sixspeed

No problem. But yeah, 150W is honestly more than plenty to adequately drive RF-7s. But there are other figures and specs besides pure power output that also play a role as well and this is how you can have multiple amps with a similar output rating perform very differently.

You should definitely give the Luxman 505/550 integrateds a serious look as well which are a couple grand cheaper than something like a Yamaha 3200 and are just as good if not better. The McIntosh and Accuphase "entry" level integrateds are also worthy of consideration. For Class D I wouldn't sleep on the TEAC AP-701B power amp which is much cheaper than other options, very well built with HQ parts. TEAC and its sister brands like Esoteric, TASCAM, Onkyo and Integra are now owned by the Klispch parent company FWIW. You'd need a preamp for it though. I'm not a fan of Class D for heritage but the Reference and RP speakers are a different story. Jeff Rowland amps would be a very good pairing for an RF7. Such as dual Rowland 125s as mono blocks in bridge mode if you wanna do mono blocks. Those will have plenty of power to excite the dual 10s on the RF7s which like a lot of current despite the high efficiency rating of the speaker. IMHO the RC-64 and RF7s are sensitivity overrated by around 5-6dB so think of them as 90/91dB speakers. High current/power, well measuring Class D tonally and amp pairing wise would be a great match. Lastly I'd give the Bryston B135 Cubed consideration as well.

I agree with some of the other comments. Perhaps for the future, a more car audio oriented or permanent/70v distributed audio like in ceilings spread around your RV for good coverage may be the way to go in the future. Personally, I prefer powered monitors for smaller speakers which benefit from built in protections and made for purpose amplification. The little JBL powered monitors, the 300 series would be a nice replacement if you want to try something else. I would also take a look at your receiver. It's distortion may be higher than ideal and perhaps it was never an ideal pairing for the 600 in the first place. A lot of the receiver makers now a days cheap out massively on the amp sections now. Especially as they have more royalties to pay out the more codecs and formats they have to support so in order to turn a profit they cut costs more. And all of it, like the 600s are made overseas in China, Vietnam, Malaysia etc. It's not the same as the Klipsch made in Hope. It's just not. But at least Klipsch still makes stuff here. A lot of JBL's higher end stuff is made in Mexico and China. Not gonna get anything ultra high quality in the more budget price point, but I can understand the frustration especially when you perceived to not driving them as hard as you thought you were. Clearly enough to blow them though. Small speakers are much more limited and easier to blow up regardless. Powered speakers might be a good alternative. Klipsch even has a few offerings and for outdoor maybe pick up one of their table top bluetooth speakers or even something like the new gig speakers if you want some decent volume for background while working outside. And use the 600s just for inside listening. Good luck.

The low watt Class A Pass amps seem to work best for Heritage of all Pass' designs. New McIntosh is very quiet as well. Something like a MC-152 if you want to stick Class AB would be a nice choice. The MA5200 I had, non-autoformer was very quiet and sounded wonderful, it's essentially the integrated version of the 152. A MC-152 or Bryston 2.5B3 would be on my personal shortlist if I were you. Both are direct competitors and priced the same in the $4800-5500 price point. Bryston has a 20 year warranty guarantee on all their analog gear. Yamaha I agree makes some very nice amps but most are integrated amps and their $10,000 flagship power amp was really designed in mind for a complete Yamaha 5000 series system with their NS-5000 speakers. If you want a warmer sound with arguably the nicest build quality in the industry with ultra low noise you should also give Accuphase Class A a look like the A-48 also priced the same as the Yamaha 5000. All Bryston amps have adjustable gain settings for SE or XLR input and pro models even have trim pots on the back. Amp pairing and digital front end electronics are even more critical on high efficiency speakers both for noise and how revealing they are showing off a particular components sonic characteristics for better or worse! I agree with the above that the higher power A/B Pass Labs amps by default are designed more in mind for lower efficiency conventional "box" speakers. Although I didn't know they offered a custom factory service when ordered new to tailor the gain for the customer, I agree the more "devices" in the amplifiers output stage path, the more distortion and noise that can get in there that won't get on well with horns. Heritage is super revealing of the front end electronics and can highlight the sonic differences between amp types and the house sound of various amp makes.

