I bought a pair of Cerwin Vega XLS-215 s with a little bit of shipping damage to the cabinets for a great price.. Stock they sound a lot better than I expected. It seems that the newer CVs sound way more balanced and refined than their old stuff and still go like @#$%!!! I think that they were well designed and are limited by CV building them to a low price point and making them bullet proof for their target market. I think that beefing up the cabinets with some internal braces, and a thicker front panel and adding some XL audio spikes will make a difference.but I think the biggest improvement will come from upgrading the original wiring and crossovers using higher quality parts and also eliminating all the speaker protection stuff. CV was nice enough to send me a schematic of the factory crossover which I will attach to this post. I will be am willing to spend as much as $300 for better parts if absolutely necessary but don't want to spend more than I have to and use the surplus for some other project or more music. They will be used for primarily for playing music in a 2 channel stereo set up. I've built/upgraded quite a few speakers over the years and am pretty good at cabinet construction but have never been very good with crossovers.I would really appreciate any input and advice you can give to help me get the most "bang-for-my-buck" on this project. Much Thanks in Advance!
Crossover upgrade I Need advice
- Thread starter 20over
- Start date
Register to hide this ad
pete_mac
Super Member
The original crossovers aren't absolutely terrible... they do use polypropylene or polyester caps for all capacitors in the tweeter and midrange circuit, with only the shunt capacitor in the woofer circuit being electrolytic.
What you could theoretically look at doing is:
Realistically, there won't be a much to be gained from upgrading the poly caps. We're talking tiny, incremental improvements. I do like the Clarity Cap ESA caps as reasonably priced upgrades in my experience.
Regarding the inductors, you will need to check the DCR of the inductors and match them with whatever aftermarket items you fit. This could result in some fairly cumbersome, difficult-to-mount inductors. If you don't match the DCR closely, you will alter the crossover electrically and alter the response of the speaker adversely (unless you have a UMIK-1 or similar to undertake before and after measurements of your drivers and speakers, and can make on-the-fly changes to the crossovers).
Regarding internal wiring... choose your poison and go wild! Again, there are minimal gains to be had IMHO, but the DIY aspect is fun.
Cabinet bracing is a definite area to look into. Some hardwood 1" dowels mounted between opposing sides of the cabinets and glued/epoxied into place can work wonders, without significantly affecting the internal volume of the cabinet.
If the drivers have stamped metal baskets (rather than cast aluminium), I have had good results with fitting narrow strips of Dynamat to the stamped metal basket to eliminate ringing.
What you could theoretically look at doing is:
- Replace the iron-core inductors with air-core inductors
- Replace the cement wirewound resistors with Mills wirewound resistors
- Replace the polyprop and polyester caps with boutique polyprop caps
Realistically, there won't be a much to be gained from upgrading the poly caps. We're talking tiny, incremental improvements. I do like the Clarity Cap ESA caps as reasonably priced upgrades in my experience.
Regarding the inductors, you will need to check the DCR of the inductors and match them with whatever aftermarket items you fit. This could result in some fairly cumbersome, difficult-to-mount inductors. If you don't match the DCR closely, you will alter the crossover electrically and alter the response of the speaker adversely (unless you have a UMIK-1 or similar to undertake before and after measurements of your drivers and speakers, and can make on-the-fly changes to the crossovers).
Regarding internal wiring... choose your poison and go wild! Again, there are minimal gains to be had IMHO, but the DIY aspect is fun.
Cabinet bracing is a definite area to look into. Some hardwood 1" dowels mounted between opposing sides of the cabinets and glued/epoxied into place can work wonders, without significantly affecting the internal volume of the cabinet.
If the drivers have stamped metal baskets (rather than cast aluminium), I have had good results with fitting narrow strips of Dynamat to the stamped metal basket to eliminate ringing.
Drsnaut
Member
If you're changing to air-core inductors I can recommend Jantzens. They're fairly cheap and really greatly build (and baked..).
I agree with changing the resistors. I would recommend for the tweeter section a Mundorf Mres Supreme (in the schematic thats R3). They get pretty darn close to no resistor at all. I like to put a 100k takman carbon resistor on top of that (parallel), a trick I learned from the guy behind humble homemade hifi. * correction, I just see that R3 and R6 are varistors? I would remove these completely. They're there for safety reasons, but won't do the sound any good. R5 a mills would be fine.
The 5uf cap on the tweeter section can make a big impact on sound, here I disagree with Pete that there isn't much to gain here; there is a lot to gain; I would say that would be the biggest gain factor in your crossover. You do need to go as far as changing them to the likes of Audyn cap plus, mundorf supreme, jantzen z-superior, obbligato, etc. Changing a film cap for a film cap only makes a difference once you really step up in build quality. I see Audyn cap plus as the best bang for the buck cap (with higher values it's the obbligato.. a kind of sweeter / acoustic mundorf supreme sound wise... or the mundorf EVO/OIL), when I modify speakers from friends I put these in; they will play with a transistor amp and all will be good and noticable.. without going too far on stretching the budget.
If you don't fool around with the speakers or have house parties with these speakers, you can remove the fuse and the variable resistors (R3 and R6)... Change C1 to a Audyn cap Plus (with a 0,01uf bypass), change r5 with a mills 12w, change L1, L2 and L3 with air-core (I prefer Jantzen over Mundorf and Intertechnik), leave C4 as it is.
