Boomzilla's Journey (ongoing)

[Boomzilla]

POWERSOUND AUDIO XV15 PORTED SUBWOOFER

This is a downward-firing 15" diver in a ported box with an internal plate amplifier. The box is well-braced and does not vibrate as much as the boxes of other subwoofers that I've owned. The amplifier has crossover frequency, phase, and gain pots. The power switch offers "off/on/auto." There is no 12 volt trigger. Inputs are RCA only and may be used either summed or stereo. The stereo option produced hum with my gear, but I didn't spend a lot of time troubleshooting.

The gain on the sub is designed to work fine with "normal" sensitivity speakers (probably from about 83 to 93 decibels at one watt at one meter). Lower sensitivity speakers can be accommodated by just turning down the sub gain knob some more, but higher sensitivity speakers will need some attenuation. This can be accomplished through an AV preamp or receiver, or by using a power amplifier with gain pots on the amp. Of the Emotiva offerings, only the Mini-X would be suitable, but with such sensitive speakers, the Mini-X would be a more-than-adequate match anyway.

Once adjusted to match the main speakers, I ran a frequency sweep from zero to 100 Hz. in five Hertz increments. By moving the subwoofer position in the listening room, I was able to overcome the majority of room peaks and dips. I get reasonably flat frequency response from 25 to 50 Hz. (the range that I'm running the sub). I have slightly attenuated response at 20 Hz. and no audible response at all below that.

This is the performance I'd expect from a sub designed primarily for home theater use. What the XV15 does that most subwoofers don't is produce that frequency range with high amplitude and (so far as I can tell) no doubling or significant distortion. I've had subs in my room before that went as low or lower than the XV15, but most didn't sound as clean. The only sub (to date) that I remember as being equivalent was a Definitive Technology Trinity sub. The Trinity not only played as loudly and cleanly as the XV15, but also went significantly lower. 10 to 15 Hz. was clearly felt with the Trinity. On the other hand, the Trinity is 2x+ the price of the PSA sub, so I'd expect it to do more.

For a sub-$1K subwoofer, the XV15 is probably as good as it gets. I believe that I could get lower extension for the same price in a different product, but at the cost of louder volumes. The XV15 plays louder than subs that go lower. I believe that I could get higher volume for the same price in a different product, but at the cost of bass extension. The XV15 chooses a very good compromise between low-frequency extension, distortion, and volume.

For home theater use, I doubt that one could better the XV15 for its price. For music use, there are more choices, but each requires different compromises. In music use, my XV15 blends with my main speakers seamlessly and provides an extra octave of music that is noticeable even on pop recordings. Unless you like car audio sound, match your levels judiciously - even a touch too much on the subwoofer gain, and you've turned your hi-fi into a boom box. But when you get things right, you'll realize that the subwoofer's cost was fully justified.

Thanks to all the Lounge members who steered me away from "full range" speakers and to the subwoofer option. This XV15 is definitely optimized for JUST bass in a manner that I've never heard from any full range speaker. Depending on the sound of the room after further ATS Acoustics treatment, I'll consider whether or not to add a second XV15. I certainly don't need the amplitude, but having a smoother in-room bass response might be worth the additional money.

I'm just not a "shake the house with dinosaur steps" kind of listener. I'll (once per year or so) cue up some DJ Magic Mike just to irritate my better half, but in general, even organ/deep synth music is conspicuous mostly in its absence. I do, however, enjoy jazz with sting bass, orchestral music with tympani, brass, and bass, and pop music with the occasional foray into the depths. This subwoofer will suffice for my needs and it does so for approximately half the cost of similar offerings from SVS and Rythmik.

Could I have built something equivalent for less money? Yes, I think I could have, BUT I'm no longer willing to spend the time doing construction projects - too much else goes on. Therefore, as a turnkey solution, the PSA XV15 is a good choice for me.

