Tizman

Hi All. I picked up a pair 1976 La Scalas about a month ago and really, really like them. I got to thinking that I would like to build a diy set in two parts, separating the bottoms from the tops, and build them out of one inch Baltic birch plywood. My question is in regard to the ramps that create the horn shape from the hole in the woofer's motor board to the left and right back corners of the cabinet. Could these ramps end at the front of the flat parts of the doghouse that are parallel to the cabinet side instead? Would this result in a better horn that has a progressively increasing mouth size as opposed to a horn that has an increasing mouth size in the back where the ramps create it and in the front where the sloped doghouse and the cabinet sides create it, but a section in the middle that is not increasing at all? Please see the attached drawing, a very rough one, as it helps explain what I am talking about a bit better.

Thanks for the spec sheet. I tried moving the speakers around and found that it is much less of a problem when the speakers are elevated. Both the Tangents and the Quartets sound better when they are a foot or more off the ground in my room. The vocals sound cleaner and imaging is better. The Heresy ii were always elevated so that I looked right at the tweeter when listening. Anyway, now the best sounding set is dependant on the music I'm playing. I like the modified Tangent 500 better than the Quartet now. It's very much a Heresy ii with more bass. Next is the mods on the Heresy ii. I am going to install Crites titanium diaphragms, switch the small value capacitors in the crossover to Russian K75-10, and replace the electrolytic with a 68uf mkp film cap. The caps in the Heresy ii appear to be original, so they are 31 years old. I must say though that every capacitor that I have switched out of a Klipsch speaker has been bang on with respect to specs. Nothing fancy, but on spec. Even the electrolytics. In fact, I had bought a pair of non polar electrolytics to replace the ones in the Tangents, but the ones in there already measured closer to 68uf than the ones I bought, which were both close to 80uf each! I left them in and bypassed them with a 1uf film cap. Thanks for all the responses and advice!

Hi. Also, would anyone happen to know the crossover frequencies for the Heresy ii crossover? I have been searching, and the schematics are available but not the actual crossover frequencies.

Thanks for the quick replies and hi Geoff! The crossovers in the Heresy ii and the Tangent 500 are the same, and the drivers are the same. I guess the interaction between drivers and cabinet varies the impedance, which then varies the response? I will try a SS amp, to see what happens, but I'm probably not going back in that direction at this point, so a tube friendly solution would be preferable. At any rate, the inductors for the woofers are 2.5mH. What would be a value that might fix the problem? I can probably look it up and sort it out myself, but crossover modding is relatively new to me, so if anyone has a suggestion I would appreciate it. I have a couple of unused 6mH inductors here, as well as some magnet wire, so I can unwrap or add some wire to either the 2.5 or the 6mH to get it where it will sound better. Thanks again for the responses, and for any advice you may have.

Hi all! This is my first thread here. It's been great being able to have access to all the information and expertise contained in the community. Thanks to all the members who I have learned from. I am the proud owner of three pairs of Klipsch speakers. Quartets, earlier Heresy ii and Tangent 500. The Quartets and Tangent 500s have upgraded crossover capacitors. The Quartets have Crites titanium tweeter diaphragms. The Tangent 500s have had their cabs extensively braced and dampened so that they are very quiet and well damped. The Heresy ii are stock. I find that the Heresy ii are my favourite. This is because the other two pairs both have an odd thickness to vocals, especially female vocals, that makes them sound as though there is an emphasis on the deeper notes of all vocals. It's a subtle, but noticeable emphasis on the lower midrange that sounds unnatural and is distracting. Crossover upgrades were done with higher quality caps of the same values, and they had this problem before and after the cap upgrades. I'm wondering if this is something that anyone else has noticed, and if there is anything that I can change in the crossover or elsewhere that might solve this issue. I use mostly my own DIY single ended tube amps to power the speakers. Any advice of recommendations would be appreciated.