THAT makes me understand why! Thank you. Makes perfect sense now.
Is the output on the ASP a lot lower than an equivalent DSP?
I've built my ASP from the kit, and am enjoying the quality of the sound very much. But it seems like the output levels are quite low... or at least lower than my previous MiniDSP-HD based setup in the same system.
Does anyone know a good way to measure this more objectively? I hooked the device up to a computer and a DAC and its outputs back into the computer, and ran some full scale white noise... and I used REW to try and measure it, but the levels seemed to be very low (like -50dB). I'm no expert with REW, though, and probably don't know what I'm doing.
So there's my first question: Can one reliably measure the output behaviors and level with REW? I'd love to get a curve to make sure that the components I got are working as hoped.
The components I received in my kit didn't match those that Nelson wrote about in his doc... which is kinda why I'm even asking. My measured values on the circuitboard didn't match his ranges either, though they may not have been "wildly off" (I don't know what "wild" is here; for example is 1.5V "wildly" over 1.0V? My assumption is that things are "right" on the board, but I'd like to confirm it.)
In the original doc there are two graphs of the ASP measured:
The first one indicates that the levels approach about zero at least near the bass bump. The second seems to indicate it's down about 20dB (maybe that's just from overlaying the graphs?).
So I'm not sure what to expect here.
But in-use, I'm having to REALLY crank the volume up on my system, and using any EQ on that side seems to introduce some distortion :-( This makes me think that the levels coming INTO the ASP are quite hot, but they're coming out pretty low. And yep, I know about the -12dB on the full-range side; but that was the same with the DSP.
Any thoughts? Thank you for reading this long post.
I've built my ASP from the kit, and am enjoying the quality of the sound very much. But it seems like the output levels are quite low... or at least lower than my previous MiniDSP-HD based setup in the same system.
Does anyone know a good way to measure this more objectively? I hooked the device up to a computer and a DAC and its outputs back into the computer, and ran some full scale white noise... and I used REW to try and measure it, but the levels seemed to be very low (like -50dB). I'm no expert with REW, though, and probably don't know what I'm doing.
So there's my first question: Can one reliably measure the output behaviors and level with REW? I'd love to get a curve to make sure that the components I got are working as hoped.
The components I received in my kit didn't match those that Nelson wrote about in his doc... which is kinda why I'm even asking. My measured values on the circuitboard didn't match his ranges either, though they may not have been "wildly off" (I don't know what "wild" is here; for example is 1.5V "wildly" over 1.0V? My assumption is that things are "right" on the board, but I'd like to confirm it.)
In the original doc there are two graphs of the ASP measured:
The first one indicates that the levels approach about zero at least near the bass bump. The second seems to indicate it's down about 20dB (maybe that's just from overlaying the graphs?).
So I'm not sure what to expect here.
But in-use, I'm having to REALLY crank the volume up on my system, and using any EQ on that side seems to introduce some distortion :-( This makes me think that the levels coming INTO the ASP are quite hot, but they're coming out pretty low. And yep, I know about the -12dB on the full-range side; but that was the same with the DSP.
Any thoughts? Thank you for reading this long post.
The LX-mini analog crossover does not provide any gain, so the output can only be lower than its input. If your DSP was set-up with gain, then its output would be greater than that of the analog crossover.
The levels on that DSP/ASP graph are separated just for clarity purposes. It's not representative of anything absolute.
For the ASP, just make sure the input tweakers are at maximum. That's all the level you can get.
Dave.
For the ASP, just make sure the input tweakers are at maximum. That's all the level you can get.
Dave.
I certainly didn't do that; standard full scale and -12dB as per Linkwitz. Thanks though.
They are. Thanks
I'm not looking for a level boost; I'm trying to calibrate my expectations about how the ASP should work.
If someone were to say either "nope, that's not right; it should be about the same" ... or ... "yep, that's about right, the ASP is NNdB quieter than a comparable DSP solution". 🙂
In any case, thanks for the quick help.
My ASP has the same level in my system, as when it's not in my system, this is when the input pots on the ASP are fully CW. No change. I've never had nor used DSP, so I can't comment on my systems level with DSP.
Then again, my ASP filters were built for SLOB speakers.
Your curves look similar up to 9K, then the DSP has greater level variations. Since the ASP has unity gain buffers, the level should be your systems level.
Then again, my ASP filters were built for SLOB speakers.
Your curves look similar up to 9K, then the DSP has greater level variations. Since the ASP has unity gain buffers, the level should be your systems level.
Well, you mentioned components and voltages maybe not being correct for your ASP. So, you could have an improperly operating ASP, I suppose.
Also, depending upon what DSP unit you had previously, it might have been yielding +6db due to balanced interface output configuration. In that case you would have lost 6db. That's easily audible.
Those are just my guesses at the moment. 🙂
Dave.
Thanks everyone; my DSP was MiniDSP-HD, as I wrote.
Does anyone know a good way to measure a device like this, to yield a curve light Nelson put in the published document? Obviously, I don't have one of the pro "AP" analyzers.
