Sound good!
Hi guys, I may have a pair of the earliest speakers with Mark's ERDXT design.
I used my Zaph L18 boxes, just dropped in new parts in December 09. The magic lies in waveguide and 2nd order xo low enough in freq, I think. I really love the sound and they work wonderfully for my needs - a living room-HT-stereo-allround-background etc. For serious 2ch audiophile listening I would want something special (dipole, WMTMW...)
Fiddling with cabinet volume and stuffing has very minor effects and one's room and placement have even more effect. So fiddling with port tuning and stuffing is anyway recommended and is always reversible, so don't worry about that, just try it and make it sound the best for your ears.
Mark gave me good support by email, but sorry I don't have good enough measuring system to post any graphs. In general I think this must be one of the best reasonably-priced 2way designs. Im quite sure that Jon's new Modula will be very close.
Go for it!
Juha
Hi guys, I may have a pair of the earliest speakers with Mark's ERDXT design.
I used my Zaph L18 boxes, just dropped in new parts in December 09. The magic lies in waveguide and 2nd order xo low enough in freq, I think. I really love the sound and they work wonderfully for my needs - a living room-HT-stereo-allround-background etc. For serious 2ch audiophile listening I would want something special (dipole, WMTMW...)
Fiddling with cabinet volume and stuffing has very minor effects and one's room and placement have even more effect. So fiddling with port tuning and stuffing is anyway recommended and is always reversible, so don't worry about that, just try it and make it sound the best for your ears.
Mark gave me good support by email, but sorry I don't have good enough measuring system to post any graphs. In general I think this must be one of the best reasonably-priced 2way designs. Im quite sure that Jon's new Modula will be very close.
Go for it!
Juha
Attachments
Oh, you thought I meant last weekend...
Probably the best way to explain the port length it to look at Zaph's PDF.
Zaph's inner tube length is 2.25 (see the pdf) and mine is 2.75".
It's a precision 2" flared port. The total length is 7.75"-which is what you get when you trim the center piece to 2.75".
Hopefully that was clear. If you're using a straight tube you're just going to have to experiment a bit.
Probably the best way to explain the port length it to look at Zaph's PDF.
Zaph's inner tube length is 2.25 (see the pdf) and mine is 2.75".
It's a precision 2" flared port. The total length is 7.75"-which is what you get when you trim the center piece to 2.75".
Hopefully that was clear. If you're using a straight tube you're just going to have to experiment a bit.
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Hi
I'm interested in the ER18DXT, but the problem is that several capacitor and inductor values are not sold on European sites.
(for example 2.5mh, 0.6mh, 5.1µf...)
For capacitor we can manage by adding values but for inductors it's
Would it be possible to get a version of the filter with normalized values?
(for example with 2.2mh OR 2.7 but not 2.5)
for 0.6mh I can take a 5.6 instead I guess.
I'm interested in the ER18DXT, but the problem is that several capacitor and inductor values are not sold on European sites.
(for example 2.5mh, 0.6mh, 5.1µf...)
For capacitor we can manage by adding values but for inductors it's
Would it be possible to get a version of the filter with normalized values?
(for example with 2.2mh OR 2.7 but not 2.5)
for 0.6mh I can take a 5.6 instead I guess.
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Unwind coils and measure value with a simple multimeter from i.e. Selectronic:
SELECTRONIC ::: L'univers électronique :::
SELECTRONIC ::: L'univers électronique :::
European xo-parts are mainly from German sources (Intertechnic), here is a list of my compenents for ER18DXT. Generally within 10% is quite good, hardly hearable. One can also connect components in series or parallel to get right values. Unwinding a coil is easy but measuring?
I can't measure my speakers (well) but at least I like the sound!
L3 aircoil CU 1.00 mm 0.56 mH; (1,00mm should be 18AWG and
1,4mm 15G)
L2,L4 aircoil CU 1.00 mm 0.22 mH;
L1 aircoil CU 1.40 mm 2.70 mH;
C2 Audyn Cap 5.60 uF 400 V 5%;
C4 Audyn Cap 15.00uF 400 V 5%;
C3 Audyn Cap 4.70 uF 400 V 5%;
C5 Audyn Cap 2.70 uF 400 V 5%;
R2 MOX 10W 2.20 ohm;
R1 MOX 10W 2.70 ohm;
R5 MOX 10W 33.0+27.0 ohm (in series);
R3,R4, ceramic 10W 3.30 ohm;
Price for speakers were 268 EUR including taxes and shipping from
europe-audio.com Netherlands to Finland. XO parts were 130 EUR (1 EUR is
roughly 1,4 USD) from a Finnish vendor
I can't measure my speakers (well) but at least I like the sound!
