OzBrit

Yes its all very interesting I am convinced the RF8000's can be taken to another level I have already done a preliminary build using a prototype 2.5 crossover solution (thats the kit promoted by a well known YouTuber who does crossover mods. You can see him on the AudioCircle forum but if I mention his name on here the post seems to get taken down. Not surprising really as he slates Klipsch - probably unfairly in my view - to promote his kits). What I did was reverse engineer his crossover and used parts probably very close to his proposed solution. A large inductor on the bottom woofer, a 1.3mh on this second woofer with a second order slope plus notch filter and 6.6uf cap on the tweeter with an LPad to bring levels down about 3-4dB. The result was a flat response at both 1 and 2 metres, much improved over the original. And distortion hadn't taken a hit either (my fear of using a first order). But having said all that a quick audition found that although the modified speaker sounded very smooth and balanced as it had lost a lot of its get up and go. It sounded very different (and I mean very) to the original. It reminded me of when I first auditioned the speakers at the dealer. In the listening room which was dedicated to Klipsch the whole RP series was lined up . In the mix was a B&W tower and each speaker could be remotely switched. Changing between the RP8000 and the B&W was like being moved from the front row of the concert right to the back row of of the upper circle! The sound difference of the 2.5 versus original was not subtle and at that point I did not want to go further and build the prototype for the second speaker. I did move on a little from this point and moved the crossover back a standard 2.0 configuration keeping the crossover tweeter as a first order and removing the Lpad, just leaving a 5 ohm resistor in series with the capacitor. I played around with the second order filter a little to try and minimise the 1-2K notch (which I could do). Listening to the this comparing with the original the sound signatures were more similar than different, as you would expect really. At this point it was the end of the weekend and I put the speaker back to its original state. So my conclusions are (i) the 2.5 solution, whilst flattening out the response, changes the sound signature quite significantly. I think the 'Klipsch sound' comes a lot from having very large bass mids (two 8 inch woofers equate to a single single 12-15 inch in surface area) and a horn or horns for the upper ranges (a la Heritage range). Taking out the second woofer just for low bass takes it away from this equation and probably makes the speaker sound like 'just another tower'. I maybe wrong here but thats the impression I get and would explain why Klipsch go for this formula in all their towers. (ii) the crossover as a 2.0 probably can be improved to at least reduce that mid range notch (iii) the tweeter on the RP8000 is a cracker. Taking the filter down to a first order doesn't seem to phase it. Incidentally I did measure the native tweeter response and its very smooth. No obvious honks or resonances aces like in earlier Klipsch horns. I need to do more work on this. I haven't discounted any solution yet including the 2.5 but to do it properly I need to take the crossover out of the enclosure so I can easily do the changes and try different crossover schemas. Thats my next step on this but this is all very time consuming so would love to hear back from others especially micromara Heres hoping for some useful feedback Cheers for now

As a newbie here I would like to start a new topic on updating the RP8000. I know a few of you here have already been down this track and I am hoping to share in other people experiences as I embark on my own project. I have had my RP8000's for just over a month and even before I unboxed these I was expecting to do an update on them. Now don't get me wrong I think these are very good speakers as is and I would not hesitate in buying them a second time round if I had my time again. The sound, once run and properly positioned in the room, is very good. The sound signature is dynamic and forward without being too bright with very good wide imaging and a full bass thats not too flabby with reasonable speed. Voices sound full and detailed and instruments are well separated across the sound stage. As far as usage goes I find positioning critical and I certainly wouldn't use these in a small room. My room is 12 by 6 metres and I find to get the best sound you need to be 3m or further from the speakers, have the speakers well away from the walls and toed in directly pointing at the listener. That all said I am a DIYER and I like to get the best out of my equipment. I have done a couple of my own speaker builds in the past and I know these speakers can be taken to another level so here's my thoughts:- 1. Theres definitely room for improvements in the cabinet and I can hear some effects on lower range cabinet resonances in certain bass notes and in the lower mid ranges. 2. Doing a quick REW measurement the well documented dip in response at crossover is there. This features as a 5db drop in the 1-2 K range, see the REW graph below. Quick measurements of the woofer and tweeter circuits are shown as wells the speaker as a whole. Measurements are taken at a approximately 1 metre in room at tweeter level. I think this dip is audible and taking it out I think will improve mid range clarity. 3. Looking at the crossover components the Woofer inductor is of average quality (1mm iron core) and could be improved with a good quality air core. The woofer circuit also uses quite a large capacitor to increase the slope to take out ringing in the woofers (looks like in the 4-6K region). This could probably be improved by reducing the slope and using a notch filter to take out the ringing. The capacitors look of reasonable quality, probably cheap polypropylene or maybe only polyester I'm not sure. Of course better quality caps or maybe bypassing with some Miflex copper foils would improve over sound quality across the board but also a complete crossover redesign might be better. I'm not sure at this stage? 4. Better connectors and wiring will probably help (in the margin) I've looked at other online posts on here and other forums. On this site user micromara has documented his cabinet rebuild. The results look very impressive but I'd be really interested on hearing anyones views on adding additional panel support and foam based damping as opposed to using the fibre damping down the middle of the cabinet. How does the former change the sound over the original implementation? As far as the crossover goes I've been looking at an online 2.5 redesign and takes the second woofer out of the mid range using a massive inductor so it only plays below 200Hz. The tweeter circuit is taken down in frequency and goes from a 4th to 1st order solution. On paper this all looks good but I have some concerns about having the tweeter playing on a 6dB octave rolloff. A lot more low end energy going into it and what effect will this have on distortion I don't know (even the tweeter possibly failing under high loads)? So anyone who has done crossover mods, well their feedback will be gratefully appreciated. I plan to start my own research and will start by prototyping some changes to the crossover. I have all the components to measure the changes of using the 2.5 solution. I'll document this as I go along but any feedback on people who have already done these changes. Well that will be very useful Cheers for now