Hi!
I'm finally continuing a project I started last year using an amp 6 from 41Hz
I have 4 monacor SPH-30X/4 (fullrange 3inch drivers) which i plan to put in a box approximately 7liters, 13*20*29 cm. I don't really have a choice in using this box because i'm doing it for a friend, and it has some sentimental value for him etc.
I've used box calculators / recommendations of box size and basically if i use a closed box it's suggested to use ~0.5liters. So my first question is really is this just proportional to the number of drivers i'm using, 4 drivers would be ~2li?
Obviously then my box is far too big. I don't really understand if this is dangerous for the drivers (mechanically) or it will just sound less than perfect?
That got me thinking that if i have to use this box it may be best to go ported/bass reflex? i'm getting rough calculations of about 1liter per driver for this approach. Again is that proportional, so for 4 i would just say ~4li?
Still i am pretty far from 7liters and i need to think about what size and how many ports i would use? If i have 4 drivers can i have just one port or do i need multiple? How to determine the size for this etc.
Thanks for you help, i've tried my best to get as far as i can myself but am reaching the limits of my understanding, if someone wants to point me to some reading material for all of this that would be most appreciated too.
Hope this is the right forum for this type of q
Ku
I'm finally continuing a project I started last year using an amp 6 from 41Hz
I have 4 monacor SPH-30X/4 (fullrange 3inch drivers) which i plan to put in a box approximately 7liters, 13*20*29 cm. I don't really have a choice in using this box because i'm doing it for a friend, and it has some sentimental value for him etc.
I've used box calculators / recommendations of box size and basically if i use a closed box it's suggested to use ~0.5liters. So my first question is really is this just proportional to the number of drivers i'm using, 4 drivers would be ~2li?
Obviously then my box is far too big. I don't really understand if this is dangerous for the drivers (mechanically) or it will just sound less than perfect?
That got me thinking that if i have to use this box it may be best to go ported/bass reflex? i'm getting rough calculations of about 1liter per driver for this approach. Again is that proportional, so for 4 i would just say ~4li?
Still i am pretty far from 7liters and i need to think about what size and how many ports i would use? If i have 4 drivers can i have just one port or do i need multiple? How to determine the size for this etc.
Thanks for you help, i've tried my best to get as far as i can myself but am reaching the limits of my understanding, if someone wants to point me to some reading material for all of this that would be most appreciated too.
Hope this is the right forum for this type of q
Ku
you can lessen the volume with something like polystyrene , tennis balls and whatever ,to find the right volume . Are you going to put all the drivers in the cabinet ? Do you connect all the drivers in serial-parallel ?
Hi,
Didn't think of that, i can just fill it up with polystyrene to reduce the total volume? Thats Awesome. Is having an excessively large box actually dangerous for the drivers mechanically or is it a question of sound quality?
Yes i am using all 4 in the box, in parallel (two on each channel gets me down to 2 Ohms which this amp can cope).
Using a ported design allows me to use a bigger box but i have read elsewhere it might not be advisable to try this unless i have some ability to test (i don't) and some experience (i'm newb).
Thanks for the quick reply!
Didn't think of that, i can just fill it up with polystyrene to reduce the total volume? Thats Awesome. Is having an excessively large box actually dangerous for the drivers mechanically or is it a question of sound quality?
Yes i am using all 4 in the box, in parallel (two on each channel gets me down to 2 Ohms which this amp can cope).
Using a ported design allows me to use a bigger box but i have read elsewhere it might not be advisable to try this unless i have some ability to test (i don't) and some experience (i'm newb).
Thanks for the quick reply!
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No dividing panel between them ? They share the same volume (=acoustic load) ,though they are little and there won't be lethal interference among them.
By putting some damping material on the inside , the speaker 'sees' a bigger volume ,around 20 % ,but you don't want it . But it's good to put some , to reduce the returning backwave...energy...
No there is no dividing panel between anything. SO you are saying i could put some e.g. polystyrene blocks in to reduce volume then put damping around this now smaller internal volume ?
