Al Klappenberger Posted January 8, 2003 Share Posted January 8, 2003 Qman, The difference you hear in the bass with my network is becasue of the air-wound woofer inductor (the big 2.4 mHy job). The iron-core inductors Klipsch uses are not as good. They actually change inductance dynamically at each instant along the waveform. I think that's the reason but I really can't be sure. Al K. Quote Link to comment Share on other sites More sharing options...
Q-Man Posted January 8, 2003 Author Share Posted January 8, 2003 The frequency test conferms what I didn't like while listening to music the last couple of days. The 288/805 doesn't like the AKL network. I had more consistent readings when I had it hooked up to the AK-2 a couple of months ago. It's too weak between 315 to 630Hz. I may have to use it with my AK-2 and AK-3 networks. Darn I liked what the ALK was doing to the bass end. I need to talk to Al, I think he once told me that he couldn't modify his network. Maybe he can design me one. Again, I now need to try the Altec network, and then the AK-2 again. Worst case I'll have to use the AK-2 it didn't sound bad. These four drivers and horns could always go to ebay. Altec does have 804-B 400 Hz. horns and a driver that goes down to 300Hz.called the 290. Tom,I'll look into an active crossover, and ask you a couple more questions about making the one you mentioned. Stock K-Horn AK-2 K-Horn W/ 288/ALK 250Hz. 88db 90db 315 92 88 400 92 84 500 88 80 630 89 84 800 90 89 1kHz. 88 92 1.25 88 91 1.6 88 90 2 87 91 2.5 87 92 3.15 86 91 4 87 90 5 90 91 6.3 94 94 8 90 89 Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted January 9, 2003 Share Posted January 9, 2003 Q, My limited imagination can't figure a thing from those lists of numbers. I need to see a plot! I suspect that what you might have there is a crossover "glitch" though. Try inverting the polarity to the squawker driver and reseting the transformer taps. The netwrok shouldn't care what driver it's operating into. Point to point tests with a single sine wave and a sound level meter will lie to you also. All you need to do is take a step to one side hjolding the meter and the reading will change drastically. You need pink noise bands or warble tones. AL K. Quote Link to comment Share on other sites More sharing options...
TBrennan Posted January 9, 2003 Share Posted January 9, 2003 Klappenberger says "The netwrok (sic) shouldn't care what driver it's operating into." What, do you know the impedence of the 288 at 400hz? Is it the same as that of the Klipsch driver? Quote Link to comment Share on other sites More sharing options...
justin_tx_16 Posted January 9, 2003 Share Posted January 9, 2003 Q-Man. You make me ILL! Share the fun hehe. Quite impressive. Quote Link to comment Share on other sites More sharing options...
erikjohn Posted January 10, 2003 Share Posted January 10, 2003 Q, Looks like the project is coming along nicely. Your doing a sweet job on those cabinets. I will have to swing by so I can check it out. Maybe I can stop by next week sometime. It looks like you have rearranged things a little since I was over last time. Do you think you will have that power conditioner by next week? I would like to hear what kind of difference it will make. It looks like the AK-2 are a decent network judging by those numbers you posted, it's pretty flat. I like the way they sound in my Khorns. Hey do you think you could burn me a copy of that test tone disk you have? EJ Quote Link to comment Share on other sites More sharing options...
Q-Man Posted January 10, 2003 Author Share Posted January 10, 2003 Al,Tom,and EJ, I'll keep trying, and posting. I didn't have time to play last night. Al, I'm using warble tones, and I know what you mean about moving the sound level meter. Just moving it a few inches makes a difference. I have it on a tripod centered between the two speakers. Tom, I down loaded a manual for a Rane active crossover. These are connected between a mixer or pre-amp and then on to separate power amps for the drivers. They use 1/4" ,and, or 3 pin balanced connectors. I think your telling me that I can use one like a passive crossover, between a power amp and the drivers. Is this correct? EJ, I received the PS Audio 4.7 Power Director last night. I have it hooked up in the home theater room. I only listened to it a few minutes, just to make sure everything was woorking. I may be hearing a slight improvement. I think the 30 Amp dedicated circuit that I put in also helped. I'll need to listen over and over to something and then plug directly into the wall and listen again to be sure. I'll make you copies of the test CD, after all you make me those Blues CD's that I'm enjoying. I'll say one more thing, I do want to use this 288/805. The sound is fantastic. I just have to get it right some how. Someone once said that they could feel the spit coming from the horn while listening to a sax. Like I said I'll keep trying and posting and asking for opinions and help. EJ, just let me know when you want to come over. Now that I raised the shelf over the false corners, the Jenson Imperial will also fit under it. My son wants to do an A/B with the Klipschorn. Would you like to be there for that? Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted January 10, 2003 Share Posted January 10, 2003 Q, Only one small point. You should have the sound level meter about 3 feet in front of JUST ONE SPEAKER and run a signal only to it. To put the meter between two is a mistake. You are measuring your room when you do that. You need to measure the near-fieled to get a good idea of what a speaker is doing. Brennan, As usual, you don't know what you are talking about. Stick to "JBL/ Altec historian", that's all you know. Now go away! Al K. Quote Link to comment Share on other sites More sharing options...
