lockedandloaded Posted November 13, 2002 Share Posted November 13, 2002 Just found a sheet of foam packing "sponge" inside the cabinets of my RF-7 speakers. Seems kinda low-tech for a reference quality loudspeaker. But I am never one to second guess the engineers. Can anyone explain the purpose behind stuffing this material into the cabinets? It actually was blocking the lower of the 2 bass ports. And it is easily removed. Is this stuff "tuneable" by adding more or removing it totally? What will it change on the speakers sound? Quote Link to comment Share on other sites More sharing options...
HornEd Posted November 13, 2002 Share Posted November 13, 2002 Actually, finding such material is quite common even in higher end speakers. Obviously, blocking a port is not its intended use. Building a world class speaker cabinet is not an easy engineering task... it is relatively easy to be "pretty good" at it... witness all the DIY speakers that please their owners but have little resale value. One of the prevalent speaker design concepts was the "infiite baffle" by which extraneous sound waves were allowed to reverbrate where they would not affect the sound heard. The "sponge" you found works on somewhat the same principle to soak up what would otherwise be unwanted sound wave reflections inside the box. Usually such elements are firmly attached to specific areas... so you might do a 1-800-KLIPSCH to discover where your errant sponges should be. -HornED Quote Link to comment Share on other sites More sharing options...
NOZ Posted November 13, 2002 Share Posted November 13, 2002 Great avatar ED! Quote Link to comment Share on other sites More sharing options...
lockedandloaded Posted November 14, 2002 Author Share Posted November 14, 2002 Anybody ever play around with this foam padding? Adding more, removing it entirely, trying different materials? What about gluing it into the cabinets as opposed to being just layed inside the bottom? Inquiring ears want to hear..... Quote Link to comment Share on other sites More sharing options...
Kain Posted November 14, 2002 Share Posted November 14, 2002 They are not meant to be blocking the ports. If they are, just push them in. Quote Link to comment Share on other sites More sharing options...
prodj101 Posted November 14, 2002 Share Posted November 14, 2002 the stuffing is very important. It may look low tech, but theres really no other wawy to get the same results that it has. It improves the bass, and reduces colorations caused by the cabnit. Quote Link to comment Share on other sites More sharing options...
Guest BobG Posted November 19, 2002 Share Posted November 19, 2002 That simple looking foam is a pretty high tech item. Quote Link to comment Share on other sites More sharing options...
timbley Posted October 3, 2004 Share Posted October 3, 2004 ---------------- On 11/13/2002 10:41:19 AM lockedandloaded wrote: Just found a sheet of foam packing "sponge" inside the cabinets of my RF-7 speakers. Seems kinda low-tech for a reference quality loudspeaker. But I am never one to second guess the engineers. Can anyone explain the purpose behind stuffing this material into the cabinets? It actually was blocking the lower of the 2 bass ports. And it is easily removed. Is this stuff "tuneable" by adding more or removing it totally? What will it change on the speakers sound? ---------------- If you reach inside one of the ports and touch that foam while music is playing, you'll find it vibrates considerably, while the cabinet itself has practically no vibration. In my RF-7 the foam does a sort of S-bend where it goes from laying flat on the bottom to curving up along the front of the cabinet oposite the ports, and then curving back to the rear of the cabinet above the ports to be on the back wall opposite the main drivers. I don't know what happens after that 'cause I can't see, but I'll bet it curves back to the front toward the top of the enclosure. This leaves the side walls of the cabinets untreated. Perhaps treatment of the side walls could provide some audible improvement. But these speakers don't strike me as being marred by cabinet resonance coloration. They sound great, so I'd not be inclined to want to mess with anything. Quote Link to comment Share on other sites More sharing options...
Dylanl Posted October 3, 2004 Share Posted October 3, 2004 Odd as it sounds the foam in my RF7's is also blocking the bottom port. I have felt it while the speakers are playing and youn can feel vibration. I called Klipsch about a yr. ago on this and they said it is in there to pick up any standing waves inside the cabinet. Mine also has an odd shape as described in an earlier post. About 6 months ago there was a thread in which someone packed their RF7's with more foam and stated the bass response was lower. Without tests to substantiate his claim he probably was caught up in his mod. and believed there to be a perceived difference. I think if you pack yours you will hear the same. It's just human nature. IMHO you are probably best just letting things the way they are. If these speakers needed more foam I think Klipsch would have added it. What would the cost come to, an extra $10.00. What is that based on a speaker that in the beginning sold for almost 2,000.00 a set. Quote Link to comment Share on other sites More sharing options...
nicholtl Posted October 3, 2004 Share Posted October 3, 2004 Wow, a 2 year-old thread resurrected. Quote Link to comment Share on other sites More sharing options...
