monitoring: to dsp, or not to dsp?

[jdjustice]

i am shopping (still) for a new pair of monitors with a 6-8" woofer size.
my budget is around $2k but could go up to as much as $4k if i wait a few more months to make the leap.
i don't want to spend more than i have to, obviously.

here is the particular quagmire i find myself in:

it seems many monitor manufacturers have recently come out with systems with DSP calibration.

originally, i had narrowed my monitor choices down to the following speakers:

• Genelec 8040A
• Tannoy Precision 6D
• Focal Solo6

all of these choices, with the exception of the Genelecs, are under $2k.
then i started reading about all the new DSP-calibration monitor systems, and my prospective budget went up.

the new list:

• Genelec 8240A
• Tannoy Precision 6 iDP
• Focal SM8

now, the Focals would be *quite* a stretch for me and i am not so sure i could handle the hit they would make on my wallet.
however, the Genelecs and especially the Tannoys are more reasonable.


main question:
are these DSP-calibration systems worth the extra hundreds and sometimes thousands they cost?

i may just say fukkitall and get the Dynaudio BM6As.
they were the original choice before i got all confused with this DSP stuff.......

any thoughts/comments welcome!


cheers.
~j.d.

[gainreduction]

I've had the Gen 8240's for a while now and they are the best thing I've bought in a long time. thumbsup (upgraded from non-dsp genelecs)

Mixing and tracking with confidence now.

[Ethan Winer]

j.d.,

it seems many monitor manufacturers have recently come out with systems with DSP calibration.

For the most part that's just marketing hype. There's no way that DSP can truly compensate for room acoustics problems. About the only thing useful that can be done electronically is to cut the one or two most prevalent LF peaks a few dB. Note that this does not reduce the low frequency ringing which is at least as damaging as the peaks, nor can DSP do anything at all for the nulls which are usually even more damaging. The blurb below is from my Acoustics FAQ, explaining some of the many limitations of electronic room "correction."

--Ethan

Another common misconception is that equalization can be used to counter the effects of acoustic problems. But since every location in the room responds differently, no single EQ curve can give a flat response everywhere. Over a physical span of just a few inches the frequency response can vary significantly. Even if you aim to correct the response only where you sit, there's a bigger problem: It's impossible to counter very large cancellations. If acoustic interference causes a 25 dB dip at 60 Hz, adding that much boost with an equalizer to compensate will reduce the available volume (headroom) by the same amount. Such an extreme boost will increase low frequency distortion in the loudspeakers too. And at other room locations where 60 Hz is already too loud, applying EQ boost will make the problem much worse.

Even if EQ could successfully raise a null, the large high-Q boost needed will create electrical ringing at that frequency. Likewise, EQ cut to reduce a peak will not reduce the peak's acoustic ringing. EQ cannot always help at higher frequencies either. If a room has ringing tones that continue after the sound source stops, EQ might make the ringing a little softer but it will still be present. However, equalization can help a little to tame low frequency peaks (only) caused by natural room resonance, as opposed to peaks and nulls due to acoustic interference, if used in moderation.

[Drumsound]

I'd be personally wary of:
A) Running more processing, and conversion on my mixes.
B) Latency. If you work in real time, on a mixer, or doing punch-ins, nothing will be quite right.

[drumpike]

I personally believe, so far, that this new wave of "adjusting to your room" monitors is a marketing fad that is certainly impressive. But I can only speak from my own experience. I have a pair of Solo6 and they have changed my world - no more troubles relating to the real world.. no fatigue during long mixing sessions...I love them. First though, I made sure that my room sounded good.

good lluck with your choice!

[AndreH]

Why not just run a room analysis and apply an EQ curve to your current set of monitors? You could even just drop a Linear Multi- or Low-band on the output aux or master fader (bypass at mixdown, of course).

Actually, I'm looking hard hard at some of these new monitors myself; in fact, I just brought home a pair of the JBL's (which sounded the best to my ears at the store, but aren't nearly as satisfying in my studio...I hope the calibration makes a difference when the kit arrives).

It appears the Genelecs do more than just EQ tailoring, and I can see how the phase and time alignment option would be of benefit...but harldy impossible to replicate (minus the instant recall for various locations) with careful placement of your monitors.

FWIW, I already have 25 bass traps in my room, and I still suffer from a lack of low-end in my mix position. I'm exploring all my options...


Andre

[AndreH]

By the way, have you seen the disgusting gold color of the 8200 series Genelecs? I could not live with that, no matter how good they sound...my musical vibe would be destroyed and I'd be embarrassed when clients came to the studio.

I emailed Genelec today and asked if they could do a pair in black. If they can't and the speaker sells poorly, we'll never know whether it was because of so many purists bashing room EQ on GS (maybe for good reason), or simply because they're the fugliest speakers ever made! Criminy, they already were even before they got painted gold.


