New Home Theatre - Need a Sub

[shadyJ]

Re: the FV15HP vs the XV15, I'll see if I can make it simple:

Subwoofer	PSA XV15	Rythmik FV15HP
	#'s from PSA Website	#'s from DB, Native Tune
CEA 2010 - 16Hz	98.1dB (from DB)	102.1dB
20Hz-32Hz Avg	116.6dB	122.5dB
40-63Hz Avg	125.1dB	128.1dB
20-63Hz Avg	121.8dB	125.8dB
Output Ratio	1	1.6

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Cheers

The problem with that chart is that averaging out the frequencies like that hides the XV15's peakish response. The FV15HP manages a far more linear response when pushed, so a more complete frequency response comparison paints an even worse picture for the XV15. Moreover the FV15HP manages a passing 12 Hz measurement which is not something the XV15 could achieve. Also keep in mind the FV15HP's much lower distortion and compression measurements for the same output sweeps. On top of all that, the numbers from Tom's site should be considered bogus as they have been improperly inflated to compensate for its orientation in measurement. Tom's own orientation measurements which I linked to illustrate this. Quite honestly it is a stretch to call the XV15's performance even half of that of the FV15HP.

 

[fuzz092888]

The problem with that chart is that averaging out the frequencies like that hides the XV15's peakish response. The FV15HP manages a far more linear response when pushed, so a more complete frequency response comparison paints an even worse picture for the XV15. Moreover the FV15HP manages a passing 12 Hz measurement which is not something the XV15 could achieve. Also keep in mind the FV15HP's much lower distortion and compression measurements for the same output sweeps. On top of all that, the numbers from Tom's site should be considered bogus as they have been improperly inflated to compensate for its orientation in measurement. Tom's own orientation measurements which I linked to illustrate this. Quite honestly it is a stretch to call the XV15's performance even half of that of the FV15HP.

Unless I'm missing something or made a mistake I altered Steve's chart with numbers from DB for both subs. There is a large performance gap, but not one that should be unexpected when comparing an $800 sub to a $1300 sub IMHO.

Subwoofer	PSA XV15	Rythmik FV15HP
	#'s from DB Website	#'s from DB, Native Tune
CEA 2010 - 16Hz	98.1dB (from DB)	102.1dB
20Hz-32Hz Avg	106.2dB	122.5dB
40-63Hz Avg	115dB	128.1dB
20-63Hz Avg	110.6dB	125.8dB
Output Ratio

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[Steve81]

Unless I'm missing something or made a mistake I altered Steve's chart with numbers from DB for both subs. There is a large performance gap, but not one that should be unexpected when comparing an $800 sub to a $1300 sub IMHO.

Subwoofer	PSA XV15	Rythmik FV15HP
	#'s from DB Website	#'s from DB, Native Tune
CEA 2010 - 16Hz	98.1dB (from DB)	102.1dB
20Hz-32Hz Avg	106.2dB	122.5dB
40-63Hz Avg	115dB	128.1dB
20-63Hz Avg	110.6dB	125.8dB
Output Ratio

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You'd still need to add 9dB to the PSA's numbers (except 16Hz) as I normalized the Rythmik's to 1m peak values (which is what PSA reports on their site). Looks like you might just be doing simple averages in dB as well, but I'm too lazy to check

 

[fuzz092888]

You'd still need to add 9dB to the PSA's numbers (except 16Hz) as I normalized the Rythmik's to 1m peak values (which is what PSA reports on their site). Looks like you might just be doing simple averages in dB as well, but I'm too lazy to check

I notice now that you normalized, glancing at the Rythmik's numbers on DB. Oh well.

 

[wldock]

Thanks all for the great feedback and recs....lots of things for me to look into and review. A couple other quick questions...

1. Is there a frequency "sweet spot" range that most subs operate in that I should be considering when looking at test data or should I just be looking at the sub with the best low frequency performance?
2. Of the subs mentioned so far which have the best sound management tools/features? Since my recevier does not have SubEq options is this something I should also be considering for on board options or are there other tools to help with this?
3. Given my B&W speakers and their rated range is there a sub listed that matches better with them?

