Problem with Adire PR need advice.. (1 Viewer)

[Robert_Sloan]

I finally finished my Adire Shiva/PR sub (EBS alignment) and I am having a problem with the PR. I used Avia and THX optimode disks to do LFE sweeps and around 35hz I believe the PR is resonating and going ballistic all the way out and all the way in and also from 28hz down to 20hz the PR sounds horrible. It makes a flopping noise. When I first built the sub I had a small air leak from one of the screws but I recaulked the screw and everything looks good. ALso just for good measure I put a seal of caulk on the outside of the driver and PR all the way around the outside of it and around the screws. The system is now airtight. I played 35 hours of music (24 hours at low level and 11 at a mid level) and Fight club, Saving Private Ryan, and Gladiator through the sub at medium levels to break it in.
I changed the mass of the PR by an additional 100 grams and that did not seem to change anything.
Should I build a new cabinet and scrap the PR or could something else be wrong?
Ideas?
I love the sound of the Shiva! I have a Velo HGS currently and decided the Shiva sounded like fun. I wouldn't say that they are identical by any means however since my Velo was in excess of 1200 and the Shiva was only 400 or so I would say it is a great sub.
I am getting ready to build 2 more Shiva's for end tables in my living room. I was going to do the vented EBs alignment for these.
Robert Sloan, CCIE
"Its not where you go... Its how fast you get there!"

 

[Julian Data]

Robert,
Something doesn't sound right as the EBS alignment is tuned to 17.3Hz. Once the PR alingnment reaches it's Fb, the PR itself reaches its maximum excursion depending on the power output. Prior to Fb the PR barely moves while the driver moves more in excursion. Of course, going below the Fb of the box both the active and passive units starts moving out greatly moves in and out.
If the PR is flapping around the 35hz area, something tells me that the your PR system is tuned pretty high. How much mass have you added? And how much power are you using?
From what you have posted it sounds like you have a high tune.
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[Greg Monfort]

You don't give details, but imply you've built the ~142L/17Hz alignment in the Shiva/PR apps paper. This requires that 252g be added to the PR's base 285g.
What you're describing is a too high tuned PR, and yet even just the base mass would tune it much lower than the ~35Hz indicates (~23Hz). Agreed there's no way it's leaking, or the PR would barely move, if at all.
OTOH, if you made a much smaller cab, then the base mass tuning would yield this type performance.
So what did you build? For sure don't give up on it!
GM
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Loud is beautiful, if it's clean

 

[TerryC]

Something is up, the dual PR Tempest sub I built PR's barely move until it's near tunning.
Did you add the mass? How did you do it/weigh it?

 

[Kyle Richardson]

It does sound like the tuning is too high as others have noted. Like they said, the PR should not move much until it nears its tuning point and then it should take over. I cannot remember the exact alignment you built but I may have sent you the list for a 85 liter alignment mass amounts.

If you are using the 142 liter EBS alignment try changing the mass to the 252g that Greg mentions. If it is the 95 liter SBB4 use 211 grams for a 22hz tuning point; if it is the 85 liter then use 395 grams for a 20Hz tuning.
If I sent you the wrong table for the mass amount then I am truly sorry. Once you get it tuned correctly you will notice a huge difference from the wrong tuning and it should perform to it's potential.
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[Robert_Sloan]

I want to thank everyone for their advice.
The PR was tuned too high as I used the wrong mass calculations for the PR. I corrected and tuned to the EBS alignment per Adire specs and this solved the problem. Now my Shiva is bottoming out around 25hz. I tested once again for air links and all was good. The slighest tap or push on the PR moves the shiva and vice versa.
I am curious if anyone else has had these issues. I am strongly considering building a ported cabinet instead of the PR to see if this is the issue. I have notced that the Shiva is bery loud although It does not seem to be as detailed as my Velo. The shiva is sending out a very thick stream of bass that gives it a muddy sound. I think this might be due to the alignment or the PR.
I am thinking to test my theory I will construct a pseudo 142.5L vented EBS box. I will insert a plug in teh hole where the PR resides and then put a sheet of MDF over this to gaurantee no air leaks. Then drop a port from the top of the box near the fron of the cabinet. I know this is not the exact alignment notes. However, I don't think it will cause to big of a difference.
Does anyone have any ideas why my Shiva would be bottoming out so high?
Does anyone see any problems with me modifying my current box this way?
Robert Sloan
Technology, only substitute for cubic inches...

