I'm planning to build a pair of Scott Lindgren's Haruna speakers from frugal-horn.com, already have the FE166En but have a few questions, if anyone can advise.
1) The biggest problem is that I'm in Azerbaijan and have discovered that birch ply only seems to be available in 1.5m square sheets, whereas Haruna is 1.85m tall.
I suspect that issue is going to force me to use MDF. But I wonder if it might be a worthwhile "compensation" to increase the side panels from 19mm to 25mm thick? They will be quite a bit heavier but that's only really a problem during the build.
We do have businesses here that cut MDF to size, so that might actually make the project much easier - it can also come with various finishes, but then I couldn't use a nail gun to fix the internals in place, which is what I did with my Dallas 2. Though I could also veneer the outside afterwards.
2) The instruction says "you may replace the stacked corner deflectors with a single angled piece". If I used an angled piece I would then create a hole that needed to be filled with sand etc. so that actually seems to be a disadvantage. But is there any technical preference one way or the other of a step vs. a smooth surface?
3) The default damping is "line 5 faces of the driver chamber with 1/2" material...ensuring the throat remains clear" - so this seems to mean that the 6th side, with no damping, is the back side of the baffle?
4) In my Dallas 2s I lined the driver chamber with 3mm felt, using a spray glue, but it made a helluva mess as it was difficult to spray accurately. Maybe a liquid glue would have been better, but I was wondering if an alternative way would be to glue velcro in the driver chamber and use cut-to-size pieces of 12mm wool felt so that the damping was removable. This approach would also perhaps let me experiment with different materials in the future. Or is it important that the lining is hard-fixed to the cabinet over all its surface?
5) I've seen a couple of threads where the builders have added a supertweeter here and here, though they both seem to be using a Fostex FE168E Sigma. Is this something that I need to be considering for a standard FE166En? One puts the supertweeter inside the cabinet above the main driver, one hangs it off the side.
6) Last one for now, any thoughts as to whether an ACA Mini will work OK with these? I don't listen extremely load, but do plan to put these in a large listening room.
Thanks!
1) The biggest problem is that I'm in Azerbaijan and have discovered that birch ply only seems to be available in 1.5m square sheets, whereas Haruna is 1.85m tall.
I suspect that issue is going to force me to use MDF. But I wonder if it might be a worthwhile "compensation" to increase the side panels from 19mm to 25mm thick? They will be quite a bit heavier but that's only really a problem during the build.
We do have businesses here that cut MDF to size, so that might actually make the project much easier - it can also come with various finishes, but then I couldn't use a nail gun to fix the internals in place, which is what I did with my Dallas 2. Though I could also veneer the outside afterwards.
2) The instruction says "you may replace the stacked corner deflectors with a single angled piece". If I used an angled piece I would then create a hole that needed to be filled with sand etc. so that actually seems to be a disadvantage. But is there any technical preference one way or the other of a step vs. a smooth surface?
3) The default damping is "line 5 faces of the driver chamber with 1/2" material...ensuring the throat remains clear" - so this seems to mean that the 6th side, with no damping, is the back side of the baffle?
4) In my Dallas 2s I lined the driver chamber with 3mm felt, using a spray glue, but it made a helluva mess as it was difficult to spray accurately. Maybe a liquid glue would have been better, but I was wondering if an alternative way would be to glue velcro in the driver chamber and use cut-to-size pieces of 12mm wool felt so that the damping was removable. This approach would also perhaps let me experiment with different materials in the future. Or is it important that the lining is hard-fixed to the cabinet over all its surface?
5) I've seen a couple of threads where the builders have added a supertweeter here and here, though they both seem to be using a Fostex FE168E Sigma. Is this something that I need to be considering for a standard FE166En? One puts the supertweeter inside the cabinet above the main driver, one hangs it off the side.
6) Last one for now, any thoughts as to whether an ACA Mini will work OK with these? I don't listen extremely load, but do plan to put these in a large listening room.
Thanks!
I wish I could help. reach out to dave at planet 10. I believe he created the “en” modification several years ago. If anyone can help it’s him, very knowledgeable and humble.
I’ve not heard of the Haruna before but l will search the net to see
Best of luck to you and stay safe
I’ve not heard of the Haruna before but l will search the net to see
Best of luck to you and stay safe
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I suspect the 'En' refers to the Fostex FE166En drive unit, which replaced the FE166E, and was itself replaced about a year ago with the current FE166NV. I designed Haruna for the FE166En just after that drive unit's release. Dave's modified units reversed the capitalisation in the name, so in the case of this model, they would have been the FE166eN.
Re the questions, in order:
1/ It wouldn't hurt (apart from your back, obviously 😉 )
2/ In this case, no. There are some differences, but not at such a level as to be audible. I prefer the former myself as it adds a little extra structural rigidity, but YMMV.
