Subwoofer humps [Archive] - Audioholics Home Theater Forums

jeffsg4mac

12-26-2003, 03:11 PM

I have a Paradigm PDR 10 that sounds great, but I have a huge peak at around 48 to 50hz. By huge I mean about 10 or 12 db's acording to my sound level meter and the AVIA sweep tones. What are some ways I might correct this. It does not have a phase switch, should I reverse the leads inside the sub? Thanks for any advice in advance.

annunaki

12-26-2003, 05:17 PM

Try different placement within your room. Your sub is probably in a bass  "mode", or an area in which the above said frequencies are amplified. Here is an equation to figure out your room's resonances.  

Speed of Sound (1129 feet/ sec.)
____

Resonance (in Hz) = 2x Room dimension
(in feet)

You can use this to figure the resonance of the length, width, and height. This formula will give you the primary resonance for each dimension. Simply multiply by 1,2,3,4,ect. to find axial resonances.

Example:

Room is 15 L x 12 W x 8 H

Resonance L 1129/(2x15)=37.63 hz axials (75.26, 112.89, 150.52)

Resonance W 1129/(2x12)=47.04 hz axials (94.08, 141.12, 188.16)

Resonance H 1129/(2x8)=70.56 hz axials (141.12, 211.68)

You shouid be able to reaffirm this by using a handheld db meter from radioshack. These resonances usually will occur at the front and back of the room as well as other places. You should be able to find a bass node in the room as well with your meter. A node is actually a dip in frequency response. By placing your subwoofer in a node on a wall that does not accentuate the frequencies you are having a problem with you will help to tame your rooms resonances.

Get your room dimesions and go to http://www.guidetohometheater.com and click on "The Sweet Spot". There is a free program that can calculate all of your rooms modes and node peaks and nulls and help you place your sub properly.

References: Stereophile Guide to Home Theater July/August 2003, December 2003

jeffsg4mac

12-26-2003, 08:36 PM

Thanks for the info, I will mess around with it this weekend <img src="http://www.audioholics.com/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>

Rob Babcock

12-27-2003, 01:45 AM

Sounds like a job for a Parametric Equalizer:  they are designed for just such problems.  I use a Behringer BFD DSP1124 and it works extemely well for sub eq.  Another interesting product is the SOS subwoofer optimizer- it's a single band parametric eq that is completely automatic.  It comes with a mic and test tones, you plug it in an let it play for awhile and it sets the curve on its own.

Placement helps, but in many rooms you just can't get the bass truly flat without some eq.  And parametric EQ is a helluva lot more precise than graphic EQ.

BTW, the Behringer is only about $125, the SOS is $300.  Haven't tried the latter but have read some positive press.

Trust me, it's a bit of work and has a bit of a learning curve, but this is one of the big eye/ear openers you'll ever try.

jeffsg4mac

12-27-2003, 07:54 AM

Thanks for the info, I had been looking at the audio control richter scale III, it is about $300 and has a mic and tones, but I like that SOS subwoofer optimizer better. That looks like the answer I needed. Thanks  <img src="http://www.audioholics.com/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>

annunaki

12-30-2003, 06:57 PM

An important rule of thumb for audio is this. One cannot really judge performance of a systems capabilities until variables are removed. By doing proper setup and placement, and then worrying about any peaks or dips in response. One can then make the use of an equalizer much more effective.

Rob Babcock

12-31-2003, 03:31 AM

The Richter Scale is a very nice piece, too, flexible and powerful.  That said, truly parametric EQ is more flexible yet.

Naturally, proper setup is a given.  Once you've got everything placed as well as you can and dialed in, then it's time to start EQ'ing.  

It's hard to everstress just how much more open and effortless your system sounds once the bass is EQed.

jeffsg4mac

12-31-2003, 08:52 AM

Well I changed to placement of the sub and was able to shift the hump from around 50hz to 38 or 40 and it is not as high. Now I need to get one of the EQ's to get correct. 50hz and above is the worst place to have a peak, that is where that infamous boomy sound starts in.

annunaki

12-31-2003, 05:39 PM

Rob, you are very correct in your assumption. Having a well eq'ed "flat" response curve does seem to suggest an 'effortless' type of sound.

Jeff, good job in shifting your resonance peak down in frequency. Anytime a resonance starts to occur around 50 cycles and above it becomes very obvious. Having a large resonance in the 50-500 cylces range can wreak havoc on a soundstage and overall resolution.

vinyl

01-02-2004, 08:13 AM

The PDR 10 is an irritant one note boom-box.......Great for the money though........Used to have one.

You have done well in your exercise to get the most from it.

Eq's are good.......but , don't waste any more money on this box......It's limits have been achieved.

