Low end extension with RSS390-HF in 3.0cu ft

[jeffknob]

I have two RSS390-HF 15" subwoofers. I was thinking of putting them each in their own PE 3.0cu ft sealed enclosure. I would be using an external amp, not a plate amp. In room what sort of low end extension can I expect to get? Am I right in thinking that room gain would help boost the low end some?

I have a BFD so if it naturally doesn't go too low, could I boost the low end a little with the BFD?

Thanks

[dougg]

> I have two RSS390-HF 15" subwoofers. I
> was thinking of putting them each in their
> own PE 3.0cu ft sealed enclosure. I would be
> using an external amp, not a plate amp. In
> room what sort of low end extension can I
> expect to get? Am I right in thinking that
> room gain would help boost the low end some?

> I have a BFD so if it naturally doesn't go
> too low, could I boost the low end a little
> with the BFD?

> Thanks

I run a RSS390-HF 15" in 2.3cf sealed (1.5" thick MDF walls). I use the 500w plate amp and boost the low end with the eq. I run a 20hrz tone to it and the entire house shacks!

These RS subs are amazing.

[jeffknob]

> I have two RSS390-HF 15" subwoofers. I
> was thinking of putting them each in their
> own PE 3.0cu ft sealed enclosure. I would be
> using an external amp, not a plate amp. In
> room what sort of low end extension can I
> expect to get? Am I right in thinking that
> room gain would help boost the low end some?

> I have a BFD so if it naturally doesn't go
> too low, could I boost the low end a little
> with the BFD?

> Thanks

I guess there aren't too many people that have the RSS390HF.

[philiparcario]

Provided Link: pic of dayton rss390hf-4


> I guess there aren't too many people that
> have the RSS390HF.
I have a rss390hf in a 3.25 box. there is a huge thread on it around nov to dec. you can get 23hz in a sealed 3.25 box with a filter designed by daryl on this website. I have a link with my build and a picture of his filter . his filter is a np cap of 2500uf and a 1 ohm 100 watt resistor this changes the sub in a sealed box . it lets it go to 23hz in a 3.2 cu ft box

[jeffknob]

> I have a rss390hf in a 3.25 box. there is a
> huge thread on it around nov to dec. you can
> get 23hz in a sealed 3.25 box with a filter
> designed by daryl on this website. I have a
> link with my build and a picture of his
> filter . his filter is a np cap of 2500uf
> and a 1 ohm 100 watt resistor this changes
> the sub in a sealed box . it lets it go to
> 23hz in a 3.2 cu ft box

I tried to find some more information on this. Did I read right that efficiency is lost because the resistance is increased to 6ohms and therefore more power is needed to reach the full potential? If I were to order the parts from PE, what would I need to get?

[philiparcario]

> I tried to find some more information on
> this. Did I read right that efficiency is
> lost because the resistance is increased to
> 6ohms and therefore more power is needed to
> reach the full potential? If I were to order
> the parts from PE, what would I need to get?
what happens is re is changed from 4 to 5 ohms this changes qts which lets you put the driver in the 3.25 box and get the f3 of 23 or 24hz instead of 30hz in a 5 ft box. the resistor does that part . is also make a little bit of a boom in the sub not good. the cap at 2500uf is a high pass filter. it will let 13hz and up play which flatens out the little bit of a boom. so what you get is a sub that plays down to 23 or 24 hz . whats lost is some volume and bass under 13hz. the filter can be removed to see what you like better. you need 4 of part 017-4 4ohm 20w resistor at 70 cents each 2.80 dollars total and 5 of 027-378 500uf non polarized cap 6.90 each total of 34.50 plus the 2.80 is 37.30. email me at <A HREF="mailtohiliparcario@yahoo.com">philiparcario@yahoo.com</A> I will send a diagram

[jeffknob]

> what happens is re is changed from 4 to 5
> ohms this changes qts which lets you put the
> driver in the 3.25 box and get the f3 of 23
> or 24hz instead of 30hz in a 5 ft box. the
> resistor does that part . is also make a
> little bit of a boom in the sub not good.
> the cap at 2500uf is a high pass filter. it
> will let 13hz and up play which flatens out
> the little bit of a boom. so what you get is
> a sub that plays down to 23 or 24 hz . whats
> lost is some volume and bass under 13hz. the
> filter can be removed to see what you like
> better. you need 4 of part 017-4 4ohm 20w
> resistor at 70 cents each 2.80 dollars total
> and 5 of 027-378 500uf non polarized cap
> 6.90 each total of 34.50 plus the 2.80 is
> 37.30. email me at <A HREF="mailtohiliparcario@yahoo.com">philiparcario@yahoo.com</A>
> I will send a diagram

I sent you an email. To model this arrangement in WinISD, which parameters would I need to modify and what would I change them to?

