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Discussion Starter #1
Greetings folks newbie here.

I had a converstion with Parts Express on telephone and by email and got 2 different answers regarding the Dayton 15" RSS390! I am looking at an old 340 liter sealed box that housed an Adire Tempest 15". I looked at the response on winsd which looked good for my situation (large room and sub will be used for pedal tones on the digital pipe organ--good at 32 Hz and acceptable at 16 Hz) with the room and boundary gain at 250 watts.
I double checked with PE and one fellow said go for it with their 1000 watt rack amp--the other wrote back on email saying it was meant for a 3 cu ft box and therefore "will NOT work at all"...
The guy installing tehdigital pipe organ said not to go with a ported sub.
Wisdom from you folks??
 

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Re: Dayton RSS390HF for Electric Pipe Organ PA

Asiquis,

moved your post to it's own thread to avoid distracting an existing project thread.

-Brent
 

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Did you specify which version of the RS390 you were asking about? The HO version does look pretty good in a 3 ft^3 sealed box, IMO. The HF wants at least 6 ft^3 sealed for a .7 or lower Q.

250 watts is already enough to exceed Xmax below 27hz with the 390-HF in 340l, so going with the 1000 watt amp would just be a waste of money.

Looking at the models, 340l (12 ft^3) doesn't gain you significant output over a 6 ft^3 box with the HF. Since you've alread got the cabinet, I'd consider dropping two drivers into it for nearly a full +6dB increase over the single, with the appropriate amp(s) per driver. You do realize the DVC15 is a drop in replacement for the Tempest and is a bit cheaper than the RS series.

I can't think of why a properly designed ported sub woudn't be suitable if the power handling and SPL requirements for playback are met. Of course, sustained sub 30hz pedal notes really make me question a single driver's suitability for a church? environment. What does the organ manufacturer normally recommend for playback? Surely they offer a total system solution.

-Brent
 

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Discussion Starter #4
Thank you for moving my post--whoops:nono:!

The local guru wants to sell us a Definitive Technology subwoofer a supercube 1
We do not have the cash
We had been using a Paradigm PDR-12 which gave half decent base for the 16 ft pipe (32 Hz) in this venue.
We corner loaded it and it was not so boomy. It has been taken back by the owner (it was on loan)

The local guru stated that ported subs "sound bad" with the pipe organ that's why he wants to sell the DT sub-- since it has passive radiator design.

I had the idea of a 15" sealed, but maybe I will have to go ported.

I was looking for minimum of 3db down at 32 and 10-12db down at 16 hz which would work out well with some room gain and boundary gain (looking for about 96 db at 2 meters). I plugged in the Dayton RSS390HF-4 15" Reference HF Subwoofer in a 340 litre sealed and got the besel alignment
(.56) and the -3db at 32 and -9db at 16.35 and the 96db SPL we need.........at 250 watts. I do not have a way of checking the Xmax issues?
Any wisdom would be appreciated.
PS this building is a frame circa 1870 building that needs no amplification for speaking--its built like an instument itself and is very lively, which is what one wants for pipe organ music, which is contrary to home theatre and such. Originally they had of course a foot pumped organ that was actually quite loud in there!! must have been some folded horn "under the hood" :dunno:

Ray
 

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First, you might want to find a different "local guru". A passiver radiator is still a bass reflex alignment. The PR performs the same function as a port.

WinISD Pro Alpha and Unibox both calculate cone excursion at a given frequency using user specified input power.

For your project, I think you should look at the SPL numbers more than the f3 point. WinISD and Unibox model 1m groundplane (no room gain) SPL by default. WinISD allows you to adjust the distance, not sure about Unibox. Even with the default 1m, you'd just subtract 6dB for a 2m sim.

Sealed box output is about driver displacement. The RS series are excellent sound quality drivers based on user reviews and objective measurements. However, they are a little short in the Xmax department. For your application, especially with that existing box, I'd strongly consider the Tempest-X with double the Xmax of the RS390 and only slightly more expensive.

Here's the 390HF (red) and Tempest-X in sealed 12 ft^3 (yellow) at 1m with 250 watts...and a Tempest-X in 11 ft^3 tuned to 16hz (green), also 250 watts. I dropped the box to 11ft since the port will consume some additional volume. At 20hz, it's almost like having two sealed boxes. Bump the ported box to 500 watts (it'll take it) and you'll have a 7dB advantage at 20hz.
 

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