moray james

I have tried to post the drawing and data on a Beck horn design but can't get it to drop into the post here so I have included a link to the original German site which you can translate with Google or Bable. The design is for a bass horn cabinet which while a little larger than a La Scalla (bass section 2'x2'x2') cabinet is much smoother in response (if the curve is real) and which extends out to 500Hz and down to 70Hz. I would be interested in any comment with respect to this horn design. I am thinking about using it along with subs and a pair of Nick McKinney unity horns. Any input or suggestions would be most welcome Thank you regards Moray James. http://www.egbeck.de/bec2.htm

Wuzzer: Thank you for letting me know this I had no idea. Can you explain how the term came about? My experience with biamping has been that going vertical makes less demands upon the amp running the low frequency drivers as opposed to a horizontal. I have also found that not all amps sound better when bridged. My appologies to Dennis. regards Moray James.

I hope that this picture has attache. Should be a silver on black Pie emblem. Looks very nice and reproductions will look very nice on my soon to be refinished Forte ll speakers. Regards Moray James.

That waas not necessary or nice and five way binding posts are cheap.

Test picture attachment.

Two additional things I did last night to my Forte ll. I tidied up the rats nest of wires inside by twisting up each drivers pair of lead wires. I also experimented with some diffraction in the mouth of each hor n I simply taped into place a stick of 7/16 inch dia. hot melt glue stick positioned vertically in the centre of each mouth of each horn. Results is better stage and image smoother more open sound. I think that a couple of small balls positioned inside the mouth of each horn would work better than the vertical stick. Easy to try and remove if you dont like it and easy to install something permanently if you decide that too. Have some fun. all the best Moray James.

I did not look up any info on your amp so I assume that it is a HT amp with multiple channels available. Must have at least four channels if you were able to bridge and still run two channel stereo. So you still have the ability to vertically biamp. Two channels right two channels left. This arrangement should sound better than simply bridging for more the power. No reason not to give it a try is there unless I am missing something? Best regards Moray James.

While you are in experimental mode why don't you try something else? With a little more speaker wire you might want to try a biamp set up rather than bridging. You shoud do what is called a vertical biamp set up . I assume you have two stereo amps so one amp per speaker right channel bass left channel mid/top and repeat on the second speaker with the second stereo amp. This should sound better than your bridged configuration. More separation and less bandwidth per amplifier. Have fun.Regards Moray James.

once you know the correct internal volume for your driver simply add bracing and stiffining till you use up the extra volume, bonus is a super solid cabinet with the volume you want. 2x4 braces on the rear panel sides and top will only help sound quality. making the box bigger is a harder trick to do. Regards Moray James.

Have responded and am still interested if you are. Please PM me with your decission. Regards Moray James.

If you still want to do this just let me know. Thanks Moray James.

parts express or MCM or your local electronics supply house digi-key google and you will find them. Moray James.

Yes I am good with that. I think it will be a good mate to the Karlson K-15 cabinet they are the same vintage and Jensens were one of the recommended speakers for the Karlson. Send me a PM with the details and we can get things going. I can send you the funds but it might be best shipped after the Christmas rush and crush? Thanks this will be fun I wonder if the alnicl could use a recharge after all these years guess I will find out. At any rate it won't be going to the land fill that's for sure. Best regards Moray James.

Regarding the Jensen: I have an empty Karlson K-15 cabinet which would be a great match for the Jensen. I think I can repair the cone. The best means of shipping would be USPS surface not ups please. I am in Calgary Alberta Canada T2V0H9 could you check at the post office for the amount and get back to me? Thank you. Best regards Moray James.

Last friday night I took the Forte ll's over to a friends place for him to use while he works on a set of ESS Heil AMT 1D's. We worked and listened and after some play with the position the Forte's got happy. I have to say that this being the first chance I had to listen to them with some horse power and they are great. First audition at the last owners home was on a Grant Fidelity 300 B set amp and they sounded very nice. This time was on a fully rebuilt Sansui AU-Dll Mkll at 130 watts per channel fully balanced and bridged amp with ultra low distortion. I have to say the stock Forte ll exceeded my expectations. As for the tweeter horn I really don't think I could justify the necessary work and cost involved and the possible miss match in switching them out. With the phenolic diaphragms they sound excellent, smooth open and they don't distract in any way. I will likely try a set of Bob's titanium domes after I upgrade the mid diaphragms with the new phenolics later this week. Reports here would indicate the titaniums (for the tweeters) sound excellent. As they stand now the tweeters in the stock condition don't sound like they need to be replaced. So it was an interesting time looking into all of this and I very much appreciate the assistance from the fine folks on this forum. I will buy a set of Bob's titaniums soon and try them out and report back as to my findings. As it stands I thank PWK for a job well done and I am most pleased to have joined a community such as this one. Best regards Moray James.

John: sorry to hear about your trouble. Please keep us advised as to how this plays out. I am sure there is a bright warm light at the end of this hopefully short tunnel. regards Moray James.

one of the forum members posted apicture of black pies with a smooth surface and silver trim. If I could figure how to post the picture on this forum I would but no such luck. I think these with holes would look beautiful. Please let me know if you can do these and what you would want for them.Thanks and best regards Moray James.

while you are in there flip the woofers 180 degrees. They have been in there a lot of years and the suspension will have sagged by now. By flipping them over gravity will pull them back to where they are supposed to be. Its a good idea to do every five years or so. Place a pencil mark on the centre of the driver at the bottom edge of the gasket befoer youu remove the speaker so you will know to place it to the top when you reinstall the speaker.

