pzannucci Posted March 19, 2014 Share Posted March 19, 2014 I have a set of KLF-30s that are in need of a nicer looking cabinet. Since I will likely be restoring them I have been contemplating the use of 3 or 4 12" passive radiators tuned to around 27 hz or so. Questions: Anyone know the xmax of the K-31 woofer so I can add the proper number of passives? Will I loose or gain over the original ported design - basically is this a bad idea - thoughts? I will be making the cabinet the appropriate size considering the tuning but I am wondering about the quality of the sound and amount of low bass compared to the ports on the KLF-30 stock. I am thinking of using the P-E Dayton 12" passives with an xmax of 10mm. Thanks. 1 Quote Link to comment Share on other sites More sharing options...
pzannucci Posted March 21, 2014 Author Share Posted March 21, 2014 Anyone have any thoughts about doing this (adding the passive radiators) and if it would be worth the cost for better low bass? 1 Quote Link to comment Share on other sites More sharing options...
Scrappydue Posted March 21, 2014 Share Posted March 21, 2014 man i am not real smart about modding speakers or the diy thing yet. however you ask for an opinion so i will chime in since no one else has. i think it would be a bad idea for a few reasons. first reason is you would only be getting a few hz lower. most likely won't be even audibly noticeable. second is who knows how much extra it will all cost. third is you might make a already "great" speaker sound terrible? there it is. good luck if you do it. let everyone know, you for sure will have some one of a kind speakers. 2 Quote Link to comment Share on other sites More sharing options...
Sancho Panza Posted March 21, 2014 Share Posted March 21, 2014 Tend to agree with Sd. If it were me, I'd want to know what Moray James thinks. Quote Link to comment Share on other sites More sharing options...
pzannucci Posted March 21, 2014 Author Share Posted March 21, 2014 Thanks for the thoughts. Since I will be just doing a moderate increase in the cabinet volume and not likely changing the crossover, these changes should just affect the extension and output level of the low bass not the overall character of the klf30. I would also like to find out if anyone thinks the ports would provide better output than the passive radiators. I believe most companies don't do passive radiators because of the increased cost and also it helps them sell sub-woofers. If you have a truely full range speaker, many would forego subs. On the cost front, some wouldn't pay the cost for the passives. This is likely why speakers such as Chorus I went from ports to passive in the Chorus II. Also Forte went from a 12" to 15" for better coupling. Many don't think they need subs with Forte IIs. If I can get a solid 25/26hz out of them for $130 each, I'm not sure it is a bad proposition considering I don't have a good space for a sub, particularly since I use only 2 channel. Thanks again for opinions. 1 Quote Link to comment Share on other sites More sharing options...
Sancho Panza Posted March 21, 2014 Share Posted March 21, 2014 Peter I like the way you're thinking, especially your last statement above. Quote Link to comment Share on other sites More sharing options...
moray james Posted March 21, 2014 Share Posted March 21, 2014 why don't you simply experiment with extending the length of your KLF30 vents? You can use a simple roll of construction paper and a little tape. Find the length that works best and then contrive more rigid cardboard or plastic vents of that length. You will likely end up with a new vent of about double or less than the the existing vent length. Passive radiators are very expensive. you can do the process totally by ear. Best regards Moray James. 2 Quote Link to comment Share on other sites More sharing options...
pzannucci Posted March 21, 2014 Author Share Posted March 21, 2014 (edited) why don't you simply experiment with extending the length of your KLF30 vents? You can use a simple roll of construction paper and a little tape. Find the length that works best and then contrive more rigid cardboard or plastic vents of that length. You will likely end up with a new vent of about double or less than the the existing vent length. Passive radiators are very expensive. you can do the process totally by ear. Best regards Moray James. What I am attempting to find out is quality, quantity, and depth of response when using 3 12" passives compared to the 2 3" ports on the KLF-30. These have 3 12" passives and are solid down to below 30hz without the typical smaller port drop off. I wish now I had tested ports compared to passives. Edited March 21, 2014 by pzannucci 1 Quote Link to comment Share on other sites More sharing options...
SWL Posted February 10, 2015 Share Posted February 10, 2015 pzannucci, Did you ever go through with this? Quote Link to comment Share on other sites More sharing options...
moray james Posted February 10, 2015 Share Posted February 10, 2015 Anyone have any thoughts about doing this (adding the passive radiators) and if it would be worth the cost for better low bass? just a rough guess on the peak to peak I doubt if it is much more than 6mm for the stock driver so for passives a peak to peak of 10-12mm or more ought to be lots.Sounds like an ok Idea why not find some low rent woofers with approx. the fight Fs ans use them as passives way cheaper than buying passives. That is the main attraction to vents they are almost free.I would expect vents and passives to sound pretty darned close in sound quality. Best regards Moray James. 1 Quote Link to comment Share on other sites More sharing options...
pzannucci Posted February 12, 2015 Author Share Posted February 12, 2015 pzannucci, Did you ever go through with this? I am still contemplating a rebuild. Lot of other projects to work on. The other reason I haven't done this is that I am trying to figure out which I want. - I have 2 klf-20 woofers in a 5.5 cf box with somewhere around a 16"x3"x17" long slot port in them. Tuned around 31/32hz (discussed with Moray before). These sound ALIVE. The KLF-20 woofers are very good. - I have the 8 or so cubic foot box with two Focal 13v woofers in them with 3 12" passives on the back - the picture. They sound smoother and deeper though maybe not as LIVE. I can't put my finger on it. I may end up rebuilding the klf-20 woofer enclosures because I am transitioning to a home (slowly) that won't accommodate the 24" deep klf-20 woofer enclosures. I may end up with using 3 12" passives with the two 10" woofers, not tearing apart the klf-30s and selling the homebuilts in the picture. The SO thinks the homebuilts are too big for the location they are at. Still undecided. About the inexpensive woofers, I have been using the 12" passives from P-E. Actually very good for the $34 each price. Quote Link to comment Share on other sites More sharing options...
moray james Posted February 12, 2015 Share Posted February 12, 2015 Peter: I believe that there is a lot of untapped refinement in the Klipsch woofers and I especially like the KLF20 woofers. Not sure if you are interested in the work involved but you can shoot me a PM and I can give you the info so you can at least consider if it is worth thinking about for you (rater than bore folks here with it). Funny one of the single biggest improvements to the sound of my H3 was the addition of an EV DH1A to replace the mid and tweeter. The woofer crossover section was left untouched and the DH1A dropped into place via a CF3 network section. Sounded like there were double the number of woofers playing with the very much better compression driver in place. Truly brought new meaning to the expression "sudden impact". Twenty three and a half pounds of wow. Shoot me a PM if you are at all interested in the woofer mods. Best regards Moray James. Quote Link to comment Share on other sites More sharing options...
cradeldorf Posted February 13, 2015 Share Posted February 13, 2015 (edited) I got more live sound by removing the port tubes, although I'm sure most will claim I lost the lowest of the LF I don't miss it. they go plenty deep enough for me. But sounding perfectly live was a bigger perk to me. If you do change the box shape the crossover will probably be off as the baffle step is calculated into them. Stick to the factory width of the cabinet and you should be okay. Moray, I could never be bored by ones ideas and results from trying to better the sound of their system. Edited February 13, 2015 by cradeldorf Quote Link to comment Share on other sites More sharing options...
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