Hi all,
This is my first post here after trying to read all the threads that already brought me a bunch of answers (and many new pages to read in the infinite knowledge that one can find on the internet).
My challenge is as follows: I inherited a pair of beautifully designed but quite badly sounding design speakers from the 70's. The enclosures are spherical brushed aluminium with a diameter of about 20cm diameter (8 inches). The driver inside is about 5 inches (133 mm BCD, slightly smaller baffle) and a tiny tweeter in front. Both straight from the 70's and well... sound as such
. After a bit of research I have decided that I would like to replace this combination with a single full range driver as I like the simplicity and philosophy of the single driver.
The full range driver has to fit in this existing enclosure, so I am limited to something between 4 and 5 inches. The air volume in the (closed enclosure) is about 1 or 2 liters (depending on the driver one puts in there).
I understand that in these conditions I will not be able to have a very much in the lower freq range... but there is not much I can do about that I think (right?)
I listen all kind of music, but almost no jazz and no classical music.
I driver my speakers with a rotel pre-amp and a NAD 216 amp.
Now the question: which driver should I choose?
I have been doing some research already and ended up on the likes of TangBand and Fostex. How do these compare?
As this is my first build project (well, for speakers at least), I would be happy with any advice I can get.
This is my first post here after trying to read all the threads that already brought me a bunch of answers (and many new pages to read in the infinite knowledge that one can find on the internet).
My challenge is as follows: I inherited a pair of beautifully designed but quite badly sounding design speakers from the 70's. The enclosures are spherical brushed aluminium with a diameter of about 20cm diameter (8 inches). The driver inside is about 5 inches (133 mm BCD, slightly smaller baffle) and a tiny tweeter in front. Both straight from the 70's and well... sound as such
. After a bit of research I have decided that I would like to replace this combination with a single full range driver as I like the simplicity and philosophy of the single driver.The full range driver has to fit in this existing enclosure, so I am limited to something between 4 and 5 inches. The air volume in the (closed enclosure) is about 1 or 2 liters (depending on the driver one puts in there).
I understand that in these conditions I will not be able to have a very much in the lower freq range... but there is not much I can do about that I think (right?)
I listen all kind of music, but almost no jazz and no classical music.
I driver my speakers with a rotel pre-amp and a NAD 216 amp.
Now the question: which driver should I choose?
I have been doing some research already and ended up on the likes of TangBand and Fostex. How do these compare?
As this is my first build project (well, for speakers at least), I would be happy with any advice I can get.
thanks for you reply. I'll get some pictures tomorrow.
The slice that comes off the sphere is about 1/2 to 1 liter so I don't lose too much there. Then comes the volume of the driver itself. So I am indeed left with something like 2-2.5 liters depending on the driver chosen.
This FF85WK you recommend is smaller than what I could mount in there. What is the reason that you recommend this one in particular? (note: i don't doubt your choice, I just want to learn...)
The slice that comes off the sphere is about 1/2 to 1 liter so I don't lose too much there. Then comes the volume of the driver itself. So I am indeed left with something like 2-2.5 liters depending on the driver chosen.
This FF85WK you recommend is smaller than what I could mount in there. What is the reason that you recommend this one in particular? (note: i don't doubt your choice, I just want to learn...)
Every driver requires a certain volume to work its best, with the given volume those 3 drivers are what i know works. A larger driver would need greater volume, there are quite a few 5" that can work in 4.5-4.7 litre, but that is as small as i'd put them in.
The 3 mentioned drivers, althou somewhat bass limited are no slouches in the range they do work in.
dave
The 3 mentioned drivers, althou somewhat bass limited are no slouches in the range they do work in.
dave
If you can neatly attach a round plate to the hole in the speaker then in the middle of the plate you can put the FF85WK. Or put it excentric with room for a bass reflex opening below it.
This driver has qualities, but it is not a bass monster. You may want to add a subwoofer to it for complete music enjoyment, possibly also filtering the FF85WK to protect it from the lower frequencies so it can focus on what it does best. To my own taste, a speaker with the FF85WK will not have enough bass on its own.
If you prefer to keep it with 1 driver without sub, then a 3" Tangband is probably a better choice. Since these speakers offer lower efficiency, they can go lower in bass - at the expense of loudness.
