The 240cm is already the lower limit of what is useful.
The Alta Voce would be an excellent alternative that also works well at distances of less than 250 cm:
https://www.donhighend.de/?page_id=8971
https://www.der-akustische-untergrund.de/speakers/power-hifi-projects/asathor-preiswerte-männerbox/
Scroll down close to the bottom. There you have "Bauplan" as a PDF download
Scroll down close to the bottom. There you have "Bauplan" as a PDF download
I spoke with the designer of the Alta Voce and his experience is that the listening distance should be fine.
He suggested that most likely the issue is the stock crossover that is used in the Celestions.
" Perhaps your listening impression is caused by a suboptimal tuning of the crossover. I think that’s the problem. The horizontal off axis measurement in the data sheet shows that too much energy is being transferred into the room in the area marked by me. It also seems to me that the upper treble range beginning at 5kHz is too loud."
I think he has a valid point. This original crossover is probably designed for maximum sensitivity.
Now I see 2 options here:
Option 1: Redo the crossovers
Pro: Cheapest option
Con: Designing a crossover without experience (never done before)
Also my UMIK 1 is probably not good enough to do this.
Option 2
Build the Asathors
Pro: Tested and tried with good measurements and documentation.
Con: More expensive + ported box
@Rese66 would the crossover work if I put the Asathor in my Celestions cases that I currently have?
I could reuse that and also the horn. The box is of course slightly different dimensions than what the original Asathors are
Internal Volume: 76L
Port Tuning Frequency: 55Hz
Dimensions: 730 x 452 x 342mm (H x W x D)
The 2 bass drivers seems to be very similar in performance.
My WINISD simulations shows very similar performance for these 2.
The LaVoce might actually be slightly better.
Any thoughts and suggestions are welcome.
NO .... Stop. You are waaaaay off track. You can't put parts of a complete design (Asathor) into a different sized/loaded enclosure.
It's a perfect design as is. Build them and enjoy.
I understand that viewpoint, however I have a specific use case, why I am pursuing/pondering this route.
My speakers is not standing freely, but used behind a acoustically transparent screen.
This means the Asathor is simply too tall to use in my listening area as the acoustical center will be to high.
Box dimensions are not that different.
Width = Asathor: 440 / Celestion : 452
Depth = Asathor 340 / Celestion 342
Height = Asathor 986 / Celestion 730
I have understood that height does not affect baffle compensation, but width does.
They are using different drivers, but the concept it very similar.
I am not trying to improve it, just trying to adapt it for my use.
In Rese66 instructions he was recommending experimentation, so this is why I am wondering.
So thats why I am asking here for advice how to proceed.
My speakers is not standing freely, but used behind a acoustically transparent screen.
This means the Asathor is simply too tall to use in my listening area as the acoustical center will be to high.
Box dimensions are not that different.
Width = Asathor: 440 / Celestion : 452
Depth = Asathor 340 / Celestion 342
Height = Asathor 986 / Celestion 730
I have understood that height does not affect baffle compensation, but width does.
They are using different drivers, but the concept it very similar.
I am not trying to improve it, just trying to adapt it for my use.
In Rese66 instructions he was recommending experimentation, so this is why I am wondering.
So thats why I am asking here for advice how to proceed.
Ok then... in that case:
Seal the ports, period.
Measure the difference in volume.
Build the proper volume sized box to attach to the sides or rear of the smaller enclosure (like a wart).
Cut out a 3" hole in your enclosure.
Place "wart box" over the hole and glue/screw it down.
Now your speakers aren't too tall, but they have the correct air space. Looks doesn't matter because they're behind a screen.
Seal the ports, period.
Measure the difference in volume.
Build the proper volume sized box to attach to the sides or rear of the smaller enclosure (like a wart).
Cut out a 3" hole in your enclosure.
Place "wart box" over the hole and glue/screw it down.
Now your speakers aren't too tall, but they have the correct air space. Looks doesn't matter because they're behind a screen.
Fortunately, closed speakers are not very sensitive to slight deviations in volume.
Here is a simulation showing the difference between the original 90L and your ~75L:
As you can see, there is hardly any deviation and the high-pass capacitor further reduces the differences.
The deviating dimensions are also not dramatic in this case, because the width in particular only differs very little.
I would also close the port in any case. However, it may be that you have already become very accustomed to the sound of your Celestion with the clearly emphasized upper bass and that it doesn't seem enough to you.
Just put a towel in the port and close it to test it, then you'll see how the bass range changes.
Here is a simulation showing the difference between the original 90L and your ~75L:
As you can see, there is hardly any deviation and the high-pass capacitor further reduces the differences.
The deviating dimensions are also not dramatic in this case, because the width in particular only differs very little.
I would also close the port in any case. However, it may be that you have already become very accustomed to the sound of your Celestion with the clearly emphasized upper bass and that it doesn't seem enough to you.
Just put a towel in the port and close it to test it, then you'll see how the bass range changes.
@Rese66, thanks. I think I will test it. I am using Dirac Room EQ with it, so it flattens out that midbass hump very nicely. Low bass are handled by subs, so extension to 70 hz is plenty. My listening room is a open plan wooden house, so it provides little room gain. My simulations showed that they (Celestion and LaVoce ) will perform very similarly in my current box. Actually the LaVoice slighlty better !
To close the speakercase box should also not be a problem. I was thinking to just add a new front plate, if need be. You mentioned in the original article that you tested some Celestion compression drivers for this project.
Which one?
I am currently using SBacoustics coaxials for surround. Do you have any suggestions for DIY horns speaker design that can be used as surrounds? I have a hunch Dirac will do a better job if the speakers have similar dispersion patterns.
To close the speakercase box should also not be a problem. I was thinking to just add a new front plate, if need be. You mentioned in the original article that you tested some Celestion compression drivers for this project.
Which one?
I am currently using SBacoustics coaxials for surround. Do you have any suggestions for DIY horns speaker design that can be used as surrounds? I have a hunch Dirac will do a better job if the speakers have similar dispersion patterns.
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