GLWS. Going for Heritage multi-channel?

Despite the similarities, the KHorn is just a better sounding speaker in everyway IMO. Including the new gen which I don't like as much as the previous gen. It's not just the bass either, it has more air, does dynamics better and just pressurizes a room better. The midrange doesn't sound as congested either, especially compared to the AL5. I know it's not the same as in person but Paducah posted a video that gives one a broad strokes idea of that in their AK6 vs AL5 comparison video. You can hear how much mushier the midrange is vs the KHorn AK6. The sealed KHorn bass bin was something that was experimented with for 20-30 years and the only 2 production models where Klipsch did this prior to the AK6 was the 60th and 70th Anniversary KHorn. The Most recent anniversary model being the last of the AK5s made prior to the change to the AK6 design/driver changes. So PWK had definitely considered/experimented with a sealed KHorn bass bin for some time. Especially considering the fact that the underground Jubs he loved were front ported and sealed in the back using a KPT style bass horn. On the sealed KHorn they vent on the side but forwards at a 45 degree angle with a smaller exiting than the KPT bin. It acts as a further horn on the sealed back and really helps pressurize the room with fast, tight, clean bass. Makes integrating and finding an adequate sub that can keep up quite difficult. A fast sealed REL, Rythmik or Velodyne will do that ok other than a massive Danley tapped horn. And even though the bass bin is sealed, the Klipschorn is still very much a cornerhorn speaker. The sealed bin just gives one a bit of flexibility with toe in or when they have heating baseboards that stick out a 2-3 inches from the bottom wall that would be problematic on the open back model. So they still need to be at the very least in the vicinity of a corner, ideally no further than a 1ft or 2 off one. They can be placed in non-corners but the bass won't be nearly as authoritative and the bass bin may even draw attention to itself on deeper/harder hitting music/content depending on the room and other factors.

I don't think it's that. The new AL5 and AK6 are just voiced different. New tweeter, changes to the horn cabinet, new wiring etc. But the tweeter horn on them is specifically mentioned as Tractrix though where as the previous era was not in specs. The K-77Ds still essentially used the classic tried and true EV-35/Alnico tweeter horn. The New K771s the horn is different and on the new ones they are connected at the top of the mid horn and the front baffle of the tweeter horn sticks out a bit to the top of the mid horn. I'm no acoustic engineer but that change always struck me as an odd design choice. There are no blend issues between the tweeter and the midhorn on the AK5/LSII so the small gap between them wasn't noticeable as they were perfectly seamless when playing. Both were also matched phenolic diaphragm compression drivers where as the K771 uses different materials compared to the K55-X driver and specifically mentions the newly designed tweeter horn as well. Klipsch also definitely did some changes to the exponential K55-X midhorn as well. So the end result is a different sounding speaker. When you add it all up. IDK, if it's not broken, don't fix it. The LS II was a damn fine good speaker as was the K-77D tweeter. I would have just updated the new look to the LSII and put the new sealed bass horn cabinet on the KHorn and left them alone. IMHO of all the new models I think they did the best job on the Forte IV, both value for $ and sound. Porting the Heresy was also a mistake and makes using it as a center channel far more difficult as does placing near a wall in 2ch use more cumbersome due to the port. If you want more bass just add a sub. The Heresy was meant to be a sealed speaker. The Cornwall, Heresy, KHorn and LaScala all changed a lot compared to their previous generation pre-2018.

They would actually work pretty well in that room. My room is not too dissimilar but I have an opening further down, another foot or two and its just a small door sized opening, not opening into another room as the rest is essentially sealed. And also have a sofa on the side but its another 2-4ft down yours is a bit closer. Anyone in the middle part there would get good sound though watching general entertainment like TV. Now as others said with the toe in if they cross just in front of your main seating area you will a stable stereo image. In my case I have mine to cross just a foot or so behind my MLP because I get better point source imaging with movies so I send a little bit of L+R fill to my center Heresy and I get a better sweetspot for music than I would have for straight 2ch anyway. Bass wise, a sealed cabinet KHorn would work a bit better though, despite them sitting tight in both corners, reason being mostly the left side where the wall ends and opens to the other room and the KHorns with the open bass bins critically use the corner as an acoustic amplifier/extended horn to complete the bass bin. The sealed ones need corners as well but they have more flexibility for rooms like yours. Granted since it would sit snug though, active room correction or running stereo subwoofers and adjusting for the left side which may likely have a slightly weaker bass response will probably solve any issues that would cause. If the speakers are in very good cosmetic shape, and the drivers aren't blown or anything doing a brief test, if the price is right I'd buy 'em. You can always sell them if you don't like them.

