I think that the more insightful and civilised part of the world is leaving these attitudes... and also stops repeating anecdotes like this...
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There is very little difference in bass frequencies between channels in this video. All localization queues are from higher frequencies. I extracted audio for 3rd minute of the video and applied a low-pass 100Hz filter:
Dropbox - bassfrom3to4.mp3 - Simplify your life
It sounds almost mono.
Hell ya!!! Bad ***! lol, now heres the issue...if you listen to this track with mono bass, it still will sound pretty cool....but you'd never know it was in stereo.....if you didn't have stereo subs (I do).
I think its ideal to have a stereo image all the way through out the range but its obviously not a requirement.
Thanks for sharing that, there are songs out there with stereo bass information too, like said....you can't hear it if you can't play it.
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I loaded you file into my DAW (Ableton Live) and the stereo signal is absolutely visualized in the signal....
dude.... very little difference is enough to create a completely noticeable effect in the stereo field (exactly what comes across my stereo, playing your low passed sample, and it sounds cool)....the signal levels differences from LR may stay within a few db's but you are not considering that changes in phase between the two channels is not going to show up as levels, but generally to say that only a little difference in bass between the channels, without considering phase, especially in regards to bass, is naive. The effect is completely audible on my system,(low pass included) but I have stereo from top to bottom....
Its probably your system.
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I tried this with headphones, and the strongest effects are between 10-22 seconds in your low passed version.
So going back a few pages, and looking at the pdf spec sheets for them, what are people's views on the Celestion horns that are available for the Axi2050?
Would they give a good domestic room listening experience, albeit not crossed as low as 300Hz? Probably looking at crossing at 450-500 Hz to a 15" in a BR enclosure with an active sub or two from 45-50 Hz down.
Would an Autotech EJMLC or similar be a better bet in this situation?
Keith.
Would they give a good domestic room listening experience, albeit not crossed as low as 300Hz? Probably looking at crossing at 450-500 Hz to a 15" in a BR enclosure with an active sub or two from 45-50 Hz down.
Would an Autotech EJMLC or similar be a better bet in this situation?
Keith.
Well I have the Axi on a 200Hz JMLC over an OB 18" at present which is fine as it's in a dedicated room.
However, we are 80% certain to be moving and the hifi will be going in the living room so I need horns that are better finished such as the Celestion ones or Autotech. My wife is ok with the look of the Celestion and they only come in black now but wondered how good they will sound if anyone can judge that from the polar plots posted earlier in the thread. The Autotech EJMLC is also approved and I wondered if this would be better?
Celestion will go down to 400Hz and the EJMLC300 has a lower cut off of 500Hz according to the website so I would be looking to put a 15" in a BR cabinet as I wouldn't want to take the Fane Colossus 18XB up to 400 or 500.
What are good combinations of horn for the Axi and which 15" in which BR cabinet?
Is the present 320Hz too high for the 18" XB anyway so will be better to go for 15"?
If the 18" XB would not be bettered by a 15" what alternative horns are there out there for the Axi? Has Joseph Crowe made his prototype for the Axi yet, how low will it go and more importantly how much shipped to the UK??!!!!!
Lots to ponder and a head full of magic
!!!
Keith.
However, we are 80% certain to be moving and the hifi will be going in the living room so I need horns that are better finished such as the Celestion ones or Autotech. My wife is ok with the look of the Celestion and they only come in black now but wondered how good they will sound if anyone can judge that from the polar plots posted earlier in the thread. The Autotech EJMLC is also approved and I wondered if this would be better?
Celestion will go down to 400Hz and the EJMLC300 has a lower cut off of 500Hz according to the website so I would be looking to put a 15" in a BR cabinet as I wouldn't want to take the Fane Colossus 18XB up to 400 or 500.
What are good combinations of horn for the Axi and which 15" in which BR cabinet?
Is the present 320Hz too high for the 18" XB anyway so will be better to go for 15"?
If the 18" XB would not be bettered by a 15" what alternative horns are there out there for the Axi? Has Joseph Crowe made his prototype for the Axi yet, how low will it go and more importantly how much shipped to the UK??!!!!!
Lots to ponder and a head full of magic
!!!Keith.
