Will I benefit from the subwoofer?

[mkusan]

Marko,

The response curves you posted in the last post does not resemble anything I have ever seen before, it has typographic errors in both the vertical and horizontal scales.

Art

Hello Art,
thank you for your input, lets wait for the proper measuring microphone then, too many unknowns this way.

I performed this test today from Elliott Sound Products webpage:

"Driver Selection
A quick word is warranted here, to allow you to determine if the speaker you have will actually work in a small sealed enclosure. The Linkwitz transform circuit (or EAS principle) will allow any driver to extend to 20 Hz or even lower. A good quick test is to stick the speaker in a box, and drive it to 50 or 100W or so at 20 Hz - you should see a lot of cone movement, a few things will rattle, but you shouldn't actually hear a tone. A "bad" speaker will generate 60 Hz (third harmonic) - if you don't hear anything, the speaker will work in an equalised sub.

If a tone is audible, or the speaker shows any signs of distress (such as the cone breaking up with appropriate awful noises), then the driver cannot be used in this manner. Either find a different driver, or use a vented enclosure."

And it passed without making a slightest noise

Regards
Marko

 

[weltersys]

I performed this test today from Elliott Sound Products webpage:

"The Linkwitz transform circuit (or EAS principle) will allow any driver to extend to 20 Hz or even lower. A good quick test is to stick the speaker in a box, and drive it to 50 or 100W or so at 20 Hz - you should see a lot of cone movement, a few things will rattle, but you shouldn't actually hear a tone.."

And it passed without making a slightest noise

Marco,

I don't understand how a speaker can be of any use at 20 Hz if you can't hear it, and it just rattles things. Evidently Elliott has difficulty hearing 20 Hz.
If the driver does not make any audible sound, yet is near Xmax ("a lot of cone movement") with 100 watts at 20 Hz, a LF EQ boost won't make it audible, other than if more power drives it into gross distortion, and you probably don't want that.

Art

 

[bentoronto]

Weird as it sounds, I use an OB sub-sub, mounted on a largish board under a table and irregular shaped. It plays little more than its resonance, which is about 21 Hz. My crossover flashes when there is power to this speaker so I know what of I am speaking here. I have lotsa bass recordings and can play the sub-sub all I want. But in average range of music, it plays very rarely... but I am delighted when it does and can feel the difference.

Also, a mic is perfectly clear that 20 Hz waves are floating around my room on bass (side) drums, whether audible or not,.

My own system aside, it is abusive to drive drivers with a super low Linkowitz transform (READ: good old tyme bass boost). Just asking for trouble and lots of Doppler distortion.

I like OB sound but, as Art (a man of considerable experience) points out makes little sense way down low.

Ben

 

[mkusan]

Hello all,
sorry it took me so long to respond but I realized it would be futile to continue
without proper measurement data. I built mic preamp with condenser microphone similar to mitey mike going to line in on my pc sound card. I hope this time measuring graphs will make more sense.

As for the Linkwitz transform circuit, I don't need my driver to extend to 20Hz, and if I understand you right that is not even possible with this specific driver.

I think I would be happy with flat response from 40 Hz, lowest bass note on guitar is 41 and I don't listen to organ pipes.

Anyways here are the results and I welcome your input.

Regards
Marko