This driver has qualities, but it is not a bass monster. You may want to add a subwoofer to it for complete music enjoyment, possibly also filtering the FF85WK to protect it from the lower frequencies so it can focus on what it does best. To my own taste, a speaker with the FF85WK will not have enough bass on its own.
If you prefer to keep it with 1 driver without sub, then a 3" Tangband is probably a better choice. Since these speakers offer lower efficiency, they can go lower in bass - at the expense of loudness.
Same with Alpair 6.2s. Also the Fountek FR88ex
FF85wk with helper woofers are pretty amazing.
dave
Thanks again for all the answers and advice
The aluminium is 2mm thick. Here are some images of the spheres in original state and after partial disassembly:
(the last one is just to show the part that is 'sliced off')
I was not really planning on adding a filter. It adds more complexity to my first project, and because placing the filter inside these spheres will 1) take away even more volume, and 2) be a real challenge to mount / fix in a proper way. Additionally: isn't the beauty of full range that you don't need filters?
As the original way these were made is just a sealed volume, I was planning on doing the same, so I had not thought of a BR design... would you indeed recommend this?
With these speaker I would rather consider adding a subwoofer than pushing the lows on the spheres themselves. And I value a clean sound over volume for this project.
The aluminium is 2mm thick. Here are some images of the spheres in original state and after partial disassembly:
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
(the last one is just to show the part that is 'sliced off')
I was not really planning on adding a filter. It adds more complexity to my first project, and because placing the filter inside these spheres will 1) take away even more volume, and 2) be a real challenge to mount / fix in a proper way. Additionally: isn't the beauty of full range that you don't need filters?
As the original way these were made is just a sealed volume, I was planning on doing the same, so I had not thought of a BR design... would you indeed recommend this?
With these speaker I would rather consider adding a subwoofer than pushing the lows on the spheres themselves. And I value a clean sound over volume for this project.
It would really depend on the sealed system's Q [sysQ]. In such a small cab though, a damped vented alignment [semi-aperiodic] is often the best overall compromise.
An easy test for vented is to gap [space] the driver to create a leaky seal with the greater the gap, the higher it begins rolling off in the bass.
Adding foam or similar in the gap can also change its tone, creating an increasingly aperiodic alignment with increasing density, so worth experimenting with also.
GM
An easy test for vented is to gap [space] the driver to create a leaky seal with the greater the gap, the higher it begins rolling off in the bass.
Adding foam or similar in the gap can also change its tone, creating an increasingly aperiodic alignment with increasing density, so worth experimenting with also.
GM
Sounds cool... Can you give me a ballpark idea of how 'leaky' my seal has to be? i.e. how much of a gap I should leave between the driver and the board it will be mounted on (there are no drivers with the exact mounting pattern of the old drivers, so for sure I will have to do some woodwork...).
Is it mm's? or rather cm's? (assuming I will use a 3 inch driver).
Is it mm's? or rather cm's? (assuming I will use a 3 inch driver).
Hi,
With 2L/3L your limited to 3" drivers pretty much.
Vented loading is pretty much not a option.
A 20cm internal sphere calculates to about 4.2 litres.
Its quite important to be say +/- 10% accurate with estimations.
About 1 or 2 litres is not particularly helpful.
(19cm internal is 3.6 litres).
If they will be bass filtered, you can go for a fairly low excursion driver.
(FWIW for small speakers clean sound is very volume related.
Driver excursion determines up to what volume they remain
clean, and that is modest for the best of them and pathetic
for the ones that simply cannot do bass in the first place.)
If not, you need a 3" with decent excursion. You will need a filter
to get them to sound balanced due to BSC, line level or build it into
an external box in the speaker leads. Some drivers benefit from
additional filters to smooth the frequency response somewhat.
Madisound Speaker Store
Is probably the best 3" to use (with line level BSC) for bass.
Try to mount the driver offset to smooth the baffle ring ripple.
rgds, sreten.
See http://www.zaphaudio.com/archives.html and http://www.zaphaudio.com/smalltest/
Also see the general write up on small FR's http://www.zaphaudio.com/audio-speaker18.html
With 2L/3L your limited to 3" drivers pretty much.
