BIC Soundspan teardown and mods...

EmuMannen

Member
BIC SoundSpan teardown and maybe some mods...

Hi everyone, this is my first post after lurking around for quite some time...

Back story, I was looking for a pair of vintage floor speakers when a friend of mine suggested that I should get his pair of BIC Soundspan TPR 600. I was a bit skeptic at first because it was not what I was looking for. Anyway to make a long story short, I fell in love with the look of them and he handed them over for free so it was hard to resist.

I immediately started to look for information about these speakers but I found very little online (to my surprise). So I thought it would be a good idea to start this thread to gather some information and also to ask for some advice regarding possible mods. My friend bought these speakers new 1979 and he has been the only owner. The condition is near MINT so I am a bit hesitant to mod them but it all depends on your feedback I guess.

I guess you all know what they look like, big bulky box with a chocolate fountain on top somewhat hidden under big boxy speaker grills. Attached is a picture for the ones not knowing what I am talking about. Stay tuned...
 

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Teardown

Speaker grills are easy to detach and so is the 12" woofer. On top of the woofer is however the "chocolate fountain" assembly. The mid range speaker is hidden inside of it but the tweeter on top is quite easy to disassemble.

You get to the mid range by twisting the top assembly counter clockwise. One came loose quite easily the other one required some elbow grease. Attached are some pictures of the mid range speakers and the top assembly without the tweeter top reflector.

I also attached a picture of the bare mid range speaker sitting on top of the woofer without top assembly that usually hide it. I hope it get you a better idea of how it comes together. There is also a spacer between the woofer and mid range that I left out in the picture.
 

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Tweeters

This is a bit strange. The speakers I got was bought as a pair but they got different tweeters. I first thought something was missing from one of them but they are in fact different. One got a piece of aluminum and a thin spacer housing the membrane. The other one is all plastic.

Attached are pictures of the two with numbers if someone got additional information. I also noted that the speakers got different production codes (note the right hand corner of the markings on the bottom of the speakers).
 

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If they're anything like the one pair of these rare beasties that I've heard, I wouldn't modify them at all, beyond maybe recapping the crossovers.
 
More markings and numbers

Attached are some additional pictures of the markings of the woofers, mid range and tweeters if anyone ever look for this kind of information...
 

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The box and crossovers

Attached are pictures of the wiring, internals of the box and the crossovers hidden under the bottom plate. This is where I see some room for improvement but I am no expert on crossovers. Could someone please take a look at this and assess them. Is it worth swapping them out for something else and in that case what?

I could keep them as is but that is quite boring. The other option is to rewire them (keeping the original parts off course), make a new bottom plate with new crossovers and binding posts. The only problem is the wiring routed behind the insulation in the box. The original insulation does look like it could benefit from an upgrade but it would be hard to turn them back to 100% original after such a mod. I am looking for opinions and advice...
 

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How do they sound?

Oh, you might want to know how they sound? Let me say this, they look more impressive than they sound. But I love the look, they fit right in with the style of our home, they make a great conversational piece and the omnidirectional quality of the sound is growing on me. Don't get me wrong, these speakers sometimes sound really great but sometimes lack the edge. It all depends on what's driving them, the source and type of music.

My friend had them paired with a Sansui 7070 originally.

I got a constraint where they are placed right now (in our living room). The WAF dictate a maximum depth of 37 cm for the amplifier. This made me first pair them up with a Rotel RA-931 MkII but that didn't work out at all. Sound was too thin and I almost gave up on them, especially after pairing them with a much more powerful Harman Kardon, same weak sound.

I happened to have a Sony TA-F220 in the garage (dumped there by a friend) that I started to renovate in lack of something else to do. I didn't expect much but I hooked it up to these speakers and it is actually what has sounded the best so far (a bit of a surprise). I currently got them hooked up to a Technics SUV-570 PXS.CAP and it works OK but I got my eyes on a Sony TA-F550ES. I hope it will be a good pairing based on my experience with the cheap TA-F220.
 
Caps...

I took the time to test those 36 year old caps in the crossover today.

Left: ESR 0.12, 10.171 uF @ 10 kHz.
Right: ESR 0.55, 9.869 uF @ 10 kHz.
 
BIC SoundSpan Speaker System

Spent some time tonight scanning the original documentation that came with the speakers. I tried to upload the result but got the following message:

Your file of 1.67 MB bytes exceeds the forum's limit of 976.6 KB for this filetype.

That's a bit unfortunate so I had to attach a really low res copy (quite useless export from Mac Preview with Reduced File Size Quartz Filter applied) but feel free to page me if you want a proper copy (original scan @ 300 dpi is 18.4 MB but the compressed version is only 1.8 MB).
 

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Installation and Operating Instructions

More scanned original documentation, this time BIC SPEAKER SYSTEMS - Installation and Operating Instructions - Models TPR 200, 400 and 600.
 

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Way forward...

Feels a bit like I'm talking to my self here but here is what I came up with:

The electrolytic caps in the crossovers are 36 years old so it's probably a good idea to swap them out...

1. Change caps .

The lining in the box is loose on several spots...

2. Fasten the loose lining.

The internal wires look really cheap, probably less than .5 mm2 (20 AWG), changing caps require some soldering and the lining is already loose so why not take the opportunity and swap out the cables for new ones?

