Since many of us have been doing the FR graph and even waterfall chart, it is better for us to share it here .

Also, please share ways / ideas in taming the graph.

Pls also specify the room dimension, any acoustic treatment, etc (if possible)


Mine :

Room size : 10' x 20' (bad room size)
Minimal acoustic treatment with absorption panels and book shelf at the back as diffusor. No bass traps.

Previously



Sorry for the previous image



This post has been edited by htkaki: Sep 29 2009, 11:14 AM

what's the red and black line (before /after?)

Bro, how come there's a dip at the 48hz range? I believe svs eq1 can help even this out? Maybe you can post a graph pre and post audyssey MultiEQ (using ur denon) and pre and post SVS eq1.

If its not too time consuming Then it will give us laymen a better idea of the true power of ur beast

taiko, when ordering one?

Me no taikor la, young peasant onli hehehe...

Will order when my old one go out then new 1 come in haha...

yeah, old one dun go how new one can come (cantonese saying) hehe!

KNN this saying cannt be applied for HT or else forever be poor man leh haha

Here's the AS-EQ1 :

Impressive... is this the graph of your sub??

Also i am wondering if this is just before and after calibrating usign SVS eq1? No other calibration done? If yes, this gadget is working magic..

Jz done the AS-EQ1. I have yet to use 4310 to run Audyysey, which is recommended by most of the avs forummers.

Yes, it is indeed impressive. Here's the review :

http://www.audioholics.com/reviews/acousti...s-as-eq1-sub-eq

Thanks! Pls share with us the graph after u run with audyssey (Denon)... I'm still a bit skeptical to run audyssey on my onkyo

I posted this comparison sometime ago but was missed by many; so, I'll just re-post here for posterity

FR graph using REW to demonstrate the effect of my DIY corner bass trap.

1. All bass traps in place.


2. Remove Front Right corner bass trap.

Why are you skeptical? Got bad result before?

Set my fronts to -5 and set my sub to -15 ><

You only should be concerned if the setting is at the extreme ends (plus or minus).

In your case fronts at -5 dB is normal. Mine is at -7 dB. However, for your sub at -15 dB is at the extreme end. This indicates some kind of set up issue - simplest thing to try is decrease the volume control on the sub and rerun Audyssey.

Sub volume was at 25... Now i have set my sub reference level vol at 20-24... No prob at all.. I might give it another try and see as its quite time consuming and i spend more time calibrating it back to the way i like the sound to be....

When u rerun Audyssey just use the minimum 3 positions (to save time). This is just to see if it sets the sub trim higher than -15 dB.

OK will try it out during this weekend Pray pray that it doesnt screw it up again...

Actually this is the 2nd time that a Velo owner says that Audyssey sets the trims too low. I suspect its got something to do with the EQ that the Velo applies. I would need to spend some time to investigate this.

Appreciate that bro... 1 reason i suspect this could be bcos of the echo in the room causing audyssey to lower my velo trim to d max..

That goes to show how effective a bass trap is. Mind to show the bass trap. IIRC, it's a DIY, right?

Back to trim level, the AS-EQ1 calculated the distance and trim level, which I need to set it to my 4310. Trim is at -4dB.

During the Audyssey calibration, when the test tone is sent to your sub is it very loud? Normally the only reason why Audyssey would set the trim so much to -15 dB is if it thinks the test tone is too loud and it needs to compensate.

I didn't have any trouble with Audyssey with my previous Velo CHT-12Q. I recall Audyssey set the sub trim to -2 dB (and sub volume itself was at 30).

yes i recall that it was quite loud... But at that time i had no room accoustics, nothing... This could be the culprit..

the only way my audyssey trims my CHT12Q to +/- 2dB is if I set the gain at CHT-12Q to 10 only

I guess different AVR implements it slightly differently when it comes to levels. Either that or there is a lot of gain variance in the Velo subs

Bro, imagine what Audyssey will do to your submersive?? lol

Looking at your graph again, I think the limit of the EQ1's boost is around +10 dB, which is quite good. Some other devices might be limited to +6 dB or less.

Also, can you check with SVS if the EQ1 equalizes below 20 Hz? I notice the portion below 20 Hz looks about the same as the 'before'. Previously I did ask on AVS if MultEQ XT equalizes below 20 Hz but didn't get any definite answer.

i dunno.. i have no idea how 2 setup also & bro anfieldude is not in town to help me

guess i'll set the gain on sub to 33% and run Audyssey and live with the result until bro anfieldude gets back

Wow bro, hope you wont blow ur upstairs roof off lol since ur not able to tame this baby until anfieldude comes back

I suspect it could be the ugly room nodes since my room dimension s**ks (10' x 20'). But, I will also ask Ed abt the questions that you raised to double confirm

may i know u using wat equipment to measure that FR graph?
how much for that thing?

my Denon always give diff setting in dB for sub and speakers when re-run Audyssey. tried 3 times, all diff setting. its kinda hard to set mic at 6 constant position relative to listening area. i guess tis should be the reason behind..

