Hi guys
Can the above Monacor model be used for a subwoofer? I have two of them lying around after a mis-buy and I was contemplating building a slim under-bed subwoofer. It will mainly be used for films so the bass doesn't have to be very loud or overwhelming. I just need it to be felt a little when sitting in the couch. It would be a good DIY project for me.
Here is a link to the specs:
SPA-10PA
Can the above Monacor model be used for a subwoofer? I have two of them lying around after a mis-buy and I was contemplating building a slim under-bed subwoofer. It will mainly be used for films so the bass doesn't have to be very loud or overwhelming. I just need it to be felt a little when sitting in the couch. It would be a good DIY project for me.
Here is a link to the specs:
SPA-10PA
The limiting factor is the height which has to be around 20 cm's. It has to be placed under a bed which gives it 28 cm's of clearance and I would like to place it on some feet so it doesn't have to rest directly on my concrete floor.
The box could probably be 100x150x22 cm's in outer dimensions if I can stretch it.
One of my main issues is that my room is in the basement which leaves me with concrete on 5 sides and a wooden ceiling. I don't require very low bass because that would just leave me with a lot of rumble and resonance and not much actual bass. I'd much rather go for precision at a bit higher frequencies.
Edit: My previous sub is/was a Cerwin Vega LW-12X which creates way too much rumble and not enough "punch".
Edit2: I have two of these drivers, so if they can be mounted in any way to create more SPL be my guest as to enlighten me. I have build Saturnus' Boominator, where the drivers are mounted back to back which increases their respective dB levels. Could something similar be done here to achieve MOAR BASS or well, more "punch".
The box could probably be 100x150x22 cm's in outer dimensions if I can stretch it.
One of my main issues is that my room is in the basement which leaves me with concrete on 5 sides and a wooden ceiling. I don't require very low bass because that would just leave me with a lot of rumble and resonance and not much actual bass. I'd much rather go for precision at a bit higher frequencies.
Edit: My previous sub is/was a Cerwin Vega LW-12X which creates way too much rumble and not enough "punch".
Edit2: I have two of these drivers, so if they can be mounted in any way to create more SPL be my guest as to enlighten me. I have build Saturnus' Boominator, where the drivers are mounted back to back which increases their respective dB levels. Could something similar be done here to achieve MOAR BASS or well, more "punch".
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I saw it. I recognized technobabble. My head went. Can you elaborate a little bit for me?
Hi,
epa is right: Here is a suggestion:
b
Attachments
Okay, so with a horn design I could get it to have an SPL of 108 watts at 37 hertz? And the enclosure would need to have a volume of 78 liters. How about the design of the horn? I have seen some horn designs before, but I am unsure as to the angles I would have to use and so forth.
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I don't know if a horn would achieve the numbers you've posted but a T-TQWT,definitively not a horn, would do this in a single folded enclosure.
I've seen some too..thousands during at least 45 years..With various angles...
IMO, You're too quick and vague..(so forth)....
b
Okay.. I will try to rephrase. I Googled your username and the term "TH" and I found a link about horns - therefore I assumed it was a horn you wanted me to build. I have no idea what a T-TQWT is, but I will Google it.
Picarro, welcome to the wonderful world of quarter wave-I found it and am still trying to get my head round it-even working out what design is a horn, T-TQWT etc.
Bjorno, however, seems to know them inside out and can do what would take me a month in hornresp in a few minutes! I was still playing with hornresp and he's already got a nice model back for you! Follow his advice-follow mine and it's like the blind leading the near-sighted
Bjorno, however, seems to know them inside out and can do what would take me a month in hornresp in a few minutes! I was still playing with hornresp and he's already got a nice model back for you! Follow his advice-follow mine and it's like the blind leading the near-sighted
Okay knowing what a T-TQWT speaker is now, and looking at the data Bjorno posted am I right if I say that I would need a T-TQWT speaker with a volume of 78 liters and a speaker length of around 80 cm's? But are those 80 cm's the total length, or are they where the speakers should be placed in the speaker and I would then need a total length of 120 cm's? And how do I go about placing two drivers in a T-TQWT configuration?
Hi Picarro, ready to be lead by the near sighted? I'm still learning this, so may be wrong-but if not we can learn together
Below is my interpretation of Bjorno's enclosure. For two drivers I would just double the internal height of 27cm to 54cm-but have to admit that's something I'm guessing at!
Hopefully what you're looking at below makes some sense to you and I'll try and explain how I came to these figures:
I took the values for the areas S1, S2, S3 and S4 from Bjorno's post. As area is LxH I needed to work out one of those figures 1st. Your sub diameter is 262mm, so I rounded this up to 270mm/27cm and made that the "height".
I then divided S1, S2, S3 and S4 by 27 to come up with the lengths of the sections for S1-S4 (as we can take 27cm to be the height) and then came up with the crude, not to scale, sketch below Fingers crossed I'm right!
Below is my interpretation of Bjorno's enclosure. For two drivers I would just double the internal height of 27cm to 54cm-but have to admit that's something I'm guessing at!
