# Graph of my 2 subs?



## Bloodta (Sep 15, 2014)

How does this graph look of my 2 sub placement? I'm not real sure what to look for.


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## jcmusic (Oct 26, 2012)

I could be wrong but, I have never seen a curve that looks that smooth without smoothing unless you have about 50 bass traps in the room...


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## randyc1 (Jul 20, 2011)

Set Hz limits from 0-100Hz


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## Phillips (Aug 12, 2011)

Bloodta said:


> How does this graph look of my 2 sub placement? I'm not real sure what to look for.


Where are they placed?

Try flipping the phase,polarity to see if it improves.

Please list the subs.


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## Bloodta (Sep 15, 2014)

Phillips said:


> Where are they placed?
> 
> Try flipping the phase,polarity to see if it improves.
> 
> Please list the subs.


So this is a bad graph? The subs are PA-120s. One is to the right of my front left speaker the other is in the back left corner.


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## Phillips (Aug 12, 2011)

Bloodta said:


> So this is a bad graph? The subs are PA-120s. One is to the right of my front left speaker the other is in the back left corner.


When running two subs they need to playing together not fighting each other, this can cause dips etc.

If you don't have phase / polarity then try moving to maybe flatten the response.

Try in the middle of the walls, e.g. middle of front wall and rear wall.

Do you intend to use EQ?

This isn't necessarily a bad graph but could be improved on, specially running two subs, actually careful setup properly can avoid EQ.


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## Bloodta (Sep 15, 2014)

Phillips said:


> When running two subs they need to playing together not fighting each other, this can cause dips etc.
> 
> If you don't have phase / polarity then try moving to maybe flatten the response.
> 
> ...


This is with EQ and my knee-curve. Dark gold is before EQ, light gold is with EQ


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## Phillips (Aug 12, 2011)

Bloodta said:


> This is with EQ and my knee-curve. Dark gold is before EQ, light gold is with EQ


The first graph in post 1 was no EQ, this is what you should be going off.
Less for the EQ to deal with the better.

What does the Waterfall graph look like?

Your last graph is only prediction not actual. Re- measure to confirm this is your actual measurement.

Try without EQ what I suggested in my previous post phase / polarity etc.

In theory with two subs the extension should be better and smoother. Make sure the volume of each sub is the same at the listening position.

If you have the .mdat file of both subs measured separately and together post this.


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## Bloodta (Sep 15, 2014)

Phillips said:


> The first graph in post 1 was no EQ, this is what you should be going off.
> Less for the EQ to deal with the better.
> 
> What does the Waterfall graph look like?
> ...


Here's a graph, the dark red with a big dip is one of my first measurements with the subs on the left and right walls, about 1/3 way down. Blue is where they are now, before EQ. Gold is where they are before EQ, with the phase set the same on both subs. Purple is now with EQ and phase on rear sub at 180, and front sub phase at 0.


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## Phillips (Aug 12, 2011)

Bloodta said:


> Here's a graph, the dark red with a big dip is one of my first measurements with the subs on the left and right walls, about 1/3 way down. Blue is where they are now, before EQ. Gold is where they are before EQ, with the phase set the same on both subs. Purple is now with EQ and phase on rear sub at 180, and front sub phase at 0.


Move around the subs more, try middle of opposite walls e.g. front and back even try in each front corners, one in left front corner and one in rear right corner. There is a lot be gained by doing this at the start specially if you have no restrictions on placement. 

Keep on measuring the subs only. 

Post the .mdat files of what you have currently.


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## Bloodta (Sep 15, 2014)

Phillips said:


> Move around the subs more, try middle of opposite walls e.g. front and back even try in each front corners, one in left front corner and one in rear right corner. There is a lot be gained by doing this at the start specially if you have no restrictions on placement.
> 
> Keep on measuring the subs only.
> 
> Post the .mdat files of what you have currently.


The subs are in the best place available after some measurements. Here's my .mdat file. Your feedback is appreciated.


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## Phillips (Aug 12, 2011)

Number 11 and 13 look fine. Waterfall graph looks ok

Can you measure the subs individually at the listening position and name accordingly e.g. Sub 1,0 phase (and position) Sub 2, 0 phase (and position). Just want to check something.