I feel the same way about Crown class D, but tons of people use it. Each to their own but their lower powered amps are phenomenal. Depends on the sound one is into, what their usage is like and what music one listens to. A lot of tube amps and other SS, often have both far too high a noise floor and smothers detail and air for my liking. Old/Vintage McIntosh solid state (pre and amps) is especially terrible in my experience. Rolled off, mushy midrange, bloated, sluggish bass and way more hiss at idle than I could live with. Hi-Fi has come a long way since the 60s and 70s.

As others said it's the amp and/or it's gain setting if yours can be adjusted to lower. I'm not familiar with that model from Pass. I went through a lot of solid state amps, integrateds and surround pre-pro combos before I found the quietest, best sounding amp and digital front end. It had to be dead quiet at the MLP at the very least. It cost me a lot of money and 3-4 years of trial and error but loving the sound of heritage and being invested in my speakers I wanted to get the most from them and have them be completely inaudible hiss wise. I ended up with a noise floor where I can't hear any hiss at all from drivers unless you put your ear up against the tweeter on the grille on all my speakers. It's tough because some pre's are also far too noisy to be ideal for use with any high sensitivity horn as well. Some people don't mind it (vintage gear) especially if they can't hear it when playing but it personally bothers me and IMHO a great system should be technically sound from a noise standpoint and not only sound good when playing. LS and KHorn are very similar, although my drivers are the gen prior to yours and equivalent to the LS II, but same sensitivity. For 2ch, the quietest SS integrated I have used so far is the McIntosh MA5200 which sounded both incredible and was dead quiet. The Bryston 135 performs similar as I have heard the power amp section used in that amplifier in another Bryston product. Overall I got the quietest noise floor, sound quality and dynamics with Bryston amps. For Heritage all you need is their "2" series amps like the 2.5b. I briefly had a 4BSST2 (300W/ch into 8ohm) in my system in 2ch which was dead quiet as well although I sold it when I went converted my system to multi-ch for mixed use. Their vintage amps are nice too. Even the old 60w/ch 2B-LP Pros would sound great with a LS. Well engineered and designed Class AB I find has the best traits of Class A and Class D. If you are into more of a warmer, more laidback sound then you might be more into something like a Luxman. If you wanna try something cheap, the Schitt Vidar II is really nice and is 100w/ch into 8 ohms stereo. Very quiet.

~100W/ch Bryston Class AB and Heritage is an incredible combo. To date it's my favorite amp I have used for mixed movie/music listening at least in my main system. If you want that dead quiet background, lively, big dynamics with deep low end grip you honestly can't do better for the price. Far better value than McIntosh amps people buy for 2x the price. Pass Class A or Class AB is also an outstanding pairing but Bryston is also a better value for the buck there as well IMHO. There's a reason why Bryston amps are in major recording studios all over the world. Yes, high efficiency speakers can be driven with low watt amps, but not all watts are created equal and Bryston equipment runs DEAD quiet, this is critical for high sensitivity speakers. They don't cut corners, use very high quality power supplies and capacitors and their amps last forever. The 2.5 series or the 135 integrated you are looking at are the perfect amps for Heritage. Having all that current/power headroom does make a difference. I'd stay away from Crown class D anything unless it's being used for DSP/xover for a horn bass bin like in a underground Jub. For "normal" heritage, I found Crown sound to be shrill, harsh, sibilant and with underwhelming S/N and noise floor. My experience is with the newest XLS series.

