Hello all !
My present project inspire me for an better one with a relatively high SPL from 20hz.
I sii pro audio drivers are more efficiency than hi-fi one. And i learn that lower end frequency are "monophonic" because in a normal room, the ear cannot make difference in position of a 30hz for exemple.
So, is it possible, with passive method, to combine the two channels subwoofer in a same "center bass" enclosure with two pro large diameter drivers ?
Is there something like a good idea around that ? I don't want active subwoofer.
I just want to take a 25 watt amplifier and ear all the spectrum. A speaker set with 20-3000khz at 95db 1w 1m.
I will get a big center and two normal sized floor-standing.
Because now my speaker are big and don't reach this spectrum at all. (55hz-20khz at 93.5db±1db)
Ideal and advice ?
Thanks
Edit :
I see car audio subwoofer have good SPL in low end.
My present project inspire me for an better one with a relatively high SPL from 20hz.
I sii pro audio drivers are more efficiency than hi-fi one. And i learn that lower end frequency are "monophonic" because in a normal room, the ear cannot make difference in position of a 30hz for exemple.
So, is it possible, with passive method, to combine the two channels subwoofer in a same "center bass" enclosure with two pro large diameter drivers ?
Is there something like a good idea around that ? I don't want active subwoofer.
I just want to take a 25 watt amplifier and ear all the spectrum. A speaker set with 20-3000khz at 95db 1w 1m.
I will get a big center and two normal sized floor-standing.
Because now my speaker are big and don't reach this spectrum at all. (55hz-20khz at 93.5db±1db)
Ideal and advice ?
Thanks
Edit :
I see car audio subwoofer have good SPL in low end.
Hoffman's iron law says that you cannot have a small enclosure with high sensitivity and deep bass. If you want 95dB @ 20Hz, you're going to need a 10-20 cubic foot (app. 290-580 litre) enclosure.
If you want high efficiency to 40 Hz, you need about 5 cubic feet for the bass driver. The mid and tweeter will need their own enclosure space, so you're talking about very large speakers.
Also, it's better to have 2 different locations of bass drivers, as it can lead to better modal behavior of bass within the room.
What speakers are you currently using?
If you want high efficiency to 40 Hz, you need about 5 cubic feet for the bass driver. The mid and tweeter will need their own enclosure space, so you're talking about very large speakers.
Also, it's better to have 2 different locations of bass drivers, as it can lead to better modal behavior of bass within the room.
What speakers are you currently using?
For the enclosure size, no problem.
I want to do an "center box" for subwoofer. Like passive subwoofer with 2 drives. It can measure up to 60" wide X 20" tall X 22" deep so about 15 ft³
I have Monitor Audio (tiny floorstanding 91db with 33hz response)
And i have an almost finished DIY boxes with 92-94db (no measure again but more efficient thant Monitor Audio in ear) Tuned to about 45hz but i havec some difficulty with bass extention. The bass is good only if i boost it on the "bass" button. I think i have a verry slow spl drop from 300hz to 50hz afteer what, the curve drop faster.
This speaker are big 9"W 16"D and 52"H (57 with base and spikes)
Now, i want to "cut" this speaker at about 43"H and tune it to ~50hz for recovering more constant SPL in mid bass and add a subwoofer inclosure.
The only way i can add volume here is by adding an "hidden" enclosure in the center of the room
I want to do an "center box" for subwoofer. Like passive subwoofer with 2 drives. It can measure up to 60" wide X 20" tall X 22" deep so about 15 ft³
I have Monitor Audio (tiny floorstanding 91db with 33hz response)
And i have an almost finished DIY boxes with 92-94db (no measure again but more efficient thant Monitor Audio in ear) Tuned to about 45hz but i havec some difficulty with bass extention. The bass is good only if i boost it on the "bass" button. I think i have a verry slow spl drop from 300hz to 50hz afteer what, the curve drop faster.
This speaker are big 9"W 16"D and 52"H (57 with base and spikes)
Now, i want to "cut" this speaker at about 43"H and tune it to ~50hz for recovering more constant SPL in mid bass and add a subwoofer inclosure.
The only way i can add volume here is by adding an "hidden" enclosure in the center of the room
Inductor said:
Yes, i used it but the small version. This is where i learn than i can't expect deep bass + high spl bass with my MTM configuration with a constant curve !
For your main driver and tweeter, i already have a floor-standing project.
I look for the JBL on WinISD.
... with two locations ... how can i do it ? Two 10-20'³ enclosure is simply too big ti fit in room
The only possibility is one subwoofer. If i cannot use the two channel bass output from the amp, i will need an active subwoofer.
Is it nothing i can do to add some bass in my 9x16x52 boxes with keeping my current SPL ? separate in two chamber and add a larger woofer on the side ?
The only possibility is one subwoofer. If i cannot use the two channel bass output from the amp, i will need an active subwoofer.
Is it nothing i can do to add some bass in my 9x16x52 boxes with keeping my current SPL ? separate in two chamber and add a larger woofer on the side ?
Another thing overlooked is the cost of the Passive components for a subwoofer...these can get very expensive!
Sorry but that is not a "BIG" speaker, as it means ( to my way of thinking ) that your bass/midrange driver is no larger that 7inches, as Inductor and Badman said you need the big box with big speakers.
