My SVS 16-46 has FINALLY impressed me! (1 Viewer)

[Tom Vodhanel]

>>>TV, when do we get to see that PB2!!

 

[Tom Vodhanel]

Hi Mitch,


>>>Well no. See, I downloaded the PEQ ver 1.05 (Excel Spreadsheet available online, along with the mp3s to go with it). Anyway, it has the colums already there...All I did was input the "raw dB" that I got from the Radio Shack meter, and it did the correcting in the 3rd colum. I didn't do any of the corrections myself. I guess that the equations on the spreadsheet must be wrong.>Thanks, but I don't know how to build my own sub. I have absolutely no knowledge what-so-ever of any of this.
I'm hoping that I can get my old room back...I'm sure that the SVS would be more than enough in there. My old room had hard wood floors. It was 13 x 16. My parents have my old room, but maybe I could switch rooms with them.
I really love the look of the SVS, and I don't want to part with it. Like I said before, maybe I'll add a B-4 in addition to this one, in the future.

 

[Nick P]

Jeff, I don't think anyone attacked SVS or Ron. I'm fairly certain most of the comments were meant in good fun.

Yeah, what Keith said. I'm a proud owner of a twin 20-39CS+ S1000 combo. I just thought it was kinda funny for Ron's sig to say what it said.

 

[Mike Matheson]

Mitch,

Here are the standard RS meter corrections:

Hz correction
10 20.0
12.5 16.0
16 11.5
20 7.5
25 5.0
31 3.0
40 2.5
50 1.5
63 1.5
80 1.5
100 2.0
125 0.5
160 -0.5
200 -0.5
250 0.5
315 -0.5
400 0.0

Maybe you could delete the columns your spreadsheet following your raw readings, and create a new column with the correction to be applied, and then another new column with the corrected value. Add your raw value and correction and then post these updated corrected values. (Like TV mentioned, the numbers you've give, for whatever reason, seem WAY off).

 

[Mike Matheson]

TV,

Any chance of a B-2 rather than a PB-2? (I've got an amp already)

 

[Mitch Stevens]

Thanks Mike.

I'm going to redo this entire test with all of my speaker turned off (especially my center).

 

[Mitch Stevens]

Ok. Here the re-done results, with absolutely no interference of frequencies what-so-ever. I had all speakers disconnected except for the SVS. I did the correct RS meter corrections:

Freq/raw db/Corr.
10.65069
11.25169
11.95168
12.65470.5
13.35570
14.16175
15.06477
15.86778.5
16.86979.5
17.87080
18.86775.5
20.06875.5
21.16975.5
22.47076
23.77075.5
25.16974
26.66771.5
28.26569
29.96568.5
31.66366
33.56466.85
35.56668.75
37.67072.75
39.87173.5
42.27173.4
44.77072
47.36566.75
50.17172.5
53.17677.5
56.28283.5
59.68283.5
63.18283.5
66.88182.5
70.87980.5
75.07677.5
79.47475.5
84.17576.5
89.17475.75
94.47071.8
100.7072

*I started with the 100hz tone at 70dB, and went down from there.

 

[Zack_R]

Here's my armchair analysis.

Overall I'd say that's pretty good. 14 to 25 hz looks excellent. Since your ears are less sensitive at those frequencies having a bunmp through there is good imo.

26-35 is a little weak when compared to 37-53. 37-53 gets back on track (except 47 hz)

56-70 gets you a little on the hot side and could make it sound a little boomy.

This is a nice detailed look at your frequencies but it's a little on the micro-management side. You could take the frequencies you posted and get a block average. For example, starting at 20 add the next 8 or so frequencies and divide by nine to get an average for that block of sound frequencies. Then take the next 8 to 9 frequencies get an average, and so on until you get to 80 hz. Bass in music, typically is going to cover a boad range of frequencies and won't usually dwell on one or two frequencies.

Now my opinion on what to do.

