Stuck in a 3 way project, diy speakers

[oszkar]

Stuck in a 3 way project, diy speakers:

Having enough of the old and constricted sound after several amps and pair of speakers I decided since owning some components and getting some more allong the way to build a pair of speakers but parameters detaining partner that helped me messure the drivers and plotted the xo diagram I will attach a picture of later on bailed for lack of time and it's own bussiness plans. Sadly I do not have the readings of the omnimic for all of them but as said I will put all I have here ind hopfully get out good with a little bit of my knowledge too put in to the conception.

 

[oszkar]

BTW. I have the coils for them, the 100uf, 10uf, 6,8uf caps all polarized and at different voltages all above 160V, and the one I am missing is the 82uf capacitor. Should I buy one two of those starting electric motors ones? Drivers are Beyma 6B30P Mid Bass for mid freq, Beyma 2030T for tweeter and Pioneer 25-717F this one I remember from the TS Small messurings it went as low as 37Hz. Cutting frequencies are 400 and 2000hz for these speakers.

 

[oszkar]

One more thing, for now my caps are all polarized, next year since I have reached my budget I will buy the Janzen caps.
Until then can anyone help me with the + and - positioning of the components? Thanks!

 

[jplesset]

Polarized caps will not work in a crossover unless you double-up and use them back-to-back. Meaning +- -+ or -+ +- Polarized caps depend on having voltage across them and never reversing that.

 

[oszkar]

So that means 100uf will become 200uf?

 

[eriksquires]

Oskar, sadly no, when you wire caps in series you divide. So 2x 100uF caps in series = 50uF. Inductors and resistors add. 🙂

There are some very inexpensive film caps I'd use instead. See about Cornell Dubelier, Bennic and Dayton, at least for the tweeter and mid.
Next up in prices is Axon (cheap version of SCR/Solen) and then Mundorf MKP which I like a lot for the price.

Double check your mid-range though. 100uF seems very high.

Do you have impedance and acoustical offset measured for each driver as well? If not, you are not ready to buy yet. 🙂

Best,


Erik

 

[oszkar]

They were measured with omnimic individually at 1m distance and the TS for the bass with an usb device. There has been a mistake in the schematic as I understood and that was: for these caps values the 2,5mh coil should have been 5mh in the picture above. I have only a 2,5mh coil and since no contact could have been established with my guide through the project I will say the last phrase heard from him '' the values of the caps should be instead of 100 - 50uf and instead of 82 - 41, basically half ''. In this manner the xo points will be 400 and 2000hz. If 100 and 82uf is put in practice with 5mh coil the xo points will become 200 and 2000hz. For the highs and mids will go with Janzen Crosscaps I think.

 

[eriksquires]

Hi Oszkar,

OK, good so you have good FRD and ZMA plots. How did you set your acoustic offset? 🙂

Best,

Erik

 

[oszkar]

I am not so familiar with terms in the mater but that might be the measuring all drivers or between the drivers to check for sudden differences between mids and highs?

 

[oszkar]

I just want to start them up that's why I am asking double up what would mean and how would all come on them. in October I will redo the xo's with the new 5mh coils and the np caps if not necessary now, untill then I would listen to them and have time to finish the fronts an the mount of the speaker grille. All the caps I have at home are polarized and as I got hold of a new amp plus had to pay for the enclosures and drivers and coils, paint and all the other accessories for them goldened banana female plugs, 2,5mm Monitor cobra cable and a little of everything else.

 

[eriksquires]

Hah, I knew it. Please see my blog post here....

Best,

Erk

 

[oszkar]

Ok! Thank you! Read it, and I went through the steps tuning will be made further as next mic measurements are made. The tweeter was the only one that was louder at 95db but will be attenuated with a 8ohm variable resistor or an Lpad. A tweeter will need other values than in the schematic because it is louder. Anyway I am buying in the end the Bipolar caps as I found a supplier here in Romania and is in the next town and not here this is what bugs me. I am attaching a link with the more budget series of what I found help me choose them as I expect they affect impedance. Will go for bass/mid for up to 6€ components and up to 4€ for tweeters. I have to get 2 coils that are 5mh aswell so will opt for decency upon my decision this time. All my drivers are 8 ohm. If I missed something please point it out! 🙂 AUDIO ALCHEMY

Hyperlink is:

http://www.audioalchemy.ro/filtre/condensatoare/Capacitors.xls

 

[oszkar]

BTW If all caps are BP, it won't matter how I place them on the XO, and the coils plus resistors they too do not matter how I place them cause they don't have a + and -?

 

[eriksquires]

HI Ozkar, right, coils and resistors have no direction. Um, Axon or Bennic are your best choices, this being your first speaker, they'll be among the cheapest film caps. 🙂

Mundorf MKP or Clarity ESA are the next stage up. I have no experience with Jensen caps.

ONe thng that will matter is the axis of coils. If you have more than one coil you want to make sure they do not share the same center axis. The magnetic field is like a donut, and they can induce signal in other inductors.

 

[oszkar]

About the coils, I have read earlier, that being last week one stays flat, one horizontal, the next one flat again (with the hole of the formed coil facing the ceiling), right?

 

[eriksquires]

Please see my blog post here.... 🙂


Best,


Erik

 

[sesebe]

Hi oszkar,

Can you post your FRD and ZMA files?
For C3 I sugest you to use something like this: Condensatoare | Transfer Multisort Elektronik s.r.l. - Componente electronice
Bipolar caps in tweeter section is not a good idea.
For mid section you can use propilen type capacitor for motors. Are working verry well there, the only problem are the dimensions.

Good luck!

 

[oszkar]

Erik, thanks once again. Since I got to audio alchemy site I will supply myself entirely from there. No metal layers will come underneath for the copper and aluminium part that could bend modify the values of the caps or the coils. Got some pressed wood dust laminated 3mm sheets. I found one mail that said when taking care of the project, that the mid will be inverted 180 degrees - to + and the tweeter and bass are going to be connected normaly + to +.

 

[oszkar]

I have looked on the TME site too, will go there too if something does not show in the list that shows the necesary components. Thanks!

 

[turk 182]

not sure if it's true but i've heard that coil direction can make a difference (paying attention to the fact that the lead that goes to the inside (start) of the coil can make a difference sonically if reversed)