As I said, I did try the sub with some equalization. The result? Not enough difference to bother. I'm happy with the naked sub and its sound. So for others considering subwoofers, do check out PowerSound Audio. The owner, Mr. Tom Vodhanel, has been prompt, polite, and greatly helpful in responding to my emails for both pre-purchase advice and coaching me through setup. Taken in conjunction with the PSA products' very reasonable prices, I think that the subwoofers represent a true bargain.

[DYohn]

Your last post sounds like a description of pretty much what a properly designed subwoofer is supposed to do. By the way, I always use subs with every system, including high efficiency systems. The key is proper integration, and a preamp makes that easier both because of bass management and also because of sufficient output levels to properly drive the amplifiers. I'm glad you like the Power Sound system. I recommend kicking back, turning off your analytical brain, and enjoying some music.

[Boomzilla]

Sounds like a plan!

I almost scooped up some Klipsch RF-25 speakers at a yard sale this morning, but managed to resist. I don't need them at all AND I just bought a pair of KEF Q300s from jedinite24 here on the Lounge. I'm particularly interested in hearing how the KEF concentric tweeters sound in my room. If they're as great as I read, then I want me some used KEF Blades for just under 1/3 the new price!

Used the sub with a movie tonight (Ender's Game) and the XV15 did not fail to satisfy. Sound FX are really, Really, REALLY effects with the sub in the system.

I also amazed a friend by playing Peggy Lee's "Fever." It's a simple song with drums, string bass, and Peggy's voice, but the sub shows off the best of the drums & bass.

Also, I got the following comments from Mr. V at PowerSound Audio:

" I would be hesitant in applying much boost under 15hz. The system/enclosure is tuned around 18hz and a LITTLE under that shouldn't hurt anything. If the desire is for real "infra sound"....true extension into the 5hz to 8hz range for example....you can consider swapping out the XV15 for the XS30. I would predict extension into the single digits in your room environment, similar output capabilities in the 15-40hz range, and roughly double the output in the 45-100hz range (compared to the XV15). "

So the "sealed subs can go deeper" truism is correct - at least in the context of PSA products.

[Boomzilla]

Today I'm ripping my backlog of about 60 CDs. DBPoweramp isn't the fastest ripper I've used, but it seems to do a fine job. The WAV files that I'm getting sound identical to the discs that they came from, so all's good.

I'm also ripping some artists that I've never heard before just to try them out. It would have been quicker just to throw the disc in the drawer & decide whether or not they were keepers before ripping, but I often find that even on a disc of songs I don't care for, there's at least one song that's just amazing.

When playing through the library, I also find that a song that I have no initial affinity for stays on my mind so that a few days later, I want to hear it again. Therefore, if I decide that I don't want a track, I move it to the "maybe" folder before deleting. That way, if I change my mind, I can just reimport it to the library without having to rerip.

My "ripped disc storage shelf" is also filling up. I've got storage for only about 1,800 discs. I never thought I'd outgrow it, but you never know.

Some box sets need to go. I'll post them on the Emporium soon.

Cheers - Boomzilla

[Boomzilla]

Mr. Garbulky was kind enough to drop by this evening & help me sort out the subwoofer. I'll leave it to him to say what he thought of the setup, but I thought it sounded much better when he left than when he arrived - Thanks!

[garbulky]

Feb 16, 2014 22:19:03 GMT -5 Boomzilla said:

Mr. Garbulky was kind enough to drop by this evening & help me sort out the subwoofer. I'll leave it to him to say what he thought of the setup, but I thought it sounded much better when he left than when he arrived - Thanks!

No, thank you! I had a great time at your place. I hope I didn't bother your better half too much with all the shaking the house at 15 hz!
I hope to write up a post on it. But for now, let it suffice to say that I find the Heresy's to be superior to the Cornwal 3's. It also has an "enticing" sound to it - namely in the treble. Hard to describe so I have to think about it.
I also got to hear some new artists like Allen Toussaint - a new orleans native!

[Gary Cook]

Glad you are liking the 2.1 set for stereo music, I've had mine that way for decades, despite much derision from hifi buddies, especially early on. My rule of thumb for the sub woofer amp has always been to have its wattage 3 to 4 times the FL and FR amp wattage. Since I added the XPA-5 (200 watts per channel) a couple of years ago I've been running at double with a 400 watt sub amp. I'm still doing that with an XPA-100 as a sub amp. This is with main speakers in the 92 db to 96 db efficiency range.

