Cheapo Sansui S-1000 upgrade

[Weber]

These speakers aren't great or even good. The bass though lacking output is pretty clean and strong given the sealed cabinet design. I got them for free. Yes they were on the side of the road and the cabinets are in pretty decent shape minus some minor scuffs and pealing fake veneer. They feature 12" woofers 4" midrange and 3" horn tweeters.

Design goals: Upgrade all components with higher quality modern ones. Increase total output and much better sound quality. Do something with the finish, either paint them or new veneer. Everything will be modelled in WinISD but I have no way of testing them, so to simplify the process the best I can, I opted for a sealed back midrange design and then simply replace the existing paper cone tweeter with something along the lines of a textile or silk dome. And since I have no measurement equipment to speak of, I'll simply be relying on my ears. Perhaps I can use my listening mic that came with my Yamaha receiver to get some sort of idea of the response but I will have to play around with that idea. The cabinet is 2.73 cu ft and I found several potential woofers, I will just need to model each one to see what could give me the best results.

I made a quick mock up of a before and after just to get idea of what they could look like.

[Chris Roemer]

No reason not to get the tweeter and mid as close together as possible.
Cab volume is meant to be INternal volume. Once you pull the woofer, you should be able to estimate the wall thickness.
You could go sealed if your intention is to leave them on the floor (generally not the best idea). If you're raising them up off the floor (stands) and away from the wall, I'd vote for a ported design (or you'll end up wanting to run a sub, anyhow - that would be a shame w/10" woofers).

[Weber]

No reason not to get the tweeter and mid as close together as possible.
Cab volume is meant to be INternal volume. Once you pull the woofer, you should be able to estimate the wall thickness.
You could go sealed if your intention is to leave them on the floor (generally not the best idea). If you're raising them up off the floor (stands) and away from the wall, I'd vote for a ported design (or you'll end up wanting to run a sub, anyhow - that would be a shame w/10" woofers).

I have no way of moving the location of any drivers. I'm using the pre-existing holes and the front baffle the way it is. This is only an upgrade project, not a complete renovation. I wish I could do more, but I live in a small apartment and do not have any power tools.

[Weber]

UPDATE: I just ordered these drivers today:

Dayton Audio TD20F-4 3/4" Soft Dome Neodymium Tweeter 4 Ohm - https://www.parts-express.com/Dayton...ableshopping=F

Goldwood GM-65/8 Sealed Back 5-1/4" Midrange 8 Ohm - https://www.parts-express.com/Goldwo...ableshopping=F

And I will have to also solder them because the originals are soldered. But I think these drivers will turn out well. I'll post pics once I've installed them.
Oh and I might have to do something about the crossovers because there just seems to be a couple capacitors.

[Brian Steele]

You'll definitely need to do something about those x-overs, and the original x-over was designed with the original drivers in mind. Change the drivers and the x-over needs to be changed accordingly, even if the drivers are the same size.

[Geoff Millar]

I had a look at these on Google; there's a photo of the back of the speakers which says that the crossover points are 3,500 and 9,000 Hz. That seems remarkably high for a 12" woofer. The S-1000 woofer is labelled on its magnet as 7 ohms and 25 watts but I can't find any other info or specs on it.

If you use the original crossover, the Goldwood would have to cover the 3,500 to 9,000 Hz band, which might be a struggle for a mid-range driver, depending on its quality.

Geoff

[Chris Roemer]

To help suggest an XO, we'd really need to know something (ANYthng, really) more about the woofer - other than it's 10".

[Weber]

Ok a little update. I purchased the tweets and mids, however the new tweeters are too small so I will need to send them back. The holes are an odd size so I will need to get full size tweeters and open the hole up some. See attachment for hole size. I'm also currently looking for a solution for the crossovers. Might just assemble some but without any measuring to at least get some decent crossover points.

[Chris Roemer]

So ... these have already had all the drivers replaced?
Your before/after mock-ups show a GIANT 12"? (squarish frame) woofer and a ribbon? (square) tweeter.
It LOOKs like there's already a 3" cone tweeter in there - but I can see on the baffle the impression of a square (orig. ribbon?) frame.

What's the internal volume (dims.) of your cabinet?
Why not make a rectangular "plate" (out of something like hardboard (Masonite) and cut a hole in it to use your TD20s?

[Weber]

So ... these have already had all the drivers replaced?
Your before/after mock-ups show a GIANT 12"? (squarish frame) woofer and a ribbon? (square) tweeter.
It LOOKs like there's already a 3" cone tweeter in there - but I can see on the baffle the impression of a square (orig. ribbon?) frame.

