Khorn mod project - need driver info

[rplace]

I think I am going to have a bit more free time in the near future so I want to get all my parts in place before I start.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

I want to build a test top section for my Khorns. If I am happy with my results I plan to build a top section that looks pretty much like a standard khorn, but just a bit taller. Inside will be 511b horns with Bob C's tweeters centered above the mid horn. I will construct the top section such that the Mids/highs can be twisted or pivoted a bit inside the outer skeleton that closely resembles a stock khorn. I had considered decorator sort of look for the top section, but decided against it.

I don't want to modify my current HF section so I can put them back to stock at any time.

I also want to minimize the time between switching back and forth. For this reason I want to get a 2nd set of matching mid drivers so I can simply remove the wires from the drivers and swap them out.

I am currently running DeanG's ALK Jrs for networks. These are 1987 Khorns, they have the 400 horn not the 401 horn. Originally they had AK-2 networks. I have not looked at them for a while, but believe they have K-55M drivers.

Already have the 511b horns and Crites tweeters; also have Selenium adaptors from parts express to put the Klipsch mid drivers on the 511b horns

Questions:
1. Since I need a 2nd set of drivers and want to do an accurate comparison do K-55M drivers sound like the right ones? If not what would be the correct drivers for that year? I know this is a transition period and other have though I should have 401 horns. I see a few K55-Ms on ebay are there any difference between them like there is for the Vs with phase plugs or will any old M do the job?

2. Will I have any issues with regard to my networks switching between the current stock set up and my proposed 511b/k55/Bob's tweets?

3. Do I need any other parts?

4. Anybody done this sort of thing (External structure looking like khorn top, but "aim-able" guts) and care to share thoughts or suggestion?

5. Anything I am forgetting?

[rplace]

Wow, 21 hours and no opinions or thoughts. That is rare from this crowd.[]<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

How about the driver info? I see a pair of k-55Ms on ebay. They are said to be 16 ohms. Arent they typically 8 ohms, or is that the speakers as a whole showing 8 ohms to the amp, but the individual drivers will be different? In case you have not noticed I am not all that well versed in the inner workings of speakers.

[Deang]

...I need a 2nd set of drivers and want to do an accurate comparison do K-55M drivers sound like the right ones? If not what would be the correct drivers for that year?

If your Klipschorns came with AK-2 networks, then I'm pretty sure they also came with the K-55-M drivers. I guess the most obvious distinguishing visual cue is the flat, black plastic cap on the back.

"...are there any difference between them like there is for the Vs with phase plugs or will any old M do the job?"

They are all the same, and they are all 16 ohm drivers.

"Will I have any issues with regard to my networks switching between the current stock set up and my proposed 511b/k55/Bob's tweets?"

None at all. In fact, I think you'll find Bob's tweeters a better match with the network I build. Since you have the ability to dial down the squawker -- you're O.K. here too.

Do I need any other parts?

The adapter so you can mount the drivers to the 511's.

"Anybody done this sort of thing (External structure looking like khorn top, but "aim-able" guts) and care to share thoughts or suggestion?"

Don't know, most do it with false corners. Don't forget that you will have to change the shape of your new top hat so you can turn it. That is, you can't really use the home plate shape anymore.

[rplace]

Don't forget that you will have to change the shape of your new top hat so you can turn it. That is, you can't really use the home plate shape anymore.

Dean, Thanks for the 16 ohm info. My mid driver for sure are flat sliver on the back with a black band around them. Not the rounded blue-gray type...pretty sure K-55M. Need to pull them from the corners to be sure.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

Hard to explain what I am thinking about for the inside aim-able part, but I will give it a shot.

Envision a home plate tucked into the corners like a standard khorn. Now imagine that the grill cloth or baffle on the front and sides can be pulled off leaving the home plate on top supported by the wood that is behind the baffle on the sides. Now you are looking at the 511b and tweeter on some sort of pivotable motor board. I aim it where sounds best and put the baffle back on. I am thinking this will give me a stock khorn look with the same functionality as unbolting the top had section and aiming it where you want it.

