Sylvania Stereo Cabinet Restoration

[hjames]

Since the existing amplifiers are not high power,
if you want to just set a pair of existing bookshelf speakers in there,
suggest you look for highly efficient speakers in cabinets ...

 

[AudioSpartan]

If I have two 4 ohm tweeters wired in series is that an 8ohm load? If I replace with a single tweeter I need to know what I’m looking for.

 

[gdmoore28]

Ok, so I’ve got a new DMM and I’ve been checking things out. The readings I’m getting from the woofers are 7.5 ohm and the tweeters are 3.7 ohm. So am I right in assuming that those are eights and fours?

Yes. You have an 8 ohm woofer, and two 4 ohm tweeters wired in series for an 8 ohm load. So you need to buy an 8 ohm woofer and one 8 ohm tweeter.

GeeDeeEmm

 

[AudioSpartan]

I've been reading A LOT and watching tons of videos on speaker response and crossover design. I came up with a design that might work fine for me. I know it's not perfect but this is my first crossover and I think the cheaper speakers are working against me.

 

[triode17]

two 4 ohm tweeters wired in series for an 8 ohm load

I beg to differ. Look at the schematic. They all look to be in parallel, which is even weirder! Can someone explain THIS?

 

[gdmoore28]

I've been reading A LOT and watching tons of videos on speaker response and crossover design. I came up with a design that might work fine for me. I know it's not perfect but this is my first crossover and I think the cheaper speakers are working against me.

I think you'll be fine with that design. The "silkie" tweeter will easily cross at 1200Hz. You may have to fine tune the crossover a bit if that 800Hz hump is aggravating. In that case, you will need to insert a notch filter to bring it down.

GeeDeeEmm

 

[AudioSpartan]

I beg to differ. Look at the schematic. They all look to be in parallel, which is even weirder! Can someone explain THIS?

Haha I know. After looking at the schematic closely and comparing it to what I pulled out, I’ve realized it’s either wrong or someone swapped the speakers already. My money is that it was a basic schematic they pasted into many models.

 

[triode17]

Haha I know. After looking at the schematic closely and comparing it to what I pulled out, I’ve realized it’s either wrong or someone swapped the speakers already. My money is that it was a basic schematic they pasted into many models.

So they ARE in series? That would make more sense. 8 ohms (Woof) parallel another 8 ohms=4 Ohms, single ended. BTW, I love the cabinet with the arches, looks great.

 

[KentTeffeteller]

Thanks for the complements. Here are some inside pictures. I’ve ordered legs, vintage fabric, and NAL tweeters (the soft dome type). At $15 dollars each, that should open up the top end, I hope, and answer some questions I’ve had about those tweeters for a while. I’m going to leave the woofers for now. I don’t want so put too much money into this. It’s just going to be for in room listening and maybe parties.

This console is never going to have modern full range treble. And likely is treble and low bass limited by design. Don't expect much over 16,000 Hertz. It's designed to sound as good as it can given what it cost new, and designed to work together as a integrated whole. And it's nicer than all but the higher end models from the best manufacturers.

 

[quiet]

Since the existing amplifiers are not high power,
if you want to just set a pair of existing bookshelf speakers in there,
suggest you look for highly efficient speakers in cabinets ...

The amp is in the way. See post 11

 

[hjames]

The amp is in the way. See post 11

Ack - why isn't the amp hanging in the middle where it belongs!
I think I'd look into moving it somehow - its a great looking cabinet, otherwise!

 

[KentTeffeteller]

The sound is all mid range. I have stacked advents and love the bright sound and heavy punch. I know the cabinet won’t sound like those ever but I want it to be good enough for me to want to power it up every once in a while.

It can't or never will sound like one pair of Advents let alone two pairs of Advents. No console ever made can! Speakers which can sound closer to what you want and that a low watt tube amplifier can drive are bigger than this console are, and are very expensive and cost more than double the whole console did then alone. This console is not able to drive Advents. And is bass and treble restricted. The console is good for what it is and what it can do. But it isn't going to reproduce 20,000 Hertz, or anything below 100 Hertz. Try 15,000 Hertz response at very best. Low response is filtered by design to keep acoustic feedback from being a major problem with the turntable in the same cabinet. Facts are facts. This is less than a 10 watt/channel amplifier. It like all but a very small handful of factory built super dollar consoles is what it is. Want more, look at a very high end $1300 up Fisher or Magnavox Concert Grand.

 

[quiet]

Ack - why isn't the amp hanging in the middle where it belongs!
I think I'd look into moving it somehow - its a great looking cabinet, otherwise!

I thought you would say that.

 

[AudioSpartan]

I understand what you are saying, if you want to hear to Advents, listen to Advents. I know this thing won't be hifi or even close to it, I just want it to sound good enough that I won't just turn it off in favor of other speakers. I am keeping it mostly for aesthetics but I hate for it to just be a shelf my Sansui sits on.

 

[mashaffer]

Before replacing the woofs which I assume are running open backed I would make up enclosed backs for them. With a proper crossover and decent sized sealed enclosure they might surprize you.

If at that point they just need a bit more bottom end a separate powered sub might be the ticket as it would keep the very low frequency excitations out of the main cabinet. Also you can use the rear chambers as bracing to stiffen up the cabinet and damp resonances. Sometimes it is cabinet resonance more than speaker faults that color the sound in consoles.

 

[Katalyst]

Any progress?

 

[AudioSpartan]

Sorry guys, I've been super busy with work and waiting on parts to come in. For some reason, my phone has not been able to post so I'm finally doing it on my laptop. Speakers are in and sound amazing! Crossovers are built and installed (triple checked my order and still missed two caps). Grill cloth is on and so are the legs which were totally the wrong color, so I had to strip them down and restain too. Still have some connections to solder and I've ordered a new 60W iron because the 20W one from my childhood wasn't cutting it. Other than that, I'm down to finding where all these screws I took out go and a little more poly work. Oh and put the name plate back on the front. Here are some pictures.

 

[gdmoore28]

Very nice, A.S.!!!!!! I'm so thrilled that you found a good speaker/crossover combination. And the grill cloth simply looks great. Good on you for persevering with this project despite the prevailing doubts that you could make it work. Wish I could hear it.

GeeDeeEmm

 

[quiet]

Well, I will say that I am impressed. I will admit I was concerned about the woofer. Only because they get no help from the cabinet do to completely open design. I thought it might require moving the amp to center and closing in the speaker cavity to facilitate a conversion to infinite baffle.
Wow, start to finish in 5 weeks and it works.
How cool is that?

 

[gdmoore28]

Well, I will say that I am impressed. I will admit I was concerned about the woofer. Only because they get no help from the cabinet do to completely open design. I thought it might require moving the amp to center and closing in the speaker cavity to facilitate a conversion to infinite baffle.
Wow, start to finish in 5 weeks and it works.
How cool is that?

Well, we all had our concerns, didn't we? I could never get a 10" woofer play nice in a two-way configuration - even with a tweeter that nice. But Henry Kloss did it repeatedly using only a cap as a crossover! Shows what I know about speaker design.

Somehow A.S. managed to do it to his satisfaction and my hat's off to him. Sometimes a man just needs to DO IT and go from there.

GeeDeeEmm