I just saw these little Onkyo 4" drivers on madisound for next to nothing:
http://www.madisound.com/catalog/product_info.php?products_id=727
I have never heard a pair of open baffles, so thought it might be an opportunity to throw together a very cheap pair just for the experience.
I was thinking about using 4 per speaker.
I have no real experience with OB speakers or line arrays but a glance at the params indicated they might work ok.
Could someone let me know what kind of baffle size I'd be looking at?
They also have a fairly huge response bump around 2.5kHz (and 9.5kHz actually). Could a couple of passive components help even this out?
I'd like to keep them reasonably small and obviously I have no illusions of getting any real bass out of these.
Many thanks for any help offered.
http://www.madisound.com/catalog/product_info.php?products_id=727
I have never heard a pair of open baffles, so thought it might be an opportunity to throw together a very cheap pair just for the experience.
I was thinking about using 4 per speaker.
I have no real experience with OB speakers or line arrays but a glance at the params indicated they might work ok.
Could someone let me know what kind of baffle size I'd be looking at?
They also have a fairly huge response bump around 2.5kHz (and 9.5kHz actually). Could a couple of passive components help even this out?
I'd like to keep them reasonably small and obviously I have no illusions of getting any real bass out of these.
Many thanks for any help offered.
Wouldn't an 8" driver need a pretty huge baffle if I want open? $3.50 is what I consider next to nothing. I can put 4 in each speaker and including wood have a pair built for $40... I consider that worth it for the experience of hearing a pair of OB arrays.
Bear in mind also I'm from the UK. £20 here buys you a couple of days food
Bear in mind also I'm from the UK. £20 here buys you a couple of days food
valleyman said:
Baffle size is independent of the driver used, it determines the low end response of the speakers. You can read about it here:
http://www.linkwitzlab.com/frontiers.htm#B
Those drivers look ok, so long as you are pairing these OB speakers with a subwoofer or some bass helper drivers.
I had the B20s on 18"x12" baffles for the longest time. Some EQ, and they were good to 50-ish. You could probably get the same from reasonably sized floorstanding baffles without the EQ, or good response into the low/mid 40s with both.
The Onkyos are really too large to make a straight, fullrange array. The center to center spacing it too great, so you will get combing at some point, and the Fs of 96 and only moderate Qts will combine with a narrow baffle to have you start rolling off probably at 120Hz, in room. With multiple drivers, it will probably respond well to EQ, but you're not likely to get anything of value below 80Hz if that low at all.
Kensai
The Onkyos are really too large to make a straight, fullrange array. The center to center spacing it too great, so you will get combing at some point, and the Fs of 96 and only moderate Qts will combine with a narrow baffle to have you start rolling off probably at 120Hz, in room. With multiple drivers, it will probably respond well to EQ, but you're not likely to get anything of value below 80Hz if that low at all.
Kensai
The aim here isnt really to end up with a pair of speakers I'll really use, more just to hear what open baffles sound like.
Am I completely wasting my time just throwing 4 of these onto a baffle say a foot wide by a foot and a half tall? Could make them a bit bigger if necessary
The way I see it I'll end up with some speakers to listen to and then probably just a load of drivers for testing amps. I usually manage to kill one or 2 in the process of building an amp...
Am I completely wasting my time just throwing 4 of these onto a baffle say a foot wide by a foot and a half tall? Could make them a bit bigger if necessary
The way I see it I'll end up with some speakers to listen to and then probably just a load of drivers for testing amps. I usually manage to kill one or 2 in the process of building an amp...
you might as well built it right, how else you would hear how it sounds like
even you do not plan on using it forever
how wide the baffle should be depends how low you want to go
there is a graph circulating here many times over, the repationship on open baffle size and start of low fr rolloff
those 4" speakers will not go too low no matter how wide the baffle
Onkyo 4" Arrays
Just go ahead and do it with whatever size timber you have and can tolerate. I will show the advantages of open baffle and some of the disadvantages.
