THX Certified products

[3db]

I would like to know the cost benefit of this certification to the consumer. I can't help but think that its a bit of consumer fleecing going on as there are many products out there that are not THX certified and can perform well beyond the THX specs. THX is coming across liek ISO9002 certification.. it was big thing with much money spent on getting certified and then it all just sort of fizzled away.

 

[Seth=L]

I think you answered your own question. There is not benefit, only cost. George Lucas and whomever works for THX seem to be the only beneficiaries.

 

[Alex2507]

I have an old THX Select rec'r. I notice two things that I like over my other old non THX rec'r.

1. +10 db boost on subwoofer analog input

- It allows me to calibrate at a higher matched reference level for multiple sources.

2. 24 db/octave crossover slope as opposed to 12/db/octave.

- Hopefully this will make my subs less localizable in a nearfield placement.
(I'll get back to you on this ... like after I move them for the bazillionth time.)

3. There is no #3 but with as much money as you have,
why don't you just buy one of each and tell us the score?

 

[lsiberian]

I had one of those and it was better than the receiver I have now. Besides I like the idea that I have something certifiable other than the certificate from the institution.

 

[KEW]

I would like to know the cost benefit of this certification to the consumer. I can't help but think that its a bit of consumer fleecing going on as there are many products out there that are not THX certified and can perform well beyond the THX specs. THX is coming across liek ISO9002 certification.. it was big thing with much money spent on getting certified and then it all just sort of fizzled away.

Lots of certifications have panned out that way. It will be interesting to see how soon it fades away. At the time it was initialized, the need was probably greater than now. It also helped establish some standardization (like 80Hz roll-off for mini-surrounds) with-in the industry which I believe has been beneficial to the consumer by increased compatibility between manufacturers and components.

It is still nice to know that a THX unit meets some established minimum performance goal and can be comfortably bought by someone who wants assurance of reasonable quality. However, if you are willing to do a little research, I agree that you can find equivalent for less $.
I would be comfortable telling someone wanting to pick up a cheap used receiver off of Craig's list to use THX cert as a quick and dirty way to know it isn't a POS.

 

[JerryLove]

THX isn't simply about minimum performance.

THX is about getting a consistant sound, both in sound level and in timbre. Being "good" is less important here than being "consistant".

THX was originally designed for theaters, the problem, which was real, was that a soundtrack would sound one way in theater A and another in theater B. Mixing was a nightmare because of that.

The point was to make all theaters so similar in how they reproduced sound that a movie would sound the same in any theater. This gave the movie producer (sound guy / director) control over the end result that he did not have before.

THX in the home is after the same goal.. not the best quality (though there are certainly minimums there), but consistant reproduction.

And THX works on the production side too... it controls a great deal of how mixing occurs, enforcing rules that allow (for example) dialog modes in equipment.

It's laudable, in my opinion.

 

[3db]

Ok

I understand what THX does in the recording end and for most part Home Theater equipment. However, I can still assemble a non THX based system that would surpass in performance (at least from an audio perspective) THX certified equipment for cheaper. I don't know enough about video to do the same which relates directly to my next paragraph.

KEW, you did bring up a good point. For those who do not want to research the equipment they are going to be buying, THX certified is a safe route to go.

Alex, I suspect that your older non THX receiver in ability to fine tune your sub cuto ver frequnecy was more of a fucntion of the age of the receiver and not because its THX certified. Look at the Yamaha receivers. They are not THX certified and you can fine tune the sub cut off frequency.

 

[MatthewB.]

I have an older Denon 4802 THX Ultra2 reciever and what I loved about it was it's THX post processing sound to multichannel audio. I also have an THX Ultra2 Onkyo 805 that does an excellat job of THX post processing with multichannel audio. I also have a Denon 3808ci that has NO!!!! THX certification whatsoever and guess what, yep it does a great job of Dolby Prologic IIx post processing of multichannel audio.

 

[Alex2507]

I have an older Denon 4802 THX Ultra2 reciever and what I loved about it was it's THX post processing sound to multichannel audio. I also have an THX Ultra2 Onkyo 805 that does an excellat job of THX post processing with multichannel audio. I also have a Denon 3808ci that has NO!!!! THX certification whatsoever and guess what, yep it does a great job of Dolby Prologic IIx post processing of multichannel audio.

When I think of multi channel audio I think of the 6 Channel Analog Audio Inputs. You threw me when you mentioned Prologic IIx. Correct me if I'm wrong but that's a 7.1 DSP applied to stereo ... or maybe the matrixing of 5.1 to 7.1?

If you are talking about what a THX rec'r specifically does to 6 channel in, I'm interested. I'd like to see it in black and white (link) again or just have it explained again ... in short I'd like a refresher.

2. 24 db/octave crossover slope as opposed to 12/db/octave.

- Hopefully this will make my subs less localizable in a nearfield placement.
(I'll get back to you on this ... like after I move them for the bazillionth time.)

Almost forgot about this. Before when I had only one sub in nearfield placement I did not like it on either side of the listening position with the 12 db/octave slope. Now that I have two subs (one on each side of the listening position) with the 24 db/octave slope I am really liking it.

I can't wait until tomorrow ~11:00 AM so that I can really crank the living snot out of it.

THX RULES !!!

