Graphs from REW

[William Lemmerhirt]

Not eight rather four subs. Two in the front 8ft apart, two in the rear cornered, 12 ft apart in room 14 ft between the fronts and backs.

I put the high pass on it just to attenuate fq after 80 hz. Are you suggesting I should extend the curve more for a gentler slope? With both filters (high and low-pass) obviously the graph is very bell shaped but that's normal right? Since subs are not full ranger and mine are rated down to 24 hz should I expect and shoot for a flatter curve? I don't have anything to compare the graph to therefore I don't know if what Ive presented is good, bad, or ugly.

I would definitely try to flatten that out. 24hz if this system is used for movies at all, your missing out on a lot, and imo even 24hz is too high for movie subs. Subs rolling off at 70 and basically out of the picture by 50 wouldn't sound very good imo.

 

[Mitchibo]

If I'm reading your sig correctly it appears that you have 8 klipsch subs? Is that all in one room? And with that many your output above appears as above? Something isn't right. What happens if you turn OFF the high pass and measure?

Not eight rather four subs. Two in the front 8ft apart, two in the rear cornered 12 ft apart in room 14 ft between the fronts and backs.

I put the high pass on it just to attenuate fq after 80 hz. Are you suggesting I should

The room is in control of bass. You can leave it to the magic of Audyssey and hope it's results are satisfactory (which your measurements, are not) or get out a tape measure and start measuring ALL of the parallel boundaries of your room.

1131(feet per sec) / measurement (in feet) = Room Mode - which will measure as a peak or null at the LP depending on it's +/- phase cycle - subwoofers are pressure sources, placement is everything

Frequency + Amplitude + Q = DSP Filter.

(center of peak or null) + (dB increase/decrease to reach relative level) + (bandwidth of resonance measured in hz) = DSP Filter

Those 3 parameters allow you to create a DSP filter to overcome the natural response of producing frequencies that are larger than the dimensions of your room. (20 hz = 56.5 feet for example)

Measurements MUST be taken as 1/24 octave so that nothing is masked. Windows and doors allow flex in boundaries which will lower the measured resonance frequency from predicted. But when you know which boundaries are influencing a frequency, the orientation of subwoofer(s) at that boundary allows you to constructively or destructively drive the standing waves.

If you're really serious and want to learn more, 'Sound Reproduction' by Floyd Toole is the textbook on the subject. He just released the 3rd edition so be mindful which one you order. This is a lifetime of research backed by double blind testing with only minimal mathematics being presented, such as what I've suggested.

I finally found an affordable copy of this in paperback. Didn't want to spend $175 for the hard edition. That's what she said...

Thank you for the input.

 

[Pogre]

Not eight rather four subs. Two in the front 8ft apart, two in the rear cornered, 12 ft apart in room 14 ft between the fronts and backs.

I put the high pass on it just to attenuate fq after 80 hz. Are you suggesting I should extend the curve more for a gentler slope? With both filters (high and low-pass) obviously the graph is very bell shaped but that's normal right? Since subs are not full ranger and mine are rated down to 24 hz should I expect and shoot for a flatter curve? I don't have anything to compare the graph to therefore I don't know if what Ive presented is good, bad, or ugly.

It's not your curve so much as you have 4 subwoofers and you have no bass. You're getting the same low end extension as my bookshelf speakers. Your subs look like they need subs.

 

[Mitchibo]

It's not your curve so much as you have 4 subwoofers and you have no bass. You're getting the same low end extension as my bookshelf speakers. Your subs look like they need subs.

Thanks for the feed back. I think I'll bypass the filters and start over. Each time I jack with this mini I learn something new. You should jump in,the waters warm.

 

[carole5]

May I ask which tool did you use for the graphics, please?

 

[TheWarrior]

May I ask which tool did you use for the graphics, please?

REW

Unsure of which Mic was used, but the minidsp UMIK is highly recommended.

 

[Pogre]

Thanks for the feed back. I think I'll bypass the filters and start over. Each time I jack with this mini I learn something new. You should jump in,the waters warm.

That's what I'd do.

Oh, I jumped in the waters. Got my mini hooked up now with filters generated by REW, then ran Audyssey. Check it out:

I'm pretty damned happy with this result. There is no smoothing in this measurement. I'm gonna just listen and enjoy for a while now. I'll prolly go back and do some more in a week or 2. See if I can do something about that dip at around 22hz and smooth out the response above 120hz or so. There is a definite, audible improvement in my system.

 

[William Lemmerhirt]

Hey poges, I think he was inviting you into his water. Since you're an expert now.

 

[Pogre]

Hey poges, I think he was inviting you into his water. Since you're an expert now.

