chris haberland Posted March 3, 2005 Share Posted March 3, 2005 Ever since i posted my thread on my home built Khorns, your comments on using the 290 vs the 288's has stayed with me, even more so now that the present networks im using do not work well.I have the tweeters disconnected for now as there is smearing and a loss of detail due to the 311's rolling off at about 15000hz,this is totally interfereing with the tweeter.My first costly mistake and im sure there will be more.I read your threads on the Altec forum and see you have spent alot of time and money experimenting to achieve the best sounding Khorn.What i would like to try before going to the expense of buying new drivers is try a modified AKL Type A network.This will be a third order cut off at 300hz,possibly similiar to what you have.The 288's were not designed to go this low but there are people that have gone lower than this with success, at what compromise im not sure, maybe you can answer this for me.I think the diaphrams will hold up because they have gone through a lot more with the present networks being a first order.Thank god for that, they are brand new at a $100.00 a pop.My question really is will there be a large compromise in the sound quality if i connect them to this new network, roll off for example,ect.I know you have experimented alot on this subject, so your responce on this subect will be of great value to me.I posted a picture of the Filter design.Regards Chris. Quote Link to comment Share on other sites More sharing options...
chris haberland Posted March 3, 2005 Author Share Posted March 3, 2005 Filter Quote Link to comment Share on other sites More sharing options...
sunnysal Posted March 3, 2005 Share Posted March 3, 2005 over at the altec forum it is claimed that the 299 and 288 can both be used down to 300hz if power levels are kept to hifi levels and not for pro use. though the phenolic diaphram in the 290 seems to me to be better suited to low fequency use...q-man will certainly ring in but I would also post this question over at the altec board. tony Quote Link to comment Share on other sites More sharing options...
J.4knee Posted March 3, 2005 Share Posted March 3, 2005 Altec forum!?! URL please Quote Link to comment Share on other sites More sharing options...
Tom Mobley Posted March 3, 2005 Share Posted March 3, 2005 Here's one that works well for me.... hehehehe Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted March 3, 2005 Share Posted March 3, 2005 J.4, Here's the Altec / JBL group. The format is very similar to this one. http://audioheritage.csdco.com/vbulletin/index.php?s= Chris, Ah Ha! Caught you giving away my free designs to the world! AL K. Quote Link to comment Share on other sites More sharing options...
Deang Posted March 3, 2005 Share Posted March 3, 2005 Ha! I even have more sense than that -- I sell them!! Quote Link to comment Share on other sites More sharing options...
chris haberland Posted March 3, 2005 Author Share Posted March 3, 2005 I have been to the Altec forum.From what i have read Q-man is the guy to ask.I know they will go down to 300hz, some guys have gone down as low as 200hz, but will they preform well at these cutoff points.Altecs spects on the 288's is 500hz conservatively speaking im sure.I agree that the volume levels in home use will be safe and no damage should occurr and the fact that the network im going to use is fairly steep, 18db per octave, but will they perform well is the big question.Chris. Quote Link to comment Share on other sites More sharing options...
chris haberland Posted March 3, 2005 Author Share Posted March 3, 2005 Thanks Al i will check it out.Didnt i say Q-man is the only one aloud to look at those schematics,oops, sorry Al. Quote Link to comment Share on other sites More sharing options...
Q-Man Posted March 3, 2005 Share Posted March 3, 2005 You could find more information on the Klipsch Forum. I experimented for about a year and I posted results and my opinions almost every few days. I still have a pair of 288 drivers and 805-B horns laying around. I should sell them , but I've been thinking that I'll build myself a pair of speakers to use on the patio one of these days. I kept finding a hole around 400Hz to 500Hz with the 288 driver. There were things that I could hear out of the K-55 and K-401 that I couldn't hear from the 288 with the 805-B and 311-90 horns. I keep a pair of stock Klipschorns set up in one room that I use as a reference speaker. They are good to A/B againts. The 290-16K or 16L drivers are hard to find, but they are cheaper then the 288's. No one thinks about using the 290 drivers, but everyone wants to buy and use the 311-90 horn. I tried this horn after an Altec nut told me that it was the best sounding horn that Altec ever made. Even with these 300 hz drivers and horns I cross them over at 400Hz. This keeps them out of their distortion range. Klipsch would have liked to cross over the 250Hz K-55 driver lower then 400hz, but also had to keep it higher. John warren can explain the reasons why better then I can. Once I decided that the 290 and 311 were the way to go it was time to work on the network. I tried the AK-2, AK-3, AA, ALK, and Warrens hot rod AA. I disliked the stock AA the most and Warrens custom AA the best. I thought things couldn't get much better. this combination was sooooo smooth and real sounding. I decided to send John a horn and driver to test and measure. He found out that the horn has a nasty peak in it. Reflections from the mouth back into the throat. He designed a network with a notch filter in it to take care of this problem. He was shocked and very impressed with the sound of this top end. I was shocked when I did an A/B with his custom AA network that I was using and the network designed for the 290 and 311. I never would have believed that what I was listening to could get better yet. If you go with 290 drivers you need to have John build you this network. You can use the network with the K-77 tweeter for now, but later you have to buy the JBL 2404-H tweeter. The JBL tweeter is another wow factor. By the way, I like the way you mounted your tweeter. It looks alot better then mine. I will have to do that one of these days. I'm about to start working on another mod where the driver can be crossed over at 300Hz and is current stuff instead of vintage. I will have to have John design a network for this when I get farther along and weed out some stuff. Quote Link to comment Share on other sites More sharing options...
Deang Posted March 3, 2005 Share Posted March 3, 2005 I've heard John say the Klipschorn bass horn has severe problems past 300Hz. What do you think? Quote Link to comment Share on other sites More sharing options...
J.4knee Posted March 3, 2005 Share Posted March 3, 2005 Looks great Dean, but what are all those squiggly lines? Quote Link to comment Share on other sites More sharing options...
Deang Posted March 3, 2005 Share Posted March 3, 2005 Hell, I don't know, I was hoping someone would tell me. O.K., yeah, she craps out at 300, but she pops right back up, and the midrange overlaps some of that too. If it stresses anyone out that bad, they can EQ it. Quote Link to comment Share on other sites More sharing options...
ben. Posted March 3, 2005 Share Posted March 3, 2005 If I could pick one frequency to have a dip like that, it would be between 300 and 400 Hz! Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted March 4, 2005 Share Posted March 4, 2005 Guys, 300 Hz is the best place to cross it over if you can find a squawker that will go down to 300 Hz. That Altec 311 with the right driver WILL! Crossing it at 300 will mean a higher efficiency speaker. This is why I keep screaming that an extreme-slope cross at 300 will protect the squawker driver from energy below 300 Hz at high power and hand you a few dB extra efficincy to boot! With the 3rd order network you should still be able to run it safely at moderate power levels. Al K. Quote Link to comment Share on other sites More sharing options...
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