Simplified REW Setup and Use (USB Mic & HDMI Connection) Including Measurement Techniques and How... - Page 65

curious about thoughts of the waterfall and ETC'. Seems really hard to get the decay for 40hz and under to be as steep as the rest. Not sure how important it is either, rock music doesnt seem to have too much content down there and in movies the extra rumble does not seem out of place, What do you guys think. Then on the ETC's, I have lots or treatments are those first peaks that are above -20db worth fixing or is the general downslope pretty good? Don't mind the FR, I like this curve!

Looks to be the best compromise. It's worth leaving the mild dip in place in order have smoother overall response and nearfield bass. A second sub is always helpful.

Hi guys, reran Audyssey this morning, change crossover to 80, turned off DEQ. Graphed left and right speaker with subwoofer and it seem better looking than post #1758.

Green with Audyssey turned off and pink with it on

Thanks, Sanjay. Back to more testing.

Behringer 1124P PEQ device purchased, used off eBay. Cost me 70 bucks. Have spent a couple of days over at HTS reading all about house curves, REW and PEQ units, etc etc. Head spinning now but I believe I have the hang of how to use it - just need to experiment. I will of course report back with graphs when/if it makes any difference. I shall be PEQ-ing my subs to try to achieve the best FR and the best splice. The aim is to have the mains crossing over to the subs totally seamlessly. I am looking forward to the challenge but much if it is trial and error so it may take some time.

 

Using REW's EQ option I have experimented a lot with the theoretical correction of the LF response to achieve the above aim and it seems that by applying about 4 PEQ filters between 30Hz and 90Hz (my XO mains-subs is 100Hz), I can do quite a lot. The idea is to use the fewest number of filters possible to achieve the desired result.  Very easy to experiment in REW and then upload the results to the 1124P. 

 

I also have to buy some converter cables so that I can connect the 1214P to my 5509.

 

1214P uses XLR connections. My 5509 has XLR outputs of course (and my subs have XLR inputs). What difference does it make if I use XLR-XLR or use RCA out on the 5509 to a XLR cable adapter - is there a difference in level when using XLR as opposed to RCA? Seem to recall reading that somewhere - if so it will change my sub gain settings will it not (for a comparable trim)?  Any advice on that gratefully received. 

Keith, yes, the XLR outputs are typically higher than the RCA. You can find the output ranges in the Onkyo manual, and the input ranges in the Emotiva manuals.

Some amps will compensate for the higher signal level, some don't. I don't recall how the Emos handle it.


Max

Any idea how the 1124 will work with a Denon 4311 - I also have an opportunity to pick up the same unit as Keith

 

Thanks Max. I am using the PEQ to attempt to goose the subs' response, so the Emo's aren't relevant. Currently I use the 5509's RCA sub outputs into the Submersives via the patch lead that Mark supplies with the subs - IOW, 5509 RCA out into SubM XLR in. (I did it this way mainly because my sub interconnects are in-wall and although I can change them, it is a PITA to do so. As there is no qualitative difference between RCA and XLR in my case (shortish runs, no noise issues) I decided to stay with the RCA interconnects and just use Mark's patch cord to connect the SubMs). 

 

For simplicity, and in order to keep the sub gain trims more or less where they are, I'd prefer to stay with this arrangement, but the Behringer only has XLR (and 1/4inch jack) balanced outputs. I seem to have two options:

 

1. I could go from the 5509's RCA sub outs, via a patch cord, to the Behringer's XLR inputs and from the Behringer's XLR outputs to the Submersive XLR input. 
    
2. OR, I could go directly from the 5509's XLR sub outputs to the Behringer XLR inputs (Behringer outputs remaining the same for both scenarios. 

