jwgorman Posted January 26, 2019 Author Share Posted January 26, 2019 What frequency are you crossing at? Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted January 26, 2019 Share Posted January 26, 2019 800 Hz. on my AMT 1D's (by ESS)..............but it depends on the slope and the woofer you use with it. You can go 1200 with a 12" or about 900 with a 15". You don't want to overdrive the low end too much, so higher order is better, like 24 db/oct Linkwitz-Riley if you are active with a 15.. Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted January 26, 2019 Share Posted January 26, 2019 On 1/4/2019 at 8:00 AM, Chris A said: I'm using an ElectroVoice Dx38 (DSP) crossover connected to two stereo amplifiers--a Crown D-75A for powering the woofer channels, and a ICEpower 50w amplifier for the AMT-1s-- whose outputs are directly connected to the woofer (one channel for each woofer) and AMT-1 (one channel for each AMT-1). That's how I'm able to EQ the loudspeakers to flat response, the parametric EQ filters of which are shown above. If you were going to use passive crossovers and mono-amplify each, you could use only an inductor in series on the Cornwall woofer, and a capacitor on the AMT-1 channel, whose values each are shown below. Then you could use upstream parametric EQ somewhere in the signal chain to re-EQ each loudspeaker using values similar to the values shown in the above. Chris Do you have to use a buffer board for your ICE power or your drive good enough without it? Quote Link to comment Share on other sites More sharing options...
Chris A Posted January 26, 2019 Share Posted January 26, 2019 No buffer--directly driven from the crossover. 1 Quote Link to comment Share on other sites More sharing options...
jwgorman Posted January 26, 2019 Author Share Posted January 26, 2019 On 1/24/2019 at 12:26 AM, consistent said: UPDATE I have been fooling around with various xover networks and have found, to my ears at least, that a 2nd order Bessel with a Zobel across the woofer works best, if fact it opens up the AMT and helps it blend better with the woofer (Crites woofer). Still you may need to move the AMT around the top of the Corn box to get the best alignment for you room. It is an amazing combination all the best Ok, 800hz 2nd Bessel. I have a box of inductors and caps and it’s way too cold to play outside today. Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted January 28, 2019 Share Posted January 28, 2019 On 1/26/2019 at 11:05 AM, jwgorman said: Ok, 800hz 2nd Bessel. I have a box of inductors and caps and it’s way too cold to play outside today. Oh, come on. Where is your sense of adventure? Quote Link to comment Share on other sites More sharing options...
windashine Posted January 28, 2019 Share Posted January 28, 2019 Quote Link to comment Share on other sites More sharing options...
jwgorman Posted January 28, 2019 Author Share Posted January 28, 2019 12 hours ago, ClaudeJ1 said: Oh, come on. Where is your sense of adventure? I’m still searching for it! Quote Link to comment Share on other sites More sharing options...
consistent Posted January 31, 2019 Share Posted January 31, 2019 you can go with a LWR @ 800 (+/- 100hz) but to me in my room the Bessel is a good fit. BTW I am using the same clarity caps and the coil...scary!! Quote Link to comment Share on other sites More sharing options...
windashine Posted February 7, 2019 Share Posted February 7, 2019 i'm still here.... this is just an update from a slow hand, a piece at a time, tomorrow I get a day off to trim the motoboard and assemble the port shelf... plus a brace before I glue and clamp together, square... Quote Link to comment Share on other sites More sharing options...
No.4 Posted February 8, 2019 Share Posted February 8, 2019 22 hours ago, windashine said: i'm still here.... this is just an update from a slow hand, a piece at a time, tomorrow I get a day off to trim the motoboard and assemble the port shelf... plus a brace before I glue and clamp together, square... Nice! Looking forward to the finished product. I am planning on something similar with my Heils. I may play with the dimensions but keep the internal volume the same though. 1 Quote Link to comment Share on other sites More sharing options...
consistent Posted February 11, 2019 Share Posted February 11, 2019 looking good,...what internal volume are you using and what ports will you try? Quote Link to comment Share on other sites More sharing options...