Also worth considering, if you are using XLR (balanced) connections from the Oppo to the XPR-2 you are +6db over an RCA connection (unbalanced) to the sub amp.

Your situation is that you have 600 watts per channel from the XPR-2 for the FL and FR and 500 watts from the sub amp. Personally whilst I don't think the 98 db efficiency main speakers are helping, your real problem may well be the amps' power differential being the inverse of what works for me (and that many recommend). My view would be that a second XV15 would raise the sub wattage (1000 watts) versus main speaker wattage (600 watts) closer to that recommended (ie; almost double) .


Cheers
Gary

[Deleted]

You may find these organ recordings of interest (then of course you also may not ... ), I love them - they're true LF workouts with great verve, depth, punch and good 'ol plain musicality...as Larry Greenhill in Stereophile waxed lyrical over recently...

Christopher Herrick: Organ Fireworks IV
Music by Batiste, Bonnet, Bourgeois, Buck, Johnson, Handel, Lefébure-Wély, Lemare, Shostakovich, Vierne, Whitlock, Widor
Christopher Herrick, Organ of St. Bartholomew's Church, New York
Hyperion CDA66605 (CD). 1992. Paul Spicer, prod.; Christopher Greenleaf, eng. DDD. TT: 75:00



A fellow pipe-organ and subwoofer devotee and Stereophile reader clued me in to Christopher Herricks's 11 volumes of Organ Fireworks: recordings of 19th- and 20th-century organ music. Vol.IV features Herrick playing the 1918 Skinner/Hutchings pipe organ of St. Bartholomew's Episcopal Church, in New York City. Revised in 1971 by Aeolian-Skinner, it comprises 168 stops and 225 ranks. The recording captures the power and massiveness of the deep bass pedal chords, particularly in the Allegro of Widor's Organ Symphony 6. The clarity of the instrument's flute, orchestral reed, and brassy trumpet stops is startlingly evident in Dudley Buck's rousing Concert Variations on "The Star-Spangled Banner." The explosive, fortissimo ending of Shostakovich's Passacaglia will test the limits of any woofer, and makes this a recording I can't forget. No other recording quite yields the organ's sustained musical power or so clearly delineates its descending scales, or makes it so easy to determine a subwoofer's pitch definition or eases its ability to create "room lock" in my large listening area.

Scott Dettra: Majestus
Music by Barber, Bingham, Copland, Dupré, Franck, Howells, Walton, Willan
Scott Dettra, Great Organ of Washington National Cathedral
Loft LRCD-1114 (CD). 2009. Roger W. Sherman, prod., eng., mastering. DDD. TT: 65:15



Scott Dettra's program of "large-pipe organ" favorites was the final recording made of the Washington National Cathedral's Great Organ before it was replaced. Installed in 1938 and upgraded in 1975, the instrument had four manuals and 189 ranks. The pedal rank consisted of 37 pipes, including one 64', four 32', and eight 11' pipes. The liner notes detail the engineer's use of "proprietary 24-bit" technology, and the absence of any transformers in the signal path that might have produced upper-bass boom when reproducing the deepest pedal chords. Majestus has the widest dynamic range of any pipe-organ CD in my collection, justifying its warning label: "can damage your equipment if played too loudly." That warning should be heeded: Track 1, Copland's Fanfare for the Common Man, features two 8' pedal ranks and explosive bass-drum whacks. Thunderous pedal chords engaged the full power of a Revel Rhythm2 subwoofer (review in progress), producing terrific room lock and a sense of massive pressure—as I also heard with Dupré's Prelude and Fugue in B, Op.7 No.1, and Walton's Coronation March: Crown Imperial. The power, dynamic range, and great deep-bass extension of Majestus make it my reference recording for deep-bass pipe-organ music.

