chops Posted June 22, 2006 Share Posted June 22, 2006 The 902s just came in! Well, actually, they got here an hour ago, at 4:00 EST. After breezing through the first page of this thread again, making the appropriate changes to the networks, removing the K55's and adapters, and mounting the 902 drivers, 45 minutes later I have Altec 902-8B drivers projecting sound into my room. Once I had the first one completed, I went ahead and powered up the system. I played a minute or so of music just to see how close the K55 on tap #3 was to the 902 on tap #2. I have to admit, they were an almost identical match in output. Of course, this the first time ever for tap #2 to be used, plus there's no telling how long these 902s have been sitting, so it probably wouldn't be fair to pass any judgement yet on the sound. Not to mention that I'm listening to Pipe Dreams through them off of the interent which eventhough it is a good recording, it's definately not CD quality. I will say this though, these 902s seem to be a little rolled off on the top end, almost too much. However, I will play some various recordings through them for a while and see if they open up anymore or not. If they don't, I'll be going back to a 3-way, which will most likely be the case. I'll post a few pics in a few. I just said the word "few" a few times in a row! LOL [] Quote Link to comment Share on other sites More sharing options...
chops Posted June 22, 2006 Author Share Posted June 22, 2006 And here's the pics... This first pic is of the modified Type B, which is considered a Type CS II network Now converted to a 2-way. I don't know what it would be called now... Type AC (AlCorn) maybe? Tap #2 connection... Tap #2 connection, just a different angle with a little dust and cat-fuzz... Comparison of the 902 vs K-55... This one I purposely boosted the contrast to help show what's inside the driver. Is that the "tangerine" phase plug everyone keeps referring to? Driver for left channel mounted to 511B horn. As you can see in the background, Lil' Sammie approves!.... Naturally! Right channel complete and powered up... Quote Link to comment Share on other sites More sharing options...
steamer Posted June 22, 2006 Share Posted June 22, 2006 The 902s just came in! Well, actually, they got here an hour ago, at 4:00 EST. After breezing through the first page of this thread again, making the appropriate changes to the networks, removing the K55's and adapters, and mounting the 902 drivers, 45 minutes later I have Altec 902-8B drivers projecting sound into my room. Once I had the first one completed, I went ahead and powered up the system. I played a minute or so of music just to see how close the K55 on tap #3 was to the 902 on tap #2. I have to admit, they were an almost identical match in output. Of course, this the first time ever for tap #2 to be used, plus there's no telling how long these 902s have been sitting, so it probably wouldn't be fair to pass any judgement yet on the sound. Not to mention that I'm listening to Pipe Dreams through them off of the interent which eventhough it is a good recording, it's definately not CD quality. I will say this though, these 902s seem to be a little rolled off on the top end, almost too much. However, I will play some various recordings through them for a while and see if they open up anymore or not. If they don't, I'll be going back to a 3-way, which will most likely be the case. I'll post a few pics in a few. I just said the word "few" a few times in a row! LOL [] Chops, I at first I had the same impression with mine running 2way.After listening for awhile I find that to be the case off axis.But on axis I felt it was fine.A different sounding driver than the K-55 and K-77 tweeter(in 3way) for sure.After listening to many recordings over the last 6 months I have grown very fond of the sound.Give it some time. As you know I run an active x-over vs. passive so what I am hearing isnt the same.I look forward to your further impressions. Greg Quote Link to comment Share on other sites More sharing options...
Guest " " Posted June 22, 2006 Share Posted June 22, 2006 The 902s just came in! Well, actually, they got here an hour ago, at 4:00 EST. After breezing through the first page of this thread again, making the appropriate changes to the networks, removing the K55's and adapters, and mounting the 902 drivers, 45 minutes later I have Altec 902-8B drivers projecting sound into my room. Once I had the first one completed, I went ahead and powered up the system. I played a minute or so of music just to see how close the K55 on tap #3 was to the 902 on tap #2. I have to admit, they were an almost identical match in output. Of course, this the first time ever for tap #2 to be used, plus there's no telling how long these 902s have been sitting, so it probably wouldn't be fair to pass any judgement yet on the sound. Not to mention that I'm listening to Pipe Dreams through them off of the interent which eventhough it is a good recording, it's definately not CD quality. I will say this though, these 902s seem to be a little rolled off on the top end, almost too much. However, I will play some various recordings through them for a while and see if they open up anymore or not. If they don't, I'll be going back to a 3-way, which will most likely be the case. I'll post a few pics in a few. I just said the word "few" a few times in a row! LOL [] the rolling off at the top you are noticing is probally due to the squawker autoformer you are using. The autoformer was not desinged to pass high frequencies to a tweeter. You need to talk to AL about obtaining a set of his Tweeter attenuator 's. These attenuators will allow adjustments to tweeter output while not acting as an inline indictor which is causing the rolloff you are refering to. If you want an objective look at your crossover mod, can you post a diagram. Quote Link to comment Share on other sites More sharing options...
