sfogg Posted January 21, 2006 Share Posted January 21, 2006 Dean, What driver did you try going 2 way with? Shawn Quote Link to comment Share on other sites More sharing options...
Deang Posted January 21, 2006 Share Posted January 21, 2006 Oops, forgot about the low pass for the squawker -- you'll need to add a .10 or .11mH air core between the 44uF and tap 5. You should probably change the 2.4mH on the woofer to 2.0mH. Quote Link to comment Share on other sites More sharing options...
Deang Posted January 21, 2006 Share Posted January 21, 2006 The K-55 -- it sounded terrible. Just kidding -- the JBL 2470, which I suppose is almost as bad -- drops like a rock around 10kHz. You're right, it's not a valid comparison, I shouldn't have said what I said. Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted January 21, 2006 Share Posted January 21, 2006 Dean, 22+22 uF in place of the 40 uF is pushing the crossover even lower than 400 Hz. That isn't wise. Are you sure about those numbers? 40 uF and 3 mHy to ground sharpens the skirt and actually moves the crossover up slightly. This is much safer. Shawn, Advising a 400 Hz first order crossover be used with the Altec 902 is bad advice! You can boil nitro out of dynamite and chances are you won't get your head blown off, but would you advise somebody to do it ? Al K. Quote Link to comment Share on other sites More sharing options...
Deang Posted January 21, 2006 Share Posted January 21, 2006 It's based on a 6 ohm impedance. Should be right. Quote Link to comment Share on other sites More sharing options...
sfogg Posted January 21, 2006 Share Posted January 21, 2006 Al, "Advising a 400 Hz first order crossover be used with the Altec 902 is bad advice! " Those that have actually done it haven't had problems. Contrary to "blow them off the face of the Earth in short order" it has worked fine. Check out the various DIY home systems Altec users have come up with... often they run first order. Your basing your advice on specs, I'm basing mine on experience. I certainly wouldn't recommend it in a 800 seat theater but in a persons living room it will work fine for just about everyone that listens at any sort of sane levels. For 85dB levels at my listening position in my old room with the two way LaScala's I was measuring about 1/10 of a watt into the speakers. Peaks of nearly 100dB are all of 2w.... no problem. I ran mine up to peaks of 105dB per speaker at the listening position. And that was with the thinner 902-8A type diaphragms. That is not to say I don't think there are benefits to high slope crossovers (obviously since I'm running them) but a 902 will work first order for most users. Those that are trying to peel the paint off their walls shouldn't attempt this. Shawn Quote Link to comment Share on other sites More sharing options...
tofu Posted January 21, 2006 Author Share Posted January 21, 2006 crossover point shouldn't be an issue if i go with the 44uf value dean recommended Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted January 22, 2006 Share Posted January 22, 2006 Shawn, Again, yes, YOU got away with doing it. For a while, then you moved away from it to the extreme-slope netwroks. That was the right move. With that network you could have distroyed the neighbors hearing before hurting the driver. This says even you considered it a temperary arangement. To suggest it is a good idea is bad advice! You got away with it becasue you didn't put much power into it, the transformer shorts out the extreme lows and you had it attenuated. Others may not have that series of circumstances and then a nice driver gets it's diaphragm smashed into the phase plug becasue of a temperary lashup! The 902 was not intended to operate down to and below 400 Hz. That amounts to abuse. I advise doing it properly in the first place by moving the crossover up where it should be and with a slightly higher order filter. Only the Khorn NEEDS a 400 Hz or lower crossover. Al K. Quote Link to comment Share on other sites More sharing options...
Deang Posted January 22, 2006 Share Posted January 22, 2006 Yes Shawn, please leave giving bad advice to me. I've spent a lot of time honing that skill. Quote Link to comment Share on other sites More sharing options...
sfogg Posted January 22, 2006 Share Posted January 22, 2006 Al, "Again, yes, YOU got away with doing it." As have others. I have yet to see complaints about blowing the driver off the face of the Earth. "the transformer shorts out the extreme lows and you had it attenuated. Others may not have that series of circumstances " I'm suggestion this to someone with those exact same circumstances. "This says even you considered it a temperary arangement." And my decision to move to the ES had nothing to do with power handling. The number for power usage I posted earlier was power to the entire speaker. Since the driver was being attenuated by 7dB relative to the woofer less then 1/4 of that power was going to the 902. IOW, during full bore THX Ref. Level playback (which many consider too loud) the driver was receiving less then 1/2 a watt. It had *zero* problems with that at 400hz first order. I moved to the ES mostly because I wanted to hear what limiting driver interaction would sound as I have been curious about that for years from reading about Joseph Audio/JSE speakers and it seemed like a good way around the different path lengths of the horns. Shawn Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted January 22, 2006 Share Posted January 22, 2006 Shawn:"I moved to the ES mostly because I wanted to hear what limiting driver interaction would sound as I have been curious about that for years from reading about Joseph Audio/JSE speakers and it seemed like a good way around the different path lengths of the horns."I think you indicated above that your ES networks are still for sale, is that right? This discussion has been addressing 400Hz, but I'm guessing the ES networks you made are the 500HZ version (?). Your small 'For Sale' sign caught my eye.I know this is off the Altec topic, but what did you say the insertion losses were with those? I'm curious about this in terms of how it would relate to the Lexicon/bridged SE OTL combination.Thanks,Erik Quote Link to comment Share on other sites More sharing options...
