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10" Woofer ID Help Please

Bratwurst7s

Bratwurst7s

In The Frying Pan
Subscriber
I have these 10" woofers that I bought from Speakerlab back in 2000. What I ordered was a pair of W1038P. What I received were labeled W1058P for $75 each. I've had no joy ID'ing just exactly what they are. Aside from the Speakerlab label they have "1054", "1056", and "9910" printed on the back of the magnets. They have foam surrounds and black polypropylene cones.

Paul at The Loudspeaker Store told me that he thought they might be from Madisound but didn't have anything more specific than that and I haven't been able to find something that matches on theis site. To me they don't look like the W1038R from Madisound, and anyway they have foam surrounds rather than rubber.

Can anyone help me to ID these so that I can find some TS data on them?

Thanks,
James
 

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Likely made by Gefco, which i believe is now defunct.

Best bet is to beg borrow or buy DATS or similar and run the software on them.
 
They are definitely Gefcos. The bad news is, they never had an actual catalog - at least according to someone I know who sourced drivers from Gefco back in the day. You could spec whatever you wanted and Gefco would build it, but the model number doesn't really tell you any more than "W", "M" or "T" for woofer, mid and tweeter, the magnet weight and type.

W1038P would be a 10" woofer with a 38 oz. magnet...not sure what the "P" is - perhaps polypropylene? If you got 1058s instead, it means you got a heaver magnet. "9910" is the date code - made the 10th week of 1999.

Gefco closed up shop about five years ago. They were based in Grayslake, Illinois and supplied drivers to a whole range of US-based speaker makers...until all that moved elsewhere.:tears:

Happy trails,
Larry B.
 
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Thanks guys. That's a start. I'm not sure where to go from here, but thats a start. So it sounds like SL had these 10"ers produced to their spec? Did Gefco make a quality product?

My problem at this point is that I have no experience in using any speaker measuring software, complicated by being a Linux user. I have much to learn. But what the heck. One step at a time. Thanks for your help.

James
 
Before Gefco closed their doors they did manufacture the Madisound brand of drivers.
Gefco made oem drivers for many speaker companies over the years.

I have the spec sheet somewhere for the Madisound drivers and will post them later if they match the driver model numbers you have.

I also have some oem Gefco drivers.
 
sm19422 said:
Before Gefco closed their doors they did manufacture the Madisound brand of drivers.
Gefco made oem drivers for many speaker companies over the years.

I have the spec sheet somewhere for the Madisound drivers and will post them later if they match the driver model numbers you have.

I also have some oem Gefco drivers.
Click to expand...

Ahhh. Then perhaps that's why their name kept coming up when I was googling the Madisound 6102 6-1/2". Thanks, I'd be interested to see that spec sheet if you find it.

James
 
I found the spec sheet for the 1054 driver. All of the other Madisound 10" use a dual voice coil and I think your driver is a single voice coil model.

Fs 24.6hz

Rscc 6ohms

VcL@1K .24mH

Qts. .237

Mmd. 42g

Vas 160 Liters

Xmas 3.5mm, Efficiency 92db, Power 125 w, Magnet 30 oz.

QB3 alignments

Rg .9

Vb 42 liters.

F3 43hz

Fb 35.7 Hz

Port diameter 3" port lngth 7.8"

I would suggest using this alignment since it gives the lowest Fs
 
Bratwurst7s said:
Did Gefco make a quality product?
Click to expand...

They were the original OEM for Polk, back when Polk was making speakers in Baltimore, and Matt Polk was appearing in ads wearing a lab coat. They also produced drivers for quite a few other USA speaker brands.

I think their speakers are excellent, I have several. Vented magnets, butyl rubber surrounds (yours don't have either), quite robust design. Every bit the equal of CTS or Heppner.

Happy trails,
Larry B.
 
You might also be able to get some data from Madisound with a nice inquiry and pics, and data that you have regarding the SL info, or post an inquiry to their discussion board.
 
mech986 said:
You might also be able to get some data from Madisound with a nice inquiry and pics, and data that you have regarding the SL info, or post an inquiry to their discussion board.
Click to expand...

Those are the driver specs in my last post.

