Right, one-off post just to preempt any questions.
Based on the data sheets provided as of this date:
-In load terms the new / forthcoming Fostex FE103NV and FE126NV will go straight into FH3, the latter preferably with a slightly higher output impedance amplifier, or being better suited to those who have said, same as its FE126En predecessor.
-Xmax. The current data for the new NV series does not provide a value for this, nor are coil length & gap dimensions provided. Best guess is that it will be similar to the departing FExx6En series drivers, or at the most similar to the FFxx5wk units. Since I'm not spotting major physical differences, I'd guess close to the former. Fostex units tend to overload fairly progressively (in relative terms) though, and Xmax itself is not some kind of static point. It has nothing to do with Small and his electrical filter derivations, even though it's often included in T/S parameters. If anybody's interested, this is what Small said in his original paper: 'it is assumed that a peak displacement limit can be established; this limit is designated Xmax', and that '[it is assumed] that diaphragm displacement is linear up to Xmax'. That's it. No method. No fixed value. Just an assumption. The many various methods that exist for generating a number that can be described as Xmax are all essentially assumptive, and they also tend to give different values if applied to the same driver. It's a loose guide to the motor configuration and priorities of the design; I really wouldn't try reading too much profundity into it, because to do so is to assign a significance to it that factually isn't there.
Based on the data sheets provided as of this date:
-In load terms the new / forthcoming Fostex FE103NV and FE126NV will go straight into FH3, the latter preferably with a slightly higher output impedance amplifier, or being better suited to those who have said, same as its FE126En predecessor.
-Xmax. The current data for the new NV series does not provide a value for this, nor are coil length & gap dimensions provided. Best guess is that it will be similar to the departing FExx6En series drivers, or at the most similar to the FFxx5wk units. Since I'm not spotting major physical differences, I'd guess close to the former. Fostex units tend to overload fairly progressively (in relative terms) though, and Xmax itself is not some kind of static point. It has nothing to do with Small and his electrical filter derivations, even though it's often included in T/S parameters. If anybody's interested, this is what Small said in his original paper: 'it is assumed that a peak displacement limit can be established; this limit is designated Xmax', and that '[it is assumed] that diaphragm displacement is linear up to Xmax'. That's it. No method. No fixed value. Just an assumption. The many various methods that exist for generating a number that can be described as Xmax are all essentially assumptive, and they also tend to give different values if applied to the same driver. It's a loose guide to the motor configuration and priorities of the design; I really wouldn't try reading too much profundity into it, because to do so is to assign a significance to it that factually isn't there.
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I might give them a shot, a buddy from work has them in a karlsonator and they sound very, very good indeed, at least for the cost. XRK971 also seems pretty impressed by them.
A little light up in the higher frequency, but a reasonable tweeter shouldn't be too difficult to integrate. I was eventually going to grab a pair of the GRS 15" woofers used in the Manzanita OBs soon so figured it would be the time to buy a pair of the Daytons to play with too. Worse case they end up as shop/garage speakers.
If you like the drivers, and they physically fit, then the way forward is clear.
jeff
Any time the drivers being crossed over have a centre-to-centre distance of over a quarter wavelength of the XO frequencies you start to have significantly more issues with integration. At the frequencies you are talking about the c-c is mny wavelengths, and wher eyou listen from (and how) has a large effect on the way the interference between the 2 drivers exhibits itself.
You will find it can be a crapshoot, good luck.
dave
Maybe a supra baffle with a tweeter mounted close? It'll make upgrade to a nicer driver later on easy enough. Simply swap it over and go?
This is all planning for now. I may just build a set of the lites with the TC9FD or Fountek FE83 first and see how I like the design on a small scale first, since I have those drivers on hand already.
This is all planning for now. I may just build a set of the lites with the TC9FD or Fountek FE83 first and see how I like the design on a small scale first, since I have those drivers on hand already.
I've got a new in box "matched pair" marked set of Fountek FE83 from the raffle at Burning Amp 2018, so I'll focus on a set of the FH lites using them for now. Thanks!
Besides, I feel like if I'm going to go big I may as well spend a smidge more later and do a set of XL if I need to buy larger drivers anyway.
Besides, I feel like if I'm going to go big I may as well spend a smidge more later and do a set of XL if I need to buy larger drivers anyway.
First of all, I thank you for all your contributions, since they are essential for newbies like me to learn.
It seems that Mark Audio alpair 7.3 drivers are discontinued.
What would be the most recommended drivers?
Is Pluvia 7.2 HD the substitute?
Is there a lot of difference in sound quality between the Pluvia 7.2 HD and the CHR-70?
For these drivers, the recommended wood thickness is 15mm?
Do they need a thickness of 18 mm for driver installation?
I apologize if these are questions that have already been asked.
Thanks again from Spain!
It seems that Mark Audio alpair 7.3 drivers are discontinued.
What would be the most recommended drivers?
Is Pluvia 7.2 HD the substitute?
Is there a lot of difference in sound quality between the Pluvia 7.2 HD and the CHR-70?
For these drivers, the recommended wood thickness is 15mm?
Do they need a thickness of 18 mm for driver installation?
I apologize if these are questions that have already been asked.
Thanks again from Spain!
With the newer thin bezel profiles of the Pluvia series - which don’t need rebating- I’d opine that 15mm material would be sufficient for the baffles. Planet10 kits used 18mm there only to accommodate the deep rebate required for the much thicker frames of the original Alpair and CH70s, etc. For that matter, rebating is also not required for the Fostex drivers most commonly used in FH family.