1. For home theater LFE you are basically looking for good Low Frequency Extension and output to about 115 dB if ou want to bring the house down.
2. I think several have a parametric EQ, DSP control, etc. However, for more detailed room correction an outboard system (Like MiniDSP, Behringer feedback destroyer, REW, AntiMode, SMS-1, etc)might be needed.
3. Bottom line, you need a sub if you are going to belt out the low end effects. Its not so much a sub mating up better with your speakers as it is getting the sub to play right in your room. All are low distortion, low extension, high output subs. The goal is even response around the room, thus the reason so many are suggesting two subs. Then, proper placement and room correction, level, phase, etc. You do all those things right and the sub will mate up just fine.

Some have BIG budgets for subs. Myself, I don't and wanted a sealed 15" with some decent power for well under $1K. So, I am building a Stereo Integrity HT 15" powered by a Behringer EP2500 amp. Sub for $175 shipped, used amp $110 shipped, DIY flatpack enclosure $100 shipped, $100 for finish material etc, and will use Audyssey XT32 for room correction. However, if I had $1500 to spend on a manufactured sub system....and I had the space, I would want two subs and room correction software. Something like a couple of PSA sealed XS15 or ported XV15, and a mini DSP unit. The subs will cost $1500, the DSP and Mic about $175.

 

[fuzz092888]

1. For home theater LFE you are basically looking for good Low Frequency Extension and output to about 115 dB if ou want to bring the house down.

Well THX reference, which is what most receivers calibrate to, is only 105db peaks. Obviously being able to play louder than that most likely means it will hit 105 with low distortion. Also, what frequencies you want to hit at those levels will affect what type and how much you spend on a sub.

2. I think several have a parametric EQ, DSP control, etc. However, for more detailed room correction an outboard system (Like MiniDSP, Behringer feedback destroyer, REW, AntiMode, SMS-1, etc)might be needed.

Personally I like MiniDSP and REW. I feel that Antimode is well overpriced for what it does. The Behringer I don't find terribly user friendly.

3. Bottom line, you need a sub if you are going to belt out the low end effects. Its not so much a sub mating up better with your speakers as it is getting the sub to play right in your room. All are low distortion, low extension, high output subs. The goal is even response around the room, thus the reason so many are suggesting two subs. Then, proper placement and room correction, level, phase, etc. You do all those things right and the sub will mate up just fine.

Two subs will definitely help smooth out room response, but if it were me, I'd go for the biggest baddest sub I could. This leaves me open to an easy upgrade path in the future without spending more money than I needed to. If, however, you don't plan on upgrading then duals would be the better choice.

Some have BIG budgets for subs. Myself, I don't and wanted a sealed 15" with some decent power for well under $1K. So, I am building a Stereo Integrity HT 15" powered by a Behringer EP2500 amp. Sub for $175 shipped, used amp $110 shipped, DIY flatpack enclosure $100 shipped, $100 for finish material etc, and will use Audyssey XT32 for room correction. However, if I had $1500 to spend on a manufactured sub system....and I had the space, I would want two subs and room correction software. Something like a couple of PSA sealed XS15 or ported XV15, and a mini DSP unit. The subs will cost $1500, the DSP and Mic about $175.

The SI's are good drivers and really pack a punch. However, I'm a little underwhelmed by them, just because they don't dig as deep as I'd like them to. If I had $1500, it sure wouldn't be spent on any of the subs listed

 

[Tom V.]

Your own measurements undermine your assertion here. You do not fully gain that extra output because the port is facing the microphone on your subwoofer. As can be seen, any extra output gained by having the XV15 cone face the mic is minor.

Maybe you should read what I type? I already mentioned the primary gain is from 30-100hz in the post you quoted. And the link to "my own measurements" show a 1.3(ish) gain from 30-63hz. I said 1.5 to 2.5 as I was referring to the graph which goes all the way out to 100hz. The higher the frequency the more of a difference you will measure.

So my link to a single test session is 0.2 (point 2)dB off from my post you quoted and this now "undermines" my post somehow? Have you really become this desperate? Truly living up(down?) to your forum "handle".

Tom V.
Power Sound Audio

 

[Tom V.]

DON'T GET INVOLVED HERE TOM!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Thanks BSA for your input, appreciate it, the OP is probably gone now

I hear ya Blaze, how do I put PSA stalkers on the ignore list here?

