Improve Cerwin Vega E715

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Hi everyone I use some cv e 715 mainly for home theatre duties because of there 15"woofer air pushing duties,but I'm finding I could need a bit more clarity on the mid range. and perhaps the tweeters .I have removed drivers etc and there is padding on side and back walls with bracing half way up cabinet.Now I realize they are what they are but anyone who can chime in and help this novice with possible improvements to cabinets and replacement drivers of a higher quality that would be appreciated thanks.
 
My CVs
Use a sealed back midrange...so no enclosure needed.
Have the 12" woofers run fullrange without a crossover
Have some carpet padding on 3 walls

I use them as subwoofers and integral stands for my DIY mains ;)

Replacing drivers is a fool's errand. You will have difficulty sourcing midranges and tweeters sensitive enough to match the woofers. Even if you can, you will need to measure the new drivers and redesign the crossover.

Sell them to some kid for ~1/2 what you paid and buy something better?

If you want to use what you have, look into the "econowave".
 
My CVs
Use a sealed back midrange...so no enclosure needed.
Have the 12" woofers run fullrange without a crossover
Have some carpet padding on 3 walls

I use them as subwoofers and integral stands for my DIY mains ;)

Replacing drivers is a fool's errand. You will have difficulty sourcing midranges and tweeters sensitive enough to match the woofers. Even if you can, you will need to measure the new drivers and redesign the crossover.

Sell them to some kid for ~1/2 what you paid and buy something better?

If you want to use what you have, look into the "econowave".

Maybe ( a fool's errand ), but ( since every-time I get to hear the Audax PR170 it makes me smile & therefore ) I figure everyone else ( with an itch ) should get to own a pair ( even in a franken-speaker ) to begin their audio journey to somewhere better .

The venerable EAW FR153 could serve as an upgrade path ( with the components vertically arrayed ).



This mid will offer out-standing high-efficiency mids @ 400hz to 4K ( when put into a small sub-enclosure //> think insulation-packed, approx 6" diameter, card-board sono-tube ).

Of course, there's the problem of the existing crossover / but if a fellow isn't too picky at this juncture ( & is a CV user going to be ?? ) then I'd just wire it up and have a listen ( ie; nothing ventured, nothing gained & all that ).

:)
 
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No problem chucking couple hundred pounds per side at a improvement as eventually won like to build something but got to start somewhere.

The EAW 153 ( plus a few other models ) uses a small round waveguide ( with a compression driver behind it ).

If you look around ( on your side of the Atlantic ) you might find this little guy to retro-fit to your CVs.
This is available in N.A. at FullCompass.com, as part# 504002 .



That guide ( or similar ) driven by something like the Peerless Compression Driver ( crossed around 2.5K ) will offer a very good HT experience ( IMO, after a network gets created & dialed in ).

:)

PS; that Audax PR170MO, is available in the UK from FalconAcoustics.
 
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Thanks guys i guess frankenspeaker it probably will be as I have gone through 6.5" to 10" kefs up to these 15" speakers and even though they are what they are I prefer there air moving abilities for home theatre after wearing out my sub twice before ,with my style music even with a sub .The mid range is in its own sealed space and I have no problem adapting the box for a higher quality mid,trying to find out crossover of existing mid so to not have to alter crossover yet.Will check out to see if I can match up mids with your example.The econwave kit looks great but the 15" Vega drivers are unfortunately a must till I could find a better one of them as well.
 
The econowave could likely use the Vega 15. Worth looking into.

This PRV waveguide ( 152i clone ) is sonically nice & can look good over a 15" woofer ( & through the economics of eBay's "Global Shipping System" ) can now be acquired in most countries at reasonable cost.

Search eBay for the "Parts Express" store / then "PRV" and then you can find out the cost to have a pair sent to the UK.

An externally hosted image should be here but it was not working when we last tested it.


Buy a pair of B&C de250's locally ( & then use a Zilch econowave network designed for this horn/driver combo and live with the "wrong woofer" lash-up ).




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:)
 
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Thanks for the advice appreciated, first up from what I could find the crossover from the cvs woofer is at 500hz with 102db 400watt sensitivity and the midrange at 3000 hz 94db 60 watt. Now what I like about the cvs is there low 20s hz extension presumably because of the 18X18X36" box with two 4" ports which is tamed with a yamaha digital equalizer .I found the audax pr170 which is 100 watt 100db sensitivity ,now as any mod I do will be compared with the other original speaker what difference could I expect like for like ? and also what improvement per se could I expect from say the eminence woofer,is the cv driver really that crap sorry if I sound like a simpleton .I could buy a econowave kit I know but unless I can keep the low 20 s hz extension it's a step back and I have a empty box which can be modified to whatever.
 
Since you like your current woofer, the obvious route is to continue to use it.

Assemble one of the smaller Econowave designs ( like the Delite10 ) and then use your CV only as a sub-woofer.

If you aren't quite up to DIYing ( for HT ) at this time ( that's alright ) go buy something ( from the pro-sound world ) that has a suitably sized ( 8 or 10") woofer with an @ 95db sensitivity.