For my general education, are balanced connections typically +6dB compared to a similarly set up single-ended?
Thanks
Does anyone know a good way to measure a device like this, to yield a curve light Nelson put in the published document? Obviously, I don't have one of the pro "AP" analyzers.
For my general education, are balanced connections typically +6dB compared to a similarly set up single-ended?
Thanks
@mfeif I don't know which miniDSP-HD unit that is. That's why I mentioned it. miniDSP has/had multiple ones that have different output voltages.
You can perform a test on your ASP using any decent USB sound-card and a program like ARTA.
Yep, balanced connections generally will have 2x or (+6db) voltage relative to unbalanced.
Dave.
You can perform a test on your ASP using any decent USB sound-card and a program like ARTA.
Yep, balanced connections generally will have 2x or (+6db) voltage relative to unbalanced.
Dave.
Thanks Nelson.
I'm LOVING it so far.
By settings, you means tweaking the R, C values?
I have been informed that the article disappeared from the FW site, but here is the news address:
https://www.firstwatt.com/wp-content/uploads/2023/12/art_lxmini-crossover.pdf
Also, attached are three of the MicroCap simulation files for LX-mini, some of which you may
not have seen before.
np
https://www.firstwatt.com/wp-content/uploads/2023/12/art_lxmini-crossover.pdf
Also, attached are three of the MicroCap simulation files for LX-mini, some of which you may
not have seen before.
np
FYI VFET R0 article also disappeared from FW. DIYAUDIO store says the link is fixed, it is not.
Have the kit since 2018, but life has it's own path and i'm trying to finish what i started back in 2017.
I have a PAP trio clone OB with Markaudio 10.3 and eminence beta15. The baffle is 54cm wide. I have the system running since 2020 with a miniDSP crossing at 550hz but i always felt that the medium frequencies were lacking something. I tried to cross at 250hz and the result was better to my ears. However, after 4 years listening i always felt the need for more bass and body to the sound.
The amps are the vfet part 2 and a diy 100watt A/B amp after a BA3 preamp.
What path to pursue?
Fill the ACN with the parts for the lx mini and build the lx mini speakers, or change the crossover and adapt?
I think my listening space is not the best for the OB PAP. They are 60cm from the wall (can't move them) and i'm 3.5meters far from them.
Thank you
I have a PAP trio clone OB with Markaudio 10.3 and eminence beta15. The baffle is 54cm wide. I have the system running since 2020 with a miniDSP crossing at 550hz but i always felt that the medium frequencies were lacking something. I tried to cross at 250hz and the result was better to my ears. However, after 4 years listening i always felt the need for more bass and body to the sound.
The amps are the vfet part 2 and a diy 100watt A/B amp after a BA3 preamp.
What path to pursue?
Fill the ACN with the parts for the lx mini and build the lx mini speakers, or change the crossover and adapt?
I think my listening space is not the best for the OB PAP. They are 60cm from the wall (can't move them) and i'm 3.5meters far from them.
Thank you
Attachments
Do both and decide later 😉
In my OB builds I have certainly not missed body to the sound. One system which is now owned by a friend, is with the Lii F15 and the Beta 15's.
But you won't get the punch-in-the-chest sound that we have grown used to from box speakers.
Something you could try out is adding a coil for 6 dB filter at 150-250Hz on just one (lower) unit in the MTM, to better fill in on the low end - and to take advantage of the series resistance impact on the Q. That will give an extra fill in.
And then run the other unit to the higher cross point. But you want to cut off the break ups of the Beta with a steeper filter or low pass shelf, not to clutter the midrange.
A good choice can be an I-core coil with not too low series resistance.
If you haven't done already: Be generous with the low end lift in the DSP. After many years with passive filters one might be a bit shy towards >6dB correcttions. You are more likely to need 12+ dB. Especially if you are with-out "wings" on the baffle.
Do check the time alignment between the units and correct that in the DSP, that can also align thing in the midrange area.
All that being said... the 60cm to back wall is not optimal, are you allowed diffusers behind the speakers? Some have a bit of an artistic effect to them right? 😛
The mini's are more likely to thrive in those conditions.
They will have a better 3D rendering unless you have been exceptionally lucky with the directivity match of the units.
Thank you for your insights.
Maybe I'm trying to pursue something unattainable. All the years in a music environment, teaching and hearing piano, and playing with other musicians and instruments is not so easy or doable when speaking of an audio image or feel.
The Markaudio alone feels always a little bit shy regardless the crossover point. Maybe because they were not intended for this application. Those drivers you mention Lii F15 look like a lot better for the OB system.
I'm not chasing the punch in the chest effect, but i have an audio image that i need to achieve and feel. It comes from the audio track "Rex tremendae" from the Requiem in D minor - Mozart - Leonard Bernstein and Rundfunks orchestra. In the beginning it has a Tutti chord from the pipe organ. It's something incredible along with the whole requiem. I think the frequencies i'm talking about are only doable with subwoofers. That's why i was thinking of changing direction to the lx mini speakers and later add the +2sub.
Can you explain better what you mean about the break ups of the beta speakers?
