DIY help to upgrade my CV E-710's

bravewink

Member
2007-12-30 1:16 am
I'm in need of a new set of speakers for my basement which will be a combination of a recording studio/bar/man room type environment. In my upstairs system, I have a pair of Quad 22L speakers that I really enjoy, but am not allowed to take them from the wife's decor.

Instead buying new speakers, I thought about using the cabinets from a set of Cerwin Vega E-710's for a DIY project. The midrange is excessively recessed and muddy(I know, what do I expect from CV?). I need help with a DIY that will give "audiophile sound".

I think I may be able to use the 10" woofers and the tweeters, but need a 5 1/4 midrange and crossover design. However, I've become used to the soft dome tweeter of the Quads, so I may need to upgrade the tweeter as well.

From playing with home theater setups, I think that when I crossover above 80hz with a sub, the sound is less than ideal. Would using the 10" CV as a "built in passive sub" work with a low crossover point such as 80hz?

Any and all comments and suggestions are welcome.

Sorry, the CV site seems to be having issues with the Discontinued models, but here is a page with a few specs:

http://reviews.cnet.com/separate-speakers/cerwin-vega-e-710/4505-7869_7-6899367.html?tag=sub
 
I don't know this speaker so I can't say form experience, but you may be able to just modify the corssover to bing some life into the mid range. Whilst they wern't expesive speakers they weren't hoplessly cheap either so the drive units should be ok.

If you reverse engineer the crossover you will probably be able to get lots of ideas of what to try from people here. Might be worth a go before you junk the midrange altogether.

Changing the midrange will require measurement equipment to have any chance of making a good crossover. Unless someone has done this mod before and already done the measurements you can't just put three drivers in a box with a generic crossover and hope they will work well. What you get will be a complete lottery.

Regards,
Andy
 

Ron E

Member
2002-06-27 10:41 pm
USA, MN
It is difficult to find DIY drivers that can match the sensitivity of the C-V.
You could simply try an equalizer...;)

C-V often uses cheesy sealed back midranges, you could drill a bunch of holes in the basket and make a subchamber for the midrange, but doing this you are more likely to ruin the driver by getting shavings near the magnet than you are to improve things. ;)

The crossovers in C-V's are also really cheesy. The little ferrite inductors have cores about as thick as a medium sized screwdriver shaft. These are probably saturating and causing lots of distortion at any more than a few watts of input. You could reverse engineer the XO and try to improve it with better components.

I also suggest trying out Speaker Workshop. Measure the speaker's frequency response and see if you can target areas for improvement. It could be that the midrange speaker is not really the problem.
 

bravewink

Member
2007-12-30 1:16 am
Ron E said:
C-V often uses cheesy sealed back midranges, you could drill a bunch of holes in the basket and make a subchamber for the midrange, but doing this you are more likely to ruin the driver by getting shavings near the magnet than you are to improve things. ;)


Well, per your advice, I took a gander inside the speaker behind the midrange. The midrange had a small sealed plastic "bucket" about 5 inches deep (not sure if you could consider it a sub-chamber since it was sealed?)behind the driver. I simply unhooked the wires, removed the filled chamber, attached the wires directly to the driver, installed and WOW what a difference. I still have the other speaker to mod, but even on one channel it dramatically reduced the boxiness and cleaned up the vocals. I only did one so I could honestly A/B non-scientifically test the mod.

I'll see about reverse engineering the crossovers. I have to look up the resistor color codes since it's been awhile since I messed with electronics. It might be somewhat challenging considering the switchable L-pads for both bass and treble frequencies, but fun nonetheless.

Thanks for the suggestions. The first round of modifications were a success.