sfogg Posted January 22, 2006 Share Posted January 22, 2006 Erik, Actually mine are the ES600Ts. I built the ALK Type A's I was running but the ES networks Al built. "I know this is off the Altec topic, but what did you say the insertion losses were with those? I'm curious about this in terms of how it would relate to the Lexicon/bridged SE OTL combination." I forget the exact number but it was a couple of dB loss through the crossover. With the LaScala's running the ES600T and the single SE-OTL I could hit high 90s SPLs with the LaScala's high passed to the sub. Run full range they could do about 95dB (together) before the SE-OTL ran out of juice and started to get nasty. For SPL comparison sake the 95dB SPL level is what you would hit max. with the volume control on the Lex at -10dB. In your room though the power required could be different though of course. The ES600T wouldn't work for you with the K'Horns though as the crossover is too high for the K'Horns bass bin. Shawn Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted January 22, 2006 Share Posted January 22, 2006 Shawn: Got it, thanks for the information. Also: "The ES600T wouldn't work for you with the K'Horns though as the crossover is too high for the K'Horns bass bin." I Was just comparing the schematics of the ES versions to see what changes would need to be made. In my case, it would be better to just build them from scratch. I'm really curious about the ES networks, but the Klipsch type 'As' I just made sound excellent with the SE OTLs. Erik Quote Link to comment Share on other sites More sharing options...
tigerwoodKhorns Posted January 22, 2006 Share Posted January 22, 2006 Dean, Were you happy with the JBL 2470 down at 400 hz? I will be running them down to 400 hz with 24 db slopes on Altec 511b's. I'm not concerned about the 10 khz rolloff because I will be using JBL 2404's. What frequency should I cross the squaker and tweeter at (I assumed that I will start at 5700 hz). Chris Quote Link to comment Share on other sites More sharing options...
Deang Posted January 22, 2006 Share Posted January 22, 2006 I've been using the 2470's ever since I got them. I took some measurements with the Behringer's RTA last weekend using the Stereophile Test CD. Single tone, warble tone, and pink noise showed suprisingly strong output in the 350-450Hz where I had expected some problems. It was 4-5dB down at 400Hz, which wasn't much different then what I got with the K401/K-55. I didn't think the Trachorn would do that well, but I guess it does better with the 2470 than the 2350 horn JBL used to make the FR plot. Beats me. I use two networks: a modified Type AA and the 'Super' AA. Both have 1st order/6kHz squawker filters Quote Link to comment Share on other sites More sharing options...
tofu Posted January 22, 2006 Author Share Posted January 22, 2006 so, i'm ready to start rewiring my networks today. just one last question remains unanswered. dean says the 44uf value will raise my crossover to ~600hz (i say ~600 because it will be more along the lines of 44.4uf) but al says that will lower my crossover point BELOW 400hz.. i value both of your information highly, and when you start contradicting eachother with non opinionated issues, it really confuses me []. can i get a final answer on this? Quote Link to comment Share on other sites More sharing options...
Deang Posted January 22, 2006 Share Posted January 22, 2006 If the primary cap is based on 6 ohms -- it's 44uF. If it's based on 8 ohms -- it's 33uF. I just talked to Al a few minutes ago who was sitting on his arse watching TV of all things. I'm calling him back in a bit and then one of us will post something confusing and convoluted. Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted January 22, 2006 Share Posted January 22, 2006 Tofu, Dean and I talked earlier today about this 44 uF business. I think we are comparing apples to oranges. Anyhow, we will be working on this again later. Don't start cutting wires until we figure it out! Al K. Quote Link to comment Share on other sites More sharing options...
tofu Posted January 22, 2006 Author Share Posted January 22, 2006 thanks for the help guys. i appreciate it. Quote Link to comment Share on other sites More sharing options...
sfogg Posted January 22, 2006 Share Posted January 22, 2006 " I will be using JBL 2404's. What frequency should I cross the squaker and tweeter at (I assumed that I will start at 5700 hz)." If your squawker will get high enough go for a 8k or higher crossover on the 2404s. They sound best above 8k. Shawn Quote Link to comment Share on other sites More sharing options...
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