Suggestion.....sell it........Get a real true sub that has definition in its notes.........Not that droning tension headache sound.

This is not a put down to you sir......just my subjective view of this product....... from past experience with it.

Good Luck,

jeffsg4mac

01-02-2004, 08:22 AM

Vinyl, I do plan on getting another sub, the PDR 10 was the most musical sounding sub I could find under $400 at the time, but I do want a better one. What do you think of the Servo-15 or the PS1200 from paradigm?

vinyl

01-02-2004, 09:07 AM

In the U.S. from what I read on other forums , SVS and HSU seem to get a lot of praise , both internet vendors.

I have a long.......love/hate with woofers.....over the years I have learned what DIMINISHING RETURNS means in both audio and video.

Servo 15 is good......and pricey.

What is keeping me happy at the moment ??........ the VELODYNE CHT 15.......Biggest Bang for buck ........in every way.....in your neck of the woods $500 -$600......investigate !

jeffsg4mac

01-02-2004, 09:31 AM

Thanks Vinyl, I will look at those others. I am leary on using a velodyne for music though, I had one of their 10in subs and was very unhappy with it on music.

P.S I just looked at those subs, while the HSU did'nt blow my skirt up the SVS PB1-ISD did. I looks like a helluva deal for $600 bucks.

vinyl

01-02-2004, 11:28 AM

A good woofer does not distinguish between music nor nuclear energy.

I have a dedicated room for music only.......I kept an old VELODYNE CT IOO in there to acompany my VANDERSTEEN'S..... configured with separates , line level , hi-pass filtering my mains @ 80 hz. for a long time.

The CT 100 job was to provide the foundation of the music...... and relieve my mains of that burden.......resulting in a bi-amped system .... *better clarity in midrange and highs..... and it did exactly that...... nicely.

It didn't take me all the way home , but it was 50% better.....
the CHT 15 brings my musical journey to 80/90 % home.

How much is the xtra 10/20 % worth ??*WILL YOU HEAR IT ??

This is all subjective you understand !......SO , I'll just keep going...........The CT100 has the flexability in it's back control panel to allow different configurations........where the PDR 10 does not........OVERALL even without the flexability there is simply no contest in quality of sound.

I don't know which VELO 10 you had.........BUT, you did say the PDR 10 sounded great........The VELO should have sounded magnificent in comparison..........SOMETHING WAS AMISS THERE. *

You don't state taste in music...... nor sound levels........

PS.......I don't receive commisions from Velodyne

* <img src="http://www.audioholics.com/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>

jeffsg4mac

01-02-2004, 12:49 PM

Vinyl, that is the one I had, the CT 100, I thought it was very muddy compared to the paradigm and did not have the authority in the bottom end. The only thing it had different if I remember correct was a phase switch. I listen to a broad spectrum of music but mostly jazz/fusion. Metheny, DiMeola,ect. At that time I had a marantz AV550 pre/pro with an adcom 5 channel amp and mirage all around. I now have a Denon 2803 and paradigm all around. Those SVS subs look killer for the price, I would like to hear one before I buy one though.

I don't get a commission from paradigm either <img src="http://www.audioholics.com/iB_html/non-cgi/emoticons/biggrin.gif" border="0" valign="absmiddle" alt=':D'>

vinyl

01-02-2004, 04:34 PM

jeff........Lets cut to the chase , shall we...... <img src="http://www.audioholics.com/iB_html/non-cgi/emoticons/tounge.gif" border="0" valign="absmiddle" alt=':p'>

I agree with audition on the SVS..... Buy more then you need.....You'll thank me in the morning.

My impressions of the SVS is that it appeals to head bangers (I may be wrong)....... ARE YOU ??

If it's music only..... I recomend VANDERSTEEN'S 2WQ....But it requires separates........ Or a receiver with both mains in/preouts.......Not recomended for HT.

For HT. VANDERSTEEN makes the V2W.......Both @ $1200 U.S.........Better than the SERVO 15 and the CHT 15. *

Investigate VANDERSTEEN !! *

My HT. room consists of 4 PARADIGMS ATOMS + CC170......
The ATOMS are wall mounted 2 up-front 2 in-rear......So much for PARADIGM.......Is this sounding familiar , somewhat ??

My room is 30'x32' open concept with a 14" ceiling beam at the centre of the space............The EAST wall occupies the VIDEO and all of the hardware.........Seating is 14' from the TOSHIBA.....The rears are 6' behind and mounted 8' high on the beam.

On the opposite side....... The WEST wall is my AUDIO area...... SO , now picture 2 couches back to back......in the centre of the room.......one facing VIDEO and the other facing MUSIC.......

This is not to impress..... but to clarify.

For me...... the future for my music is the VANDERSTEEN......
$1700 CAN........

