Calibrate sub, Please help newbie

[alpharetta]

Good morning everyone,

I am reading "Subwoofer Calibration using Rives Audio Test CD 2 " http://www.audioholics.com/techtips/setup/loudspeakers/subwoofercalibration.php and have couple questions. Please advice me, a newbie loves to have good bass in HT.

1. Jeff Lawson mentioned that we need to have EQ for Subwoofer Calibration. Where should I find it, and what is good one in the term of Quality and resonable price. I appreciate if you could provide detail information or links. Someone told me that I have Yamaha 2500 receiver, which has the EQ already .. but I am not sure about it.

2. Radio Shack Analog Sound Level Meter. I only see Digital Sound level Meter from Radio shack. Is it OK to buy digital meter? Since rives audio test Cd2 has tones compensated for the response of the Radio Shack analog SPL meter, I am not sure if switch to Digital meter, the Rives test CD is still good to go?

3. Should I have both AVIA and Digital Video Essentials disks or one of them is enough?

Many thanks and you have a wonderful weekend

Alpharetta

 

[jaxvon]

1. For good EQ, opt for either a Behringer Feedback Destroyer or Behringer DCX2496.

2. Not sure on digital vs. analog. But if you need the analog SPL meter, you can get it here.

3. Some reading: http://forums.audioholics.com/forums/showthread.php?t=12043&highlight=AVIA

 

[alpharetta]

SPL meter - digital vs analog?

Many thanks Jaxvon for the information.

I bought both AVIA and Digital Video Essentials disks on ebay today since each of them has pros and cons, one is good for Audio calibration, other is detail in Video calibration.

Regarding the EQ, I think I will try to calibrate without it first. If not successful, I will get one.

I am still not sure i should get digital or analog RadioShack SPL meter. One of mine friends told me that he wish he could buy the digital one because it's easy to read. However, I am a newbie, and I want to do "by the book" as in "Subwoofer Calibration using Rives Audio Test CD 2" by Jeff Lawson.

If anyone has opinion on the SPL meter, please advice.

Thanks

 

[jaxvon]

Well, this is unrelated, but judging from your sig, you're quite happy with your system. If you're a rock fan at all, I suggest that you pick up the In Absentia DVD-A from Porcupine Tree. While it doesn't have the ultimate fidelity of a Mapleshade or Telarc CD, its surround implementation is AMAZING. Crank it up and sit back.

http://www.amazon.com/exec/obidos/tg/detail/-/B00016POFE/qid=1131337091/sr=8-2/ref=pd_bbs_2/104-5333420-0520738?v=glance&s=music&n=507846

 

[MACCA350]

Thought I'd drop this in, Velodyne have just released a new 'Subwoofer Management System'(SMS-1) which gives Digital Eq capabilility similar to the Digital Drive Series subs.

cheers

 

[mike c]

do you know how much the velodyne thing retails?

 

[GregBe]

The Velodyne retails for $699, but has a street price of $599. As far as sub eq goes, I think before you invest in an eq, you want to figure out what your sub is doing without it. It is very room dependant. Some rooms affect subs in the worst way, and an eq will make a dramatic difference. In other rooms, you can get a pretty flat response without one, and the difference may not be dramatic enough to warrant the purchase.

BTW, I have the EP500 as well (just got it). It is pretty incredible. I am in the same boat you are in. I am trying to figure out whether or not I want to purchase an SMS-1. Hopefully, I will be able to plot out my room response this week sometime.

Greg

 

[mike c]

wow, thats more expensive than my sub!

 

[alpharetta]

Posting an update

Well. I would like to post an update with my progress...
I got "AVIA Guide to Home Theater" delivered today. It's amazing fast. I bought it on ebay on Saturday. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=6447947159 it 's cheaper Amazon price.. I did not find much useful information from the disc since I know most of them already.

However, AVIA disc answers me one question: digital spl meter or analog? It says that for the audio calibration purpose, analog is the useful one better than digital. I ran to RadioShack and bought the analog meter. I also had chance to see the digital meter at Radio shack. the interface of digital is quite different than the analog. I am glad that I got the analog one, so I could use it accordinly to "Subwoofer Calibration using Rives Audio Test CD 2" by Jeff Lawson. Other good news that the analog meter is cheaper than digital for $10.

Now I am waiting for Rives Audio Test CD delivered. I could not find this disk anywhere on NET, but Rives website. It cost $21 plus $4 shipping.

 

[jcPanny]

Rocket Digital EQ

Av123.com ha a multiband PEQ for subwoofers for about $400. You can get a lower price if you have previously purchased from them. However, they are currently sold out.
http://www.av123.com/products_product.php?section=processors&product=31.1

Also, you might email Axiom. Since their sub is DSP based and has a USB for updates, they might be planning to add an EQ function in the future.

 

[GregBe]

Also, you might email Axiom. Since their sub is DSP based and has a USB for updates, they might be planning to add an EQ function in the future.

Good thought JC, but I asked Axiom that same question when I bought my EP500. They have no immediate plans for an eq.

 

[JeffD2.]

Do not use DVE for sub calibration. I've read about AND tried it. It just doesn't work anywhere as good for sub calibration. It apparently has a 10dB error which has been acknowledged by the author or so I've read. It does a better job than Avia for video calibration however.

In summary-
Use DVE for video calibration.
Use Avia for audio calibration.
UNLESS you get Avia Pro, which you can use for both.