Andre

[gainreduction]

The 8200 series are now the same color as the 8000 series. It was only the very first batch that had that ugly champagne color.

[AndreH]

Originally Posted by gainreduction

The 8200 series are now the same color as the 8000 series. It was only the very first batch that had that ugly champagne color.

Cool! This was verified by a response from Genelec today (though the Sweetwater dudes still insist it's only available in gold...must be trying to get rid of a few pairs in that color).

I ran some tests on my room today to see where the problems are & play around with the parametric EQ on these new JBL 6328p's. I have bumps at 40 and 180Hz, but the single JBL EQ only goes up to 96Hz. So, I made some adjustments and now the 40-50Hz region is much better...flatter than any other bass region, in fact (at the mix position, that is).

They do seem to sound more linear down there now, but I'd probably notice a bigger difference if I were able to correct the 180Hz problem that affects my perception of mid frequencies more. I believe the Genelecs have more possible adjustments across a broader range, and it's more automated...but they cost almost $1k more.

I also ran tests using my BM6p's with a KRK S12 sub, and aside from the existence of more frquency content below 40Hz (the JBL's rolloff), the room curve looks pretty similar up to ~200Hz. This made me want to correct the 40Hz problem in the sub, but I'd need a hardware EQ or to apply one in software, which would then affect the JBL's as well.

I'm now thinking that buying a monitor that has built-in calibration options (or buying one for mainly that reason) may not be the most flexible way to go unless you need to carry your speakers around with you a lot. It's easy enough to analyze your room with some software help (apparently EFT works great, though I've been using Room EQ Wizard with great results...and it's free) and make some corrections with a hardware or software EQ which you can also apply to alternate sets of speakers which, in my room, will need very similar correction in the low end.

I'll wait until I hear the Gennies before I make a final decision, since they apparently do more than just EQ...plus they might sound great regardless of their calibration options (but then 8040 would make more financial sense).

In the meantime, I'm getting used to the JBL's in my studio...they're definitely letting me hear things I couldn't with my 1031's.


Andre

[barefoot]

Originally Posted by Ethan Winer

...nor can DSP do anything at all for the nulls which are usually even more damaging....

Ethan,

We've discussed this before in another thread, but I'll reiterate. The type of signal processing used in these "room calibration" algorithms is not simply EQ. FIR (Finite Impulse Response) filtering gives you astonishingly more control over the waveform than EQ. You can, in fact, micro manipulate the waveform's amplitude and phase such that you eliminated nulls. So, you're incorrect on this point. HOWEVER, you are very correct with regard to the spatial limitations of any such signal processing. With modern DSP techniques you can eliminate nulls and do all sorts of fancy stuff. But this is absolutely limited to a very specific point in space. If you move your ears slightly from the optimal listening position, all bets are off. I actually cringe to think of what that off-target signal is doing. Not to mention that intensive FIR filtering generates some rather unsavory artifacts such as pre-echo. Anyhow, I just wanted to clarify those points.

Thomas

[Ethan Winer]

Thomas,

The type of signal processing used in these "room calibration" algorithms is not simply EQ.

Understood, but they still can't improve nulls or reduce ringing over a usefully wide physical range. So if it's possible in theory, but not in practice, who cares?

I just forwarded to the info@ address on your company's site an email about this that you will surely find interesting. I can't explain too much publicly now, but on Monday if this thread is still active I'll post a link to an article I just finished showing exactly what these DSP systems are capable of. (And what they're not capable of...)

But this is absolutely limited to a very specific point in space. If you move your ears slightly from the optimal listening position, all bets are off.

Exactly my point. These systems can't even get the response correct for both ears at the same time!

--Ethan

[barefoot]

Originally Posted by Ethan Winer

These systems can't even get the response correct for both ears at the same time!

Well, you can do it for both ears using two speakers and stereo processing..... but make sure your head vise is precisely adjusted!

Got your email. Thanks!

Thomas

[Ethan Winer]

Originally Posted by barefoot

Well, you can do it for both ears using two speakers and stereo processing..... but make sure your head vise is precisely adjusted!

Got your email. Thanks!

Thomas

If you think about it, even stereo processing can't correct all problems. Most pop music has the bass instruments panned to the center. This goes back to LP days, but it's also good practice with CDs because that lets each loudspeaker share the load. So in that case you'd expect a "room correction" system to be calibrated with both the left and right speakers summed to mono. But if you then play some music where the bass is not exactly centered the calibration goes out the window. Add in three more speakers plus a subwoofer for surround sound, and these DSP devices have even less of a chance to do what they claim.

--Ethan

[barefoot]

Originally Posted by Ethan Winer

If you think about it, even stereo processing can't correct all problems.... Add in three more speakers plus a subwoofer for surround sound, and these DSP devices have even less of a chance to do what they claim.

