DirtyErnie

MN Athiest society are pretty big sponsors of the St. Paul Saints, so that kinda explains some of that.

Just because the computer thinks the woofers are able to dig 10Hz deeper, I wouldn't recommend going down there with crossovers if you can help it. Glad you're enjoying the new hardware! If you get bored, pop one of the old plastic diaphragms into one tweeter and compare with the new titanium one. The difference won't be as subtle as you've said.

Bingo. Wow, this is an old thread, didn't realize that. I'd say the OP's problem was related to this: RB-41 Specs Lower cutoff on those is at 85hz, I wouldn't send them high-level signal below 100Hz. Crossing them over below even 80hz, which I think was mentioned, would unload the drivers and suck down massive current levels. I had this happen to me with a bass guitar cabinet, an old Kustom 4x12 with a pair of ports. (well, it was just a shell, we made a new back panel and my guitarist/patron put some cheap 12" subs in it). First few gigs as it stood, I was getting no bottom end and flashing the 'protect' lights on a 1,000w bass amp (700w into 8 ohms). Then I kludged some homebrew ports out of construction paper and duct tape. 8 1/2" ports lowered the cabinet frequency enough to keep the drivers loaded, suddenly I had bottom and never flashed the protect lights again. So, even if it's an anecdote, Word to the Wise: NEVER FEED PORTED CABINETS FREQUENCIES BELOW THEIR TUNING!! (Unless you like to smoke voice coils and/or hear them smacking into the stops)

We would all like to think that, but it's extremely rare. Only a sealed box of the proper size is capable of doing that for a passive speaker. You could add high-pass capacitors before the speaker, but that can mess with other things. The reliable way is to multi-amp your setup and only feed a driver with the frequencies it can produce. Expanding on this: Ported enclosures UNLOAD the driver below their tuning frequency, and the farther below that frequency you go, the less power it takes to drive your woofer past it's mechanical limits. Sadly, and especially with cheaper boxes, that tuning frequency can be a lot higher than expected.

Similar with my CF2's. placed parallel, firing out into the room, the sweet spot was lock-your-head-in-a-vice tiny. Then I crossed them over so both speaker's coverage pattern was covering all the seating positions. It's pretty even and nice in there now. They almost look silly, and are crossed waaay in front of the seating position. Sounds nice, though. Best balance is still right in the center of the main sofa, but it's much more even off to the sides.

I did my KG 2.5's with Bob Crites' kit, substituting Erse PulseX for the high-value electrolytics to have all film caps in the crossovers. Did it one speaker at a time in stages, first step on one speaker, second step + first step on other speaker, third + second on first speaker, et.c... and listened to both speakers playing familiar music before moving on to the next stage, it was an eye-opener. Step: Replaced both electrolytics with the Erse film caps. Treble on that speaker opened up and became very clean and balanced. I was not expecting this, as both electrolytics were on the low-pass side of the crossovers. Maybe the 'shunt to ground' of high frequencies wasn't happening for the woofers, and all that energy made a mess of things... Replaced the film caps, 'full recap'. Vs Step 1, treble expanded and cleared up. The KG's would have been very listenable at this point but... Replaced stock tweeter diaphragms with Titanium. Treble cleaned up even more and became very extended and smooth. I'm using one of the 2.5's as a center channel speaker with my current CF2's. There's a very good 'family resemblance' between all the speakers, although the 2.5's definitely don't have the same sort of 'horn THAAAANG' that the Epics have. Also, I want more horns. Every step along the way was NOT subtle, it was smack-you-in-the-face obvious that something had been improved each time I did something. Maybe I should have taken the time and tried the new electrolytics from Bob's kit, just to see, but I kinda new where I was going to end up and just went for it. If you're curious about it, just get some components and go for it. It's pretty easy to put the original stuff back in if you're not satisfied and know which end of a soldering iron to hold.

Is there any way you can post before/after/EQ curves for the 2.5's? I never really thought mine needed much help, in a 13' wide living room with 8' ceilings (room length? there's four different ones, between the closet, bathroom wall, hallway, and bedroom wall sections). They definitely needed a subwoofer crossed at 50Hz to support the lowest frequencies.

I'm a big fan of subs if they're properly blended with the mains. no frequency overlap, no level difference. Also my preference is to cross to the mains a bit above their lowest frequency, I'm not really a fan of 'port' bass if the sub sounds better/quicker in that frequency range. I should add to this, there's often little energy in most music below 35-40Hz, most people are surprised to learn that the 'thump' of a kick drum is at about 80Hz, where the average human chest cavity resonates. About the only recording I know of that can get below that is 'Dare' by Gorillaz. There's a sub-harmonic in the ~20Hz range that you'll miss once you've heard it. (and I have 4 12's that need to get built into a floor joist infinite baffle....)

If you don't get it, stop thinking about voltage and start thinking about current. Voltage doesn't make magnetic fields, current does. Magnetic fields cause cross-talk and modulation distortion. Stop the frequencies, stop the magnetic fields, stop the modulation distortion. Now your cables don't have to be full-range (think Lowther), with all the quality demands that requires.

I'll second what wuzzer said. I did a staged/stepped upgrade on my 2.5's, one speaker at a time, one change at a time. Did one thing, listened, took other speaker, did that thing and the next thing to it, and so on. swapped out the electrolytics for ERSE PulseX, sound cleaned up greatly and all the treble came from the modified speaker. Oddly, both of those caps were on the woofers. Swapped in the film caps from Crite's kit (don't remember the style). Even better treble and sound. Added in the titanium diaphragms. The highs extended and became beautiful. There's not really much else to say about it. I'm using one of the 2.5's as a center channel speaker, with my CF2's. Tonal balance across all three speakers is pretty good, not a huge surprise since the CF2's have a light metal diaphragm in the horns. Highly recommended upgrade.

