moray james

Just an observation as I do have a set of Forte ll but not the Chorus ll. If you take a look at the factory spec sheets for the two speakers you will see that the Chorus ll with its larger woofer has been crossed over to the mid Tractrix horn at 50 Hz. lower than the Forte ll is crossed. The reason for this is simple the Chorus ll fifteen inch woofer is going to have disperssion issues much lower in frequency than the twelve inch woofer of the Forte ll. That means you are asking the exact same mid driver and horn to run a full 50 Hz. lower in the Chorus ll than in the Forte ll. The mid is already running very low in the forte ll and an extra 50 Hz is a significant request. Remember the filters don't chop things off and drop like a rock they roll slowly. I would fully expect that the Forte ll will have both lower mid range distortion as a result especially so at high levels and better (smoother) disperssion than does the Chorus ll. Trade off is the Chorus probably has a little more jump and at hi level the Chorus ll's fifteen inch woofer is probably a little cleaner since excurssion will be lower for a given level when compared to a twelve inch woofer. At normal loud listening levels 90 -100 db both probably sound equally as clean with the overall edge going to the Forte ll in terms of spatial image and detail. I think that in a side by side anybody who is sensitive to spatial detail image and sound stage location would probably give the nod to the Forte ll but if you were not doing a side by side both would sound fine. If it were not for the size I would be tempted to go with the Chorus to get the extra dollop of wallop it can provide. There is also another thing I forgot to mention and that is the passive size The Forte ll has the benefit of a fifteen inch passive which will provide better control and be more linear at level than the Chorus ll with a fifteen inch passive. They are both great speakers just depends upon what your preferences are. Now a supersized Forte lll with two twelve inch woofers per cabinet perhaps in a push pull slot loaded reflex would be killer. Regards Moray James.

Why not check with Bob Crites and ask for his suggestion. I have found data that a K-23 is a 4 ohm driver with inductance of 1 mH and a K-24 is an 8 ohm driver with inductance of 1 mH both have about the same efficiency but Qt values are different for the two drivers. K-23 Qt = 0.226 and K-24 Qt = 0.323. The K-24 will definately work in your Forte but as to the exact difference you will hear I can't say. Regards Moray James.

well we may be going at it here at crossed purposes. I got the impression that you were interested in changing the crossover to accomodate a different woofer. An 8 ohm woofer will have twice the voice coil length as a 4 ohm voice coil will and that means an 8 ohm version will have greater inductance (probably close to double). So my suggestion to adjust the crossover inductor in the bass section of the crossover. If however you are asking for upgrades in general for the crossover then new capacitors of higher quality and also possibly new auto transformers for the mid horn. Non inductive resistors are also sometimes installed in the crossover. Bob Crites sells these and there are also other vendors who sell upgraded parts as well. Sorry if there was a missunderstanding hope this helps. Regards Moray James.

You can check to see which speaker uses the K-24 and then check for the crossover to get the right inductor value. Regards Moray James.

I am not a crossover designer so please this is just a suggestion. I would think that you would need to measure the inductance of both the voice coil in a K23 and a K24 and adjust the inductor value in the bass section of the crossover. That would be a good start as the crossover frequency would be maintained. If there are significant differences in the two drivers response that might have to be taken into account. You can purcharse woofers for your Forte from Bob Crites and not have to play with the crossovers. Regards Moray James.

Hey sorry if I was in error. All the photos that I have seen of the inside of Cornwal's have had the thin pads inside on the walls. The Cornwall is a vented cabinet and only three inside walls with damping is enough to damp internal reflections and the main cavity of the cabinet is left open and the vent then takes care of (damps) the primary driver / cabinet resonance. With closed boxes stuffing is usually evenly dispersed throughout the cavity and the amount will depend upon the driver used. Theory says you can achieve as much as 30 - 40% of increased cabinet volume by stuffing but it is not normally that high a percent in practice. Has anybody gor any pictures of the iside of a Cornwall ll? Regards Moray James.

Klipsch does use damping in the Cornwall speaker. It looks like a paper lined material but it is damping. if your cabinets are just bare wood inside then this damping has been removed by someone. With a well designed reflex cabinet you don't need or want volume damping as might be seen in a closed box design. The old three side coverage is good to get the job done. You are only interested in damping internal reflections and your horns will also help to break things up. The main bulk of the cavity must be free to resonate so the reflex vent can become energized and do its job of damping the cabinet volume. This may sound counter intuitive but you have to have one resonating volume to excite another. So do not stuff your cabinets as that will prevent the reflex vent from functioning properly. When a driver is damped correctly excessive and unwanted motion is eliminated so it is easy to see why mid range operation will improve. Hope this helps. regards Moray James.

