I've been looking for different tweeter and loudspeaker for a while and i was looking at their Frequency response curve. I'm not sure how reliable they are but i got pretty satisfied with what i found ( the curves )

I know little in electronic part for audio and i will need to put a crossover in my box for my tweeter/6.5'' split . The crossover should be at 2Khz for 200w each speaker , 8 ohm.

I'm trying to find the proper part OR the proper person that can build a clean one for me ( The crossover ) .

Also, i dont understand how to calculate the inside dimension in liter of my box with the infos of my 6.5' speaker.

Its not clear, i found a huge mathematical sentence that i dont understand.

I found somewhere else a random number of 13.64 lts for a 6.5'' driver ....how random is that nmber ? haha

If anyone can help me with those 2 problems ( Crossover + dimension ) i would really appreciate.

Thanks a lot.

 

Try that for calculation

http://www.mh-audio.nl/ClosedBoxCalculator.asp


And these for information (they have more links for reference on their sites)

http://www.hardwareanalysis.com/content/article/1789.9/build-your-own-10-inch-subwoofer/
http://www.home-speaker.net/speakercrossover.html

 

If you just buy a chassis an put it in a box chances are very low that they will make good monitors. A speaker is just a single part of a electroacoustic system that needs to be tuned very well to sound good.
And there's a lot more to speakers than just size and frequency response. You will need to use some of that info when constructing your monitors.
To calculate box size, start here:
https://en.wikipedia.org/wiki/Thiele/Small

If you don't want to go through that, you may be better off not going DIY.

Another option: Check the website of the speaker manufacturer. They often provide sample projects.
Or just check DIY forums for proven projects.

 

It needs a lot of experience, measure tools and time to build a proper passive speaker. And even if you have all that you might end up spending more money on an passive monitoring system than buying an active one that would sound better. I built 3 different speakers from guides of a popular diy-speaker magazine for my livingroom, and guess what, now there are active speakers of a well known brand. A lot of hassle and money.
To get your thing going you might spend about 60€ for the crossover (copper became expensive). For a complicated one with passive eqing and bells and whistles you can easily end up at 100-130€ (per speaker!). Then the wood-job, the connection terminal...
But if you wanna do this for the joy of building something and learn, go for it, but be warned, it is a frustrating long, long journey.
Best way to start is to go by a diy loudspeaker project of a magazine or a diy freak with a blog. if you already got (one) chassis you want to use, try to find projects that are using that. What tweeter and mid/low range did they combine and why, have a look at their crossovers and get to know what the parts do.

 

Last edited: Jul 14, 2016

Back in the day I've been trying to do everything DIY. I have and use nothing of that DIY stuff now.

Especially regarding speakers there's so much physics and maths involved I don't think you want to go there. It is very complicated to make your own speakers that sound good, and the box/chassis is of utter importance, not the drivers. In many aspects it is easier to make Urei and SSL compressor clones than PMC or Dynaudio clones, and it can be pretty costly in the end.

But on the other hand there is the fun aspect to DIY... and it makes your brain work, you can learn a lot about various audio, acoustic and electrical things. It is certainly useful to know how to do stuff [e.g. solder].

 

Thank you for your answer.

I followed the instruction with my best common sense and my 0 knowledge of what i'm doing.

Here's the info of the drivers :

Tweeters:



Mid range :




Here's my calculation ( I took all the info from the mid range driver because I understood tweeter dont need no enclosure ....or am i wrong ? )

 

Here's the result:



Is it just me or are they telling me to build a 142.20 liters enclosure for a 6.5 inch driver ?

Makes no freakin sense or I'm missing something ( or everything on that matter )

 

Yes, i want to do this to learn it by myself ....to actualy see the result and experience the failure of that kind of project.

But i want to put my all into it.

I mean, i dont want to build a rocket.....I just want to put decent drivers in a properly dimensioned enclosure with a decent crossover inside.

All of that with the knowledge that I have + the clear and simple info people will be willing to share along the way for me to understand a thing or 2 before i start cutting my MDF sheets and using my tools to carve ome groove to glue it all together.

I can build an enclosure , it wont be a problem, but i cant build a crossover....my welding look like shit and i dont have a single clue of howto look for decent component of a crossover .....so i prefer to buy a passive crossover that is proven to be decent for references monitor with the input that i have.

I dont want to do a DIY kit....i want to do my own scrapy project with the help of nice person that will be kind enough to give me clear and simple guidance through my project.

 

That page gives you the frequency response in real time after you enter the values.
It always says 142.20 when you land on it.



Dickason's Design Cookbook. Invaluable tool if you really want to do this.

Formulas and a Glossary

I blow speakers up. I don't really build them.

 

Last edited: Jul 14, 2016

Thanks for all those infos !

And we're about to be 2 blowing speakers up haha

 

For everyone that want to build pasive speaker, which is intended for studio, but at the same time you can use it as home hi-fi speaker, i recommend this one in the past. But don't know how is with driver availability these days. Is in Croatian language, but anybody can read out needed driver, crossover and dimensions. Most hard thing to do is probably box and you need to use plywood. 20 cm is recommended, because box need to be very sturdy.

http://www.audiopuls.hr/diy/chameleon.html

 

Plywood is not as dense as MDF so plywood resonate more....