Tom V.
Power Sound Audio

 

[Tom V.]

Re: the FV15HP vs the XV15, I'll see if I can make it simple:

Subwoofer	PSA XV15	Rythmik FV15HP
	#'s from PSA Website	#'s from DB, Native Tune
CEA 2010 - 16Hz	98.1dB (from DB)	102.1dB
20Hz-32Hz Avg	116.6dB	122.5dB
40-63Hz Avg	125.1dB	128.1dB
20-63Hz Avg	121.8dB	125.8dB
Output Ratio	1	1.6

<tbody>
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Cheers

That's looks about right. The XV15 deep response is between the two tunes on the rythmik. So you can cite the higher output mode and give up a little extension or vice-versa. You can have *TWO* XV15s delivered for the price of a single fv15hp and reap all the benefits of dual sub room smoothing. Then there's the 5 year warranty versus 2, made in USA with almost all USA sourced content, etc . So all things considered I don't feel the XV15 needs to make any apologies here. It takes a solid product to win "product of the year" 2012 Audioholics Product of Year Award Winners | Audioholics from Audioholics..

Tom V.
Power Sound Audio

 

[shadyJ]

Maybe you should read what I type? I already mentioned the primary gain is from 30-100hz in the post you quoted. And the link to "my own measurements" show a 1.3(ish) gain from 30-63hz. I said 1.5 to 2.5 as I was referring to the graph which goes all the way out to 100hz. The higher the frequency the more of a difference you will measure.

So my link to a single test session is 0.2 (point 2)dB off from my post you quoted and this now "undermines" my post somehow? Have you really become this desperate? Truly living up(down?) to your forum "handle".

Tom V.
Power Sound Audio

Your product page for the XV15 shows a 1.5 dB boost across the board, not just 30 Hz to 100 Hz. Normally I wouldn't quibble over a decibel or two, but the way you present your products and your competitors products is dishonest, and you need every extra decibel to make your specious comparison charts work. CEA is not accurate enough for measurements from different testers to be compared out to a tenth of a decibel. Anyway since you can not be trusted to accurately present data for the product of yours for which there is third party measurements, why should anyone trust your measurements for which there is no independent verification? All of your own measurements for your products should be considered suspect until corroborated by a reliable third party.

 

[its phillip]

Well THX reference, which is what most receivers calibrate to, is only 105db peaks. Obviously being able to play louder than that most likely means it will hit 105 with low distortion. Also, what frequencies you want to hit at those levels will affect what type and how much you spend on a sub.

Remember that the LFE channel will have 115dB peaks, 10dB above the other channels.

Also, with redirected bass from the other channels, the possibility exists that the subwoofer(s) would be asked to deliver 123 dB D:

 

[wldock]

The SI's are good drivers and really pack a punch. However, I'm a little underwhelmed by them, just because they don't dig as deep as I'd like them to. If I had $1500, it sure wouldn't be spent on any of the subs listed

The million dollar question...what would you get for $1500? DIY or manufactured?

IMO, subbass is a very cool thing but I would guess one would have to decide how much they are willing to spend. In my own system $1000 is the most I would consider spending. Anything more than that then.....I would want a new Pre/Pro, amps and speakers to increase performance of the "majority" other octaves as well as the video before i went subbass crazy.

I think the others have said it but, the OP needs to decide what his "end game" is for the current system and purchase his first sub, or subs based on that numeric figure. If he gets a $1K-$1.5 sub now...will he be willing to pay that for a second..or will a single be enough for him?

 

[fuzz092888]

The million dollar question...what would you get for $1500? DIY or manufactured?

Nah, not a million dollar question. Not to me at least. DIY all the way. With that budget DIY can provide a ton more performance for your money, IMO.

IMO, subbass is a very cool thing but I would guess one would have to decide how much they are willing to spend. In my own system $1000 is the most I would consider spending. Anything more than that then.....I would want a new Pre/Pro, amps and speakers to increase performance of the "majority" other octaves as well as the video before i went subbass crazy.

Infrasonic frequencies aren't the only reason to pay more for a subwoofer. Lower distortion, wider operating bandwidth up top, more headroom, etc are all reasons why subs are important. If you want to easily pressurize a room to reference levels, it can take a hefty investment.