I have two speaker boxes which I picked up from a streetside hard rubbish collection. The boxes are about 18" tall by 17 inches wide and 5" deep. Each one has four speakers of about 6" dia. and each speaker is a couple of inches in from each corner. A square formation but not tight. Each speaker is 8 ohms and on 1.5 W RMS. I removedd the backs from the speakers and stuck them on some cadboard boxes about 3o" tall. They are hooked up to an old JVC amp ( hard rubbish again). They have a cone tweeter in the middle of the square with one cap. I listen to them all the time!!!! they sound so clean, There are faults but definitely clean and definitely showed the advantages of open baffle. The bass is there but not dominant. Very clean. I favoured horns before but now I have a dilemma.
jamikl
Just go ahead and do it with whatever size timber you have and can tolerate. I will show the advantages of open baffle and some of the disadvantages.
I have two speaker boxes which I picked up from a streetside hard rubbish collection. The boxes are about 18" tall by 17 inches wide and 5" deep. Each one has four speakers of about 6" dia. and each speaker is a couple of inches in from each corner. A square formation but not tight. Each speaker is 8 ohms and on 1.5 W RMS. I removedd the backs from the speakers and stuck them on some cadboard boxes about 3o" tall. They are hooked up to an old JVC amp ( hard rubbish again). They have a cone tweeter in the middle of the square with one cap. I listen to them all the time!!!! they sound so clean, There are faults but definitely clean and definitely showed the advantages of open baffle. The bass is there but not dominant. Very clean. I favoured horns before but now I have a dilemma.
jamikl
Thanks everyone, I'm pretty sure I have the info I need now. I'm going to get them and throw them onto some baffles whose size will probably be determined by what offcuts I have from my fostex build. I understand this is hardly speaker building, and I know not to expect a good sounding pair of OBs with any bass, all I really hope for is to hear the OB sound, and give my mind some basis for extrapolation as to what a good pair of OBs might sound like. (oh and a load of expendable drivers)
Again, thanks for all the input
Again, thanks for all the input
I'd buy a few more, .. aim for , say 9, per side .
It's pretty much a given that you're not going to get much bass out of those drivers. That issue can normally be resolved with a subwoofer.
I think the issue you're going to find (and I've had this issue with an array of small cheap 3" drivers on a test baffle) is that you won't get much midbass either. This isn't going to be so easy to fix, unless you resort to dual subwoofers crossed high, .. and even at that point the subs may not be able to keep up (depending on what you have).
4 drivers per side isn't much of an array. Also, I feel that the treble is going to be "soft"
With more drivers, the peaks in driver response tend to even out.
To avoid digging yourself into a hole, I suggest you build using 9 per side, .. and if/when you are bothered by the issues I've mentioned, consider converting to a 2 way corner loaded, a'la Bill Fitzmaurice TLAH transmission line. That should get you low enough to cross with a sub.
FWIW, in my theater room, I run open baffle line arrays using 2 way 5 1/4 fosters (12 per side) crossed over to a horn sub. Bass is fine up to70 - 80 Hz with useable content below that. For the center channel , I run 6 fosters in a 2x3 open baffle configuration run full range. Not the best, but works acceptable.
Quite happy with it but if I had to re-do my project all over, I'd use more efficient tweeters which can cross a little lower. Being a cheapskate, I get away by boosting the treble a bit on the HT receiver.
Hope that helped.
It's pretty much a given that you're not going to get much bass out of those drivers. That issue can normally be resolved with a subwoofer.
I think the issue you're going to find (and I've had this issue with an array of small cheap 3" drivers on a test baffle) is that you won't get much midbass either. This isn't going to be so easy to fix, unless you resort to dual subwoofers crossed high, .. and even at that point the subs may not be able to keep up (depending on what you have).
4 drivers per side isn't much of an array. Also, I feel that the treble is going to be "soft"
With more drivers, the peaks in driver response tend to even out.
To avoid digging yourself into a hole, I suggest you build using 9 per side, .. and if/when you are bothered by the issues I've mentioned, consider converting to a 2 way corner loaded, a'la Bill Fitzmaurice TLAH transmission line. That should get you low enough to cross with a sub.
