F15 to FV15HP for 80% music 20% movies. Good idea?

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Originally Posted by curtis

This is absolutely true, and well documented.

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Thanks Curtis.

That said, I've read that you'd actually need more like 3-5 sealed subs to match the output of an equivalent ported sub. However, I will not be listening or watching movies at reference levels - I tend to keep the volume knob a few notches lower than my brother does, for example, if that makes a difference in which sub I should consider. My room is about 350 sq. ft.

Is the 14 Hz vs. 18 Hz extension noticeable in movies on the F15HP vs. FV15HP? I'd likely leave both ports open if I get the FV to minimize chuffing, since I certainly want to avoid that.

Is the benefit of two subs vs. one in terms of nondirectionality significant even if I will be using Audyssey MultEQ XT32 for room correction? (I realize this is likely a subjective question.) Although there's something appealing about two subs, I'd obviously rather save the money if I can, lol :).

Thanks guys - any opinions from people with experience are much appreciated.

3-5 subs to equal a ported? Where are you reading that? That may only be true at the tuning point of the port on a ported sub...even then I am not quite sure.

Your room seems large...you mentioned the square footage, what about the cubic footage? height x width x length....that is the total area the subwoofer had to move air in.

Port noise is at the extreme...I don't think it will be something you have to worry about. As the the difference in 14hz and 18hz, I doubt you would hear the difference in movies. Sealed vs ported for music....I bet you would hear the difference.

Audessey could possibly help even room response, but not anything like having more than one subwoofer.

I currently use a F15HP in a approximately 2150 cubic ft room with no issues. I would like to use another to even out room response, but don't really have a good place to put it.

Quote:

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Originally Posted by curtis

3-5 subs to equal a ported? Where are you reading that? That may only be true at the tuning point of the port on a ported sub...even then I am not quite sure.

Your room seems large...you mentioned the square footage, what about the cubic footage? height x width x length....that is the total area the subwoofer had to move air in.

Port noise is at the extreme...I don't think it will be something you have to worry about. As the the difference in 14hz and 18hz, I doubt you would hear the difference in movies. Sealed vs ported for music....I bet you would hear the difference.

Audessey could possibly help even room response, but not anything like having more than one subwoofer.

I currently use a F15HP in a approximately 2150 cubic ft room with no issues. I would like to use another to even out room response, but don't really have a good place to put it.

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My room is about 320 (or slightly bigger) sq. ft. with most of the area having a 7'9" ceiling and a smaller area having a 6'11" ceiling. So, probably around 2400 cubic feet - similar to you, maybe a bit bigger. I'm currently drafting up a floor plan to see if I can accommodate two subs :).

I heard that two subs provide a more even response, but that the ported will still have a higher output (which again, is not my primary concern as long as it's more than capable enough for my listening levels). You may be right that the 3-5x is at the tuning point for the ported sub while at higher levels, the difference is much less.

Hey guys,

Is anyone able to provide information similar to the below (in a comment from an SVS article) in comparing the F15HP and the FV15HP? I can't seem to find detailed measurements on either Ascend or Rythmik's sites. I'm also interested in seeing a group delay curve, but can't seem to find one of those either.

Thanks!

Ed Mullen Mod Rich • 2 months ago
Hi Richard -

Room gain will actually affect a ported sub and a sealed sub equally - both for FR and for enhancing max output. The primary difference is that a sealed sub will simply have a better chance at a flat in-room response to ULFs due to its shallower roll-off slope.

Since a ported sub rolls-off at a much steeper slope (typically 36 dB/octave with a 2nd order HPF), it will never have any chance at a flat in-room FR to ULFs, since the maximum theoretical amount of room gain is 12 dB/octave and in the real world is more like 7-9 dB/octave.

With respect to maximum output capability, the PB-2000 and the SB-2000 (single sub vs. single sub) stack-up as follows - and again this delta will remain constant in-rooom since room gain will equally augment both subs:

PB-2000 has 1.5X more maximum output at 40 Hz.
PB-2000 has 2X more maximum output at 32 Hz.
PB-2000 has 3.5X more maximum output at 25 Hz.
PB-2000 has 4X more maximum output at 20 Hz.
PB-2000 has 2.5X more maximum output at 16 Hz.

From there it's simple math - the largest max output delta occurs at 20 Hz, where you would need eight (8) SB-2000 to match the maximum output capability of your current dual PB-2000. Naturally at any of the other frequencies stated above, eight (8) SB-2000s would outgun dual PB-2000 by the ratios stated above.

To answer your specific question, if you are primarily concerned with the 16-32 Hz octave, four (4) SB-2000 will equal dual PB-2000 at 32 Hz, and will fall short by varying degrees in the 16-25 Hz bandwidth.

Ed M.

Ahh...I see where you are coming from now.

I really don't think you need to worry about maximum output abilities in your room.

Your best bet is to contact Brian Ding of Rythmik.

Got it, thanks Curtis.

I agree, I probably don't have to worry. Just want to make sure I have all the information before making a decision, since I'll likely be living with it for the next 10 years or so! :)

I have one E15HP and honestly I think its more than enough for movies, thought I'd for sure want two but really happy with just one... moving this thing from BC to Calgary made me grateful I only had one to move

Interesting - thanks for your thoughts, brah (lol).

As an aside, I know this is not ideal, but if I were to allow the subwoofers to double as end tables (one on each side of my couch), is there a recommended finish? Piano black seems like it would be easier to clean, but I've been told that in a home theater setup, you want to avoid shiny surfaces like the plague since if anything happens to reflect off of them (even a dimmed light at the side of the room or a cell phone LED), it will be very annoying. Does anyone have their take on the pros/cons of the different finishes, or the practicality of using subs as end tables, lol?

Piano black is also much easier to scratch. For some he gloss is not bothersome, for others is it. It really depends on the room and lighting angles, as well as preference/tolerance.

Lots of folks use subs as end tables, but IMO, the F15 is a little small for that type of use.

If you are looking for the optimum setup, be aware, the best placement for the subs in terms of performance, is usually not the most aesthetic.

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Originally Posted by TyCanadian

With respect to maximum output capability, the PB-2000 and the SB-2000 (single sub vs. single sub) stack-up as follows - and again this delta will remain constant in-rooom since room gain will equally augment both subs:

PB-2000 has 1.5X more maximum output at 40 Hz.
PB-2000 has 2X more maximum output at 32 Hz.
PB-2000 has 3.5X more maximum output at 25 Hz.
PB-2000 has 4X more maximum output at 20 Hz.
PB-2000 has 2.5X more maximum output at 16 Hz.

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Rythmik's 20hz output is published as:

At 20 Hz, our subs vary in their maximum output capability. The output at 20 Hz is shown relative to F12.

F12: 0db (baseline)
F15: +2db
D15: +2db
LV12R: +2.5db
E15HP: + 3.5db
F15HP: +4db
FV15: +7db
FV15HP: +9.5db
F25: +8db

I can't find the source at the moment, but someone from Rythmik said that, at bass frequencies, it takes around 5dB for a perceived doubling of volume.