Test Bench: Tang Band Speaker W8-2314 High-End Coaxial Driver
https://audioxpress.com/article/test-bench-tang-band-speaker-w8-2314-high-end-coaxial-driver
A lot of graphs.
https://audioxpress.com/article/test-bench-tang-band-speaker-w8-2314-high-end-coaxial-driver
A lot of graphs.
Thanks, Maty. The measurements are similar to what I am seeing. There is definitely some ripple in the tweeter but that can be dealt with by setting the peaks at the nominal values and our ears don’t hear the dips.
Hi,
if I may - on my bench today is a new xo (trial version, of course, with parts from the pile, that's the reason for the two inductors in series) for my OB version 2.
I'm planning to use just one woofer and an FR, the xo is a kind-of-Hirsch thingie, my goal was an in-phase configuration. The sim shows fine frequency and impulse response, so I'm curious how it sounds.
X, generally speaking, what voltage should a capacitor have when connected in series between the power amp output and the FR driver? My cap has 50 volts...
if I may - on my bench today is a new xo (trial version, of course, with parts from the pile, that's the reason for the two inductors in series) for my OB version 2.
I'm planning to use just one woofer and an FR, the xo is a kind-of-Hirsch thingie, my goal was an in-phase configuration. The sim shows fine frequency and impulse response, so I'm curious how it sounds.
X, generally speaking, what voltage should a capacitor have when connected in series between the power amp output and the FR driver? My cap has 50 volts...
Here’s what the XO looks like at present.
I aligned the woofer falloff with the electrical low pass to get a 4th order on the woofer, a second order high pass on the tweeter, and positive absolute phase is used on both. The dips in the tweeter response may be caused by the diffraction or reflection interference from the special ridges on the surround. The distance is about right to cause the frequencies observed. But I don’t think the dips are audible if the level is set correctly.
One nice thing is that the impedance curve is really smooth and speaker should be easy to drive. The speaker is a 4ohm design so 4ohm amp should be used. However, if played at normal volumes, many 8ohm class A amps can be used.
I aligned the woofer falloff with the electrical low pass to get a 4th order on the woofer, a second order high pass on the tweeter, and positive absolute phase is used on both. The dips in the tweeter response may be caused by the diffraction or reflection interference from the special ridges on the surround. The distance is about right to cause the frequencies observed. But I don’t think the dips are audible if the level is set correctly.
One nice thing is that the impedance curve is really smooth and speaker should be easy to drive. The speaker is a 4ohm design so 4ohm amp should be used. However, if played at normal volumes, many 8ohm class A amps can be used.
Strange that the woofer and the tweeter dips are at the same spot.
I'll have a look at the measurements of my W6 again.
I'll have a look at the measurements of my W6 again.
50v rating should be fine and even more so in series. When cap goes to ground like a shunt then needs to be able to handle max possible AC voltage. 50v divide by 2.83 is 17.7vrms and that’s about 40w into 8ohms. But in series there is no issue as it really only sees AC signals so there’s no practical limitation - you can use on anything. However, higher voltage rated film caps may sound better. For bipolar electrolytic caps, not sure.
That is one area I’m working on but since I wanted to use the Passive Harsch, the setpoint for the XO is about 4kHz as dictated by woofer falloff and the tweeter dip is naturally there. If you look at the Audioexpress measurement, it’s about the same spot. There’s a dip near 3.8kHz and another near 6kHz and a big one at 11kHz.
One could go with a more conventional LR XO near 2kHz to 3kHz and perhaps avoid having the dip right at the XO, and that is a possible route that I might try next. More components to XO and lose the nice step response. The dip will still be there - but dips are not really that audible.
You can have a listen to this XO here:
Vunce likes metal so I have a couple of tracks to test that genre out. Not all the usual jazz 🙂
The Boston HD5 cabinet (fitted with my MicroFAST speaker drivers and XO) is serving as a stabilization weight since the XPS foam box is so light it might move off the bench or ratttle.
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Sometimes, inverting a driver (first of all tweeter or midrange) can cause the loss of some clarity and openness.
I think tweaking the xo is a better way.
I think tweaking the xo is a better way.
I never invert the woofer, as it will have phase issues if subs are involved, but will sometimes invert the tweet if it helps.
I have it inverted with my series XO and there's plenty clarity and openness still.
X, if I plug in your XO into my W6 measurements, I get a huge impedance spike to 18 Ohms at 1.3kHz.
Otherwise, it almost follows my FR.
I have it inverted with my series XO and there's plenty clarity and openness still.
X, if I plug in your XO into my W6 measurements, I get a huge impedance spike to 18 Ohms at 1.3kHz.
Otherwise, it almost follows my FR.
Perceval, are you using W8-2314? I thought your driver the W6 variant.
As you can see from my predicted impedance curve, there is what I call a gentle rise and not a spike at 1.6kHz. Full width half max (FWHM) of about 2.3kHz (700Hz to 3kHz) so a gentle hill.
As you can see from my predicted impedance curve, there is what I call a gentle rise and not a spike at 1.6kHz. Full width half max (FWHM) of about 2.3kHz (700Hz to 3kHz) so a gentle hill.
It reduced it but then there was a bump (rounded peak) around 2kHz that arises.
Definitely some more tweaking involved and we will settle on something. The first cut is rarely the XO I end up going with.
Yes, the W6... sorry for my wording... not a spike but also a hill like yours.
My series is a small downward curve from 8 Ohms to 4 Ohms.
Yes, but it is under 3 dB, and when listening at seating distance, that 3 dB hump is kinda lost.
I flipped the tweeter polarity, increased the woofer inductor to 0.68mH iron core so more bass now with lower DCR. Midrange has got some nice weight and smoothness to it. Dip at 4kHz is much improved. I reduced the tweeter padding to 3.3ohms for a bit more top end. Very close to final XO I think. I listened to a bunch of test tracks and there is a visceral foot tapping connection now.
Step Response still aligned but polarity peak is opposite:
Here is the final measurement in REW:
The jury is still out on whether or not to use 4.7R or 3.3R on the tweeter padding. I might go back to 4.7R. Let’s give it a day or so to listen.
Have a listen here - a long video but trying get the key intros for each track. Lots of metal here for Vunce’s enjoyment. 🙂
Keep in mind this is a 24L sealed XPS foam box. It will sound much better in a TL as that will bring bass down to 30Hz and reduce distortion in the bass region. Same crossover though as the 10in baffle width is preserved.
Step Response still aligned but polarity peak is opposite:
Here is the final measurement in REW:
The jury is still out on whether or not to use 4.7R or 3.3R on the tweeter padding. I might go back to 4.7R. Let’s give it a day or so to listen.
Have a listen here - a long video but trying get the key intros for each track. Lots of metal here for Vunce’s enjoyment. 🙂
Keep in mind this is a 24L sealed XPS foam box. It will sound much better in a TL as that will bring bass down to 30Hz and reduce distortion in the bass region. Same crossover though as the 10in baffle width is preserved.
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And if you can and have time, maybe try to plug in my series XO and compare to yours. I'd be interested to hear your take on it.
I won't be home for the next 3 months, so I can't try yours anytime soon.
I won't be home for the next 3 months, so I can't try yours anytime soon.