I’ve learned a lot from your experience so far. I am wondering what our dear AXi sounds like it’s lower register without the assistance of loading. I’m building with the interest of having the horn load down to the lowest register I intend to produce...I’m wondering what 300hz sounds like from this driver, on an 600 or 800hz horn. Several people have commented that loading isn’t an issue for compression drivers at home levels .... I believe that having loading sounds better but in sacrifice for the wide polar and possibility of keeping the low xover, you never know till you know....you know?
Yes
Camplo, I have added some textbook crossover slopes onto the Axi2050 in a JMLC 250 Horn measurement to give you an idea of what they look like. The rolloff shown in the bare measurement is very close to LR48 300Hz, for comparison there is an LR24 at 300Hz. I think 300Hz is quite achievable with that driver, 200Hz would be more of a stretch and could be output limited if that is an issue. The impedance peak shown on Celestions website on their horn is around 250Hz so pushing below there might be more problematic.
They used a Seos 30 horn. That horns length is 12" the QW of ~282hz and with that flare, there is no way this horn is loading anywhere near that. On their chart there is a dip in the impedance centered around 400-450hz....I think thats very telling. I bet if I trace the pwt impedance line into watchamcallit and then create a filter to make the response look like the impedance on the horn, I could imitate horns of different tunings, worth a try.
Fluid, I was actually looking for your post on diffraction and how you think I should focus on that some. A smart person told me to copy things that other people are doing right, the only model that comes to mind is the Geddes creations.... The horn is already going in the right direction, the first idea that came to mind for the driver baffle is 3d printer...thats as far as I got so far lol!
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Hmm, thought I had........
Oh well, regardless, what's to discuss?
I mean when something as compliant as a 'slug' of a sound 'bubble' with an air mass 3x longer/more massive than what's in the pipe is oscillating at the speed of sound [SoS] ['tail wagging the dog', so to speak] it takes a significant amount of physical disruption to damp it.
This is at the wrong end of the horn, so is an inverse [expanding instead of a contracting] example of what's required [an example of Olson's 1940? BLH studio monitor [pgs 46-47]]: https://www.americanradiohistory.com/Archive-Poptronics/60s/62/Pop-1962-10.pdf
Now in your mind, scale up the rows in size to in between these smaller ones and the two panels plus all the volume that constitutes the horn's bass expansion.
From this, doesn't my simple expedient of using a tube vent to fine tune/'critically' damp the box, regardless of type, seem the best overall acoustic solution?
GM
edit: Guess I should have just said tack on the end of slightly truncated 1/4 WL TL a properly folded labyrinth equivalent of at least an Av = Sd area of whatever resonant frequency is required to get the desired downward shift of Fb[p] and Qtb[p].
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There's isn't much that isn't worth a try if you have the time to do it
What do you think is telling and about which dip?What I see in the impedance traces shows what I was trying to tell you before, the resonant frequency hasn't changed all that much between the two, it is more highly damped and spread out on the PWT measurement. Any practical horn is going to look much more like the seos measurement than the PWT.
I have seen a lot of ABEC simulations of different baffle treatments and they all show that taking care of the transition from speaker to baffle and the edge of the baffle makes a big difference in reducing diffraction. This is the reason Earl Geddes does not like unbaffled horns, even with a massive rollback the other edges nearby create sources of diffraction that a straight out simulation of the horn will not show. Changing slowly from one point to another as smoothly as possible is the goal. Angled faceted baffles can get surprisingly close to a big radius and are much easier to construct out of wood if you have the tools, or cheaper to have someone else make for you.
Making all the parts out of a 3D printer and getting them to be straight and accurate is an extremely difficult task. If it was me I would be looking for a hybrid construction to make that task easier.
Yeah you took me from A to F and then say whats to discuss lol! Maybe its been way too long since you knew nothing about speakers. Either way......Thank you. I'll be able to adjust fill to taste thanks to the physics you just described. I also have been able to interpret how the end of my folded line will perform. Like you said, the steps are not very significant, though they will add a small effect of length, if only a few CM's and the added restriction of the steps won't really move FR but may have a positive effect on group delay. My folded box is not anticipated to be an exact replication, but it still has the advantages of the discipline of the box you first submitted. My folding is not unique either, its the same folding used to create a J scoop...in inverse... GM you saved me.