DIY Dome Tweeter ?

soundsgreat

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Hi,

After checking out various tweeters and having spent a fortune :annoyed: on them I have decided to take the plunge and build myself a dome tweeter on my own :D !!

Its not that they were totally bad (well some were :mad: ) its just that there absolutely no VFM proposition in any of them ! I've tried Usher,Scanspeak,Vifa,Peerless (Indian and Dutch) ! AFSIC all of them are poor VFM ( I see Some folks Sharpening their Daggers :p ) !

So this Idea came about and Am on the verge of building a Custom Tweeter !! I have got the source who will machine me all the parts needed ! I have already bought the Magnets (72MM) and stuff !

So what do you guys have to say ?? Share your thoughts :D !

Regards.
 
Yeah remember, the whole is greater than the sum of its parts.

PS: I hope you will supply your invention at VFM prices one day :)

Cheers
 
soundsgreat, best of luck!
as far as i can see, the scanspeak revelators are really very good, so i suppose you could reverse-engineer one of them-
let us know how your project goes!
suri
 
Hi,

Preciously the man I was expecting to bombard with the question first :ohyeah:!!

How are you staking your claim to be among such hallowed names?

??? If you mean how Am I comparing mine with them or how will it be compared ?? if yes then the answer is,Am not trying to claim anything !! its just fact finding mission of sorts which I've strated ! also if I were to stake a claim to be among them or on the same lines,then the whole point of me doing DIY is lost don't you think ???


Now coming to your queries,

what Fs and impedance you're shooting for, how much excursion, what levels of 2nd and 3rd HD, faceplates and mounting, dispersion characteristics, fluid versus not, recommended crossover points and suggested woofer mates. Also any special features - chamber design, rear venting (or not)

The Targeted Fs is around 600-800Hz ( think as crazy of me as possible ) for some specific reasons which Am in a liberty to discuss at this point in time ! The Imp of 8Ohm with a DCR of not less then 6 !! so any point above 1K should cool :cool: !

Am trying to keep a excursion of 1MM as its more then sufficient for a tweeter ( I've not seen many tweeters having an Xmax of more then .3 or so and some even less or none)

The 2 and 3rd HD will have to be measured coz as far as Iam concerned or I understand untill you have a sample ready and measure or use some XXX $ to simulate the exact results its of no use talking !! coz since this is a DIY and since this will be done in a machine shop where they only know to turn the metal to the need Dimensions and I will try to use some glue to bond it etc etc (every damn thing will matter when we start to speak of these things) ! I cannot say as of now what grade of MS results in what type of sound etc ( I mean you cannot predict the behavior on paper) !!also since Am not using any sophisticated SW to design I will have to work the other way round !! I guess you get the idea ! if not will try to elaborate it !

The Faceplate will be an 3MM Aluminum with 115MM dia ! the Dispersion angle and radiation is under scrutiny so will let you know once Am done with it ! but in general it will have almost 40+deg at the start of the dome unit

Mounting as in ??

Will try both ! first without the Ferro and then with it !!

Crossover Am thinking of 1st order !! the tweeter will be capable to handle this ! and I don't what other think,But Am person who believes that things has to be kept as minimal as possible which is why I have till date never used more then 2nd order in any thing I built !

The mating woofer is pretty much evident with the Aimed Fs !!

The Pole Piece will be vented and extended further beyond the bottom plate ! Am also planning to use Faraday ring ! but that has to be seen later ! No special chamber as some of the Vifa or the likes ! but as Am extending the vent I hardly see the need !!

You obviously know it's not a question of assembling parts, but designing from the ground up. So when you say 'I've already bought the magnets' I'm not sure what you mean.

Preciously otherwise every other guy with a ABC of electronics would've cooked up his/her own drivers and built a speaker making the Bigwigs of the game to disappear into thin air ;)!!

What I mean is in a layman's term the work has already started !! Not everyone in the forum are as Technical as we are right ??

Ok I guess I've answered all your quiers to the fullest :)!! if not please do ask !

Now here's what I'll tell you which you may have overlooked and not asked !