Dennis; do you know if any of the pro horn makers provide the throat angle of their horns? It would seem logical to want to match driver exit angle with the horn throat angle to minimize reflections. This is not something I have seen but I may not be looking in the right places or asking with the right terminology. Thanks for any light you might shed on this. Nice looking horn by the way, I think that 18 Sound also have some ellipictal horns similar to this as well.regards Moray James.

Welcome and congratulations on the new to you Forte speakers. I recently got a set of Forte ll speakers myself and am impressed with them. I decided to go the route of upgrade first and found that they are a very good speaker right from the factory. There are some good options to take as far as upgrades go though. New crossovers are a wise ides given you have Forte l's and the caps in the stock networks are all getting old. Al Klappenberger of ALK Engineering has a fully redesigned crossover (for the Forte l) available as a kit or you can download the schematic and build it for yourself. Al's new circuit deals with a number of issues left undone at the factory and the net result is a more uniform impedance curve which make any amp happier. Next on the list are new diaphragms for your horns. Bob Crites has new upgraded phenolic diaphragms for the mid horns and new Titanium diaphragms for the tweeters and Klipsch has a new Titanium diaphragm for the mid horns. There are a number of posts here discussing the benefits of these parts that you can look into. A simple thing which I did with my Forte ll as a stopgap to new custom made harnesses for inside the speakers was to sort out the internal wire sets from the crossover and twist each of the pairs. Check to see your cabinets are air tight (cover the holes drilled for the magnetic grill inserts) and install new driver gaskets (flip your woofers 180 degrees) and make sure the passive has a sound leak free suspension. The passives can often get damaged with no cover when they are moved about. I found a few small holes in one of my passive suspension and fixed it with some adhesive good as new. A buddy of mine just got a Sansui AUD 11 Mkll which he restored and modified extensively including installing a mosfet output stage. This is a fully balanced bridged amp and it sounds wonderful with amazingly low distortion being balanced and bridged it does not get any lower. The amp (even stock) is stunningly good and makes the Forte sing with a good source. I have never been a receiver guy so I cannot give you any good leads there. There is a lot that can be done by way of upgrades to many amps but old receivers and intigrated units are a lot of work and have many age related issues and so often get left behing as a result. My friend rebuilt and modified a Luxman L480 this past summer and also switched out the transistor output for a mosfet one and it is a beautiful sounding amp but again a lot of work. A old Hafler 200 or 220 can be more easily worked on and turned into a fine modern day sota amp but only if you want to go that direction. Just thought I would add a different perspective to give you some alternate angles to consider. Even though the Forte are efficient they really do seem to like the control that haveing some horse power brings. I am sure that they can also sound excellent with some small tube amps. I have an Antique Sound Labs Tulip which is very modified and which is a 2A3 stereo amp that has excellent bass. I have yet to have the chance to run my Forte with this 3.5 watt beast but I am expecting that the combination will be very good. Lots of way to skin a cat as they say. All the best to you and I think that you will find that you have come to the right place. So many great people here in this audio family with incredible experience. PWK sure did a fine job on the Forte. Regards Moray James.

Hello: if you could post some pictures of the damaged passive and your broken terminals that would help. Tears in your paper cones can easily be repared with some white or yellow wood glue. Use just enough to wet the edges of the tear. A small piece of masking tape on the back side of the cone to hold everything in place while the glue set will keep things looking neat from the outside. wood glue will set in 30 minutes. As for your comment of cones being slightly pushed in on both you are going to have to be more specific. I don't know if you are referring to the dust caps of the bass drivers (on the front of the cabinet). Dented dust caps on the rear passive radiators will have zero effect on the performance of the passive so unless you are concerned with the visual effect just ignor any dents there. With respect to the mid range driver, remove it from the cabinet and check the wiring is connected. If that is ok then remove the driver (make note of the wire polarity) and test the VC of the horn with a household battery 1.5 or 9 volt is fine. with a couple of small wires connect the battery to the leads on the mid driver (polarity does not matter). If you hear a noise from the speaker when you connect the battery the voice coil is likely fine and the issue is either in the wiring or the crossover. Start with the above and see how things go and do try to post a few pictures. I am sure that someone here can help you to get back up and running. If the mid problems turns out to be a dead voice coil (not all that likely) then you would have to buy a new set of diaphragms from Bob Crites. You can no longer buy new replacements of the stock diaphragms in your mids so a new matched set will be required. Let us know how this goes. Regards Moray James.

