Thank you,
As i have the 4 TCFD9 drivers and about to mount on the boxes( which i have not glued pieces yet) was wondering if for nearfield listening position( 3 or 4 ft way) in my desk with subwoofer under my desk( to max 140 hz i beleive), .. if a tweeter is needed, or just toe them in to my listening position and if i should mount the drivers symmetrically on top of each other or non symmetrical as you suggest. i will be putting the cap between the lower and upper driver. should i make the while thing open or continue the bottom closed to have a bit of body or mid bass as i like rock too? should i put another cap before the first driver(?? value) to cut off lower frequencies to the both drivers in each speaker so they are more relaxed or go as original design, full range bottom driver, upper with the.20 uf cap? as i'm about to do this, might as well take your cues to improve the design for desktop application...Thanks again.🙂
As i have the 4 TCFD9 drivers and about to mount on the boxes( which i have not glued pieces yet) was wondering if for nearfield listening position( 3 or 4 ft way) in my desk with subwoofer under my desk( to max 140 hz i beleive), .. if a tweeter is needed, or just toe them in to my listening position and if i should mount the drivers symmetrically on top of each other or non symmetrical as you suggest. i will be putting the cap between the lower and upper driver. should i make the while thing open or continue the bottom closed to have a bit of body or mid bass as i like rock too? should i put another cap before the first driver(?? value) to cut off lower frequencies to the both drivers in each speaker so they are more relaxed or go as original design, full range bottom driver, upper with the.20 uf cap? as i'm about to do this, might as well take your cues to improve the design for desktop application...Thanks again.🙂
Is tweeter needed? Well, that is up to you. Have you read my first post? Answer is right there. I built Nola and I did not like the result. Even you use cap on one TC9, still you got two drivers projecting heights...is it ok with you? Only you can know. For me that is big no-no. So I built MTM, hence this thread. You can built what I offer, as close as to what I described, or you can built Nola, that is up to you.
It seems to me that an open back enclosure with sides all around would have substantial resonant cavity effect on the rear output... regardless of how much padding you put in the box. Was this not a problem?
If you mount 2 TC9's in the same box, and put a cap in series with one of them, you will have significant phase cancellation issues, because reactive elements (caps and coils) cause time shift or phase shift (same thing). You will have created a comb filter mechanism. That only works if you also put a coil in series with the other TC9 (for a full crossover network). But that would be foolish too. If you're going to put 2 TC9's in the same box, I'd wire them in parallel (I hope you bought the 8 ohm versions), and add a tweeter (the ND20 twtr is very good) and a crossover that has a crossover frequency at about 6kHZ. And I don't recommend an open baffle enclosure. They require substantial active EQ to work right, or you'll have very little lower mid and bass.
If one puts a bipolar electroytic capacitor of say 160 uF to 200 uF in series with the parallel combination of the TC9's that should trim off the low frequency response and help to alleviate the cavity resonance produced by the open back cabinet.
You would have to experiment with the capacitance value in order to get the desired result though. It's worth a try.
C.M
You would have to experiment with the capacitance value in order to get the desired result though. It's worth a try.
C.M
Simple answer is no. I see no such thing on fr response. I measured response numerous time while I was optimizing crossover. No resonant cavity effect. I have no stuffing in the back, its fully open.
I was meaning to ask you about that. I don't have any in mine either. Bottom line - it just sounds good to me 😀
Where are you finding inductors so small?
PE's smallest is .54mh.
Online, i had trouble finding some.
I guess due to hi frequency, the coil is tiny.
I was hoping to try with cheap stuff, then measure and try more expensive stuff for giggles...
I already have tc9's in a "nautaloss" box.
Tweeters wont fit, so am going to try this setup in another enclosure. If all works well, might try the mtm with nice woofers and dsp for a nice 3way monitor.
If this sounds as good as you say, and i love my "nautaloss" sound (with sub @ 200 hz), then i have high hopes in trying this out!
PE's smallest is .54mh.
Online, i had trouble finding some.
I guess due to hi frequency, the coil is tiny.
I was hoping to try with cheap stuff, then measure and try more expensive stuff for giggles...
I already have tc9's in a "nautaloss" box.
Tweeters wont fit, so am going to try this setup in another enclosure. If all works well, might try the mtm with nice woofers and dsp for a nice 3way monitor.
If this sounds as good as you say, and i love my "nautaloss" sound (with sub @ 200 hz), then i have high hopes in trying this out!
This is what i would recommend...0.2mH
Dayton Audio 0.20mH 16 AWG Copper Foil Inductor Crossover Coil
Dayton Audio 0.20mH 16 AWG Copper Foil Inductor Crossover Coil
Hahaha
My dumb *** clicked on "iron core".
That is why i didnt see the smaller ones.
Before you responded, i found the proper ones. 😀
Thanks for quick response.
So, go with the .20mh?
And do you have a preference between .33 and .47 uf cap?
What type and brand?
I was going to get a cheap dayton 1 or 2% foil cap, but if you have a recommendation or prefer metalized, i'd be glad to hear it.
I am not experienced at designing crossovers.
But i do have measuring gear and will try to have some fun measuring in spring...
I have pcd7 and hope to design a basic crosover in the future.
Thanks.
Todd
My dumb *** clicked on "iron core".
That is why i didnt see the smaller ones.
Before you responded, i found the proper ones. 😀
Thanks for quick response.
So, go with the .20mh?
And do you have a preference between .33 and .47 uf cap?
What type and brand?
I was going to get a cheap dayton 1 or 2% foil cap, but if you have a recommendation or prefer metalized, i'd be glad to hear it.
I am not experienced at designing crossovers.
But i do have measuring gear and will try to have some fun measuring in spring...
I have pcd7 and hope to design a basic crosover in the future.
Thanks.
Todd
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nothing wrong with this one...cheap, but good
Dayton Audio DMPC-3.3 3.3uF 250V Polypropylene Capacitor
Dayton Audio DMPC-3.3 3.3uF 250V Polypropylene Capacitor
Hi adason, being open back, are they sensitive to placement? Need certain distance off the back wall? Thank you so much.
Yes, if you keep back open, it helps to place it further from the wall. I think it helps speakers in general, no matter what construction, to keep away from walls.
I use speakers without backwall, because I do not need the box to extend the low end, I only use them 160Hz and up...
I use speakers without backwall, because I do not need the box to extend the low end, I only use them 160Hz and up...
Dear Adson,
those vifa drivers are excellent for money as for the other members. so we can build good budget speakers.
How we can achieve below 160hz. can you post crossover for this also.
Thank you.
those vifa drivers are excellent for money as for the other members. so we can build good budget speakers.
How we can achieve below 160hz. can you post crossover for this also.
Thank you.
Just use ~200µF cap for mtm, and place it on two boxes with woofers with passive crossover or better active. I prefer biamping. Lower woofer efficacy is no issue, many active subs offer variable crossover frequency.
Have fun.
Have fun.
