Thanks Toni. BTW can we see your scanspeak sub images for better detail ?
To shrink cabinet volume adding braces and corner blocks does both positives.
Also doubling wall thickness on open walls if its possible. Only if it can be done where it makes sense.
You can never make a box too strong.
You can only do so much with such a large box. Adding a second seas a way to go .
But that may cause some headaches for you to tune. Going to the drawing board and creating two new smaller sealed cabinets would be my choice. Experience tells me everything will improve x2. System integration, smoother, more balanced bass thats easier to tune. I get away with no EQ at all just a simple analog crossover and I'm fully happy with results currently with similar. I run this way for years with dsp. But I used to run ports. No more ports for me I might never go back
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Theres some work involved yes but there's enough positives to make it worth doing.
To shrink cabinet volume adding braces and corner blocks does both positives.
Also doubling wall thickness on open walls if its possible. Only if it can be done where it makes sense.
You can never make a box too strong.
You can only do so much with such a large box. Adding a second seas a way to go .
But that may cause some headaches for you to tune. Going to the drawing board and creating two new smaller sealed cabinets would be my choice. Experience tells me everything will improve x2. System integration, smoother, more balanced bass thats easier to tune. I get away with no EQ at all just a simple analog crossover and I'm fully happy with results currently with similar. I run this way for years with dsp. But I used to run ports. No more ports for me I might never go back
.Theres some work involved yes but there's enough positives to make it worth doing.
Due to the structure of the box, I think it is viable to separate it into two sealed spaces of about 40/45 liters. Des this way you could install an additional scanspeaker in each box and have "two subwoofers in one". I must study in detail if I can actually do it since access to the interior can only be done through the wofer hole.
BR
Toni
BR
Toni
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If I manage to separate the inside of the 90-liter box into 2 of 45, do you think that would be the ideal solution?
BR
Toni
Two woofers can share the same enclosure in a sealed box. You don’t need to subdivide it.
another option will be to mount the 2nd woofer on the rear panel; so that the woofers movement are equal and opposite, and reduces cabinet vibration. This “ dual opposed” method works well, but only if your subwoofer covers under ~100Hz
whether or not it either will be ideal depends on your goals. It will depend on the perceived limitations of your system.
just remember You’re not It getting deeper bass, just more output capability, which is usually perceived as cleaner, more dynamic or effortless bass.
do you have any measurement capability at your listening position?
another option will be to mount the 2nd woofer on the rear panel; so that the woofers movement are equal and opposite, and reduces cabinet vibration. This “ dual opposed” method works well, but only if your subwoofer covers under ~100Hz
whether or not it either will be ideal depends on your goals. It will depend on the perceived limitations of your system.
just remember You’re not It getting deeper bass, just more output capability, which is usually perceived as cleaner, more dynamic or effortless bass.
do you have any measurement capability at your listening position?
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Nice looking cabinet. But no screws in there Toni? I didn't notice any construction screws. In that case I might approach the existing baffle with some type of saw and a router tool with cutting carbide. One with a bottom bearing would ride the inner walls and make a nice close accurate shave. Perhaps use a hand saw of some kind near bracing.
Hello, I have already bougth two other scanspeak subs. Reviewing the measurements of the box, I can install an additional sub for each box.
Thanks to all for the help. My only question is whether it is convenient to separate the box into two independent interior spaces or can I keep the 90 liters divided between the two subs.
Another aspect in which I would like to hear opinions is the following. The wofer of my three-way loudspeakers is also active amplified with fusion 501. The cut is at 200 hz. I don't do any undercut. Would it be better to cut the wofers and let the subs exclusively reproduce the lower frequencies (in the form of 4-way loudspeakers)?
BR
Toni
Thanks to all for the help. My only question is whether it is convenient to separate the box into two independent interior spaces or can I keep the 90 liters divided between the two subs.
Another aspect in which I would like to hear opinions is the following. The wofer of my three-way loudspeakers is also active amplified with fusion 501. The cut is at 200 hz. I don't do any undercut. Would it be better to cut the wofers and let the subs exclusively reproduce the lower frequencies (in the form of 4-way loudspeakers)?
BR
Toni
I misunderstood the first time.
That is a great idea, it looks like that is possible by your uploads.
Bonus you still must finish it.
My 1 vote is on slicing it @ close to half as possible then cap the ends off.
I vote reason being because you will be able to get them to sound better with dual separates opposed to one box x 2 subs, it opens them up and helps aids with tuning and finding solid placement. You wont have as large of node space show up and it will also help smoothen out troublesome humps.
As I was saying I have lots of playing time with both combinations.
I'd hate to be wrong because there are variables that play out. However not large enough to change how physics like to play.