Please list your gear amp etc.


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## Bloodta (Sep 15, 2014)

Phillips said:


> Number 11 and 13 look fine. Waterfall graph looks ok
> 
> Can you measure the subs individually at the listening position and name accordingly e.g. Sub 1,0 phase (and position) Sub 2, 0 phase (and position). Just want to check something.
> 
> Please list your gear amp etc.


Ok, I can do that sometime this week. I have 2 PA-120 subs, and an Onkyo 805 receiver. Also, I'm very new to this stuff, can you tell me what you're looking for? Thanks


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## Phillips (Aug 12, 2011)

Bloodta said:


> Ok, I can do that sometime this week. I have 2 PA-120 subs, and an Onkyo 805 receiver. Also, I'm very new to this stuff, can you tell me what you're looking for? Thanks


Ok no worries.

Make sure you measure with no EQ, forgot to tell you.

Mainly looking at polarity.

Was 11 and 13 with or without EQ?

Does your Onkyo EQ subs? Which EQ do you use for EQing.

The latest receivers are generally good at setting level, distance (delay).

The main thing is to get the subs + speakers in the best position possible first to give the EQ least as possible to fix.


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## Bloodta (Sep 15, 2014)

Phillips said:


> Ok no worries.
> 
> Make sure you measure with no EQ, forgot to tell you.
> 
> ...


11 and 13 are with EQ from a Feedback Destroyer Pro 1124, the measurements were done from the subs not through the Onkyo (connected the laptop directly to the subs). I assume once I get the subs dialed in with the Feedback Destroyer, ill need to run Audessy again.


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## Phillips (Aug 12, 2011)

11 and 13 look ok just to make sure. 

As long as there were not too many filters large boosts etc made. The idea is to get the flattest lowest decay (waterfall graph) from your dual subs then apply minimal EQ.

Also measure main speakers individually and then together, this applies to subs as well.

Are you running dual subs as mono or stereo?


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## Bloodta (Sep 15, 2014)

Phillips said:


> Number 11 and 13 look fine. Waterfall graph looks ok
> 
> Can you measure the subs individually at the listening position and name accordingly e.g. Sub 1,0 phase (and position) Sub 2, 0 phase (and position). Just want to check something.
> 
> Please list your gear amp etc.


Heres the .mdat file of the measurements you asked for, plus a few extra. I left notes in each measurement.


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## Phillips (Aug 12, 2011)

Is this the sub, link below?

http://www.premieracoustic.com/buynow.asp?action=detail&prid=1222&crid=195

It says there range is 24 - 180HZ (though doesn't mention to what e.g. + - 3db or 6db)

This a a base to start with.

With the currrent placement 180 degrees on one sub and 0 degrees on the other is the correct approach.

I would expect 2 12 inch drivers in a resonable size room to be able to go lower.

The rear sub is not going very low. 
Do you have sometyhing setup in the Feedback Destroyer Pro 1124 or Onkyo. Looks like the front sub goes from approx 25hz - 40hz then the rear sub goes from 40hz up? If you are not sure disconnect the Feedback Destroyer Pro 1124 and connect direct to the Onkyo and remeasure, no EQ remember.

I know you say this is the best place for them but as above with depth. To gain some room gain try placing subs in front two corners

How big is the room?

When measuring always use 0 - 20,000hz (even with subs) because you need to know what is happening around the frequencies.


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## Bloodta (Sep 15, 2014)

Phillips said:


> Is this the sub, link below?
> 
> http://www.premieracoustic.com/buynow.asp?action=detail&prid=1222&crid=195
> 
> ...


Yes, that's the subs I have. All of the measurements were taken with the Onkyo, and Feedback D Pro not connected. (Laptop outputs sweeps directly to the subs) My room is 14-3/4 long and 13' 1" wide. I will try putting the subs in the front corners as suggested and do some more measurements.
Again, thanks for your time.