Thanks!

[dougg]

> what happens is re is changed from 4 to 5
> ohms this changes qts which lets you put the
> driver in the 3.25 box and get the f3 of 23
> or 24hz instead of 30hz in a 5 ft box. the
> resistor does that part . is also make a
> little bit of a boom in the sub not good.
> the cap at 2500uf is a high pass filter. it
> will let 13hz and up play which flatens out
> the little bit of a boom. so what you get is
> a sub that plays down to 23 or 24 hz . whats
> lost is some volume and bass under 13hz. the
> filter can be removed to see what you like
> better. you need 4 of part 017-4 4ohm 20w
> resistor at 70 cents each 2.80 dollars total
> and 5 of 027-378 500uf non polarized cap
> 6.90 each total of 34.50 plus the 2.80 is
> 37.30. email me at <A HREF="mailtohiliparcario@yahoo.com">philiparcario@yahoo.com</A>
> I will send a diagram

How about you save the $37 (and the lost power) an just use the BFD to boost the low end?

[nepaeric]

Do yourself a favor, and do not follow the PE recommendation of 2.9 cubic feet, or you might become sadly disappointed, as I was. Instead, build it in a 4.25 cu ft enclosure, as my brother and I modeled it for. I am almost finished building mine, now, and put an Eminence Eclipse 12" in the 2.9 cu ft cabinet. I was thinking of also putting the Quatro in it, which would not have been a bad choice, when it was on sale in December, but I got a decent price from Madisound on the Eminence, re-cut a 1" MDF, 12" hole baffle, glued and screwed it over the old baffle with the 15" hole, and cut a hole for the SA-240 amp. Works great for the cost. Build the box 4.25 cubic foot and you'll find happiness, in my opinion.

Best Regards,
Eric

> I have two RSS390-HF 15" subwoofers. I
> was thinking of putting them each in their
> own PE 3.0cu ft sealed enclosure. I would be
> using an external amp, not a plate amp. In
> room what sort of low end extension can I
> expect to get? Am I right in thinking that
> room gain would help boost the low end some?

> I have a BFD so if it naturally doesn't go
> too low, could I boost the low end a little
> with the BFD?

> Thanks

[jeffknob]

> How about you save the $37 (and the lost
> power) an just use the BFD to boost the low
> end?

I would actually prefer doing that if possible. I don't know if the filter does the exact same thing as the BFD can do.

[jeffknob]

> Do yourself a favor, and do not follow the
> PE recommendation of 2.9 cubic feet, or you
> might become sadly disappointed, as I was.
> Instead, build it in a 4.25 cu ft enclosure,
> as my brother and I modeled it for. I am
> almost finished building mine, now, and put
> an Eminence Eclipse 12" in the 2.9 cu
> ft cabinet. I was thinking of also putting
> the Quatro in it, which would not have been
> a bad choice, when it was on sale in
> December, but I got a decent price from
> Madisound on the Eminence, re-cut a 1"
> MDF, 12" hole baffle, glued and screwed
> it over the old baffle with the 15"
> hole, and cut a hole for the SA-240 amp.
> Works great for the cost. Build the box 4.25
> cubic foot and you'll find happiness, in my
> opinion.

> Best Regards,
> Eric

I have two of the drivers so unfortunately I don't have the room for two 4.25cu ft boxes. I just ordered PE's 3.0 cu ft boxes because I also don't have the free time to build my own box. I will either use the filter or my BFD to fix the sound, or I might do both.

Thanks for the suggestion though.

[dougg]

> I would actually prefer doing that if
> possible. I don't know if the filter does
> the exact same thing as the BFD can do.

It is not the same excat thing, but the BFD will give you more flex ability you can tune it to YOUR room. I use the EQ on the plate amp and even in a very small 2.3cf sealed, the RS15HF performs very well. If I turn off the EQ the small cabinet is very evident.

Every now and then my two year old 'plays' with the knobs on the plate amp. I never know what to expect when I turn it on.. ;-)

Doug

[nepaeric]

I understand that box building isn't for everyone, and if you already ordered boxes, I'm sure you'll want to work with those.

