I think you would be surprised how much is possible with sound character differentiation with a little video like this, at least for someone that has heard a great many of these (in a vast array of varying recording quality). What an experienced listener should always do however is accept limitations with freq. linearity and balance (particularly with lower freq.s.).
Not lacking mid treble and upper freq.s, rather lacking lower-level signal detail in this freq. range. Air, delicacy, upper freq. sound-stage detail, etc.. In fact based on the forward character I’d say that the averaged response is a little “hot” currently - just a bit higher in level than it should be. ”Flat” in-room isn’t always the best design unless the result is Omni. Narrow dispersion at higher freq.s tends to generate a perceptually “brighter” sounding result all-else equal (and this is counterintuitive).But it definitely don't lacking mid-treble and upper freq…
Listening to it is really fine, of course there is much room for improvement, and I will try some of them (as I also will try the A12P in this config too).
One thing makes me "proud", or at least I'm glad it's audible: your comment regarding tonality and dynamics in the "phone range". That's why I adore OB.
Yeah, as-is it’s still a result to be proud of.
I can't comment it, because I don't have this experience with crippled recordings, but it's great if you are able to differenciate!
Yes, maybe "hot", but hot means for me bad, because I don't like overemphasized things, so I think it's rather very lively, but it's surely a matter of personal taste too. However, I will do some level adjustment as I wrote somewhere, in this phase I just wanted to know if it is okay for some degrees.
Many thanks
Hi again,
here I have the provisionally final
2-way version with in-phase xo.
@Scott G , you were right, the previous version sounded really "hot" - not as a first impression, but during long listening sessions. And the measurement has also confirmed this. I've now played with the attenuation of the FR and the result is a lively sound that however isn't tiring or forced. Interesting: I've heard the speaker with both the M2x and Xrk's Warp - and they both require different FR level adjustments. I will still play with the wings and will probably leave it out in the FR area. Regarding the - expected - question about the middle baffle: it is well suited for sound tuning, depending on the distance between the two drivers the sound is more airy or more coherent - I like it more airy.
First measurements show a flat frequency response with some tilt from the left to the right.
here I have the provisionally final
2-way version with in-phase xo.@Scott G , you were right, the previous version sounded really "hot" - not as a first impression, but during long listening sessions. And the measurement has also confirmed this. I've now played with the attenuation of the FR and the result is a lively sound that however isn't tiring or forced. Interesting: I've heard the speaker with both the M2x and Xrk's Warp - and they both require different FR level adjustments. I will still play with the wings and will probably leave it out in the FR area. Regarding the - expected - question about the middle baffle: it is well suited for sound tuning, depending on the distance between the two drivers the sound is more airy or more coherent - I like it more airy.
First measurements show a flat frequency response with some tilt from the left to the right.
Hi,
I have been following your thread. And this my 2 cents. I have a 15" Audio Nirvana with 2 x 15" bianco and a Aurum Cantus ribbon tweeter on mine.
OB works best with DSP or at least some sort of active bass boosting circuit. Open baffles roll off after about 100+ Hz, so some form of boosting at the 30 to 50 Hz region will help to equalize it. Bianco is capable of crazy loud bass matching many box speaker if boosted since they are typically less than 8". And the bass is quite clean.
I also have the SB20 FR... I find it a strange animal. When I first played it, wasn't impressed with the sound. Put it away for a month suddenly a major improvement. Maybe it needs time to adjust moisture on the cone.
There are Some drivers you should try, I haven't tried it on my OB yet. But I like the overall sound signature. Faitalpro 3Fe22 or the 4Fe42 I think. Not so much the 4Fe32 unless you have EQ to tame the 8kHz peak. All 91 db sensitivity and plays really loud if there is no bass. And some of those GRS planar speakers found in Part Express. They go very low for ribbons, so worth giving it a shot.
Finally, first orders don't really behave like first orders in high pass. When the frequency approaches Fs, it gets a boost of some kind as the impedance climbs. Putting a resistor that is 2 or 3X the original in parallel with driver helps.
Cheers,
Oon
I have been following your thread. And this my 2 cents. I have a 15" Audio Nirvana with 2 x 15" bianco and a Aurum Cantus ribbon tweeter on mine.
OB works best with DSP or at least some sort of active bass boosting circuit. Open baffles roll off after about 100+ Hz, so some form of boosting at the 30 to 50 Hz region will help to equalize it. Bianco is capable of crazy loud bass matching many box speaker if boosted since they are typically less than 8". And the bass is quite clean.
I also have the SB20 FR... I find it a strange animal. When I first played it, wasn't impressed with the sound. Put it away for a month suddenly a major improvement. Maybe it needs time to adjust moisture on the cone.
There are Some drivers you should try, I haven't tried it on my OB yet. But I like the overall sound signature. Faitalpro 3Fe22 or the 4Fe42 I think. Not so much the 4Fe32 unless you have EQ to tame the 8kHz peak. All 91 db sensitivity and plays really loud if there is no bass. And some of those GRS planar speakers found in Part Express. They go very low for ribbons, so worth giving it a shot.
Finally, first orders don't really behave like first orders in high pass. When the frequency approaches Fs, it gets a boost of some kind as the impedance climbs. Putting a resistor that is 2 or 3X the original in parallel with driver helps.