Vented loading is pretty much not a option.
A 20cm internal sphere calculates to about 4.2 litres.
Its quite important to be say +/- 10% accurate with estimations.
About 1 or 2 litres is not particularly helpful.
(19cm internal is 3.6 litres).
If they will be bass filtered, you can go for a fairly low excursion driver.
(FWIW for small speakers clean sound is very volume related.
Driver excursion determines up to what volume they remain
clean, and that is modest for the best of them and pathetic
for the ones that simply cannot do bass in the first place.)
If not, you need a 3" with decent excursion. You will need a filter
to get them to sound balanced due to BSC, line level or build it into
an external box in the speaker leads. Some drivers benefit from
additional filters to smooth the frequency response somewhat.
Madisound Speaker Store
Is probably the best 3" to use (with line level BSC) for bass.
Try to mount the driver offset to smooth the baffle ring ripple.
rgds, sreten.
See http://www.zaphaudio.com/archives.html and http://www.zaphaudio.com/smalltest/
Also see the general write up on small FR's http://www.zaphaudio.com/audio-speaker18.html
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The range in volume is due to the uncertainty in driver choice. I will do a quick measurement of the true inner volume (without driver), so I can give you a better number.
As for the drivers (thanks for the link, a very useful review for a newby like me), it looks like there are 4 recommended ones now:
Fostex FF85WK
Aurasound NS3
Alpair 6.2
Fountek FR88ex
Assuming I don't want any filters, and consider adding a sub later, which one is the 'best' ?
As for the drivers (thanks for the link, a very useful review for a newby like me), it looks like there are 4 recommended ones now:
Fostex FF85WK
Aurasound NS3
Alpair 6.2
Fountek FR88ex
Assuming I don't want any filters, and consider adding a sub later, which one is the 'best' ?
I've no experience with cabs this small, but I guess mm since I would start with just a standard flat washer of whatever size is appropriate for the mounting hardware.
GM
If you pop over to here
mh-audio.nl - Home
and type in your specs for a couple of proposed drive units, it will give you some idea of how they will perform in a sealed box. There is also a vented box calculator on the same site.
mh-audio.nl - Home
and type in your specs for a couple of proposed drive units, it will give you some idea of how they will perform in a sealed box. There is also a vented box calculator on the same site.
I have 3 litre sealed round enclosures with Jordan JX92S drivers in and they sound impressive for their size.
The EAD E100 is most like the driver I have, but Jordan are bringing a new driver out to replace the KX92S which looks very promising.
An externally hosted image should be here but it was not working when we last tested it.
The EAD E100 is most like the driver I have, but Jordan are bringing a new driver out to replace the KX92S which looks very promising.
Wow. Beautiful speakers! I looked up the jordans, but at 180USD a piece i think I will start this project with slightly cheaper units
If I really like the sound of these 3L things, I might consider an upgrade in drivers later on...
Oh and one more question: i am based in the netherlands. What is the best webshop to order these components? I find lots of US-based shops, but few in Europe...
If I really like the sound of these 3L things, I might consider an upgrade in drivers later on...
Oh and one more question: i am based in the netherlands. What is the best webshop to order these components? I find lots of US-based shops, but few in Europe...
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I would seriously consider these if you want to start off on a budget.
match pair (2pcs) HiEND 4inch full range fullrange speaker defy lowther & fostex | eBay
Although do bear in mind that what you get from one pair of speakers can be totally different from what the Jordan's do, so in some ways if you don't like the results at first maybe you shouldn't rule them out.
match pair (2pcs) HiEND 4inch full range fullrange speaker defy lowther & fostex | eBay
Although do bear in mind that what you get from one pair of speakers can be totally different from what the Jordan's do, so in some ways if you don't like the results at first maybe you shouldn't rule them out.
I ran a few calculations for all on Speakerbuilder Pro 2.0 and the Aura NS3 seem to have the best response for my cabinet size (both sealed and ported). And they are they only ones 'recommended' by zaph if I want to run it really without any filters.
So I think I will start off with those. And they are relatively cheap, so if I don't like them, it's not a big problem...
Now a place to order them.
So I think I will start off with those. And they are relatively cheap, so if I don't like them, it's not a big problem...
Now a place to order them.
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