peteward Posted September 23, 2007 Share Posted September 23, 2007 I have a pair of Forte IIs. A couple of years ago I got Chris Munson to make me some improved crossovers and these have been excellent. I mounted them outside the cabinets. I'm now wondering about improving the absorption inside the cabinets. I used some cut up Deflex panels on the insides of the woofer basket and this definitely helped. I was wondering whether to remove the foam "wrap" that loops round the top of the cabs and fully line the cabs instead with Deflex. However, I've read that 100% isn't too effective, and that Whispermat can be better. Unfortunately I don't think there's a UK supplier for this. So before I start experimenting with various materials, I'd like to know if anyone has tried changing the absorption in Forte IIs. If so, what did you use? Any pitfalls? Anything I should definitely NOT use? Thanks for any help! Peter Ward Quote Link to comment Share on other sites More sharing options...
mas Posted September 23, 2007 Share Posted September 23, 2007 What are you trying to do? In other words, what is your goal? Cabinets are tuned enclosures. And except to address anomalies in the design of the cabinet (including internal reflections), one wonders what you are trying to accomplish... What you might do is obtain the measured Thiel-Small characterisitcs of the woofer and calculate the optimal enclosure for the tuning you desire. You may be able to modify the existing enclosure, or you may want to build another enclosure. In a rare instance you may be able to affect the apparent enclosure volume in order to fine tune the enclosure's tuning. But without a specific goal to be accomplished (or problem to be solved), why would you want to play with the internal cabinet absorption? Quote Link to comment Share on other sites More sharing options...
DrWho Posted September 23, 2007 Share Posted September 23, 2007 Changing the absorption in the cabinet will change the Q of the tuning point. It is also used to help reduce standing waves, but I have a feeling Klipsch has already got the basics covered. If you're tweaking your system for tweaking sake, then I might encourage persuing other avenues of expression. Like maybe room treatments for example? Quote Link to comment Share on other sites More sharing options...
peteward Posted September 24, 2007 Author Share Posted September 24, 2007 OK, thanks for your comments. I guess I'm trying to make the sound cleaner. The cabinets vibrate along in time to the music and I'm sure that's not ideal. I'm assuming that by changing the absorption material I can reduce the amount of internal vibration that reaches the wood, and therefore reduce the cabinet vibration. I had a pair of Lowther Acoustas once. I placed a Deflex panel directly behind each driver and the sound was much improved. I believe this was due to reducing the reflection from the wood panel immediately behind it. There is quite a lot of bare wood behind each bass driver in the Forte II. Perhaps it's fine as it is. If you've tried various options and heard no improvement that's very useful to know. If, on the other hand, the existing foam sheet that goes round the top half of each cabinet is simply a cost-effective solution that does a "good enough" job, then I think it might be worth some experimenting. After all, we know that everything's built to a price. Quote Link to comment Share on other sites More sharing options...
dtximages Posted October 5, 2007 Share Posted October 5, 2007 I totally agree. Ive always felt weird about talking about the quality of my Chrours/Fortes.. Then taking them appart and the drivers appear so cheap and the foam is just thrown in the cabinet. A couple of things though. Its a sealed cabinet so the effects will be less than if it were open. Also, I experimented with a klipsch kg 5.5. I lined the whole inner cabinet with foam by stapling it to the wood (sparingly as not to diminish the effect of the foam). I heard little or no difference. If i did hear a difference it was all in my head. Sometimes when we make tweaks we want to believe it sounds better so we think it really does. Anyway, I also feel like the sound isnt as tight as it should be due to cabinet resonance. I dont like the wood moving so much. I think klipsch should employ some kind of internal bracing along with high quality and strategically placed foam. This would probably change the size of the speaker etc but this line of speakers sounds sooooo good. I would love to hear them with some real high end componets and internal structures! Some ideas/complaints that I think negatively effect this line: Cheap plastic horns Paper woofer (they seem to work fine but i would like to have a better woofer.... we complain that bose uses paper ya know?) Unsturdy woofer/passive basket (thing resonates) Poor foam placement Poor cabinet bracing (mainly on chorus becuase its so much larger) Cheap internal wiring going to woofers. Makes good cables worthless. We have to remember, this is NOT cheap speaker. And also, with all my complaints listed above,, I still freakin love them!!!!! I just wondere if done correctly, could they be better? It just seems like too many people on here can improve on klipschs quality (difference xovers, foam placement, dynamat on basket/horns). Kinda concerns me that us amateurs can so easily improve a set of $2000 speakers. Quote Link to comment Share on other sites More sharing options...
