Jump to content

longdrive03

Regulars
  • Posts

    816
  • Joined

  • Last visited

Posts posted by longdrive03

  1. DJK:

    If the 2.5mh and 68uf filter is for a 4 ohm woofer then a 5mh and 34uf filter would be correct for a single KP-22-E since it's an 8 ohm woofer? Correct?

    Likewise, if you use a 2.5mh and 68uf filter on a single KP-22-E (8 ohm) woofer the xover point will be idoubled (approximately 1500 hz) instead of the 750Hz for the HII??? Correct?

    I used a 2.5mh 68uf filter on one KP-22 -E so I think I need to change to 5mh and 34uf to get the right xover point.

  2. See the below thread about my initials questions and responses. Please tell me where I'm going wrong on the below plan.

    I think I'll take a trial run at the Super Heresy with 2 KP-22-E woofers per side, another brand mid driver (either on a K-703 horn or a 5 x 15" horn) and a K-79-K tweeter. DJK suggested in the below thread a 6 cf box SBB4 alignment with some eq tuned to around 30 hz. I've got 2 T2A autoformers that I'll use on the mid which is supposedly 110db 1w/1m. The KP-22-E measures 94.99 db on my WT2 so I should get 6 more db wiring two in parallel for 4 ohm load and using close placement.

    Looks like I'll need about 9db attenuation from the T2A using tap 2. I understand this tap has a factor of 8 times the driver impedance (17.5 at 750Hz) for 140 ohm so I'll use a 1.5uf cap before the T2A per the HII xover layout. The HII xover shows a 2.5mh coil and 68uf cap so I'll use a 1.25mh coil and 136uf cap for the dual woofers. I'll use the HII 18db on the tweeter (double 1.5uf and .16mh coil). Any problems with using double 2 uf with the .16mh coil like the KLF20 uses with the K-79 tweeter for a slightly lower xover point?

    Questions: Does anyone know the impedance of the 2.5mh coil in the HII design? Seems like I saw somewhere that it was around .3 ohms? By reducing to a 1.25mh what impedance should I look for on the coil? What about baffle step correction - does it need it? Internal cabinet size will probably be 48" tall, 15" wide and 15" deep (with some possible variation of the width and/or depth? Any suggestions on how high to place the bottom woofer on the front baffle?

    Gosh this guy asks a lot of questions! I know with all the technical know how on this forum some kind soul can help. Please feel free to show me the error of my ways and criticize, suggest, or boo at will. Thanks.

  3. Anyone ever double up the 12" Heresy woofer to get higher output? What about wiring two woofers in parallel to get a 4 ohm load and installing one in a seal box and the other in a ported box. The woofer specs really favor a ported box. Any problems with this alignment?

    I realize you could build a Cornwall to get more output and lower bass but I have 12" woofers and not a 15" woofer. Could still add a sub for extra low support.

  4. I did a sweep on my woofer tester II and this TU 150 driver has high impedance. At 742 Hz it is 17.5 ohms and at 6057Hz it is 36.52 ohm. at 1255 Hz it is 78.6 Hz???. I don't have the equipment to do a frequency response graph (or the know how) but this sure looks different than the K-67 driver impedance values I measured. I'm concerned about the response of the TU150.

  5. Gotcha. I think! I'll try the padding resistors and calculate the xover values at the proper frequencies based on the driver impedance at those frequencies and give it a go. They are a lot cheaper than the autoformer. I live just down the road from Bob Crites so I can get some quickly if need be. Thanks again, I appreciate all your input.

  6. Congrats on the H II's. I just built a set for my friend for his garage. Delivered them yesterday and he hooked them up in his listening room. We hooked one H up on the left and his Magnepan was on the right. Turned them on and you could hear the H clearly and we weren't sure the Maggie was on! He's rethinking the whole garage thing now! He has two in wall subs I built for him that match nicely. Maggies may end up in the garage!

    Listen to them for a while. They grow on you!

  7. Thanks for the responses guys. I guess I could get off my lazy butt and hook it up and listen, huh? I think my problem may be solved anyway. I have quite a few 7 x 10" tractrix horns used in some Klipsch models which don't have a built in phase plug. I have the screw in driver assembly with a phase plug but more horns than assemblies. I have some drivers assemblies without phase plugs so I was going to give it a shot but tonight I got more drivers with phase plugs so I'm happy for now. I saw on the PE board a reference to a dome tweeter loaded in a round "waveguide" which was interesting. However, the waveguide didn't have the efficiency of a horn. Thanks for the help.

  8. The drivers are a TU 150 China made ("Design in USA) and are very large and heavy. They sound surprising good and clear when hooked up as the mid to my Heresy's I'm building for a friend. Definitely hotter than the Atlas K-55-G mid driver I'm using in the Heresy's which is 16 ohms but measures around 11 ohms. The TU 150 measures 15 ohms. I don't have test equipment but using the same autoformer taps on the Tu 150 it is clearly hotter. I may go with the 12db tap on the T2A and just add another woofer for the next set to bring up the bass. Looks like I would need 19-20 db padding if the 114db rating is valid. Here's a link to the driver off ebay.

    I read the discussion about autoformer versus 2 resistor attenuation and it appears the autoformer gives much better response. Since I had a couple I used them. Works great on the K-55-G. Thanks for the response.

    I

    http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=170136957204&ssPageName=STRK:MEWN:IT&ih=007

  9. I've got some mid compression drivers that are 114db and the 12db attenuation of the T2A autoformer isn't enough to pad down to 96-97db. Can you connect two autoformers to get additional attenuation of 18db? Can you use a padding resistor with the autoformer and if so should it be placed after the autoformer? Thanks.

×
×
  • Create New...