3. Replace internal wiring.

I hate the stock binding posts, mucking around the crossovers is another opportunity to actually do something about it.

4. Replace binding posts.

There are some hollow sections of the chocolate fountain, why not fill them up with some insulation?

5. Add additional insulation around the tweeter and mid range speakers.

That is my set of reasonable mods for these speakers, so lets get to work!
 
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Crossovers and binding posts

This is a fairly simple mod. The major problem is the available real estate. The crossovers are mounted on a plate in between the bottom of the speaker box and the base of the cabinets. There are about 20mm space on top of the crossover plate and only another 15mm down to the bottom of the cabinets.

This will enforce a constraint on the caps, no more than 20mm height and the real estate around the caps are also quite restricted. It also puts a constraint on the binding posts, being no higher than 15mm.

I am not planning on going crazy in any direction, not to expensive or fancy, just plain upgrades that work. I also want to keep everything as original as possible.

The original caps are 10 uF 100V. My final selection was a pair of Jantzen Audio MKT Polyester. The size is manageable and 10 uF is 160V. It's a lot of cap for the money.

Binding posts was much harder but I finally spotted a terminal cup with terminals only 15mm height. They also had connectors for crimp terminals on the back. This was a feature I really wanted to add since the original cables are soldered to the crossover. I bought the terminal cups and took them apart just for the terminals.

The solder work was quite easy. I had to work a bit to mount the new binding posts but I can revert back to the original ones without any visible damage to the crossover board (if I ever want to). I also made room for crimp terminals.

Attached are some picture of before and after these mods.
 

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Fasten lining and new cables...

The only problem replacing the cables are the part where it routes behind the cabinet lining and between the tweeter and mid range chamber in the chocolate fountain.

A lot of the staples holding the lining was already loose so I only had to remove a couple more to be able to fold enough away to replace the cables running behind the lining.

I selected new cables with an area of .75mm (around 18 AWG). Not too fat but much better than the original ones. I kept to the original color scheme. What you will need is about:

Yellow: 1m
Brown: 2m
Red: 4m
Black: 4m
Green: 5m
White: 5m

I bought an extra meter of each color just to be on the safe side. You will also need 30 5mm crimp terminals (that includes 4 in each crossover).

The best way to route the yellow and white cables from the tweeter to the mid range chamber is to cut the old wire, solder it to the new and use the old one to pull down the new one.

I also took the opportunity to fill up the hollow areas of each chamber with synthetic stuffing.

Attached are some pictures of this work.
 

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Great documentation of your hard work. Looks like you really have things moving. Hope that the end result is amazing! :thmbsp:
 
Finally!

The warm and fuzzy feeling when everything is back together and you can enjoy your hard work. These speakers should now be at least as good as new and hopefully last another 37 years to come.

And how do the sound after the mods? Don't expect earth shattering changes, sounding like a new set of speakers or anything like that, it would defy the laws of physics. The change in sound quality is however notable (verified by my wife, the former musician with much better ears than me). Especially tremble benefited from these mods. I can now for example hear every detail in high-hat and cymbals. Well worth the job. Only one mod left ... Reconstruct the foam covering the woofers around the base of the chocolate fountain.

Attached are images of the rewired upper part of the speakers and the bag of replaced but saved original parts.
 

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Great job.

I know you will get differing opinions on whether updating the "craptastic" thin gauge vintage internal wiring makes a difference. But, every time I have done it there has been a subtle yet noticeable difference to my ears.
 
Well, I noticed that simply taking something apart and putting it all back together has the effect of clearing out the cobwebs.
I read somewhere that electrons travel on the skin of the wire. Not sure if that has been proven or just another internet myth :scratch2: but I also have heard an improvement in sound when changing to new wiring.
Strip off the jacket on some of the wire. If it doesn't look fresh underneath you might want to change it.
 
Great job.

I know you will get differing opinions on whether updating the "craptastic" thin gauge vintage internal wiring makes a difference. But, every time I have done it there has been a subtle yet noticeable difference to my ears.

I personally don't think the new wires contributed much to the improved sound (probably not at all) but the old ones felt really old, tiny and fragile. So it's more of a cosmetic thing.

I don't think I would hear the difference between the old and new binding posts either. It's more of a ergonomic thing (it is now easy to fit my 2.5mm2 speaker cables).

My guess is that the new caps are what contributed the most to the improvement but every little bit might add up...
 
Speaker foam...

Time for the final mod, reconstruction of the foam covering the woofers around the base of the chocolate fountain.

I have never seen this piece up front. I don't know exactly what it looked like or how it was originally constructed of fitted. My friend mumbled something about foam and a vacuum cleaner. Maybe that's where they all went?

Anyway, I took the freedom to reconstruct something that I thought would look good. I wanted to enhance the shape of a cone to make them even more alien looking. What you need is to make a pattern and for that you need some basic math in order to calculate the shape of a truncated cone. There are online calculators for this, here is one and here is another :)

You also need some cabinet grill foam. 10mm would have been perfect but I only had 15mm for such a large piece. Use your pattern and cut out the shape for the truncated cone and glue it together with one seam in the back. (I used contact glue). And voilà! I can finally run these speakers without the boxy speaker grills if I want to. Very happy with the outcome.

Attached are pictures of the material I used, the shape before gluing it to a truncated cone and the final result. Time to kick back and relax to some great music :thmbsp:
 

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