16-46pci Question

**hallb76** · **04-18-08, 06:58 PM**

Hi, I'm looking at an svs 16-46pci subwoofer for 50% music and 50% home theater in an 10x11x8 room with no openings. I currently have an hsu stf-2 that is great for music but not so great for home theater. I am looking for a sub with extension to ~15hz and more output that performs as well as the stf-2 with music. Any opinions on how the 16-46 would compare to the stf-2 would be greatly appreciated. I am open to any other suggestions in the $600 - $800 range.

**mike c** · **04-18-08, 07:12 PM**

with that small of a sealed room, i don't think you need the 16-46 ... the PB12NSD should be cheaper and give you 15hz in room extension no problem.

**hallb76** · **04-18-08, 07:32 PM**

Thanks for the reply! How do the svs subs compare to the stf-2 in terms of music performance? If they perfom equally as well with music I don't mind paying an extra $50 for more output.

**mike c** · **04-18-08, 07:56 PM**

i've never heard the HSU subs. but:

Quote:

STF-2 At a Glance
Amplifier Power 200 Watts
Bass extension +/- 2 dB 25 Hz
Woofer size 10 Inches

its tuned high and has a 10" woofer. you certainly wouldnt be getting flat to 15hz with the STF-2.

maybe with the VTF2.3 you could.

**Ed Mullen** · **04-19-08, 06:12 AM**

The 20-39 PCi custom tuned to 17 Hz (no charge) is also a nice option if you want a deeper playing cylinder without the added height of the 16-46 PCi.

This subwoofer has a somewhat overdamped response which will be a good match for the acoustic transfer function (i.e., room gain profile) of your small room.

While the PB12-NSD (also tuned to 17 Hz) would be a good choice, it's a big box and floor space is a premium in a 10x11 room. The cylinders are lighter, easier to move, and take-up much less floor space than their box counterparts.

**hallb76** · **04-19-08, 07:47 AM**

Ed, thank you for the input. Could you give me a relative output comparison (max spl) between the 16-46 and the 25-31 with custom tune in the 15-25hz range. I'm not sure if this matters but I don't corner load my sub. I prefer the sound with the sub placed 2-3ft directly behind my listening position about .5-1ft from the wall. The corner produces too much boom.

Will either of these subs outperform the stf-2 in terms of max spl across the spectrum from 15-80hz?

**Ed Mullen** · **04-19-08, 08:24 AM**

Quote:

hallb76 wrote:

Ed, thank you for the input. Could you give me a relative output comparison (max spl) between the 16-46 and the 25-31 with custom tune in the 15-25hz range. I'm not sure if this matters but I don't corner load my sub. I prefer the sound with the sub placed 2-3ft directly behind my listening position about .5-1ft from the wall. The corner produces too much boom.

Will either of these subs outperform the stf-2 in terms of max spl across the spectrum from 15-80hz?

The 16-46 PCi has about 7 dB more maximum clean output at 16 Hz than the stock 20-39 PCi. The "17-39" PCi splits the difference, gaining about 3-4 dB over the 20-39 PCi.

All three subs are in a virtual dead heat at 20 Hz.

From 25-80 Hz, the 20-39 PCi leads the pack, followed by the 17-39 PCi, and the 16-46 PCi. They are all pretty close though - the biggest differential occurs at 40/50 Hz, where the 20-39 posts a 2 dB advantge over the 16-46. All other test frequencies are within 1-1.5 dB for all three.

The STF-2 has comparable output as all three PCi models from 63-80 Hz. At/below 50 Hz, the PCi starts to assert an advantage, which grows quite large at/below 40 Hz. This is not a knock against the STF-2 (which is a good subwoofer), but the STF-2 does have a much smaller enclosure volume, a 10" woofer, and a 3" port tuned to 25 Hz, and therefore should not expected to perform as well as the PCi line at the deeper test frequencies.

**hallb76** · **04-19-08, 03:55 PM**

That is exactly what I needed to know. I've got one more sub to check out but the 16-46 sounds like a winner. With any luck the 16-46 will perform musically and I'll be able to pawn off my hsu. Thanks again Ed, your input is greatly appreciated.

**Ed Mullen** · **04-19-08, 05:00 PM**

Quote:

hallb76 wrote:

That is exactly what I needed to know. I've got one more sub to check out but the 16-46 sounds like a winner. With any luck the 16-46 will perform musically and I'll be able to pawn off my hsu. Thanks again Ed, your input is greatly appreciated.

No sweat.

I still think the 17-39 PCi is a better choice in a 10x11 room since you will have a lot of room gain and the subwoofer will exhibit a rising in-room response. To the exent you can mitigate that with an overdamped response, you should.

**hallb76** · **04-19-08, 06:36 PM**

Ed, I'm familiar with room gain but what do you mean by overdamped?

I will be getting a BFD soon to tame some room modes. Would that make any difference in selecting a particular model?