djk Posted October 6, 2007 Share Posted October 6, 2007 "Cheap plastic horns" I agree. I liked the metal ones better. They ring, but you can damp them. The plastic lacks rigidity. "Paper woofer" Paper is better than plastic. Fiberglass, Kevlar, and Carbon fiber are all similar sounding because the rigidity comes from the plastic resin holding things together. "Unsturdy woofer/passive basket (thing resonates)" Damping the woofer basket can help, not sure if it is worth doing the passive. "Poor foam placement" Foam is cheap and easy to use, just toss it in. Not sure it is the best thing to use though. "Poor cabinet bracing (mainly on chorus becuase its so much larger) " The back of an original Forte really cruises at high volume. The first time I got the cabinet back to 'clank' against the midrange driver I disassembled the pair and wedged a piece of high density neoprene sponge between the midrange magnet and the cabinet back. No more 'clank', and less cabinet 'mud'. "Cheap internal wiring going to woofers. Makes good cables worthless." The biggest problem is not the cheap wire, but the push-on connectors. Cut them all off and solder the connections. I first did this on a brand new pair and I was stunned at how much this changed the sound. I doubt the connections improve with age. Quote Link to comment Share on other sites More sharing options...
dtximages Posted October 6, 2007 Share Posted October 6, 2007 Did you really hear a difference by soldering the connections to the speakers?? can you describe the difference? I wouldnt have thought that would actually change the sound. .but if it does then thats a pretty easy fix.. until you want to take the drivers out of course. Quote Link to comment Share on other sites More sharing options...
djk Posted October 7, 2007 Share Posted October 7, 2007 "Did you really hear a difference by soldering the connections to the speakers?? " Oh yeah. " can you describe the difference?" The speaker now sounds quieter, cleaner, and seems less efficient! More musical detail may be heard on quieter passages. The stereo image is more solid, and does not wander. " until you want to take the drivers out of course. " I own a pair of wire cutters. The wire becomes 3/8" shorter each time you have to replace a driver. Quote Link to comment Share on other sites More sharing options...
dtximages Posted October 8, 2007 Share Posted October 8, 2007 hmmm very interesting.. quiet is good.. I crunk out some cd's the other night at about -5db on the receiver and too much hiss. Mine probably comes more from my $150 dvd player and receiver. its a $2500 receiver but still. I always like to get away from hiss. I wander how my soldering skills are. Last time I tried was not pretty. I think i need to play around with room treatments before moding the speakers any. My room is terrible. Contrete walls, concrete slab with some rugs. The only positive is my ceiling is open with exposed floor joists. That offers some rigidity to the room but not quite enough. Ive been inaculated with roomtreatment ideas on here by people who are smarter and have more experience than i do... and i appreciate it all.. but wow overwhelming. Quote Link to comment Share on other sites More sharing options...
peteward Posted October 8, 2007 Author Share Posted October 8, 2007 Nice to hear some more positive comments . I've damped the baskets on the woofers and it helped clarify the sound. I've thought about soldering the wire to the tags but I'm hesitant due to my soldering ability. Now you've mentioned it I'll have another think. Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted October 8, 2007 Share Posted October 8, 2007 If you're not very good at soldering, DO NOT TRY THIS- if you heat up the basket wire enough you can damage the voice coil former, especially in mids and tweeters. Re the foam- do you think that possibly the Klipsch engineers tried all variations, ran them in the anechoic chamber, and preferred the method that you see in front of you? [hits forehead with heel of hand] 'Darn, we forgot to put foam in that last speaker design' yeah, right Michael Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted October 8, 2007 Share Posted October 8, 2007 Changing the absorption in the cabinet will change the Q of the tuning point. It is also used to help reduce standing waves, but I have a feeling Klipsch has already got the basics covered. If you're tweaking your system for tweaking sake, then I might encourage persuing other avenues of expression. Like maybe room treatments for example? If your room is acoustically troubled, how do you expect a change like soldering a wire connection to make a big difference? You could possibly start by orienting the horns properly and eliminating multiple sound sources. The comb filtering and phase anomalies have to be turning the soundstage to mush. Doc is wise, follow the grasshopper. Quote Link to comment Share on other sites More sharing options...
mas Posted October 8, 2007 Share Posted October 8, 2007 Changing the absorption in the cabinet will change the Q of the tuning point. It is also used to help reduce standing waves, but I have a feeling Klipsch has already got the basics covered. If you're tweaking your system for tweaking sake, then I might encourage persuing other avenues of expression. Like maybe room treatments for example? If your room is acoustically troubled, how do you expect a change like soldering a wire connection to make a big difference? You could possibly start by orienting the horns properly and eliminating multiple sound sources. The comb filtering and phase anomalies have to be turning the soundstage to mush. Doc is wise, follow the grasshopper. Oh great, so now we have someone dengrating magic solder. I can just see it, next you will denigrate magic wire!!! [] I just love solutions looking for a problem, any problem! Quote Link to comment Share on other sites More sharing options...
