[Eric F]

Hi, new here. Hope I am in the right place. I am retrofitting a 3-way crossover.  All new caps, inductors, resistors. The hi and mid have PTCs in front of the circuit. I understand their purpose but wonder of their necessity.  Generally I see them on factory crossovers but never on DIY upgrades. I have never tripped mine that I could tell. They are very big powerful speakers and I would assume it would take an awful lot to set one off. My tweeter and mid are not high dollar and I was considering omitting them. There is a fuse protecting the bass also. Any thoughts would be appreciated. I am an electrician and am sketchy on eliminating protection but I don't drive them even close to full power.

[Eric F]

They are. Can't figure out how to edit. Lol.

[richidoo]

Welcome to AudioCircle, Eric!

They are unnecessary, you may safely remove.

Your ears and brain combine to provide adequate protection from driver damage. If it sounds bad, turn it down.

The sound quality will be noticeably improved without them.

[FullRangeMan]

What speakers are these?

[Eric F]

Nothing fancy. A set of Cerwin Vega SL 15s. We like to jam out sometimes and these fit the bill, we still never push them very loud. They are in the living room for the surround system. I just thought it it would be a cool project to replace the very unimpressive crossover with some better parts.



The second image is new crossover. I want to see if we can get a little better/cleaner sound. They aren't as bad as they could be, but could be way better.

[Eric F]

Sorry first is new second is old. All very thin wound iron inductors and 100v electrolytic caps. I went to 16 ga air cores on the mids and highs. 14ga laminated core on the base, and nice film caps.

[FullRangeMan]

Eric the original xover is compatible with the quality of the speakers and with the manufacturer's intended use IMO, don't spend too much.

[Eric F]

Ya, I get it. It's not about the money. I can afford it. We have a long crappy winter so its more of a hobby project/experiment to see if all the claims are true. If it improves them great, if not I  will know they have good components and they have reached their full potential. I believe with speakers like Cerwin Vega or similar, many have a good design for their purpose but always cheep out on the parts. Tradionally very good drivers, but junk boxes and cheap crossovers. Old school Simi Valley built and new Gibson Chinese built are very similar in build quality from the ones I have seen. The "mdf" is a  finer grain and more dense in the new ones. My goal is to make them how they should have been built. Thanks.

[Eric F]

Also, I will keep the original 100% intact for obvious reasons, also if someone ever wants to buy them I will have all original parts if they prefer.

[richidoo]

When upgrading stock inductors it's good to keep the DCR of the new coils as close as possible to the original to maintain the original filter function. You can measure the old DCR with ohmmeter.

If you replace iron core coil with air core coil, it requires much longer inductor winding to achieve the same inductance, so the DCR will be higher if the wire gage is the same. If you increase the wiregage you can lower the resistance to be similar to the original, or close. You are using larger gage windings so you're on the right track.

[FullRangeMan]

Also, I will keep the original 100% intact for obvious reasons, also if someone ever wants to buy them I will have all original parts if they prefer.
Nice, seems a useful spare devices

[Eric F]

I am an electrician so I have a good grasp on the theory, though most of this stuff is at a much smaller scale than I am used to working on and this is my first attempt at anything like this. I have built speakers, but used factory crossovers. I also did a lot of research and what you posted seems to be the consensus. I matched all values with 3% caps, de-rated tthe coils hoping to keep it right where it should be. Testing them on my shop speakers they work properly. I will try them for real this weekend.

[Letitroll98]

I think this is a great winter project.  I've wondered if simply increasing parts quality in an already okay speaker design would increase the sound quality.  We already know from Danny Richie that redesigning a crossover can improve a mass market speaker, but what about simply upgrading the crossover parts.  My Meadowlarks were hot rodded by the manufacturer with better crossover parts and internal wiring, can't remember if he upgraded the drivers, but I don't have any originals to compare anyway.  Pat charged an extra $400 for them so it must have done something.  Please keep us informed about the progress.

[Eric F]

Many people believe better crossover parts with tighter tolerances can improve sound clarity, improve driver control, many claims. Much of it makes sense, much of it I think is only detected with testing equipment, some of it is pure snake oil I am sure. In theory it should improve performance, hopefully  it doesn't degrade performance. If it does I will attempt to fine tune it, if that fails I will just hook up old crossover and use parts for my future speaker build. I like the speakers, but would like the mids and highs to open up a bit. The caps I chose specifically because of how each supposedly performs. Janzen Z caps are supposedly nice with silk dome tweeters, Clarity CSAs are supposed to be good for midrange. I probably went overboard and probably wouldn't know the difference between film caps. After reading up I decided to not go crazy but go with somewhat higher grade caps because in my mind, if I am going to hear a difference I need the best components I can get (within the budget). I really want to see for myself, there is a lot of opinions out there.