windashine Posted February 11, 2019 Share Posted February 11, 2019 10 hours ago, consistent said: looking good,...what internal volume are you using and what ports will you try? … o O (if that question is to me, I'll jump in) ... internal volume = currently unknown, but hopefully "spot on" the CW 1.5 spec ... ports = 3 rectangles cut 2 and 3/16" x 6 and 7/8" into the bottom of the 34 and 1/4" x 23 and 7/8" motorboard under a nine & half inch shelf sitting on 2 and 3/8" supports glued three and 1/8" off the floor, with 3/4" x 3/4" notches cut into the front edges, and... with the 15" cast frame Crites woofer (to be) as close to the top of the cabinet as possible.... with no mid or HF cut-outs involved... thoughts = quite a range of more unknowns, so like 1 could be a wooden closet rod in the middle of the inside of the cabinet for a brace or a 45 degree mid mounted shelf with holes drilled in it, to make a "cattle rustler" lol for the back pressure undecided about drilling a hole in the top of the cabinet to make a wire to the AMT-1 (which just make's me think of a new crossover idea) which I won't type because it seems embarrassing, however, it doesn't matter until I try it, which could resemble a thought about a double spade connector on the back door.... Quote Link to comment Share on other sites More sharing options...
consistent Posted February 12, 2019 Share Posted February 12, 2019 Bobby Crites has some good specs on volumes, seems as though there is some difference between boxes over the years. Guess it's about what goes inside the box and what does not! Then this will dictate how you can strengthen the box like Roger Floth suggests as do a few others. To match the AMT-1 I think the tighter the sound coming from the box the better the resolution between the two drivers. good luck 1 Quote Link to comment Share on other sites More sharing options...
windashine Posted February 12, 2019 Share Posted February 12, 2019 Thanks, I realized I had R Floth's "Equalizing the Cornwall" already, after reading some info this morning... I think one way to use my philosophical approach here, is having these "lifesavers" handy...( to use afterwards when needed)... but in essence, this listening experience from another point of view is building with wood and adding braces to feel the improvements over time... my goal is not necessarily the lowest bass on earth, but the cleanest reproduction... a sturdy cabinet worthy of dreadnoughts' scalloped bracing with Jimi Hendrix's finest intermixed with how simple capacitors and Air Motion Transducer's reflect... Quote Link to comment Share on other sites More sharing options...
Chris A Posted February 12, 2019 Share Posted February 12, 2019 A pdf of that Roger Floth article on "Equalizing the Klipsch Cornwall" from March 1989 of Speaker Builder (which you cannot find elsewhere nowadays) can be found here: https://community.klipsch.com/applications/core/interface/file/attachment.php?id=79774 Thanks again to Gil for assembling and posting it in this thread: Chris 1 Quote Link to comment Share on other sites More sharing options...
consistent Posted February 14, 2019 Share Posted February 14, 2019 cheers...I did the Floth method and the bottom end did tighten up and go deeper. It is important to choose a xover network to go with this approach, it's not easy Quote Link to comment Share on other sites More sharing options...
windashine Posted February 19, 2019 Share Posted February 19, 2019 update on chasing the AMT sound by a diy approach... I modified a plunge router circle cutting jig to hold an older craftsman... drilled a hole on the inside edge of my pencil mark on the motorboard, to start the router, and made about 5 cut's,,, going about an 1/8" deep each revolution... I made the final cut using a 6 5/8" radius at full depth, for a 13 1/4" cut-out, going into the foam board underneath. One thing I did was screw down the cut out piece to my table to hold the pivot point stationary, and clamp the outer edges of the motorboard, to hold the board from moving. This coming Friday, I'm going for the port's on the other end of the motorboard.... thinking about leaving the center cut out of the project, due to the philosophy of the Roger Floth article (where he blocks the middle) and just installing the port shelf with the other three blocks attached with screws. Have to make a decent jig again to control the router path lol..... cheer's Quote Link to comment Share on other sites More sharing options...
windashine Posted March 5, 2019 Share Posted March 5, 2019 Bump for a Build Continuation... Got a new Compact Router today... Built a jig to assist in the port cut-out's.... (just slid and measured, clamped and screwed tight, cut a shallow 1/4", then a 1/2" deep, then 3/4" thru).. Plan to start out with the stock CW port shelf, but just attach it with 2 screws on each side block, maybe add Roger Floth's concept in the future, because it's off the AMT thread and I'd be guessing for a capacitor to use... but then... a low priced ice power amp seems inevitable, and maybe before I find a Nelson Pass Pre-amp ... o O (alway's wishing) nothing is sanded yet, still thinking about a cabinet brace too, just wanted to post before I "pop a top" lol … incase nobody has seen an inverted Cornwall Motorboard without the Mid and HF cut-out's... I put the 13 1/4" speaker cut-out where a stock speaker would off been when flipped, so I'd had flutter if I'm doing something wrong, I guess)… it could of been about 2 or 3 inches higher... but when next to my old '54 Klipschorn, it's right about in the same spot, off the floor... Quote Link to comment Share on other sites More sharing options...
windashine Posted March 5, 2019 Share Posted March 5, 2019 1 Quote Link to comment Share on other sites More sharing options...
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