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## Bloodta (Sep 15, 2014)

Here is the file from the measurements I took today


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## Phillips (Aug 12, 2011)

Bloodta said:


> Yes, that's the subs I have. All of the measurements were taken with the Onkyo, and Feedback D Pro not connected. (Laptop outputs sweeps directly to the subs) My room is 14-3/4 long and 13' 1" wide. I will try putting the subs in the front corners as suggested and do some more measurements.
> Again, thanks for your time.



No worries glad to help. Good to see appreciation.

I am using the work computer, home one having problems loading some web pages.

Is there any openings in the room e.g. opening into the kitchen dining room?

Ok the room is virtually square which can cause problems though the original combined response looks ok, even without EQ.

What we are trying to do is get better depth with better response.

Are the crossovers on the subs turned off or similar. Its like there are filters.


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## Phillips (Aug 12, 2011)

Bloodta said:


> Here is the file from the measurements I took today


Ok will try again tonight to load web page.


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## Bloodta (Sep 15, 2014)

Just one door into the room. The crossovers are set at 120 on both, as high as they go.


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## Phillips (Aug 12, 2011)

Only a low pass filter (crossover)?


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## Bloodta (Sep 15, 2014)

Phillips said:


> Only a low pass filter (crossover)?


Yes, and it's set to 200, not 120 like I said in my last post. There is a Volume, Phase, and Cross Over dial on the sub


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## Phillips (Aug 12, 2011)

Ok looked at the last graph and looked good, though extension isn't still great. The higher end of the sub looks ok extending to 180ish.

Please can you do a near-field measurement of both subs to see what it is doing, still no EQ and the crossover up as high as it goes. This will give us the closet to sub alone with as little as possible the room contributing.

Another option is to use the RTA in REW to *quickly *find the best position for the subs, without doing several measurement's.

To give you an idea not that this goes for all setups my subs extend to 18hz on the spec sheet, but in room with careful setup extend to 9hz, not bad for 2 x 10'" subs in a 6.2 meter x 3.7meter room with a large opening into the dining / kitchen.


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## Bloodta (Sep 15, 2014)

Phillips said:


> Ok looked at the last graph and looked good, though extension isn't still great. The higher end of the sub looks ok extending to 180ish.
> 
> Please can you do a near-field measurement of both subs to see what it is doing, still no EQ and the crossover up as high as it goes. This will give us the closet to sub alone with as little as possible the room contributing.
> 
> ...


Here are some near-field measurements I took, I put notes in the measurements. Thanks again.


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## Phillips (Aug 12, 2011)

Looked at them last night.
Graph 2 looks the best, sorry how far away was the mic, ideally the measurement should be done outside, personally I don’t but up to you. Could also placing the sub in the middle of the room, don't want no or as less as possible room included in the measurements. Is there anything online of test graph’s etc that you know of?
Matter of interest swap subs from front to back, just trying to see what is going on.
ideally mic should be about couple of inches, mid way from the woofer.


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## Bloodta (Sep 15, 2014)

Phillips said:


> Looked at them last night. Graph 2 looks the best, sorry how far away was the mic, ideally the measurement should be done outside, personally I don’t but up to you. Could also placing the sub in the middle of the room, don't want no or as less as possible room included in the measurements. Is there anything online of test graph’s etc that you know of? Matter of interest swap subs from front to back, just trying to see what is going on. ideally mic should be about couple of inches, mid way from the woofer.


Mic was 2 inches away from the sub. I did swap subs, the measurements were the same.


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## Phillips (Aug 12, 2011)

Please measure left and right (individually) and combined of your main speakers. Just wanting to see how these perform in your room.

Looking at it you need to get some room gain. I red that the PA-15 review that the response wasn't what they expected from a 15inch driver although what it did do very well, so suspect that the 12inch will be not going to go that low in the first place. The specs say 24hz but no tolerance (as mentioned in another post).

So basically use the RTA to find the best room gain then take a sweep measurement (normal) and look at the Waterfall to make sure the decay is ok. As it stands the decay is good, so if you are happy enjoy but I still think there is something going on with the depth. 

Very happy to help but patience is part of it, can take awhile.

See if you can find some measurement graphs and post of someone elses PA-120 sub/s.