If you keep a single 90L box, and load it with 2 subs, there is No advantage to have two separate interior 45L spaces.
A potential advantage of having 4 x 45L separate boxes allows smaller subwoofers which may allow easier placement in the room, and reduction of room modes causing irregular frequency responses.
Removing the midwoofers need to play below 200Hz will reduce intermodulation distortion. And thus a cleaner midrange. However, adding high pass and low pass filters and effectively creating a 4 way system is best done with measurement equipment, either automated or manual, does if on your level of experience.
It's preferred to parallel 2+ woofers which share a common volume, and avoiding a 2ohm load could be an advantage. With a series connection, the FA501 should have headroom beyond Xmax here, so divided Vb makes sense if it's practical to implement.
Simulation already completed.
I recommended series connection with shared volume:
https://www.diyaudio.com/community/threads/help-for-a-90-liters-sealed-subwofers.398877/post-7343721
I will agree to disagree regarding separate volume.
I recommended series connection with shared volume:
https://www.diyaudio.com/community/threads/help-for-a-90-liters-sealed-subwofers.398877/post-7343721
I will agree to disagree regarding separate volume.
Series connection in shared volume probably isn't that big of a problem, especially with just 2 drivers, but why not optimize everything? There was some good discussion in @fluid's line-array thread, if anyone's interested. @opc's Paradigm story makes a good starting point, with more discussion & sims following.
I might be more willing to try it if doing dual cabs x 2 subs per cab. But not when I can space those same 4 subs apart within the same room. I guess the only way to know for sure is to play out the very scenario by trying them shared then, separate the two in half. The ears always tell it.
Hello, from your explanation I understand that it is not necessary to divide the box into two parts of 45 liters. If so, much easier.
On the other hand, the 501 module allows you to connect a pair of wofers since it has two pairs of connection cables.
BR
Toni
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If you are into buying high cost damping material, you should be buying the "Unicorn Hair" rather than "Angel Hair":
"Owing to the endless fibres strings used in TWARON® Unicorn Hair, the effective functional frequency-range is lower in comparison with the TWARON® Angel Hair".
My experience with chasing unicorns has found it to be expensive...
Whether TWARON® fibers absorb acoustic motion energy in a "fundamentally different manner than other known materials" is debatable, but it appears the absorption coefficient of 20 grams per liter of "Angel Hair" filling is about that of 2" (50mm) of Owens corning 700 series fiberglass.
"Angel Hair" and "Unicorn Hair" does more absorption per weight than other damping materials, but considering it's cost per weight is around $200 per kilogram it's still no bargain.
Art
"Owing to the endless fibres strings used in TWARON® Unicorn Hair, the effective functional frequency-range is lower in comparison with the TWARON® Angel Hair".
My experience with chasing unicorns has found it to be expensive...
Whether TWARON® fibers absorb acoustic motion energy in a "fundamentally different manner than other known materials" is debatable, but it appears the absorption coefficient of 20 grams per liter of "Angel Hair" filling is about that of 2" (50mm) of Owens corning 700 series fiberglass.
"Angel Hair" and "Unicorn Hair" does more absorption per weight than other damping materials, but considering it's cost per weight is around $200 per kilogram it's still no bargain.
Art
Hello. I received the two extra subs and this weekend I was able to drill the two holes in the box and install them. So far the results are promising. I have had to lower the power output of the Hypex by 10/15%. This makes the wofers work very relieved. The membranes hardly move and the sensation is of a clearer sound and without shocks. Now it's time to experiment. See what happens if I eliminate the cut at 25 hz to protect the sub when it only had one... thank you very much to all of you who have contributed your opinion and help.
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I have a dual opposed subwoofer with the same drivers and fa501 amp it sound very good.
The drivers share a 53 liter volume with a lot of wool to have a higher Qtc.
Its recommended to make a parallel conection, the fa501 has 400 watt@2ohm but only 270@8ohm with the woofers in series
Im planning to bould another Dos subwoofer with the fa502 amp 2x500w@4ohm, then its maybe better to give each woofer his one sealed enclosure.
The Sigberg 10D subwoofer uses also Scanspeak discovery drivers and fa501 amp in parallel conection.
The drivers share a 53 liter volume with a lot of wool to have a higher Qtc.
Its recommended to make a parallel conection, the fa501 has 400 watt@2ohm but only 270@8ohm with the woofers in series
Im planning to bould another Dos subwoofer with the fa502 amp 2x500w@4ohm, then its maybe better to give each woofer his one sealed enclosure.
The Sigberg 10D subwoofer uses also Scanspeak discovery drivers and fa501 amp in parallel conection.