You should run your left and right main speakers in the test as I don't forsee you listening to sub only music. This may change the landscape of your graph since you'll have to contend with bass cancellation or bass augmentation.

Beyond that adding an equalizer could help tame your peaks around the low range (26-35. Except for real low organ music, not much other bass in music is going to play in that range, so if it was me I wouldn't bother with it. In movies the LFE will be boosted anyway and I don't think you would be able to notice that it's lower than other frequencies. The good news is you have a sub that can play all the freuencies as there appears to be no huge cliff where the bass falls off and can't recover.

 

[Dan Lindley]

I was joking too (not clear re Gateway/Dell or Gates/WP?).

I wouldn't impose taste on anyone, but I surely believe Ron and Tom and SVS are doing what they can to bring out great product at a good price. They seem to like what they are doing, and I bet most people who questioned the sig either thought it was funny or puzzling. Or both.

d

 

[Mitch Stevens]

Zack,

Here are the results of the speakers with the SVS. I'm getting some serious cancellation at 100hz. I could not get that frequency to play loud, no matter how high I put it. When I had just the SVS on all by itself, I was quickly able to achieve that frequency, but with all my speaker on, I can't.

So, because of that, I had to start 100hz at 60dB:

Freq/raw db/Corr.
10.05575
10.65574
11.25573
11.95471
12.65571.5
13.35772
14.15872
15.05972
15.86071.5
16.86070.5
17.86171
18.86270.5
20.06269.5
21.16470.5
22.46470
23.76671.5
25.16873
26.66973.5
28.26973
29.97073.5
31.67174
33.57173.85
35.57274.75
37.67577.75
39.87880.5
42.27880.4
44.78082
47.37778.75
50.18182.5
53.18384.5
56.28788.5
59.68182.5
63.18182.5
66.87475.5
70.86970.5
75.06667.5
79.47172.5
84.17172.5
89.16970.75
94.47677.8
100.6062

 

[Zack_R]

Okay,

I had a similar situation myself. 100 hz played weak for me and I suspect you've got some cancellation. Your problem area appears to be 68-100 hz with the exception of that 94.4 reading.

Try this.

Set your crossover to 80 (or whatever your receiver sets the crossover to) on the receiver and take the SVS crossover up as far as it goes to get it out of the way. If you don't have this setting on your receiver then set the SVS to 80hz. With the sub on take the same test with the balance nob turned to your left speaker and record the results. Then do the same with the balance nob turned to your right speaker and record the results. Ensure you have the microphone in the exact same place for each side when you do the two two test. If you get different results from the left side to the right side then the weaker side is the side that is cancelling your sound. If your situation is like mine then the speaker closes to the SVS will be the culprit.

Now do the test with the phase at 180 deg. Play the test through the weak side. Note any improvements. Perform the test again by putting the phase at 120 then 60. The attempt hear would be to dial in the loudest response at a given phase seting so an optimal setting may be somewhere in between.

If you can achieve an improvement then run the test again with the balance nob in the center position to see what happens with the left, right and sub play the test with your phase at it's most powerful postion.


I used the avia sub set-up calibration to fix my problem. If you have Avia play the left speaker and then record the first 2 phase burst for the sub to get an average. Then skip to the right speaker track and record the same two phase burst through the sub. When I did this I got a much lower db response from my right speaker to sub output than my left speaker to sub output. Not only were the db readings lower but it was very audiblly noticeable. I reversed the phase and like magic both sides now had near identical output responses.

Hopefully one of these two techniques can help you identify and then fix your cancellation problem.


Good Luck!

 

[Tom Vodhanel]

Hi Mitch,

Have you had a chance to follow Zack's excellent advice yet? The sub/speakers are definitely working against each other near the XO point...luckily that problem is(usually) easily tamed.

Tom V.
SVS

 

[Mitch Stevens]

Ok.

Hi Tom, yes...I did exactly what he said, and it worked!

