Acoustic Visions 85 litre Passive Radiator kit (1 Viewer)

[Nick V]

I am considering buying the sub in question. I was wondering how it would compare to say an SVS 20-39 pci (that's the biggest damn sub I would ever consider buying). I much prefer the configuration of this sub compared to the HUGE SVS' but, if the sub is inferior I may still go with an SVS.

Also, this sub comes with the 12" Adire Shiva driver, I was wondering if this is the best driver to go with, I saw someone else on this forum that built pretty much the same sub, but used a 12" Dayton DVC instead. I was wondering if there would be any benefit to using a different driver, or if it's just a matter of taste??

 

[Nick V]

BTW, a link for this sub can be found Link Removed. It is the first sub from the top on the page.

 

[Dustin B]

The guy to talk to around here would be Jack Gilvey (he's really gotten into PR sub design recently). The Shiva and Dayton are almost identical, except the Datyon can match a Shiva's performance in a slightly smaller box. The thing is everything in that kit from Kyle is from Adire. You start mixing and matching from Adire and Parts Express and things get more expensive for Kyle to get. Parts Express also doesn't have any passive radiators that I'm aware of.

You can tune that box anywhere from 14hz, up to, well stupid high values (just remember the lower you tune the heavier the PR gets and the more likely it will start to rock the box). Adire recommends 20hz for that box size. Anywhere between 18hz and 22hz should do fine. With 250W it should be very close to a SVS 20-39PCi or CS. If you can't live with the SVS tube (which will have a smaller foot print, it will just be taller) this would be a excellent equivalent cost alternative.

Also remember than the Adire Dharman is $599 and only 20L larger than what you are considering.

 

[Rob Lloyd]

That's the exact sub I have - 85L Shiva/PR but with a PE 250w amp on back. I really like it. It's very musical and great w/ HT. Mine is tuned to 19hz.

I also have an SVS 25-31PCi and I don't like it compared to the 85L Shiva. I know you mentioned the 20-39 so that will hit the lower notes the 25-31 can't but comparing sizes the 85L is a no brainer for me.

I built an identical one for a friend who's very into music and plays drums and he loves it.

 

[Martice]

I can vouch for the performance of Rob's sub. I've had a chance to audition his and it's really quick and powerful. I think it packs more upper range punch and volume then my 214L Tempest sub but it obviously doesn't go lower.

If I had to go with anything other then my sub it would be the 85L sub because it's deeper then my 70L DVC 12" based sub and slightly punchier then my 214L sub.

I don't see how you could go wrong with the 85L.

 

[Nick V]

Good to hear Rob,
I've had a very good feeling about the sub from the first time I saw it on the acoustic visions web page.
BTW, what are the dimensions of your sub?? I'm trying to get a good guage of how big it is.

 

[Dustin B]

Nick, I'd imagine its' dimensions would be identical to the 85L Adire Allignment outlined in this PDF file.
http://www.adireaudio.com/Files/PRApplications.PDF

 

[Kyle Richardson]

Yes, Robs sub is built to the Adire .pdf link that Dustin pointed out. That does not mean that we can't do other shapes though.

 

[Tom Vodhanel]

I seriously doubt an 85L/single 12"pr/12" shiva/dayton/250w combo is going to approach the dharman or any of the 20-39 models at svs in clean output capabilities

 

[Dustin B]

The PR is Adire's PR15. 824cm^2 Sd and 31mm one way Xmax for over 5L of Vp and can be weighted up to 1500grams. You think it won't suffice down low with a Shiva Tom?

 

[Tom Vodhanel]

Have Kyle build the little 85L box, measure its THD and response groundplaning and then have him clone a dharman and do the same. This would eliminate any question,


TV

 

[Rob Lloyd]

Yes it's built to the same outside dimensions as the Adire PDF listed. I changed it to forward firing though. I was trying to keep it lower to the ground to make it as small as possible.

Rob

 

[Kyle Richardson]

Right, this uses the 15" PR which is fine for a single Shiva and performs on par with a ported sub of the same size/components. Of course a Dharman will put out a bit more SPL since it is a larger cab and is tuned higher, but it isnt a night and day difference.

 

[Rob Lloyd]

I'm building a Dharman for someone this/next week so I'll let you know how they compare. Might be tough in my small 12x15 room but I think I can get an idea of how it will compare to the smaller sized PR sub.

 

[Dustin B]

Rob, you got an spl meter?

You could download the 30 day spectraplus trial and do the measurements Tom has requested outside for us (about as close as you'll get to anechoic).

 

[Kyle Richardson]

Yes, he has both...this could be fun. Too bad I'm out of town all of next week when he'll finish up the Dharman clone (same basic volume with the same components, just a different shape) and will be able to do some quick tests. Oh well, I'll find out the results when I return.

 

[Rob Lloyd]

I'll see what I can do. I have Spectra and EFT trials but I haven't played with them much yet. If you have any quick pointers that would be very helpful.

 

[Tom Vodhanel]

It's all in the THD...and I'm not here to claim the lower THD will always be preferred either.Remember,all things being equal...the higher the THD, the more raw SPL a simple meter is going to register. If anyone is going to try THD measurements with the RS meter as the mic...I would definitely drag everything outside. Try to get as far away as possible from the nearest reflective boundary(at least 60ft ideally). This makes things much more repeatable IMO.And if things aren't repeatable...then you are wasting your time. In fact, I would also suggest running a full day of GP tests...and then repeating them a few days later to verify results(within a reasonable tolerance)before making many posts on the internet about them. If you had a Melissa or Full Clio setup...in room checks would be a little more presentable.

TV

 

[Dustin B]

I've never played with the programs yet. I will eventually when I have the fundstime (really too bad I don't have the funds right now as I do have the time) to experiment on my own.

But I'm sure Tom will give you any pointers you need on taking the measurements as he would be just as curious as us to see the results.

 

[Rob Lloyd]

Well I don't have a few days to test or 60ft of clear space to do it in. With the house, garage and fences I can get about 25-30ft of clear area.

So this will be an un-scientific, non-repeatable test. So take it for what it's worth. Non-repeatable because I have to ship the Dharman sub to it's owner. I also have to see if he minds me doing this to his new baby.

Sounds like the pressure is on! It might not be until after next week as the Shiva hasn't shipped yet.

So there you have it. A possible test in the works with the worst conditions I can come up with:
- No ballfields to try it in
- New Shiva vs a year old Shiva
- No break-in on the new one
- No full day testing
- No repeat testing
- No high tech gear - Just a laptop and a RS meter.
- Software I'm not sure how to use

With all that, do you guys still want me to test it?