Pete Fowler

Last update - LASE was out of stock (web store wasn't current). I have not found new/NOS K53 diaphragms anywhere. Fortunately one of the forum folk has parted with a used pair so I'm good to go. Cheers, Pete

Actually two things change when you swap in a K-28 (both good in my view)... As you guys mention the woofer will be 3dB louder (this helps compensate for the squawker-forward voicing of the stock Heresy's which is a good thing in my book), plus when you halve the speaker impedance from 8 to 4 ohms it effectively doubles the woofer's crossover freq from around 380Hz (in H2's with the later version xover) to 760Hz which would help fill the gap in the K53's low end that I mentioned before. Two - two tweaks in one! 🙂 That said there is more benefit using a K-42 or the Dayton than just power handling - they both have very strong magnets (much stronger than the K-28) which improves the motor control over the cone at high(er) freqs - which leads to better integration with the squawker. If you read Claude's thread on the Super Heresy's a few years back the primary reason he tried the swap was to improve the integration, not improve the bass. Thus a K-42 swap improves integration (speed and dynamics) plus bass to a greater degree than the K-28, but I think the K-28 would be huge bang for the buck if you're inclined. Just sayin'... Cheers, Pete

Interesting - I had the same experience while looking for a replacement diaphragm for my K-53. Automated first response, automated 'please be patient' email, then nothing. Perhaps they're backlogged and we'll hear in a few weeks?

Good point Randy - I guess it all depends on what a person is trying to accomplish. I was trying to duplicate the results Claude achieved with the K-42. Reviews made me think the K-28 still leaves the speaker overall bass-light (even ported in the H4). It also doesn't blend significantly better with the squawker (speed-wise). Big magnet drivers like the K-42 or the Dayton are a better match for the squawker dynamics although in the case of the Dayton some xover work is needed as mentioned above. When ported they also put out serious clean bass (which occasionally makes me giggle 🙂). As a drop-in upgrade the K-28 is much better and will give reliable results (although I think the H4 has some xover changes?). Either way it's a hoot to hear the results so a win-win no matter which approach.. Thanks, Pete

Hi Jd, Yes, dropped the cap and shrunk the inductor because despite the name the K53's '700' horn doesn't go anywhere near 700Hz. It's more like an 850Hz horn. So I ended up with a 1.2mH inductor crossing at 925Hz which blends really well with the K53K. I also had to add a zobel network for the woofer because the big voice coil has a ton of inductance and the rising impedance messed with the xover response. I was getting bleed through into the 4kHz range without it. Pretty interesting stuff once I figured out what was going on. 🙂 The final tweak was to extend the port length to 6" which is a nice compromise between extended low bass and a slight loss of detail in the 80-120Hz range. To my ears an acoustic bass sounds still sounds tight and right but you can really hear/feel the bottom end now. All in all a worthwhile upgrade. Cheers, Pete

A quick update as promised - I ordered from zxpc (LASE) on Dec. 17th - and...nuttin'. The order is still 'Processing'. Tried two emails and a phone call - no response. Since they're a small company I'm thinking the covid spike may have impacted them. I will give them another week... PeteF

Found one - thanks!

I've ordered two units from LASE - will update this thread once they arrive. I'm curious to compare my original set to these since the site doesn't claim they are OEM or Klipsch parts. Fortunately I still have one working original to use as a baseline. On a different topic - I've ported my H2's and replaced the K24's with Dayton PA310-8's (inspired by this thread - ) Would it be interesting to share the xover mods, etc. I needed to make those woofers work in the H2's? Thanks again to all! Pete

Thanks all - I had already checked Crites Speakers, etc. and no luck. However the link Randy provided has 2 available - I'll try my luck there. This community is the BEST! Pete

Thanks Randy - I just assumed they no longer made replacement parts for 35 year old speaks. D'oh! Request submitted...🙂 Best, PeteF

Thanks Madman - I'm hoping to find a replacement diaphragm but will keep these in mind! Pete

Hi All - I recently noticed the squawker in one of my H2's was down in output below 2kHz - turns out the voice coil DCR is up to 28ohms. It still plays but it's down 7-8dB. I can't find any source for a replacement. Any suggestions? Many thanks, Pete

One of my Heresy II squawkers dropped in output and when I measured the VC it was 28ohms. 😬 Still plays but down 7-8dB. Hoping to find a used replacement since all the new parts vendors are out of stock. I'll take one but if you have a pair I'm definitely interested (if they came from a pair of speakers with similar use/age/etc for better match). Many thanks! Pete

Been lurking for a while and I hope I can add something back to the community - I've recently installed/ported the Dayton PA310-8 in Heresys. The snag is I have Heresy 2's. Searching for more bottom end I replaced the K24's with Crites woofers and that made some improvement in bass but not enough (for my tastes/room). Recently swapped in PA310's and followed Claude's guidance on porting, etc. As predicted the mid/lower bass is both extended and more forceful while avoiding one-note/thumpy effects - it's clean and fast. The mids (esp. female vocals) are much better, too. The overall sound is good top to bottom. Well worth the effort for H2's. This is a pure guess but I think it may work the same in the H1's since you like their sound without porting. YMMV, etc. One caveat for stock H2's - the 2.5mH/68uf low pass filter sounds a bit thin in the lower male vocal range (for my tastes 😉) so I 'm thinking of trying a smaller cap to raise the freq up from 386Hz to maybe 430-450Hz. I'm holding off until the drivers run-in a bit more before I make the final call since it might open up the upper bass as the suspension loosens up. You probably won't have this issue with the H1 xover but just in case... Pete

Howdy, Sorry the table is hard to read - the forum SW compresses spaces...with the ports cut to 7" and the sides braced: -1 at 120 on up +3 at 50/60/80/100Hz +0 at 40Hz +6 at 31Hz +2 at 25Hz/20Hz Thermio only ran up to 200Hz because we use these cabs as bass bins below 180-160Hz with Oris horns. Can't answer your 300-150 hump question. The cabinet is on a side wall about 1.5 ft out from the wall, sitting on spikes with carpet over concrete. We used a CDP with a test tone CD and a RadioShack digital SPL meter. No room compensation, etc. included. Frode posted pics of his project in the thread below "...pictures anyone?". Ours look essentially identical. Now, all the data and facts aside - its sounds really good which is the real point of the mod, ya? Acoustic jazz, rock, vocals - you name it. Thermio is a really particular guy when it comes to clean, articulate bass... You might try building a pair - they're simple boxes and the K33E drivers are around $105 ea. Can't beat it...