Al: I have been interested to learn what kind of difference it makes to match the initial throat geometry of the horn to the exit angle of the compression driver in use. Seems that matching the angles would go a long way to eliminate horn throat related reflections back into the driver. Of course there can also be some reflections in the horn and from the mouth of the horm as well. Less reflections should be the desired goal. Have you read anything about this? Manufacturers don't seem to address this in their literature. It would seem a little self serving of manufacturers to lead consumers to think that a given comp driver could be mated up with any available fitting horn but as we know some combinations work better together. If we assume that loading of the comp driver is fairly consistant from one good horn design to another then geometric related reflections might be the primary source of sonic differences and performance between different driver/horn combinations. This is likely a very simplistic appraisal of the situation but it would seem to be worth discussion. regards Moray James.

Thanks for the additional info as to what you had tried out Re the mid diaphragms. I would be interested in hearing from those who have installed Bob's new phenolic diaphragms and learn how long they found the burn in process to be. Given such high efficiency drivers I would imagine weeks to months depending upon your listening level preference. I too am interested in the Tittanium diaphragms but burn in time has to be accounted for. Phenolic diaphragms should have far greater internal loss when compared to Titanium and would I imagine have a more polite and progressive onset of breakup distortion. Regards Moray James.

Sorry but I am a little confused. You started with stock Klipsch phenolic mid diaphragms? Then you bought a set of Bob C's new mid diaphragms which are also phenolic and it sounds like you like them better than the stock phenolics? Is that correct? Then you mentioned that the Ti diaphragms were more transparent and natural. So this is where I get lost. Did you also buy as new set of the Klipsch Titanium mid diaphragms? So which diaphragm is it that you like best? Thanks for making this all clear. Regards Moray James.

what about using the KHorn network and mid/tweet then turning the cornwall around and firing it tight into the corner (running just the woofer)? you might also want to experiment with the polarity of the cornwall woofer. just a thought.

You might be interested in checking out a"Stretch Heresy" designed and built by Dave Harris of this forum. You can see this project and numerous others at Dave's home page. Regards Moray James. http://mysite.verizon.net/res12il11/id76.html

There are a number of threads on Onken style cabinets over at DIY audio and GM is a wealth of design information on speaker. Dave at planet 10 hifi has also designed a number of Onken style cabinets. Please let up know how this works out. Would look very cool for your stretch Heresy. Best regards Moray James.

Just my 2 cents worth here. The pipe is acting as a reflector or deflector of the back wave off the driver directing it to the side Onken style reflex vents. As such this seems like a good idea but you will likely find that this reflects upper range frequencies from the driver (which you want to be absorbed by internal cabinet damping) out into the vents. That means that you will now have two closely situated sources for these sounds (direct from the driver and secondary from the vents). Such issues cause confussion to your brain which is then trying to localize the image with multiple physical sources of the same sound. I suppose you could experiment with multiple internal drapes of 1/16 inch wool felt directly behind the driver to reduce the midrange energy output off the back side of the driver to help minimize this. You could also experiment with wool felt pads on the surface of the tube as well. The Onken is a modified reflex design and like all reflex designs the vent is tuned to resonate in antiphase at the cabinet resonant frequency, this then loads the driver and provides acoustic control right where the driver lacks the ability to do so itself. I am not sure if the reflector (pipe) is going to help matters in any way. I would think that an internal cabinet design which provided smooth non turbulent air transfer from the vents into the box and back out would be the most productive measure to undertake regardless of what kind of reflex cabinet design you are looking at. Onken style cabinets can sound very good but they are not unlike any other cabinet in that they must be well designed for the intended driver to perform their best. Regards Moray James.

Al Klapenberger is working on a crossover for a new 2 inch entry KHorn mid horn which incoroprates a coaxially mounted mid/hi compression driver. You might ask Al if this could be made to work with a Chorus. That might get you what you are looking for. Check out this link. Have some fun and good luck. http://community.klipsch.com/forums/t/142399.aspx PS: just a thought but why don't you first consider new crossovers and diaphragms (upgrades) for mid and tweeters first as that could well deliver what it is you are looking to achieve.

The Cambridge Audio Azur 650A is a very good sounding amplifire and hard to beat at the price point, in fact I like it better than their larger more expensive models. One of these use ought to do a very good job of driving your Forte ll. They have a slightly lower power version the 550A which has a front docking station but I am not sure if it has any digital inputs (I kind of doubt it though). All in all the 650A is a very good Doug Self design which ought to impress. Good luck.Best regards Moray James. PS if you were willing to go the used and upgrade route a Luxman L 480 modified to have a mosfet output stage by John Wright of Museatex is a superb sounding unit with a great phono stage as a bonus.