I think the others have said it but, the OP needs to decide what his "end game" is for the current system and purchase his first sub, or subs based on that numeric figure. If he gets a $1K-$1.5 sub now...will he be willing to pay that for a second?

That's what I keep asking, but from his answers it would seem like he's still on the fence.<style id="pageBrightnessCustomCSS">body{zoom:175%;}</style>

 

[Sounder]

The OP is still here. Wow...lots of action since yesterday! Thanks for all the feedback! After doing a LOT of reading yesterday I am really leaning toward the Rythmik FV15HP for a couple of reasons.

1. From the charts I have seen it gets to a very low range where it seems more and more movie sound effects are going, which fits my taste in movies more than music.
2. It has the direct servo which seems like a great way to reduce THD and provide authentic, tight, accurate bass (rivaling sealed subs?).
3. It has a few nice onboard options like EQ which appeal to me since I don't have that option on my Marantz 6008 receiver.
4. It provides a great single sub option until if and when I choose to get the second sub. If I can get a discount for 2 then I might even spring and get the second one! I am guessing in a year or so this model will still be available if I choose to wait?

Can anyone make a case for the two sub option now with another brand versus buying the FV15HP and adding another later? Can two subs @ $700-$800 each get to the low bass frequency of the FV15HP or will it just give me louder bass in the given range with less power needed? Hopefully this question makes sense.

The other sub I was considering was the SVS PB13Ultra, but to me it feels like the extra performance (if any) isn't worth the extra cash for what I can get out of the FV15HP, especially considering I don't plan on shaking my foundation loose on a regular basis. As always, feedback is greatly appreciated.

 

[Sounder]

Given Fuzz's response about a DIY SUB, it is something I would be open to as I am fairly handy but would have absolutely no idea where to start. What DIY options can get a better performing sub than the FV15HP and what is meant by better?

 

[rojo]

Great questions, and I'm glad you're finding this helpful.

Sure, two subs are louder than one; but the benefit of using multiple subs is more for room correction than for boom. Using a single sub, you really have to take your time, perform the subwoofer crawl, and make adjustments a couple of inches at a time to find optimum placement of the sub for the best response in your primary listening position. Using multiple subs allows you to be a little more flexible with your sub placements, and can expand the sweet spot to a wider area. The drawback to this is that you'll need a minidsp, a good measurement mic, and patience to play with REW on a PC to optimize each sub's response in your room.

Re: diy, parts-express.com is a great place to look. You can build an 18" reference sub in a sealed cabinet and add all the hardware and a 1000+ watt amp for around a grand (depending on grille, veneer, casters, handles and whatever else you add to your project). Or run the amp joint stereo for a little less power than bridged, but add a second sub for about 500 bucks more. See this thread for some recent ideas.

Sent from my LG-VS980 using Tapatalk

 

[ahblaza]

I hear ya Blaze, how do I put PSA stalkers on the ignore list here?

Tom V.
Power Sound Audio

Tom, go into your account and select account settings, then click edit ignore list on the left side of that page under account settings and type in Troll Oh I mean Shady J
Jeffrey Nordi

 

[fuzz092888]

Given Fuzz's response about a DIY SUB, it is something I would be open to as I am fairly handy but would have absolutely no idea where to start. What DIY options can get a better performing sub than the FV15HP and what is meant by better?

If you've never built a sub before, and have limited experience with other wood working projects I probably wouldn't start off with a vented alignment if I were you. Sometimes they can be a little trickier, especially if you're building from scratch.

DIY sound group has some nice flat packs that can be purchased if you don't have the resources to build your own cabinet, or if you are worried about them being imperfect for a first time.

diysoundgroup.com

As for drivers, there are plenty out there at all price ranges. The nice thing about DIY is that you can most likely build two high quality 18" sealed subs for pretty close to that $1500 budget with an amp. The driver's I'm currently working with are the Mach 5 UXL 18's. I'm still building the cabinet so I don't have any performance information other than how they model, but they model extremely well in fairly small sealed cabs. They're about $480/driver including shipping to the CONUS and model nearly identically to the TC Sounds LMS Ultra, which is one of the kings of DIY drivers (and also about $1000/driver). It's going to be a little while before my project is complete, but if you're not in a rush I'll post performance data when it's done if you're interested.
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[shadyJ]

Tom, go into your account and select account settings, then click edit ignore list on the left side of that page under account settings and type in Troll Oh I mean Shady J

No, don't put me on ignore! Because then who will I get to build these wonderful strawmen for me!?