Zack...Thank you SO much for being so helpful and kind. Here are the results I got now:

Freq/raw db/Corr.
10.05575
10.65473
11.25371
11.95269
12.65369.5
13.35368
14.15468
15.05770
15.85869.5
16.86171.5
17.86171
18.86371.5
20.06269.5
21.16470.5
22.46470
23.76671.5
25.16671
26.66569.5
28.26468
29.96770.5
31.66770
33.56870.85
35.57173.75
37.67375.75
39.87375.5
42.26870.4
44.77274
47.36465.75
50.17475.5
53.17879.5
56.28384.5
59.68485.5
63.18485.5
66.88384.5
70.88081.5
75.07576.5
79.47374.5
84.17576.5
89.17374.75
94.47677.8
100.7072

Is this good enough, or can other things be done now?

 

[Zack_R]

Do you like the way it sounds? From your numbers, bass in normal music looks like it should sound fuller than before. You may find that the bass volume is a little to loud now and would need to turn down the SVS volume a few clicks. But more on that later.

It seems like you've got a pretty good handle on how to tweak your phase setting. I'm curious as to what phase setting you ended up with?

From this point I would recommend geting Avia or Video Essentials (if you don't have one yet) becuase you will want to balance your sub with your mains. Avia will play a phase tone that is centered above the sub so your main speaker mostly plays the sound. Avia then generates a low bass phase note that will primarily be played by the sub. The objective being to adjust volume levels so that (for example)the left main speaker is equal from an spl level standpoint to the sub. I know you have a large room but if you get your sub dialed in so that is level matched to your system, I think you'll be suprised at how loud it will go. Keep in mind that not all songs have good bass or bass that extends low. Experiment with a variety of music types and you will quickly see or hear the differences you've been missing before.

If you have not done something like this then you are probably running your sub at spl levels that are greater and therefore not in balance with other non-bass sounds produced by your mains.

As for what to do next. Well thats up to you since there is only so much more you can do without some sort of eq and maybe room treatments. Most everyone with a sub has these issues so it can becomes a compromise of sorts to get the absolute flattest response to your seating postion. Personnaly, I concentrate on 1/3 octaves or a *range of sound freq.* to achieve a smooth response. There will likely always be the oddball freq or two that will put a peak or dip in the freq. range but overall bass in music is compirsed of a large range of bass sounds not one or two frequencies. This how something that starts out simple can turn into a hobby.

I copied and pasted part of your last test that may be worth trying to tweak a little more. Just keep in mind that probably all of this is related to your room and seating position and the not the 16-46. The trick here is to try and lower the range I pasted below, without lowering the range above or below by the same amount. Meaning you may luck out and lower your SVS volume knob a few clicks and it would lower your whole bass range but if it was to lower the range I pasted below greater than the range above or below, then this would be good. The goal is to reduce the db distannce between the peak areas and the low areas. If you could get that 53-70 range into the mid seventies without altering your other frequencies too much I think you'd like the sound it will produce for you.

If you graphed your numbers (trend line) you may find it more visually impactful when looking for problem areas as well as comparing one test run to another.

You can keep experimenting with sub placement to improve room response furher. If you like the sub where it is and want more improvements than what you are able to achieve with the phase and volume setting controls you may want to look into getting an eq.


53.1 78 79.5
56.2 83 84.5
59.6 84 85.5
63.1 84 85.5
66.8 83 84.5
70.8 80 81.5

 

[Scott MacKay]

Zack_R

Is it possible to use the test you posted above about phase without using a microphone? I only have the RS spl meter. I do own a Avia disk but I find adjusting the phase while watching the meter difficult. Any suggestions on music? Thanks


Scott

 

[Zack_R]

Scott,

Actually what you have is all that I used to get my sub in the ballpark for phase. What I did and what you can try is simply to use the 5.1 speaker set-up in Avia. What you'll want to do is listen to the left-front-sub phase and then the right-front-sub phase. Just skip over the center portion. I would only use the first two sub phase burst with Avia for each side.