BEC Posted June 22, 2006 Share Posted June 22, 2006 speakerfritz said "the rolling off at the top you are noticing is probally due to the squawker autoformer you are using. The autoformer was not desinged to pass high frequencies to a tweeter." That is not the problem. The T2A is in fact meant to attenuate either a tweeter or squawker or both. It is good to well over 20 khz. Bob Crites Quote Link to comment Share on other sites More sharing options...
cjgeraci Posted June 22, 2006 Share Posted June 22, 2006 "the rolling off at the top you are noticing is probally due to the squawker autoformer you are using. The autoformer was not desinged to pass high frequencies to a tweeter. You need to talk to AL about obtaining a set of his Tweeter attenuator 's. These attenuators will allow adjustments to tweeter output while not acting as an inline indictor which is causing the rolloff you are refering to. If you want an objective look at your crossover mod, can you post a diagram." I agree with Bob - the autoformer is not the problem. Certainly listen to it for quite a while before you make a decision, but . . . . even some 902 Altec owners have been known to add a little sparkle on top with a supertweeter. Let your ears be the judge, but you may come to the same conclusion that I did - and convert your fine full range Altec driver into a squawker (going to 3 way). Carl Quote Link to comment Share on other sites More sharing options...
chops Posted June 22, 2006 Author Share Posted June 22, 2006 speakerfritz said "the rolling off at the top you are noticing is probally due to the squawker autoformer you are using. The autoformer was not desinged to pass high frequencies to a tweeter." That is not the problem. The T2A is in fact meant to attenuate either a tweeter or squawker or both. It is good to well over 20 khz. Bob Crites Thanks for clearing that up Bob. Honestly, I didn't think the T2A was the problem either since it has had the squawker and tweeter connected to it for the past 27 years, and after installing new caps and your CT125 tweeters, there was plenty of treble. However, from all of the measurements I've been taking lately of the system, there is a consistant -3dB drop or so from 18kHz and above. And all of these measurements were taken with the tweeters front mounted, per yours and Deans recommendations. This plot shows the fullrange output of the left speaker at 1 meter distance. (pre-Altec 902 drivers) Quote Link to comment Share on other sites More sharing options...
BEC Posted June 22, 2006 Share Posted June 22, 2006 Chops, I found part of it for you. Bob 270400.pdf Quote Link to comment Share on other sites More sharing options...
chops Posted June 22, 2006 Author Share Posted June 22, 2006 Chops, I found part of it for you. Bob Bob, I kinda figured that as well, but didn't want to admit it. LOL A lot of mics that I've seen have this same problem though. What other mics are out there at a decent price that can be used? Charles Quote Link to comment Share on other sites More sharing options...
BEC Posted June 22, 2006 Share Posted June 22, 2006 Chops, The mic is fine, just realize the bit of roll off at the top end. You don't listen to the mic. Besides you should see what the human ear roll off is in that frequency area. Bob Quote Link to comment Share on other sites More sharing options...
chops Posted June 22, 2006 Author Share Posted June 22, 2006 Yeah, that's true. Thanks Bob for the reassurance. [] Quote Link to comment Share on other sites More sharing options...
Guest " " Posted June 22, 2006 Share Posted June 22, 2006 speakerfritz said "the rolling off at the top you are noticing is probally due to the squawker autoformer you are using. The autoformer was not desinged to pass high frequencies to a tweeter." That is not the problem. The T2A is in fact meant to attenuate either a tweeter or squawker or both. It is good to well over 20 khz. Bob Crites it may pass signal over 20khz, but can you say that their is no loss or rolloff? of course not. the attach diagram even defines the loss at any given possible pin configuration. notice the indictance values as well. I do not see any possible tap configurations that would result in no loss.... 0 - 4 -3db 0 - 3 -6db 0 - 2 -9db 0 - 1 -12db Quote Link to comment Share on other sites More sharing options...
Guest " " Posted June 22, 2006 Share Posted June 22, 2006 speakerfritz said "the rolling off at the top you are noticing is probally due to the squawker autoformer you are using. The autoformer was not desinged to pass high frequencies to a tweeter." That is not the problem. The T2A is in fact meant to attenuate either a tweeter or squawker or both. It is good to well over 20 khz. Bob Crites it may pass signal over 20khz, but can you say that their is no loss or rolloff? of course not. the attach diagram even defines the loss at any given possible pin configuration. notice the indictance values as well. I do not see any possible tap configurations that would result in no loss.... 0 - 4 -3db 0 - 3 -6db 0 - 2 -9db 0 - 1 -12db Quote Link to comment Share on other sites More sharing options...