The voice coil will have venting throughout to aid in cooling and also in the taking out some resonance ( will be very imp since the aimed Fs is not typical ) and the material will be Alu (but let me see what all I can manage for this )

The Dome itself will be in all probability a Titanium,but I have some other types aswell like PEI,Poly,Silk,Fabric,Metal etc etc.....

The pole pieces will be of 3 and 2.5 MM (bottom and top) !

The Air Gap for the coil is around 1.5 (which is need for the desired Fs) !

A high density magnet (preferably F36 or so ) ! also contemplating on using 2 of them to increase the overall flux !

Working on various types of frames to mount to the dome unit ! some of it include GlassFiber (as in GF PCB),polycarbonate,ABS Plastic,Acrylic etc etc.. Am of the opinion this is also as much important as the other things !! again in this will have two types one the regular one which only is a little big then the dome ! the other which will completely cover the top plate or is of the same dia as the top plate !

Hmmm :eek: Thats all I can think of at this point in time !! anything missed out,has to be reminded !!

Regards.
 
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Hi,

OMG before I could finish my reply you guys have posted :p !!

Yeah remember, the whole is greater than the sum of its parts.

PS: I hope you will supply your invention at VFM prices one day

I don't what are trying to imply but if at all Am planning of making it commercially will certainly keep you in the loop :) !


Suri,
There's no doubt that they are among the best ! but at what cost :mad: ?? No offense but not everyone can afford it like you ! also I think they are ripping us off by collecting a premium on the brand then the actuall product !! cos if you see BOM of these units,it'll be marginally higher then the normal ones as this has a special motor design and stuff ! but if you see the pricing :rolleyes: well what can I say ??

o i suppose you could reverse-engineer one of them

I will certainly not do that !! I will learn the hard way,even if I fail at first attempt no worries but will try to comeup with my own theory or way of working !!

But will certainly take notes from these tweeters ! as you all know Am no Driver designer or even remotely close to one !!

See its like this,For all the guys with the question Why the heck do you want to reinvent the wheel ??

What I plan to do is to build a cost effective tweeter which will be on par with any damn commercial ones ( please bring on the wrath for having said this ) !! I very well know Am no driver designer and I don't have a fancy Lab and millions of $ to play with ! but thats the whole point ! If one can seriously try,he will succeed !


Regards.
 
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Sure soundsgreat,
and I can say this - PIONEERS ALWAYS GARNER RESPECT WHEN THEY SUCCEED!
and like you say, if you try hard enough, and are focused, you are bound to succeed!
Best of luck, and keep us posted
suri
 
Hi,

Cranky Thanks First off for the support and such that you are offering !! will surely ask if I need any !!

Now Please Excuse me for the following :p !

My first question was the basis for rejection of established brand offerings and the subsequent claim that your offering was superior.

Have you read my post properly ???:rolleyes:,if so could you please highlight or repeat it so that I can correct it or clarify or throw some light on it !!

In no part of my post have I said anything bout mine being superior or claimed a single damn thing !! So I request you to Kindly refrain from making such comments as this gives a wrong impression to others !!

So in a sense, what specific claims are you making, both in technical and marketing terms, that positions your offering above those from these vendors.

Again I absolutely have no idea/clue as to where you got this impression !! if have a knack of reading between the lines and make statements based on them,then Am sorry cannot help you ! but otherwise Let me Clarify,

I Have NO CLAIMS !! My tweeter is or will be a DIY effort which has some hopes of achieving certain things, whether it'll come through or not is another thing which I will talk at the appropriate time, Now is not the time ! Mine Might be the shittest/worst/most mediocre (please feel free to add on :) ) tweeter that has ever came out on this face of earth ! but even if its the other way/viceversa still its mine and I claim nothing !

What I said is,they offered no VFM (yes this I have claimed) and I will still stick with it !! to me a what I pay for and what I get in return should be equal or atleast justifiable this VFM to me (will not add anything else as its different debate altogether as to what constitutes to VFM for which individual) ! now what this means to others is of no consequence to me !! this is my personal view and Am entitled to one !!

that positions your offering above those from these vendors.

Similarly Who said anything about makerting them ??? atleast not me :p ! Am making this for my own damn sake,so NO Selling, No Marketing,No Nothing !!!

