Dynaco A25 woofers

[Finjima]

I Just picked up a set of A25's that came in their original box's, A Dynaco 400 amp and a dynaco Pat 5. all together. for a reasonable price. Now about the speakers. the woofers are not the ones that originally came with the speakers, they were not hooked up and just sitting in the cab. they would not fit in the opening and I think the owner previous to the person i picked this up from had tried replacing their blown woofers and hit a road block and gave up.
So I got my wood file out and got to work and with some careful work they now fit. and are now hooked back up. now I need to ID them to find out how to sort out the crossover. these are the original 1 1/2 inch 4/8 owm tweeters with the 5 uf cap. now finding info on these woofers has been problematic, in another thread on woofers I seen one that looks like mine and someone suggested its from a A25 XL and made by scanspeak with the numbers 7883 on it. Can this woofer and tweeted be mated together will I need a different size cap for it or a coil?

Here are some pics!!!

 

[Finjima]

Now on the cabs. these came with some pretty roached out box's and one speaker and box had seen some water damage some time in the past. one speaker is in vary good condition on the finish, and the other is the same in condition except for the lower left corner of the speaker where the water swelled the corner and the seam split and dried separated. with the finish damaged also. Ill need to restore the finish on both speakers, clean up some light scratches and get them shined all up nice and pretty. I replaced the binding posts with new ones from rat shack and look like they will hold up good.
Now repairing the water stains leaves me with some questions on what to use for the finish and about the seam, well im temped on leaving it, but i would like a good strategy for cleaning that crack out and pressing that corner back together. or i can leave it the way it is.

Pics!!

 

[phansen39]

Did the whole corner seperate or just the veneer?

 

[Finjima]

the veneer is not separated mostly, just the particle board underneath swelled up and dried with the corner seperated

 

[phansen39]

Cut into the split with a fine/thin saw. Get the edges as parallel as possible. Glue and clamp.

 

[Finjima]

I have one of these, a fine tooth thin hand saw, will be tricky around the corners by the front and back edge veneer pieces. may have to carefully peal them back. Ill need to pick up some clamps. ok, i am saving this till last to do. ill work on identifying the woofers and figuring out what cap i should use in the cross over. I checked the ohm on the 2 woofers, one measured 5.2 and the other was 5.4. (i measured them in circuit, didn't disconnect the wire)

 

[gdmoore28]

The A25 manual I found says that the system is rated at 8 ohms. The readings you got from your replacement woofers are exactly where they should be for a typical 8 ohm speaker. No need to alter your crossover network unless you want to replace the capacitors with newer units of the same ratings. Just install your replacement woofers and start enjoying what you have. (Since we have no idea what your replacement woofers are and have no T/S parameters to work from, altering the crossover would be purely guess work.)

The cabinet damage is another issue. As you've been told elsewhere, unless the swelled portion of particle board is removed, there is no chance that the panels will pull together. So, you have nothing to lose by going at it with that saw you have, then trying to clamp it back together. Be forewarned, the panel may break if it's put under much pressure with the clamps. So, I would undercut the intersection just a bit. (i.e., remove a little more than you think is necessary.)

Good luck, and keep us up to date on your progress. We'll all learn something from your project.

GeeDeeEmm

 

[Finjima]

About the woofers. as of now they are unknown make and model and sound recessed when I hold my ear to the woofer while playing. I am not sure these are from a Dynaco A25 XL even. What if they are some random 10 inch some one got their hands on?

 

[gdmoore28]

Explain a little more what you mean by "recessed." (And I'm assuming that you have them installed in the boxes, right?) Does it not produce adequate bass response? Is it quieter than the tweeter? Does it have a 1/2-round rubber surround, foam surround, pleated cloth surround? Do they make any funny noise when you play them? How do the spiders look? Have you wired them in correct polarity? Did you connect them to the correct wires on the crossover?

You can help us a lot by looking for any other numbers on the speaker frames and on the back of the cones. And we need good pictures of the woofer from the front, and closeup pics of the spider, as well. We're shooting in the dark on this one.

(Apologies to those who noticed that I played fast and loose with my grammar on this one. I've worked today, I'm exhausted, and really don't care that much right now.

GeeDeeEmm

 

[Finjima]

Ok take a moment and breath, pop a beverage and relax its friday!! and thanks for helping out.

OK Rubber surrounds the dust cap is flat with a sheer black material
if you google AFTERMARKET Vintage DYNACO A25 generic 10" WOOFER you will go to whats that site and there are more listing pics there of same/similar woofer
ok back to the sound, compared to another speaker's woofer in my garage (where I'm working on them at) these seem quieter, lacking dynamics and bass.
yes they are installed in boxes after i had to modify the box to make them fit. id say not much quieter than tweeter. I wish I could compare them to another a25 with the right drivers so I know I'm not being mental about what I'm hearing

a aside here I'l introduce myself I live in florida and decided to make a hobby with vintage stereos and speakers. I been interested in this for a while but recently got off my butt and got some equipment. and I want to build a small electronics lab, I remember as a kid pooring over the sears catalogs drooling over the stereo equipment, I used to play dad's record player and stereo and when I got to collage I had a okish system I used to crank up all the time with (beer induced volume control) later on I moved around a lot and at one point I gave up the stereo stuff. but now I'm back, picking up a Pioneer sx 737, a Yamaha cr 640 and a kenwood kr 4200, and the kenwood need a recap and rebuilt power supply, I'm sure they all need to be recapped actually. In the Garage i have a pair of RTR 600D speakers, 4 feet tall 4 Ohm and louder than I care to play them at, to bad so sad was going to set up the a25's in the house but I'm not happy with em yet