Golden Ratio?

It's too bad these kids didn't get to live through the 80's and see just how horrible all that junk looked then, and how bad the recreations are now. Then again, my generation did all that in the 90's, but with the 60's. But the 60's had Jimi and the Saturn V rocket... 80's had cocaine and the Challenger disaster...

I like this page: Capacitors at the Crossover Design Cookbook, cross-referenced with this: KG x.2 Family which says a 5.2 has a 1,600 Hz crossover point. There's a graph there that shows impedance -vs- frequency of a given capacitor value. If we're assuming that's an 8-ohm tweeter, we get these values (assuming the frequency break-point is where the capacitor impedance crosses the 8-ohm line) 2.5uf = ~8KHz 8uf = ~2.5KHz and the inductor + Resistor here Inductors at the Crossover Design Cookbook: 1mH + 4ohms = either 630 hz or ~1,800. I'm going to choose the lower value. Either way, the inductor's break-point is below that of either of the capacitors. My thought about doing an impedance trap was to swap the positions of the 8uf and the 2.5uf, and put the trap between the inductor and the second capacitor. this way, you wouldn't need to add the additional capacitor, and you haven't changed your frequency break-points. By the inductor chart linked above, you'd be looking at a .15mH inductor and an 8 or 10 ohm resistor to trap down the impedance rise of the 2.5uf cap. Try that set-up in xsim and see what impedance you get vs. the stock crossover.

Maynard, I'll agree, triodes do have a pretty wide range of reflected impedance that they can deal with, but a 4x impedance jump through one crossover band or another is definitely not a happy thing for a load line. Some amps are more tolerant of this than others, and the infinite number of amplifier /speaker combinations out there, every one becomes a rule unto itself. So, really, who knows what the issue is in mmuetst's situation. But, I know where I'd put my money. If I wasn't planning to go biamp/active at some point, I'd put more effort into mine. What a fun hobby, eh?

I'm pretty sure it's possible to re-design the crossover to provide both the rising response and the flat impedance, but the order of the capacitors needs to be reversed, and a series resistor-inductor would have to be added to balance the load properly. I've not really had time to dig into it, beyond some basic proof-of-concept stuff in a crossover design simulator who's name escapes me right now... XSim?

KG 5.2 has the Tractrix horn. Tractrix horn is a 'constant directivity' style, requires a 6dB/Octave rising slope for the horn to make accurate treble response, otherwise it would sound like the high frequencies are rolled off. Klipsch crossover is probably set up to use the horn's natural high efficiency to provide this rising frequency response, by setting one of the crossover frequency points well above the actual crossover frequency. I own a set of CF2's, the crossover high-pass are set for 2.5 KHz, but the first crossover capacitor is a 1.75uf, setting the crossover frequency at about 15KHz, and rolling off 6dB/octave below that point. This set-up does give a 2.5KHz crossover, but with a 6dB/Octave rising frequency slope up to the high treble, which is what the horn needs. BUT, this arrangement also causes a very large spike in impedance (up to 20+ ohms) from about 4KHz to about 10KHz, and your tube amplifier does NOT like that. If I was a betting man, that arrangement is where I'd put my money as far as what's causing your issues. The solid-state amps are much less bothered by this impedance spike, and therefore sound better.

"There are two entities on this earth that can make a couple hundred-thousand adults jump up simultaneously and scream "JESUS CHRIST!!" at the top of their lungs: The first is the Billy Graham Crusades, The second is the Minnesota Vikings."

Go with whatever is closest to the source format, nothing screws up a good stereo mix like your receiver interpolating a third or fifth speaker that's not on the disk.

Got a description of those cabinets, or a build thread?

Got a look under them again. There's rubber caps over some metal feet with a 1/4"-20 thread up the middle. OK, time to get some spikes. I like @moray james's idea of the ramset spikes, but really don't feel like picking up a box of 200 to do it. Then again, some goober on eBay is selling that exact thing in a set of 8, with stop-nuts, for the price of the 200-pack. What a world...

Maybe I'll try to unscrew them one day. Didn't pay much attention inside the cabinets when I was bracing.

BTW, my CF2 won't accept spikes, the feet are just hard rubber nubs. Nice score on those CF3!

Looking at a 3rd order crossover, there is a Series element, shunt element, and another series element. In the high-pass section, that's a series capacitor, a shunt inductor, and another series capacitor. As I under stand it, these three elements are each adding 6db to the slope of the crossover, and the shunt element should be between the two series elements. Typically, the series elements are of different values, moving their respective break-points to slightly different frequencies depending on they type of x-over you're after (L-W, Butterworth, whatever) This leaves the question: Does it matter which order the series elements (capacitors specifically) appear in the circuit? Are there specific engineering reasons for typically putting the smaller capacitor first and the larger one second? Could the order be reversed without significant change to the behavior of the circuit? Thanks!

Did a cap job on one, haven't done the other yet, checking up on the difference. My Sony receiver might be more responsible than anything, but still sounds good and has the automatic EQ function with it's cheesy calibration microphone. Only thing I don't really like is the horn is noticeably louder than the 8" woofers. Not sure if an L-pad or manipulating the crossover CD slope is the right trick, but the Sony does handle that for now.