Cheers,
Oon
My (personal) “next stop” would be a 2nd order electrical high-pass for a Beston dipole planar tweeter around 4 kHz along with enough physical set-back and inverted polarity while trying out different angles (horizontal “toe-out”) to achieve a good low-pass result for the full range driver for the listener’s axis that sums well with the tweeter’s high-pass.
Hi Oon,
thanks for your reply. One thing I really don't want to do is to use dsp - I just have quality concerns and no experience, while I'm about to start understanding how an xo on real life works and why don't
Sure, there are many drivers to try and I will try some of them, but I go step by step, trying to achieve the best possible behavior of a driver (that cheap).
thanks for your reply. One thing I really don't want to do is to use dsp - I just have quality concerns and no experience, while I'm about to start understanding how an xo on real life works and why don't
Sure, there are many drivers to try and I will try some of them, but I go step by step, trying to achieve the best possible behavior of a driver (that cheap).
My understanding is drivers like eminence alpha 15A with high QTS doesn't need a DSP or EQ to boost low ends, it can easily achieve 40hzHi Oon,
thanks for your reply. One thing I really don't want to do is to use dsp - I just have quality concerns and no experience, while I'm about to start understanding how an xo on real life works and why don't
Sure, there are many drivers to try and I will try some of them, but I go step by step, trying to achieve the best possible behavior of a driver (that cheap).
It really depends on your crossover point, width of panel and of course most of all, your taste. If you are happy at 100+ Hz slowly rolling of at 6 db per octave, then, okay... it is really about the backwave shorting the front rather than actual driver. A high qts driver will probably give it more boost until the the Fs of the speaker. But if you are the type who wants flat till 30 Hz, then u would need a boost.
This is an interesting article by troels. Best bass from any speaker he has built. And he has built a lot ...
http://www.troelsgravesen.dk/OBL-15.htm
Oon
This is an interesting article by troels. Best bass from any speaker he has built. And he has built a lot ...
http://www.troelsgravesen.dk/OBL-15.htm
Oon
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It depends on your measuring distance. The nearer you are the speaker, more nearfield, the more the measurements take the output from the front of driver and is less influenced by the backwave. Also affected by distance to backwall. The further you go away the the backwave becomes more prominent and cancelation increases. The good news is your bass doesn't go to your neighbor's house. So you can play really loud. However room mode comes into play and response goes all over the place. I don't have a good answer how to measure bass response of a open baffle. I think nobody knows for sure yet.
Like I mentioned if YMMV, if you are happy with it, just go with it. I have 2 bianco a side and I put in about 15db of boost. They are driven by a 100W class D. I wanted to be flat as much as possible to 30Hz
Like I mentioned if YMMV, if you are happy with it, just go with it. I have 2 bianco a side and I put in about 15db of boost. They are driven by a 100W class D. I wanted to be flat as much as possible to 30Hz
Did you measure in stereo or one channel only. I find stereo tends to be more bassy. This due to constructive interference.
There is also the element of expectation. For me this was going to be my main and ultimate speaker not another hifi project. So I was looking for it to do bass like Wilson Audio or one of those big floorstanders. That means frequency response of down to 30 Hz or something to that effect. I could see that yours has a response down to about 50Hz. So that was high expectations. Anyway the Bianco has 1cm worth of X-max.. why not use it. Since I have 2 perside that is a 6db increase in sensitivity. Actually one should be enough, but I was greedy. And the Bianco is relatively cheap.
Oon
There is also the element of expectation. For me this was going to be my main and ultimate speaker not another hifi project. So I was looking for it to do bass like Wilson Audio or one of those big floorstanders. That means frequency response of down to 30 Hz or something to that effect. I could see that yours has a response down to about 50Hz. So that was high expectations. Anyway the Bianco has 1cm worth of X-max.. why not use it. Since I have 2 perside that is a 6db increase in sensitivity. Actually one should be enough, but I was greedy. And the Bianco is relatively cheap.
Oon
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It was one channel only.
Yes, sometimes it should be my ultimate speaker too (until I can afford a Wilson), but I also want to learn, that's why I started with cheapo driver. But I will definitely increase the quality of the drivers. So this is a hifi project as well, that's the fun part.
Yes, sometimes it should be my ultimate speaker too (until I can afford a Wilson
), but I also want to learn, that's why I started with cheapo driver. But I will definitely increase the quality of the drivers. So this is a hifi project as well, that's the fun part.
To be honest. Wilson Audio sounds Slam bass etc at hifi shows etc. And I have heard them many times. However they are not anywhere near my top list. They only sound good played really loud.
Best system I heard recently is a NAD anniversary amp and a PSB audio speaker with DIRAC live. It was incredibly natural. They gave a demo with DIRAC live turned off. Difference is night and day So my conclusion was DIRAC live and room calibration is really essential for hifi music.
So my next purchase is a Minidsp flex 8 with DIRAC live. I am using an older unit of the flex 8. If you are doing 2 way you can consider minidsp HD. Only US$200+ only.
Best system I heard recently is a NAD anniversary amp and a PSB audio speaker with DIRAC live. It was incredibly natural. They gave a demo with DIRAC live turned off. Difference is night and day So my conclusion was DIRAC live and room calibration is really essential for hifi music.
So my next purchase is a Minidsp flex 8 with DIRAC live. I am using an older unit of the flex 8. If you are doing 2 way you can consider minidsp HD. Only US$200+ only.