Q-Man Posted January 10, 2003 Author Share Posted January 10, 2003 Al, I'll set it up that way tonight and try it before I start trying other networks. I'll also try another 288 driver and see if they measure the same. Quote Link to comment Share on other sites More sharing options...
TBrennan Posted January 10, 2003 Share Posted January 10, 2003 Al---You should know that the crossover is effected by the actual impedence at the crossver point and not the nominal driver impedence. I mean you know that right? So if you claim your network works with the Altec 288-K then you've measured the 288's impedence at 400hz right? Otherwise you really can't know how well it will work can you. Bluster all you want, are these facts or not? So what's the 288-Ks impedence at 400hz? What's it's impedence on the 805 horn? Is it the same as the Klipsch driver on the K-400? Don't tell me you don't even know the Klipsch driver's impedence? Quote Link to comment Share on other sites More sharing options...
TBrennan Posted January 10, 2003 Share Posted January 10, 2003 Q-man---An active crossover goes between the preamp and the amps. It's like this: lets say you're crossing at 500hz. The signal goes from the preamp to the active crossover. From the crossover the signal above 500hz goes to one amp which amplifies the signal from 500hz up, this amp is connected directly to the treble driver. The signal from 500hz down goes to another amplifier which amplifies the signal below 500hz. This amp is connected directly to the bass driver terminals. Passive crossovers are thus avoided. Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted January 10, 2003 Share Posted January 10, 2003 Qman, Now that Brennan has stuck his nose in this thing, I am going to have to explain it. Qman, for you, I will do it! Most crossover network filters are critical to what load you put on them. The filters in my network are no exception, however. My design uses a 10 Ohm swamping resistor across the autoformer winding. The filters are designed for 8 Ohms. The normal tolerance in load impedance for most filters, including those used at microwave frequencies is 1.5:1. That is often expressed as 1.5:1 VSWR. Therefore even with NO DRIVER AT ALL connected to the squawker terminals of my network, the load seen by the filter is no higher then 10 Ohms. That represents a mismatch of 8/10 or 1.25:1. This is within tolerance. It also happens that most high quality drivers have efficiency ratings (NOT sensitivity) that are nearly equal. Power input is a function of current times voltage. Note that impedance level is NOT part of the equation. It does not matter what the Zo of the driver is so long as it is roughly equal to the K55 in efficiency. The impedance will transform back (through the autoformer) to what the network was designed to see by itself when you move the taps to get a similar level from any given squawker. What little error is left is "swamped" away by the 10 Ohm resistor. This swamping resistor is also why the output taps can be changed on my network. Moving the taps has a far greater effect on the impedance reflected through the transformer than changing from a 16 Ohm to and 8 Ohm driver would have. So I say again: The network does not care what driver you connect to it! Brennan, GO AWAY! There IS a factor that should be considered here though. My network is a higher order filter than the AK-2 network and has a different insertion phase at the crossover frequency. That is why my network has inverted polarity compared to the Klipsch "AA", for example. This means that the polarity of the squawker relative to the woofer may need to be changed. If it is wrong, you will get a dip right at the crossover. The best way to set it is just try it connected one way, then the other. The dip will happen somewhere NEAR the crossover, not necessarily right AT the crossover. AL K. Quote Link to comment Share on other sites More sharing options...
TBrennan Posted January 10, 2003 Share Posted January 10, 2003 That's intersting. And no, I'm not going away. Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted January 11, 2003 Share Posted January 11, 2003 Brennan, Too bad! Al K. Quote Link to comment Share on other sites More sharing options...
