Flatness target vs number of filters

[TheBoom]

Hi all,

Would like a general opinion on something I’m trying to decide between.

What is a the maximum number of filters per speaker you would recommend?

I’m in a position whereby I’m trying to limit myself to 5 per speaker (excluding sub) but in doing so I would have to limit myself to a flatness target of around 5db instead of the recommenced 3db.

I previously went ham with 8-10 filters per speaker and managed to get a somewhat flat curve within 3db.

Trying out a more conservative approach of 5 filters but unable to get a flatness of anything less than 5db.

Opinions?

 

[Wayne A. Pflughaupt]

Are you using REW to determine your "flat curve" and effects of the EQ?

Regards,
Wayne

 

[TheBoom]

Are you using REW to determine your "flat curve" and effects of the EQ?

Regards,
Wayne

Yes with a umik-1. Eq is applied via Jriver MC.

 

[Wayne A. Pflughaupt]

For your evaluations I would recommend using 1/3 octave smoothing, which will get a graph that looks more like what you’re actually hearing. You may find after that that very little EQ is actually needed.

The goal is not a pretty graph but to get an improvement in sound quality. Typically all that’s required for that is to address the worse peaks or troughs in response – ones that are severe, or broad. That typically will require only a few filters.

Further wisdom on the topic, the following was posted by Floyd Toole at the AVS Forum last year:

Small peaks and dips in room curves are likely to be caused by non-minimum phase phenomena, most likely caused by reflections and cannot be equalized. To two ears and a brain they are innocuous spaciousness, not coloration. It is attempts to "correct" such fluctuations that lead to degradation of well designed loudspeakers. So, above the transition frequency, small details in steady-state room curves should be ignored because unless you have comprehensive anechoic data on the loudspeakers you don't know what caused them.

Regards,
Wayne

 

[TheBoom]

Used variable smoothing and somewhat managed to get a decent result. Stuck to 300hz max instead of 10000hz like previously and ended up with lesser filters. Did however use more filters for the sub as it was all over the place.

 

[Wayne A. Pflughaupt]

Same holds for subwoofers, too. Might want to wade through this:

On Minimal EQ, Target Levels, and a Hard-Knee House...

www.hometheatershack.com

Regards,
Wayne

 

[Harrycr]

Hi Wayne
I have two subs running mono with the eq I believe the use of same set of filters get inputed into each sub, does this include gain or does it get halved for each sub, eg REW suggestion for filters f = 40 Q = 5 Gain = - 9 do input the gain of - 9 for each sub or - 4.5 for each sub?
Also what's the best way to level match each sub to each other?

Thank you

 

[Wayne A. Pflughaupt]

If the two subs are co-located, it’s pretty easy – just play a pink noise signal from REW and level-match with an SPL meter.

If they are in different locations, that’s a bit trickier, so I’m not sure if that method will work. I’d suggest looking for a thread about “Bass Preferences “ at AVS Forum, you can probably find a good answer there.

Regards,
Wayne

 

[Harrycr]

Thanks Wayne.
Please can you answer the other question in my last post about the filters.

Thanks again

 

[Wayne A. Pflughaupt]

Sorry about that!

Hard to say for sure, I’ve never used a set-up like that. However I have sent the outputs from a stereo equalizer to a subwoofer’s L/R inputs. If only one input was getting EQ (i.e. I forget to set equalizer to adjust both), then a second measurement didn’t get the gain reduction or boost I was expecting. After I set the equalizer to send EQ to both, then I got the measurement I was expecting.

So based on that I’d recommending setting the filters as REW recommends for both subs. If the subsequent measurement gets way more adjustment that you expected, then you could try the half-gain thing you mentioned.

Regards,
Wayne

 

[Harrycr]

Thanks Wayne appreciate it. Will let you know how it goes. I used your scale 20-130 and 6th smoothing. Listening to it now and seems ok. I will measure to see how that looks and what my ears are telling me.

 

[TheBoom]

Thanks for the link and inputs. I did accidentally match the subs to my mains target level when i didn’t realize it was actually 10db higher from the LFE channel, that was the main issue.

 

[Harrycr]

Hi Wayne the curve wasn't too far off used the settings I listed above. Just used four filters for each sub with low q think highest was 2.3. I used your knee curve is this for music or HT?
Didn't you have a Yamaha receiver?

