Heresy Project

[EJC1]

Roughly 5yrs ago I updated/Upgraded Forte IIs with the Crites Magic Parts. The results were magnificent and I suspect that the speakers will be good for another 30yrs.

At another location, I was not happy with the sound of the current system: Yamaha RX-A860, M-L Edge in-wall (R&L), M-L SLM surface mount (Center) and Parts Expres (Sub). The high ceilings in the room appear to be the major problem. I decided I would try floor standing speakers. I also have to keep "She who must be obeyed" happy. I decided that another pair of Fortes would be too big and the Heresys would fill the bill. I also decided that since I was happy with the Forte rework that I would start with a blank cabinet and use all Crites parts.

Some (Klipsch Forum) have said my budget set at $1500 was too high as speakers could be picked up for $400-$500. I know myself too well to think that I would leave a used speaker alone without modification. I instead was comparing my cost to a new pair at $2000 (Amazon)-$3000 (Crutchfield), in which case the rebuild would be a bargain.

So, the project is on. I've got the parts and the cabinets should be here Weds. I put a similar post looking for ideas on the Klipsch Forum.
The cabinets are Heresy I HBR from '79 and a previous owner finished them.
The drivers and x-over are all Crites updated parts.
5-way binding posts will replace the original barrier strip.
Damping material added to the driver frames.
Gasket material will be added to the front and back boards.
And the speakers will be on risers, my thinking is this is a must because of the high ceilings

Now the questions:

1- I've read of some have added bracing to the interior of the cabinet, is there any real benefit to this added rigidity?
2- Some have added fill to the cabinet, not sure of the benefit and won't it decrease the volume of the sealed cabinet affecting response?

any and all ideas will be appreciated

 

[moewillis]

cool project. i cant wait to see the results

 

[moray james]

the benefit to adding cabinet brace work is reducing the noise made by the cabinets walls when they flex. If you add the appropriate damping material for the intended frequency band the woofer will respond as if it was in a larger cabinet volume not a smaller one and you will pick up some additional bass response (extension). I have included a link to a thread I started here showing how I used 3/4" white oak to brace two sets of H3 cabinets. It is hard to see but all the cabinet inside edges have a full length of oak strapping to seal and stiffen the panel joints which are especially poor on the H3 front and rear baffles. The front baffle has cross bracing between the woofer and the mid horn. Sides top and back have two sets of bracing all the grace work interconnects into a sort of matrix resulting in a very rigid cabinet. Cabinets are over 90% solid stuffed with high density fiberglass. There is a small open air gap about 2" thick between the woofer and the damping. Damping material is on edge to the woofer and this is critical to achieve low frequency absorption of energy placed at right angles the damping is not effective at low frequencies. This is because the damping material is pressed and the sides of the damping panel sheets are much more dense (hard) and reflective that way they are far less absorbent. It takes a lot of modification work to get decent bass out of a Heresy brace work and damping are just the beginning.
I think that for the time and money a used set of H3 with their much better network design and ti diaphragms in both mid and tweeter horns is a far better way to go so far as performance goes compared to updating an H2 or a Heresy. Voicing the speaker becomes the difficult part of the job and even the H3 with its networks designed for the ti diaphragms still requires a lot of work to get the balance right. moray james.

http://audiokarma.org/forums/index.php?threads/heresy-3-brace-work.438234/#post-6652105

 

[EJC1]

Thanks for the pics Moray. I'll see what I things look like when the cabinet gets here.

 

[EJC1]

The last of the parts for the Heresys arrived today and everything went together smoothly.

The cabinets were in great shape. they had been stained nicely, looked great and no blemishes.

All parts were supplied by Bob Crites. All of the parts were the upgraded parts.

E X-over

Woofer - CW-1228

Sqwaker - A-55G with original K-700 horn

Tweeter - CT-120

5 way binding posts replaced the original barrier strips.

Gasket material added to the rear panel for a better seal.

I added damping material to the driver frames.

I did not damp the cabinet walls and I decided not to add bracing to the cabinet

The project came in on budget at just under $1500 for the pair. Some felt this was high, but since I wanted to do a complete rebuild i felt it was quite a bit cheaper than new.

I could have bought complete speakers for less, but knowing me I would have ripped into them and replaced parts anyway. And would the cabinets have been as nice?

Finally, the sound is great. Didn't listen for too long but so far, loving them

 

[longdrive03]

Great project.

 

[longdrive03]

How do you like A55 mid driver?

 

[EJC1]

How do you like A55 mid driver?

Frankly, I think the sound is magnificent. The project finished better than expected and the wife is happy as they are not too obtrusive in "her" living room.
They are in a system with a SubW so there is no complaint on the bass and they solved the problem I was having with the ML in walls, which I now consider an expensive mistake.
Here are the 2 videos I did on the project:
The Build:

The System:

 

[EJC1]

The speakers now have another 40yrs to go!