 

[Finjima]

and back to how they are wired. I went with the red dot on the speaker for the red wire (as you can see in last pic above). and here on the cross over you can see the terminals the red wire connects directy to the lug (thats the red lug on the back side of the speaker)

 

[gdmoore28]

Well, everything looks correct. Are there air leaks around the woofer? If so, very weak bass would result.

How old are you? The things you describe puts you back maybe just after my teen years. I'm 63.

GeeDeeEmm

 

[Finjima]

I'm 50 , I remember dad's old player was from around lets say 67 71ish, it was the old stereo with built in record player 8 track, you know I'm not really sure what the hell it was, ill have to ask him, I remember playing roy orbison over and over. Later on I got my own record player with built in speaker and I played records all the time, Haha your going to laugh at this, one day i was nuts over the village people and was playing I think YMCA or macho man. i forget like over and over and over. just being a kid and apparently it was driving dad NUTS and he walks into my room and smashes and broke the record player. I can't recall if I laughed or cried when he did that then, but its funny as hell now.

there could be leaks from the seal on the woofer, I wasn't trying to hard on sealing . And from what I been reading about the original seas woofer it was designed around a weak magnet and that too strong a magnet would produce weak base also. This woofer has a good sized magnet structure

 

[CohibaJoe]

I Just picked up a set of A25's that came in their original box's, A Dynaco 400 amp and a dynaco Pat 5. all together. for a reasonable price. Now about the speakers. the woofers are not the ones that originally came with the speakers, they were not hooked up and just sitting in the cab. they would not fit in the opening and I think the owner previous to the person i picked this up from had tried replacing their blown woofers and hit a road block and gave up.
So I got my wood file out and got to work and with some careful work they now fit. and are now hooked back up. now I need to ID them to find out how to sort out the crossover. these are the original 1 1/2 inch 4/8 owm tweeters with the 5 uf cap. now finding info on these woofers has been problematic, in another thread on woofers I seen one that looks like mine and someone suggested its from a A25 XL and made by scanspeak with the numbers 7883 on it. Can this woofer and tweeted be mated together will I need a different size cap for it or a coil?

Here are some pics!!!

These are from my A25...Not sure when your set was made. Maybe production change during it's time?

 

[gdmoore28]

I'm 50 , I remember dad's old player was from around lets say 67 71ish, it was the old stereo with built in record player 8 track, you know I'm not really sure what the hell it was, ill have to ask him, I remember playing roy orbison over and over. Later on I got my own record player with built in speaker and I played records all the time, Haha your going to laugh at this, one day i was nuts over the village people and was playing I think YMCA or macho man. i forget like over and over and over. just being a kid and apparently it was driving dad NUTS and he walks into my room and smashes and broke the record player. I can't recall if I laughed or cried when he did that then, but its funny as hell now.

there could be leaks from the seal on the woofer, I wasn't trying to hard on sealing . And from what I been reading about the original seas woofer it was designed around a weak magnet and that too strong a magnet would produce weak base also. This woofer has a good sized magnet structure

'


That's a funny story. I'm sure my parents almost went crazy because of the same antics. In my case, it was "North To Alaska" and several other songs that were popular at the time. To make matters worse for them, I became a drummer. My dad got so sick of it that he went to a local arsenal that was still disposing of WWII equipment at that time, and bought two tank crates made of oak. He put the two of them together, and built a roof and that became my "drum room." I sweated in there practicing drums thru all seasons, and later on my band practiced there.

I'd make a gasket from foam rubber to make sure that woofer is sealed perfectly. Once that is done and you still have weak bass, that speaker is just not going to be a good replacement.

GeeDeeEmm

 

[gdmoore28]

These are from my A25...Not sure when your set was made. Maybe production change during it's time?

That's one of the speakers that started an audio revolution, Joe. It oozes quality from a-z, doesn't it?

GeeDeeEmm

 

[Finjima]

I totally forgot Johnny Horton, Yes sir we has some of his also and North to Alaska, Sink the Bismark, Battle of New Orleans, I ate that S#$t right up, I'm listening to Sin the Bismark now, I recall that was my favorte

 

[WaynerN]

They are not A25 or A25XL woofers. Those woofers were either made by SEAS or Scan-Speak. The woofers you have remain "unknown".

The original cross-over network for the woofer has no components to it. The woofer would simply roll off naturally, Unfortunately, the box and the slot (known as an Aperodic Enclosure) is tuned to the woofer (and its specifications). I believe that the correct one is the one shown by CohibaJoe.

Wayner

 

[sax6]

Look for a real 25 TV EW woofer on that auction site >>>> and let them be real A25.....

 

[Finjima]

before i give up on these woofers I'm am going to work on sealing the woofers. if that works ill upgrade the cap, then ill work on the cabs.