 

I am hopelessly lost as to what the differences would be and what effect, if any, they would have. As my SubMs gain controls are already practically at 0dB, I don't really need a higher input level raising the sub output volume any more (although I can compensate via the 5509's trim controls, but I am already at -6.0dB and don't really want to drop down much below that.  I can also control the gain of the Behringer of course to compensate for additional output voltage of the XLR connections. Am I right in thinking that if I use the RCA outs on the 5509 and the patch cords to the Behringer's XLR inputs that the gain issue will be irrelevant, or is this a bad idea for reasons as yet unknown to me?

 

As you can see, I am in desperate need of advice here. What would you do?  Many thanks...

 

Pretty much the same won’t it?  Does the 4311 have XLR outputs?

No -as far as I can tell all pre-outs are RCA, no inherent XLR capability built in to the 4311.

 

Then you will have to use the RCA outs to the XLR ins via a patch cord as per my post above. Should be OK, I think. You will also need suitable patch cords to go from the XLR outs on the 1124P to the sub RCA inputs, unless your sub has XLRs.

Hey Guys, is this still the "Simplified REW Set Up and Use" thread, or am I lost somewhere out in the universe?

BTW, anybody remember the name of the OP?

What took you so long?

Have fun.

Michael

First off, I'd check the Behringer manual to see the input and output ranges of that piece of equipment. Some pro-type equipment needs tweaking to play well with consumer equipment. If you're interested in learning more about that rabbit hole, check out the HTS thread about gain matching pro and consumer equipment.


Max

No, he'll use the RCA inputs and outputs on the DLP.

http://www.radioshack.com/product/index.jsp?productId=2062455

 

The Behringer has a setting for compatibility with consumer gear. I have that thread bookmarked ;)

Aren't we making this simple?

 

 

You're in the same place :)  Using the EQ section of REW qualifies as "REW use" doesn’t it?  In fact, it seems to me to be one of the really good things about REW...

 

:)  I decided to try to find a used one, so that I could recoup the entire cost if I decided to sell it later because I couldn't get it to do what I want :)  Ebay came to the rescue this afternoon.

 

There aren't any.

 

Correct me if I am wrong* but my understanding is that the 1/4 inch jacks are also balanced connectors on the 1214P. HST, those adapters might be a simpler solution than the patch cords.

 

In fact, whether they are or not, they are a simpler and cheaper method than using patch cords as I suggested above. Thanks - I will go that route myself, depending on what Max might have to say about my questions earlier.

 

EDIT: I just checked the manual - it says: 

 

17) Use the OPERATING LEVEL switch to change from home recording level (-10 dBV) to studio level (+4 dBu), and vice versa. The level meters are adapted automatically to the selected nominal level, so that the FEEDBACK DESTROYER PRO will always work in its optimum operating range.

Edited by kbarnes701 - 3/10/13 at 2:58pm

Sorry, bad terminology (not my field, after all). The phono adapters go into #17, RCA cables attach there (input/output #1). Similarly, if needing both channels, the other inputs/outputs #2.

It's simplified use (compared to the non-beta REW), but we're too deep in the rabbit hole to jump out now .

I for one am very curious to see if the REW's EQ, combined with other DSP such as the Behringer/Mini as well as Audyssey XT32, will help some of us wrt impulse response. Keith's doing 'research on research', so to speak.

Edit: Keith, did you see the HTS thread on Audyssey MultiEQ? I Googled 'Behringer with Audyssey' and found a thread that suggested coexisting Sub EQ might prove detrimental. However, we have somewhat better tools to measure this now, hopefully.
Edited by sdrucker - 3/10/13 at 3:48pm

As reagrds "research" it might be worth for Keith to consider some of the followings:

1. Do a setup with an A/B testing rig, i.e. with the touch of a button on the remote the PEQ can be engaged/disengaged. That'll help eliminate problems of short auditory memory.
2. Don't rely on beautiful measurement graphs, they work differently than our ears work (read: show more visually nice details than the ones that can be heard).
3. Look out (read: listen carefully) for artifacts introduced by installing a filter (PEQ) on top of another filter (FIR).
3. Start from Reference so that Preference can easily be reset to the starting point, i.e. make sure not to make changes in Audyssey setup (software wise and physical setup wise, both).

