=1Bpts4WhuS0

4-2-7 said:

Sansui SP-LE8T (Re-magnetized JBL LE8T in it) polished mahogany finish by KENRICK SOUND

http://www.youtube.com/watch?v=1Bpts4WhuS0

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Geez, two Paragon's in the same room. Wow. Sound nice, even for Youtube.

I purchased 4 3500 at a estate sale. Sold one pair, glad I did. Net outcome? I'm ahead, basically my pair cost me nothing. Impressive lineage. Thanks for posting all the great info 427!

In the early day JBL and Sansui worked together on projects and distributing,repairing in there respective countries.

Quote
Established in Japan in 1947 as an electric transformer manufacturer, Sansui's early hi-fi products sounded quite exceptional, but their styling was classically Japanese, limiting their market appeal in the West. Later models were styled to be a bit more 'neutral' but still retained hints of their Japanese heritage, such as the Kumiko fretwork grilles on many of the speakers. Sansui imported JBL speakers into the Japanese market for some years, so their engineers became very familiar with JBL's philosophy of speaker design, employing cast chassis drivers, horn tweeters, serious crossovers, and acoustic lenses on many models. During their heyday, Sansui built some delightful hi-fi speakers, including...


Hear is a AK thread that proves that point.
http://www.audiokarma.org/forums/showthread.php?t=415483

4-2-7 said:

In the early day JBL and Sansui worked together on projects and distributing,repairing in there respective countries.

Quote
Established in Japan in 1947 as an electric transformer manufacturer, Sansui's early hi-fi products sounded quite exceptional, but their styling was classically Japanese, limiting their market appeal in the West. Later models were styled to be a bit more 'neutral' but still retained hints of their Japanese heritage, such as the Kumiko fretwork grilles on many of the speakers. Sansui imported JBL speakers into the Japanese market for some years, so their engineers became very familiar with JBL's philosophy of speaker design, employing cast chassis drivers, horn tweeters, serious crossovers, and acoustic lenses on many models. During their heyday, Sansui built some delightful hi-fi speakers, including...


Hear is a AK thread that proves that point.
http://www.audiokarma.org/forums/showthread.php?t=415483

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Wow, fun read.

Copa1934 said:

Wow, fun read.

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I find this interesting, basically the 3500 was designed for quad.:thmbsp:

SP-3500 4-WAY 6-SPEAKER MULTI-DIRECTION SPEAKER SYSTEM Perhaps the most timely speaker system ever introduced, this new 100 watt Multi-Direction (MD)system takes you beyond the reproduction of sound source points to an incredibly lifelike method of reproduction approximating that of an original sound field. This makes the SP-3500 the foremost system available today for the new age of 4-channel stereo.

Picture a cat, on its back rolling back and forth in the sun. That's about how I feel after reading all the goodies, thank you 4-2-7!

Later on yesterday evening I realized that my oldest boy will be rolling in for a few days, probably about dinner time. Yeah, he's like that. What that means to me, is that I cannot drag these beasts back to my lair and disassemble. If he lost a chance to listen to them it would make him very sad, I just can't do it. It's a good thing though, it'll give me another day worth of listening and futzing with placement. I should be doing that anyway.

Even so, I'm going to remove a woofer so I can peek! I want to see the guts. We love guts, don't we?

Biggles

drbiggles said:

Picture a cat, on its back rolling back and forth in the sun. That's about how I feel after reading all the goodies, thank you 4-2-7!

Later on yesterday evening I realized that my oldest boy will be rolling in for a few days, probably about dinner time. Yeah, he's like that. What that means to me, is that I cannot drag these beasts back to my lair and disassemble. If he lost a chance to listen to them it would make him very sad, I just can't do it. It's a good thing though, it'll give me another day worth of listening and futzing with placement. I should be doing that anyway.

Even so, I'm going to remove a woofer so I can peek! I want to see the guts. We love guts, don't we?

Biggles

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And spin Harbor & the Explosion for him. He will experience 80s local Power Pop and the speakers. Plus the fact PH has heavy bass tracks to play on the 3500s

Don't forget you can adjust the tone of them at the crossover.:thmbsp: