| Mayday |
I'm going to use these Philips AD 706 6,5" Fullrange elements, quite modified.
Measured data:
8 ohms
Q=0.7
Vas= 17 liter (0,6cu.ft)
Sensitivity = 90dB
Fs = 70Hz
supposed to roll off at 18khz
They are dusty and dirty but in perfekt shape.
I'm leaning towards horns or dipoles, what du you guys think? |
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| Zen Mod |
depending of room and space you have;
try them on temp baffles ,then- if you think they deserve that,build bigger baffles with 15" bass helper and helper tweet ( if needed) ;
look at "beyond the ariel " thread
and- google for "lampizator" , then check his speaker pages
if you have no room for OB, find this :
http://www.sonido.hu/adat_pdf/DIY/DIY-MH-14-light3.pdf |
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| Mayday |
| quote: | Originally posted by Zen Mod
depending of room and space you have;
try them on temp baffles ,then- if you think they deserve that,build bigger baffles with 15" bass helper and helper tweet ( if needed) ;
look at "beyond the ariel " thread
and- google for "lampizator" , then check his speaker pages |
The speakers I'm building are for my brothers daughter, it's her first stereo I'm putting together. For ampification I'll use LM3886 chipamp.
My brothers budget for this build doesn't allow for further drivers.
Do I understand you correct that you suggest open baffle design?
I use that myself with Dayton 15" IB, Seas P17RCY and B&G NEO8. |
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| Mayday |
| That horn design you linked to looks intresting, do you think this driver is suitable for that? |
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| Zen Mod |
| quote: | Originally posted by Mayday
That horn design you linked to looks intresting, do you think this driver is suitable for that? |
even if not completely adequate - and you can find out only building it- it will be miles ahead any boxie box you can made for it.
all that - if that driver is anywhere near old good AD Philips series.
anyway-little girl will be thrilled with completely unique spks ;)
now-serious- good horn construction are way more forgivable to various driver than closed or BR boxes.
at least for my limited knowledge |
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| Mayday |
These drivers are Philips AD 706 but modified.
Thanks for the advice that horn looks really intresting. |
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| Mayday |
After talking to the girl that is going to use these speakers, she was leaning towards OB design, since she likes my dipoles.
Question is, can these drivers alone on an OB reach adequate listening volume? Not Very loud, just enough for everyday use in an apartement. |
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| Geoff H |
Mayday, would you believe I am currently working on some 6" Panasonics, with a Fs of 76Hz, on little OBs. The idea was to extract as much sound from these as possible.
OK, they won't shake the floor, but do go quite low for what they are.
The size of the baffle is 460mm high, 300 wide, with sides, 165mm at the lower end, tapering to 118mm at the top, (to be reduced) and a full width top shelf of 76mm.
All made from recycled MDF. I started with just the baffle. Played with different sized wings, to bring the bass up. I have lost a bit of sound stage, that's why I am trimming down the sides. in my case, a bass helper will fix the bottom octave or two.
I would give the back of the cone 1 coat of PVA, the whizzer 1 coat, front and back, the area behind the whizzer a coat, then 1 more coat over all the front of the main cone.
If you have some bitumen paint/sealer, some around the perimeter of the whizzer kills of some edge resonance. A light coat on the roll surround will raise the Fs a bit, which is OK on the small baffle. Mine started at 70Hz.
She will be pleased. I have passed on a few tweaking experiments to younger folk.
Geoff.
Edit: Hey Zen, they are old Philips. Not old enough for alnico though. |
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| Mayday |
| quote: | Originally posted by Geoff H
Mayday, would you believe I am currently working on some 6" Panasonics, with a Fs of 76Hz, on little OBs. The idea was to extract as much sound from these as possible.
OK, they won't shake the floor, but do go quite low for what they are.
The size of the baffle is 460mm high, 300 wide, with sides, 165mm at the lower end, tapering to 118mm at the top, (to be reduced) and a full width top shelf of 76mm.
All made from recycled MDF. I started with just the baffle. Played with different sized wings, to bring the bass up. I have lost a bit of sound stage, that's why I am trimming down the sides. in my case, a bass helper will fix the bottom octave or two.
I would give the back of the cone 1 coat of PVA, the whizzer 1 coat, front and back, the area behind the whizzer a coat, then 1 more coat over all the front of the main cone.
If you have some bitumen paint/sealer, some around the perimeter of the whizzer kills of some edge resonance. A light coat on the roll surround will raise the Fs a bit, which is OK on the small baffle. Mine started at 70Hz.
She will be pleased. I have passed on a few tweaking experiments to younger folk.
Geoff.
Edit: Hey Zen, they are old Philips. Not old enough for alnico though. |
I'm thinking of a baffle size of about 1,5x1m or there around.
A few questions; what's PVA, and what's wizzer? |
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| Geoff H |
PVA = Poly Vinyl Acetate = white wood working glue. Others use Puzzlecoat and or Damar. Dave at Planet 10's a guru in that area.
Whizzer = the little cone or tweeter cone.
Baffle size. Bigger is better. |
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| Mayday |
| quote: | | I would give the back of the cone 1 coat of PVA, the whizzer 1 coat, front and back, the area behind the whizzer a coat, then 1 more coat over all the front of the main cone. |
If I understand you correctly, one layer on the back of the cone, one layer on each side of the wizzer and one layer on the frontside of the cone. Can this be done without removing the cone from the basket, never done that. |
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| Geoff H |
You got it. Actually you end up with two coats on the front of the main cone under the whizzer. This stiffens up that area to boost the top end a little.
Be patient treating the back of the cone, working under the basket. Avoid the surround, spider, and leads. Artists brushes are fine for this. You could even have your niece involved with that. |
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| Mayday |
| quote: | Originally posted by Geoff H
You got it. Actually you end up with two coats on the front of the main cone under the whizzer. This stiffens up that area to boost the top end a little.
Be patient treating the back of the cone, working under the basket. Avoid the surround, spider, and leads. Artists brushes are fine for this. You could even have your niece involved with that. |
Just having a hard time imageining plain wood glue to work as a coater....
What's in the ones selling for a pretty penny then? |
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| Geoff H |
I don't know. I use wood glue and craft glue. The craft glue is thinner than the wood glue. You can dilute with acetone.
It does bond all the surface fibres, giving a cleaner, better defined sound. I have just done a head count. There are 9 drivers here that have had the treatment.... |
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| Mayday |
| quote: | Originally posted by Geoff H
I don't know. I use wood glue and craft glue. The craft glue is thinner than the wood glue. You can dilute with acetone.
It does bond all the surface fibres, giving a cleaner, better defined sound. I have just done a head count. There are 9 drivers here that have had the treatment.... |
I'll dilute the wood clue a bit then i think since that would mean easier application I can imagine.
Any tips on how to get dust and partikels of the cone before coating it? |
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| 4fun |
Hi Mayday,
It looks to me that coating has already been applied.
Have you listened to the speaker and concluded need for coating?
To me it seems rushed to coat them before doing anything else. |
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| Zen Mod |
| quote: | Originally posted by Mayday
I'll dilute the wood clue a bit then i think since that would mean easier application I can imagine.
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dilute it to be almost as crappy yogurt ;)
| quote: | | Any tips on how to get dust and partikels of the cone before coating it? |
why-leave it as reinforcement ......... :devilr:
use soft brush for cleaning |
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| Mayday |
| quote: | Originally posted by 4fun
Hi Mayday,
It looks to me that coating has already been applied.
Have you listened to the speaker and concluded need for coating?
To me it seems rushed to coat them before doing anything else. |
I'll look closer at them, no need to coat twice... |
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| Jaap |
I have 2 twelve inch Philips full rangers somewhere in the cellar. Anyone aware of a good design for these ?
I also have two philips "bombardons" bassspeakers, but that is a different story |
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| Zen Mod |
| quote: | Originally posted by Jaap
I have 2 twelve inch Philips full rangers somewhere in the cellar. Anyone aware of a good design for these ?
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digg them and look what type they are;
but I'm almost sure that you'll receive answer (at least from me) that they're good for nothing,and I'm generous to give proper disposal service for them,if you pay shipping............ ;)
I saw several projects on net for them ..........
| quote: | | I also have two philips "bombardons" bassspeakers, but that is a different story |
bombardons?
:confused: |
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| Zen Mod |
| quote: | Originally posted by Jaap
:smash: |
you know that I hate ya!
:clown: |
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| Mayday |
| Baffle size might get as big as 175x160cm....that should be enough. |
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| Geoff H |
Yeah, they might be treated. It didn't look that way to me, esp the whizzer.
Edit: Head count went to 14 including the tweeters in the cupboard. Including those that are in new homes, none have gone down in performance. |
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| Mayday |
| I'll take some close up photos tomorrow. |
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| 4fun |
Hi Geoff H,
Agree, the whizzer looks clean and free of dust. |
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| Mayday |
| I'll clean them up tomorrow and take nice closeups so that you can help me determine if they need coating. |
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| Geoff H |
Just to give you an idea.
Before I started. I noted that most of the travel was in the inner rib, and the insects had been at this one! Note the paper cone. |
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| Geoff H |
| After treating the surrounds, the travel was spread over both ribs. Started with mineral turps, then bitumen. Taking the bitumen onto the edge of the cone helps with edge resonance. |
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| Geoff H |
As they are now. Treble has come up, no tweeters required. Next step is to bring it up more, then spread the beam with a phasing plug.
No more hair on piano or acoustic guitar. Transients are clean and sharp. the lower mid / upper bass nice and fast.
Those Philips have greater potential, I think. If the cone has a plastic feel to it, I would say it has been treated. To the best of my knowledge, Philips of that vintage were all moulded paper.
Geoff |
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| el`Ol |
| The low Vas lets me think about BIB. According to my simulations Qts 0.6 is still O.K., so maybe even 0.7. |
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| Mayday |
| quote: | Originally posted by el`Ol
The low Vas lets me think about BIB. According to my simulations Qts 0.6 is still O.K., so maybe even 0.7. |
What is BIB? |
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| Mayday |
| Intresting, how do I calculate dimensions to fit my drivers? |
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| Scottmoose |
Good question. As we don't have many parameters, we'll have to SWAG it.
I'd do an inverted version, that vents near the floor. Set line length to 96in, Zdriver to 40in. Probably use Sl=6.5Sd to create an acoustically large pipe. Vas isn't too high, so I reckon that should be sufficient (8Sd is roughly what GM says the old Altec Nomographs suggested for a 1/2 wave So=0 pipe). Then damp it to suit your room / taste. Welcome to the world of tradional enclosure design. ;) It should work OK though, with some tweaking. |
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| Mayday |
Is the opening supposed to be 2 - 3 times the size of the membranearea? Could someone fill me in on this since or set me straight because I will also need to calculate measures for one that is to be a center channel in a hometheatre system.
For the center I'll use 2 TangBand W4-657. |
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| Mayday |
| Please help me with this last part of the design, only thing left before ordering wood and start working. |
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| Zen Mod |
| quote: | Originally posted by Geoff H
After treating the surrounds, the travel was spread over both ribs. Started with mineral turps, then bitumen. Taking the bitumen onto the edge of the cone helps with edge resonance. |
Geoff........can you look at http://www.diyaudio.com/forums/show...threadid=100337
and say what you think.......and can you also tell me what mineral turps you use before bitumen.........."bitumen" is a stuff used as primer in tar laying business? |
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| Mayday |
| Bought some damar in case they need coating. |
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| tinitus |
Be carefull with "bitumen" - I use the same stuff, mine is called "Isopunkt"
I thin it with "xylol"
The point is that it dries over a VERY long period of time, months or even years - so it takes some patience
I have discouvered that imediately after coating you may get a very nice crisp mid and top - but if coating is too thick, it turns rather hard, and the sound may become dull
But its very good effective stuff indeed :) |
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| Mayday |
| Does damar need to be thinned? I'm guessing I should apply it as thin as I can? |
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| planet10 |
| quote: | Originally posted by Zen Mod
[ll that - if that driver is anywhere near old good AD Philips series.
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I'm in late to this thread .... hope i'm not repeating something that is said in the next 4 pages...
What vinatge is that unit... except for the whizzer it doesn't look much like any of the Philips i'm used to seeing, but as Zen Mod says if it is anything like the ones from 70s, early 80s it should do well on an OB...
what wood did you use for the phase plugs?
dave |
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| Mayday |
I didn't make the phase plugs, they were made by previous owner.
I believe they are from the 70 - 80's hard to tell because they are in such good condition. Model is AD 706. |
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| planet10 |
| quote: | Originally posted by Mayday
Does damar need to be thinned? I'm guessing I should apply it as thin as I can? |
The stuff i buy at the art store is already mixed up... i've been using it on whizzers to good effect, but i hesitate to use it on the main cone -- i prefer to use puzzlecoat (a PVA that remains a bit more flexible than wood glue)... http://www.t-linespeakers.org/design/tweeks.html
i thin it until it is runny, and on a full range use 2 (or maybe 3) coats on the front-- using almost as little as possible. If i wwant to significantly stiffen the cone, i'll also do the back... you end up with a poor mans sandwich cone -- but in a full-range this isn't always the best thing, since the cone needs to flex to get decent HF performance. Too much and you can turn a FR into a midbass.
You can't really tell that the cone has been puzzlecoated in this one, but you can see how the damar has changed the colour of the whizzer (it used to match the surround) |
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| Mayday |
| I bouht my damar in an artstore. I'll just coat the wizzers to begin with. |
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| planet10 |
| quote: | Originally posted by Mayday
Model is AD 706 |
I've run across lots of AD7060 (with octanganal basket and brown main cones) but not these...
dave |
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| Mayday |
| A bit of the label has been torn of the box, all I can read is Philips AD 706 60-18000hz 25W |
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