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## Bloodta (Sep 15, 2014)

Phillips said:


> Please measure left and right (individually) and combined of your main speakers. Just wanting to see how these perform in your room. Looking at it you need to get some room gain. I red that the PA-15 review that the response wasn't what they expected from a 15inch driver although what it did do very well, so suspect that the 12inch will be not going to go that low in the first place. The specs say 24hz but no tolerance (as mentioned in another post). So basically use the RTA to find the best room gain then take a sweep measurement (normal) and look at the Waterfall to make sure the decay is ok. As it stands the decay is good, so if you are happy enjoy but I still think there is something going on with the depth. Very happy to help but patience is part of it, can take awhile. See if you can find some measurement graphs and post of someone elses PA-120 sub/s.


I ran some 24hz sine waves from REW to each sub, I heard nothing. I cranked the volume on the subs, still nothing. I don't know if there is anything to fix that, outside of new subs. 
I will test left and right, and with subs tomorrow. Thanks again. I can tell you that since I've started using The Feedback Pro, my subs sound so much better, tighter and more crisp.


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## Phillips (Aug 12, 2011)

When the company specify that the range is 24-180hz that is not right.
Maybe email / contact them and explain what you have done and results, maybe send evidence with the measurements.

Is there any other measurements online with these subs?

You say there are no adjustments on the subs themselves, I know I have asked this before?
You use the RCA from the soundcard > subs directly?

Which soundcard / mic combination are you using?

Ok I have red a review and they say the range is 25-180hz + - 3db.

You say you played a 24hz, was this LP or near field?


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## Bloodta (Sep 15, 2014)

Phillips said:


> When the company specify that the range is 24-180hz that is not right. Maybe email / contact them and explain what you have done and results, maybe send evidence with the measurements. Is there any other measurements online with these subs? You say there are no adjustments on the subs themselves, I know I have asked this before? You use the RCA from the soundcard > subs directly? Which soundcard / mic combination are you using? Ok I have red a review and they say the range is 25-180hz + - 3db. You say you played a 24hz, was this LP or near field?


The sub has volume, phase, and crossover adjustments. 
I go from sound card directly to subs, my sound card is the uca-222, I use the Radio Shack SPL as the mic ( I know it's not the best option).
When running the 24hz sine wave, I put my ear to sub and didn't hear anything.


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## ParanoidAI (Sep 29, 2014)

Bloodta said:


> The sub has volume, phase, and crossover adjustments.
> I go from sound card directly to subs, my sound card is the uca-222, I use the Radio Shack SPL as the mic ( I know it's not the best option).
> When running the 24hz sine wave, I put my ear to sub and didn't hear anything.


I've been there before, no mater what I tried, I could get that low wall shaking bass out of em. Thought my test 22hz file was broken. Some sub can't do 20hz. I then upgraded from two Paradigm PDR-10 to one HSU vtf-2 mk3. Oh boy, once you feel 20hz bass, you know what's the fuss all about  I had a much flater line from 30 to 100hz with my two pdr-10 though. I'm saving money to add a 2nd HSU sub.


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## Phillips (Aug 12, 2011)

I think best option instead of chasing something that not going to happen, is to get info (preferably graphs) of the PA 120 subs from the manufacturer. Send them your findings and post back with there answer. Your room isn't big + 2 x 12 drivers should perform better. personally I wouldn't let up with the manufacturers as they have put in misleading info or lack of.

Try different sine waves signals + connect the RCA to the Onkyo and play the 24hz test tone through your main speakers with your current setup meter etc.

Try and place the subs in both front corners using the RTA.

Is there any chance you can get your hands on a Mic + pre/soundcard to try.


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## Bloodta (Sep 15, 2014)

Phillips said:


> Please measure left and right (individually) and combined of your main speakers. Just wanting to see how these perform in your room.
> 
> Looking at it you need to get some room gain. I red that the PA-15 review that the response wasn't what they expected from a 15inch driver although what it did do very well, so suspect that the 12inch will be not going to go that low in the first place. The specs say 24hz but no tolerance (as mentioned in another post).
> 
> ...