So the baffle supports the grill cloth only and the mid/tweet contraption is what I need to work on that will fit behind it. My contraption will need to sit slightly further back, but the 511b is not a deep as the 400. I don't need much "toe out" to accomplish what I want.

Perhaps I can't do it and I end up with two sets of standard top hats that have a full complement of driver and horns. At the very least I will have a quick way to compare a 400/k77 set up with a 5llb/Bob C set up.

[PrestonTom]

Re: the "aimable" top hat.

I seem to recall a thread a year or so ago where the guy designed a structure inside the top hat that could pivot a slight amount. The "outside" of the top hat remained in a fixed position so that it looked normal but the motor board could be moved. As I recall this required that the grill cloth was attached to a "cage" rather than the motorboard.

I have not had success in searching for this....

-Tom

[rplace]

Tom, I think we are on the same page here. The grill cloth would be attached to a sort of "cage" or "frame" that is held in place by friction between the home plate top and the bottom of the top hat. I thnk I remember seeing a picture of D-Dee's tweeter sitting in that open void behind a grill cloth-ed frame.

Pulling out that frame would give you access to the mid/tweet "thing" that could pivot. This thing would be a motor bord with the two horns mounted to it and what ever else is needed to support the back of the horn and allow it to pivot.

That gets me to thinking that one thing I need is grill cloth fabric. Who out there has some to sell me? Just need enought to make two slightly taller khorn fronts and sides.

[Deang]

There are some very high quality Lazy Susan type deals available, and when I looked into this a couple of years ago I found a couple with locking mechanisms.

[Guest " "]

""Wow, 21 hours and no opinions or thoughts. That is rare from this crowd.""

I was on the road all day yesterday. My eye's are still spining. When they stop spining, i'll look thru the thread and see if there is anything not covered already by others.

[rplace]

There are some very high quality Lazy Susan type deals available, and when I looked into this a couple of years ago I found a couple with locking mechanisms.

That is interesting...got any info/links on this?

EDIT: I found this http://www.rockler.com/product.cfm?page=2273 for TVs. Not locking.

[Jim E]

I am willing to lay the assembly out but I will need measurements on your proposed drivers and adapters. I will also need the correct measurements of your Klipschorn top cover.

I personally would prefer to use Altec 802-16G or 902-16A or B drivers on that 511 horn.

Jim

[George Roland]

I am very interested in what you are planning because I will probably be doing something very similar myself at some point in the future. My listening room is narrow and rotation of the upper section of my K-horns into the center of the listening area improves coverage a lot. I hope you will post lots of photos of what you build and what your finished work looks like.

George

[rplace]

I am willing to lay the assembly out but I will need measurements on your proposed drivers and adapters. I will also need the correct measurements of your Klipschorn top cover.

I personally would prefer to use Altec 802-16G or 902-16A or B drivers on that 511 horn.

Jim

Jim, thanks so much for that generous offer. I would surely like to take you up on that. I measured my drivers and they are 2 inches deep (attachment from horn to back of driver) they are also 4.5 inches across at the widest point (back of driver).<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

The parts express Selenium adaptor adds another 1.25 inches to the overall combined horn/driver length.

It looks like you have the 511b dimensions. I will get you my khorn "home plate" looking top piece dimensions if you need them, but they are the standard "B" style khorns. Anybody have those already? I am not near mine.

[3dzapper]

Rplace, What you are describing is what I did inside my stock top-hats except that I have trachorns and a seperate tweeter enclosure.

Rick

[rplace]

Rplace, What you are describing is what I did inside my stock top-hats except that I have trachorns and a seperate tweeter enclosure.

Rick

Rick, That is exactly what I was thinking about for my grill to cover up my pivotable innards! My aging memory must be failing...I thought it was a Daddy Dee pic, but I remember your wooden horn.

Do you "aim" your horns inside there at all?

