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CF-4 crossover rebuild, upgrades, et cetera


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A panel brace should be 1x3 (on edge) so if you want to use say 3/4" ply for your braces make them 3/4" x 2 5/8" your strapping to tie all the braced panels together so the cabinet cannot flex should be 1x2 which is actually 3/4" x 1 1/2" you can use just about anything for this scrap ply or fir strapping just glue in place.

 

 

What Moray is talking about is what I did NOT do.  He is suggesting making a spine (or brace) with the 1" of the 1x3 on edge.  He is then suggesting the spine run along the entire bottom/center, staying on-center all around the back, and finish along the top panel.  I'm thinking you might also want a spine running from the sides UP to the front baffle.  Have I got that correct Moray? 

 

Something that might look something like this:

 

seos_2cuft_talla_3.jpg

 

 

If you follow Moray's bracing suggestion, I would suggest removing all the stock bracing so you have room to work.  Then do your spine work, then the side bracing.  I didn't want to do that much work, and I wasn't confident I had the woodworking skills to put the baffle support braces back exactly where they needed to be to level the baffle. 

 

I tied a couple of braces from front to back, then a long brace from top to bottom.  I then screwed the pieces together so five sides are solidly connected through the center.  I did not brace from back wall to front baffle.  I see this center-bracing style more commonly in DIY subs, and it was the type of bracing the stock CF-4 uses.

 

d4b14cef_vbattach198452.png

 

So I took the coward's way out.  :lol:  (which admittedly, did not work for sonic improvement, at least according to my ears)

Edited by wvu80
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Mr. djk, thanks for the link to the spec sheets.  I already had the DH1506 PDF file.  I have seen several DH2's on the used market, but I had never considered it.

 

I bought a pair of DH1's at one time for my CF-4 project, but the throat used a 4-bolt pattern and I thought it was beyond me to make it fit.  Is the DH2 the same basic CD with a screw-on throat?  That sure would have fit my application better.

 

Other than the spec sheets, what are you saying about the two models?  The DH2 sure looks like a nice robust driver.

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Very refreshing to see all this talk on the cf4's. They are amazing speakers and some really don't know there greatness or potential.

 

Crites only changed the caps in the crossover. Did not change any values or anything like that. I do remember Moray saying the 1506 is a direct drop in for the stock driver and no values need to be changed or anything in the crossover. *That i remember. I think mine sound amazing. That large "magnitude" sound Dave said is a great way to explain the sound. 

 

Really sux i did all my mods at once but i really had no other choice. Even doing them like this took me over a month. I though it was tedious work, especially the bracing.

 

Well braced box has its documented advantages and i think they are true. I did the bracing, the felt, and added dynamat to the woofers struts-all things that could effect the bass. The bass did NOT get louder or hit lower. Bass seemed cleaner, more detailed, and tighter. I like heavy bass music so this was more apparent to me.

 

Big thing to look at is benefit to $ return ratio on these mods. I spent about 700$ in mods and countless hours of work. If for 700$ you can have speakers that sound better, from the bass to the highs, and music will be just that much more satisfying for decades to come it is a no brainer. I am not going to say these mods completely changed these speakers and made them sound MUCH better, but i would say bass and tweets sound 30% better. Pretty large improvement. This is all highly subjective and IMO.

 

You don't have to do all the mods at once. I think the 1506 is a solid, easy, and not to expensive mod. You can sell of the stock driver to make a little $ back, i did. This I think should be your first mod.

 

Just as important should be to biamp these babies. If your using a receiver you can do what i did and have the receivers amp power the tweets and get your self a proamp with gains knobs in the front so you can level match the tweets to the woofers (use receivers preout to feed signal to proamp,) you can do this by ear. SS amp for the woofers can be anywhere from 200 watts rms and up. Local CL would be a good start. Other way to go would be a preamp and two amps one for the Woofers and one for the tweets. You can try tube on the tweets if you decide this route  :)

 

Another thing, you MUST lift the speakers. I lifted mine two feet and i liked it. I personally like the WTW arrangement. In TWW arrangement you hear the music more separated with he highs coming from up top and the lows from the bottom. Most speakers are like this so people hear it and think it is normal. The cf4 WTW obviously the tweeter is in the middle and if you bring the tweets to ear level woofer firing just above and below your ear they imagine is a bit different, much nicer i think. I think this is a good reason why i love these speakers so much. 

 

This is my review of cf4 and khorn. https://community.klipsch.com/index.php?/topic/156526-cf4s-vs-khorns-review/?hl=%2Bcf4+%2Bkhorn

 

Hope i helped and goodluck!!

 

Alex

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"I bought a pair of DH1's at one time for my CF-4 project, but the throat used a 4-bolt pattern and I thought it was beyond me to make it fit.  Is the DH2 the same basic CD with a screw-on throat? "

 

No, the DH1 has a 3" diaphragm, the DH2 has a 2".

 

The DH1 has better HF, but you woun't be able to use it.

 

"what are you saying about the two models? "

 

The terminated tube on the 1506 shows it is 15dB down at 10Khz, and 23dB down at 15Khz, with a big resonant peak above there.

 

The terminated tube on the DH2Amt shows it is 10dB down at 10Khz, and 15dB down at 15Khz, with no big peak beyond.

 

The 1506 diaphragm can be installed into the K63 driver, the DH2 diaphragm can be installed into a 1506, so the DH2 diaphtragm should be able to be installed into the K63 driver.

