Is it possible to cover the whole spectrum, high SPL, low distortion with a 2-way?

I also have the limiter set at 10watts...and some other settings tweaked in efforts to protect the driver (first time ...)...but I wasn't watching those meters when running measurements...I will try again without any limiters on to make sure I didn't augment the measurement....maybe I can run it with no crossover as well...Either my amp is faulty or I keep triggering something...time will tell.
 
How do I tell when I am reaching xmax (asking for 100th time)

Heres some more measurements at the horn mouth no XO....
Assuming you are asking about the Xmax of a high frequency driver, when second harmonic distortion reaches around 10%, probably close to Xmax at the Fc (lower horn cutoff frequency).

When running a HF driver down low, Xlim (the diaphragm hitting the phase plug) is more of a concern.
The clickety-clack sound of the diaphragm hammering the phase plug will decrease in speed at lower frequencies, but the distinctive sound won't be multiples of the fundamental as in harmonic distortion.

I can't tell from your labels what any of the measurements are, though obviously most of them include various processing. Response at the horn mouth isn't great at predicting response at a real world listening distance, unless you are planning to use the horns as "Texas Headphones" ;)
That said, looks like the horn/driver combo has an Fc around 350Hz, making it to around 2kHz before dropping off at 6dB per octave. Will be interesting to see what the 600, 900, 2kHz, 4kHz "bumps" do at a few meters distance, and off axis.

If you have questions, posting the specific measurements would be helpful.

Cheers,
Art
 

Attachments

  • Sizzle and Dull.png
    Sizzle and Dull.png
    151 KB · Views: 369
OK thats my fault, I selected save all measurements....In my mind that meant group delay/fr/phase etc lol

In the last measurement I have measurements from a 4" mid a 1" tweet and a whole bunch of other random stuff that was never supposed to be in the mix...my apologies

Here
AXi350hznoXO.mdat - Google Drive
You should find one single measurement minus any processing....this is a measurement that was in the mix of previous files...so it is still at horn mouth...I'll try to get some more data to share today.
 
an mid-high array of small drivers (on-wall - which gives additional ~6 dB of dynamic range) and a woofer that is boundary coupled (additional ~12 dB of dynamic range), crossed around 300 Hz, is a viable alternative IMHO


You would have to elaborate on the mid array aspect...crossed where I'd wonder.. and the outcome would have to keep the tweeter at ear level.
 
I've been told that horn alignment to compression driver is very important...anyway to tell within the measurements if it is off?
Yes, measure the misaligned compression driver/horn, then align it, and compare the two.

A misalignment will cause throat reflections, making frequency response more ragged, and add some decay time. The smaller the misalignment, the higher the frequency that a difference would be visible or audible.

If you can't see the throat, using a piece of bent wire as a "feeler" you should be able to detect any misalignment as a "step". If you can't feel a bump, no need to worry about it.
 
Using a wire as feeler I’ve discovered a 4mm offset from the gasket opening radius but the gasket radius as not in “brand new” status...I think it is warped...I reseated it’s several times but I think the whole is off...do I have to use the gasket and good look on getting a new one lol...it’s confusing...there’s no 4 mm offset to reflect on the opposite side of hole...measured radius of horn and gasket holes...everything seems to be right..I did notice the exit angles aren’t what I’d want them to be...
 
Last edited:
OK major noob alert.....I dunno....it seems like if it don't fit one way... it won't fit the other....I played around with the gasket a little and tried reseating the horn...took one rotation...or where ever it landed when I put it back (and I got it seated perfect)...I used an engineers ruler to measure the holes on horn and gasket...gasket is dead nuts 2"....horn is 1" - 31/32....but the exit angle is not 0...how I overlooked this one aspect is sad...but it is not the end...I looked back through my conversations (with the horn builder) to see if and when I brought up exit angle and could not find it...why would I assume the exit angle would be 0 is beyond me...am I not viewing this topic right? If the exit angle of the Axi is 0 degrees...thats flat right?...so I would want the horn exit to start on the same vector right?

I can say at this point that the horns appear to be of high quality (now that I've got the throat lined about perfect)...for hand made custom wood assembly...I'd definitely use their services LMH

Shameless plug there...they have won my affection for building a custom horn in the future....In the mean time I know that I will enjoy what I have....I ran some test tones today.....350hz at ~115db at 1 meter...~140 something db at the mouth...I was going to share them but my 4 year old decided too many windows were open in my absence and closed out REW....those measurements probably include some kind of room gain is my guess? seemed to be modal... Room eq at 350hz really?

I thought I understood amplifiers well enough....so confused how this amp should be 2000watts rms...but yet I can only get so much volume after subtractive eq and high pass....and when I run test tones through REW I get much more volume than running VLC and mp3's? Makes no sense. Guess I'll get there slowly but surely... Not sure how accurate my measurements are but that 350hz test tone was much louder than I'd be playing it at nearfield and that was just one driver going so I am very confident, so far, about crossing at 400hz.....or basically as low as 350hz as long as system group delay stays in check......with a 350hz horn...I compared the spectral decay to that of a krk kevlar 4" and they were very similar.....the group delay of the resonate tail of the horn was the one major difference.

Hopefully more progress tomorrow.
 
Last edited:
attachment.php


The volume between 400 and 2khz are similar though my measurements are at the mouth of the horn the measurements of the ATC sm75 are at 9"....in that small range you get reference and with distance accounted for, the magnitudes are similar in that area. I'm not sure if the distortion figures can be compared.
I think I used a 400hz 6db/oct xo and some eqing? I initially wanted to compare the resonant character of each...I cant say they are miles apart. Spectral graphs are set up for -25db
 

Attachments

  • Idhitthat.jpg
    Idhitthat.jpg
    382.9 KB · Views: 1,157
Last edited:
You would have to elaborate on the mid array aspect...crossed where I'd wonder.. and the outcome would have to keep the tweeter at ear level.

Take a look at the Gryphon Pendragon - basically it's a two-way, the ribbon covers the range from 300 to 18k, AMTs work as a supertweeter miniarray.

I am thinking about substituting the ribbon with a long array of suitable small widerange drivers that can go low enough, that is 200<300. I am sure there are suitable drivers on the diy market.

The midtweeter array could be flat on-wall, for greater dynamic range and easier integration with bass towers
 
Last edited:
I'm not sure what "on wall" means...but I think you just mean on the front baffle?

I got around to hooking up the DATS....below is the impedance I believe...I wonder if i play with mass and driver sd figures if I'll get readings on the rest of the specs?

What do you guys thing? Take the Axi apart so I set some mass on the diapragm? :headshot:
918271d1612337315-cover-spectrum-spl-low-distortion-2-a-axi-impedance-jpg
 

Attachments

  • Axi Impedance.jpg
    Axi Impedance.jpg
    276.9 KB · Views: 660
Last edited:
theres a post somewhere on the internet with several compression drivers compared...

Impedance and spectral decay were shown and i think some older jbl Be drivers were in the mix....I'd love to compare my measurements... of course can't find it now...anyone got a link to any measurements I might compare?