I think you're right - just found an ebay post with many photos indicating 50v - ACOUSTIC RESEARCH AR-14 ELECTRONIC CROSSOVERS SUPER HIGH QUALITY, 50V COMPONENTS | eBay
AR-14 1976 was obviously electrolytic capacitor as photo, white caps from japan. thew 1970s brochure describes: Half section LCR network on each driver using air-core chokes. Bipolar electrolytic capacitors, and high power non-inductive resistors. Acoustic output of high range driver is controlled by switchable contouring network. So a modern propolylene 50v 16uf and 20uf swap out or is it too simple? Please advise. Do I need to add resistors and go Claritycap or Solen id the appropriate 50v etc is available? I am now at an impasse, but for your goodselves, as to what action to take and purchases to make. Hope the ebay photos located and schematics enable you to decipher. Many thanks Patrick
I personally can't hear any difference in any of the well-made, mid-priced caps, poly or electrolytic. So I would tell you to buy a cap that fits, size and budget, your project and just make sure it's 50V+ and be done. I would do the resistors too, but only because they are cheap. You can measure with a DMM and see if they are more than 10% out of spec.
Changing from electrolytic to any plastic film capacitor will change the sound. And that might not be better.
Some of the change will be due to the change in capacitor esr and can be allowed for during assembly as indicated by AllenB.
If using electrolytic then you must use bi-polar or back to back polar electros.
You can even use back to back bi-polar electro. That reduces the distortion when used as a filter.
Drive from a transformer coupled Valve/Tube amplifier surely can't produce more than 30Vpk. You don't need 400V rated capacitors. 50V, or 63V, or 75V, or 80 V, will do. Even 100V is plenty good enough.
Have a look at motor start capacitors if you really need very high voltage caps.
There is nothing wrong with adding a small value trimmimng capacitor if you can't find exactly the right value. 15uF + 1uF = 16uF and you can change the 1uF to 470nF, or to 1u5F, at a tiny cost to hear what effect that has on the nominal 16uF.
Same for 20uF: 18uF + 1u5F, or 2u2F, or 2u5F (1uF + 1u5F, three is probably the most you want in parallel}.
Some of the change will be due to the change in capacitor esr and can be allowed for during assembly as indicated by AllenB.
If using electrolytic then you must use bi-polar or back to back polar electros.
You can even use back to back bi-polar electro. That reduces the distortion when used as a filter.
Drive from a transformer coupled Valve/Tube amplifier surely can't produce more than 30Vpk. You don't need 400V rated capacitors. 50V, or 63V, or 75V, or 80 V, will do. Even 100V is plenty good enough.
Have a look at motor start capacitors if you really need very high voltage caps.
There is nothing wrong with adding a small value trimmimng capacitor if you can't find exactly the right value. 15uF + 1uF = 16uF and you can change the 1uF to 470nF, or to 1u5F, at a tiny cost to hear what effect that has on the nominal 16uF.
Same for 20uF: 18uF + 1u5F, or 2u2F, or 2u5F (1uF + 1u5F, three is probably the most you want in parallel}.
I have a different question here.
I am building HT set up , with an Onkyo 5.1 receiver. 5 Full rangers with Dayton RS100-8 driver and .1 sub with Dayton SD215A-88 DVC sub driver.
Now Onkyo receiver has the option of setting Xover frequency and i intend to keep it at 100Hz for the full rangers.
Will this set-up work for not so critical listening of the movies. I have the option of fitting of a 24bD/Oct active sub x-over with all controls for the sub, but it will only complicate set-up and cost me too many $$$
Here is the proposed set up which I had shared on another thread, but posting here for convenience...
https://3dwarehouse.sketchup.com/model.html?id=e43291be-35ae-4ad6-8dd1-b97357b34bab
Of course all the full range speakers will be turned towards ear of listener (I am not all that good with Sketchup) and will be kept at ear level approximately.
reg
Prasi
P.S. I did trouble some members here (especially Wintermute) for my stereo floor standers, but thankful to all those... I am enjoying the musical stereo experience for two.5 years straight albeit with different amps / preamps now and then
..
I am building HT set up , with an Onkyo 5.1 receiver. 5 Full rangers with Dayton RS100-8 driver and .1 sub with Dayton SD215A-88 DVC sub driver.
Now Onkyo receiver has the option of setting Xover frequency and i intend to keep it at 100Hz for the full rangers.