[Boomzilla]

Blooloo - THANK YOU for the recommendations - I'm Amazoning them right now! May I recommend to you "Bachbusters" by Don Dorsey. It's synth - not organ, but the recording and nimbleness of the notes are a revelation compared to "true" organ recordings.

Gary - THANK YOU for the recommendations. My initial impression is "Hush your mouth! You're going to cost me LOTS of money." LOL - I'm not sure that my wife would go for a second subwoofer - She doesn't like the effects of the first (especially on movies). What I may have to do is just turn the sub off when she's watching a movie with me and turn it on when she isn't. Since I don't listen as loudly on music, she can live with it there.

Garbulky - THANK YOU again for your company and your setup assistance. I plan to move back to the DefTechs today so that I can see whether or not the sub will blend with them as neatly as the Heresys. I also plan to go back to using the bass management of the Oppo with the crossover at 80 Hz. and the XPR-2 driven with the RCA jacks of the 7.1 outputs. Since the DefTechs are SIGNIFICANTLY less sensitive than the Heresys, I'm thinking I can get a level match without too much trouble. I think that I'm also going to fiddle some more with sub placement. It's reasonably smooth where it is, but if you can localize the sub from its sound (I can't), then we can probably do better.

Next month when my preamp arrives, I think that many of the bass level matching issues will go away. Since the preamp will be dividing an already level-matched signal, the only gain issues to be dealt with will be the sub level vs. the gain of whatever power amp I'll be using. If Mr. Cook is right, though, and a "2x the amplifier wattage" is a reasonable estimator for sub power, then a second sub MAY indeed be required.

Finally, Mr. Tom Vodhonel of PSA makes the following comment regarding main amp power vs. sub power when using two subs: "One benefit is...the significant reduction in amplifier requirements for a given output level. As I'm sure you know, the wattage is quartered. So if you need 300 watts to "keep up" with high efficiency speakers at louder levels....that would be reduced to 75w (from each amplifier). It is counter intuitive for most but by ADDING a second subwoofer you often reduce the amperage requirements for the home audio system." If I understand this comment, Tom's talking about the subwoofer amps, not the main amps - By using two subs, each sub amp uses only a quarter the wattage (of a single sub amp) to produce the same acoustical output.

Cheers - Boomzilla

[garbulky]

I'm glad you are figuring this stuff out. I have no experience with "real" subwoofers. The subs I used to have were so pathetic they aren't even worth mentioning. I hope that pre-amp comes in soon!

[monkumonku]

Feb 17, 2014 7:36:30 GMT -5 Boomzilla said:

I'm not sure that my wife would go for a second subwoofer - She doesn't like the effects of the first (especially on movies). What I may have to do is just turn the sub off when she's watching a movie with me and turn it on when she isn't. Since I don't listen as loudly on music, she can live with it there.

Cheers - Boomzilla

As I recall, initially you said your wife was opposed to any sub which was why you didn't have one in your setup. But now you have this behemoth. So it is only a matter of time before you wear down your wife and have dual and then quad subs, correct?

[pop]

I would recommend you get 2. Less power needed from the subs to create a desired effect therefor an easier blend with your efficient speakers. However, if the wife isn't liking one, she is going to despise 2.

I am assuming since your wife let you buy it, she doesn't like it because it is too intense?

I watched Enders Game last night and where I really thought the movie was just decent, I was locked in by the soundtrack. The sheer force from the subs created an insane immersing feeling. I could see where this might be too much for some people.

[Boomzilla]

I've owned many subs before including some SOTA ones. I've also owned some junk & some music reproduction subs (which are COMPLETELY different animals).

A good sub is a thing of beauty to hear. A bad one, a never-ending PITA. I think my XV15 is one of the former. Today, I'm re-situating it to a position directly between the speakers. This will minimize wire runs & clean up the rat's nest behind the equipment stands.

Last night, we played a frequency sweep from zero to 100 Hz. in five Hertz increments and at a fairly loud level. We could hear the cone jumping even at one Hz. By 15 Hz. we had audible output; by 25, we were setting off car alarms in the parking lot next door. We turned it down...