The thing you can contemplate over is C3; I would recommend to leave it first and see how you like the changes in the speaker by upgrading the speakers. If you want to put the envelope further you can change it to either Evo Aluminum/Oil or obbligato because they have the same price. The EVO/oil are smaller in size, so if you're in a tight spot, they're perfect!
Nice internal wiring is canare 4s8, jantzen has nice solid-core speaker wiring too..
Good luck!
I agree with changing the resistors. I would recommend for the tweeter section a Mundorf Mres Supreme (in the schematic thats R3). They get pretty darn close to no resistor at all. I like to put a 100k takman carbon resistor on top of that (parallel), a trick I learned from the guy behind humble homemade hifi. * correction, I just see that R3 and R6 are varistors? I would remove these completely. They're there for safety reasons, but won't do the sound any good. R5 a mills would be fine.
The 5uf cap on the tweeter section can make a big impact on sound, here I disagree with Pete that there isn't much to gain here; there is a lot to gain; I would say that would be the biggest gain factor in your crossover. You do need to go as far as changing them to the likes of Audyn cap plus, mundorf supreme, jantzen z-superior, obbligato, etc. Changing a film cap for a film cap only makes a difference once you really step up in build quality. I see Audyn cap plus as the best bang for the buck cap (with higher values it's the obbligato.. a kind of sweeter / acoustic mundorf supreme sound wise... or the mundorf EVO/OIL), when I modify speakers from friends I put these in; they will play with a transistor amp and all will be good and noticable.. without going too far on stretching the budget.
If you don't fool around with the speakers or have house parties with these speakers, you can remove the fuse and the variable resistors (R3 and R6)... Change C1 to a Audyn cap Plus (with a 0,01uf bypass), change r5 with a mills 12w, change L1, L2 and L3 with air-core (I prefer Jantzen over Mundorf and Intertechnik), leave C4 as it is.
The thing you can contemplate over is C3; I would recommend to leave it first and see how you like the changes in the speaker by upgrading the speakers. If you want to put the envelope further you can change it to either Evo Aluminum/Oil or obbligato because they have the same price. The EVO/oil are smaller in size, so if you're in a tight spot, they're perfect!
Nice internal wiring is canare 4s8, jantzen has nice solid-core speaker wiring too..
Good luck!
KKnight
Active Member
After rebuilding two different sets of XO's this past winter and mulling thru this post a few times, I decided to reply-
pretty much agree with what has been said. I add this:
Your best bang-for-the-buck is undoubtedly Jantzen Superior Z for poly's. You can go more expensive but you do not need to. I'll add the following link for reference: http://www.humblehomemadehifi.com/Cap.html. I'd stay away from Clarity, Audyn, and Mundorf for your Vega's.
Over the past few years have had problems with Mills resistors. Always waaay out of spec and got tired of dealing with Mill's directly and their third party suppliers. IMHO there really isnt much difference between sand/cement generics and Mills. Go 5 or 10% and ENSURE they are within that after receiving them.
There has always been a huge controversy about replacing inductors from factory stock. Not that air core isn't superior, but if you replace ANY XO inductor from factory stock and the design, it opens up a whole can of worms. Throws the design way off and the rule-of-thumb is never replace them (even IF they are iron core). I wouldn't replace them. You can research more from speaker pro experts in other forums like PE's Tech Talk.
Sounds like you're in the parts replacement mindset and I'd stick to that. Re engineering your enclosures also can open up a can or worms and unless you're already a established woodworker, etc, any changes you make such as bracing or stuffing can change your internal cubic volume and more. Your XO's are designed for exactly what your Vega's are now.
Again, the aforementioned forum is populated from guys who do nothing but speakers 365. May be a better resource.
pretty much agree with what has been said. I add this:
Your best bang-for-the-buck is undoubtedly Jantzen Superior Z for poly's. You can go more expensive but you do not need to. I'll add the following link for reference: http://www.humblehomemadehifi.com/Cap.html. I'd stay away from Clarity, Audyn, and Mundorf for your Vega's.
Over the past few years have had problems with Mills resistors. Always waaay out of spec and got tired of dealing with Mill's directly and their third party suppliers. IMHO there really isnt much difference between sand/cement generics and Mills. Go 5 or 10% and ENSURE they are within that after receiving them.
There has always been a huge controversy about replacing inductors from factory stock. Not that air core isn't superior, but if you replace ANY XO inductor from factory stock and the design, it opens up a whole can of worms. Throws the design way off and the rule-of-thumb is never replace them (even IF they are iron core). I wouldn't replace them. You can research more from speaker pro experts in other forums like PE's Tech Talk.
Sounds like you're in the parts replacement mindset and I'd stick to that. Re engineering your enclosures also can open up a can or worms and unless you're already a established woodworker, etc, any changes you make such as bracing or stuffing can change your internal cubic volume and more. Your XO's are designed for exactly what your Vega's are now.
Again, the aforementioned forum is populated from guys who do nothing but speakers 365. May be a better resource.
THANKS! I've posted the same question on 5-6 other sites. You are the only ones to take the time to post intelligent, thoughtful helpful responses! I was really baffled by those varistors. I knew they could't be helping the sound in any way but thought they had a dual purpose (resistor or???) that I'd have to compensate for. As for adding bracing, I was only going to add a few 1" hardwood dowels from side to side, front to back and top to bottom. I did not think that small a loss of volume would matter. I was also thinking of adding a piece of MDF or plywood to the front outside face where the woofers are mounted. AGAIN, THANK YOU!!!