For the VIDEO section the CHT 15 is a dragon slayer. <img src="http://www.audioholics.com/iB_html/non-cgi/emoticons/mad.gif" border="0" valign="absmiddle" alt=':angry:'> *

Now , don't be hasty in your selection..... you still have a woofer...... so , no rush really is there ??

Hope this helps,

* * <img src="http://www.audioholics.com/iB_html/non-cgi/emoticons/biggrin.gif" border="0" valign="absmiddle" alt=':D'>

jeffsg4mac

01-02-2004, 05:08 PM

Vinyl, with all due respect I have never liked the sound of vandersteens passive radiator designs. They sound, well sort of spongy, squishy, sort of trailing behind. It is not just vandersteen but all passive radiators that I don't like. Not a good choice for a sub design. IMHO, Paradigm PW-2200 would kill the vandersteen of that I have no doubt and the Paradigm is only $899 I believe. Still that is 300 more than I want to pay at this time. Which is why the SVS looks so attractive. I have Paradigm mini-monitors and the CC 370 up front with the atoms in the rear. I am looking into getting the monitor 5's up front and moving the mini's to rear side and adding the adp 170 to the surround back. I also have a pioneer 563a dvd player for SACD and DVD A, a philips dvd player for movies and regular audio CD's and a Hughes HDTV receiver All connected to a Denon AVR 2803. All that sitting in a corner on standesign rack with a 47in panasonic HD widescreen in the middle <img src="http://www.audioholics.com/iB_html/non-cgi/emoticons/love.gif" border="0" valign="absmiddle" alt=':love:'>  I am only lacking the bass dept at this time. The PDR 10 is good but not breathtaking. I want breathtaking bass for both music and HT. I'll pay more if I have to, like you said I am not in a hurry.

vinyl

01-02-2004, 07:38 PM

jeff , *Great chat,

It reinforces the broad interest of the hobby , from soup to nuts.

I'll leave you with a quote , *that I heard eons ago it seems ,

I didn't quite understand it fully then , but over the years it became clearer , till I finally understood the true meaning of it........ hence , I've applied it to my every day life ever since.

Are you ready ??...(man such build up) <img src="http://www.audioholics.com/iB_html/non-cgi/emoticons/rock.gif" border="0" valign="absmiddle" alt='???'>

" MOST PEOPLE , DON'T KNOW WHAT THEY WANT , BUT , THERE PRETTY SURE , THEY HAVEN'T GOT IT "

Good luck in your quest.

jeffsg4mac

01-03-2004, 08:43 AM

Ain't that the truth <img src="http://www.audioholics.com/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>

annunaki

01-07-2004, 02:56 PM

I would also suggest a velodyne woofer. I have the HGS-10 it it is a truly wonderful subwoofer. It reaches down to the depths of human percetion and then goes deeper. It then shocks you with it's amazing subtlety and musical ability. This has been my single best purchase in home theater. It is quite pricey at $1,899.00 retail but if you can afford it or one of its more affordable cousins (SPL Series II, DLS series,)you surely will not be disappointed. I know it sounds like they paid me to say this, but I am truly happy with what this woofer is capable of. Like Vinyl stated previously, you cannot spend 'too much' when it comes to getting a great subwoofer. If you can afford a little extra for a woofer spend it. Also, like stated above, have patience and listen, and find what truly pleases you.

av_phile

01-08-2004, 10:10 PM

With most reviews and reactions from colleagues, there are very few subwooofers out there that are excellent for music.  Vandersteens and RELs are often mentioned.  But I think they start above $1000.  Maybe some pre-owned outlets have them at half the SRP.

Yamahaluver

01-09-2004, 04:28 AM

Add the Yamaha and Paradigm to your wish list too, both are quite good.

Rip Van Woofer

01-10-2004, 11:45 AM

Lots of good advice here! Another tack I've heard that can be effective is to have two subs, one per channel. They cancel each other's node peaks out (with some attention to placement, of course). I have even heard of using two *different* subs, say one big honker for the real deep bass and a smaller one for 50hz or so on up, for the same purpose.

But, like with real estate, I agree that the first key to sub performance (and good bass performance with full range speakers) once you have a good unit(s) is location, location, location (placement).

Be aware that you can reduce peaks but can't fill in response holes with any kind of EQ. Only placement can fix or minimize those. The holes can bedevil you more than the peaks in my experience!

Another note: there are pretty good cheap PC and Mac based spectrum analyzer shareware programs out there. You can use your basic PC mic with them. Not laboratory grade by any stretch but good enough! Search downloads.com. I use one on my Mac called iSpectrum that cost the kingly sum of US$29. Works fine!