 

Don't know about that, but designer who construct and design them was very explicit about using plywood in his design. And i can a assure you he know his business. He made some world class audio gear.

 

Thats weird.

First time I hear that.

 

If you need something cheap,music store sells a pair for 59 euros,rated very good.
https://www.musicstore.de/de_DE/EUR/Fame-P-62-Studiomonitore-passiv-/art-REC0006447-000

 

"decent" is the problem, i'd say i would consider myself as experienced, i know what cone breakup is, know how to read waterfall diagrams, did my first diy project 20 years ago... and i would not design it from scartch as i am WAY to unexperienced to get it to be decent in the end. A practical solution for your actual thing might be to get a pre built crossover from ebay or whatever. something with a crossover frequency of 2500 at 8ohm might at last work (didn't say anything about sound). Then use a passive tweeter attenuator to level the tweeter.
I'd say the wood you use (or don't use) is not important at this level. Stick with the mdf, as it is cheap and as you say does not resonate.
the common 2 or 3 way loudspeaker is always cheaper pre built - take that 60€ speaker from van steyr, impossible to just get the chassis for that price. It's a little different with exotic stuff the industry won't supply you with. large horn systems, truck like subwoofers, flat surrounds, omnidirectional stuff... but that again, why did this and that not become mainstream? maybe it just looks cool and sucks anyway...

 

Last edited: Jul 14, 2016

The practical solution sounds good to me.

Could you point me out to a very good passive crossover at 2,5Khz 8ohm ? I'm trying to find pre built crossover and all i find is some random cheap ass crossover that I dont know much about. Maybe a website where there is all sort of good quality part to build reference monitor.
In the worst case, i'll end up with a pair of speaker for my patio haha.

Also, you montioned an atenuator for my tweeter....why would i need that if both are 200 watt 8 ohm and the frequency curve follow on the 95 to 97 db spl ...i mean, i saw the KRK curve and those ''reference monitors'' have an horrible curve compared to what i might be able to build with the drivers i found , no ?

Oh and by the way, If i said it didnt resonate, thats not what i meant. I read somewhere that MDF is more compact then any other wood material and essence ( maybe excluding eben ). But i saw that Oak is less dense then MDF and for that reason it resonante more then MDF.

Anyways, thanks for your input. Really appreciated.

 

As I've built 9 Hi-Fi and 5 PA speakers, and the last attemps ended up not too bad actually, here's a few tipps I can give you from my experience.

• It's good that you stick to the idea of building your own speaker. You won't learn much if you give up before.
• MDF, plywood etc all do resonate more or less, just at different frequencies and also depending on wood thickness, but as long as they're not too thin, the impact on sound is much, much lower than what speakers you use, what crossover you build and choosing the cabinet design.
• Never buy a pre-fabbed crossover. Every speaker combination needs a different one, sometimes you even have to use slightly different crossover frequencies for LP and HP, depending on the speaker's frequency responses. You can't even decide what type (6/12/18/24dB etc.) to use before you know the speaker chassis.
• Don't buy speaker chassis before you know the TSP (Thiele/Small parameters) of the bass chassis and at least the frequency response of all chassis you want to use. There are many combinations on the market that would hardly combine well, so do your research first.
• If you don't know at least QTS, FS and VAS of a bass chassis, then simply don't buy it!
• What cabinet size you'll end up with is largely dependent on the TSP, so if you want a box of specific size, you're again limited in your choice of bass chassis. Make sure to do example calculations or if you're unlucky, you'll end up with an 8" monitor that needs the enclosure of a typical household fridge in order to give you the expected bass response ;)
  
• Closed and bass reflex speakers for the same bass chassis have different sizes! Bass reflex will be larger for the same chassis but will give you better (lower) bass response.
• I have always used the freeware "WinISD" from linearteam.dk with good results. It is especially useful to be able to drag two cabinet parameters simultaneously using the mouse and watch the resulting speaker response. It can even do Band Pass calculations in case you need a real bass powerhouse for a specific low frequency range.
• Low-cost speakers chassis have become better. There's still a lot of garbage out there, but check out chassis rewiews in forums and diy magazines. Especially later chinese ones have surprised me again and again.
• Don't under-estimate impedance correction. No chassis has a flat curve, and if the peaks are at a bad spot, your crossover (and the sound) won't do what you intended
• You can even equalize hills and valleys in the frequency response, as long as they're not too drastic. Like a parametric equalizer but in "hardware" using coils, capacitors and resistors. Note that this is not cheap and rarely better than investing the money in better chassis.
• A treble attenuator pot can be an advantage over a fixed resistor network because depending on how you set up the speaker, the tweeter level might easily need some adjustment. It's not always possible to keep the perfect listening angle to the speakers, and tweeter level is very angle-dependent with most tweeter chassis.

Good luck!!

 

Last edited: Jul 15, 2016

@fiction

Thank you for your answer. This will help me a lot