If you've never built a sub before, and have limited experience with other wood working projects I probably wouldn't start off with a vented alignment if I were you. Sometimes they can be a little trickier, especially if you're building from scratch.

DIY sound group has some nice flat packs that can be purchased if you don't have the resources to build your own cabinet, or if you are worried about them being imperfect for a first time.

diysoundgroup.com

As for drivers, there are plenty out there at all price ranges. The nice thing about DIY is that you can most likely build two high quality 18" sealed subs for pretty close to that $1500 budget with an amp. The driver's I'm currently working with are the Mach 5 UXL 18's. I'm still building the cabinet so I don't have any performance information other than how they model, but they model extremely well in fairly small sealed cabs. They're about $480/driver including shipping to the CONUS and model nearly identically to the TC Sounds LMS Ultra, which is one of the kings of DIY drivers (and also about $1000/driver). It's going to be a little while before my project is complete, but if you're not in a rush I'll post performance data when it's done if you're interested.

While the UXL looks like a phenomenal value, from what I can tell it is not quite on the level of the LMS Ultra. Databass isn't showing up at the moment, but the UXL doesn't quite match the output of the LMS down low and it had quite a bit more distortion, although the distortion graphs are not up for it because the driver died before that could be done. Another thing, Ricci had posted a bunch of excursion videos for many of the drivers, and the UXL ran into a lot more mechanical noise at a lower excursion than the LMS. It looks like it doesn't have the ability to do ultra long excursions clean like the LMS Ultra. Also it is not quite as linear as the LMS Ultra, the LMS plays flat even in a small box, it needs no EQ, which is one of the really cool things about it. The UXL was a little peakish in comparison when Josh tested it, although that was probably due to the small enclosure Josh uses. Still, the UXL looks like a great driver for the money. Some nice things about it, it doesn't look like it is quite the energy hog that the LMS is, so a 2 kW amp will go further with a UXL than a LMS. It also manages more mid and upper bass output than the LMS in Josh's tests, if I remember right. I am eager to see how the Ultimax 18 fares against the UXL, but the Ultimax is seemingly perpetually delayed.

One more thing, the UXL is $530 shipped, not 480.

 

[fuzz092888]

While the UXL looks like a phenomenal value, from what I can tell it is not quite on the level of the LMS Ultra. Databass isn't showing up at the moment, but the UXL doesn't quite match the output of the LMS down low and it had quite a bit more distortion, although the distortion graphs are not up for it because the driver died before that could be done. Another thing, Ricci had posted a bunch of excursion videos for many of the drivers, and the UXL ran into a lot more mechanical noise at a lower excursion than the LMS. It looks like it doesn't have the ability to do ultra long excursions clean like the LMS Ultra. Also it is not quite as linear as the LMS Ultra, the LMS plays flat even in a small box, it needs no EQ, which is one of the really cool things about it. The UXL was a little peakish in comparison when Josh tested it, although that was probably due to the small enclosure Josh uses. Still, the UXL looks like a great driver for the money. Some nice things about it, it doesn't look like it is quite the energy hog that the LMS is, so a 2 kW amp will go further with a UXL than a LMS. It also manages more mid and upper bass output than the LMS in Josh's tests, if I remember right. I am eager to see how the Ultimax 18 fares against the UXL, but the Ultimax is seemingly perpetually delayed.

Very true on all points. I'd only like to add two things. First, I would expect there to be performance trade offs on driver that is less than half the cost, which I knew going into it. I also said they model nearly identically, not that performance will be identical. Semantics, but an important distinction I think. the second is that some of the issues Josh had have been somewhat resolved due to the different dust cap and added venting since it had been tested by him. Obviously this won't suddenly boost its performance up enough to compete head to head with the LMS, but it will help a little.

One more thing, the UXL is $530 shipped, not 480.

You're forgetting that that's in CA dollars not US. After the conversion price is roughly $480 depending on the current exchange rate.