I didn't know that Polk had used the budget drivers that were sold by Madisound in their own line of speakers.
 
bowtie427ss, 1tumbleweed, sm19422, mech986, guys, thank you very much. You've all been very helpful. So it at least looks like the woofer is worth keeping. 58oz seems quite hefty for a magnet. Almost more like what Speakerlab was using for their Nestorovic systems.

One last Q. When/if I get the DATS or other testing software am I right in understanding that I'll need to pull the woofer, get a mic and drive the woofer alone on my workbench to run the testing software? I have no experience with that, yet.

I've improved the high and mid areas of my speakers and now the bass is feeling a bit left behind, somewhat muddy and indistinct. Throwing together some rudimentary speaker stands yesterday brought some interesting results. I only gained about 2" in space above the floor and moved the speakers another couple of inches from the back wall and the bass seems a bit clearer. Next will be building something more permanant that gets the cabinets 4" or so off the floor and some foam to place between them and the stand instead of rugs.

I got some help in a different thread finding a room measuring software that will run in Linux, so my next step appears to be buying a mic and learning to sort out what I can do to improve the room.

Budget permitting I will also buy one of those REK RAG-101 Low Frequency Signal Generators listed in the DIY forum, and a small LP-2020A+ Lepai Tripath Class-T Hi-Fi Audio Mini Amplifier or something similar to use for bench testing my drivers. I also have access to a Fluke Scopemeter from work. Then I just have to learn to use all of that.

After that I can address possible crossover improvements like air core coils for the woofers and poly caps and mox resistors.

Am I heading in the right direction? Any other suggestions?

Cheers,
James
 
One last Q. When/if I get the DATS or other testing software am I right in understanding that I'll need to pull the woofer, get a mic and drive the woofer alone on my workbench to run the testing software? I have no experience with that, yet.
Click to expand...
DATS, and the other Smith/Larson Woofer Tester suites are stand alone and just use a simple USB interface(included), that requires a simple calibration.

You will need to pull the driver, and generally support/suspend it a ways from any reflective surfaces. The software comes with pretty comprehensive instructions. A freshly booted PC with no other apps running can help ensure smooth results your first time out. It's always good to verify your setup and procedure by running a driver with known parameters if you have one available.

Measuring Vas will be the most difficult as it's done by either adding a known FIXED mass to the cone, or loading the driver in a test box with a precisely known volume(requires knowing the precise internal displacement of the driver itself).
 
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OK. Looks like I have some things to buy over the next few months. This is going to be fun learning how to do this. My understanding of TS values is in the early stages. I understand some values a bit in a theoretical way, some not at all. And I'm lacking in being able to conceptualize how they work together.

For instance, that Fs needs to be below the working area of a driver makes sense to me (if I'm understanding that correctly), but I don't know how much. That the different Q numbers can show the compliance of a driver makes sense, or that Bl and others can show the strength of the motor, but I don't begin to understand how to use them to choose a driver. But It's going to be fun to learn.

First off, with an Fs 24.4 compared to 16.7 of the Speakerlab W1008R (closest I can find to my original W1008P) the W1058 would seem to have too high of a resonance. And an Xmax of only 3.5mm seems quite low, I believe that the W1008R had considerable more movement. But I can't confirm that with any published specs.

Well, enough thinking for today, I believe it's time to listen to some music. Thanks again.

Cheers,
James
 
OK, after a long pause, another question.

What would be the effect of using a replacement driver with a Qts of .34 (or .28) instead of the oem driver with .412 in a closed box (of 97 liters with a 12"woofer in parallel)?

Or using a driver with similar to original Qts but with a higher Fs (29-31 instead of 17)?

I'm faced with the fact that it's proving impossable to find a woofer with the same specs as the oem woofer, and I will have to make a compromise somewhere, either with Qts, Fs, or SPL. But I'm completely out of my depth in trying to understand where the lesser of any evils would be.

Thanks,
James
 
Reading kcbluesman's thread "Don't leave us hanging" made me realize that I did exactly that. So to those of you who helped me here I settled on buying a pair of ScanSpeak 25W-8565 woofers. They are a great improvement on what I had and I'm very happy with them. Thanks for all of your help.

Cheers,
James
 
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