Malcolm

Your experience is quite valid. It mostly comes down to phase of the sounds coming out of the woofer and squawker. If they are in proper phase relative to each other, everything works as expected. If not, you get unwanted interactions. The match is seldom perfect, but usually good enough. Sometimes an audible improvement can be made by simply swapping the connections on the woofer or squawker. When Klipsch made one of the many woofer changes in the Heresy they changed to a Type D Network. After doing some testing, Klipsch decided it sounded better with one pair of connections reversed. That resulted in the Type E Network and instructions for upgrading the Type D Network were published in a Dope from Hope issue.

Any one who has measured them or even run a simulation using Thiele Small parameters knows they begin to roll off a bit above 100Hz and are 3dB down by around 60Hz, as I said. Did you look at my avatar? I currently have 8 Heresys dating from mid 60s to early 80s. I got my first pair in 1972 and still have them. I have had others, including a pair of 84s I got rid of because of the difference in the midrange driver. You might try looking up the specs. The specs for the Heresy III give the frequency response as 58 to 20kHz +- 3dB, somewhat better than the earlier versions. In other words, the 3dB down point is around 60Hz. And so have I for many, many years. They are quite adequate for a lot of music. But as I said, there are some applications where you will need a sub, And if you need a sub, there is no reason to chase after extra bass out of the Heresys, at least in terms of frequency response. You aren't going to get much more in a sealed box design without losing efficiency or going to a different box design, but then they wouldn't be Heresys. You could use a woofer with higher Xmax so you could play louder down low before reaching the mechanical limit, or one with better power handling capability so you could play louder down low before you reached the thermal limits. But if you are running them in a typical home environment this isn't necessary. It is already hard to stay in any reasonble size room with them when they are cranked anywhere near their limit. There are lots of modifications that have been suggested on this site over the years. Whether they are improvements or not is in the ear of the listener. I have tried some of them. If you want my opinion, you will have to be more specific. The one modification I would suggest for Heresys with paper in oil capacitors is to replace them. I use metalized polypropylene capacitors. You might want to use something else. I won't go into detail about it because it has already been discussed thoroughly in other threads and this thread is about woofers with a sub. Yes and yes. And I even measured them before and after. Couldn't find a significant difference. Of course, I had to rely on memory. There is no way to A-B test the same speaker before and after a modification at the same time. And A-Bing two different speakers, one modified and one unmodified, won't yield reliable results because no two speakers are identical to start with.

Of course not. They have different box designs and volumes. Even with the same exact woofer they will sound different.

Now where did I put my copy of D1.1? I remember something about DBAs in there. At least that was better than some of the things I have heard DBAs called...

As long as you use a paper cone and maintain efficiency I think you would never be able to tell the difference. Klipsch used woofers from a number of manufacturers in the Heresy over they years, including EV, CTS, Eminence, Rola and others. They all sound the same. The timbre of the speaker is much more a factor of the tweeter and squawker, and the crossover frequency to the woofer, than the woofer. Likewise, I doubt impedance curves make an audible difference. Years ago I ran curves on several of the woofers used in the Heresy over the years. There were vast differences, yet they all sound pretty much the same.

You just did. Welcome aboard. The earliest Heresys were intended for use with a Klipschorn. Later models, were intended to stand alone. They had sufficient bass to reproduce most music of the day just fine, although not as well as the larger Heritgae models. The obsession we have with a** kicking base today is a relatively new phenomenon. FWIW best center for a Heresy system is another Heresy.

No.That is not what you said. Why would I think you meant other than what you said? The way you restated it, perhaps more so in a vague way. The way you originally stated it, no. In any case, Heresys require a subwoofer for many applications no matter what you do to them. And if you need a subwoofer, there is not much of a reason to chase a little extra base response out of them.

"Avid database programmer"? Hell, no! But I was a DBA once. What is the question?

Just a quick comment on reconing. Ideally, it is done with OEM parts. The problem with reconing Heresy woofers is that OEM parts are no longer available for many of them, like the SP12B. That doesn't mean they cannot be reconed. It just means that it will have to with generic parts. And if an appropriate generic voice coil is not available, it may mean having a voice coil custom wound. It can be done. It is just a question of how much you are willing to spend and if you are willing to use non-OEM parts.