My plan is to build the top portion taller so I can put my tweeter above the mid horn.

What did you use for grill cloth?

[3dzapper]

Dee may well be using a similiar set up.

I aim them ever so slightly. My couch is at nearly the perfect location as my room is just 13' wide and the horns about 22' apart. A different room or short wall placement would dictate where the horns would be aimed.

Try the tweeter in all four positions horizontally and vertically before you commit would be my advice. Especially with the 511s, you are reaching "new heights" with the tweeter. For a while until I put the trachorns in, I ran the tweeters on top of the Khorns. That is about where they would be in your plan. The dispersion of the 2404s and CT125s is different though.

In the pic that is just inexpensive Parts Express grill cloth. I have yet to order the correct kind. When I do, I need to build or recover the side panels. I just haven't gotten a round "tuit" yet.

Rick

[rplace]

Try the tweeter in all four positions horizontally and vertically before you commit would be my advice. Especially with the 511s, you are reaching "new heights" with the tweeter. For a while until I put the trachorns in, I ran the tweeters on top of the Khorns. That is about where they would be in your plan. The dispersion of the 2404s and CT125s is different though.

My plan was to actually build some sort of test motor board where I could test the tweeter inside and outside the 511b vertically and above it horizontally (K77s as well as Bob's). Then pick the best sounding location before building my final "pretty" version. I figure there must be a reason most 3 way speakers are set up with the tweets centered horizontally...but maybe that is just convention. I actually posted a message in another person's thread asking the question if given the option if should you mount it above the mid or to the side...I never saw a response.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

[D-MAN]

Sounds suspiciously like my setup...

DM

[Jim E]

I'm reasonably sure the convention of the "center alignment of drivers" is to improve the localization of the speaker. While two or three way systems are not technically point source speakers, stereo imageing is still important and offsetting drivers side to side would cause a bit of smearing. You could correct this with time delays but you would be locked in on your listening position and the cost of a three way electronic crossover, additional amplification and wiring is no small concern.

As a note though, bi-amping and/or tri-amping with time delays will give you a huge bang for the buck. I have been bi-amping my systems for almost thirty years and it's worth every cent. It is amazing how well our hearing can detect small changes in the direction and timing of sound. I guess it came in rather handy when we were hunters and prey.[]

Certainly try several mounting positions and listen to the setup before you commit. I would suggest using string instrument source material. I my opinion, the tweet does look sweet mounted to the side.

[rplace]

Sounds suspiciously like my setup...

You know the saying...Great minds think alike and idiots seldom differ.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

I was surprised to not hear some input from others on this matter. I thought surely I could not have been the first to consider this. With the search not working I have not had much luck finding out what others had done. I do remember posts about unbolting your top section, but I could not live with the look of it moved forward and turned.

D-Man, hard to tell from the pic, do you just have the mid/tweet sitting on a piece of wood to get the right elevation and point it where you want it? If so any problems with vibration? I was thinking I needed a more substantial contraption to mount the mid/tweet to and in turn secure it to the LF section.

I also have not given up totally on a decorator look for this proposed top section. This would put the "lips" of the 511b out in front of the forward plane of the speaker and in turn give me more degrees to pivot.

On a B or C style khorn does the top "home plate" piece serve the function of directing or containing the bass frequencies or does it simply look nice tucked all the way in the corner? Do decorator khorns have something that extends into the corner at the top of the LF section? D-Man your speaker doe not appear to have any sort of corner "point" are they sealed in the back and in turn do not need to be tucked tight into the corner of the room? It looks khorn like but obviously not a khorn.

Thanks, Rich

[Al Klappenberger]

Guys,

From what I have heard, centering the tweeter above the squawker is mainly to eliminate the need to build a left and a right speaker. It's just a manufacturer's production compromise. With the tweeter centered there is no longer a tweeters inboard or outboard question. I get that question quite often with my Trachorn frame. My solution is to make it so it can simply be fliped up-side-down. That moves the tweeter to the opposite side.

AL K.