I sure don't feel like an expert! It was a long, torturous 3 days for me, but I do know what a notch filter is and how to apply it now!

 

[William Lemmerhirt]

I sure don't feel like an expert! It was a long, torturous 3 days for me, but I do know what a notch filter is and how to apply it now!

I think you learned a lot more than that. Expert? Not yet. But you definitely know how to do what you want to do.

 

[TheWarrior]

View attachment 22031





Red line is subs w/mini and no Audyssey, blue line is subs w/mini and WITH Audyssey

Those subs are not capable of deeper bass! You cannot apply boost below the resonance frequency of the driver, which is likely 30 hz or above (phase data should indicate).

So with that in mind, I'd say what you've achieved is quite good and all you are really missing is the deep, usually artificial (unless you listen to pipe organs) LFE movie bass. Worth upgrading to, some day. But what you've got ain't shabby!

What is your opinion of the sound quality with and without Audyssey?

 

[Pogre]

Those subs are not capable of deeper bass! You cannot apply boost below the resonance frequency of the driver, which is likely 30 hz or above (phase data should indicate).

So with that in mind, I'd say what you've achieved is quite good and all you are really missing is the deep, usually artificial (unless you listen to pipe organs) LFE movie bass. Worth upgrading to, some day. But what you've got ain't shabby!

What is your opinion of the sound quality with and without Audyssey?

He's not getting much under 50hz tho, right? My bookshelf speakers can hit 50hz and do it with authority. I know he doesn't have big subs, but there are 4 of them. He should be getting deeper extension than that graph shows.

 

[TheWarrior]

He's not getting much under 50hz tho, right? My bookshelf speakers can hit 50hz and do it with authority. I know he doesn't have big subs, but there are 4 of them. He should be getting deeper extension than that graph shows.

Not actually sure they can be called subwoofers. I was trying to be optimistic since there's been 4 purchased already.

Might recommend swapping two of the 12" assuming you only have 2 total systems going, I see you have 4 of the 12"'s.

 

[William Lemmerhirt]

I agree those subs could stand an upgrade, but from 70hz to 25, there down by like 40db. Definitely need to change the filters.

 

[Mitchibo]

May I ask which tool did you use for the graphics, please?

REW, MiniDSP HD2x4, UMK1 mic.

 

[Mitchibo]

That's what I'd do.

Oh, I jumped in the waters. Got my mini hooked up now with filters generated by REW, then ran Audyssey. Check it out:

View attachment 22042
I'm pretty damned happy with this result. There is no smoothing in this measurement. I'm gonna just listen and enjoy for a while now. I'll prolly go back and do some more in a week or 2. See if I can do something about that dip at around 22hz and smooth out the response above 120hz or so. There is a definite, audible improvement in my system.

Is this all 5.1 averaged or just specific set of speakers?

 

[Mitchibo]

Those subs are not capable of deeper bass! You cannot apply boost below the resonance frequency of the driver, which is likely 30 hz or above (phase data should indicate).

So with that in mind, I'd say what you've achieved is quite good and all you are really missing is the deep, usually artificial (unless you listen to pipe organs) LFE movie bass. Worth upgrading to, some day. But what you've got ain't shabby!

What is your opinion of the sound quality with and without Audyssey?

That's a good question. For me Audyssey was a huge help as I don't have experience to manually set distance and EQ each speaker X 11. So it's all about where you were, to where you are now. I know people here and there can do as good or better than Audyssey, some people hate it. It was an improvement from where I "was". Our learning and tastes are pretty much linear. When my brain gets bigger I may bypass it and do it all manually.

 

[Mitchibo]

He's not getting much under 50hz tho, right? My bookshelf speakers can hit 50hz and do it with authority. I know he doesn't have big subs, but there are 4 of them. He should be getting deeper extension than that graph shows.

Re-working the EQ for the subs. Eliminating high pass and boosting the lower hz has helped but as you can see these 12's only go down 24 (as rated by the factory which may be generous).

My goal is not just to have lots of it, rather tighter punch. Four will shake stuff off the shelves literally. I had to tape a few things down so they stopped sliding off. If I can get a handle on these, swapping out with larger units should easier...as soon as I find some dough$$ laying around.

 

[panteragstk]

I honestly got much better results building my own subs within my budget than purchasing pre maid within it.

Bang for the buck you can't go wrong. Is that something you might consider?

 

[Mitchibo]

I honestly got much better results building my own subs within my budget than purchasing pre maid within it.

Bang for the buck you can't go wrong. Is that something you might consider?

Hmm. Other than building cabinets, wiring, and the unknown...it would be a great challenge. Presently, due to to my sophomoric audio knowledge I'll be stuck in the short bus.