I've made this clear on second post replying to Gobble :)!!

Anyways Hope I've cleared the Doubts ;)!

Ok so thats done with Now lets get on with the business,

With large excursions like 1mm and 600Fs, you're aiming for a pretty large dome/VC which might then run into dispersion issues higher up the range, unless you make it concentric/ring-dome with two radiating surfaces (and end up with combing).

Well what you say might be true,But thats why I have devised some solutions for keeping VC small (as in regular 25MM) and still achieving the goal (may be harder then said :p but will give it a shot ) which I have mentioned in the reply ! one the second point yes it seems so,as one single dome unit may not work ! thats why I have a hybrid dome,its a titanium with silk !! the outer ring or the surround (like the one in a regular driver) is of silk with a roll (to freely move) and in the inner or the main thing is titanium ! so this though strictly cannot be called Dual Concentric but still somewhat works on the similar lines hence is opted !


This will help it mate to almost all midwoofers upto 7" without any issues, and should be fine with even 8 inch woofers and a slightly lower XO point for reduced power handling, as long as the distortion is not too much (below -40dB is normally good enough).

Well thats the Idea Buddy ;)! I want this dome to work with most of the midbass driver available so that I don't have to break my head with matching them and taming them a higher slope crossover and Blah Blah Blah.......

It will be much tougher to cross over low and maintain phase integrity across the band.

Well let me just check and see where I end up :p!

On excursion I would say 1mm is too much, even 0.5mm should be enough but I trust you will put in a few runs with both to see what kind of power handling you can get out of your speaker with both excursions, as well as distortion results. Again, I would be very happy with something that maintained its composure with about 30 watts @1.5KHz and about 50 @2KHz. More is usually not needed, I'm assuming your tweeter will have at least 88dB/W sensitivity.

Point noted let me see if I reduce the Xmax where will I end up with respect to Fs and overall SQ !! Yup most certainly will test it and share the results :) ! also as I earlier mentioned I have too many dome units to try and not all of them are capable of 1MM ! so its just a matter of changing the dome unit in the same motor and seeing the result ! as with the Sensitivity Am also hoping it to be in the same range of 88-90dB !

Are you planning quantity manufacturing or limited contract runs?


Last but certainly not the least, Once again, Sir I have no Plans to commercialise this as of now !!

Having said that I will most defiantly consider your request and offer you a pair to play ! But first let me have a successful run (as in complete ) of the prototype's with all the R&D's :D ! Then surely will let you know !!

Regards.
 
Hi,

Man you guys out did me again :lol: !

Suri thanks a lot for the comments ! Sure shall post the results and keep you guys hooked ;)!!

Unleash Thanks for the Link and the alberts quote :) !!

Regards.
 
Hi,

Mr Cranky Sir, First off please put aside your theory of stepping out of this thread !! That would only mean your are the touchy one :p !!

I will not try to reply point wise as it may lead to another confusion or misunderstanding (both of which are a strict NO NO to me ) !! let me just say this !!

I have no problems if you are anyone else asks any number of questions,Am anything but a touchy person !! so please.....

If I had problems I wouldn't have bothered to post this thread in the first place and wouldn't have answered to you and to others !!

What I was not happy was that you were giving an impression (to me atleast ) that I was trying commercialise or something like selling ! thats what I could read by the choice your words,but now since you've clarified ! rest I didn't have any problems then neither do I have it now !!

I will not utter a single word on the other things you've said in the post ;)!


Anyways I guess we have to put this behind and move forward !!

So I hope to see you in action again ! but still if you choose to stay out and not participate then I don't know what to say !!

Coming right to the point,

What I mean if Value for Money (The V & M) ! Ex of this ?? A scanspeak Relevtor at 250+ or so $ is absolutely No VFM !! not to me !

Ok now what I want to do, I want to build a tweeter at a reasonable cost say starting 1K to a max 2K which will either outperform (just a thought not a claim ) or equal the tweeters costing twice or more !!