One channel can correct at least one point in space (the useful spatial extent of that "point" is a function of the wavelength). Two channels can correct at least two points. It doesn't matter if signal is being shared between the two channels or not. So more channels gives more power to correct larger regions of space. A spherical shell of tiny speakers surrounding you could, in theory, correct or simulate any acoustic space.

Again, I'm far from being a proponent of room correction. I just want people to be clear about both its power and limitations.

Thomas

[The Byre]

DSP calibration in monitors is a bit like installing a bigger engine in your car to make up for the fact that the tires are flat.

[gainreduction]

With Genelecs autocal system you measure four points in the room, forming the sweet spot. A square of about 1x1 meters. You're not locked into one narrow position.

To me autocal or other room correction dsp's are just the regular bass and treble dipswitches on the back of nearfields taken one step further. You get 8 bands (Genelec) instead of bass and treble shelfs. Also you get eq settings based on accurate measurement instead of guesswork/by ear. How can it be worse ?

My room is well treated and sounds quite good. Had a little 125Hz bump and another around 2k, all within 3dB so not too bad. Also small 0.5 and 1dB bumps here and there. The Genelec 8240's took care of these for me and now my room sounds like a dream. I'm overwhelmed by their performance and mixing is more fun than ever.

Of course dsp should never be used as an excuse to not treat your room but if your room is already good then why not flatten out those last few bumps ?

[JesseJ]

I wouldn't trust a DSP for treating a bad acoustic enviroment.

And as far as considering the Genelecs, I would take a look at the Profels (link in my footer) as they are better (listening test clearly indicated that fact). There is no retailer in the US, but as spreakers/monitors are a 'for-life' thing, I would even consider spending a few hundred bucks on flying over, take a factory tour, meet the designer and buy a set. You will have them for the rest of your life.

I was convinced to the Profels in 5 seconds when I visited my friend who had a 2.0 system. Now I have a 5.1 system. I just had to hear them. I had the Genelec 8050s before...

[The Byre]

Originally Posted by gainreduction

. . . but if your room is already good then why not flatten out those last few bumps ?

Because those last few 'bumps' change according to where you are standing, how many people are in the room, whether the door is open or closed and a whole host of other things.

Pokey little nearfields in a rectangular room, with or without chunks of building materials and washing-up sponges nailed to the corners, will sound, well, the way they do. Some sort of 'super-calibration' system will not make things sound any better!

Or as Julie Andrews once sang

"Super-calibrate my speakers, still they sound atrocious!"

(Um diddle-iddle-iddle um, diddle-aye. Um-diddle-iddle-iddle-aye!)

[gainreduction]

Originally Posted by The Byre

Because those last few 'bumps' change according to where you are standing, how many people are in the room, whether the door is open or closed and a whole host of other things.

We actually tried all that while measuring.

- where you're standing: of course. That's why you measure and optimize the sweet spot. Or any other spot in the room and store it as a setting.

- how many people are in the room: This one was interesting. Hardly measurable difference between one and four persons in my small room.

- Door open or not: yes, difference. We calibrated mine to door-closed position since that's the normal state of operation in the multi-room facility I'm in.

But all of your concerns applies to any speaker, not just dsp ones.

[john caldwell]

Don't you think the issue of DSP corrections that are only a few inches wide is being exaggerated here? Bearing in mind that that wave lengths below 500 Hz exceed two feet, I'll guess that corrections, be them ones of simple amplitude or ones of time domain, should be good over a zone width related to wave length. So a correction aimed at 143 Hz (active room mode for an 8 foot ceiling) should be very good within 2 feet (90 degrees phase) of the sweet spot.

It's not until we get to 10KHz corrections that we get into fractions of an inch sweet spot width. I'd hardly call the 10KHz frequency band troublesome in a reasonably well treated room.

As gainreduction says, these principles of physics, width of the sweet spot, and plasticity of sweet spot with changes in room furniture, door position, etc; are principles that plague any playback system. So I'm hearing this argument as one which states that even though DSP corrections stun listeners with improvement, they are fadish, imperfect, and contrived...so let's go back to the old ways which are highly imperfect also.

I'm very appreciateive of all that Ethan's bass trap products have done for my room. Like others have said, I can't buy DSP monitior grooming as a substitute for mechanically-based room correction.

John-

[warhead]

Originally Posted by AndreH

Cool! This was verified by a response from Genelec today (though the Sweetwater dudes still insist it's only available in gold...must be trying to get rid of a few pairs in that color).

To my knowledge no dealer in the world has these speakers, so I doubt anybody from Sweetwater is trying to push a color on you. Genelec is only handling these DSP systems direct for now with no involvement from the dealer beyond a reference. If Sweetwater, Front End Audio or any other dealer refers you then Genelec is supposed to pay a commission to the dealer. This is until they get dealers educated about how to do the install etc.

