Need some tech advice to salvage subwoofer

[azrockitman]

It is tempting....It would be cool to upgrade this on my own.

I removed all screws from the driver, but it's also clearly glued.  Not sure what to do to pry it off.  The amp plate removes easily in back.  I decided to leave it alone, unpowered, until morning to avoid electrocution risk.   

I suppose I'll try a gentle putty knife maneuver around the edge of the driver in the a.m. to see if that pops it loose.  If it will come off, it should be a very simple replacement. 

BTW, I mistyped earlier....the amp is 150w, not 250. 

[Grainger49]

Your plate amp is solid state.  Speaking of a "standard" power supply, not a switching power supply, few of them have high voltage in the power supplies.  Look at the voltage rating of the power supply capacitors.  If they are 60V or lower, jump in.

A putty knife or a big flat bladed screwdriver would be good tools to gently pry the sub loose.

[azrockitman]

well, that was simple.  Driver popped right out. 

Sub box is un-ported/vented.
14.25" tall,
19.625" wide
13" deep.
These are outside dimensions.  Wood is .75" thick.  Fiberglass-type insulation inside. 

The subwoofer driver measures 12.0625" wide, outside edge.  It drops into a hole cut-out measuring 10.875".  Eight screw holes on the driver.
The specs on the amp and crossover show a working frequency range from 20Hz to low pass filter setting up to 125Hz
It has a continuously adjustable low-pass filter from 60Hz to 125Hz.  The only impedance number I can find is 10ohms....? 

[4krow]

  So far so good, 10 ohms would not be an unusual number.  My math GUESS is that cabinet is a little over 1 cubic foot. Now I'm thinking that a suitable driver would have the needed parameters to work in this size enclosure. I usually just go to the Theil/Small specs of the driver, where a useable sized enclosure may be given. So far, you have an idea of the impedance,driver size, enclosure size,frequency parameters(not necc frequency response) and power handling of the old driver. Using just that much will get you a good start down the right path. Spelling might be off, but Madisound sound has a number of possibilities that will also help you narrow down your choices. Then of course the price limits will further dictate the rest.

[Grainger49]

I'm curious, did it have two or four wires going to the woofer?  If four it has a servo circuit.

[azrockitman]

Greg;  thanks I'll check it out! Thanks!

Grainger, just two wires. 

Thanks guys.

[earwaxxer]

Yep.. like Granger says .. some voice coils are wired in such a way that you can power them with a 2 channel amp. 2 - 4ohm voice coils. Easier on the amp than a 2 ohm load. Its good to buy the amp and driver together to maximize the compatibility. I dont have a dual voice coil driver. Its something to consider though.

[2wo]

I get 1.5 cf, that is a little big for the driver I was thinking of.

I bet if you call PE or Madisound, Hey I got this box with this amp, looking for music, explosions, not so much. they will hook you right up

 they're  tech guys, they live for this ...John

[azrockitman]

I'll be making some calls tomorrow.  Thanks!

[Paul Birkeland]

I'm just sayin...

dust cap

[Grainger49]

I had  no idea that you could buy them. 

Interesting!

[4krow]

It is certainly easier to reduce the volume of the box than to increase it.

[azrockitman]

I'm just sayin...

dust cap

gosh, $1.68?  that's far too cheap and easy.   

[4krow]

I'm not sure if this makes a difference, but I have seen some dust caps that allow air flow, while others don't. It probably has something to do with a vented pole piece, point being replace like with like.

[earwaxxer]

Cool thing about PE drivers - they give specs on each driver on cabinet size, ported/sealed or both, etc. Frequency response, efficiency, power handling etc. What was iinteresting for me, was that my HSU 12" sub that I bought many years ago (a round one) had a very efficient 12" that produced low bass (down to 20hz) very well, but broke up and got muddy in the 30hz range. I still use the same cabinet today, have cycled through several woofers in there. What I have 'settled' on is a good high power handling driver that goes 'low'. I havent measured it, but prob rolls off in the low 20's, but has good punch in the 30's for those transients that we all like. It wont rattle the window with pipe organ stuff.