Q-Man Posted February 24, 2003 Share Posted February 24, 2003 Here is a picture of the Altec 311-90 300Hz. horn that I picked up on ebay. Attached to this horn is an Altec 290-16K 16 ohm driver that I ordered from Jammin Jersey Music and PRO Sound. It's a 300Hz to 7000Hz. driver, and the horn barely fits in the Klipschorn top that I made for the 805B horn. I was pleased that I didn't have to build new tops to hold this horn. I've been comparing this mod to the stock K-Horn for almost two weeks now. This combo doesn't take any tweaking, it measures and sounds right, right out of the box. I first hooked up the 290 to the ALK network expecting to have to find the right tap setting to reduce it's volume by the appropriate amount. This wasn't necessary, the 5-2 tap that is used for the K-55 was perfect for the 290. I measured the 290/311's output from 315Hz. to 6300Hz and compared it to the K-55/400. It is with in (+) or (-) 1db of the K-55 except it doesn't have a 6000 Hz peak like the K-55, which is good. The ALK network was disapointing, it causes a dip of 5 db at 400Hz. and a dip of 3db at 500 Hz. on the 290. Since the output of the 290 is the same as the K-55 I hooked it up to the stock Klipsch network. Now I was very happy, the dip at 400 & 500 Hz. was gone. Therefore, I will be using this driver and horn with the Klipsch network and the ALK's will be put back on the shelf. I have to measure the ALK with the K-55/400 and see if it has this 400 to 500 Hz. dip. The 290/311 is smoother then the 288/805b. This combination is the one that I'm going to keep. The horn is built like a tank, no resonating here. This can be an easy mod for someone, since it seems to work so well with the Klipschorn network. All you have to do is hook them up and you will enjoy a much improved midrange. Of course you will need to build new tops. I'll post more pictures when I finish mine up, I now have to make them look good. I also need to watch for another pair of 311-90 horns. Great Plains Audio, the guy who bought Altec's tooling, will be making new 290 drivers sometime in June. I will wait to then and buy a new pair from him. I need them for my center channel K-Horn, not to mention the surrounds. I may need to ask a few of you some crossover questions, and it's time to pick up a book or two on designing them. I think I would like to build a crossover designed just for these drivers. Quote Link to comment Share on other sites More sharing options...
Q-Man Posted February 24, 2003 Author Share Posted February 24, 2003 That picture is bad,I'll try another one. Quote Link to comment Share on other sites More sharing options...
Q-Man Posted February 24, 2003 Author Share Posted February 24, 2003 Before I try another picture let me say one more thing. A friend of mine from N.Y. came down to get out of the snow for a while. He has a band up there and brought me some of the bands CD's. I had him play them while I switched back and forth between the stock Klipschorn and the Altec one. While I kept switching his comments kept flowing, and they reinforced my opinions of this mod. Here are just a few of his comments about the 290/311 and the JBL 2404H tweeter. "That's my guitar, and that's what it sounds like when we play live and in the studio." "That's me singing, and it's exactally what I sound like." "Hear that cymbal? that is what the so & so cymbal really sound like." I forgot the name he called the cymbal. His comments were all similar for the other instruments & vocals that he pointed out to me. He was very impressed and never heard his CD's sound like his actual live performance before. He did say that the stock Klipschorn does sound very good, but that it can't compare to the realism of the Altec/JBL mod. He described the mids and highs of the Klipschorn as sounding muffled and not the right pitch. More of a mellow cave like sound, having an echo effect. Well, you get the idea. I'll try to post a better picture. Quote Link to comment Share on other sites More sharing options...
Q-Man Posted February 24, 2003 Author Share Posted February 24, 2003 Let's see if this one is any better. Quote Link to comment Share on other sites More sharing options...
edster00 Posted February 25, 2003 Share Posted February 25, 2003 Wow Q-Man that is a heck of a mod! How tall is that speaker now? Quote Link to comment Share on other sites More sharing options...
Q-Man Posted February 25, 2003 Author Share Posted February 25, 2003 The speaker is 3 1/2" taller then the Klipschorn. It would be another 4" taller if I didn't drop the tweeter over the face of the Klipschorn bottom. I had to do it this way so they would fit under the shelf that is on top of my false corner arrangement. I can't raise the so called shelf any higher, because my front effect LaScalas still need to fit up there. Not to mention my soon to be center channel Klipschorn. Quote Link to comment Share on other sites More sharing options...
edster00 Posted February 25, 2003 Share Posted February 25, 2003 You know you will have to post more photos when you get your rig done...can't wait to see them! Quote Link to comment Share on other sites More sharing options...