That is the latest info I have.

War

[john caldwell]

Alto Music told me they sell the monitors when I inquired about the 8250. But they suggested that they must direct the customer to Genelec only for the calibration kit.

[Ethan Winer]

Originally Posted by gainreduction

With Genelecs autocal system you measure four points in the room, forming the sweet spot. A square of about 1x1 meters. You're not locked into one narrow position.

They can measure in 400,000 places in the room and there's still no way for one EQ setting to improve a usably wide area.

if your room is already good then why not flatten out those last few bumps?

Below 50 or 60 Hz I agree. But certainly not at higher frequencies.

The article I mentioned earlier is going to be on the RealTraps site either later today or tomorrow morning. Look for a small heading "Stereophile Readers" on our home page. I promise it will be a real eye-opener.

--Ethan

[Ethan Winer]

John,

Originally Posted by john caldwell

Don't you think the issue of DSP corrections that are only a few inches wide is being exaggerated here? Bearing in mind that that wave lengths below 500 Hz exceed two feet, I'll guess that corrections, be them ones of simple amplitude or ones of time domain, should be good over a zone width related to wave length.

If I didn't have solid proof I wouldn't be making such statements.

Outdoors 100 feet in the air, away from all boundaries, your assessment about wavelengths is correct. But as soon as you put a sound source in a room the peaks and nulls can change drastically over very small distances. The intent of this article is to address a different issue, but the three graphs there show how the response changes in a room versus distance:

http://www.ethanwiner.com/believe.html

--Ethan

[gainreduction]

Originally Posted by warhead

To my knowledge no dealer in the world has these speakers

I got mine from my regular go-to music shop. The calibration was done by Genelec. (I'm in Sweden)

I don't want to argue about room correction with anyone. All I know is that my monitoring improved greatly with the dsp-Genelecs, upgraded from non-dsp Genelecs. My annoying 125Hz bump is gone and I couldn't be happier about it. The phantom center image has improved greatly and I can hear phase relationships like never before.

My room (well treated, sound ok) would have needed a total $30K rebuild to achieve the same or close to the same improvement. I'm very happy I could solve it with $3k monitors. To each his own.

[gainreduction]

Originally Posted by Ethan Winer

They can measure in 400,000 places in the room and there's still no way for one EQ setting to improve a usably wide area.

FWIW, the eq settings are individual for each speaker.

Ethan, since you're bashing dsp monitors I'd like to know If you actually have heard the Genelec product you're advocating against ? Have you measured the outcome and proved that dsp made the room perform worse ?

[The Byre]

"Super-calibrate my speakers,
Try to get in focus.
Hoping that the sound of them
Is something quite precocious!
If you measure long enough
The room will just sound bogus.
Super-calibrate my speakers
My mix sounds atrocious!"

Um diddle-iddle-iddle um, diddle-aye.
Um-diddle-iddle-iddle-aye!

(I'm in one of those long editing sessions where the mind starts to wander!)

[GYang]

Originally Posted by jdjustice

[list]


the new list:

• Genelec 8240A
• Tannoy Precision 6 iDP
• Focal SM8

~j.d.

I heard only expensive K+H system with DSP and it was impressive.
It was installed in almost ideally treated room and some further improvements were achievable.
It's not cure for bad room definitely, it can change things for better, but first task is to have correct listening environment (at least to degree to match good quality monitors).
I would not recommend DSP equipped monitors if they are not absolutely top notch (excellent converters and fast processing) for reasons mentioned in some posts.
Anyhow IMO high-end monitors with digital inputs, great DACs (and I assume analogue volume constrol built-in before power amps) could be real problem solvers, especially in surround systems. But price as always might be very restricting.

[Ethan Winer]

Folks,

Originally Posted by Ethan Winer

The article I mentioned earlier is going to be on the RealTraps site either later today or tomorrow morning. Look for a small heading "Stereophile Readers" on our home page. I promise it will be a real eye-opener.

Okay, this is now on the RealTraps site:

http://www.realtraps.com/art_audyssey.htm

--Ethan

[feck]

I have a set of MM27s on the way. I am in the bottom floor of a house, which of course has acoustical problems. I am planning to have the room treated to the fullest extent I am able (I rent, don't own) and am assuming (not sure) that I won't be able to correct ALL problems. So, the question I have is - should I be prepared to use SOME sort of EQ to even out the problems I am unable to fix acoustically? If so, is there a benefit to using a hardware outboard EQ vs. a digital ITB EQ for this purpose? Just trying to plan out my course of action and prepare for what may be another significant hardware investment if need be. Ethan, I am planning to contact you anyhow regarding the treatment, so any overview-style advice here would be greatly appreciated.