Thanks Wuzzer: for the information. I asked Klipsch about when the made the change from phenolic to poly in the tweeters. Their response is in blue below. I may just end up going with Bob's new titanium diaphragms for the tweeter, time will tell. Is there anybody who has measured the efficiency of the K61K and the K75K drivers? Bob said that 99 db ought to do for a replacement driver. If I change the tweeter it would make sense to use a horn with the same horizontal dispersion as the stock one. If I decide to stay with the stock tweeter horn then I could be loooking for a comp driver with very smooth response from about 4K to 20k and then deal with the level compensation in the crossover. Starts to turn into a project huh? I will continue looking for the time being but those BC Titanium diaphraqgms are looking better each day. The forte II actually used phenolic as the forte did, even though the web site says poly in the II Phenolic was used up to and maybe past the KG-5.5 as I have found phenolic in KG-5.5 factory tweeters Current replacement dia kits use poly. Phenolic suppliers have dwindled and poly dia offered tighter tolerances over phenolic.

Well that's the problem the fostex response graph is not exactly one which instills confidence. I can't do a measurement so I can't check it I can only listen. I had a set of the Fostex a few year back for another project and they were very smooth and did not draw attention in any way.I guess that I could look for some of the stock Forte Mk l tweeters and exchange the diaphragms but that seems like a project. The undercurrent seems to be that the stock tweeters are good. I just thought that better might be available by now. I have not seen any one inch exit comp drivers which are flat and extend to 20K for the tweter though I have found a couple of tweeters that look the part. Nor have I found any affordable one inch comp drivers that will extend low enough to replace the driver on the K61K mid horn. Are there any who have done any upgrade mods to the stock Klipsch compression drivers? If not I will have to leave well enough alone. Do any of you know which Klipsch horns use the same phenolic tweeter diaphragms as in the Forte l ? That way I can keep my eyes open for a set if they show up used and then be able to run phenolic diaphragms on both the mids and the tweeters.Regards Moray James.

Wondering if any of the members here have tried alternate compression drivers on a Forte ll mid horn If so which drivers and what were your results? I have been looking to see what is out there which might bring better results than the stock compression driver and I don't see anything at any kind of reasonable cost which will do the job. So I am now wondering if the stock units are better than I had given them credit for being? Has anybody here done any modifications to their factory drivers? I have a set of Bob C's new phenolic mid diaphragms on the way so this would be a good time to play if there is anything worth doing. Thanks for any input. Regards Moray James.

I was given the suggestion to have a look at some Fostex tweeters. The FT17H looks very good at 98.5 db efficient and with excellent extension way past 20K. If the response graph is accurate it is the smoothest tweeter that I have found so far.

Thanks DJK: I just saw that set of comparrison curves and that was my impression also. Several members had commented likewise. I spoke to Bob C yesterday about how to compensate for a new tweeter witha different efficiency from the stock K75K,. Bob suggested to use an auto transformer as the best way to adjust the tweeter level. So I am still thinking that the Beyma SMC2012/N would be an excellent replacement from a response point of view. It is one of the smoothest compression tweeter units I have yet found regardless of cost. The only issue is its tighter dispersion in the horizontal plane at 50 degrees. I wonder if this willl cause issues when the mid horn (at 90 degrees horizontal) crosses over to the Beyma at 50 degrees horizontal. Any coment regarding this would be most welcome. I suppose that with the Beyma SMC2012/N only costing about $70.00 each it might just be worth while to bite the bullet and get a set then try them out. I would expect it to sound excellent.Thanks for the help. Regards Moray James.

Have been doing my homework and found this so no curves though. Specifications FREQUENCY RESPONSE 32Hz-20kHz(+-)3dB POWER HANDLING 100 watts maximum continuous (500 watts peak) SENSITIVITY 99dB @ 1watt/1meter MAX ACOUSTIC OUTPUT 119dB SPL NOMINAL IMPEDANCE 8 ohms CROSSOVER FREQUENCY HF 7,000 Hz LF 650 Hz MAXIMUM ACOUSTIC OUTPUT 119dB SPL TWEETER K-75-K 1" (2.54cm) Polymer diaphragm compression driver HIGH FREQUENCY HORN 90(o)x40(o) Exponential Horn MIDRANGE K-61-K 1.5" (3.81cm) Phenolic diaphragm compression driver MID FREQUENCY HORN 90(o)x40(o) Tractrix® Horn WOOFER K-25-K 12" (30.48cm) Fiber-composite cone active / KD-15 15" (38.1cm) Fiber-composite cone passive ENCLOSURE MATERIAL Medium density fiberboard construction (MDF) ENCLOSURE TYPE Bass reflex via passive radiator DIMENSIONS 35.4" (89.92cm) x 16.5" (41.9cm) x 12.25" (31.1cm) WEIGHT 67 lbs. (30.42kg) FINISHES Walnut Oil, Oak Oil, Oak Clear, Finished Black BUILT FROM 1989 BUILT UNTIL 1996

DJK: thank you very much for catching me I really appreciate it. I have had the speakers all of two weeks and the previous owner told me the tweeter was a T35. I must admit to being very careless in that while I have had the grills off a half dozen times I did not stop to really look at the tweeters. I was much more interested in the mids as I was told they were very good. Do you have any links to data on the drivers and horns in the Forte ll? I have been looking and found a post which said the Forte ll tweeter is a K75K and the mid is a K61K is this correct? Is there info on these units curves efficiency and dispersion? I would be most interested to see the response of the K75K to see how it compares with the K77. If the forte ll tweeter is in the 101 db range that means that the Beyma SCM2012/N could be a good replacement choice. Thanks again for you help. Regards Moray James.