timbley Posted October 4, 2004 Share Posted October 4, 2004 ---------------- On 10/3/2004 7:46:06 PM nicholtl wrote: Wow, a 2 year-old thread resurrected. ---------------- Oops! I was just curious about this issue myself, so responed to an old post. I've read books on speaker building that suggest more surface treatments should be made on the inside of the speaker. Strangely the two best sets of speakers I've ever had did not heed the idea of fully treating all the inside walls: these Klipsch RF-7s and a pair of speakers from a small time builder in Tacoma. He did a lot of things "wrong" by the book, but everybody that heard those little speakers really liked them. I had a pair of Polk SDA-2, I think. I looked inside and saw minimal stuffing, just a sheet of fiberglass hanging down behind the drivers. The whole bottom half of the speaker's insides was completely untreated. So, I cut carpet and lined all the inner surfaces with it. The result: The speaker sounded dead and muffled. It just didn't work. Quote Link to comment Share on other sites More sharing options...
lockedandloaded Posted February 12, 2023 Author Share Posted February 12, 2023 (edited) 20yo topic being revisited! Didnt even remember posting it until after searching for RF-7 foam insert. Try to keep this short, but I'm in a state of shock. When I made the original post, there weren't many RF-7 inquiries to the community being recently introduced. My pair are early manufacture with Monster Cable Z-Series® wiring & Cherry wood cabinets. Serial #'s 119/122. Since 2002, there's been many posts asking the same question about placement of the interior acoustic foam. One has a Klipsch engineer replying with the correct factory placement. Mine were 180 degrees offset, so only the 2 sides of the lower cabinet & bottom were covered. I just now repositioned the foam to factory spec. And Im blown away by the result! The sad part is 2 decades of not hearing my speakers perform to their potential. The exact moment realizing this was listening to Cheryl Crow's self titled album, the track Everyday Is A Winding Road. Having played this dozens of times before, I was speechless at the new sound coming from my beloved Klipsch. The imaging and soundstaging were so defined that upon closing my eyes, I could accurately hear where each musician was standing (Tchad Blake engineer of mixing). Previous listening sessions had lacked that attention to detail. My system is elderly, NAD C216THX 125w & C160pre, NAD CD545BEE, and 10' set of locally manufactured JPSLabs UltraConductor Bi-Wire cables. Recently added Klipsch Reference R-120SW sub that I'm still experimenting with placement and isolation. I'll wrap this up by saying its amazing how much difference the foam placement effects the sound, that it almost seems like I got a new set of speakers. Edited February 12, 2023 by lockedandloaded 1 Quote Link to comment Share on other sites More sharing options...
OO1 Posted February 12, 2023 Share Posted February 12, 2023 3 hours ago, lockedandloaded said: I just now repositioned the foam to factory spec. And Im blown away by the result! The sad part is 2 decades of not hearing my speakers perform to their potential I'll wrap this up by saying its amazing how much difference the foam placement effects the sound, that it almost seems like I got a new set of speakers. ..after 20 years , how cool can that be 1 1 Quote Link to comment Share on other sites More sharing options...
Peter P. Posted February 12, 2023 Share Posted February 12, 2023 It's not clear to me what the correct placement of the foam is; please give me a clue. Also, is it worth gluing the foam in place, even if a permanently tacky or repositionable adhesive were used? One wonders whether the OP's foam somehow shifted, covering the bass port. 1 Quote Link to comment Share on other sites More sharing options...
Marvel Posted February 12, 2023 Share Posted February 12, 2023 5 hours ago, lockedandloaded said: almost seems like I got a new set of speakers. It's too bad it took so long. Upside is you didn't have to spend money to get a new pair of speakers. Welcome back! 1 Quote Link to comment Share on other sites More sharing options...
billybob Posted February 12, 2023 Share Posted February 12, 2023 Welcome back @lockedandloaded ! 1 Quote Link to comment Share on other sites More sharing options...
lockedandloaded Posted February 14, 2023 Author Share Posted February 14, 2023 On 2/12/2023 at 7:17 AM, Peter P. said: It's not clear to me what the correct placement of the foam is; please give me a clue. Also, is it worth gluing the foam in place, even if a permanently tacky or repositionable adhesive were used? One wonders whether the OP's foam somehow shifted, covering the bass port. Use the search function and there is a hand drawn illustration in on of the threads. Cant recall which one. But pic is better than words. Mine came with foam partially blocking lower ports. When I originally moved them, did it incorrectly due to lack of info at the time. 1 Quote Link to comment Share on other sites More sharing options...
lockedandloaded Posted February 16, 2023 Author Share Posted February 16, 2023 The thread title is FOAM PLACEMENTS IN RF-7'S by rugerdog. The Klipsch employee replied that this diagram is correct, and is what I followed. 1 Quote Link to comment Share on other sites More sharing options...
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