Jump to content

Epic CF3 Bracing & Damping Project


kapsnb01

Recommended Posts

Damping was done using 1/8" thick F11 felt that I bought from Amazon. I attached it using 3M spray adhesive, which seemed to work very well. Tried to match up the volume of F11 to be similar to that of the original factory damping material.

Link to comment
Share on other sites

  • Replies 84
  • Created
  • Last Reply

Top Posters In This Topic

  • 2 weeks later...

Thought I'd post an update and a little more information for any who are interested.

I changed around the damping over the weekend a little bit. The damping is now around the woofers to form a little chamber. Specifically, I created a box of damping material that splits the cabinet roughly in half and runs both above and below the woofer. So, each woofer has it's own little chamber. This seems to work much better and I noticed the difference from what I had immediately. I might play with it a little more in the coming days/weeks, but it'll be more to confirm that I've got it the way I want than to actually change anything. I'll try to get some pictures up soon to show what I'm talking about.

In my haste to post what I was doing, I didn't do a very good job talking about what materials I was actually using. For the cabinet bracing, I used 3/8" baltic birch plywood and attached it to the cabinet with carpenters wood glue. The stringer braces were simple 1x2 pine and also were attached with wood glue. I also swapped out the factory wood screws with machine screws, so I used epoxy to glue in the machine screw inserts. So, all my woofers, horns, and networks are now attached this way. This works well, especially with the number of times that I've taken off the woofers/horns to trial damping and such.

At any rate, I hope this thread is helpful for anyone that might be considering a similar project. To me anyway, it was certainly worth the time and effort. Will try to keep updating with any additional mods/upgrades that I do.

Link to comment
Share on other sites

Great work Brian! I'm Brian to haha. Plus we have Cf3s, funny stuff. And I grew up Minnesota south of Duluth in the sticks far from an audio store. Reception was bad there. Maybe 4 radio staions and 3 Tv channels. Thats when music got me. Islolated in the woods with public radio classical and jazz. Worked all summer and blew it all at best buy for a pioneer system, what is now known as B.P.S. I was 14 and didnt know jack, but sure loved having 12 in woofers and a CD player.

Anyway I was hoping you could describe somehow how the sound changed after these Mods to the overall effect of the CF3s? Could you elaborate as to how they sound now? Bobs crossover/cap work may have off set some of the bracing and damping, yet combined did this yield a cleaner overall picture in the stereo effect? Are they so tight that only music presented with volume/power gets imaged? Or is it a mellowing, say controlled presentation. I know I'm all over the place, dont let me bug ya to much. Haha, well lets start there and I'll start digging thru my dowls and scrap wood to see if I can pound some framing nails into these coffin sized speakers. J/K!.... I think if this old welder works it'll be faster! hehe. Later B-

Link to comment
Share on other sites

Hey Brian - That is too funny...I probably grew up less than an hour from where you did. We actually had a small farm out in the sticks around an hour north of St. Cloud. Small world...where are you at now? I'm in the St. Cloud area myself. Wish I knew how much time and money I've blown at the local Best Buy over the years...funny how much you learn later on that would've been useful to you back then also!

I actually did the Crites work and the bracing at the same time. Just seemed to me that as long as the networks were gone for a couple weeks that it'd be the right time to do the cabinet work. I know that there are others that disagree, as it doesn't allow for true A/B testing. So, I have my suspicions on which of the modifications is causing certain dynamics, but I can't be 100% sure. At any rate, upon putting the networks back into the braced (but not yet damped) cabinets, the first thing I noticed was that the speakers were definitely brighter than they were before. I myself am convinced that this comes from the rebuilt crossovers. I listened to a fair amount of music before putting a shred of damping material in them and I found the sound to be cleaner and tighter than before. In songs that I had heard many times, I was hearing details and background sounds that I had not heard before.

After putting in the damping material, I immediately noticed an improvement in sound clarity. For this part, I did do a true A/B test and I could really tell a difference. Again, I heard additional minor details that I hadn't before. I'm sure I could just be hearing things...but, I have definitely noticed a difference.

To answer your questions though, I'm driving my speakers with the same power at the same listening levels that I had before and imaging is great. For lack of a better description, I think it just cleans up the sound and allows you to hear all of the finer detail that might get lost in some of the cabinet talk. Hope that helps...feel free to fire away with more questions if you've got em.

Link to comment
Share on other sites

I read on here that as crossover components age they become more resistant, resulting in (most noticeably) mid and high frequencies being lower in output. Replace/upgrade the components and their output is restored. Some people don't like how their speakers sound after doing this. A lot of times your ears just need to take time to get used to the change in sound.

Link to comment
Share on other sites

Yes wuzzer I agree. I will likely sell some old receivers and take 50 dvds and cds and sell them to raise funds for a cap job. I have a Iron and lots of line but i don't want to burn and screw up a one shot deal. Learning to solder for dummys is a book I do not have. Even tho I am trying to avoid brightness I do want speakers to reveal the information. So I did stop at the car audio place and a 1ft by 3ft piece of dynamat was $25. I told the owner that was to much but he suggested from experience that I should try the spray can Flex Seal liquid rubber as seen on tv stuff. He said they spray it in hard to reach places in vehicles for deadening. So off to Ace bought a 12 buck can of this stuff. Maybe I should have bought the dynamat? Well its sunny and 50 today so my 4 tractrix are going to get sprayed with this rubber stuff. I'll report back if this crap works. I can always put damping material over it if needed. I'll report back on that.