What's the internal volume (dims.) of your cabinet?
Why not make a rectangular "plate" (out of something like hardboard (Masonite) and cut a hole in it to use your TD20s?

I have not replaced all drivers yet. Just the mids. There aren't any after pics yet, the first image was a 3d rendering of my design goals. I'm keeping the 12" woofers for now. And there are square plastic covers around all the drivers. The tweeter one is strange because it's rectangular with a mesh screen that covered a good portion of the driver making it look like a ribbon when in fact it's just a paper driver. The size of the tweeter cone is 2.21 inches with overall being around 3". The internal volume is 2.2 ft^ᶾ.

I have no way at this time to cut or make anything new. I only have a drill with some bits for grinding/rasping so i'm only going to open up the hole a bit for the new tweeters(already ordered)

[Chris Roemer]

(kinda like pulling teeth - but... ) so you plan on keeping the old (no name) woofers, which were closed box but you want to port them (w/out any T/S parms)?
And you already sent back your TD20s and ordered something else - like what?

[michaelmoran]

OK, am late to thread, but this is what I would do.

Use cabinets to build Wolf's Zingers. See design: http://techtalk.parts-express.com/fo...8-2-way-design

I would buy this to reduce size of woofer cut out from 12 inches to fit 8 inch woofer: https://ak-audio.com/products/12-to-...7a98d8db&_ss=r

Use midrange cut out for tweeter: https://www.parts-express.com/Peerle...6-Ohm-264-1460

This is woofer: https://www.parts-express.com/Dayton...woofer-295-484

Use tweeter hole for port. Use foam poster board as needed to make tweeter and port fit. if you need to

Not sure volume of your boxes but may have to adjust. Use a box with sand to reduce volume of your boxes.

Simple crossover so crossover parts will not cost that much. I would use cheap poly caps and cheap resistors, so only real expense of crossover parts will be 2 coils, and only one is a pretty big coil.

[Weber]

Not only are you late, but you don't seem to understand the design goals. I'm referbishing these old speakers not building new ones.

[michaelmoran]

Another option would be these bad boys:http://techtalk.parts-express.com/fo...rs-based-3-way

They use a 12 inch woofer. For the tweeter you can use foam board to make things fit. Note post 33 on modification of crossover.

[Weber]

(kinda like pulling teeth - but... ) so you plan on keeping the old (no name) woofers, which were closed box but you want to port them (w/out any T/S parms)?
And you already sent back your TD20s and ordered something else - like what?

I'm keeping the sealed design. And this is what I ordered yesterday
GRS 1TD2-8 1" Designer Dome Tweeter 8 Ohm https://www.parts-express.com/GRS-1T...ableshopping=F

3-Way 8 Ohm 800/5,000 Hz 100W https://www.parts-express.com/Crosso...ableshopping=F

[Weber]

Update: Removed old crossovers, and built one of the new ones. Cut wires for both of equal length than soldered them on one of them. It occurred to me that I didn't think about wire for the crossovers, and all I had on hand was some 12 gauge which is overkill but it will work just fine. I was right in the middle of opening up the tweeter hole when my cordless died so I will have to wait for it to charge up real good.
I also cut some isolation pads from some foam that I had for the crossovers.

I also took a pic of the sticker on back. It seems my new crossovers are a close match.

[Chris Roemer]

Only your mid has F/Z data avail.
Here's the simmed FR w/your 3-way XO (brightest line - it's yellow actually; I'm guessing at your coil values, but they're educated guesses) for your mid.
The bottom end rolls off around 450Hz (w/a bit of a "honk" around 500Hz due to an inherent +9dB peak before rolloff) and the top extends to near 8k, probably w/some shrillness near 7-8k where the mid and tweeter overlap. (Your isolation pads won't help with that.)

If your woofer IS 89dB, then the mid should pretty well match - level wise, but NO BSC.
Guessin' your box is about 2.2cf internal. That pic of the cab back would have been lots of use to peeps trying to help you for the last 2 wks.

You MIGHT be able to tame some of the harshness near the ends of the passband by running a 15ohm resistor across the mid's terminals (up to 20w possibly?).
With some XO mods (taking the mid down about -5dB and the tweeter down -6?) you could probably gain some BSC - requiring you to get those largish boxes up off the floor.

Are you sure those (foam?) surrounds on the woofers haven't rotted? VERY unlikely that surrounds on an AS woofer that's 30-40yrs old aren't ready to fail. (Many would be ripped by now - and some totally disintegrate!)