Unfortunately, I really think the smaller box might not allow the driver to perform up to it's potential. At least, that was my experience with the RSS390HF. I modeled it around a 4.25 cu ft box, and rather than go with my calculations, and original design plans, followed the advice of a PE technical guy, and a misprinted PE catalog. (honest mistakes) Anyway, there were some remedial steps I took, which made a world of difference.

Perhaps you might wish to consider an alternative, which originally worked for me in the 2.9 cu ft enclosure, when I first experienced the bad sound and poor bass performance.- An aperiodic, restictive vent, and an exceptionally large amount of fiberglass damping.

This aperiodic vent could be anything from a "Variovent," or a homemade restrictive vent as in a port of a bass reflex design, but with a small quantity of stuffing of a slight compression, to allow the box to "breathe," somewhat. This will increase the "effective" box volume, giving the driver a "percieved" larger enclosure volume. An aperiodic vent could very well make your single driver suddenly perform as if there were two drivers.

Mine consisted of a 1-1/2" hole, and about 1/10th of an ounce of Mahogany Sound Acoustastuf, which is superior to ordinary Dacron polyester fiberfil pillow stuffing, and has 16 bends per inch. Although regular Dacron would suffice.

Another suggestion, if you are adamant in planning to use such a small cabinet, would be to stuff the hell out of it with fiberglas. 3-4 lbs, lining all 6 walls, as I did. This also helped tremendously.

The performance of the driver will be primarily based on how you set it up and use it. Give the driver and enclosure every possible opportunity to perform the way you expect it to.

For a vented alignment, you will want an even larger box, so that wouldn't work with your boxes. If happiness is a small, 3.0 cu ft box, these simple procedures will surely yield you a much better result, as they did mine.

Best Wishes,
Eric

> I have two of the drivers so unfortunately I
> don't have the room for two 4.25cu ft boxes.
> I just ordered PE's 3.0 cu ft boxes because
> I also don't have the free time to build my
> own box. I will either use the filter or my
> BFD to fix the sound, or I might do both.

> Thanks for the suggestion though.

[philiparcario]

> I understand that box building isn't for
> everyone, and if you already ordered boxes,
> I'm sure you'll want to work with those.

> Unfortunately, I really think the smaller
> box might not allow the driver to perform up
> to it's potential. At least, that was my
> experience with the RSS390HF. I modeled it
> around a 4.25 cu ft box, and rather than go
> with my calculations, and original design
> plans, followed the advice of a PE technical
> guy, and a misprinted PE catalog. (honest
> mistakes) Anyway, there were some remedial
> steps I took, which made a world of
> difference.

> Perhaps you might wish to consider an
> alternative, which originally worked for me
> in the 2.9 cu ft enclosure, when I first
> experienced the bad sound and poor bass
> performance.- An aperiodic, restictive vent,
> and an exceptionally large amount of
> fiberglass damping.

> This aperiodic vent could be anything from a
> "Variovent," or a homemade
> restrictive vent as in a port of a bass
> reflex design, but with a small quantity of
> stuffing of a slight compression, to allow
> the box to "breathe," somewhat.
> This will increase the "effective"
> box volume, giving the driver a
> "percieved" larger enclosure
> volume. An aperiodic vent could very well
> make your single driver suddenly perform as
> if there were two drivers.

> Mine consisted of a 1-1/2" hole, and
> about 1/10th of an ounce of Mahogany Sound
> Acoustastuf, which is superior to ordinary
> Dacron polyester fiberfil pillow stuffing,
> and has 16 bends per inch. Although regular
> Dacron would suffice.

> Another suggestion, if you are adamant in
> planning to use such a small cabinet, would
> be to stuff the hell out of it with
> fiberglas. 3-4 lbs, lining all 6 walls, as I
> did. This also helped tremendously.

> The performance of the driver will be
> primarily based on how you set it up and use
> it. Give the driver and enclosure every
> possible opportunity to perform the way you
> expect it to.

> For a vented alignment, you will want an
> even larger box, so that wouldn't work with
> your boxes. If happiness is a small, 3.0 cu
> ft box, these simple procedures will surely
> yield you a much better result, as they did
> mine.

> Best Wishes,
> Eric
Hey you could build the couch box I did and leave both ends open. I got so lucky it sounds great and It is a design that I have never heard of of seen. I have an open ended rectangle stuffed with fiberglass. 2 feet by 4 feet by 10 inches. the open ends are 2 feet by 10 inches and it sounds great. The caps from the filter keep it from bottom out issues.