Having different trim settings for speakers is quite common, nothing to worry about. It is not necessary to match the trim setting for your sub and speakers.

Your front speakers are likely different from your center and surround (maybe different brand, different impedance, different sensitivity). For your sub, a lot will depend on how loud you set the gain control on your sub.

from the graph 0 db reference level, flat curve... how many db SPL is that in real world loudness? got difference between 80db cheapo yammy sub and 110db like those JL and elite subs..

I think that depends on the loudness of the test tone sent by the EQ1. If I'm not mistaken the test tone is probably 75 - 85 dB.

That's why on many graphs you sometimes see a statement like "does not denote maximum output".

what we should know is how flat at how loud? Not just how flat at 80db. That seperates the pretenders fm the real deal.

The tone is set at 75dB

Here is my plot on Velo 12Q (AutoEQ done) with SR6003 (Audyssey done).

Using cheapo RS digital SPL with REW program. Level = 75dBC

Anyone know how to fine tune sub using SR6003 (i.e. EQ)?



Any sifu done FR on the main speakers? Too bad my RS SPL not accurate for high freq.

This post has been edited by gocitygo: Sep 29 2009, 08:27 PM

your chart looks quite good, the Auto EQ doing its job well.

my previous velo 10R also had sound levels falling off rapidly around 25-30Hz but the SVS can maintain sound levels well below 20Hz

Yes, I agree that it is more useful info to know what is the max loudness where a sub will maintain a flat graph. However, testing at 75-80dB is the industry standard.

Some time ago a new standard called CEA-2010 was introduced to test subs. You can read about it here: http://www.paragonhometheaters.com/news_info/tab4.htm This measures max clean output (as opposed to max flat output you mentioned). Unfortunately sub makers haven't adopted CEA-2010 when reporting performance specs.

wahlau! svs poision. the tot-kong is different category la.

me still new in HT. man-man lei, enjoy my investment.

one thing i learnt, better moderate or expensive gears, need to find way to optimize and unleash the full potential before jump into next upgrade. at least for me with hard earned $

i believe you are master in REW, me still blur blur and may get the master input

The graph is quite good considering that it is being done via Auto EQ and SR6003.

jchong,

I have got the answers :


Q1. The dip at 40Hz (must be room nodes) was being rectified to a certain extent; +10dB.

A1 : Yes, it's a room mode. Please try to move the listening position forward or rearward. This is an axial mode and you should be able to move out of it within 2-3 feet in either direction.



Q2: Is there a limit that the AS-EEQ1 can boost; like around 10 dB. Some other devices are very limited to below 6 dB or less.

A2 : Yes, there is a limit; it's 9 dB.


Q3: Does AS-EQ1 equalizes below 20 Hz? I notice the portion below 20 Hz looks about the same as the 'before'. If yes, then what could be the reason of this graph.

A3: Yes, the AS-EQ1 will equalize to 6 Hz with the current firmware/software. Make sure to set your room gain control to Bypass. Also make sure any THX Ultra II boundary gain compensation is set to off/no, and all your speakers are set to Small with 60 Hz for the mains, and 80 Hz for all others. Something else is causing a premature roll-off from 20-15 Hz. The subwoofer should be flat to 15 Hz before roll-off. Move the listening position and try it again.


On the above, I did wrongly set my speakers since the front is being set as full range (Large) and 40Hz for center and 60Hz for surr. Lesson learned

This post has been edited by htkaki: Sep 30 2009, 08:27 AM

AS-EQ1 really looks like a class act. I believe more so for people trying to equalize 2 subs..

I will do the calibration againto see how the new FR graph will look like. Hopefully that we can see a FR graph of 2 diff makes & models by Sunday.

sorry, maybe my reply not clear.
i meant when i run audyssey for 3 times, the setting for each and every speakers are not the same for 3 times.
for instance,

first run: center at +1.5db
second run: center at +1db
third run: center at -1.5db

so as for the rest of the speakers setting.
so everytime got some diff abt the surround effect that surrounding the listening area.

ps: audyssey eq actually quite sensitive, setting tat has been done if simply adjust manually again, then it might turn the audyssey off and need to redo the time consuming process again. quite fade up wif it.

Maybe the background noises were different each time you ran it.

Pretty close results. This was based on how many points (8 points). The reason u get slightly different results is due to different placement of mics each time. I believe the Audyssey mic is +/- 1dB and ur readings are close to that.

