DIY - Sealed Subwoofer's (External powered)..

[elangoas]

Aweosme you finally build your own subs. What's the estimated f3 of this sub box combo?

Thank you.. Yup.. I don't know since i got the enclosure dimensions from ravindra..

Anyways have UMIK-1, will check them this weekend..

 

[saheb11123]

Congrats @elangoas you might be enjoying your sub a lot. What was the total cost for the sealed sub build?

 

[elangoas]

Congrats @elangoas you might be enjoying your sub a lot. What was the total cost for the sealed sub build?

Thank you @saheb11123 .. Approx 10K for drivers, 3K for enclosure material & build labour.. Totally 13K all inclusive..

 

[saheb11123]

3k for the materials that is cheap

 

[Naveenbnc]

Congrats Elangoas. Those L Champs are not necessary. You should have done internal bracing, its mandatory if the enclosure is sealed. The Sub is Giant, I think you should do internal bracing. Even a Square of 1 Inch x 1 Inch wood block will do. Just make a "+" inside the Enclosure.

Secondly i think you shoud increase the height of your feets, keep at least 2 inch distance between ground and Driver. (Just my suggestion)

I am also making Active Subwoofer Project but it's still Pending. (I am working on another plate amp, the one which i had made is taking a lot of space)

Hey Sadik, Im also waiting to see your sub. Once in a while I keep checking that thread

 

[elangoas]

3k for the materials that is cheap

Ok.. Yup.. Happy the way it has shaped up so far..

 

[iiirshad]

Thts very impressive

 

[elangoas]

What's the estimated f3 of this sub box combo?

Here is the room response of the subs.. Am not aware of how to check roll off (-3) of subwoofer from these graphs.. Rough guess is 20Hz.. correct me if am wrong..

 

[Naveenbnc]

Somewhere around 23hZ to 50hz the sub is doing a good and leniar job. After 50hZ the sudden raise and dips represents cone breakup or reaching Xmax. (If I'm right)

At around 23hz, the graph drops down at a steep angle. So that is the roll off point.

Draw a horizontal line covering the area of the graph that is mostly linear. (At around 93dB in this case)
Draw one more horizontal line, 3dB below the first line. The point (towards left side after roll off) where the graph touches the second line is the F3 point.

Jumping in between and telling my understanding so that experts can correct me as well
I'm just beginning to understand the graphs slowly.

 

[elangoas]

At around 23hz, the graph drops down at a steep angle. So that is the roll off point.

Draw a horizontal line covering the area of the graph that is mostly linear. (At around 93dB in this case)
Draw one more horizontal line, 3dB below the first line. The point (towards left side after roll off) where the graph touches the second line is the F3 point.

Jumping in between and telling my understanding so that experts can correct me as well
I'm just beginning to understand the graphs slowly.

Great @Naveenbnc

After 50hZ the sudden raise and dips represents cone breakup or reaching Xmax. (If I'm right)

I think nope.. It is due to room mode at that freq causing the spike and dips..

 

[Naveenbnc]

May be u r right, cone breakup won't happen at 50hz. And I suspect i made a bigger mistake. This is not the driver frequency graph. This is your room responce !!!??
Ignore my points elango, lets wait for experts

 

[elangoas]

May be u r right, cone breakup won't happen at 50hz. And I suspect i made a bigger mistake. This is not the driver frequency graph. This is your room responce !!!??

Np.. Yes.. This is my DIY sealed subs response in my room (listening position)..

Ignore my points elango, lets wait for experts

Itz ok.. You made an attempt.. Let the experts also chip in..

 

[danielnaveen2003]

Here is the room response of the subs.. Am not aware of how to check roll off (-3) of subwoofer from these graphs.. Rough guess is 20Hz.. correct me if am wrong..

I am guessing this is the inroom response with the sub on the floor? Or have you suspended them already? If possible can you measure a single sub outside? Some kind of balcony or portico. That will give a rough idea of how much of the bottom end is boosted by the room and how much is the actual output of the sub.

 

[elangoas]

I am guessing this is the inroom response with the sub on the floor? Or have you suspended them already?

Yes.. In room response of the subs, suspended from ceiling..

If possible can you measure a single sub outside? Some kind of balcony or portico. That will give a rough idea of how much of the bottom end is boosted by the room and how much is the actual output of the sub.

I can do that on the terrace, but don't have a laptop with HDMI output.. Need to get the PC and stuff to terrace.. Lil difficult..

 

[saheb11123]

Here is the room response of the subs.. Am not aware of how to check roll off (-3) of subwoofer from these graphs.. Rough guess is 20Hz.. correct me if am wrong..

The cone break up is at 100+hz it seems but the room has a dip at 60hz? A little dsp perhaps to smoothen out

 

[elangoas]

The cone break up is at 100+hz it seems but the room has a dip at 60hz? A little dsp perhaps to smoothen out

Thanks for the info.. Checking if there is possibility of flattening the response by dropping the subwoofer height and if it would minimise the peak & dips between 55Hz - 80Hz, i would then use a 80hz crossover to mains..

I think the peak at 60Hz & 70Hz are both due to height mode.. If the peak reduces after subwoofer height, then the dip also should reduce, though not very sure..

Here is the room mode chart of my room dimensions..

I have no experience with manual EQ.. AVR is with Audyssey XT32.. Have read that it can cut a peak by a maximum of 20 dB.. So peak at 60Hz should be minimised after Audyssey calibration.. But dip between 70 - 80Hz is huge..

The peak & dip look like almost inverse.. So thinking if adjusting the position (height of the sub) should get it smoother..

 

[saheb11123]

Yeah calibrate using audyssey and hope for the best. I would not tamper with eqs also they are just a big pain.

 

[elangoas]

Yeah calibrate using audyssey and hope for the best. I would not tamper with eqs also they are just a big pain.

There was some big improvement in the dip bet 60 - 80 hz, after dropping both the subwoofer height by 20 inches from its first position.. So am thinking to try a measurement with subs in differential heights and check if there could be any further improvement in the dip..

 

[diyaudio]

The scale is huge, it will hide problems, reduce to 30dB.

 

[elangoas]

The scale is huge, it will hide problems, reduce to 30dB.

Ok.. I took a snapshot of the default view with no smoothing.. If i set the limit to 20 - 80Hz, it should reduce the scale..