Will this set-up work for not so critical listening of the movies. I have the option of fitting of a 24bD/Oct active sub x-over with all controls for the sub, but it will only complicate set-up and cost me too many $$$
Here is the proposed set up which I had shared on another thread, but posting here for convenience...
https://3dwarehouse.sketchup.com/model.html?id=e43291be-35ae-4ad6-8dd1-b97357b34bab
Of course all the full range speakers will be turned towards ear of listener (I am not all that good with Sketchup) and will be kept at ear level approximately.
reg
Prasi
P.S. I did trouble some members here (especially Wintermute) for my stereo floor standers, but thankful to all those... I am enjoying the musical stereo experience for two.5 years straight albeit with different amps / preamps now and then
..
Last edited:
You have a question about using a crossover at 100Hz. I assume this means the mains will work above and the sub, below. In my opinion the benefit of crossing the mains here depends on power handling. Frequencies below 100Hz (and to some degree above) are more or less under the control of your room, ie room modes are the thing to look at here.
Using the mains below 100Hz (in addition to the sub) could improve (if done right) the room mode distribution. Another way of approaching this is to cross at 100Hz and use more than one sub.
Using the mains below 100Hz (in addition to the sub) could improve (if done right) the room mode distribution. Another way of approaching this is to cross at 100Hz and use more than one sub.
Thank you Allen.
Unfortunately the RS100-8 's power handling below 100Hz is limited in a ported box (doesnt take much to hit x-max).
I will think about adding one more sub, once the set is ready and auditioned. which location would be ideal for the second sub? behind the listener?
Yes, I will keep the center channel vertical and at same level as other full range speakers.
regards
Prasi
Unfortunately the RS100-8 's power handling below 100Hz is limited in a ported box (doesnt take much to hit x-max).
I will think about adding one more sub, once the set is ready and auditioned. which location would be ideal for the second sub? behind the listener?
Yes, I will keep the center channel vertical and at same level as other full range speakers.
regards
Prasi
While it isn't easy to answer that question without measurements, generally a second sub shouldn't be too symmetrically located with respect to the other one. You might try along a side wall and maybe off the floor. Try swapping the polarity. There is a whole thread on the subject when you get to it.
Mr. Allen B. I really thank you all your replies: Here in Argentina it is absolutely impossible to get 6.5 inches woofers I am planning to make a "MTM", I respectfully ask you for an advice. As It is only available 6 inches woofers would it be possible to use 6 inches woofers in such design? I know that 6.5 inches woofers are used in benefit of reaching better low-frecuency perfomance, but here I can not get those 6.5 woofers-(midwoofers). Please advise me if this would be possible using 6 inches woofers for such design and get a decent result. Thank you in advance, Master of all of us: Kindly Black Monk
Dear Mr. AllenB: is a gift of God that you are in diyaudio, your kindness and your wisdom. You´re always ready to answer our doubts, Thanks may God Give you all you deserve and more. Your article about crossovers was a Bless for all of us, only you can produce a master piece of teaching so extense and easy to read and learning. Let me tell yo that you are one of a kind, the boxes of the "MTM" with 6 inches "mids" are almost ready.
Thank you Master of the Masters; Black Monk...
Thank you Master of the Masters; Black Monk...
Dear AllenB hello. Thank you so much for this thread. You helped me to make a 2nd order cross for my handmade floorstanding speakers (I think so)
I have the units below per enclosure:
1pc. Monacor dome tweeter DT-280 8ohm
2pcs.Peerless SDS-164-THP 6.5 inch woofer coated paper 8ohm
What diameter do you recommend for woofer air coil?
I have the units below per enclosure:
1pc. Monacor dome tweeter DT-280 8ohm
2pcs.Peerless SDS-164-THP 6.5 inch woofer coated paper 8ohm
What diameter do you recommend for woofer air coil?
Big !
If you want/need least resistance, then a coil with an outside diameter approximately 4 times the coil thickness is near optimum.
The bore/bobbin should be approximately 2 times the coil thickness.
Say you have a 40mm bobbin with the winding cheeks set 20mm apart.
Wind on turn to fill the bobbin up to 80mm diameter.
The coil shape is ~ 20mm by 20mm and the hole in the middle is 40mm. That shape minimises the resistance for that amount of inductance.
But this square shape of coil with a big hole may have higher parasitic capacitance.
I have not found data that confirms shape to parasitics.
Thanks for you answer. Do we prefer 12-16AWG wire for woofer's coil?
Now I have coils with 20AWG = 0.8mm wire at 0.82mH.