Q-Man Posted January 11, 2003 Author Share Posted January 11, 2003 I don't want this to turn into a family feud, but these are my test results from last night. The sound level meter 3' in front of the speaker with warble tones. I changed the 288 driver, that I bought a few weeks ago to one that I bought a couple of years ago.The 288 I was using is called (new 288), the one I switched to is called (old 288). The old 288 is better from 400Hz. to 630Hz., see below. But it still has a dip in that range. Then I tried the AL-2, and the AA networks. These networks are better then the ALK and eliminate the dip. The AA seemed to be a little more consistent, so I tested the compleat range of the Klipschorn with the AA, and the AK-2. I will now try the AL-3, AK-3, and the Altec networks. You can see that the 288 is about 3db louder then the K-55, but this (+) 3db seems to match the out put of the bass horn better then the K-55. I now wonder why Klipsch tames the out put of the K-55???? Any ideas here? Al, I'll try reversing the polarity of the 288 on your network and see if the dip goes away. I'll do this before trying any more networks and report back. New 288 Old 288 Old 288 Old 288 K-Horn ALK, ALK, AL-2 AA Stock Tap,5,2 Tap,5,2 AK-2 31.5 HZ. 91 91 50 106 103 63 102 104 80 101 101 100 104 104 125 101 102 160 100 100 200 94 95 250 90 90 92 90 94 315 89 89 92 94 91 400 86 91 96 97 94 500 87 94 101 97 94 630 90 94 97 96 95 800 94 98 97 98 95 1kHZ. 98 99 96 99 95 1.25 98 99 99 98 93 1.6 97 99 99 99 94 2 96 98 97 97 94 2.5 100 96 3.15 99 93 4 98 93 5 99 96 6.3 99 101 8 94 98 10 94 94 Sorry, this doesn't look like the way I typed it. I lost the 40Hz. line. The Old 288AA and the stock Klipschprn, AK-2 columns both had a 102db reading at 40Hz. The 80 Hz. line is off to the right, both had a 101db reading. I tried to edit it, but it gets worst. I try something different next time. Quote Link to comment Share on other sites More sharing options...
Q-Man Posted January 11, 2003 Author Share Posted January 11, 2003 These are the results of the 288 with reversing the polarity on the ALK. It helped the dip at 315, and 400Hz. by 3db. I still don't think it increased it enought. ........288,ALK..........288,ALK.........288,AA.. .......................Polarity.................. .......................Reversed.................. 250Hz...90...............90..............90...... 315.....89...............92..............94...... 400.....91...............94..............97...... 500.....94...............94..............97...... 630.....94...............95..............96...... 800.....98...............98..............98...... 1kHz....99...............99..............99...... 1.25....99...............100.............98...... 1.6.....99...............100.............98...... 2.......98...............98..............97...... Thus far it looks like I'll be using the AA or the AK-3 network with the 288 driver. I'll be asking some of you about this mod that you did on your AA's. Quote Link to comment Share on other sites More sharing options...
Q-Man Posted January 11, 2003 Author Share Posted January 11, 2003 I couldn't change the 16 ohm diaphragms in the 288 to the 8 ohm ones. The 8 ohm diaphragms require slighy longer screws to hold it down. I'll have to pick some up and try it again. I now know why they call a tangerine phasing plug by that name. Quote Link to comment Share on other sites More sharing options...
Q-Man Posted January 11, 2003 Author Share Posted January 11, 2003 I went a head and tried the Altec 8ohm 500Hz. network anyway. I wanted to measure the Klipschorn bass out put with a 500Hz. crossover. The bass horn has more of a dip in it's frequency respone with this network from 250 to 400Hz. The mids read about the same for the 288 as it did with the AA. The highs drop off at 8kHz., this may be because of the miss match of the 16 ohm driver and the 8 ohm network. The 288 should be good up to 15 to 16kHz. I'll have to try it again when I can swap out the diaphragm. I think it's time to listen to some music with the 288/AA combination, and now do an A,B with the Stock AK-2 Klipschorn. Tom, Getting back to the active crossover. That's what I did understand about using an active crossover from what I read. That's why I was wondering if I could use it after the amp. That's all I need now, is some more amps around the house :-). Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted January 11, 2003 Share Posted January 11, 2003 Qman, Those last numbers don't look to bad, actually. Remember that you can only expect to get the frequency response to within about += 5 dB. You will also find that the point to point testing like that tends to mask what is really going on. A warble tone gives you an average of what is happening over the range it's warbeling, that is usually 1/3 octave. It will also drive you bananas becasue you seem to get different readings every time you test! By the way, if you put the html command "pre" just before your table of numbers it should help keep your columbs in line. Enclose the "pre" in brackets <>. Al K. Quote Link to comment Share on other sites More sharing options...
Jim Cornell Posted January 12, 2003 Share Posted January 12, 2003 Im beginning to fell happy i reversed LOL Jim Quote Link to comment Share on other sites More sharing options...
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