Can Audyssey replace a BFD?

[mattkhan]

Hi

I now have an amp (Onkyo 805) that has audyssey onboard and some brief reading around suggests that some have found it can do a good enough job to replace a dedicated EQ device (i.e. BFD, SMS-1). Anyone have such experience here? If not I'm assuming I run Audyssey on an EQed sub to allow it to cope with the flattened response to give it less work to do.

It's a shame the Onkyo doesn't show you the inroom response graphically, it must have that information stored locally after all.

Cheers
Matt

[russ.will]

I run Audyssey and an SMS-1 and wouldn't do without either.

Russell

[UrbanT]

Hi Matt.

I had full EQ on my Tag McLaren Dual processor. Having gone completely HD I changed it for the Onkyo 875 hoping the Audyssey would do a decent job. Although I find the amp excellent, the Audyssey is the only thing that doesn't really work for me. Having tried various setups for Audyssey, I gave up and bought another BFD.

The BFD does everything I want (or think I want, I have considered the SMS-1) and I'm far happier with it as I can alter it to my taste, whereas Audyssey is pretty much 'here is what you get'.

I had a BFD a few years ago and to be fair, it did take some time to setup properly. But these days with the improved software available, the process is relatively simple and virtually automatic.

Hope this helps

[Peter Galbavy]

My understanding, which may well be a load of old rotting fish, is that while Auddessey can help by dropping nasty spikes and helps sort out the freq response across multiple channels it will not lift any dips to fill in gaps in responses - only lowers peaks.

Is this right or have I just misread stuff (again) ?

[eviljohn2]

Originally Posted by Peter Galbavy

My understanding, which may well be a load of old rotting fish, is that while Auddessey can help by dropping nasty spikes and helps sort out the freq response across multiple channels it will not lift any dips to fill in gaps in responses - only lowers peaks.

Is this right or have I just misread stuff (again) ?

I don't know the full details but I'd be very worried if it started boosting parts of the signal without me knowing about it. You shouldn't really add EQ to boost a signal as it very quickly eats up all of your amplifier power.

[ISHANTY]

i have the sms-1 and i wouldn't be without it works well for me

[mattkhan]

just to clarify, I do currently have a BFD and find it (and REW) do all that I need it to.

[UrbanT]

Originally Posted by mattkhan

just to clarify, I do currently have a BFD and find it (and REW) do all that I need it to.

Have you tried the 805 without the BFD, but with Audyssey engaged? If so, how did you find it?

[mattkhan]

Originally Posted by UrbanT

Have you tried the 805 without the BFD, but with Audyssey engaged? If so, how did you find it?

not had a chance to listen yet, I only got it installed yesterday and got to the stage of running the audyssey process once to see how long it took and what it suggested. FWIW not too crazy, 100 for the front two & 70 for the centre (all M&K S85s) and then 120 for the rears (M&K 55 Mk2 Tripoles). I ran this with the BFD in bypass.

I now need to run REW to see what it did & have a listen. I then plan on reinstating the BFD and rerunning Audyssey to compare the difference. I think that's my Saturday gone then

will post pics once I'm done.

[mattkhan]

I grabbed some time to run through audyssey again tonight and thought I'd put the graphs up. Listening time is still Sat but I thought I'd get the boring bit out of the way tonight

The graphs are using the traditional 15-200Hz/45-105dB scale and there is a some degree of apples to oranges in the comparison (russet to cox's perhaps ) in that there are necessarily 2 seperate audyssey runs with different levels of background noise & microphone positions. I tried to put the mic in approximately the same position and took 6 measurements each time so hopefully that is as comparable as can be. Obviously the presence of a BFD in the mix means that crossovers, distances & levels are different. The suggested crossovers are now closer together (90 at the front, 70 in the centre and 100 at the rear) so I'll leave that as is and perhaps change the centre one if required. I used to run a 100Hz crossover as I couldn't discern directionality & it offered the smoother (but still slightly shambolic) crossover.

So some graphs, filters & waterfalls all round. In each graph;

• magenta = no EQ
• dark blue = audyssey only
• murky green = BFD only
• dark yellow = audyssey and BFD

Audyssey vs No EQ
2123742862_d9ab0042c3.jpg

No EQ Waterfall
2123742870_922d0d8719.jpg

Audyssey Waterfall
2123742868_fec8342ed7.jpg

BFD vs No EQ
2123742864_ae485a895c.jpg

BFD Waterfall
2122992337_b774649ae2.jpg

All Together
2123742860_57d5b211a6.jpg

BFD & Audyssey Waterfall
2123742866_262beb119b.jpg

I draw the following conclusions based on the graphs alone;

• the crossover region is significantly improved, about 8-10dB louder between 100-140Hz
• it looks like the room null at ~60Hz is causing audyssey to boost around there but that is lifting the ~50Hz and makes it look like a resonance
• audyssey alone has a good stab at tackling the main room mode at 37Hz, it doesn't cut it as hard as I do but it does bring it down somewhat into line

The listening test should be interesting particularly with respect to the crossover area as that has always been a problem in my room. Any recommendations for material that might bring that to the fore? Perhaps music might be a better bet??

Cheers
Matt

[AngelEyes]

Interesting thread this, I currently run the 805's Audyssey over my BFD EQ and it does sound very good but I didn't bother with just Audyssey.