DO you think it would improve things to use a ported dedisgn? If so help with calculating port(s) etc would be appreciated.
Ku
DO you think it would improve things to use a ported dedisgn? If so help with calculating port(s) etc would be appreciated.
Ku
Improve things ....I just don't know . Can you post a sketch of how are those drivers positioned on the baffle -or cabinet ?
I just can't understand what's the purpose of putting L & R channels in the same box . But if it fits you ( your friend )...
Maybe a dividing panel would help to improve ( I don't think so ) ...
So ,yes , a tube or a slot ,better in the back of the cabinet
But I can't calculate it 🙁
Good luck !!!🙂
I just can't understand what's the purpose of putting L & R channels in the same box . But if it fits you ( your friend )...
Maybe a dividing panel would help to improve ( I don't think so ) ...
So ,yes , a tube or a slot ,better in the back of the cabinet
But I can't calculate it 🙁
Good luck !!!🙂
Thanks for all your replied dude.
Essentially this a box that belonged to his grandfather (a musician in the US army) so he decided to turn it into something which would keep the theme. Having L&R is irrelevant for our purposes here, sound will be mono. But i am not an expert, I've just managed to get a hold of an amp-6 and it fit the purpose so i thought i'd use it.
Ku
Essentially this a box that belonged to his grandfather (a musician in the US army) so he decided to turn it into something which would keep the theme. Having L&R is irrelevant for our purposes here, sound will be mono. But i am not an expert, I've just managed to get a hold of an amp-6 and it fit the purpose so i thought i'd use it.
Ku
mmmh mmh - I see
There's something strange in you statement
So ,the first thing that you may do is to check if the box is 'tight' ,which means that it has no holes . Then ,after the speakers are in place and tightened ,you can hear the sound of true Acoustic Suspension / sealed box .
🙂
There's something strange in you statement
when you say that it's going to be Mono !!
So ,the first thing that you may do is to check if the box is 'tight' ,which means that it has no holes . Then ,after the speakers are in place and tightened ,you can hear the sound of true Acoustic Suspension / sealed box .
🙂
Heh you are observant 🙂.. Amp6 is stereo amp and can't be bridged to mono in a simple way. What i'm actually doing is mixing signals to produce mono(ish) sound. I may as well just not bother and let L+R mix in the air of the box....but i don't need to worry about that now..some discussion on the 41hz forums about this if your interested 🙂.
Box is tight, has no holes. I guess i will try a closed setup first, i just wanted advice about port calculations etc and whether it'd be worth it, once i make that hole i better get it right!!!!. Thanks for your interest though,
Ku
Box is tight, has no holes. I guess i will try a closed setup first, i just wanted advice about port calculations etc and whether it'd be worth it, once i make that hole i better get it right!!!!. Thanks for your interest though,
Ku
You're welcome !
I did a big mono box two month ago ,it was a 5 " in Double Chamber reflex (asymmetric ) plus a cheap PC speaker , free air .
The intent was to make each channel of a stereo amplifier to drive each unit ,but I failed to make an easy IC based electronic crossover ,so I went the 'passive' way ( it was for a friend ,bunch of ...).
The cheap PC speaker came after I blew a dome tweeter😎 too much distortion from the amplifier -I like to test at full power 🙄
So ,in the end it sounded great ...it was mobile ,powered by a car battery.
That is to say ...you could use the 2 amplifiers ,if you have the right drivers
and some coils and caps around ....😉
I did a big mono box two month ago ,it was a 5 " in Double Chamber reflex (asymmetric ) plus a cheap PC speaker , free air .
The intent was to make each channel of a stereo amplifier to drive each unit ,but I failed to make an easy IC based electronic crossover ,so I went the 'passive' way ( it was for a friend ,bunch of ...
).The cheap PC speaker came after I blew a dome tweeter😎 too much distortion from the amplifier -I like to test at full power 🙄
So ,in the end it sounded great ...it was mobile ,powered by a car battery.
That is to say ...you could use the 2 amplifiers ,if you have the right drivers
and some coils and caps around ....😉
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