Thanks again

 

[Wayne A. Pflughaupt]

I use the same curve for music and movies, but I think some people us a different one for each. And yes, I have a Yamaha.

If you aren’t happy with the results you might try equalizing all the subs with a single set of filters. Most people seem to agree that works best.

Regards,
Wayne

 

[Harrycr]

Hi Wayne you had the Z9 I think.
I've still got mine but is playing up keeps on intermittently turning off or won't turn on at all. Have you had this problem?
I am using one set off filters inputed into each of the subs.
Why do people insist using no smoothing or variable for eq of subs? You recommend 1/6 smoothing is sufficient.
What I have noticed from shifting one sub from the front to the back the differences between the whole room in bass strength has improved alot, mainly when I walk past the rear sub is the real audible difference gets a bit much.
I wonder if putting too many filters or high q filters that would spoil that?
The sound stage has improved too.

Thanks

 

[Wayne A. Pflughaupt]

Yes, I had that problem when I first bought my Z9. I dug up a service bulletin that said all the screws on the back panel in the area of the speaker terminals need to be tightened. That fixed it and I haven’t had any more problems.

Can’t tell you about the smoothing. It caught on in the early days of REW and has remained.

Can’t help on the subs either, I’ve never had two subs in different locations.

Regards,
Wayne

 

[Harrycr]

Thanks.

I tightened about 2 years ago and problem went away but has reappeared, tightened again but problem has remained. There were just the x6 screws that needed to be tightened?

 

[Wayne A. Pflughaupt]

You might try loosening them a bit and then re-tightening. Maybe a half-turn or so (don't over-do it!).

Hope you can get it fixed, it is a superb amplifier. In fact, I intend to use it as a basic power amp once I upgrade to a newer AVR.

Regards,
Wayne

 

[Harrycr]

Thanks
Is there just the 6 screws? It's a pain to pull out where it's located.
I really hope can fix too.
Totally agree, someone on a forum asked me what I had his reply, that is a beast.
The sound is so clean. I haven't heard anything lately that can compete and the price. It's like it doesn't even break into a sweat. I think that 170w is true watts. Personally I think that AVRs of today do too much, picture as well thought that was the reason for players. Although the Z9 does upscaling. If I was going to complain it would be the YPAO eq of that error. For 2 channel which is its main usage is just so good. Do you use yours for theatre or 2 channel?

 

[Wayne A. Pflughaupt]

It only appears to be 6 screws, but I’m going on pictures I can find online.

I use mine for everything – TV, movies, music.

I hope to upgrade to a newer AVR with HDMI soon, and when that happens I’m going to use the Z9 as an amplifier, via its multichannel inputs

Regards,
Wayne

 

[Harrycr]

Are you going to use the pre out for mains and centre?
Which receiver are looking at if you don't mind me asking.
I tried to eq at 75hz q 2.6 - 7 and didn't make hardly any difference with a 80hz xover wondering if too close to the xover?

 

[Wayne A. Pflughaupt]

Probably going to replace it with either an old RX-Z7 or RX-V3900. Don’t care much for the looks of the Aventage Yamahas, plus I like the orange display. We really just need something with HDMI. Never needed HDMI before because our primary device was a TIVO unit with component video output. However, now our primary viewing device is a Roku, so HDMI is needed to get programming in 5.1. Plus you can get those older units on ebay dirt cheap.

I'll be using all the 5.1 pre-amp outputs from the "new" receiver. Via its multichannel inputs, the Z9 will function as a stand-alone 5-channel amplifier.

Hard to comment on the EQ without seeing a graph

Regards,
Wayne

 

[Harrycr]

With the Z9 thought it only had pre out and in for mains & center?

 

[Wayne A. Pflughaupt]

That is correct. However, I will use the multi-channel inputs. They can function as direct-access connections to the internal amplifiers.

Regards,
Wayne A. Pflughaupt

 

[Harrycr]

That is correct.

Regards,
Wayne A. Pflughaupt

Hi Wayne hope you are good.

Have you still got your Z9?

Mine has a hissing/white noise coming from the front right, when not playing anything, msic etc.
When i turn up the volume the hiss/white noise doesnt increase.

The tech guy said it might be the DAC or DSP.
Is there anyway i can save it?