When i first calibrated the speakers for a flat response, i used the umik1 and REW with the miniDSP. The overall result was a response with +/- 5db along the spectrum. However, i felt there was something missing even if i tried other crossover points/shelfs/notchs/.
This past years they were working ok. Some days ago i decided to finish the ACN but at the same time i decided to try other combinations for the OB. I found out that, for my ears, crossing at 250hz brings some more information that i felt missing. Maybe because the Markaudios are filling the space. The downside is that the beta15's reveals a more boominess and undefined character, if that's the better way of saying it. Still trying to identify how to explain it better with the words i often read here. It's over my league.
In the end, i want to enjoy music, and sometimes movies, but with all the background i have in music i feel that i'm miles away from the audio images that sometimes i read in the forum. I know that designing and building speakers and amps is a long way and path to achieve an holy audio image and in the end, our ears are not the same when we started to paint and imagine how the sound should be.
Sorry for the long text.
All the insights and ideas are welcome. Thank you
Maybe I'm trying to pursue something unattainable. All the years in a music environment, teaching and hearing piano, and playing with other musicians and instruments is not so easy or doable when speaking of an audio image or feel.
The Markaudio alone feels always a little bit shy regardless the crossover point. Maybe because they were not intended for this application. Those drivers you mention Lii F15 look like a lot better for the OB system.
I'm not chasing the punch in the chest effect, but i have an audio image that i need to achieve and feel. It comes from the audio track "Rex tremendae" from the Requiem in D minor - Mozart - Leonard Bernstein and Rundfunks orchestra. In the beginning it has a Tutti chord from the pipe organ. It's something incredible along with the whole requiem. I think the frequencies i'm talking about are only doable with subwoofers. That's why i was thinking of changing direction to the lx mini speakers and later add the +2sub.
Can you explain better what you mean about the break ups of the beta speakers?
When i first calibrated the speakers for a flat response, i used the umik1 and REW with the miniDSP. The overall result was a response with +/- 5db along the spectrum. However, i felt there was something missing even if i tried other crossover points/shelfs/notchs/.
This past years they were working ok. Some days ago i decided to finish the ACN but at the same time i decided to try other combinations for the OB. I found out that, for my ears, crossing at 250hz brings some more information that i felt missing. Maybe because the Markaudios are filling the space. The downside is that the beta15's reveals a more boominess and undefined character, if that's the better way of saying it. Still trying to identify how to explain it better with the words i often read here. It's over my league.
In the end, i want to enjoy music, and sometimes movies, but with all the background i have in music i feel that i'm miles away from the audio images that sometimes i read in the forum. I know that designing and building speakers and amps is a long way and path to achieve an holy audio image and in the end, our ears are not the same when we started to paint and imagine how the sound should be.
Sorry for the long text.
All the insights and ideas are welcome. Thank you
Don't be, I'm also not in the position to complain about long texts 🤣
Thank you for the added insight - it makes perfect sense and I do think I understand what you are looking for.
My apology if the following is fully ot partly already well known to you:
The break ups, is where the membrane start to "break-up" and you get huge resonance peaks, they are quite prominent at 2k - and I expect already starting lower. But the curve smoothing below is already quite substantial, which will hide that.
Look for the impedance curve "kinks", these reflect the behavior of the mechanical system and directly reflect system or speaker "issues"
Beta15:
The kink at around 1k is typically related to the suspension though.
But at 2k, you need a filter that is able to push this way down - as in 30dB, if you don't want that to mix noticeable with the Markaudio.
That will of course be noticeable when doing a umik sweep on the woofers alone to see what damping you actually get out of band.
The F15 works really well with the Beta15, I initally tried to match these up tp AE dipole 15's and it was not a match made in heaven.... the lack of sensitivity was problematic and they did not blend particularly well. The F15 comes with its own challenges - classic whizzer cone, with lots of lobing and some extraordinary resonance peaks, that needs to be tamed - without taking away too much. In the end the concept is mech. amplification by resonance ;-)
Are you running the low end lift as a peak filter?
As tempting as that might be for; "hitting two birds with one stone" = Getting both a strong lift and a good filtering against hitting the excursion limits on the units - I'd rather advice against it, you get a peak filter resonance (booom), and a "honk" character. On the positive side it can feel more "punchy".
Much prefer the low end clarity of a low shelf, without the ringing.
But in the end these things are all down to personal preference. - Not to mention whatever room modes people are trying to work around ;-)
Yes, that would work with LX521 and also the LX-Mini with added +2 sub's. I've run mine in the studio setup. But also with only one set of the units active - currently a friend has borrowed mine and run it like that as a reference to the +2 setup.
With you music background.... one of my good friends brought three good colleagues all musicians or with a background in that. To hear the LX521's and the LX-Minis/studios. They all went and build LX-Mini +2's
And, trying hard to stay on topic - there is also the "beast of 100's of JFET's" Nelson Pass designed LX-Studio/LX-Mini +2 crossover.
I soldered it all up some years ago - yet to power it up, oh dear....
N.B: With a bit of modification the LX ASP might actually work for your OB's