Klipsch Heresy Speakers Circa 1976 ...Type HDBR

Let me be more clear:  Do I need to rebuild the CROSSOVERS ?

No! If they sound good to you leave them alone! I have a pair just like yours (raw birch) - and they sound just fine! I bought mine for use with my SET 45 and 2A3 amps. With 100db sensitivity the Heresy is a good match for low power amps.

Should you need to rebuilt or want to upgrade you should check out Crites.... they have all sorts of upgrades for Klipsch speakers.....   I love my Heresys.... rock on....

I have a pair of 76 JBL Century's I bought new and they sound better than the day I bought them.  And they have been driven hard.  The first 30 years by a Pioneer SA-9900.  

I also have a vintage pair of heresies that I love, they sounded good when I found them but I rebuilt the crossovers just to see what it would do.  The process is very easy, the crossover could not be easier to access and work on and in my opinion is a very worthwhile upgrade.  I love horns, but they can cause headaches if not done properly... getting everything back to spec seems to have made a huge difference in this regard.  What matters most is what makes you happy, but for 20 minutes of work (and a small investment) you can take them to where they were intended to go.  Add a sub, and congratulations.

I asked my self the same question long time ago (about 17 years ago) when I read somewhere that the crossover of my 1891 HBR is only good for 20 years or so. The majority response I got was “trust your ears.”  If it sounds good to you, leave it alone.  I did. 
Either I got lucky on the crossover or I’m deaf. 

I also have a pair of Heresy I's birch raw that I had the crossovers recapped/rebuilt.   When I brought them home, I noticed one of the tweeters was not operating so I went on Bob Crites website to order a pair of his CT-125 replacement tweeters and due to the age of these babies and the rear panels were coming off anyway, I opted to also order his crossover rebuild kit.  Performed the work and they were as good as new.

My "newer" Heresy II's have not been recapped and most likely won't be unless I detect an audible reason to have them refreshed.

Enjoy your HI's and don't mess with them until you have to.
Maybe someone else has already performed the work.

Bill

   The last pair of Heresy’s I had were 73’s and used the type C crossover with the 16ohm woofers. I tested the stock cans after I pulled them, both the 1 and 2uf cans tested perfect, I replaced them with Solens anyway but did keep them. I had a pair of 81’s that used the type E crossovers, one of those cans was off at 3uf high. 
   I have read that it’s possible a capacitor may test well but not perform well sonically. As previously posted recapping yours is about as easy as it gets and even if you opt for some medium to higher end caps this will be relatively inexpensive. 
   I just placed an order to recap some type B’s for the Cornwall’s. The crossovers are in about as good a shape as they can be with all the cans testing perfect. I’m going back with Mundorf Supremes, Evo oils, and Vishay .01 bypass caps. I’m doing this just to see if it’s a holy crap I wet my paints that sounds so much better moment, or wow that was a waste of time. Actually a set of stock crossovers, a set recapped with Soniccaps, and a set recapped with Mundorfs and bipass caps will be compaired. Depending on the results I may throw in an Audyn, Jatzen, or Dayton capped set. 
  If your curious recap one set and do a comparison. You can also dynomat the horns, add some dampening, and seal up both the baffle and the back of the cabs. Turn your woofer 180 degrees to counter any voice coil sag while your in there. 

Rewire it,and rebuild the entire Xover with quality parts 
I had the exact same speaker. The interior Xover uses 
Still till this day No name parts that are not Audiophile 
Even electrolytic used in  the signal path. In this day and age 
Spend $6-800 you will transform the speaker 
Bob Crites can help ,even upgrade the woofers.

Dampen the mid horns ( from the rear ), as this makes a substantial improvement throughout the entire speaker. Look up " horn dampening in speakers ".