But I do think that you should experiment with the centre sub idea, bearing in mind that it may not work.
Are these the external or internal dimensions?
Even if this is the external dimensions that is a largish volume, but a box like that will need to be made with thick material and lots of bracing so look to loosing about 20%, which you can make up by using good damping.
I do not think 2 * 12inch drivers will do it but 4 wired series /parallel should and use a good plate amp and use it where the mains are down 6dB
oaristys said:
You could try a 6th.order bandpass with big inductor
But inductor may easily cost the same as active plate subamp
Besides, 25watt wont work anyway
I currently have almost all of the bass i want with my DIY speakers. The problem is the amplitude drops about 1 to 3 db from 250 to 40hz.
My 30 watt amp have ha bass button from - 8 to 0 and 0 to +8. If i turn it to about +4, i have good bass.
Maybe i don't need 20hz but i think a hearable 30hz and strong 35hz will be fine.
I understand the physics law... but understand me, it's look like the wanted result is at few inch of me ! lol
If i can get this bass with button set to "0", it will by a victory except if i have to reduce all the non bass spectrum by few db.. It's the same tame
I think the inductor issue make me drop the 20hz goal. Forget it. If i want it, i will build a thor subwoofer or something like that. I don't think my 20-45hz need to be super hi-fi anyway.
Now i need to know if the enclosure volume above the bass reflex port is usefull. My brother said no. Example. If i place the port in the middle of the box and my woofer is obove, i halves my enclosure volume.
My 30 watt amp have ha bass button from - 8 to 0 and 0 to +8. If i turn it to about +4, i have good bass.
Maybe i don't need 20hz but i think a hearable 30hz and strong 35hz will be fine.
I understand the physics law... but understand me, it's look like the wanted result is at few inch of me ! lol
If i can get this bass with button set to "0", it will by a victory except if i have to reduce all the non bass spectrum by few db.. It's the same tame
I think the inductor issue make me drop the 20hz goal. Forget it. If i want it, i will build a thor subwoofer or something like that. I don't think my 20-45hz need to be super hi-fi anyway.
Now i need to know if the enclosure volume above the bass reflex port is usefull. My brother said no. Example. If i place the port in the middle of the box and my woofer is obove, i halves my enclosure volume.
Ok guys i think i found the solution for all spectrum with 110db/1w/1m. I can use a 6 watts amp.
http://www.royaldevice.com/custom.htm
Ho my God i think i'm scared about this room.
Lol what a horn !
http://www.royaldevice.com/custom.htm
Ho my God i think i'm scared about this room.
Lol what a horn !
Moondog55 said:
Some test with WinISD show me that one Selenium WPU1807-SLF 18" Driver mounted in vented 18ft³ tuned to 22hz can reach extend my Tb W6-789 MTM (93db) project to 20hz at -3db
But i have two problems.
1. Crossover the subwoofer will cut $$$$ inductor
2. How to converge the two channels to only one driver :s Any subwoofer amp have the crossover system but is that exist in passive mode ?
3. If i have only one subwoofer box but two loudspeakers L+R. I need 3db more efficiency in the subwoofer .. no ?
Thank's
oaristys said:
Simple. Forget the passive crossover. You can buy a decent plate amp for a sub for about $100 that does everything you need. Run R&L speaker wires to it and it will combine the signals to the sub. It has plenty of power to drive the sub without using any power from your main amps. It has a volume control and an adjustable crossover that you can dial in to get the best blend with your mains.
Here's one. There are many more to choose from.
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-804
An externally hosted image should be here but it was not working when we last tested it.
Or high-pass the speakers and use the line level input on the plate amp.
OP needs to do a lot of research though.
OP needs to do a lot of research though.
catapult said:
Hes, i think it's the best way for a home cinema but this project is linked to a high efficiency stereo project. So put more power to do the job is not a goal.
I can do smaller enclosure than mine with powerful amp and a deep bass with good drivers. But now, i search a solution work with my 35watt tube amp.
oaristys said:
Then you are going to need 2 subs. There is no way to mix the sound from both channels into a single voice coil without ruining the stereo of your main speakers.
catapult said:
A passive low-pass filter on each of the stereo outputs feeding into a transformer wound with an input for each channel and single output for the bass drivers will solve the summing problem and adjust for some sensitivity differences between main and sub enclosures.
Might be a good product to sell audiophiles so they can use stand-mounted monitors with excellent imaging, sub-woofers for low bass, and get the quality of their main amp instead of cheap silicon garbage...
Drew Eckhardt said:
Ho, i think you understand my need ! I a like your idea.
Is it possible to buy a transformer and modify like that :
http://web.telia.com/~u85920178/power/diy_transformers.htm
It will be a bit weird to used a 18" 1 200 W heavy duty professional subwoofer to play .... 30W lol. But anyway, it cost less than a 6" scanspeek woofer. 😉
Question : if i have a track with low frequency identical to two channels pass trough 35wpc amp, the "passive low pass transformer" will produce one signal of 70w ?
And with 70 watt, the sub will produce same level than two separate. But with big enclosure and apropriate and efficien driver, you got deeper bass ?
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