Don't worry too much abt it. Is the subwoofer trim also +/- 2dB. If yes, looks good and shd be ok. If u can check with a frequency response curve, it would be best.

perhaps

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Added on September 30, 2009, 6:32 pmmine low end 1, so 6 points only..
FL,FR,centre almost +/- 2-2.5db
sub forgotten, but it sets the distance to 7.5 meters away. in fact, only 2m++. but manual says normal since it has built in circuit that may cause tis
surr some time can get +3.5db, and it is rite abv sitting area.

how to check FR curve? wat equipment needed and price?

This post has been edited by cougar richard: Sep 30 2009, 06:32 PM

Check ur current post Audyssey sub trim and let me know. The distance for the sub not tallying with actual is ok. The sub generates the low frequencies. What Audyssey is doing by setting the distance setting further than the actual is in fact adding a delay to the sub so that all the frequencies arrive at ur ear (1st measurement position) at the same time. You probably have some parallel walls or something that are causing reflections from the subs to arrive at the primary seating position faster than the rest of the frequencies. Is the sub close to a wall?

How far off from actual are the distances of the fronts? What is the cutoffs that were applied for the fronts?

anfieldude, that means we should use the Audyssey sub distance rather than actual distance? for 5.1 level matching using SPL meter, should i use the Audyssey sub distance or actual sub distance from the listening position? still blur blur

I'm sorry, I don't understand ur question.

I would say use the Audyssey sub distance and not the actual sub distance.

Level matching ensure that at the listening position the speaker outputs are balanced and matched for output.

The distance setting is to calculate the delay that is to be added induced by room environment.

This is unusual. When I run Audyssey (using 3 positions for quick runs) the results are quite consistent from run to run.

Maybe as others have said, your ambient noise was different from run to run. Were your mic positions the same?

Me too
I used it for 6 positions, the results are quite consistent
btw, different height of mic for each position will affect the result also right?

Possibly. If you have a high back chair and your mic is lower than the back it can affect the results. In those cases you should set the mic higher than the back of the chair.

Otherwise generally the mic should be put at ear height.

I put it at ear height and done 32 positions (wt AS-EQ1)

anyone else measured their room response?

Hopefully to get mine done this weekend when Htkaki drops by with AS EQ 1:P

I posted Ron's room response in the subwoofer thread.

Hopefully, there will be more FR graphs in coming weeks, if you know what I mean

Anfieldude, I might send the AS-EQ1 to one of my cust in PG first for him to try out. Then, you guys turn to lay hands on it. Ok for you all?

Can anyone ajar how to read the graph?

a for apple
b for ball..

teach la

Bro, can post here to 'streamline' it adn easy for others to view?

Btw, EQ1 can do time domain.

wow, need to see how it can suppress those low frequency (10-30hz) response after 300ms which is clouding many sub's waterfall charts..

Actually, maybe gocitygo can post his charts here as well. I have seen his waterfall charts, Audyssey and room treatment, and it is awesome.

Ron's Submersive curves.
(with Ron's permission)

These are preliminary frequency curves that I took yesterday. I just took some basic measurements and it was done with the RS SPL Meter coz I forgot to bring my connector for the Galaxy CM-140. Will redo and play around with the crossovers to see if I can improve on this. Also this was all with Audyssey only and based on the curves I believe Ron can run the Audyssey again with the tripod for better results (since these results were based on Audyssey mic on the chair which is not correct)

1st chart : This is at reference 75dB. Pretty decent results. Room node of 31.5Hz present. Again need to check this post Audyssey again.


2nd chart : Ron's room is pretty difficult and probably needs to be redone after Audyssey. If still not able might need an AS-EQ1 one to improve on this. His lower frequencies barely settle down at 300ms. In fact they linger around for as long as 1s. In fact at 16Hz there is a pickup after 300ms that u cannot see. I believe I need to redo this with the Galaxy. I also believe this will improve after 2nd round of Audyssey. If this cannot be corrected, then a AS-EQ1 is necessary for further accuracy.


3rd chart: With the volume on AVR turned slightly up only, as I said, easily will hit 110dB with almost no distortion


Its a giant sub and if there is flexibility in placement I believe we could make it even better. Will post the new results once its done.

The EQ1 would be in PG after Deepavali. Eager to see the result.

htkaki,

He agreed or for someone else to test.....

If the customer keep it after the satisfying result, then I'll send another one up. Just for Ron and you to test it out.

This post has been edited by htkaki: Oct 8 2009, 07:56 PM

wah... htkaki so kind of u...

now poison by post...haha

based on the reviews, EQ1 will surely produce nearly flat FR; the only issue is whether you like the result or not...and of course, your

Np, bro. Just that I've a 'hidden agenda'

Dying to see the waterfall chart and the time domain correction that EQ1 is capable of. I don't have such equipment to do so at the moment. So, send to anfieldude and you would be ideal.

anfieldude, thanks for the compliment, paiseh paiseh. still got a lot to learn from all the sifus. compare to those tok kong sub and sub equalizer, just kacang nia.

i believe the room treatment helps a lot.