I may give this a shot at some point and see how I get on because I have an annoying Ground-Loop-Hum from the BFD which is doing my head in and if I can do without it I may well give it a go.

Interesting that you let Audyssey set the crossovers on the speakers, almost everyone I have spoken to says to overide them and set them to 80hz (small), especially as I have sat speakers. What is the perceived wisdom of either method? (Audyssey usually picks 90-100hz depending on the speaker)

As a side note I finally got my HTPC to output uncompressed HD Multichannel PCM to my Receiver via HDMI . I had hoped the Digital only connection would do something about the PC noise I hear through my speakers but it looks like it is definately the BFD to blame!

My only other option is to spend a mint and cross to the dark side with a SMS-1, as it being earthed should remove my problems.

Adam

[UrbanT]

Thanks for taking the time to post all the graphs Matt.

Unless I've misread it, it seems the Audyssey isn't doing a great job with the bass and the response is still lumpy. The BFD looks far flatter.

When I get the new sub after Christmas I'll try and find some time to run Audyssey again, and measure the response. Then I'll try the BFD and compare the results.

If only I had a sub

[AngelEyes]

Originally Posted by UrbanT

Thanks for taking the time to post all the graphs Matt.

Unless I've misread it, it seems the Audyssey isn't doing a great job with the bass and the response is still lumpy. The BFD looks far flatter.

When I get the new sub after Christmas I'll try and find some time to run Audyssey again, and measure the response. Then I'll try the BFD and compare the results.

If only I had a sub

The crossover area does look a lot better with Audyssey though and the Bass doesn't look that bad... but again I am not all that great at reading the graphs either... Maybe I will let Audyssey run the crossover after all.

[mattkhan]

Originally Posted by UrbanT

Unless I've misread it, it seems the Audyssey isn't doing a great job with the bass and the response is still lumpy. The BFD looks far flatter.

I think it is struggling to compensate for the peak-null combo at ~37Hz & ~60Hz. On the graphs alone my filters do a better job then the BFD.

I think it's worth bearing in mind that audyssey is measuring across 7 positions on my sofa whereas I'm taking a reading at just one position (the main listening position). From previous readings I know that that peak-null combo does differ fairly significantly across those positions & my filters are set to deal with it primarily at the main position with a secondary nod towards the other end of the sofa.

Originally Posted by AngelEyes

Interesting that you let Audyssey set the crossovers on the speakers, almost everyone I have spoken to says to overide them and set them to 80hz (small), especially as I have sat speakers.

I wanted to see the difference between a completely automated setup and my own purely manual attempt. After listening I may change things but 70-100Hz across the 3 seems a reasonable interpretation of what my speakers can actually do. The only one I may change is the centre at 70Hz which seems too low to me.

Cheers
Matt

[russ.will]

Originally Posted by mattkhan

I think it's worth bearing in mind that audyssey is measuring across 7 positions on my sofa whereas I'm taking a reading at just one position (the main listening position). From previous readings I know that that peak-null combo does differ fairly significantly across those positions & my filters are set to deal with it primarily at the main position with a secondary nod towards the other end of the sofa.

You've hit the nail on the head there as Audyssey is trying to apply an averaged set of responses for all of the microphone positions.

It would be interesting to see you overlay on a graph the same 7 positions as taken with the BFD/RS SPL and then see what we would choose as the best average filter positions. That discussion would result in a thread all of it's own.

For instance, the 50Hz odd peak in my room does not exist at my seating position. The wife's, 2ft to the left, suffers to the tune of +12dB, but any reduction results in a corresponding dip back at my seat. Which would you choose?

There are some points worth noting about the implementation of Audyssey. Audyssey state that rather than trying to equalise specific seating positions (with the exception of the main one or two), that effort should be made to allow the EQ to build a picture of the room.

To quote Audyssey:

"...we knew if you EQ for the single sweet spot then every other position would suffer from much poorer frequency response. (And that was one of the reasons for the bad name 1/3 rd octave equalizers were given.-Tom) Initially Denon and every other potential customer thought 'let's have two modes'. One for a sole listener and one for when you have several listeners in a room. Well, it turns out if you EQ a whole room the audiophile seat gets better. If you take more of the problems of the room into account you're fixing a bigger area than just the audiophile seat...."

This means spacing the microphone positions out and measuring areas even if people don't sit there. I position mine with three across the main seating positions and then three at least a one meter in front, even though no-one will ever, ever sit there.

An interesting point to be drawn from that quote, is that if EQing for the sweetspot makes everybody else's position worse, then not EQing for everybody else can make the sweet spot better. In purely sub-bass terms then, it may be better to utilise PEQ when it's you alone and engage Audyssey for group viewing. However, the rest of the frequency range will loose out, as will spacial imaging and effects steering and these are at least as important as bass.

This Audioholics article provides good background from the horses mouth (it's also the one quoted above) and indeed I've achieved my best results following the methodology Audioholics have refined in their various articles.

As it stands and as Matt correctly points out, he's bending Audyssey to match the way we use a BFD because that's what we understand, even though Audyssey specifically does not work in the same way. Personally, once I've EQ'd out the main two or three room peaks in the traditional manner, I no longer bother trying to flatten the curve ruler flat/smooth. I let Audyssey do it's stuff because the magic it can work, positively affects far more of the frequency range to a greater degree than flattening out a few small peaks you can't hear.

I'm just worried that people may be tempted to throw the baby out with the bathwater so to speak.

Russell