EV cast frame woofers were used in the late 60s. Cast frame or stamped frame doesn't determine how well the woofer works. Klipsch used woofers from a lot of companies for the Heresy over the years. The decision at any point in time appears to have been driven primarily by availability and price. Despite the current fixation on Thiele Small paramenters by some folks, they all sound pretty much the same. The only technical improvements over the years seem to have been increased Xmax so you can play louder down low before reaching limits, and increased power handling capacity so you can play louder period. IMHO the best Heresy woofers are those based on the EV SP12B but I really cannot tell the difference in sound from the others. Yeah, but in this case you are unlikely to do better. The limiting factor on the low end is the size of the box, not the woofer.

No, they start rolling off a bit above 100 Hz and are about 3db down by 60 Hz. True, by today's standards. Options I would consider: See if Orange County Speakers can recone--unless you are lucky, it will be with generic recone parts, not OEM. See if you can find good replacemets on eBay, etc.--just be aware you can run into a variety of problems Get Bob Crites' replacements--no brainer if you are willing to spend the money Find new equivalents--not all that hard as there was nothing particularly special about the woofers Klipsch used, just pay attention to sensitivity. Price might be a bit less than BC's depending on what you choose.

I have five Heresys and a sub. Makes a great HT system. Don't hold your breath for a matching center.

So? In any large company you are going to have some employees doing the same.

At least some laptops have one or more fuses, if not all of them. Look for a surface mount fuse on the board. Looks like a little brick soldered to the board. The legend on the board will likely have a number preceded by the letter F. What you won't likely find is a tubular glass fuse in a clip. Replacement is something better left to a pro if you don't have the experience.

That calculator assumes that you are OK if loss is 1dB or less, which may or may not be true. I prefer a table produced years ago based on listening tests.

They look perfectly appropriate for the last of the Heresys. No need to upgrade the crossovers. The main reason people do it on older Heresys is they have paper in oil capacitors which deteriorate with age. Yours have film capacitors, which seldom need replacement.

Actually, I wasn't suggesting anything. I am just tying to follow your logic in doing something at odds with most manufacturers of surge protectors. Of course 250V MOVs are fine in a 130V circuit. But you wind up with a much higher clamping voltage. Surges below 600V or so are not an issue for you? FWIW it sounds like you live in one hell of a neighborhood, electrically, that is. I read somewhere that most MOV failures are not due to surges, but sustained over-voltage situations. Using a higher voltage rating would help with that.

Perhaps in some some cases, usually not. Depends on where the varistor voltage of the part falls in the distribution. OK, so why not use a 140V part, or something else in between that and 250V? Seems like using a 250V part is much more conservative than necessary from the standpoint of reliability, and pushing your luck as far as protection goes. The MOVs in my whole-house surge protector are 150V parts and have lasted 10 years. Of course, they are 40mm parts, not 20mm parts like in your strips.

Well, they certainly shouldn't fail now. Any reason you are using S20K250's? Those are 250V parts. The originals are likely 130V parts. Maximum clamping voltage is something like 650V v. 170V. FWIW paralleling MOVs doesn't necessarily resultant in a corresponding increase in the surge current the device can handle. The MOVs have to be closely matched to do that. If not, it is possible that a single MOV will handle most or all of the current. MOV manufacturers offer closely match MOVs, but it is special order. The S20K250 is plus or minus 10% which might be problematic. Paralleling MOVs does provide redundancy, though. If one fails, there are still others to do the job.

Well, once the glue joints fail, the correct way to fix the problem is to disassemble, remove the old glue, and re-glue. The reason the top only comes apart a few inches down the sides is probably that they are nailed. Assuming that you don't want to completely disassemble, just glue with carpenters glue and clamp. It won't make any difference if you inject the glue from the inside or the outside because it will squeeze out on both sides. Clean up squeeze out with a damp sponge. You can tape the finished sides right up to the edge to make it easier if you want.

Follow the manufacturer's instructions...

WTF did you remove the motorboard? Horn is aluminum, not steel. If you are sanding by hand, wrap the sandpaper around a block of wood or your will likely wind up with a wavy surface.

How can you tell without a serial number? Type C network arrived with the K700 horn and a 700 Hz crossover point between woofer and squawker. OP's Heresy has a K1000 horn and the appropriate crossover to go with it.

It is usually best to stick to the same line. Speakers from the same line are timbre matched.

Keep the internal volume the same and omit the ports and there should be no problem.