I plain to make a pair obviously ! I intend not to waste or destroy a single piece (perhaps a tall claim but I shall prove this ) !! I have no such software and I have no plans to use them !! I rely on previous experience with the DIY and shall do it the same way !

As with the benchmarking,Very simple ;)! compare it with the already mentioned brands and see where it stands not with any fancy spec sheet and spice simulations and stuff, but with the real world results ! I will ask help in this regard,will call all the members to listen to this and give feedbacks ! and later plan to compare it one to one with others and see the result ! This may sound Lame or improper ! but thats the way I've chosen to do things !

Hope this clears all the confusion thats brewed here :cool: ! So what say ??

Again hope to see you in action with any or many more questions ;)!


Regards.
 
Hi,

Guys update time :D !

I have just bought some of the components required for the unit !!

The basic Metal plates ( precut round ones )

The Domes (various types)

Here's the pics of the same !

P1050481.JPG


The Magnets

P1050765.JPG


The Titanium/Silk Hyrbid dome ( Top View )

P1050775.JPG


Side Voicecoil View

http://lh6.ggpht.com...50778.JPG?imgmax=800

Bottom or upside down View

Rest in next....
 
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Here's the remaining stuff !

This is the PEI dome unit !

P1050760.JPG


Top View

P1050769.JPG


Side Voice Coil View

P1050772.JPG


Bottom or upside down View

As of now this is what has happened ! the plates will be turned and be ready in a day or two !!

Regards.
 
Hai Soundsgreat,

Not only you but your product will also be called by your name- SOUNDSGREAT. My advance congrats for your project.

Pl keep us posted about the project.

With regards,

N Murali.
 
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Hi,

Man its every DIYer's dream to be called such :p !

My Hearty thanks Murali for the support !! Sure will keep all of you posted on the latest happenings !!

So have obviously read today's journal ;)! this what happened ! in a couple of days the plates and other metal parts will arrive from the machine shop ! the moment it comes shall post the pics !

Guys please do participate and bombard with some idea's comments and such !! tech non tech doesn't matter,what matters is your participation :)!

Else the whole idea of me posting this thread is devoid :p!!

Regards.
 
@Soundsgreat - Just saw this thread. I have to admit most of what you said (at least the tech part) went over my head. Anyways wish you "all the best" and do keep us posted especially with pics. Hopefully, next time I'm in Bengaluru I will have the opportunity to listen too.
 
Hi,

Thanks Moserw :)!

I have to admit most of what you said (at least the tech part) went over my head.

Don't worry buddy neither did I when I was starting (though have to admit it way way back :p ) ! just keep reading such things you'll begin to understand ;)!

Anyways wish you "all the best" and do keep us posted especially with pics.

Absolutely,I shall document this project well not only to show you guys but also to show other skeptics and critics that this is no fluke ;)!!

As said earlier Am awaiting the machined parts to arrive ! once it comes then will post and take things forward !

Regards.
 
very nice pictures and a much awaited project shreekanth

quote says it all :
"to reach impossible heights , one begins with possible steps! "

A rear chamber MOD link I foundmod-link-on PE

hope to explore at my next visit :D
 
Hi,

Kaushik Thanks man :)!

The Rear chamber is somewhat similar but this is done in a very very different way ! The PE's Dayton tweeter mod is very very old and I have studied I don't know how many times :p ! I have also taken notes from B&W which is pioneer in such tweeter as they are one's who introduced these features in the tweeter with their Nautilus range (although started a very highend stuff,now even their low range products have a trickled down version of this ) Scanspeak and others !!

Please do so,as you know you are always welcome !!

And Ohh I forgot,Moserw you are also most welcome to drop in !! I totally forgot to add it in the last post :p !

Regards.
 
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That's great Sreekanth buddy!!!!! i shall drop in this weekend for a look.
All the best........


Regards,
Anil
 
Hi,

Guys its Update time :yahoo: !!

I have finally got the metal pieces machined and ready for action !!

Here's the pics of the same !!

P1050478.JPG


Top and Bottom plates

P1050482.JPG


The Center Pole Piece

P1050486.JPG


Center Pole Piece different angle showing the vent

P1050488.JPG


Mock assembly of the Pole Piece and Bottom Plate
 
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