About pro drivers in hi-fi for 20-20khz project

[oaristys]

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.

[badman]

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?

[Inductor]

Hi,
you can look for the JBL GT5 for bass maybe in a (do you know how to use WinISD?) 4th order bandpass, and a Fostex (FF225-K) as main driver and also one Fostex as a tweeter/supertweeter or a ribbon. After you choose where to go, post your idea.

[oaristys]

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

[oaristys]

Originally posted by Inductor
Hi,
you can look for the JBL GT5 for bass maybe in a (do you know how to use WinISD?) 4th order bandpass, and a Fostex (FF225-K) as main driver and also one Fostex as a tweeter/supertweeter or a ribbon. After you choose were to go, post your idea.

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.

[Inductor]

badman had a good advice 4 ya. You are on your own.

[oaristys]

... 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 ?

[mayhem13]

Another thing overlooked is the cost of the Passive components for a subwoofer...these can get very expensive!

[Moondog55]

This speaker are big 9"W 16"D and 52"H (57 with base and spikes)

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.

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

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

[tinitus]

Originally posted by oaristys
Hello all !

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.

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