Q-Man Posted March 9, 2003 Author Share Posted March 9, 2003 I've been listening to the ALK,290,311 for weeks now,and I switched to the AK-2 network last night. I measured the 290/311 after hooking it up and with the AK-2. I gained 3 to 4 db from 400 to 600 hz. This 3 db gain matches the rest of the 290's output above 600 Hz. From the measurements I thought that I would just go with the AK-2 and AK-3's. I did another A/B with the stock AK-2 Klipschorn and this mod for about three hours. The 290/311 sounded better then the K55/400, but not as good as it did with the ALK network. For the three hours I tried to convince myself that the AK-2's and yet to try AK-3's would be the way to go. I couldn't, the sound of the ALK is now burned into my memory. It not only makes the 290/311 sound better, but also the Klipsch bass horn. The bass horn is a little cleaner and more real sounding. Drums have more of a snap. Bass strings vibrate and change pitch or tone as they slow down to a stop, verses just making a single note. Here I am trying to discribe the difference in the bass horn sound with the ALK when I should be discussing the 290/311 sound, but I guess I already did that. The bass just surprised the heck out of me, it makes the Klipschorn bass sound almost as good as the University Classic. Quote Link to comment Share on other sites More sharing options...
djk Posted March 9, 2003 Share Posted March 9, 2003 I bought eight 290s out of a football stadium down south. Four of them were rusted solid. While digging the coils out and cleaning them up with new diaphragms I was playing some Leo Kottke through them full range. Was very tempted to make headphones with a pair and a coathanger. Transients are so hard they hurt, with no 'overhang' or 'ringing'. Quote Link to comment Share on other sites More sharing options...
Q-Man Posted March 10, 2003 Author Share Posted March 10, 2003 djk, Do you still have any of the 290s? Quote Link to comment Share on other sites More sharing options...
Q-Man Posted April 30, 2003 Author Share Posted April 30, 2003 Before I say much, I'll try to load a few pictures. I never know what they are going to look like once I resize them. The 290-16K driver and 311-90 horn next to the K-55 driver and 401 horn. Quote Link to comment Share on other sites More sharing options...
Q-Man Posted April 30, 2003 Author Share Posted April 30, 2003 Side View. Quote Link to comment Share on other sites More sharing options...
Q-Man Posted April 30, 2003 Author Share Posted April 30, 2003 Building of the new tops to hold the 311-90 horn and JBL2404H tweeter. Quote Link to comment Share on other sites More sharing options...
Q-Man Posted April 30, 2003 Author Share Posted April 30, 2003 The woofer half of the super AA that John Warren built for this mod. Quote Link to comment Share on other sites More sharing options...
Q-Man Posted April 30, 2003 Author Share Posted April 30, 2003 The tweeter and midrange half of the AA network. Quote Link to comment Share on other sites More sharing options...
John Warren Posted April 30, 2003 Share Posted April 30, 2003 I posted Q's pics below. Here is the 290/311 compared to the Klipsch plastic mid (forward looking aft). The side view, notice the difference in drivers!! The top-hat enclosure. Here are the AA-networks I assembled for Q. I took this pic before I shipped them, Notice all Hovlands!! Mr. Q does not mess around! Top-hat assembled and placed atop folded unit. Notice JBL 2404H tweeter beneath the mid horn. Bi-radial *baby cheeks* design offers 100°X100° beamwidth, response to 22kHz, power capacity >50W when crossover >6kHz. Pricey at $270 each new. Quote Link to comment Share on other sites More sharing options...
Q-Man Posted April 30, 2003 Author Share Posted April 30, 2003 I'll get back to this tomorrow, but I must first say a few words. I'm finally satisfied with what I'm hearing. So satisfied that I now have Four 311 horns and three 290 drivers, and four JBL 2404H tweeters. Enought to redo the front end of my home theater set up (mains and center channel). I need to find two more 311 horns and three more 290 drivers so I can fill in the rear. One of the 290 drivers may be going to Bill Hanuschak at Great Plains Audio for repair. First I have to swap out the diaphragm and see if that fixes it. If not then he said that I better let him take care of it. Bill was the head engineer at Altec when they were making these drivers and now bought all the tooling so he can keep producing them. He said that he should be making the 290 in a few months so I'll wait to buy the other three that I need from him. Talking to him today he told me that the 290 is the best sounding midrange driver that Altec ever made. It wasn't very popular because you have to use a tweeter with it, unlike the 288 and the other Altec drivers. I'm hearing things with such clarity now, things that were almost inaudible with the 55/400 and stock Klipsch network. I find that I don't have to listen to my music nearly as loud as I used to to enjoy it. This top end blends in with the Klipschorn bass horn very well. It's late for me, so I'm going to end this now. But, I must first thank John for the networks. His AA does a much better job for me then the ALK did. No more dip from 315Hz to 500Hz and they even improved the midrange clarity a little more. Later Guys, Q. Quote Link to comment Share on other sites More sharing options...
Q-Man Posted April 30, 2003 Author Share Posted April 30, 2003 John, You posted while I was adding the above. Thanks for helping out again. Quote Link to comment Share on other sites More sharing options...
J M O N Posted May 2, 2003 Share Posted May 2, 2003 Q-Man: Very nice work, as usual. That's a very interesting project. Have you been able to compare the 311 with the 511 or 811 horns? If so, how do they compare? Quote Link to comment Share on other sites More sharing options...
djk Posted May 2, 2003 Share Posted May 2, 2003 "Great Plains Audio for repair" I would not buy the new large format drivers from them, they're not made right. The cast iron 'snout' is missing, the driver is just a flat pancake. The 'snout' is needed to match up with the much lower taper rate of the 311 horn. 311/511/811 The 511E (kind of rare) can mount the 290, the adaptor needed to mount to the 511B/811B increases distortion. In general, the larger the horn, the smoother the response is in the lowest octave. The larger the throat on the driver, the lower the distortion (realizing that a 1" driver with a 2" throat adaptor is still a 1" driver). Quote Link to comment Share on other sites More sharing options...
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