Fortunately, my wife is more tolerant of subsonic frequencies when company is here, so Garbulky was worth his spiced cider so that we could experiment with the LF abilities of the sub.

The thing that surprises me the most about the subwoofer is that non subsonic frequencies are so enhanced by it. We have listened to and enjoyed many a recording with bass content with the DefTechs alone and not noticed any real deficiency in the bass. The extra octave of the subwoofer, however, adds weight and timbre to the spectrum in a manner that enhances the presentation of the whole. Not even the Paradigm Eclipse BP speakers (with a -3dB point of 28 Hz.) come anywhere close to the bass verisimilitude of the subwoofered system.

Bravo Powersound Audio! Well done.

[pop]

Feb 17, 2014 10:16:41 GMT -5 monkumonku said:

Feb 17, 2014 7:36:30 GMT -5 Boomzilla said:

I'm not sure that my wife would go for a second subwoofer - She doesn't like the effects of the first (especially on movies). What I may have to do is just turn the sub off when she's watching a movie with me and turn it on when she isn't. Since I don't listen as loudly on music, she can live with it there.

Cheers - Boomzilla

As I recall, initially you said your wife was opposed to any sub which was why you didn't have one in your setup. But now you have this behemoth. So it is only a matter of time before you wear down your wife and have dual and then quad subs, correct?

I am contemplating adding 2 more XV15s. The 2 of them already scare me, I think 4 and I will have to take a trip to costco for a bulk supply of depends underwear.

[RightinLA]

Feb 16, 2014 23:13:32 GMT -5 Gary Cook said:

Glad you are liking the 2.1 set for stereo music, I've had mine that way for decades, despite much derision from hifi buddies, especially early on. My rule of thumb for the sub woofer amp has always been to have its wattage 3 to 4 times the FL and FR amp wattage. Since I added the XPA-5 (200 watts per channel) a couple of years ago I've been running at double with a 400 watt sub amp. I'm still doing that with an XPA-100 as a sub amp. This is with main speakers in the 92 db to 96 db efficiency range.

Also worth considering, if you are using XLR (balanced) connections from the Oppo to the XPR-2 you are +6db over an RCA connection (unbalanced) to the sub amp.

Your situation is that you have 600 watts per channel from the XPR-2 for the FL and FR and 500 watts from the sub amp. Personally whilst I don't think the 98 db efficiency main speakers are helping, your real problem may well be the amps' power differential being the inverse of what works for me (and that many recommend). My view would be that a second XV15 would raise the sub wattage (1000 watts) versus main speaker wattage (600 watts) closer to that recommended (ie; almost double) .


Cheers
Gary

In a typical room (even in Boomzilla's larger than average room) you are not going to be running any where near that kind of wattage for the FL and FR, however I do recommend dual or even four subwoofers for the basic reasons given. I've had very good success with using multiple subs. Given Boomzilla's main audio room, I believe he will have great success with multiple subs. It would really make the moniker "Boomzilla" a reality!

[monkumonku]

Feb 17, 2014 10:24:37 GMT -5 pop said:

Feb 17, 2014 10:16:41 GMT -5 monkumonku said:

As I recall, initially you said your wife was opposed to any sub which was why you didn't have one in your setup. But now you have this behemoth. So it is only a matter of time before you wear down your wife and have dual and then quad subs, correct?

I am contemplating adding 2 more XV15s. The 2 of them already scare me, I think 4 and I will have to take a trip to costco for a bulk supply of depends underwear.

You can always use the Depends for room treatments, too.

[pop]

Feb 17, 2014 10:33:56 GMT -5 monkumonku said:

Feb 17, 2014 10:24:37 GMT -5 pop said:

I am contemplating adding 2 more XV15s. The 2 of them already scare me, I think 4 and I will have to take a trip to costco for a bulk supply of depends underwear.

You can always use the Depends for room treatments, too.

Un-shatted of course. I wonder if they have a nice paisley pattern?