FWIW, in my theater room, I run open baffle line arrays using 2 way 5 1/4 fosters (12 per side) crossed over to a horn sub. Bass is fine up to70 - 80 Hz with useable content below that. For the center channel , I run 6 fosters in a 2x3 open baffle configuration run full range. Not the best, but works acceptable.
Quite happy with it but if I had to re-do my project all over, I'd use more efficient tweeters which can cross a little lower. Being a cheapskate, I get away by boosting the treble a bit on the HT receiver.
Hope that helped.
valleyman said:
Hi valleyman,
since you can only go down to 90Hz with those, your baffle
need not be very wide when using a line array ...
One option is to use more drivers and make the array taller.
The baffle should be floor standing.
You will need a subwoofer anyway, equalizing the drivers in
the bass makes no sense due to the very low Xmax of the drivers.
A 80-100Hz highpass will make their lives easier ...
Coating the drivers may be a very good suggestion, at least
on the outer area of the cone because the drivers cones look
rather resonant.
In Germany i use "Ponal" wood glue for that purpose, the normal
one, not "Express".
If you are experienced in XO design you can downsize my
"dipol 08" design a little
www.dipol-audio.de
for a baffle rolloff at 90Hz ...
The baffle will still be about 120 cm tall and about 20cm wide.
Use "Edge" Software from Tolvan Data to optimize baffle size and
driver position. You will need 6 drivers per side then.
Connect the lower 3 and upper 3 as 2 groups in parallel each.
Shunt the lower 3 by an R-C to roll them off smoothly above 1-2
Khz.
Probably you will need some tweaks in the XO ... to get the
things balanced.
Listen to your single drivers and select the smoothest
sounding ones for the upper group of both arrays.
Build baffle and stand robustly and extend the backward
holes for the drivers conically to give as much area as possible
between baffle, cones and baskets.
Possibly you do not want let go your "amp testing speakers"
in the end ...
Cheers
Thanks for the continued interest. I would definitely have gone for bigger arrays, but unfortunately I think the weight of shipping that many drivers to the UK meant that the shipping costs rose substantially and then of course the drivers arent so cheap any more. In the end I was all a bit rushed and just grabbed 4 along with a pair of these:
http://www.madisound.com/catalog/product_info.php?products_id=1757
and these:
http://www.madisound.com/catalog/product_info.php?products_id=8312
again purely because they were there and cheap and I didnt have time to choose carefully unfortunately. I've never designed a crossover before and I doubt theres a crossover predesigned out there for those drivers so I suppose it will be a learning experience.
I'm a student and move around a lot and dont have the luxury of my own house to keep things in so floorstanders arent really an option as my speakers get moved quite a bit. I have Zaph's ZD5s for when I really want to enjoy my music (and they really do the job, once again, thanks Mr Krutke). They did however pretty much drain my speaker building funds so now I'm really just looking to play with different types of speakers as I'm sure each will have its own unique sound which I want to hear but have very little cash to invest.
That's why I want to throw together these OBs even if they don't sound fantastic.
I'm building a pair of FE127 reflex boxes to get a taste of full rangers, and thoses two reduced drivers from madisound should give me a chance to try designing a crossover.
Thanks for the tip on coating the cones. Not sure what I'll use but I'll probably give it a go. Might sound silly but is PVA out of the question?
As usual I'm overwhelmed by the amount support offered from the kindness of peoples hearts here and I hope in the not too distant future I can start to give back
http://www.madisound.com/catalog/product_info.php?products_id=1757
and these:
http://www.madisound.com/catalog/product_info.php?products_id=8312
again purely because they were there and cheap and I didnt have time to choose carefully unfortunately. I've never designed a crossover before and I doubt theres a crossover predesigned out there for those drivers so I suppose it will be a learning experience.
