Belva 1SV12B Sub Enclosure

[robert J]

Hi everyone,

I am thinking of buying this Belva 1SV12B 12" sub box and I have read conflicting specs on it.

Has anyone here bought one and if so, confirm specs and port area/cf? I am guessing on port specs here but it looks to be pretty good. I changed the external dimensions (1st calc pic) in order to get it to 1.8 net simulating any bracing inside to bring it to manu specified specs.

Cheers.

The box would be for the sub below and future subs.

Click to read more...

 

[THATpurpleKUSH 5,000+ posts]

Junk.

Don't waste your time and money. There are MUCH better options out there.

This is where you should be looking...and they ship to Canada

SoundSolutionsAudio's Online car audio store | We Finance! 60 second credit decision! Best prices, products and customer service. Fast shipping to US & Canada.

 

[BOOMINGRANDPA 5,000+ posts]

no they to small and port is horrible.. don't buy that.. only 2 prefabs that aren't to bad msw has a 2cf with ok port and low tune $149 (on ebay) mine is by boomboxtech on ebay he will make box to your specs.. what sub do u have?

 

[BOOMINGRANDPA 5,000+ posts]

https://www.ebay.com/itm/12-Inch-CUSTOM-PORTED-MDF-CAR-STEREO-SUB-WOOFER-ENCLOSURE-2-CU-FT-TUNED-32Hz/400334071716?_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%26asc%3D44040%26meid%3D1f43fcc7c6094cc5a14f36d47e5ee30a%26pid%3D100011%26rk%3D6%26rkt%3D12%26mehot%3Dpp%26sd%3D263275681541%26itm%3D400334071716&_trksid=p2047675.c100011.m1850 this is basically mine with longer lower tuned port and box is deeper. i even had him move sub cutout closer to port side of box with no carpet or terminals but with shipping they not cheap.. message him through auction tell him what size and tuning u want (tell him 2-4 hz below what u want to account for sub disp.) https://www.ebay.com/itm/STAGE-2-PORTED-SUBWOOFER-MDF-ENCLOSURE-FOR-AMERICAN-BASS-XR12-SUB-BOX/263177242969?hash=item3d46960959:g:keEAAOSwWflZ6V5G&vxp=mtr

 

[THATpurpleKUSH 5,000+ posts]

Dude stop recommending shitty ebay prefabs.

 

[robert J]

If I plug in the port specs from their dual 12" box [1.5"x12.5"] assuming they are the same, the box will be tuned to about 41Hz, not 36Hz.

Also, the net volume is 1.73cf with a port area/cf of 10.51/ci.

Do these numbers seem ok for the above Alpine 12? Alpine Spec sheet suggests 1.7cf tuned to 34Hz

UPDATE:

 

OK, thanks guys.

 

[robert J]

no they to small and port is horrible.. don't buy that..

Too small? Then you don't like this one either?

 

[BOOMINGRANDPA 5,000+ posts]

Dude stop recommending shitty ebay prefabs.

i assure u mine ain't bad.. did u even look at my double baffled box?, his 3/4 mdf is same as everyone elses..

 

[BOOMINGRANDPA 5,000+ posts]

If I plug in the port specs from their dual 12" box [1.5"x12.5"] assuming they are the same, the box will be tuned to about 41Hz, not 36Hz.
Also, the net volume is 1.73cf with a port area/cf of 10.51/ci.

Do these numbers seem ok for the above Alpine 12? Alpine Spec sheet suggests 1.7cf tuned to 34Hz

UPDATE:

 

OK, thanks guys.

if u listen to rap u want 36hz or under after sub disp.. if u only listen to rock 41 is probably ok

 

[THATpurpleKUSH 5,000+ posts]

i assure u mine ain't bad..

I assure you it is, you just don't what good is.

 

[robert J]

if u listen to rap u want 36hz or under after sub disp.. if u only listen to rock 41 is probably ok

I listen to lots of bass. I like to feel it, I like it punchy with low rumble.

I blew up a pic of the box and can see the port running along the back. So I calculate the port is 1.5"W x 12.125H x 18.25" approx. to get the 36Hz tune. If I extend the port to 24" I will achieve 34Hz with a the .08 vol sub. But my Vb goes down to 1.5cf

Port Area 18.19in/sq

10.89si/ft

Net box volume 1.67cf

With the 24" port:

Port Area is 12sq/in / ft

The tune and Vb are close to what Alpine suggests. What I don't know is if the port volume is ok?

Here is Alpine's Recommendation without and with batting

 

[BOOMINGRANDPA 5,000+ posts]

I assure you it is, you just don't what good is.

dude what do u think the diff is? also really more importantly what would u recommend someone to buy that don't cost $300? if peeps don't have a GOOD option they all end up with 45hz qbombs or atrends or the 1.3cf belva, 90% of people are not going to make their box

 

[BOOMINGRANDPA 5,000+ posts]

man port size is based on box size but depends on the sub and the power u are running too.. if u have like 500rms amp 12sq in per cf probably ok (because sub won't get that much after rise) if u running 700 or more u maybe pushing your luck with port that small., can't u make box/port bigger?

 

[robert J]

Dude, I posted the speaker specs sheet. 100Wrms. Amp capable of 300rms

So the port volume needs to rise as power rises and xMax rises. Is that to prevent compression? So, I am guessing 100W with these Alpines should be OK with a port area of 11 or 12sq/in. So, if I upgrade when I blow these speakers, this box won't be a good candidate for 4-600Wrms with 15-20mm xMax.

If the numbers work and the box is 3/4 MDF, I don't get why it is junk.

 

[BOOMINGRANDPA 5,000+ posts]

Dude, I posted the speaker specs sheet. 100Wrms. Amp capable of 300rms
So the port volume needs to rise as power rises and xMax rises. Is that to prevent compression? So, I am guessing 100W with these Alpines should be OK with a port area of 11 or 12sq/in. So, if I upgrade when I blow these speakers, this box won't be a good candidate for 4-600Wrms with 15-20mm xMax.

If the numbers work and the box is 3/4 MDF, I don't get why it is junk.

oh yeah if u have 300rms u fine.. yes more power u have more air movement, larger port keeps port air velocity down so it don't sound like a horn.. as far as sub with more power u need to model it in wins program to check port velocity but most subs in the 15-20mm xmax range will need bigger box anyway.. pioneer 3003 great option for that box with like 300-600rms, it works great in 1.63cf ported with same port u have and the recommend 1.5cf too..