shiva with pr 15 please help!!!

[hassandaman83]

hi guys and gals!

i need help! i am a total novice with diy audio but i'm pretty handy at wood work!

i am considering building a shiva (mk3 or 4) with a pr15 passive radiator, with the 142.5L enclosure on the adire website (http://www.adireaudio.com/Files/PRApplications.PDF).
it has the flatest and widest in-room response, i'm not really sure what that really means!

but basically i want a really good all rounder, but music is slightly more important than HT. i would like it to go down to about 25hz or lower if possible.

so which of the adire shiva designs should i go for, IT CAN BE ANY DESIGN ON ADIRE'S WEBSITE considering my room is only 5m by 2.7m and 2.2m high, but space for the sub isnt an issue. And I HATE PORT NOISE so i would like to stay away from ported designs but if there isnt any port noise i would definately consider it!

i will be very greatfull for any feed back, thanks!!!!!!!!!

[keyser]

generally you should go with a bigger box if space is not an issue. using a passive radiator eliminates port noise. Calculating your own allignment can be difficult. Even if you have formali and computer software, you will see that every program suggests a different allignment. I suggest you build one of the boxes Adire suggests, then you can't really go wrong.

[hassandaman83]

hey thanx for your reply!!

Great! i now know that the designs are okay for what kind of sound i want!

i just need to know 1 little thing, my room is only 5m by 2.7m and 2.2m high.

is it too small for a large sub? because i've been told that the size of a room can effect bass response. room gain??

i'm very greatfull for yur reply!

[simon5]

If your room is small, you're just gonna get higher SPL, a more powerful sub that will sound louder.

[keyser]

simon is right. there's no problem as having too much power. one problem with small rooms is that standing waves are more easily generated. It can be harder to find the right place and settings for the subwoofer. in my experience this problem becomes less significant when the speakers and subwoofer become better. I don't know why this is...
the sub you are planning to build seems a very good one to me. You will get serious output! I would go for that one.
If you keep the internal volume the same, you could change the shape if the box to your likings without changing the sound. just make sure not to get too strange dimensions with one side being the tenth of an other.

[morbo]

I would go ported rather than passive radiator for music if you can... best of all IMO would be sealed. Have a look at this:

http://www.adireaudio.com/Files/Tech...GroupDelay.pdf

whitepaper to explain the differences in group delay between the 3 alignments.

[keyser]

Hey!
i never knew that about group-delay. I thought Reflex and Passive Radiator were kind of identical in response!
well, then i neither see a reason to go with a more expensive PR allignment.
just make sure the port gets not to small in diameter. thin ports may cause so-called chuffing-noise if a lot of air moves through. from about 3.5" you should be okay

[simon5]

And use flared ports if you can.