Mikerodrig27

I messaged him 4 days ago. No response. I suspect it has sold already.

So did you ever get a chance to finalize your listening impressions between the ALK universals and the AA's? I know this is an old thread but I am interested to hear the results. Thanks!

Looking great so far! I do agree that a single piece of wood cut to the dimensions of the splitter would be the simplest solution. Are you going to seal that piece of wood above the splitter? I high grade caulking would probably work.

Very cool. keep up the good work! What are you going to do for a finish?

I know this is an old post but I want to add to it. I don't have the 2ce but I just bought the 2ci and am testing them against the Forte I's in my living room. The Vandersteens are so much less fatiguing. I have been listening for about an hour. They don't have the imaging and sound slightly veiled compared to the Fortes. If you want a rock speaker with detail, soundstage etc... forte. if you want a speaker for simple slower music, jazz etc choose the vandersteens. you cant go wrong with either.

Surprisingly, my biggest obstical has been learning how to do nearfield testing with a calibrated mic that I bought (UMM-6). My latest knowledge is that you measure the woofer, the port and depending on how high in frequency your test goes, mid and tweeter. All nearfield. Once I figure out the tuning frequency, I am going to order a precision port: https://www.parts-express.com/precision-port-4-flared-speaker-cabinet-port-tube-kit--268-352 I have a pair of Forte I's that I am comparing them to. As of right now, I can say the new cabinets, dampening produce way cleaner bass. I have hope!

A few teaser shots on what I hope is progress

Does anyone have any specs on the KD-15 passive radiator? I am building new cabinets for some Forte II's and I want to know if I need to change anything on the PR like weight etc. I was able to model the woofer in WinISD as a vented cabinet and it models well going larger tuned to the same frequency. Just don't know how to tell with the PR. Thanks!

I need to recone one passive radiator. It is all beat up from the Previous owner. I am leaning towards not messing around with the weight. I think the 15" driver is fragile. Messing with the broken one a little bit it seems to be a rather thin material that rips easily. Awesome. I never liked the tall skinny look of the Forte's. This will help mitigate that. Between the extra depth for the bracing that I am going to add and the 3/4" of depth it should help mitigate that. Using tlarwa's spec of the bracing taking up 3.5% of the space, that would ad a depth of roughly 1/2". That combined with the 3/4" will equal 1 1/4" of extra depth. I agree that I can just fill the space if I don't like the sound for some reason. Thanks for all of the responses!

Thanks for the responses. I may try building one a little larger to see what it sounds like. I eventually want to get a MiniDSP mic or something similar to measure results. From what I have seen with DIY speaker kits, enlarging the cabinet, switching from ported to bass reflex doesn't require crossover changes. This is with fairly high end speakers as well. I am going to start doing some research tomorrow night (tonight I am finishing up a rebuild of a Marantz 2215b). From my brief time reading about it, the passive radiator (PR) acts as a port essentially. If I enlarge the volume in the cabinet, I need to add a little more weight to the PR in order to tune it down so that the woofer doesn't put out too much bass. I guess the only question is, will the woofer work well in a larger lower tuned cabinet. Dampening I am not concerned with. I can add and remove that easily. I will have some bracing in the new cabinets. The dampening would be to just cut down on reflections in the cabinet. There is a lot of dialogue that comes from the woofer... At least in my Forte I's (another set that I have) that I have spent some time messing with.

I just bought a pair of Forte II speakers. All of the drivers except for one passive radiator are in great shape. I found a recone kit that will solve that problem. I wanted to see if anyone had suggestions on modifying the dimensions on the cabs etc. I was thinking of adding an extra 1/2" of depth so that i can add bracing to the inside and not take up too much volume. Then I thought, would adding 2" of volume make the speaker sound better? Let me know if any of you have successfully modified the specs of the cabinets. I will be reusing the front baffles but that is it. I may be able to salvage the rears but I don't think they are critical. I will likely wrap these in walnut veneer like the originals. Other thoughts are Mahogany which is cheaper and more spectacular looking. image uploader

