Xover upgrade advice for a newbie

[nwsalmon]

Hello all,
I have an existing xover cap that is a 3.5 uF on my Infinity Col. II's. PE didn't have a 3.5 uF but they did have a 2.0 uF and a 1.5 uF. (Dayton Precision 1% Metallized Polypropylene Capacitors)

I'm a newbie at this so I'm assuming I can just solder the two new caps together in parallel for a total capacitance of 3.5 uF?

So, looking at the attached cap picture I've included here's what I'm assuming I need to do:

* twist the ends together as shown in the picture
* solder each lead of the new caps where the existing cap was attached


Anyway, let this newbie know if I'm on the right track here before I start soldering.

Thanks in advance for any help or suggestions!

 

[TLS Guy]

Hello all,
I have an existing xover cap that is a 3.5 uF on my Infinity Col. II's. PE didn't have a 3.5 uF but they did have a 2.0 uF and a 1.5 uF. (Dayton Precision 1% Metallized Polypropylene Capacitors)

I'm a newbie at this so I'm assuming I can just solder the two new caps together in parallel for a total capacitance of 3.5 uF?

So, looking at the attached cap picture I've included here's what I'm assuming I need to do:

* twist the ends together as shown in the picture
* solder each lead of the new caps where the existing cap was attached


Anyway, let this newbie know if I'm on the right track here before I start soldering.

Thanks in advance for any help or suggestions!

That's what you need to do. What's wrong with the cap in the infinity? Unless the original cap you are replacing is a non polarizing electrolytic type, what do you expect to achieve? I have the feeling you may have sniffed some vapors wafting from the loony high end.

 

[nwsalmon]

That's what you need to do. What's wrong with the cap in the infinity? Unless the original cap you are replacing is a non polarizing electrolytic type, what do you expect to achieve?

There are two caps on the xover (so four total for both xover's) and one cap looks like it is cooked. So I figured while I was at it I might as well replace them all. One cap is a foil type and the other is a electrolytic.

About $25 for the caps and $40 for the speakers at a local thrift shop and I'm still ahead of the game.

Thanks for the advice.

 

[TLS Guy]

There are two caps on the xover (so four total for both xover's) and one cap looks like it is cooked. So I figured while I was at it I might as well replace them all. One cap is a foil type and the other is a electrolytic.

About $25 for the caps and $40 for the speakers at a local thrift shop and I'm still ahead of the game.

Thanks for the advice.

Your description would make those 12 db per octave second order crossovers.

Which cap is cooked? A cap in a high or low pass filter? If there was enough voltage to cook a cap, then there is likely a fried voice coil in a driver. You should definitely replace any electrolytic caps, they have no place in passive crossovers.

 

[nwsalmon]

Your description would make those 12 db per octave second order crossovers.

Which cap is cooked? A cap in a high or low pass filter? If there was enough voltage to cook a cap, then there is likely a fried voice coil in a driver. You should definitely replace any electrolytic caps, they have no place in passive crossovers.

I've been collecting specs on the Column II and my list reflects 6 db per octave. There is also a pair on eBay right now and the description shows them being 6 db per octave.

Column II eBay http://cgi.ebay.com/Infinity-Column-II-Vintage-Hi-Fidelity-Loud-Speakers-2_W0QQitemZ380039383792QQihZ025QQcategoryZ50597QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Well, I guess I'll need to examine the voice coils for damage. I'm too much of a novice to know what a high/low pass filter is. I'm still learning.

BTW, your pics remind me of my cousins audio/video system. His equipment though is all rack mounted in a special room. I don't even know what most of it is but it is really impressive. He has eight theater seats set up with a projector system in the viewing room that is just fantastic.

Also, I couldn't help but notice that you're using Carter gear and that just happens to be my name.

Thanks again for your reply! I'm learning as I go here and loving every minute of it.

 

[TLS Guy]

I've been collecting specs on the Column II and my list reflects 6 db per octave. There is also a pair on eBay right now and the description shows them being 6 db per octave.

Column II eBay http://cgi.ebay.com/Infinity-Column-II-Vintage-Hi-Fidelity-Loud-Speakers-2_W0QQitemZ380039383792QQihZ025QQcategoryZ50597QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Well, I guess I'll need to examine the voice coils for damage. I'm too much of a novice to know what a high/low pass filter is. I'm still learning.

BTW, your pics remind me of my cousins audio/video system. His equipment though is all rack mounted in a special room. I don't even know what most of it is but it is really impressive. He has eight theater seats set up with a projector system in the viewing room that is just fantastic.

Also, I couldn't help but notice that you're using Carter gear and that just happens to be my name.

Thanks again for your reply! I'm learning as I go here and loving every minute of it.

I didn't realize they were old three ways! Your description of two caps per crossover would make the first order 6db filters. You can't expect much from those. The woofer will be driven up to 6 KHz, the 24 db point with those filters. The 18 db point will be 3 KHz The mid will operating from 94 Hz to above 20 kHZ the 18db point is 40 KHz. On the tweeter the 12db point will be 1250Hz. Those speakers are pre ferrofluid in the gap, and I bet the resonant frequency is around 2 KHz. So the tweeter will be driven well into its resonant range.

In those days the mid range speakers were cheap TV speakers or similar.

Those speakers will not perform even close to modest modern ones.
Any way best of luck with them, but don't expect too much from them. By the way, since the tweeters have no ferrofluid, which also cools the voice coil and the filter is first order, the tweeters will be very easily fried by modern amps with digital sources. You have to remember the highs on LPs were always rolled off to a variable extent, and I think that is the main reason many people seem to prefer LPs. The advent of digital sources in the early eighties caused a huge change in speaker design. Also together with the understanding of Thiel and Small's landmark paper around 1974, and the advent of computer modeling and testing, speakers made quantum leaps in performance.