In all cases, just be sure to chamfer the rear side of driver mounting hole - which is way easier to do with a small trim router and 45dg bit before assembly, and as these drivers are small and light enough, I found that when using high quality Baltic birch type plywood, there was more than enough screw retention even with a deep chamfer and fairly thin shoulder. I.e. cut the mounting hole with hole saw or router circle jig, and set the depth of cut in bevel big so the inside edge of bottom mounted bearing has approx 3-4mm of contact.
And with carefully sized pilot holes and hand tapping before installing the drivers, I found the coarse thread hex head screws supplied with the MA drivers to be ideal - just don’t over tighten them.
In all cases, just be sure to chamfer the rear side of driver mounting hole - which is way easier to do with a small trim router and 45dg bit before assembly, and as these drivers are small and light enough, I found that when using high quality Baltic birch type plywood, there was more than enough screw retention even with a deep chamfer and fairly thin shoulder. I.e. cut the mounting hole with hole saw or router circle jig, and set the depth of cut in bevel big so the inside edge of bottom mounted bearing has approx 3-4mm of contact.
And with carefully sized pilot holes and hand tapping before installing the drivers, I found the coarse thread hex head screws supplied with the MA drivers to be ideal - just don’t over tighten them.
Hello Cuchi,
Don't worry too much about making mistakes, there's always a way around them. I cut a cut a speaker hole to0 high and made the other one a little bit oval. See link below.
Recently I bought a £34 DVD player, well it'll play anything I stick into it. I'd modified a CD player before that, the new one knocks spots off it. I now listen to a wall of full range Tangerine Dream sound at their concert level, laughing my socks off.
Cheers
Don't worry too much about making mistakes, there's always a way around them. I cut a cut a speaker hole to0 high and made the other one a little bit oval. See link below.
Recently I bought a £34 DVD player, well it'll play anything I stick into it. I'd modified a CD player before that, the new one knocks spots off it. I now listen to a wall of full range Tangerine Dream sound at their concert level, laughing my socks off.
Cheers
Thank you very much for the encouragement, there is always fear of making mistakes before starting such a project. By the way, I already knew your blog about the Frugel Horn Mk3. Congratulations and thank you very much, it is very helpful!
I have doubts about the recommended amplifier for these speakers. As I read in the forum, it is generally recommended to use tube amps, with a power between 3.5 and 15 watts per channel.
I have a Kenwood 3020 amplifier with 30 watts at 8 ohms. I also have a TPA 3116 with 25 watts at 8 ohms. I usually use them with Fx Audio Tube 01 tube preamplifier.
In case of using the Pluvia 7.2 HD speakers, could I use any of my amplifiers with the Frugel Horn?
Hi, im new here and quite new to diy audio building so i would be grateful for little help.
Im planing to build Frugel-Horn MK3 with MA CHP-70 and asking on few opinions on materials. I have some 18 mm okoume plywood that im planing to use for build, it is light water resistant plywood for boats so will that be good as birch plywood?
Im also have bag of long combed natural wool, would that be ok for damping instead poly-fluff?
And last, its hard to find cotton or wool felt here but maybe i can manage to find some technical wool felt like this : Technical Felt : Manufacturer of Technical wool felt
Is that felt to much thick?
Thanx
Tomislav
Im planing to build Frugel-Horn MK3 with MA CHP-70 and asking on few opinions on materials. I have some 18 mm okoume plywood that im planing to use for build, it is light water resistant plywood for boats so will that be good as birch plywood?
Im also have bag of long combed natural wool, would that be ok for damping instead poly-fluff?
And last, its hard to find cotton or wool felt here but maybe i can manage to find some technical wool felt like this : Technical Felt : Manufacturer of Technical wool felt
Is that felt to much thick?
Thanx
Tomislav
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Cindra,
As long as your plywood is good quality, with even surfaces and does not have too many voids, you should be ok. Baltic birch ply is not a must and 18mm is more than enough thickness.
Poly-fluff would be probably a "safer" choice - have read that natural wool can attract insects, and you would not want that.
What thickness of felt can you find? IIRC the advised thickness is 12mm, but it can slightly less or slightly more. If it is too dense/hard, then maybe it will have less effectiveness. If you can share a picture that will be good.
Can you find jute felt at your place?
As long as your plywood is good quality, with even surfaces and does not have too many voids, you should be ok. Baltic birch ply is not a must and 18mm is more than enough thickness.
Poly-fluff would be probably a "safer" choice - have read that natural wool can attract insects, and you would not want that.
What thickness of felt can you find? IIRC the advised thickness is 12mm, but it can slightly less or slightly more. If it is too dense/hard, then maybe it will have less effectiveness. If you can share a picture that will be good.
Can you find jute felt at your place?
Providing the ply is void free, should be fine.
I would avoid the combed natural wool unless it's been chemically treated to avoid attracting moths. Hollow-fibre pillow stuffing (polyfill, dacron &c) is as noted above a safer choice on that front. The soft technical felt should do, or look for a natural fibre / wool fibre / jute carpet underlay. If it's slightly thicker than usual, you may need less fibre fill.
I would avoid the combed natural wool unless it's been chemically treated to avoid attracting moths. Hollow-fibre pillow stuffing (polyfill, dacron &c) is as noted above a safer choice on that front. The soft technical felt should do, or look for a natural fibre / wool fibre / jute carpet underlay. If it's slightly thicker than usual, you may need less fibre fill.
That part is key in any project
some form of support from better half is much required.
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