Guest " " Posted June 22, 2006 Share Posted June 22, 2006 speakerfritz said "the rolling off at the top you are noticing is probally due to the squawker autoformer you are using. The autoformer was not desinged to pass high frequencies to a tweeter." That is not the problem. The T2A is in fact meant to attenuate either a tweeter or squawker or both. It is good to well over 20 khz. Bob Crites it may pass signal over 20khz, but can you say that their is no loss or rolloff? of course not. the attach diagram even defines the loss at any given possible pin configuration. notice the indictance values as well. I do not see any possible tap configurations that would result in no loss.... 0 - 4 -3db 0 - 3 -6db 0 - 2 -9db 0 - 1 -12db Quote Link to comment Share on other sites More sharing options...
Guest " " Posted June 22, 2006 Share Posted June 22, 2006 speakerfritz said "the rolling off at the top you are noticing is probally due to the squawker autoformer you are using. The autoformer was not desinged to pass high frequencies to a tweeter." That is not the problem. The T2A is in fact meant to attenuate either a tweeter or squawker or both. It is good to well over 20 khz. Bob Crites it may pass signal over 20khz, but can you say that their is no loss or rolloff? of course not. the attach diagram even defines the loss at any given possible pin configuration. notice the indictance values as well. I do not see any possible tap configurations that would result in no loss.... 0 - 4 -3db 0 - 3 -6db 0 - 2 -9db 0 - 1 -12db Quote Link to comment Share on other sites More sharing options...
Guest " " Posted June 22, 2006 Share Posted June 22, 2006 speakerfritz said "the rolling off at the top you are noticing is probally due to the squawker autoformer you are using. The autoformer was not desinged to pass high frequencies to a tweeter." That is not the problem. The T2A is in fact meant to attenuate either a tweeter or squawker or both. It is good to well over 20 khz. Bob Crites it may pass signal over 20khz, but can you say that their is no loss or rolloff? of course not. the attach diagram even defines the loss at any given possible pin configuration. notice the indictance values as well. I do not see any possible tap configurations that would result in no loss.... 0 - 4 -3db 0 - 3 -6db 0 - 2 -9db 0 - 1 -12db Quote Link to comment Share on other sites More sharing options...
Guest " " Posted June 22, 2006 Share Posted June 22, 2006 speakerfritz said "the rolling off at the top you are noticing is probally due to the squawker autoformer you are using. The autoformer was not desinged to pass high frequencies to a tweeter." That is not the problem. The T2A is in fact meant to attenuate either a tweeter or squawker or both. It is good to well over 20 khz. Bob Crites it may pass signal over 20khz, but can you say that their is no loss or rolloff? of course not. the attach diagram even defines the loss at any given possible pin configuration. notice the indictance values as well. I do not see any possible tap configurations that would result in no loss.... 0 - 4 -3db 0 - 3 -6db 0 - 2 -9db 0 - 1 -12db Quote Link to comment Share on other sites More sharing options...
BEC Posted June 22, 2006 Share Posted June 22, 2006 Wow, We heard you all ready. Yes, the job of the autotransformer is to attenuate. But it attenuates linearly. Set the tap for 3 db and it will attenuate the entire audio range 3 db. Not more at higher frequencies. Bob Quote Link to comment Share on other sites More sharing options...
chops Posted June 22, 2006 Author Share Posted June 22, 2006 Wow, We heard you all ready. I guess the 6th time is a charm! LOL Yes, the job of the autotransformer is to attenuate. But it attenuates linearly. Set the tap for 3 db and it will attenuate the entire audio range 3 db. Not more at higher frequencies. Bob Again, exactly what I was thinking. It's like turning the volume up or down on a preamp/receiver. The entire range changes SPL at the same rate, not just one part of it. ---------------------- All if this reminds me of a little saying my father always says... "Some people just know enough to be dangerous." Quote Link to comment Share on other sites More sharing options...
chops Posted June 23, 2006 Author Share Posted June 23, 2006 Well, after listening to these 902 drivers for a while now, I'm really liking what I'm hearing. Their top end kind of reminds me of the alnico K77s, except a bit more refined. Last night, I played Madonna's latest CD, and I have to admit, these Altec drivers/horns did an excellent job. I was running the system at a sustained 101dB in the sweet spot, and I was very impressed and pleased with the sound. Even my "other" brother who isn't to fond of horns said that he really likes this combination. He said "Finally, a set of horns that don't chase you out of the room!" Quote Link to comment Share on other sites More sharing options...
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