Why don't you consider building a set of Cornscalla's with a Fastrack mid horn? Regards Moray James. //mysite.verizon.net/res12il11/id89.html

Well it's pig in a poke but it could be worth your time, cross your fingers and don't go if you are going to be upset if it's a bust. Enjoy the drive and if it is a good deal please don't grind the guy for a discount as he will be loosing enough as it is. Good luck and post some pics either way we deserve to hear how it all goes. Regards Moray James.

When I first opened my Forte ll I found a rats nest of parallel wires. I straighened out the bundle and twisted each of the pairs of the driver wires. A twisted pair will sound better and will minimize RF pick up of the cable. Why don't you try this first and see if you like what you hear? If you want you can bump the gage to say 14 gage and twist those wires as well. going much larger than 14 gage is just going to become problematic with respect to the install. Your house wire is 14 gage solid core and is good for 15 amps. That's more than you are going to pump into your Heresy speakers.You will probably have to cut off enough strands on the 14 gage set (at the crossover board end) to insure that they will comfortably fit into the holes on your circuit board. Don't worry about this increasing the DCR of the wires as it is only for a very short distance and will have almost no effect on DCR. I am not sure I understand what you are referring to with respect to seeing resistance and then suggesting to use half the wire (size) to the mid and tweeter? You should use the same gage wire to each of the drivers. You could use your left over speaker wire but the jacket is just not necessary for an internal install like this. Use crimp on connectors at the drivers like you have now, you can solder the crimps if you like just make sure you don't run solder into the connectors. Use a bare copper stranded wire, PVC insulation is fine. The finer the strands of the wire the more flexible the wire will be. You don't have to go nuts here standard hook up wire in the gage you want is fine just twist it into pairs. Hope that this helps. Best regards Moray James.

Give the Adcom as many constant on hours as you can (three days should get you going) and listn again and don't hesitate to play with the position of your speakers with the new amp. That way you will have given the Adcoma fair shake. Regards Moray James.

Thanks for your input. I have been considering a distributed sub bottom end with four or five 6.5 inch TB bass drivers in quite compact tapped horn cabinets. The idea with the Beck horn was to get smoother response out to the crossover point of the Unity horn (370 Hz.) than would be possible with the La Scalla cabinet. Not having heard the Beck is of course a bit of a problem but the response does look promissing and the layout looks to be well thought out.The KP-480 goes lower than either the La Scalla or the Beck but not up to the Unity so an additional cabinet gets thrown into the mix. Regards Moray James.

Wuzzer: last weekend I took my Forte ll over to a friends while he was working on his speakers so the system was open. We started with the Forte in about the same position as his ESS Heil AMT1D's (well into the room) as both speakers have rear mounted passive radiarors. This just did not work for the Fortell. Over some time I worked the speakers toward the front wall spaceing them wider apart as I got closer to the wall. In the end they were about 11 -12 feet apart and toed in about 8 -10 degrees perhaps only an inch off the wall and that seemed to work. Seating position about 10 feet back from the speakers. A little later I started to increase the toe in but while the image got better there was additional edge or hardness being directly on axis. So I got four hot melt glue sticks which were handy and about 7/16" dia. and some scotch tape. I used the tape to position the glue sticks in position vertically across the centre of each horn. the idea was to use the sticks as makeshift diffractors to deflect the on axix output of the horns diaphragms off toward the side wall. With this simple set of diffractors taped into place the stage and image got wider deeprt taller and the whole sound stage dropped back. Music was smoother and seemingly more extended at the top a little. The speakers did a better job of disapearing. I think that positioning a couple of small balls in the mouths of the two horns would work better than the vertical sticks. You might want to give this a try with some dowel or perhaps just some marker pens or the like to see if you experience the same thing. The diffraction stick or device as it may be does not change the output of the horn in any way as most of the horns output just blows on by but the nasty stuff from the diaphragms gets knocked off toward the side walls and then has to bounce to get back to the listening position. The time delay envolved lets your brain recognize the sound as part of the music but sees it as a reflection and so can more easiy ignore it. Give it a whirl and tell me what you think. I like these speakers quite a bit and think they have a lot of potential. I just got new mid diaphragms from Bob C and may also get the tweeter diaphragms as well. I plan to rebuild the crossovers probably in the new year. Best regards Moray James.