[nexxest]

Hello all,

So I sold my Polk junk and started building proper subs. Designed by LTD02.

My living room/HT is 3300 cuft. Subs are tuned to 17Hz. 30mm and 22mm MDF is used. Powered by iNuke 3000DSP. Driver: 1542D. One sub is done.

Plans:

MDF:

Bracing:

Adding primer:

 

[nexxest]

Painting:

Alpine is huge:

Nearly done:

Fun:

Done:

Find the sub:

 

[nexxest]

2 (or 4) will be built (depents on wife's mood). REW graphs coming soon.

 

[LTD02]

Bravo!

solid bracing, nice paint, really sneaks in behind the couch too.

 

[LitoGeorge]

Mmmm - that nearfield going to feel good!

 

[Jay1]

Very nice build

 

[pgwalsh]

Nice work. Looks great. I may have missed it, but where's the other one going?

 

[nexxest]

Thanks all!

Second sub will go behind the couch aswell. The width of the sub is 50 cm, and I have 2 meters of room there.

First graph, no EQ, no HPF:

 

[jpmst3]

Nice build! Congrats!

Also, mucho kudos to LTD02...yet again!

 

[ronny31]

Nice, I'm a big fan of the Alpine Type R subs. Works in tons of enclosure designs and have nice SQ. They can also take a bunch of juice due to effective cooling.

 

[LTD02]

despite looking around several times in the past, i have never been able to find a measurement of that driver. others have searched in vain as well.


next time you are set up to run some measurements, if you get the inclination to drag the sub into the middle of the room and place the mic about 3 inches directly in front of the driver and run a full sweep (at least up to 200hz) with no room correction, no eq, no low pass filtering...that would be pretty cool.

 

[ronny31]

despite looking around several times in the past, i have never been able to find a measurement of that driver. others have searched in vain as well.


next time you are set up to run some measurements, if you get the inclination to drag the sub into the middle of the room and place the mic about 3 inches directly in front of the driver and run a full sweep (at least up to 200hz) with no room correction, no eq, no low pass filtering...that would be pretty cool.

Do that outside at 1 meter perhaps more useful.
Its sensivity is terrible due to rock-solid mechanical resistance (you can rest another subwoofer on the cone without it bottoming out), but this means it has extremely low distortion. 1000w rms 3000w peak during music sounds exactly like 100w rms 300w peak only louder. Its probably the most common series of subwoofers in the car SQ scene here in northern Norway.

 

[LTD02]

thank you. i understand what you are saying. i am simply interested in the information requested while being minimally burdensome. a close mic response is all that i really am looking for.

 

[nexxest]

Just 3 inches? Nothing else? No port plugging?

 

[nexxest]

Btw, I could easily bottom out the Polk with one finger. With Alpine, you need two legs

 

[LTD02]

"Just 3 inches? Nothing else? No port plugging?"


with such a low tune, its all driver from about 30hz up* and that is what i am interested to see, so no port plugging is needed. just look'n for a simple raw sweep of the driver with no processing/filters/eq/etc.




*i meant from about 30hz up the response of the driver in the ported cab and the sealed cab are about the same. the port is actually providing some contribution everywhere and significant contribution below about 40hz.

 

[nexxest]

Plugging ports:

PS: mic was in MLP.

 

[nexxest]

One port plugged, HPF 12dB @ 16Hz, added some EQ:

 

[kappajoe]

Nice looking build... What Net (after bracing, etc) cuft. volume are you using for the 17hz tuning?

 

[nexxest]

170 liters or 6 cuft.

LTD02, what happens when I plug a port? Does it affect excursion or requirements on HPF?