Infinity 3000 restoration - UPDATE - now three pairs!

[leesonic]

I am restoring some Infinity 3000 speakers for a very good friend of mine. He actually has two pairs, and despite them both saying 3000 on the back, one pair is a 3000A. He bought these speakers from new, and I guess over the years, the original woofers had their foams rotted, and were replaced with aftermarket ones. Interestingly enough, he told me he did a party with these speakers, and somebody kicked in one of his original woofers. So he has two pairs, but only one of them has the original Infinity woofer, the other three are all the same as pictured below.

The two speakers shown here aren't a matching pair, he gave me the two with the worse woofer foams. The other pair (with one Infinity woofer and one replacement) has the foams just barely intact. He is going to run these at reduced volume while I refoam these ones.

I sure wish I could find him another 3000 woofer. Does anybody have any ideas on what these replacement ones are, going on the part number below? It looks similar to another Pioneer part number I have seen. My plan is to restore what he has, and see if I can find an Infinity woofer.

 

[leesonic]

Here are the woofers refoamed. The new foams are thicker than the originals, which means I can't use the cardboard "gaskets" around the edge. No matter, I think they look better without them anyway. I managed to pull the dented dust cap out with some hot melt glue on a popsicle stick.

 

[leesonic]

The crossovers have a slightly different design from the 3000 to 3000a model, owing to the midrange and tweeter level controls being transposed. Still the same cap values though.





Usually, myself and others don't advocate replacing old film caps. But since these Dayton Audio ones are so keenly priced, I went ahead and replaced them. If you believe caps have their own sonic signature, then keeping the caps all the same brand seems to make sense. The cap for the midrange is nearly $1 per uF, but I feel that it's worth it, since it's directly in the signal path, as are the ones for the tweeter (which are cheaper as they are smaller).





Woofer wiring was upgraded to 14 gauge, and soldered on.



The holes for the woofers seem to have been drunkenly drilled on a Friday afternoon. These got plugged with glued in popsicle stick pieces, smoothed over, and new holes drilled.

 

[leesonic]

The tiny layer of paper that got pulled off when I removed the dent from the dust cap, this got fixed with some Parts Express speaker paint. Now, it's almost impossible to tell which one was dented.

 

[M Sampognaro]

Are the woofers unfiltered? No coil or other crossover component?

 

[leesonic]

Are the woofers unfiltered? No coil or other crossover component?

Yup. Same as a lot of Advents, Genesis, ARs etc.

 

[M Sampognaro]

Would the sound quality be improved be adding a coil to the woofer?

 

[cunningorb]

@leesonic I have a pair of these I just did woofer refoam on. Great job on yours! You clearly went the extra mile for the wow factor when people see them.

Where did you source your capacitors?

 

[leesonic]

@leesonic I have a pair of these I just did woofer refoam on. Great job on yours! You clearly went the extra mile for the wow factor when people see them.

Where did you source your capacitors?

I got them from Parts Express.

 

[leesonic]

Would the sound quality be improved be adding a coil to the woofer?

I am neither a speaker designer, or drive unit engineer. But when Celestion designed the SL-6 speaker, they used some laser scanning to see what the diaphragms of woofers and tweeters were doing. They found all kinds of things : woofer surrounds ringing like a bell, dust caps bouncing on their glue joints, and tweeter domes showing horrendous breakup in their normal operating frequencies.

Why I am telling you all this? Well, when they scanned woofers, they found that the radiating area of the diaphragm or cone got smaller and smaller with increasing frequency, eventually just being a small area around the center. This is why midrange drivers are smaller than woofers, they don't need all this area. So, with the Infinity woofers, they have a heavy lump of what looks like bitumen damping in the center of the cone. Since this is where the midrange frequencies would be coming from, I think this effectively cuts off the upper frequencies that the woofer can reproduce.

But again, I am neither a speaker designer, or drive unit engineer.

