how do you measure the coil in the crossover?

Thanks for your responses, I should also mention that the speakers are bi-wired as well, so there are two coils or chokes per crossover. I take it that these cannot be measured for value with an ohm meter?

I don't know where you planned on buying the parts from, but you can always send the coils into Madisound, they can measure them and then sell you the "most correct" Goertz coil for your specific application.

Personally, i would tend to agree with Karls. This is, i would worry about the capacitors and internal wiring first and then take a look at the coils. If the speakers really are THAT "cheap", it might not be worth the investment that you are talking about making. Four inductors, decent capacitors, wiring, etc... will set you back over $100. If you've got an unbraced box that resonates and leaks like mad, has nothing to minimize diffraction and makes use of drivers that are low grade, putting that much money into the crossovers isn't going to help that much. In a case like that, you'd be FAR better of starting from scratch and building your own speakers. Sean
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I should have mentioned that the speakers are the RTS-9 floorstanders from Sound Dynamics, and the cabnets are really built, and braced quite well. What wire would you use to upgrade?

A lot of people like to do what your planning on doing but it is not as simple as one is lead to believe. The crossover in a given speaker is designed to operate correctly with the given components in the crossover. When you change components, the crossover is being changed as for frequecy of the crossover point, impedence and the like. I have spoken with numerous speaker manufactures on this and they have ALL said without fail that you have changed the design and the speaker will not measure the same. The drivers and crossover are matched to operate together as they are. Without proper test equipment, you are tuning in the dark. Yes, the speaker could sound better to you but is it still accurate? You tune to an unknown parameter. It could sound worse. Of course, if you don't care about accurate, tune away!

My experience is that changing / upgrading speaker components almost always improves transparency and dynamics as compared to mass produced items. While Bigtee does bring up some very valid points, the key here is to use parts that are identical in specific electrical characteristics to those supplied by the manufacturer. Some variables are bound to change, but they typically change for the better. That is, IF you've done your homework and selected good quality parts to replace those that were factory installed.

Lowering series resistance, reducing thermal and dielectric losses, reducing saturation / increasing headroom, etc... are all good things. The key here is NOT to change the crossover points or rate of slope. Driver blending should have already been taken care of at the factory and you haven't changed that since the electrical characteristics of the "filter" have been preserved. As such, the critical areas of crossover performance should remain consistent. You haven't really changed the glass, you've only cleaned it so that more light can come through.

As to what wire to use, that is a matter of personal preference. Personally, i normally like solid core copper with the lowest amount of dielectric absorption possible. This means air, teflon, enamel or cloth insulation. It is not as flexible or easy to work with, but once you put the speaker back together, it probably won't be coming apart anyhow. While i do use stranded wire in some places within my various systems, i typically resort to this when the wires themselves will be moved or are in a traffic pattern. Solid wire IS a better conductor but it is also more brittle.

If in doubt, use whatever wire that you're already using to feed the speakers from the amp with. Just make sure that ALL of your connections are properly prepped and secure prior to soldering. A rugged mechanical connection is prefered over relying on the solder to hold things together by itself. Try not to think of solder as "glue", but rather as a sealant to what was already a good electrical connection. Sean
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