Electrolytic vs poly

I am happy to report that I have just completed a recap of a set of Technics sb 6000a. There were 8 caps 3 of which were 68uf a 33uf a 22uf a 15uf and a couple smaller. The highest values are in the high pass circuit. Now the speakers are not worth that much money so using poly’s with those high values was not something I wanted to do. The speakers sounded like they had a wet blanket over them and I thought how much better can they get. What if I spent $200 on caps and they still sound the same. I’d be disappointed as these were inherited by me from my late Uncle who purchase them new. I decide to go the all electrolytic route with mundorf e- caps. I’m very happy to say they turned out fantastic. Nice Punchy Bass, clear mids and nice highs. So if anyone else is in fear of using electrolytics instead of Polly’s, don’t be I will definitely do it again when needed.,

I should also mention that the Caps all electrolytic, that I took out were quite close to spec with only a couple being 20% out. As I measuring these old caps I’m thinking now this is really going to be a waste of time. So I was even more surprised with the new caps.

When replacing vintage caps, you need to measure the ESR, ESPECIALLY in parts that go to ground, or the even numbered poles.

Usually the big problem is in low pass filters. Replacing an old electrolytic with a modern cap may lead to unexpected drops in impedance. Measure the ESR and compensate for any differences with additional R values.

I've heard from several experimenters who felt that doing this in the bass was in fact quite beneficial.  Axon is a cheap version of Solen which in this case works quite well and is inexpensive.

It does. Thanks. I have used Monacore MKP from Wilmslow audio several times. I like their sound in British speakers and there price. 

If you have to go with electrolytics then don't forget to order bipolar ones... I'd go with cheap pp over electrolytic every time. It's fine to mix capacitor types and values. Each cap either in parallel or on its own needs to be higher than the highest rms voltage... those speakers are 100W into 6Ω which is around 25Vrms, double it for safety - all caps should be rated 50VAC or higher but they don't need to be the same as one another.
Hope that helps.

Thanks. The reason for my post is recently I have undertaken a recap on a couple of sets of Technics sb 6000 and 7000 and they both have multiple 68uf caps in the high and midrange circuits. Cost wise it doesn't make sense to use anything other than Electrolytic's.
The only E's I have found are the Mundorf E cap and Alcap's.

Should you always use the same type of cap in a circuit? Example.. If there is a high value and a low value cap in the high circuit should you use either electrolytic or poly or can you or would you combine E's and p's? They would also be much different voltages. 

For inexpensive caps, I really like the Mundorf MKP line. Dark and smooth. Works great as replacements for the Solen OEM caps in most Focal speakers. Takes about 4 days of regular listening to finish breaking in.

My advice is, if you can, spend $30 (total) on a project and make up your own mind. :)

As for the high end Mundorfs, I find them far too colorful for my own tastes and prefer Clarity.

Electrolytic capacitors (regardless of the manufacturer) produce much more distortion than polypropylene, for that reason I never use them to set a time constant (like in a crossover). They are pretty much irreplaceable in power supplies because as you say they are available in much higher values. It is also possible to use them to AC couple the signal, as long as they are grossly overrated they will not affect the signal within the audible frequency range.

There is nothing wrong with using multiple capacitors in parallel (you just add up the values), unfortunately this doesn't apply to the voltage rating so each one of the capacitors needs to be rated in excess (usually double) the maximum output voltage (RMS). The other advantage is that you can measure each capacitor's value individually and come up with a combination that get's close matching for left and right channels. All you need for that is a pretty basic multimeter.

I'd advise taking a look at something like the Wima MKP 4F before shelling out on the boutique types.