UB class of crossovers

Ralf.Hoellmann
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Re: UB class of crossovers

Post by Ralf.Hoellmann » 31 Mar 2020 08:34

Hi Uli,
Hi Murray,

yes, the clarifications Uli has added are correct. Even though in my 1st set-up the close-up mic linearizationsounded best, the 30-40cm sounds even better. In particular in case of - even smal scale - driver deficiencies, these may become overly corrected.

In any case, I strongly encourage you to measure at various ditances and listen to the final result. Your speaker/ set-up may just produce even better results at different distances. Clearly, the distance has got a strong sonic influence on the overall result!

Regards, Ralf
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Labdoc
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Re: UB class of crossovers

Post by Labdoc » 31 Mar 2020 12:36

Ralf,
Please describe the speaker characteristics, such as closed box, ported or not, diameter, conventional cones or horns
Do you find that the UB crossover is unique in this respect? In other words, did you try linearizing with the former default NT4 crossover using nearfield measurements and find the same observations?
Murray
Acourate/AConvolver on Win 11x64 > Thunderbolt > RME UFXplus (as DAC/preamp) > Balanced cable > Wyred4Sound SX1000 Icepower mono amps > ATC SCM50PSLT and stereo JL Audio F113 subs
Ralf.Hoellmann
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Re: UB class of crossovers

Post by Ralf.Hoellmann » 31 Mar 2020 14:21

Hi Murray,

it is the black gloss finish speaker on the right side: https://6moons.com/audioreviews2/suesskind/2.html.

In my version, the bass cabinet is closed.

My early versions were using the NT4 crossovers. I personally find the UB-class ones sonically superior. They sound more open and "acourate".

Regards, Ralf
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Labdoc
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Re: UB class of crossovers

Post by Labdoc » 05 Apr 2020 19:53

Ralf, thank you for the information.

Uli and others -
Uli suggested to compare the new crossover variants using RMSlog plots. While differences are obvious, how does one interpret these plots? Is there a golden target? Subjective opinions have already been expressed in the forum. Are there objective targets to look for?
Attached:
NT(3) VS UBCOS(1) - read as NT 3rd order vs UBcos 1st order etc
NT(3) VS UBPOL11(1)
NT(3) VS UBPOL11(3)
1-NT3-UBCos1.jpg
1-NT3-UBCos1.jpg (52.91 KiB) Viewed 5600 times
2-NT3-UBpol11(1).jpg
2-NT3-UBpol11(1).jpg (51.79 KiB) Viewed 5600 times
3-NT3-UBpol11(3).jpg
3-NT3-UBpol11(3).jpg (51.25 KiB) Viewed 5600 times
Acourate/AConvolver on Win 11x64 > Thunderbolt > RME UFXplus (as DAC/preamp) > Balanced cable > Wyred4Sound SX1000 Icepower mono amps > ATC SCM50PSLT and stereo JL Audio F113 subs
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UliBru
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Re: UB class of crossovers

Post by UliBru » 06 Apr 2020 10:01

Murray,

if you like to compare the UB crossovers with NT you should use the same filter order. The XOs should have about the same width of the transition area. Clearly XOs with a wider area will show less ringing.
Now if you compare filters of same order the RMSLog pictures show the attenuation of the pulse at the outer sides. The center will nearly look identical. The more attenuation you get the less ringing you have.
So e.g. create a NT crossover 1st order and a jPol11 XO 1st order and compare them by RMSLog. You will notice a shorter ringing with the jPol filter (= more attenuation in RMSLog display)
Stay well tuned
Uli

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Acourate system: JRiver/Roon -> AcourateConvolver -> miniDSP U-DIO8 -> TacT M/S2150 amps -> DIY horn speakers
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Labdoc
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Re: UB class of crossovers

Post by Labdoc » 06 Apr 2020 19:41

Uli, Thanks
In older versions of Acourate, the default setting was NT4. More recently, Acourate opens to UBcos first order. Of course, NT4 and UBcos(1) present differently-shaped curves in RMSlog, Step response and in Amplitude. Mitch Barnett's book and examples used NT4.

For unsophisticated use, is there a recommended UB crossover? 4th order UBcos or UB polynomials would seem to be the analogous crossover to NT4.

Murray
Acourate/AConvolver on Win 11x64 > Thunderbolt > RME UFXplus (as DAC/preamp) > Balanced cable > Wyred4Sound SX1000 Icepower mono amps > ATC SCM50PSLT and stereo JL Audio F113 subs
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UliBru
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Re: UB class of crossovers

Post by UliBru » 07 Apr 2020 10:59

Murray,

IIRC the default setting always has been NT2. Also Mitch is using NT2 filters in his book.
So I have used NT2 for quite a long time. Today I prefer using UB XOs, mainly 1st order, sometimes 2nd order. But I also use Bessel filters from time to time.
When you compare NT and UB simply use the same filter order.
Stay well tuned
Uli

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Acourate system: JRiver/Roon -> AcourateConvolver -> miniDSP U-DIO8 -> TacT M/S2150 amps -> DIY horn speakers
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Labdoc
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Re: UB class of crossovers

Post by Labdoc » 07 Apr 2020 14:12

Uli, your memory about Mitch's book is better than mine! Yes, NT 2nd order is what he used.
Thanks for sharing which crossovers you use. Until this thread, I had not thought much about the crossover type and order.
Murray
Acourate/AConvolver on Win 11x64 > Thunderbolt > RME UFXplus (as DAC/preamp) > Balanced cable > Wyred4Sound SX1000 Icepower mono amps > ATC SCM50PSLT and stereo JL Audio F113 subs
PhilActiveAudio
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Re: UB class of crossovers

Post by PhilActiveAudio » 23 Feb 2021 19:08

Hi to all,

This is an old subject, but I share my measurement practices.

Using a different software (I am just starting with Acourate) I measured my 3 drivers at 40cm, 60cm, 80cm and 100cm. Measures where done at the height of each driver center, so 3 different heights.

First, the shape of the measures of each driver are very different, especially for mid and tweeter. The best shapes were the measures done at 80 and 100cm. Corrections done using 40 and 60cm measures (same parameters, XO...) were not good. Corrections with 80 and 100cm were good.

I did an additional measurement of the 3 drivers at one unique height: 100cm (in the middle of the 3 drivers) and 100cm distance. Using the same parameters, correction is pretty good.

I now need to check with Acourate.
exaSound e68 DAC ==> class D / Accuphase / class D ==> Jensen Supravox / Arai Radian / Fostex
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UliBru
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Re: UB class of crossovers

Post by UliBru » 24 Feb 2021 09:23

Please tell us about your findings :)
Stay well tuned
Uli

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Acourate system: JRiver/Roon -> AcourateConvolver -> miniDSP U-DIO8 -> TacT M/S2150 amps -> DIY horn speakers
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