The plastic boxed Mackie C200 does a very credible job ( in the home HT category ) for easy money.

If you don't like them ( or eventually think you can build better ) they'll actually have some resale value.

Mackie_C200_C200_Passive_10_2_Way_368652.jpg
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That's clearly a Celestion compression driver ( very good quality ).

Read this thread at AVS for a good overview on this speaker.

:)
 

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It's not so much that I like this woofer but it does the job especially when equed,mine do not sound like boom boxes at all.On the sub woofer front I already have a b&w asw 750 to reach lower down so I'd prefer to make what I have better by whatever means so I can directly compare with the old speaker.Going back to the mid range audax driver being 6 db more sensitive then existing driver what will that mean realistically ?
 
It's not so much that I like this woofer but it does the job especially when equed,mine do not sound like boom boxes at all.On the sub woofer front I already have a b&w asw 750 to reach lower down so I'd prefer to make what I have better by whatever means so I can directly compare with the old speaker.Going back to the mid range audax driver being 6 db more sensitive then existing driver what will that mean realistically ?

The PR170 only has a useful ( averaged ) sensitivity of @ 95-96db. ( measured from 400hz to 3000hz ).

See the pic;

An externally hosted image should be here but it was not working when we last tested it.


You're (re)quoting from ( Audaxs own lit ) of that 100db figure is a typical mistake.

FWIW, you'll never find a studio monitor that states its system sensitivity as more than 95db ( if they use one of these mids ).

FYI, even if it actually was 100db / that's what variable Lpads are meant to accomodate ( component balancing ).

:)
 
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Before going any further you should document the existing crossover .

Take pictures of it in place ( if possible ), make notes of which wires connect to what, then completely remove one and draw out it's schematic .

Take pictures and measurements of the existing mids and tweeters ( show front & backs so that people can get an idea of their Q-factor.

Measurements of the existing midrange dog-house are necessary.

:)
 
Finally got around to pulling them apart,bought some audax pro 170 mid range and ordered some audax TWO25A26 tweeters,can someone recommend where they need to crossover and a made up crossover or has anyone got a schematic for certain vega crossover CXS -GN2050 ,also can anyone suggest a alternative 15" woofer for these 6.75 cufoot boxes thanks in anticipation.
 

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IMHO, you need to hook up with a local pro who can provide realist advice for your refurbishment.

From what I can gather there is no mid-range sub-enclosure in your e175's .

If true, that right there would help explain lack of clarity you first mentioned 2 years back ( ie; the mid is being modulated by the internal sound-waves/pressure produced by the woofer ).

You now have some real nice drivers coming (with those Audax ).

Don't squander the opportunity to make something nice sounding by trying to do this without professional help.

You'll need a custom network designed for the drivers you have on hand.

This pic is returned by a Google search for your woofer type ( & I assume its yours ).
It seems to show no midrange sub-enclosure ( which needs to be rectified ).

IMAG0014.jpg


If you intend to use the existing enclosure you will need to find a way to retrofit a separate sub-enclosure into that cabinet.


:)
 
diyAudio Member
Joined 2007
If that is the CV speaker I think it is then I see no problem in keeping the woofer and using a plastic can as the mid range speaker enclosure in the short term.
But I did think that these speakers were better with the port stuffed tightly with foam. If these were a mates speakers that is, so many cheap CV boxes out there with good loud R&R bass and iffy midrange and top.
 
Thanks for the replies guys,first off the mid range did have a small plastic enclosure with stuffing and as the audaxs are bigger i have ordered some 6" cardboard tube from your previous advice,i can't recall where but I read they need a .2 cubic foot enclosure which suggests a 14" tube would this sound about right ? The lack of clarity as well is my bloody tinnitus so any improvement would be great.These speakers do indeed sound better with ports foamed which limit output to above 40Hz and when removed for ht.Previously with the drivers i made up a baffle with a view to copy jamo 909 the sound was more open but because of my room limitations ie small UK room there close to wall,I've read they would not work welcome to wall.Anyway i digress these speakers will be hopefully a learning curve to making some proper ones but this is the first step, with a view to the crossover have you any idiots guide as there is soo much glue on these crossovers i fear i will break them trying to disassemble them and would i be right the crossover would benefit from being higher with these pro 170s.Also on these E715s they have 2 way switching on mid range and tweeter circuits ,should i just bypass them ?.
Anyways any advice greatly appreciated to make these convinced sound like focal utopias .
 
Matyam,

Thanks for the assurance that there's a separate enclosure for the mid-range.

Typical mid-enclosures are .2 to .3 cu ft ( IME with JBL stuff ).

Your Audax components are going to require a new/custom crossover.

I guarantee that the existing one is not applicable.

I think your best approach is to hire someone local ( maybe Falcon ) to design a custom network for your drivers.

Cross-over points ? @ 350hz ( for woofer to midrange ) + @ 3Khz ( midrange to tweeter )


:)
 
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