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Well braced box has its documented advantages and i think they are true. I did the bracing, the felt, and added dynamat to the woofers struts-all things that could effect the bass. The bass did NOT get louder or hit lower. Bass seemed cleaner, more detailed, and tighter. I like heavy bass music so this was more apparent to me.

 

Agree completely with Alex.  When I braced my CF3s and put the felt & dynamat in, I noticed the same change.  Nothing got louder, but it was much more clean/detailed, the boominess was gone, and it was noticeable.  I did not do the EV DH1506 mod right away (actually undertaking this one now), but I did send the networks to Crites for re-capping.  Alex is right though, get them up off the ground so that you're looking down the throat of the horn...makes a signifcant difference. 

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After you replace the capacitors, replace the resistors with Mills non-inductives. Yes, yes, it sounds stupid, but do it anyways. Look at this way, if it doesn't do amazing things, you get the pleasure of coming back and telling me what an idiot I am.

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After you replace the capacitors, replace the resistors with Mills non-inductives.

 

 

It looks like there are a lot of resistors. In your opinion, is this a job an amateur could do?  I have soldered resistors in a DIY XO, but I don't have much confidence in my skills.  I have also never de-soldered anything.  Just based on my own pure ignorance, I'm guessing that's another area its really easy to screw up.

 

post-58280-0-82100000-1431961580_thumb.j

post-58280-0-31500000-1431962842_thumb.j

What resistors are you suggesting?  I did not see anything from PE that was even close in Mills resistors.

http://www.parts-express.com/brand/mills-resistor/253?N=4294963624+4294967118+4294963629&No=0&Nrpp=16&Nrs=collection%28%29%2Frecord[endeca%3Amatches%28.%2C%22P_PortalID%22%2C%221%22%29+and+endeca%3Amatches%28.%2C%22P_Searchable%22%2C%221%22%29]&PortalID=1&brandSelected=t

 

Maybe this is the correct Mills match?

http://www.soniccraft.com/product_info.php/ohm-mills-mra-10-p-3644

 

Does the Dayton Audio 10w3u resistor ($1.09) stand up the the Mighty Mills ($4.40)?

http://www.parts-express.com/dayton-audio-dnr-30-3-ohm-10w-precision-audio-grade-resistor--004-3

 

Notes:  The other resistor that you can't see on the top mount is 10W7u. 

post-58280-0-43420000-1431963645_thumb.j

FYI the stock XO was assembled in Mexico.

Edited by wvu80
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The prevailing idea here and elsewhere is that there isn't much of a difference between resistors and most capacitors as far as affecting the sound goes. When you DIY, you're in the perfect position to find out for yourself. Sometimes, I'm forced to use something else, but when I am, I'm not happy about it -- Mills resistors take some of the edge off and the sound is a little more refined. If you can afford to do it, do it. replace the capacitors first, and after a week or so, go after the resistors. Then you can sit in the chair and spend an evening telling yourself that it's placebo.

Edited by Crankysoldermeister
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Dave, those boards separate and let you work on them fairly easy, although rather tight in space.  I replaced all of my CF-3 resistors with Mills 12w versions and have used Mills resistors with Solen caps for maybe 25 years in home and car audio with outstanding results.  I thought I had posted pictures on here of that...I'll have to look.  

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Yep....found it.

 

https://community.klipsch.com/index.php?/topic/152523-klipsch-cf-3-crossovers-updatedmuch-better/

 

Check with PartsConnexion for a great selection of Mills resistors; that's where I usually get mine from unless PE just happens to have them.

 

http://partsconnexion.com/resistors_mills_mra12.html

 

I'd be glad to help you out with the crossovers in your CF-4's if you decided to redo them.

Edited by avguytx
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If you can afford to do it, do it. replace the capacitors first, and after a week or so, go after the resistors. Then you can sit in the chair and spend an evening telling yourself that it's placebo.

 

You know, I might just do that, in exactly that way.

 

I've spent months making one little change at a time, and listening to each of the differences in sound (if any) just for the sport of it.  I try to be brutally honest with myself, but sometimes I'm just not sure what I'm hearing.

 

I'll leave it to others to tell me its a placebo.  :P

(and they might be right!)

Edited by wvu80
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Dave, looks like its time to work up a parts list ;-). I probably need to buckle down and conspire with you on this...

Filippo

 

Give me a couple of days.  I have a CF-3 XO coming so I will be able to take it apart so see what we have.  We will put our collective heads together to see if there is any advantage to changing any values.

 

I will try to make a list of what is recommended for the XO on the DH1506 spec sheet, and compare it to the values we find in the CF-3/4 XO.

 

When Alex had his XO done he simply turned it over to the pros and he was very happy with the result.  I like to go a bit slower because this is all a learning exercise for me, and I like that part of it.

Edited by wvu80
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You do realize that those values are for ahead of the amplifier?

 

Not at the loudspeaker?

 

No, I had no idea.

 

I just glanced at the specs on the DH1506 spec sheet, but since I don't read electrical drawings I didn't spend any time really reading it.  It sounds like you're saying I'm not going to get any useful values for our purposes.

 

And what it really sounds like what you are saying, is if I keep going like this, I am really going to screw things up!  :lol:

 

You know, if you want you can offer some helpful suggestions.  I promise I'm listening.  B) 

 

I can only guess what you're going to tell me.  :rolleyes:

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