This post has been edited by gocitygo: Oct 10 2009, 11:54 AM

nice to see most of the bass died down by 300ms...

ar188,

Actually its all the bass gone by 300ms, floor noise is around 50Hz...

So I guess it is ideal to have all the bass gone by 300 ms?

If I'm reading correctly, there's still a touch of bass around at 300 ms at 20Hz, 24Hz, ~50Hz and ~60-70HZ but fairly low amplitude (60 dB and below). Am I reading correctly?

your chart looks good. mind sharing what you did - super bass traps??

bro ycs. no super bass trap la.

got 4 triangle traps at the top tri-corner, 3 rectangle traps at the wall-to-wall corner, 1 rectangle trap at the back listening position and 2 rectangle traps at the side of main front speakers. trap material = 1" thick rockwool (80 kg/m3 density).

plenty of foam traps the wall-to-wall corner. i believe yours no less that me.

next, plan to DIY the diffusor recommended by you .

Correct, the amplitude of 50-60dB shd be floor noise and is acceptable.

how do we measure floor noise?

sorry for noob question.

This post has been edited by gocitygo: Oct 10 2009, 06:17 PM

Is this floor noise quite prevalent in all homes/rooms?

Measure ur room noise without any sound playing with the SPL meter.

No it depends on ur own environment. If ur room is quite well soundproofed, then it could be lower.

In my case, during the day, it is around 55dB. At night shd be less. Also if u have the air con on during measurement, then u shd measure the floor noise with it to understand the effect of it.

Yerp, just like anfielddude said, floor noise differs, typical living room would be around 50dB-60dB, got that in my room too.

I see. I did measure my room using the CM140. At night, when there is little external noise it is about 40-41 dB (this is everything turned off).

wow, 40dB is quite low. the next thing you will find the aircond quite noisy, he he

btw, is CM140 goods until 20kHz? then, you can measure the front speaker liao.

This post has been edited by gocitygo: Oct 10 2009, 09:24 PM

Yeah, the air-con is now the weak point in terms of noise

According to specs, the CM140 is good up to 8kHz.

Sorry for the noob question. For the yammy 665, lowest manual GEQ is 63hz. But in the absence of lower GEQ, only way to correct the response would be room correction or purchase of svs - EQ1? Or buy an AVR with better GEQ? How low does Audessey allow to adjust?

Audyssey does not allow manual adjustment of the EQ. So you will not see any equalizer bands for Audyssey that are user selectable.

However, I understand that Audyssey can adjust down to 20Hz (or maybe even lower).

No AVR with better GEQ would allow you to manually equalise that low.I don't think AUdyssey ESq1 allows manual adjustment(correct me if I'm wrong), try sms1 or behringer if you would like to tweak the values manually.

Tks. Alternative to tat method would be like gocitygo and get an auto eq sub, e.g Velo CHT-10/12Q? Which so far from his graphs are impressive.

OT a bit, 665 GEQ also has quite a large gap between 2.5khz and 6.3khz and straight to 16khz. Am having problems solving spikes above 5khz from all speakers, which is obvious when running linear sweep test tones from REW. Would sifus know how to tame/correct those spikes or am using the wrong tones to test?

Can u post ur charts and how u took the measurements? I'm curious. Also the RS SPL Meter is not known to be accurate past 5kHz.

---

Added on October 10, 2009, 11:12 pmCM140 is spec'ed to 8KHz but its calibrated at the factory and tests comparing to a calibrated mic have shown accuracy up till 20kHz.

This post has been edited by anfieldude: Oct 10 2009, 11:12 PM

gocitygo's response is good due to a couple of things, room treatment and Audyssey.

Yammy's YPAO is generally not as highly regarded as Audyssey.

I think RS performs crappy-ly at sub range.. that's why have to put so much weighing correction..

these things are more good for measuring relative loudness between speakers (when doing room correction/calibration between main/surround speakers) rather than getting accurate SPL readings of individual speakers....

---

Added on October 11, 2009, 12:00 amthat's what I meant..

the floor is already set as 48dB from the Y axis of the graph.. (not at 0db) so when I said most of the bass has died down (meaning except 45,50 and 65hz) , it means just that.. most of it reached the noise floor i,e, 48db



This post has been edited by ar188: Oct 11 2009, 12:00 AM

Yeah, peasant here on both counts .

Measurements were just read off the meter as the linear sweep was played between 63hz to 17khz at 75dB for each channel. Was fluctuation between plus/minus 2dB up until 5khz when it went off the analog meter first above 80dB and later below 70dB around 9khz. Roughly the same response for the wideband pink noise played for each channel on the Avia II disc but not sure of the frequencies on those track as not stated.

Havent hookup the SPL meter to the soundcard yet, will try to do so soon.

Excellent!