djk Posted October 8, 2007 Share Posted October 8, 2007 "If you're not very good at soldering, DO NOT TRY THIS- if you heat up the basket wire enough you can damage the voice coil former, especially in mids and tweeters. " This is a good point. "If your room is acoustically troubled, how do you expect a change like soldering a wire connection to make a big difference? " I guess he should give up and buy a pair of Bose then? "Oh great, so now we have someone dengrating magic solder. I can just see it, next you will denigrate magic wire!!! " FYI, I used ordinary 63/37 and the cheezy wire in the speakers. Quote Link to comment Share on other sites More sharing options...
mas Posted October 8, 2007 Share Posted October 8, 2007 "If you're not very good at soldering, DO NOT TRY THIS- if you heat up the basket wire enough you can damage the voice coil former, especially in mids and tweeters. " This is a good point. "If your room is acoustically troubled, how do you expect a change like soldering a wire connection to make a big difference? " I guess he should give up and buy a pair of Bose then? "Oh great, so now we have someone dengrating magic solder. I can just see it, next you will denigrate magic wire!!! " FYI, I used ordinary 63/37 and the cheezy wire in the speakers. My post regarding solder and wire was in response to Michael's earlier post advocating acoustical sanity (now there's an oxymoron) via an allusion to the too common debates over magic wire on this site. It was intended with a rolling of the eyes...It was a facetious allusion to someone knocking a supposedly magical solution which is in fact specious... The 'cheesy' internal wiring is just fine. But you might as well buy Bose, and Monster for that matter, if you think their marketing hype will make a critical difference. Yup, we don't need no "cheesy wiring"! LOL!! But beware, better solder may make you speaker "seem less efficient"!!! Huh!? [] Oh, and as the intended humor and point will be missed in the last comment as well. This is feigned objection to others criticizing still MORE nonsensical 'solutions' at which so many are quick to throw their money. Its pretty bad when dry humor simply sails over so many heads without even the vaguest hint that is understood. [*-)] Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted October 10, 2007 Share Posted October 10, 2007 MWM's have standard 18 guage zip cord inside. geesh fellas, didn't mean to start anything, but I think we collectively made our point. [8-|] Quote Link to comment Share on other sites More sharing options...
djk Posted October 10, 2007 Share Posted October 10, 2007 "But beware, better solder may make you speaker "seem less efficient"!!! Huh!? " Yeah, I don't understand it either. It seems to be mainly a low volume thing. If you crank it up they seem to be OK. Quote Link to comment Share on other sites More sharing options...
peteward Posted January 9, 2008 Author Share Posted January 9, 2008 Just to wrap this up, I finally got my new setup up and running and have been able to listen to it. I made more than one change so I can't point to the effects of a single change. I placed 3 Deflex panels on the bare lower panels of each of my Forte IIs, swapped to new crossovers (both new and old made by Chris Munson), and swapped to anti-cables for the internal wiring. The effect of all 3 changes has been to provide deeper and tighter bass, clearer sound and better stereo separation. I don't hear any downside. I would definitely recommend these changes. I think Chris's crossovers are beautifully engineered, while the anti-cable speaker cable is very quick and clear. Quote Link to comment Share on other sites More sharing options...
Islander Posted January 9, 2008 Share Posted January 9, 2008 Materials like foam, or in some cases, fiberglass batting, are added to speaker cabinets to provide "virtual volume", and are part of the design and tuning of the cabinet. They're not a random effort to reduce echoes, and adding more absorptive material is not a substitute for better cabinet bracing. Upgrading crossovers can provide a definite improvement in the sound of a speaker, but adding or subtracting material the cabinet was designed to have is really shooting in the dark. Quote Link to comment Share on other sites More sharing options...
dbflash Posted January 9, 2008 Share Posted January 9, 2008 i also added deflex panels to my cornwalls and heresy's and rewired them. i removed the batting in the cornwalls and replaced it with the deflex panels. the heresy's had no batting so i installed the deflex panels the same as the cornwalls. i used dh labs silver sonic t-14 speaker wire. the xovers still are stock 1978 type e/ type b. i agree with your findings about tigher bass and clearer sound. hope you enjoy your speakers. danny Quote Link to comment Share on other sites More sharing options...
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