 

[leesonic]

Here are the woofers from the second pair of speakers. As mentioned above, my friend only had one Infinity woofer out of four speakers.



What is not immediately obvious from the pictures below is that the edge of the woofer was very flaky, like the layers of paper/cardboard were separating. What I did was, I carefully painted the edge with a 50/50 mixture of wood glue and water. After it dried a day or two later, the edge was much stiffer and all the separations were now together. I didn't take pictures of it, but I also masked off and painted the frame, as removing the old surround pulled away a lot of the paint.

 

[leesonic]

But what's this? These aren't my friends speakers!

I went and bought a pair of these for myself, I drove a 150 mile round trip to get them. Before I gave my friend back his speakers, I sat and had a good listen to them. I heard some things I had not heard or not noticed before. This is in music that I've listened to for the past 30 or 40 years. This is why you can't just have one pair of speakers... or 12...

As you can see, the original woofers have long gone, and in their place are a pair of Radio Shack 12" poly woofers. They work though, as do the other drivers.

 

[leesonic]

I managed to find some Infinity woofers on eBay. They needed refoaming, but don't they all? One of them had some staining on the cone.



I found some light gray paint at my local Hobby Lobby store. In the picture below, you would never guess that the one on the left was the one with the staining, would you?



The screw holes for the woofers were just as bad, if not worse than the ones I worked on for my friend. Again, I glued in some pieces of popsicle stick, when the glue dries I will smooth things out with wood filler. One cabinet appears to have a crack between the woofer and tweeter hole. This won't be a problem, as I plan to put a brace there.

 

[leesonic]

Adding a brace from front to back. This will strengthen the cabinet where there is a crack between the woofer cutout and the tweeter. I also added a small scrap of wood to strengthen between the midrange and the tweeter.





Filling some holes, and giving the baffle a fresh coat of paint. I wish the textured black spray cans I had been using in the past worked better.

 

[leesonic]

Sanding the cabinets down for their first coat of Tung Oil.



First coat of Tung Oil applied. It's a shame the stain I put on the wood filler didn't take at all. I will just get some dark brown paint at the hobby store, it's not like the wood filler would have the wood grain pattern on it.



Second coat of Tung Oil.

 

[leesonic]

Crossovers are easier to restore when they are out of the cabinets. One of these was loose, and the other one didn't take much persuasion to get it out. After reworking, I drilled four holes in each corner, and hot melt glued them in, using some screws to hold them in place. Not immediately obvious, but I replaced the terminals with some gold plated ones from Parts Express. These allow thicker speaker wire to be used.

Crossovers are also easier to repair when your cat isn't sticking it's beak through the hole where the crossover needs to go...

 

[leesonic]

And here they are all finished, sitting next to my JBL L100s.

 

[MFRD]

Great job! Well done!

 

[RVT1K]

Crossovers are easier to restore when they are out of the cabinets. One of these was loose, and the other one didn't take much persuasion to get it out. After reworking, I drilled four holes in each corner, and hot melt glued them in, using some screws to hold them in place. Not immediately obvious, but I replaced the terminals with some gold plated ones from Parts Express. These allow thicker speaker wire to be used.

Crossovers are also easier to repair when your cat isn't sticking it's beak through the hole where the crossover needs to go...

View attachment 3532722View attachment 3532723View attachment 3532724

There's more than a little bit of crazy in those eyes!!

 

[leesonic]

Something I noticed while sitting close to these speakers. It would seem like the midrange is out of phase with the woofer, you can certainly hear some of that weird phasing thing (I don't know how to describe it better) going on, especially if you tilt your head so one ear is close to the midrange and the other close to the woofer. I always thought that 6dB/octave crossovers didn't need the midrange to be reversed. Maybe @Pete B or one of our crossover experts could shed some light? I did pull the midranges out and check my wiring, I seem to have wired them up correctly. But I am not sure what's going on inside the sealed plastic enclosure for the midrange. I did swap the polarity around, and checked that the "out of phase" effect had gone away. I'll see how they sound...