Hopefully what you're looking at below makes some sense to you and I'll try and explain how I came to these figures:
I took the values for the areas S1, S2, S3 and S4 from Bjorno's post. As area is LxH I needed to work out one of those figures 1st. Your sub diameter is 262mm, so I rounded this up to 270mm/27cm and made that the "height".
I then divided S1, S2, S3 and S4 by 27 to come up with the lengths of the sections for S1-S4 (as we can take 27cm to be the height) and then came up with the crude, not to scale, sketch below
Fingers crossed I'm right!Attachments
FYI, Here is a step by step approach to fold a T-TQWT like yours:
b
PS: TheBaronGroog 's layout is good too.
Attachments
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I am currently drawing the speaker in SketchUp but I am having some difficulty with the overall dimensions.
How long is the dividing wall, and at what angles should it meet the bottom piece?
Are the two thick green lines on the dividing wall the speaker units?
The hole opposite what I believe to be the speaker - what are the dimensions for that?
How do I calculate where the hole should be?
How long is the dividing wall, and at what angles should it meet the bottom piece?
Are the two thick green lines on the dividing wall the speaker units?
The hole opposite what I believe to be the speaker - what are the dimensions for that?
How do I calculate where the hole should be?
If you don't use angles and just use the lengths and areas you can do it all without a protractor.
The green markings are the speakers.
I don't know what Bjorno has used for the "frame width"-though the name would suggest the width of the frame of the driver-so 26.2cm though you could make this a little bigger-as I suggested in my sketch 27cm would give you some room to get in to screw down the drivers and would be easier to cut then 26.2cm
So the width for S's would be worked out by:
S1= 693/26.2
S2=621.8/26.2
S3=263.61/26.2
S4=231/26.2
S4 is the hole in front of the speakers, the figure 231 is it's area in SQ cm, it can be round, square or any other shape you wish (though square is the easiest and a uniform shape will have less chance of any vent induced noise)
The centre of the hole is 12cm (L34) away from the line marked S3.
The length of the internal baffle appears to be worked out by drawing a line 45degrees out from the corners, where they intersect the baffle ends.
Bjorno can correct me if I'm wrong!
The green markings are the speakers.
I don't know what Bjorno has used for the "frame width"-though the name would suggest the width of the frame of the driver-so 26.2cm though you could make this a little bigger-as I suggested in my sketch 27cm would give you some room to get in to screw down the drivers and would be easier to cut then 26.2cm
So the width for S's would be worked out by:
S1= 693/26.2
S2=621.8/26.2
S3=263.61/26.2
S4=231/26.2
S4 is the hole in front of the speakers, the figure 231 is it's area in SQ cm, it can be round, square or any other shape you wish (though square is the easiest and a uniform shape will have less chance of any vent induced noise)
The centre of the hole is 12cm (L34) away from the line marked S3.
The length of the internal baffle appears to be worked out by drawing a line 45degrees out from the corners, where they intersect the baffle ends.
Bjorno can correct me if I'm wrong!
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Ahh, it's the area covered - great! I can probably work it out now. I will most likely be posting a SketchUp drawing later.
What should I choose for an amplifier? This is a budget build so anything cheap and chinese from eBay will do.
Sorry for double posting, but the first sketch of the sub is done. The entire case is to scale and I even put in some grey filler material. I am unsure whether this needs to be in there but I believe so.
The only thing which I am still a bit unsure of is the placement of the drivers in relation to each other and in relation to the vent hole.
Edit: the wood used is 12 mm plywood.
The only thing which I am still a bit unsure of is the placement of the drivers in relation to each other and in relation to the vent hole.
Edit: the wood used is 12 mm plywood.
An externally hosted image should be here but it was not working when we last tested it.
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The sketchup looks great-however I'd look at using a thicker material-18mm would be better, you might also want to add some bracing to further reduce flex.
For an amp I'd look at a 2nd hand surround sound amp, capable of 250wrms+ at 4ohm, wire the speakers in parallel. Otherwise there are plenty of plate amps around that should play well into that. If you have hornresp enter in Bjorno's specs from above and produce an excursion graph and ensure you're not going to exceed X-max in the lowest octave-if so look for an amp with a suitable "subsonic"/"infrasonic" filter (either fixed high enough or better variable-so it can be used in other projects in the future) Technically you actually need a bandpass crossover (HPF and LPF) but most will describe that incorrectly as "subsonic"/"infrasonic"
For an amp I'd look at a 2nd hand surround sound amp, capable of 250wrms+ at 4ohm, wire the speakers in parallel. Otherwise there are plenty of plate amps around that should play well into that. If you have hornresp enter in Bjorno's specs from above and produce an excursion graph and ensure you're not going to exceed X-max in the lowest octave-if so look for an amp with a suitable "subsonic"/"infrasonic" filter (either fixed high enough or better variable-so it can be used in other projects in the future) Technically you actually need a bandpass crossover (HPF and LPF) but most will describe that incorrectly as "subsonic"/"infrasonic"
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