Take care!

In theory a perfectly flat FR can have a good impulse response but that ignores the time aspect. FFTs include phase, but most tools only display amplitude so you can't see what the phase is doing. What about REW?

In practice you will probably have to adjust the phase/delay across frequency to obtain the best impulse response iin addition to just tweaking EQ boost/cut.

I mounted my left and right surrounds (M&K S85) in the tri-corners this weekend and ran a measurement.



Beyond 70 Hz, the curves are going in different direction. Is this a phase problem?

 

I have an open mind on it. If it helps me improve things, I'll keep it. If not, I'll re-sell it. Theoretically it ought to help - the problem with Audyssey is that, while it works pretty well, it is obviously not perfect and the problem with that lack of perfection in its automated routine is that it cannot be tweaked afterwards in an attempt to improve what it did. OK, Pro has the curve editor but that is very basic and doesn’t allow for any bandwidth (Q) adjustment at all, for example. The Behringer allows for very precise adjustments (down to a fineness of 1/60th of an octave for example, with a two octave Q spread at the other end of the scale). This should, with the help of REW's predictive EQ, enable us to target very specific problems or to shape the curve in the XO region very accurately to our requirements.  We'll see if the theory works out in practice. I don't have the unit in my hands yet, nor the midi interface nor the bits and pieces I need, but they should all arrive this week. It may be next week before I am ready to start.

 

All good advice, thanks Feri. It is easy, as you say, to bypass the PEQ processing totally at the press of a button so that will make listening tests very easy. I'm aware that it is important not to try to get graphs that look better than we can hear - Graphitis Nervosa and I will be careful to ensure I don't spend unnecessary time on trying to 'perfect' a graph even when there will be no audible benefit. In fact, I am currently not even sure that I can audibly improve on what I already have. But we will see. I shall be aiming to keep the number of filters I use to the minimum and have read a lot of useful stuff on this over at HTS. Hopefully this will minimise any adverse effects. I will also limit my maximum dB boost to 6dB and even then will keep a close eye on that. I intend to run Audyssey one more time, before I start with the PEQ and this will then not be touched in any way after doing do.

 

One thing I am undecided on at this stage is whether to run Audyssey first and then use the PEQ as 'icing on the cake' to make final tweaks to the FR OR to run the PEQ first to get the response where I want it and then run Audyssey. Conventional thinking says to use PEQ first and then run Audyssey, but Craig John's detailed procedure (in the FAQ somewhere) says he ran Audyssey first and then his SMS-1 to fine tune the response. I have the utmost respect for Craig (and Mark Seaton who helped Craig with it) so I am not sure what to do yet. It will be way too much effort for me to try both, so I will have to settle  on one method before I start.

 

I am not sure if REW's EQ process automates this or not, I still have a lot to do to get up to full speed. But I am aware of the issue you raise. I am pretty happy with the way the system sounds right now TBH, so I will measure at the end of the process and if the ETCs and waterfalls etc do not show an improvement (or at least no detrimental effect), then I will go back to square one and reinstall the system as it stands right now.

Wow, Sanjay, adding the second sub really smoothed things out overall and even extended the low end a bit. The graph below is the best I could do with 2 subs and adjusting the phases and the volumes. The graph below has no EQ and compares the single sub to 2-subs.


Towards the end of my measuring session I checked the center speaker with the 2 subs and got a dip at about 76 Hz. I am guessing that dip is a result of the interaction of the center speaker with the subs and the set to a crossover at 80 Hz . Any thoughts on how to minimize that? I adjusted the phase on the sub to get the best frequency response for that alone. Do I need to continue adjusting the phase of the sub(s) with the center and subs combined? Or should I start adjusting the distance settings for the center and sub? Or both?