L3 aircoil CU 1.00 mm 0.56 mH; (1,00mm should be 18AWG and
1,4mm 15G)
L2,L4 aircoil CU 1.00 mm 0.22 mH;
L1 aircoil CU 1.40 mm 2.70 mH;
C2 Audyn Cap 5.60 uF 400 V 5%;
C4 Audyn Cap 15.00uF 400 V 5%;
C3 Audyn Cap 4.70 uF 400 V 5%;
C5 Audyn Cap 2.70 uF 400 V 5%;
R2 MOX 10W 2.20 ohm;
R1 MOX 10W 2.70 ohm;
R5 MOX 10W 33.0+27.0 ohm (in series);
R3,R4, ceramic 10W 3.30 ohm;
Price for speakers were 268 EUR including taxes and shipping from
europe-audio.com Netherlands to Finland. XO parts were 130 EUR (1 EUR is
roughly 1,4 USD) from a Finnish vendor
Hi,
well, at least Mark didn't turn me down! My box has different volume and baffle dimensions anyway, but I think I'm close enough.
I shouldn't really call my speakers Mark's ER18DXT, but I'm sure that I benefit from the major principles of design well enough. If I had decent facilities to measure my system I could tune component values to maximize the performance... but I'm not at that level of audiophilia! (Basically this is a philosophical statement - I will settle with this accuracy. But I'm sure there will be the day I start a new project!)
But hey, maybe Mark himself has something to say about values?
Juha
well, at least Mark didn't turn me down! My box has different volume and baffle dimensions anyway, but I think I'm close enough.
I shouldn't really call my speakers Mark's ER18DXT, but I'm sure that I benefit from the major principles of design well enough. If I had decent facilities to measure my system I could tune component values to maximize the performance... but I'm not at that level of audiophilia! (Basically this is a philosophical statement - I will settle with this accuracy. But I'm sure there will be the day I start a new project!)
But hey, maybe Mark himself has something to say about values?
Juha
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Crazyhub: Do we need the sign "Mh" on the multimeter? You need the sign Lx and a range of shelfs i.e. 20 / 2 / 200m / 20m / 2m I wonder if the low prices are precise enough to see a difference between 2.5 and 2.7 obviously yes; for example the selectronic SEL-2327 makes the job finely; i.e. I measured today a couple of 0.241 and 0.239 mH coils for my cosette (agno)
It's always hard to know exactly how a modified version will come out. If it sounds good, well, then, I'll take some credit for it. If it doesn't, well, that's what you get for not following my directions exactly...
2 months later...
the filter components:
Clarity Cap PX everywhere, except for C2 for which I used Russian NOS paper in oil.
Coils similar to Mark K's advised models except for 2.5mh of ER18 which is an Erse SUPER Q core coil.
It's just been finished and still has to run in but the result is already interesting. The result sounds very 3d-shaped and alive. Tweeter is still a bit "hard", I'll see if I increase or not R1 value in a few weeks.
And... Tx Mark K if you pass by.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
the filter components:
Clarity Cap PX everywhere, except for C2 for which I used Russian NOS paper in oil.
Coils similar to Mark K's advised models except for 2.5mh of ER18 which is an Erse SUPER Q core coil.
It's just been finished and still has to run in but the result is already interesting. The result sounds very 3d-shaped and alive. Tweeter is still a bit "hard", I'll see if I increase or not R1 value in a few weeks.
And... Tx Mark K if you pass by.
2 months later...
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
the filter components:
Clarity Cap PX everywhere, except for C2 for which I used Russian NOS paper in oil.
Coils similar to Mark K's advised models except for 2.5mh of ER18 which is an Erse SUPER Q core coil.
It's just been finished and still has to run in but the result is already interesting. The result sounds very 3d-shaped and alive. Tweeter is still a bit "hard", I'll see if I increase or not R1 value in a few weeks.
And... Tx Mark K if you pass by.
Thanks! They look slick.
Depending on how close you are when you listen, you may or may not need to adjust the tweeter padding a bit.
Congrats, Sypher! Nice work, I hope you like the sound. I'm consistently happy with my versions. They are in a big room and I back up them with a sub 20-80Hz, which isn't really necessary but I just happen to have that sub connected anyway.
I think the real advantage of DXT is that you don't have to do those tricks and modifications to make WG fit to the tweeter and baffle.
Juha
I think the real advantage of DXT is that you don't have to do those tricks and modifications to make WG fit to the tweeter and baffle.
Juha