**Ed Mullen** · **04-19-08, 07:12 PM**

The 16-46 PCi has a critically damped response, meaning it's flat to system tuning (as measured quasi-anechoic). The 17-39 PCi has a slightly overdamped response, meaning it will exhibit a mild roll-off before system tuning. In a small room, the 17-39 PCi will have a more accurate frequency response than the 16-46 PCi.

Of course any excessive gain can be scrubbed off with a variable slope/frequency high pass filter or shelving filter, if your Behringer has those features. Check out the DCX 2496 and the DEQ 2496 for example.

**hallb76** · **04-19-08, 10:06 PM**

I see what your saying now. I was a little hesitant to bank on a certain amount of room gain then I realized you happen to know a great deal more about these things than I do so I think I'll take your advice. Paying additional money for output I'll have to filter out doesn't make alot of sense.

Three more questions that hopefuly won't bring more questions.

Are room modes and room gain one in the same?

Is room gain partly a function of wall construction (density, thickness, insulation..)? I ask because I live in a manufactured home with fairly thin walls

Do you know how the 17-39 stacks up against the Rythmik DS15 in terms of output below 20hz?

**hallb76** · **04-22-08, 07:17 PM**

I pulled the trigger on a B-stock 20-39 pc+. I know it's overkill but I think it's future proof and I like the additional tuning options. I also believe having too much is better than not enough. I'm hoping this will be the last sub I have to purchase for a few years.

A big thanks to everyone who helped me especially Ed, who patiently answered all my questions.

**OvalNut** · **04-22-08, 07:33 PM**

Good choice. You'll love it.

In your room, plug one port and set the subsonic filter switch to 16hz. You'll be golden!

Please let us know your impressions.

Tim

**Ed Mullen** · **04-22-08, 07:55 PM**

Quote:

hallb76 wrote:

I see what your saying now. I was a little hesitant to bank on a certain amount of room gain then I realized you happen to know a great deal more about these things than I do so I think I'll take your advice. Paying additional money for output I'll have to filter out doesn't make alot of sense.

Three more questions that hopefuly won't bring more questions.

Are room modes and room gain one in the same?

Is room gain partly a function of wall construction (density, thickness, insulation..)? I ask because I live in a manufactured home with fairly thin walls

Do you know how the 17-39 stacks up against the Rythmik DS15 in terms of output below 20hz?

We appreciate the business.

Regarding your questions:

Room modes and room gain are not the same thing. A room mode occurs when the 1/2 wavelength is shorter than the longest dim in the room and the room supports a modal response (where peaks and nulls can occur from standing waves).

Below a certain frequency (based on room size), the room will no longer support a modal response because the 1/2 wavelength is longer than the longest room dim. At that point the room transitions to a pressure response. The theoretical acoustic transfer function is +12 dB/octave for a monopole source in a perfectly rigid and sealed vessel. Of course real rooms have lossy boundaries and open floor plans which conspire against attaining the theoretical maximum amount of room gain, and most room exhibit something along the lines of 6-9 dB/octave, although it can/does approach 12 dB/octave at the deepest frequencies in small enclosed rooms with rigid boundaries.

Filtering the reponse to attain a flat (i.e., accurate) in-room FR is not wasting the subwoofer's inherent output capability; you are actually increasing available headroom and reducing the potential for subwoofer overload by letting the room do the work for you. Room gain is your friend/ally - just make sure the final in-room FR is flat to the corner frequency of the subwoofer and you'll have great sound and lots of clean headroom.

**hallb76** · **04-24-08, 06:13 PM**

The sub should arrive Monday which is also my girlfriend’s birthday. That should be interesting. I'm hoping I can meet the birthday requirements this weekend.

Tim, I'll definitely let you guys know what I think. It will be nice to tell someone who is actually interested in these things instead of trying to explain it to my girlfriend who really doesn't care. I told some of my students about the sub today and they didn't seem overly interested either.

Ed, thanks for the lesson.

**hallb76** · **04-28-08, 10:01 PM**

The 20-39 arrived today and I've had a couple hours to play with it. The first thing I noticed was that it plays low frequencies extremely loud in my room. I ended up plugging 2 ports for the 12hz tune and it's still playing flat from 25-12hz at about 85-90db. I haven't turned it up any louder but right now it isn't breaking a sweat. My room sweep shows I need to tame a peak from 30hz down to 12hz and a peak from 50 to 67hz. I haven't experimented with sub placement but I really like it behind me and I don't want to move the 5ft 20" tube traps from the front corners of my room.

The sub is amazing for movies, I heard things in transformers that I never heard with the hsu. I didn't hear anything extra in fight club but, the bass was much smoother and detailed.

The sub blends well allowing more detail and clarity from my mains and my front stage seems to have opened up a great deal. The svs doesn't have that punch the hsu has but I'm going to reserve judgment until my BFD arrives on Friday. Changing the tune to 12hz and using the PEQ on the amp to smooth the 60hz peak a little did wonders so I'm sure the BFD will do more.

Over all I'm very pleased to this point and I don't think I'll have any problems parting with the hsu.

Thanks again to everyone who helped, who knows what I would have ended up with without your guidance.

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