IMO, an EQ for the sub is not an IMMEDIATE requirement. You have to experiment with optimal sub placement first, then address room peaks with an EQ.

 

[alpharetta]

Update: No bass from 40hz to 80 hz - help

I would like to give you some update and need your advice.

I got Rives Test CD and RadioShack Analog meter. My sub does not produce bass from 40hz to 80 hz, eventhough bass is very good from 25 hz to 40 hz.
I know it may be the room environment, but when I put my ears in the front and next the sub, I just barelly hear a littly tiny death bass, almost zero.
No wonder why my friend said that my sound system is not good at bass whey play music, because they don't hear any...

I concern a lot right now. I am afraid that my sub has some bug or issue. I set cross over 80 hz in my receiver and all speakers are small.

Couple questions need your advice:

1. I have Denon 2910 dvd player, should I use 5.1 outputs hook up to multi - input of my Yamaha rx-v2500 and use pure direct?

2. I also have "Surround Test CD" http://www.cduniverse.com/search/xx/music/pid/1237280/a/Dolby+Surround+Test.htm, what program i should set on my receiver to test the bass performance? Surround, movie, THX, or stereo.

3. I am thinking to take the sub out to the back yard to make sure that there is no restriction on environment, just to make sure that the sub is actually working well. Is it a good idea? I asked AXiom, but they just give me bunch of links, ask me to read. And they said it's waste time to do the sub testing in back yard.

Please advice. Many thanks Guys.

 

[s002wjh]

I guess you follow all the instruction in this site on how to setup sub etc. btw whats db you have around those freq? I'm also new at this, but I learn alot more about sub at avsforum.com, they have some serious expert in there. http://www.avsforum.com/avs-vb/forumdisplay.php?s=&daysprune=30&f=113 just ask them your question i'm sure someone will give you some suggestions.

also make sure follow the axiom sub manual on setup etc. when use digital coax /optical from dvd to receiver should be fine. maybe check the manual on your receiver. i basicaly use bypass, line-in, and flat for that sub.

 

[s002wjh]

i found the manual for svs subwoofer is really helful. although is for different sub, but the setup is pretty much same you can check it out, and use the info you found to calibrate. http://www.svsubwoofers.com/manuals/pb12ultra2_plus2.pdf

 

[jcPanny]

Axiom sub DSP

I read something in a subwoofer shoutout including the Axiom EP500 that it has some noise rejection capabilities built into its DSP. Since the sub is expecting a varying audio signal, when it sees a constant 60 Hz, it thinks it is noise from the 120V AC / 60 Hz power line and attenuates that frequency. It sounds like this is attenuating the test tones in that range.

Axiom has great customer support. I would email them about this "feature" and ask if there is a way to bypass it for calibration purposes.

 

[GregBe]

What do you have your sub's crossover set at. If you have it at 80hz in your receiver, you want to set the Axiom crossover to bypass. If you have the crossover on the sub turned down to 40hz, that would explain the lack of response between 40 and 80.

I do agree that I would call Axiom.

 

[alpharetta]

Cross Over

What do you have your sub's crossover set at. If you have it at 80hz in your receiver, you want to set the Axiom crossover to bypass. If you have the crossover on the sub turned down to 40hz, that would explain the lack of response between 40 and 80.

I do agree that I would call Axiom.

Yes, I do set cross over 80 hz in the receiver, and by pass in the sub. No result so far. I look into User Guide of Axiom Sub, it's very plain compare to the informative and useful user guide of SVS sub

 

[s002wjh]

not sure maybe the guys at avs forum knows. meantime read the receiver manual and DVD player manual, maybe set on dts or dolby mode cause the sub not put out any bass when play music, I'm not expert, but do read the manual. also use the avia or your surround cd that you bought to test the frequency from 40-80hz see if that work, follow the instruction in svs manual. if you got bass at that freq. range then its probably your setup is wrong. here is another manual from rocket sub, its kind same thing as SVS sub manual, but you might find something in there.

http://www.av123.com/manuals/1_Rocket UFW-10 OMAN_v1.pdf

 

[alpharetta]

Weak bass out from sub woofer output - Yamama v2500

Update as of today:

I was thinking that something goes wrong with my sub, so I decided to test the performance of the sub standalone: I bought an external audio card hook up to my laptop via usb port. This audio card is made by Creative Sound Blaster. It has optical ouput, and stereo outputs (white and red). the audio card is power by the usb, so the output is similar to pre-amp output from the receiver. I hook up the stereo ouput (the Red one) to the sub, and started testing the sub alone using surround test CD. The track 47 to track 67 in this CD produce the sound with frequency 120 hz down to 10 hz. The sub performed very well from 120 hz to 25 hz. Well I don't expect it sounds lower than 25 hz because that's what its spec says.

With this test I know for sure that the sub is OK. Now I need to figure out what's wrong with combination receiver + sub. I hook up the sub to the receiver via sub cable (like rca cable). I set different cross over, select different program like stereo, surround, movie ... However I hardly recognize the sound from the sub. I turn off all other speaker, and only to listen very tinny sound from sub when I put my ears next to the sub grill.

I tried to boost sub level via receiver interface, not much improvement. One interesting thing is that when I use the Auto Test feature of the receiver, the test says my sub is OK, and adjust sub level down to -10. When the Auto test going, I heard the sound from the sub very well.

What it could be? Please help. I cross my fingure that there is nothing wrong with my receiver, but just the way I set my system...

Thanks and Happy thanks Giving.
Alpharetta