I use a Vidar II on each of my Forte IV surrounds in bridged mono. They sound fantastic. Great tonal match for the Bryston I use for my other channels. Quick and tactile providing plenty of power for near full range surround reproduction. Schiit stuff is built really well and the quality/performance for the money is awfully hard to beat. They sound 100x better than the Crown XLS1002s I was temporarily running since the Bryston 2B-LPs I was using got burned out in a power surge. Need to get them both restored but I may just end up leaving the Vidar IIs in, I've been super happy with them. Had a Ragnorak as well about 6 years ago before I bought my current home or owned any Heritage speakers. That was a great amp as well. IMHO for Heritage Class AB is what you want if you like SS. Unless one likes more of a tubey sound then Class A is a bit more up your alley but Schitt doesn't make one and their AB amp isn't warm/laidback sounding. Class D just doesn't sound quite right at least in my experience on either the Heresy III or Forte IV. Never tried it on KHorns but have no interest, no matter how expensive or "high end" it is. For subs, class D is a different story though.

Amazing what Chorus IIs go for now a days. HiFi isn't an investment but Heritage is almost an exception to that rule. Just legendary and many owners own their speakers from new for decades. Very few other speakers/component brands like this. A guy is selling a NIB pair of Chorus IIs on eBay for 8 grand. Insane. Especially Considering what a nice used Forte III can be had for but also an indictment of how beloved the Chorus II is.

I only skimmed through this but honestly if you don't like the sound of the LS AL5s and/or they don't work well in your room you shouldn't force yourself to like them. One thing is genuinely liking something and its a another getting used to it or adapting to acceptance. When you make the kind of investment a pair of new AL5s cost you should be utmost satisfied, if you aren't especially after going through the many useful tips from some of the other members here, placement, electronic front end etc. than I would honestly return them especially since you seemed to be happy with the CW4s and enjoy those in your room. The room is a HUGE factor. Arguably the biggest for what speaker will work or won't. If the music isn't making you feel something either and you aren't getting into it or aren't being wowed by the sound at least once in awhile on amazing source material and all you can do is analyze/decide if you like what you are hearing then I'd get rid of them. Enjoy the CW4s or maybe try something like a JBL 4367 instead. Try a new SS integrated. Seems that some long time LS owners prefer the late model LS IIs and although I haven't heard them in person, the new AL5s appear to have a thicker midrange than can sound almost muffled at times combined with weak bass compared to the fuller response KHorn, CW and Fortes. I know I prefer the AK5 KHorn to the new AK6 model. Both in look and sound. The AK6 and AL5 have different drivers and crossovers with a new voicing. For 2ch the LS sounds best not too far away from a wall otherwise the bass in enemic. 1ft-2.5ft seems to work best on them. As others have said, you could have bad drivers for all you know. Generally though bad compression drivers are pretty easy to hear when they start to clip, distort, breakup, static pops etc. especially when amp/front end has been ruled out or they sound super rolled off. I will say as well that it took at least 500 hours of actual playtime before something like a new built LS or KHorn is truly broken in. The woofer loosens up and the compression drivers break in. They just do everything better. I personally don't subscribe to the trope of high efficiency horns, that you HAVE to use tube amps either. This is entirely dependent on the listeners sound signature preference and in large part what kind of music one likes. A nice mellow SET is all about the presence and immediacy with genres like Jazz or easy listening female vocals at modest volumes at best. You aren't gonna be able to blast some 80s new wave or some EDM banger on them, they will sound awful. SETs are more of a 1 trick pony amp with a very distinct sound and a seductive midrange for people that enjoy audiophile easy listening stuff most of the time. I honestly prefer my SS even for late night low volume Jazz sessions. Perhaps try some SS integrateds. Something like a Pass INT-60, McIntosh MA5300, Bryston B135³ or Accuphase E-380. Pass and Accuphase also have Class A integrated options as well. I can attest to all 4 of those brands sounding amazing with Heritage. The newer Mac amps no longer have that veiled, mushy sound anymore they sound 100x better than their old stuff. I ran the MA5200 with the KHorn for a couple years and it was the best integrated amp I had owned up to that point by a long shot. Heritage is very revealing with high quality amplification. Good luck and hope you truly find something that makes you happy with your system and sound. We've all been on that journey

Those are really nice. Fact you have the original documentation for them in such nice condition is also a great touch. Very neat depiction on them with a 3-channel stereo living room with a center Belle flanked by 2 cornerhorns. Like others have said these are cult classics and if you can find a way to hold on to them, I totally would. You might regret selling them someday! Best of luck!