[melm]

Boom:

Your experience mirrors mine. The XV15 is really a first class sub, and I have been continually surprised at the positive effect on music. Not just 'sub-breakers', but day to day jazz and classical. I just have one sub, and will stay that way. The XV15 does very well in my room, and has really enhanced the Maggies.

Glad you took the plunge.

Mel

Feb 17, 2014 10:23:30 GMT -5 Boomzilla said:

I've owned many subs before including some SOTA ones. I've also owned some junk & some music reproduction subs (which are COMPLETELY different animals).

A good sub is a thing of beauty to hear. A bad one, a never-ending PITA. I think my XV15 is one of the former. Today, I'm re-situating it to a position directly between the speakers. This will minimize wire runs & clean up the rat's nest behind the equipment stands.

Last night, we played a frequency sweep from zero to 100 Hz. in five Hertz increments and at a fairly loud level. We could hear the cone jumping even at one Hz. By 15 Hz. we had audible output; by 25, we were setting off car alarms in the parking lot next door. We turned it down...

Fortunately, my wife is more tolerant of subsonic frequencies when company is here, so Garbulky was worth his spiced cider so that we could experiment with the LF abilities of the sub.

The thing that surprises me the most about the subwoofer is that non subsonic frequencies are so enhanced by it. We have listened to and enjoyed many a recording with bass content with the DefTechs alone and not noticed any real deficiency in the bass. The extra octave of the subwoofer, however, adds weight and timbre to the spectrum in a manner that enhances the presentation of the whole. Not even the Paradigm Eclipse BP speakers (with a -3dB point of 28 Hz.) come anywhere close to the bass verisimilitude of the subwoofered system.

Bravo Powersound Audio! Well done.

[Boomzilla]

My wife's ears are more delicate than mine. Her ears hurt at high SPLs, and particularly when the frequencies are low. She sticks her fingers in her ears when we're at a traffic light and a "boom box car" is proximate. She also wears ear plugs when we go to the theater. She doesn't like subwoofers for that reason. On "normal" music where there are no really, really low frequencies, the sub doesn't bother her too much. But when there are any extremely low frequencies, she leaves the room & shuts the door. Fortunately for me, she's willing to tolerate the sub provided I don't play it too loudly. I can live with that, so it works out fine. When we have company that wants the boom, she allows me to turn it up without complaint. I'm lucky to have her!

Unless I have SEVERE standing wave problems, I'm thinking that a single sub will do. We'll see...

[monkumonku]

Feb 17, 2014 11:03:28 GMT -5 Boomzilla said:

My wife's ears are more delicate than mine. Her ears hurt at high SPLs, and particularly when the frequencies are low. She sticks her fingers in her ears when we're at a traffic light and a "boom box car" is proximate. She also wears ear plugs when we go to the theater. She doesn't like subwoofers for that reason. On "normal" music where there are no really, really low frequencies, the sub doesn't bother her too much. But when there are any extremely low frequencies, she leaves the room & shuts the door. Fortunately for me, she's willing to tolerate the sub provided I don't play it too loudly. I can live with that, so it works out fine. When we have company that wants the boom, she allows me to turn it up without complaint. I'm lucky to have her!

Unless I have SEVERE standing wave problems, I'm thinking that a single sub will do. We'll see...

The advantage of dual or multiple subs should not be louder bass, but smoother bass that also doesn't put a strain on the amps in the subs because each has to contribute a lower SPL. If your room truly has the issues you've mentioned in the past, then perhaps multiple subs would overcome those issues. Personally I think some people get carried away with bass and just like it to "impress" by shaking the house but then that's not balanced and also not natural or realistic - same as those morons whose cars (and brains) are falling apart/have fallen apart because they have the bass turned up so high. So it wouldn't necessarily be to achieve a higher SPL but to achieve a better sounding system. If you are happy with the sound now then I would say just use the one sub. BUT you will never know what sort of improvement two subs would make unless you try it. And you know you like trying things so much that you won't be able to resist. And really, the SPL should not be louder with two subs, but the bass should be smoother and better distributed, which might even make it more acceptable for your wife.