Push in (gently) on the woofer, hold it in for a few seconds and let go. See how long it takes to go back to rest. This is essentially a measurement of how leaky the cabinet is. Common places that the speakers leak are the robber graumets where the speaker grill pegs go into (the are drilled through the baffle.), the surrounds delaminating from the cone or basket (not super common but it happened on my passives), screw holes, and maybe the gasket behind the speaker baskets where they mate to the cabinets (not super common from my experience.) I refoamed my passive radiators and put weather seal from H Depot for the gasket. Worked great. I found the graumets to replace some worn out ones on my speakers surprisingly in my hardware stash but they are available online. ALK Engineering has modified crossovers for the Forte I's and II's. He redesigned them to correct a few issues with the original design. There is a thread on it. I was talking to someone who mentioned the aftermarket Titanium tweeter diaphragms measured higher in distortion than the Klipsch titanium replacements. He is an engineer for Klipsch. klipsch part number is 12712. If I think of anything else I'll post it here. I am sure others on this forum will have more insight than I do.

I was rereading this and realized that you had mentioned Simply Speakers. I got these foams from The Speaker Exchange. One of the employees there guided me through how to measure, looked up the proper foams and sold me a kit. Air passing through doesn't seem to be a problem. Passes the test of how long it takes them to return to normal after pressing on the woofer so they are sealed enough. 😁 I have had the new foams on for a while now and they haven't skipped a beat

I added up the parts and it comes out to roughly $220 shipped to Florida. Alks premade crossover is a good deal it sounds like. You would save a little over $100 by doing it yourself.

Yes. The passive radiater. I believe they had known parts for the 15". I had to measure and find something that would work for the 12-inch passive radiator. Who knows if it perfect as I have never heard one without holes but my speakers have stronger low end w/ the repaired surrounds. There was another surround but I believe it was rubber. Maybe it was a closer match but I didn't want to try it. There were more measurements for the rubber one. I will try to remember to post a link.

Okay, so I ended up making progress on this. I replaced my surrounds with a new set that I got from The Speaker Exchange. I went back and forth with Geno through email and he suggested a couple of kits. This is what I ordered: https://reconingspeakers.com/product/12-refoam-kit-for-mcintosh-rfk12-mac/?attribute_pa_quantity=kit-pair2-foams2-caps1-glueshimsinstructions&attribute_pa_dust-cap=dcf4500-felt-dc-4-5-od-dome-lip-up "Brand New 12″ Polyether Flat Attach Speaker Foam Repair Kit. Works for most 12″ McIntosh woofers." RFK12 MAC Outside Diameter: 11.750″ (298.45 mm) Inside Diameter: 9.0″ (228.60 mm)" The dimensions were perfect except for the size of the round part. That was a little large. However I think they are a decent replacement. The old ones peeled off very easily. I got the full kit which came with some really good contact cement. I sprayed the speaker cone and front of the frame with some black paint to freshen them up. It didn't take much. I thought about whether I should or not and came to the conclusion that the paint doesn't weight enough to make a difference and I've read of people increasing the weight of the passive radiator anyways. After I sprayed the cone and frame, I waited for it to dry then installed the new foam. I put the foam on the cone first with the glue being slightly still wet so I could manipulate it a little bit. I just kept on manupulating the foam and eventually the foam started to stick in place. Took about 2 minutes. Where the surround attached to the frame, I just went ahead and let the glue dry to the point where it was tacky like you are supposed to.

I googled it. You are right. Seems like your off hand info is excellent. Thanks! I messaged a couple of online speaker repair part retailers before posting this thread. I will relay any good info they give me in case someone tries to look this up in the future.

I am actually kind of surprised by that since the Forte's are such a popular speaker. Do you know off hand if the passive radiator has a certain name? I know a lot of referred by k-XX Thanks!

has anyone replaced them? If so, where'd you source the parts. Thanks!

Pretty sweet. I know this thread is old but I saw no one gave their opinion. I need to replace the surround on one of my forte I's passives. Might just do both to keep things consistent and the dye trick as well to spruce them up.

Looks Great! Was it expensive to build? I just picked up a set of Forte 1's in fair condition. They sound great though. I want to upgrade the crossover as well as the tweeter dome and I was thinking I would go with Alk's design. It is nice that he posted it here so many can see and use it.