And Brian, I grew up by Sandstone out in the 'sticks'. On a farm, chopped our own wood, drank fresh milk and hunted cute rabbits and pretty deer. Along the Kettle river I fished my lunch and carried a boombox everywhere. Haha, even had it strapped to front of my bike, I went hands free and played air drums to Phill Collins In the air tonight. I can still feel it lol. I ended up playing drums for 10 years after that. Go figure. Never made a mint jamming out but it was fun playing music in the barn with friends and family. To make a long story short I still love my land in Minnesota, But the wind blew us down to So Dak. I'm in a big city now and run a thriving catering business with my wife. I'm hella busy. There. I dont like to share info on the internet. But I also have an extensive shotgun collection, just waiting to blast the first fool to come in with out knockin' lol. I'll try to get some speaker work done this weekend.

Those Crites titanium diaphrams are a absolute bargain that I put in some 5.5s. The factory ones were horrible in comparison. Those play the highs well outside the speakers. Drums and effects were clearly panning the entire room last night. To bad they are not available for the CF series :( When I get the spare change I am definately going to buy new crossovers for 1 pair of my 5.5s, so sorry Klipsch I wont be buying new speakers from you anytime soon, Only the RF line generates interest from me and they are out of my price range. I'll stick to the classics. As for changing sound, every single recording is different. Even master tapes. I dont have an EQ anymore but it would be great to have one with a remote once your setteled into couch potatoe mode for a listening session. Purests scoff at eqs, and maybe I cannot find the time to hunt down or afford the rare premium recordings. The quest will never end my friends. Stay thirsty!

Link to comment
Share on other sites

Along the Kettle river I fished my lunch and carried a boombox everywhere. Haha, even had it strapped to front of my bike, I went hands free and played air drums to Phill Collins In the air tonight. I can still feel it lol. I ended up playing drums for 10 years after that. Go figure. Never made a mint jamming out but it was fun playing music in the barn with friends and family.

You should fit in perfectly here.[;)] Stick around, this is a great forum.

Link to comment
Share on other sites

And Brian, I grew up by Sandstone out in the 'sticks'. On a farm, chopped our own wood, drank fresh milk and hunted cute rabbits and pretty deer. Along the Kettle river I fished my lunch and carried a boombox everywhere. Haha, even had it strapped to front of my bike, I went hands free and played air drums to Phill Collins In the air tonight. I can still feel it lol.

Too funny... I miss my old boombox, had many a fun time jamming back in the day!

Link to comment
Share on other sites

Well heres my ham fisted Diy of the horn. Would have liked to get all the way down to the edge but it contracted upwards and would'nt stay. For a quick job its fine. But I think it could be better. I will try something thicker/dense like dynamat when i can find it cheap. I could just cut that foam off easy. The results seem to be the same after I sprayed the rubber on. Tighter dispersion at high volume. I seem to recollect seeing theater horns with heavily coated textured back sides. Can't remember where tho. I also ripped a stud for 2x2s and glued them in around the horn cutout area. These made a stout box to stiffen the front panel. Tucked a little fiberglass in the side area as well. This did help noticably in tightening bass. I did'nt run anything across or to the back as I had no 1x3s at hand. It seems putting some near the top of the cabinet would help resonance controll to. I have read several speaker bracing threads and may continue with that project, duh, it seems bracing to my ears does work to subdue the energy.

post-58804-13819831727092_thumb.jpg

Link to comment
Share on other sites

Glad to hear that the bracing has made a noticeable difference for you also. Certainly cuts the cabinet noise out of the equation. Keep us posted on how things turn out if you do some more bracing. Horn will be a project for mine at some point soon too...but, since it's finally starting to warm up around here, I think time will be tougher to find for speaker projects.

Link to comment
Share on other sites

Spent a little time doing A/B testing to see if there would be any benefit from adding more damping in behind the woofers. I think I've got it dialed in to where it sounds best (to my ears anyway). Thought I'd share a couple more pictures, for those that are interested. I've essentially cut the box in half with damping behind each woofer.

post-54723-13819832015294_thumb.jpg

Link to comment
Share on other sites

  • 2 weeks later...

I ended up replacing all 4 woofers with a new set at the same time as I modified the enclosure. So after some major upgrades and break-in, Ive hooked up a 250w @ 8ohm amp and almost cried when I heard a proper kick drum for the first time. Wow, it is so good. The top end was a bit bright with this particular amp so now I'm going to try bi-amping with a miniSHARC for a crossover. It's going to take some time tho.

Link to comment
Share on other sites

Damuffin: check your drivers and make sure the screens are clean and that the units are screwed together snugly not tight though just snug. If things still sound bright you should check the voicecoils. Use a wrap or three of skived plumbers teflon tape on the driver snouts to make sure they are well sealed. These are not hot tweeters in fact a common complaint is they are on the soft side so I would be suspect of possible VC damage given the speakers history. Ti diaphragms will provide more high frequency output so brighter again so if your balance is good with the aluminum then that is a good thing to know. I hope all is well with the diaphragms. Fine speake the CF3 now you know why I like it. Best regards Moray James.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...