is tuning at 25Hz too high?

[Matt Neilson]

WINISD tells me that in order to tune to 22Hz with my 88.5 litre box shiva and 4 inch port(non-flared), it will need to be 0.487m long, problem is the max port length i can achieve is 0.33m which means tuning at abou 25.7Hz, is this too high for HT and music?

[Magura]

Most albums are not really going under 50Hz, so 25 is fine.

Magura

[officeboy]

I think it might be a bit of a problem, At 40Hz, your +2 db and it might get boomy.

You can of course add some elbows to make your port longer, or build a slot port into one of the walls of your box.

Also you have read this right?
http://www.adireaudio.com/Files/Vent...plications.PDF

[Matt Neilson]

yes i have read that, the problem is that i built a sealed alignment box and want to make it ported now

[richie00boy]

Make the vent longer with 90 degree elbow joint. The unloading won't be a problem as there isn't much energy below 25 Hz, but the vent noise might be high with the Shiva's massive excursion.

Build without elbow first, but leave room for the elbow to be added if you find the vent noise too much. If you don't add any EQ to the low end then you will probably not run into a vent noise problem.

[Paradise_Ice]

Originally posted by officeboy
I think it might be a bit of a problem, At 40Hz, your +2 db and it might get boomy.

You can of course add some elbows to make your port longer, or build a slot port into one of the walls of your box.

Also you have read this right?
http://www.adireaudio.com/Files/Vent...plications.PDF

There all right in there advice, an elbow or a right angle bend in your port would be the way to go, ATC do it, so dont think its a poor mans trick, This is less energy in music below 50hz, that is true, but its nice to be able to get down there on the few tracks that can,

[mikee12345]

on my music-drum n bass and hiphop
50hz is common
40hz occasionally
36hz and below rare occasions,usually for short durations

so low tunings are only useful for HT

my jbl was tuned to 33hz,it covers music quite nicely with an overdamped response too.

You could extend the port outside of the box too,but the end correction factor will be different

[Artmaster]

25Hz - not enough, couse "E" string of bass gitar -sub-sub contr octave has freq about 11 Hz.

[officeboy]

Originally posted by Matt Neilson
yes i have read that, the problem is that i built a sealed alignment box and want to make it ported now

The reason I ask if you have read the VentedShivaApplications.pdf is because for an 85L box, they recommend a 3" wide by 8.375" long vent. For a tuning of 20Hz (it’s the Adire alignment)

[qi]

IMO an "ideal" system would go to 15HZ (including room gain)

For further details see this thread...

Horn vs Open baffle bass