Here are some measurements with the Fronts included


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## Phillips (Aug 12, 2011)

Ok graph 5 looks fine.

When entered with the mains not so fine

Please measure the following, sorry this was my mistake not precise enough.
Presumably you have found the best position.
Measurements to be taken at listening position

*No EQ*, going through the Onkyo.

Left main
Right main
Both mains together
Sub A
Sub B
Both Sub A and B

Although graph 5 looks good looks like a lot boosting, not good. Please post the filters used e.g. 38hz Q4.3 Gain 5


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## Bloodta (Sep 15, 2014)

Here are the measurements of the subs going through the AVR with Audyssey On and Off.


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## Phillips (Aug 12, 2011)

Bloodta said:


> Here are the measurements of the subs going through the AVR with Audyssey On and Off.


At work so not sure if you have done below.

Please when doing measurements for both subs and mains set the measurements from 0 - 20,000hz.


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## Bloodta (Sep 15, 2014)

Phillips said:


> At work so not sure if you have done below.
> 
> Please when doing measurements for both subs and mains set the measurements from 0 - 20,000hz.


Here ya go, I believe these are the measurements you wanted. Thanks again


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## Phillips (Aug 12, 2011)

Bloodta said:


> Here are the measurements of the subs going through the AVR with Audyssey On and Off.


Had problems downloading last night (my computer). try again tonight but in meantime.

Able to get post 38 measurements, looks like some boosting going on, sometimes not good. Although Audyssey doesn't tend to boost to much.

When adding in the outboard EQ please list filters used.


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## Phillips (Aug 12, 2011)

Ok able to download.

Can you please take a measurement of each sub with no EQ.

When taking measurements was the crossover set? Please don't use crossovers when measuring that will happen when setting up the delay etc.

Audyssey did a good job on the subs maybe trying to turn the subs down a bit, bit hot. Though if you like it like that that's fine.


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## Bloodta (Sep 15, 2014)

Phillips said:


> Ok able to download. Can you please take a measurement of each sub with no EQ. When taking measurements was the crossover set? Please don't use crossovers when measuring that will happen when setting up the delay etc. Audyssey did a good job on the subs maybe trying to turn the subs down a bit, bit hot. Though if you like it like that that's fine.


The sub measurements with no EQ, are the ones I posted a couple posts up, called "SundayOct12.mdat" I believe.


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## Phillips (Aug 12, 2011)

Ok was there any crossovers set?

Need all measurements to have no crossover and EQ.


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## Bloodta (Sep 15, 2014)

Phillips said:


> Ok was there any crossovers set? Need all measurements to have no crossover and EQ.


No crossovers were set.


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## Phillips (Aug 12, 2011)

Bloodta said:


> No crossovers were set.


Ok so all speakers where set to large in the receiver + subs to full range?

Basically in the high end there is a big lift think that could be possibly be the meter, not sure how accurate it is in the high end.

Bass is ok (maybe a bit hot for my liking), decay is good.

With your responses the subs measurements separately they aren't that good, either is combined no EQ.
With Eq it looks good but as said in previous posts too much boost.
Maybe you could post something in the Audio Processing segment something like does Audyssey boost bass. I am not familiar with Audyssey 
Also I wouldn't be adding any filters other than what Audyssey has done, but that is me.


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## Bloodta (Sep 15, 2014)

Phillips said:


> Ok so all speakers where set to large in the receiver + subs to full range? Basically in the high end there is a big lift think that could be possibly be the meter, not sure how accurate it is in the high end. Bass is ok (maybe a bit hot for my liking), decay is good. With your responses the subs measurements separately they aren't that good, either is combined no EQ. With Eq it looks good but as said in previous posts too much boost. Maybe you could post something in the Audio Processing segment something like does Audyssey boost bass. I am not familiar with Audyssey Also I wouldn't be adding any filters other than what Audyssey has done, but that is me.


Thanks for your help. Front speakers are set to 90hz crossover, not full.


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## Phillips (Aug 12, 2011)

Ok need full range measurements on all speakers and subs, initially.

Reason is to see what your mains are producing in room.


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