3/ Actually it means the front baffle. Rear baffle should be lagged to kill reflections: just don't block the throat
4/ It's not critical, so whatever you prefer. Most (always some exceptions) thicker materials will often stay in place with a friction-fit alone. Velcro is fine if you prefer -I can sympathise re the spray-glue, it's not always the easiest to work with. A liquid glue should do also.
5/ More or less a case of 'as you prefer'. Truth to tell, most supertweeters are not added with a proper crossover, so there is quite a lot of destructive interference between it and the main driver -what and how depending on the supertweeter & how it's added in. My own suspicion is that in a number of cases, possibly a majority, people like the results but they're not necessarily getting much more on the top end, if any. Unfortunately, this is really down to the individual. I would simply say that if you add one, make sure it's physically as close to the main driver as you can get it.
6/ Should do reasonably in load terms.
Re the questions, in order:
1/ It wouldn't hurt (apart from your back, obviously 😉 )
2/ In this case, no. There are some differences, but not at such a level as to be audible. I prefer the former myself as it adds a little extra structural rigidity, but YMMV.
3/ Actually it means the front baffle. Rear baffle should be lagged to kill reflections: just don't block the throat
4/ It's not critical, so whatever you prefer. Most (always some exceptions) thicker materials will often stay in place with a friction-fit alone. Velcro is fine if you prefer -I can sympathise re the spray-glue, it's not always the easiest to work with. A liquid glue should do also.
5/ More or less a case of 'as you prefer'. Truth to tell, most supertweeters are not added with a proper crossover, so there is quite a lot of destructive interference between it and the main driver -what and how depending on the supertweeter & how it's added in. My own suspicion is that in a number of cases, possibly a majority, people like the results but they're not necessarily getting much more on the top end, if any. Unfortunately, this is really down to the individual. I would simply say that if you add one, make sure it's physically as close to the main driver as you can get it.
6/ Should do reasonably in load terms.
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To answer no.4 you can attach the felt with double sided adhesive tape for rugs.
Clean job and easy to remove/modify.
Firm gluing the whole surface of the felt is not necessary. Its main purpose is to prevent HF reflections inside chamber.
Clean job and easy to remove/modify.
Firm gluing the whole surface of the felt is not necessary. Its main purpose is to prevent HF reflections inside chamber.
eN was the suffix i used on modified FE166e. Then Fostex appropriated it, but we also moved to EnABL 2 so an FE166En would become an FE166eN2.
These are the phase plugs for FE166. http://www.planet10-hifi.com/downloads/FE16x-PhasePlugs.pdf
dave
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Be it wide range drivers or horns; learned the long, tedious, hard way since I didn't accept the pioneer's conclusions based on reverse engineering their designs that capped off really high to only allow top end 'air' (> 16 kHz) through at reference eff. levels works best overall simply because apparently 'we' can't locate it in space and at 1st order 'we' historically don't run the risk of making the tweeter's ~6-8 kHz too 'sibilant' or its ~8-16 kHz octave too 'brittle'.
The only downside for most folks is one ideally needs a true super tweeter horn or multiple ~tiny tweeters to get the necessary BW and/or efficiency.
Glue for felt: this guy use the same kind of glue that is used to glue vinyl floor tiles http://www.troelsgravesen.dk/tips.htm#Gluing_felt_and_acoustilux
In my experience that thing that vibrates the most is the free ends of horn. So some bracing at the horn opening will work as well as using back and bank breaking thick MDF.
In my experience that thing that vibrates the most is the free ends of horn. So some bracing at the horn opening will work as well as using back and bank breaking thick MDF.
Haruna progress is that after taking an age to rework the design from 19mm to 18mm the MDF is finally bought and cut.
I opted for 25mm for the sides, top, bottom and deflector, 18mm for the baffle and insides. One side panel is about 16kg so it's going to be pretty heavy - somewhere upwards of 50kg each.
Layout is all marked out and pieces roughly positioned to check that layout looks ok. With almost everything right angled this looks a lot easier than my Dallas 2s.
Next step is to buy a dowel jig on my next trip back to the UK in a week's time, then construction can begin in earnest..
I'm thinking about opening up the space behind the bottom deflector to put an ACA Mini, maybe one each side if I can bridge them. Then cut a small slot in the outside back and run one pair from a Cat5E cable up to the back of the throat.
I opted for 25mm for the sides, top, bottom and deflector, 18mm for the baffle and insides. One side panel is about 16kg so it's going to be pretty heavy - somewhere upwards of 50kg each.
Layout is all marked out and pieces roughly positioned to check that layout looks ok. With almost everything right angled this looks a lot easier than my Dallas 2s.
Next step is to buy a dowel jig on my next trip back to the UK in a week's time, then construction can begin in earnest..
I'm thinking about opening up the space behind the bottom deflector to put an ACA Mini, maybe one each side if I can bridge them. Then cut a small slot in the outside back and run one pair from a Cat5E cable up to the back of the throat.
