Monitor 10 Crossover questions

dpage

I could use some help with my Frankenstein Monitor 10 crossovers! (partially of my own doing). I picked up a pair of 10A's a while back. I realized they had the SL3000 upgrade already. At least partially anyways. They had the correct resistors and caps but still had the fuse installed instead of the polyswitch like the SL3000 schematic shows. They also had SL2500 tweeters. I don't think the inductor was changed either. I swapped out the tweeters for RDO-198's and upgraded the crossovers with Clarity Caps. Thanks to those that helped with that. I just now realized that I used a Clarity cap for the low end and a Clarity and a Dayton for the highs. I obviously meant to use both Clarity caps for the highs and the Dayton for the lows.

So I'm wondering if I should replace the Dayton cap with a Clarity or if it's not a big deal mixing the two brands for the highs. Also is it ok to leave the fuse as is. BTW the speakers sound excellent. I prefer them to my B&W CDM 2's, DCM TF-350's, and PSB Image B6's. Just wondering if I'm leaving something on the table the way they are now. I appreciate any advice from those in the know!

westmassguy

You don't mention what type of Clarity caps you're using. Best practice is to use the same make and model cap in the Hi-Pass and Lo-Pass. A lesser grade can be used in the Lo-Pass, but it should, if possible, be from the same manufacturer. For the SL3000/TL mod to work in the 10As, the resistor in series with the tweeter should be 3.0-3.2 ohms, and the 22 gauge 0.4mh inductor in the shunt should be unwound to 0.27mh

dpage

Thank you. I will make those changes. Looking forward to hearing the changes.

westmassguy

You're welcome. Let me know how you make out

dpage

westmassguy - I had a local audio store do the crossover upgrades for me. Just got them back last night. They sound very good in the little bit of listening I did late last night.

One question though. He replaced the .4mh inductor with a .27mh per the SL3000 upgrade schematic but he used an inductor with a much lower gauge. Very thick wire, looks to be 18-20 gauge. As you know the stock inductor is very thin wire. Will this have any affect on sound? I would have to think it would affect crossover points somehow. The resistance would be different correct? Thanks again,

westmassguy

Yes it will. The schematic clearly shows .27mh @ .5 ohms. The resistor in series with the inductor must be increased from 2.7 to 3.0 ohms to compensate. The total DCR of the original shunt should have been measured first. The original inductor could have been unwound, and would have been about .5 ohms.

dpage

I was afraid of that. So just to clarify you're saying I need to change the resistor from 2.7 to 3.0 ohms? Just out of curiosity can you tell what effect on sound or crossover point what he did will have?

westmassguy

dpage wrote: »

I was afraid of that. So just to clarify you're saying I need to change the resistor from 2.7 to 3.0 ohms? Just out of curiosity can you tell what effect on sound or crossover point what he did will have?

When I use a 20 gauge Inductor, yes, but you should pull the crossover and measure the DCR directly. The crossover point, slope, and spl of the tweeter may all be affected. Those values shown on the schematic were chosen for a reason.