 

[Julian Data]

Robert,
How much power are you using? How much mass did you add?
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[Robert_Sloan]

Kyle Richardson and I discovered the problem. The PR is apparently not functioning correctly. Just goes to show the level of service Kyle provides. Above and beyond every step of the way! I am waiting for another PR to arrive and when it does I will test it and also I will test a vented application to see how they stack up against each other.
I like the Shiva and I am going to get another one! I am going to build my end tables with Shiva's in the bottom of them!
Robert Sloan
Shaken, Not stirred

 

[Greg Monfort]

What's wrong with it?
TIA,
GM
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Loud is beautiful, if it's clean

 

[Julian Data]

Robert:
Was it the spider not returning properly? Or the cardboard tube misaligned???

Like Greg, what was it?
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[Kyle Richardson]

It seems that Robert isnt near his computer so I will answer for him It seems that the spider came detatched from the tube so even though he had the correct weight added, it was doing almost nothing allowing the Shiva to bottom out at very low levels.
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[Julian Data]

Ahh.. The glue for the spider.

That could cause some problems.

 

[Greg Monfort]

Sheesh DW, what kind of spiders are you raising that don't make strong glue?
GM
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Loud is beautiful, if it's clean

 

[Patrick Sun]

That's some weak-ass webbing, for sure!
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[DanWiggins]

Yes, Greg, you caught us... We switched to a different spider, the common daddy longlegs. However, the webbing isn't strong enough, so it's back to the Ecuadorian Birdcatcher for us.
Hardest part is milking the suckers, to get the silk...

For those not quite awake yet, this is a joke. It sounds like there was a problem with Robert's PR, having the spider separate from the tube. It may have been caused from a poor glue joint, or from repeated bottoming from the mistuning. But it's being replaced either way.
Dan Wiggins
Adire Audio
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[Jones_Rush]

...the Shiva is very loud although It does not seem to be as detailed as my Velo. The shiva is sending out a very thick stream of bass that gives it a muddy sound.

Anyone else care to comment about that ?

 

[Kyle Richardson]

Dan, you can milk anything with nipples --- Greg Focker from "Meet The Parents"

Of course it didnt sound good, it was basically a sub in a box that had no tuning since the spider was not connected to the tube. With that being the case there was hardly any resistance on the PR so it could move at will. I'm actually a little surprised he said it sounded as good as it did.
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[Greg Monfort]

JR,
I agree with KR, and once the PR's repaired I think RS will be singing a different tune.
GM
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Loud is beautiful, if it's clean

 

[Robert_Sloan]

Yes knowing the problem now I am sure the Shiva will sound great. I was disappointed to learn that they were out of stock. I have been a faithful Velo HGS person for a good while and now my HGS is for sale. I sealed my existing driver and played some music through it HOLY JEEPERS BATMAN! I honestly can't say that it beats the Velo but I could purchase 12 Shiva's for the cost of my Velo! The shiva is very good. The enclosure I have it in is wimpy and very temporary made in about 1 hour from scrap MDF out of my garage. It isn't even really a solid enclosure. No silicone or anything just glued together a buck of pieces to form a pseudo sub. I played som emusic through it and it went down to a note that I know is exactly 24.6HZ and it was pretty decent. THis was all done at approx. 80 watts and it was providing a good amount of bass without sounding like... well you know. I am hooked on the Shiva's. I watched the professional today (not for the sound but for the movie) It was very interesting. The Shiva kept right along and seemed very tight in gun fire and explosions. Even though it was sealed I was very impressed.
Dan, Kyle,
Thanks for replacing my PR. I examined the Shiva and it is built very solid. When you get more in stock scratch me down for one more.
Now I just have to try a Tempest!
Robert Sloan
Shaken, Not Stirred.

 

[John E Janowitz]

well, I don't normally jump into an Adire thread, but since the Shiva appears to be out of stock, you may want to look at the SAE1204 we sell. It will work very similarly to the Shiva in the same size enclosure. They are in stock and ready to ship. If you want more info, start another thread and I'll be glad to answer any questions.
John