Or, you could try a setup like this! (http://www.dself.dsl.pipex.com/ampins/failproj/failproj.htm#p7) <img src="http://www.audioholics.com/iB_html/non-cgi/emoticons/tounge.gif" border="0" valign="absmiddle" alt=':p'>

Yamahaluver

01-10-2004, 12:42 PM

I would agree with Rip, I am using two subs in front and one in rear with my rear speaker set to LARGE in speaker management and I get very good clean bass from this setup.

Rip Van Woofer

01-11-2004, 12:39 PM

<table border="0" align="center" width="95%" cellpadding="0" cellspacing="0"><tr><td>Yamahaluver : I am using two subs in front and one in rear
Holy $#*"! I hope you don't live in an earthquake zone! <img src="http://www.audioholics.com/iB_html/non-cgi/emoticons/wow.gif" border="0" valign="absmiddle" alt=':O'>

mwc

01-12-2004, 05:09 PM

Rip, are the spectrum analyzer programs easy to use and where could one find out how to use them in a HT application? I'd like to find out what I'm getting into before I buy one.

I tried  this (http://www.dself.dsl.pipex.com/ampins/failproj/failproj.htm#p) but it was too complex.

Rip Van Woofer

01-12-2004, 09:19 PM

Hate to tell you, but the head gear is absolutely necessary! *<img src="http://www.audioholics.com/iB_html/non-cgi/emoticons/wink.gif" border="0" valign="absmiddle" alt=':;):'>

Yes, they're easy to use, but you need a microphone (the one that came with your computer is adequate, or buy one that will plug into your sound card) and some sort of test signal, whether via a signal generator or a CD with test tones. Linkwitz has a good test CD for $20. That's what I use. See link at end of this post.

Basically, place the mic (plugged into your sound card) in your listening position, launch the spectrum analyzer, fire up the test tones, and watch what happens. You want the various tones to be as near the same dB level as possible. If using pink noise, you want the sort of fuzzy response curve you'll see to be as flat as possible (pink noise response curve is most useful above 200 hz or so -- good for finding midrange and high freq. irregularities).

I hasten to point out, however, that a spectrum analyzer is maybe more than you need. It's just kind of audio-geeky and fun if you like that sort of thing (I do). If you slowly sweep the bass frequencies from about 200 hz down to 20 hz (the Linkwitz CD has a track that does that), you'll HEAR the peaks & valleys in your bass response easily enough, and thus will be able to hear the results of your placement changes until the sound is as nearly uniform as you can get it. An analyzer will not tell you anything about where to put the speakers -- it's still trial & error.

Most of the software-based analyzers have instructions -- some more, some less. And you can download demos to try before buying. You can learn a lot just playing around with the demo.

Linkwitz test CD (http://www.linkwitzlab.com/burst-cd.htm)

Yamahaluver

01-12-2004, 09:29 PM

<table border="0" align="center" width="95%" cellpadding="0" cellspacing="0"><tr><td>Rip Van Woofer : <table border="0" align="center" width="95%" cellpadding="0" cellspacing="0"><tr><td>Quote (Yamahaluver @ Jan. 10 2004,11:42)</td></tr><tr><td id="QUOTE">I am using two subs in front and one in rear
Holy $#*"! I hope you don't live in an earthquake zone! <img src="http://www.audioholics.com/iB_html/non-cgi/emoticons/wow.gif" border="0" valign="absmiddle" alt=':O'></td></tr></table>
<img src="http://www.audioholics.com/iB_html/non-cgi/emoticons/biggrin.gif" border="0" valign="absmiddle" alt=':D'> *<img src="http://www.audioholics.com/iB_html/non-cgi/emoticons/biggrin.gif" border="0" valign="absmiddle" alt=':D'> *<img src="http://www.audioholics.com/iB_html/non-cgi/emoticons/biggrin.gif" border="0" valign="absmiddle" alt=':D'>

I live on top of a hill on the foothills of the great Himalayas range, the house is brick and concrete affair but my neighbors wife always tells my wife that her windows rattle and shake and most of the times she knows when I am playing music or watching a movie.

abe

01-13-2004, 03:56 AM

Yamahaluver,   Does statistics show avalanches on Himalaya have been more frequent since you moved in?  ....

abe

Yamahaluver

01-13-2004, 08:06 AM

<table border="0" align="center" width="95%" cellpadding="0" cellspacing="0"><tr><td>abe : Yamahaluver, * Does statistics show avalanches on Himalaya have been more frequent since you moved in? *....

abe
<img src="http://www.audioholics.com/iB_html/non-cgi/emoticons/biggrin.gif" border="0" valign="absmiddle" alt=':D'>

Good one Abe, I would have to check with the seismic department but as long as they dont fall on my house.