No need to redesign it. The impedance at 100 Hz is never 2 ohms, the sensitivity at 1m is 85-86 dB and the phase tracking is not bad. The SPL at both crossover frequencies is +6 dB.
Yes with data from model not with real data. Note I own measurements of Focal drivers very closed to the drivers in this thread and sure your modelisation is wrong. I don't write that to bother you, for sure, but I don't have time to loose with this if you don't want to read this.
And I use measurements of the real drivers, not any Focals that are only assumed to be close. By the way, the woofer is not Focal, it is the NHT 1259, and an impedance measurement is here:
Misure Woofer NHT 1259-4
Please check your own simulation, your 2 ohm theory is certainly wrong.
Misure Woofer NHT 1259-4
Please check your own simulation, your 2 ohm theory is certainly wrong.
try 150uf/1R5 zobel on a woofer
I would say thats a tough one try to increase the resistor to somewhere above woofer impedance, it might help
maybe the 4mH could have been bigger
i'm confused now with so many answers as which direction to go now. the crossover that they are hooked up to now, do not sound great. sure, there isn't any distortion at low levels, but i don't want to turn them up loud enough to find out. theres too much "crosstalk" i think you'd call it. definitely needs some work.
so the nominal impedance isn't necessarily what you use to design the crossover with? i found to nominal impedances for the NHT 1259, one says 4 and the other 6.
basically at this point whichever components i can use to get the bass more defined or having punch, and the mids as warm as possible, and no hissing highs thru the tweeters.
if i used an active XO, do i need an amp per driver or would a 2 channel amp work?
so the nominal impedance isn't necessarily what you use to design the crossover with? i found to nominal impedances for the NHT 1259, one says 4 and the other 6.
basically at this point whichever components i can use to get the bass more defined or having punch, and the mids as warm as possible, and no hissing highs thru the tweeters.
if i used an active XO, do i need an amp per driver or would a 2 channel amp work?
why don't you start with your original idea ? not so bad, trust me. The only expensive part is the 130uF cap 35$. The only things I see in your original idea is to reverse the midrange, increase its inductor value to 1mH, add 10ohms in series with the 7.5uF.
And you can keep your 5.5.mH ! I calculate 120$ upgrade with 70$ cap. You can test with 125uF electrolitic cap 3$ total cost 50$.
I think you should not spend too much money with so old drivers.
thanks! so i can use the 5.5mH i already have instead of the 4.78mH? are you saying to wire a 10ohm "resistor" in series with the 7.5uF?sorry to ask such simple questions, so in "series" with the 7.5uF would be -__+ not +__+ like the cap,directly after it but before the inductor? and only the midrange inductor to 1.0mH, and leave the tweeter as .54uF? is .55uF thats 18 or 20 AWG air core inductor be adequate? So its 132.5uF for the highs, would a 150uF or 125uF Non-polarized Electrolytic Capacitor work, if not, what kind of capacitor? same question for the 7.5uF, is using a film and foil cap necessary? and finally, is the zobel circuit to reduce the tweeter by 4dB correct? since resistors can heat up easily, I calculated it for only 15 watts, which is the manufacturers claimed RMS for the tc120's, but they can handle 150w. will a 2.21 ohm 5.5 watt R wired parallel followed by a 10.26 ohm 3.49 watt R wired in series work for the tweeter? thanks again!! am going to sleep now, will check back in the morning...
Usually, the RC is placed there to eliminate impedance peak at the resonant frequency Fs, so that the high-pass network would work more linearly .
yes, and especially if its a better inductor
and try a smaller paralel cap, if you have one
mount it with series resistor 6R8-12R
5watt wirewound is ok, if thats what you have
A lot of questions, i joined a schematic.
Yes for midrange-tweeters foils capacitor is highly recommended ! For test you an use bipolar.
If you can't have :
- 7.5uF use 8.2uF or 6.8uF.
- 0.55mh go to .47mH or 0.56mH
- 130uF go to 125uF instead 150uF, or use 100+33 or 2x68 or 4x33 etc.
Keep the resistor of the inductor below .5ohms, 0.3ohms is fine.
Yes for midrange-tweeters foils capacitor is highly recommended ! For test you an use bipolar.
If you can't have :
- 7.5uF use 8.2uF or 6.8uF.
- 0.55mh go to .47mH or 0.56mH
- 130uF go to 125uF instead 150uF, or use 100+33 or 2x68 or 4x33 etc.
Keep the resistor of the inductor below .5ohms, 0.3ohms is fine.
Attachments
absolutely, and for more than just testing
just remember, you can always try and make a capacitor bigger by adding more in paralel
but you cannot make a big one smaller
bipolars comes in different quality too
roughed foil is used for higher capacity
for quality crossover best use 'smooth foil' caps
some of them might even outperform a film cap
but not always cheap either
edit, migt look at Mundorf E-cap AC (bipolar)
both smooth and rough foils
There is a mismatch between woofer and tweeter but you are matching them with the L-pad. The midrange needs to be 2dB higher than the woofer/tweeter. The tweeter must stay in phase, only the midrange gets it's connections reversed. The golden rule is to match the sensitivities of the woofer and tweeter exactly and get a midrange 2dB higher to make life easier. Have fun.
Mac.
Mac.
am definitely going to build this XO but have been thinking, since it could to cost $150 or more anyway, do you think that it will really improve the sound quality significantly? meanwhile, i could design a simple XO for the nht1259s and get a semi-decent 2-way bookshelf pair for similar price. for instance the SVsound SBS-02 are $150 for a pair on sale and the ascend acoustic CBM-170 are on sale for a couple hundred. have you heard either of these or know of some kickass speakers, prebuilt or kit, around $200 thatd be good for playing analog synths/drum machines thru? also been looking at the diysoundgroup.com MTG-08 speaker kit or the SEOS Delta 12a-kit. my main choice would be a gr-research N2X pair, but they're $500 so probably won't.
its great fun, yes
use cheap inductors etc, and caps like those affordable Mundorf bipolar etc
but it will cost money
and it will still never be good enough for the serious money
if you have higher expectations, then its better to find a proven design you can copy
there are many good ones
and since I was around Curt's speaker projects for another member, here it is again
Im sure you can find a good and cheap project there
http://speakerdesignworks.com/index_page_2.html
but ofcourse there are others
use cheap inductors etc, and caps like those affordable Mundorf bipolar etc
but it will cost money
and it will still never be good enough for the serious money
if you have higher expectations, then its better to find a proven design you can copy
there are many good ones
and since I was around Curt's speaker projects for another member, here it is again
Im sure you can find a good and cheap project there
http://speakerdesignworks.com/index_page_2.html
but ofcourse there are others
The NHTs are very good woofers.
If you are having second and third thoughts about the project why not save for a couple of small plate amps and use the woofers in separate powered boxes??
Then find a reasonable 2-way project to use with them?
Going powered is the best ( and often cheaper ) option when talking about crossover frequencies below 200/120Hz
If you are having second and third thoughts about the project why not save for a couple of small plate amps and use the woofers in separate powered boxes??
Then find a reasonable 2-way project to use with them?
Going powered is the best ( and often cheaper ) option when talking about crossover frequencies below 200/120Hz
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