Hello everyone. I am new to this forum. I have just started working on a final project for a subwoofer. I am trying to use dedicated software, but they are all too professional for my skills.
I have read everything I could about the BMS 18N 862. And it seems like the perfect candidate. I will have to make a pneumatic suspension (closed cabinet) with not very high SPL. Let's say 100/103 MAX, in 90% of the use they will be at 78/90DB. I will use only 1 driver.
However, I would like it to reproduce linearly from 20 Hz to 100/300 (depends if the bms sounds better than my pl200 audio monitors) from 100 Hz up. I have two powersoft litemod modules as final amplifiers. One in bridge mode allowing a rms power of 1200 W and the other 600 W per channel for 2. Both connected to its Loto DSP.
The idea is to drive the subwoofer with the bridge module, and the woofers of my pl200 from the 2-channel module. So as to have 3 total channels.
While for the high channels I will have a Purifi ET400A (eval 1) without dsp.
The question is: I have read a lot about this subwoofer and I have doubts about the usability. I would lean towards a capacity of 125 liters. The parent company suggests 100. But do you mean 100 liters net or gross? Because from the software simulation it changes a lot. 100 liters net will be about 130 gross.
The room is 5x5 meters. Height 3MT
I have read everything I could about the BMS 18N 862. And it seems like the perfect candidate. I will have to make a pneumatic suspension (closed cabinet) with not very high SPL. Let's say 100/103 MAX, in 90% of the use they will be at 78/90DB. I will use only 1 driver.
However, I would like it to reproduce linearly from 20 Hz to 100/300 (depends if the bms sounds better than my pl200 audio monitors) from 100 Hz up. I have two powersoft litemod modules as final amplifiers. One in bridge mode allowing a rms power of 1200 W and the other 600 W per channel for 2. Both connected to its Loto DSP.
The idea is to drive the subwoofer with the bridge module, and the woofers of my pl200 from the 2-channel module. So as to have 3 total channels.
While for the high channels I will have a Purifi ET400A (eval 1) without dsp.
The question is: I have read a lot about this subwoofer and I have doubts about the usability. I would lean towards a capacity of 125 liters. The parent company suggests 100. But do you mean 100 liters net or gross? Because from the software simulation it changes a lot. 100 liters net will be about 130 gross.
The room is 5x5 meters. Height 3MT
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If you want a definitive subwoofer project, have you considered a multisub setup? A single sub, no matter how good the driver, interacts poorly with the room.
I will do it in the future. At the moment I don't have room for 2 units. Not even for two 12" subwoofers, I rule it out from the start in terms of diameter.
And I need a little time to scrape together money. I would start with one.
The idea is to have 2, and then build a three-way on top.
And I need a little time to scrape together money. I would start with one.
The idea is to have 2, and then build a three-way on top.
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Sorry, but why you are using the very expensive BMS driver, if you are short on money? There are several cheaper alternative, and you can Save money on the amp too (ni need for purify?).
because little by little I have to create definitive speakers.
Purifi I consider it an excellent amplifier. At least from the specs. In the past I have owned two monophonic parasound JC1s. I would like to get closer to that audio quality.
Purifi I consider it an excellent amplifier. At least from the specs. In the past I have owned two monophonic parasound JC1s. I would like to get closer to that audio quality.
BMS suggestion of 100 liters is the net volume. The volume occupied by the driver (~10.5 liters depending on front or rear mounting) and bracing is added to the net.
Adding 25 liters will slightly lower the -3dB point from 50Hz.
Using your DSP, you can equalize it's response to flat (linear) from 20-100Hz, a larger cabinet of 125L using slightly less EQ and power in the low end boost.
With no room or boundary gain, the single 18" BMS 18N862 should be able to reach around 107 dB at one meter at 19mm excursion.
Depending on placement, that much output probably will exceed your 103 dB maximum level.
Not sure what your monitor drivers are, but assuming four sealed 6.5" with 8mm excursion, they could do ~94dB at 20Hz.
The 18N862 could easily sound over twice as loud at 20Hz.
I don't know. From the environmental measurements, 95db max would be enough for me. I can equalize everything to make the response homogeneous.
@weltersys
my speakers are the first platinum series from monitor audio. They have 2 drivers per speaker of 6 inches. The speakers do not go below 35hz.
In the past I bought a 12 inch monitor audio silver rxw subwoofer used. Then it broke after only two weeks. It had an annoying hump at 50/60hz and had a lot of difficulty going down. So I decided to build myself a serious subwoofer. Because the body that it gave to the music was pleasant.
my speakers are the first platinum series from monitor audio. They have 2 drivers per speaker of 6 inches. The speakers do not go below 35hz.
In the past I bought a 12 inch monitor audio silver rxw subwoofer used. Then it broke after only two weeks. It had an annoying hump at 50/60hz and had a lot of difficulty going down. So I decided to build myself a serious subwoofer. Because the body that it gave to the music was pleasant.
Yes, if you want a net internal volume of 100L, and the driver occupies 10.5 liters, the bracing 4.5 liters, the gross interior volume would need to be 115 liters.
Conversely, adding stuffing material (polyfill, fiberglass, wool, etc.) can increase the apparent net volume by ~15%.
Conversely, adding stuffing material (polyfill, fiberglass, wool, etc.) can increase the apparent net volume by ~15%.
What did you individually calculate adds 30 liters to the net volume to equal 130 gross?
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Haven't used Bassbox.
My bet is the volume of the exterior box walls and of the baffle is close to 30L.
Does Bassbox start with exterior walls and their thickness?
My bet is the volume of the exterior box walls and of the baffle is close to 30L.
Does Bassbox start with exterior walls and their thickness?
The net volume is the volume available for the drivers. So: No, because these volumes are not actual 'usable' net volume.
you are right. It is not bassbox, but subbox.pro online. Since I am not an expert I think I messed up a bit. There is an entry to add in the program that calculates the volume of the driver. But I do not know where to get it. I report the wording:
it says: woofer movement.
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I couldn't get subbox.pro to work properly, so have no idea how it calculates driver volume.
The volume occupied by the driver can be a negative number if mounted with the magnet outside the box.
The BMS 18N862 spec sheet does not indicate the volume of the driver, so I suggested the volume of a similar size driver, the B&C18SW115 (10.5 liters):
The BMS 18N862 certainly does not occupy 31 liters (156 total internal volume - 125 net internal volume=31).
Anyway, the box should be braced, which occupies some volume in addition to the driver.
Art
I considered the reinforcements.
So if I make a classic sealed box (with the internal magnet) of 140 liters gross I should have approximately 120/125 liters net. I would say that for my room it is too much. but for the driver it is perfect.
having a digital dsp, in Q to keep with this liter I imagine that it is not 7.07. Right? But can I take into account via dsp 7.07 Or do I have to stick to another coefficient?
So if I make a classic sealed box (with the internal magnet) of 140 liters gross I should have approximately 120/125 liters net. I would say that for my room it is too much. but for the driver it is perfect.
having a digital dsp, in Q to keep with this liter I imagine that it is not 7.07. Right? But can I take into account via dsp 7.07 Or do I have to stick to another coefficient?