I'm a student and move around a lot and dont have the luxury of my own house to keep things in so floorstanders arent really an option as my speakers get moved quite a bit. I have Zaph's ZD5s for when I really want to enjoy my music (and they really do the job, once again, thanks Mr Krutke). They did however pretty much drain my speaker building funds so now I'm really just looking to play with different types of speakers as I'm sure each will have its own unique sound which I want to hear but have very little cash to invest.
That's why I want to throw together these OBs even if they don't sound fantastic.
I'm building a pair of FE127 reflex boxes to get a taste of full rangers, and thoses two reduced drivers from madisound should give me a chance to try designing a crossover.
Thanks for the tip on coating the cones. Not sure what I'll use but I'll probably give it a go. Might sound silly but is PVA out of the question?
As usual I'm overwhelmed by the amount support offered from the kindness of peoples hearts here and I hope in the not too distant future I can start to give back
valleyman said:
If you want to play around with crossover settings without spending any money, you can try using the excellent foobar crossover plugin at http://xover.sourceforge.net/
I'd have chosen the high Qts foster wideband drivers but madisound is finally out of them. My local surplus shop still has a bunch of them at $3 each but then again, the cost of shipping across the pond has to be considered. I doubt you're going to get much (if any) bass out of these in classical OB
Best of luck.
Hi all, sorry to revive an old thread but I have got round to throwing these drivers on an open baffle. In the end due to shipping costs I only went for 2 on each side so they arent really arrays but it has actually turned out quite fun. I use my pc as a source so I can give them plenty of bass EQ. Theyre on 10" wide baffles with kind of triangular wings at the back as legs so the bottom driver effectively has a wider baffle than the top. For this reason, I have decided to try coating the bottom driver and adding mass to give it some more bass oomph and I'm going to remove the dust cap from the top driver and install a phase plug to give the top end a little more sparkle and hopefully the 2 will complement each other quite well.
Unfortunately I cant ever see these being great speakers, but I have to say I'm bery surprised with how good they sound, especially since the pair cost a grand total of �£7 as I just used offcuts of wood I found in a friends garden.
Guess who wants some nice OBs now... I really enjoy the sound
Unfortunately I cant ever see these being great speakers, but I have to say I'm bery surprised with how good they sound, especially since the pair cost a grand total of �£7 as I just used offcuts of wood I found in a friends garden.
Guess who wants some nice OBs now... I really enjoy the sound
Thought I'd post a picture of them too. They actually do produce bass! Admittedly I have the bass EQd about 15dB up in iTunes to make them do it, but they do it nevertheless.
Without much thought to science, I decided that since the wings are wider at the bottom, that driver would take care of the bass so I coated the cone all over with a lot of PVA, twice in some attempt to add mass and reduce the Fs. I realise this isnt critical in OBs but as I said, not much science involved in this project.
I was also at my local hardware shop and found some little wooden "acorns" that are meant to go on the end of light switch pull strings. They were only 50p and I thought they might just work as some rudimentary phase plugs so I popped the dust cap off the top driver and have blu tacked the acorn onto the pole piece.
With some more use of EQ to even out those horrible response bumps, I really am genuinely surprised at how not bad these speakers sound.
I've had fun with them, and I think achieved the goal I set out for - to hear what OB speakers sound like and decide if I like it and the answer is most definitely a resounding yes.
Thanks again to those that contributed
Without much thought to science, I decided that since the wings are wider at the bottom, that driver would take care of the bass so I coated the cone all over with a lot of PVA, twice in some attempt to add mass and reduce the Fs. I realise this isnt critical in OBs but as I said, not much science involved in this project.
I was also at my local hardware shop and found some little wooden "acorns" that are meant to go on the end of light switch pull strings. They were only 50p and I thought they might just work as some rudimentary phase plugs so I popped the dust cap off the top driver and have blu tacked the acorn onto the pole piece.
With some more use of EQ to even out those horrible response bumps, I really am genuinely surprised at how not bad these speakers sound.
I've had fun with them, and I think achieved the goal I set out for - to hear what OB speakers sound like and decide if I like it and the answer is most definitely a resounding yes.
Thanks again to those that contributed
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