Just set your volume on the receiver so that the left phase is registering 70 dbs or so at you seat. At this point all we are trying to accomplish is getting a good left-sub/right-sub phase balance so it's no need to blast 85 dbs worth of pink noise unless you want to. You'll aslo want to make sure you are using your receivers cross-over so disable the sub crossover or move it as high as it will go. If your receiver let's you, select an 80 hz crossover point or one that is closest to 80hz.

Without even looking at the spl meter it was audible to my ears that I had a severe cancellation with my right front sub test as it was very attentuated compared to the left-sub test. If your ears can't tell you then just look at the spl meter to see if there is much difference in db between the left and right sub test phases. Mine was so weak on the right that I thought the guys at Avia didn't record the damn sound right. Little did I know I had and still have a lot to learn.

Assuming the sub output sounds quieter on (for example) the right side, it's time to start adjusting the phase. What you will want to do is put the phase at 180 deg first then remeasure the left and right test. Then I would move the phase to 120 and do the left and right test. Let's say 180 was an improvement and 120 was less of an improvement. From here put the phase at 150 and retest. Keep doing this until you get the right side sub phase in line with the left side sub phase or produce the loudest equal db measurement from both the left and the right.

I have read that the Avia sub pink noise portion is actually a combination of low bass that ranges from 30-70 hz. This is the reason I suggest only using the first two phase burst. It seems that the third and fourth and a couple near the end always produce a little more reading on my spl meter so for simplicity sake just use the first one or two phase burst.

If you happen to use a center speaker that's very substantial in the bass department you may want to include it in the test at some point but for now I would concentrate on obtaining a good phase balance with you two main speakers.

This technique should get you in pretty good phase alignment. However, this doesn't mean your actual frequency response is flat. So if you were to play individual test tones or say the LFE sweep you will likely gets some peaks and valleys.

It's these peaks and valleys where you decide how serious you want this hobby to be. You could try moving the sub a little or get an eq or the BFD that many on this forum use to soomth out bass response. To do this you will likely want the microphone, computer or very narrow individual test tones that you could record and graph manually to paper.

 

[Scott MacKay]

Thanks Zack!! All this time I have been trying to increase the spl within one test section- for example, I would listen to the left center-sub phase test for a rise in spl while adjusting the phase knob.

Scott

 

[Yee-Ming]

*heh*

I finally got a Ratshack SPL meter to calibrate my setup. after running Avia briefly, it appeared that my sub was a bit too hot, by around 5dBs. so I dialled it back to just 2-3dBs hot, but didn't like the result and cranked it back up.

upon reading this thread, I now realise that I'd forgotten about compensating for the inaccuracy of the meter at low frequencies, so I guess I was right on the money all along. and my intial "calibration" was by ear only, running Avia and then movies and music "to taste".

not bad, if I do say so myself

as for the other speakers, the centre was "hot" by 1 dB, but that was deliberate anyway since I wanted dialogue clearer when I was watching some old material with poor sources, and one of the surrounds was also "hot" by 1dB. not too shabby...

 

[Ben Jordan]

But the correction chart for the RS meter shows that it reads less, not more, for those low frequencies. If the meter showed your sub as +5 hot, it was actually a lot hotter than that.

 

[Tom Vodhanel]

Hi Yee-Ming and Ben,


Yup, if the RS meter read 5dB hot at 25hz...than that would be about 10dB hot actual...

Avia (and VE)uses a 40-80hz bandwidth on the bass calibration tone, so I would add about 2dBs to the RS meter's readout when using either one for calibrating.

Mitch, I see things are working out much better for you now, Zack seems to know his stuff...so keep listening...but I am going to remeasure the AVIA test tones soon, just to see if they are 30-70 or 40-80hz..

Tom V.
SVS