 

[jostenmeat]

When I think of multi channel audio I think of the 6 Channel Analog Audio Inputs. You threw me when you mentioned Prologic IIx. Correct me if I'm wrong but that's a 7.1 DSP applied to stereo ... or maybe the matrixing of 5.1 to 7.1?

PLIIX can matrix anything to 7.1, whether mono, stereo, 5.1, so far as I know.

If you are talking about what a THX rec'r specifically does to 6 channel in, I'm interested. I'd like to see it in black and white (link) again or just have it explained again ... in short I'd like a refresher.

I have never once heard of any processor that could take the 6ch analogs, and matrix them. That doesn't mean it doesn't exist, but I haven't seen it yet. This was perhaps the most important reason for me to get the HDMI audio upgrade over mch analogs (before I purchased my Onkyo 805 as processor). A close second was the flexibility of bass mgmt.


edit: Back to THX, in my own wanderings, it was with video that I usually desired THX the most, with THX mode. If there is a THX mode on a display, it will be the most accurate overall, and I haven't heard of a single exception yet. Of course, it looks too dim for many, but that's because there are many who watch in either daylight or with the lights on. I have been taught here that THX mode is always the go-to mode to start with for any pro calibrator.

 

[Alex2507]

I have never once heard of any processor that could take the 6ch analogs, and matrix them.

Me neither. I'm just getting my mind around the idea that you can take stereo, fiddle with it and call it MCM. I'm more focused on the source being MCM but that's just me.

Anyway, what THX does with audio is this: (stolen from the web)

"The THX 80 Hz crossover features a 4th order low pass to the sub and a 2nd order high pass to the mains, which when compounded by a THX speaker's own 2nd order rolloff, sums a perfect flat response with the least amount of phase shift."

I like knowing it does that. It enables me to make informed placement decisions but that info is rather elusive. Still, that linked article had more info than I was ready to process. There's more info to keep track of in this hobby than I ran into in all 3 years of grade 9.

Alex, I suspect that your older non THX receiver in ability to fine tune your sub cuto ver frequnecy was more of a fucntion of the age of the receiver and not because its THX certified. Look at the Yamaha receivers. They are not THX certified and you can fine tune the sub cut off frequency.

The rec'rs are the same vintage. 2002 and 2003 I believe. You can select the crossover slope in the rec'r?

 

[jostenmeat]

"The THX 80 Hz crossover features a 4th order low pass to the sub and a 2nd order high pass to the mains, which when compounded by a THX speaker's own 2nd order rolloff, sums a perfect flat response with the least amount of phase shift."

Good stuff Alex.

Hmm, you know I'm pretty sure mine is at "THX"/80 for most speakers, and I don't think there is anything I could do about getting rid of the THX logo on the xover menu when 80 is selected (I have to double check).

So . . . if I have it at 60, for say the mains, or 100 for say some surrounds, can I presume that the high pass is still just 2nd order . . . or not . . . hmmm . . . .

I would like to try a 4th order high pass to my front three for experimentation, but I'm sort of doubting that I even have that option . . .

After all, my PSBs are not THX certed so far as I know.

 

[MatthewB.]

Josten, when you use THX recievers that say have Audyssey and say Audyssey selects your crossover at 60 (below THX recommended 80) it will still be in THX post processing, but using Audysseys calibrations as fine tuning. But say Audyysey selects 80Hz as the crossover of your speaker and you choose 60 Hz, then the calibration from Audyssey will only go down to 80 and not any further (like a brick wall) but will still have the THX processing.

I look at the THX selection processing as like washing a car, while Audyssey is the turtle wax applied afterwards....just better.

Also Josten, speakers don't have to be THX certified, they just have to meet certain qualifications, it's just some speaker companies choose not to get THX certification basically because on most speakers it's pointless. Trust me my Deftech speakers morethan meet THX certification, in fact they probably beat em, but DefTech chose not to get that badge which would increase the cost. So as long as your PSB speakers can achieve 80hz with littel distortion at certain frequencies, then they meet THX guidelines.

 

[jostenmeat]

Josten, when you use THX recievers that say have Audyssey and say Audyssey selects your crossover at 60 (below THX recommended 80) it will still be in THX post processing, but using Audysseys calibrations as fine tuning. But say Audyysey selects 80Hz as the crossover of your speaker and you choose 60 Hz, then the calibration from Audyssey will only go down to 80 and not any further (like a brick wall) but will still have the THX processing.

Yes. To make things more complicated, the implementation of Audyssey can vary, and is definitely not always done so to the wishes of Audyssey. For example, Onkyo will define your speaker as full-range if the F3 is detected to be below 80hz. Therefore, even if 60hz should be the desired xover point, I don't think it matters, and Audyssey will be applied no matter the point chosen?

Also Josten, speakers don't have to be THX certified, they just have to meet certain qualifications, it's just some speaker companies choose not to get THX certification basically because on most speakers it's pointless. Trust me my Deftech speakers morethan meet THX certification, in fact they probably beat em, but DefTech chose not to get that badge which would increase the cost. So as long as your PSB speakers can achieve 80hz with littel distortion at certain frequencies, then they meet THX guidelines.

Right, ok, but your explanation actually can be construed as an argument for trying a steeper slope. If my speaker exceeds THX in terms of extension, then the natural roll off + 2nd order slope may no longer be an approximation of a 4th order slope. See? Instead would I be suffering unnecessary midbass bloat? I dunno, but it would be fun to play around with slopes.

I guess I just try to trust in letting Audyssey do its thing. They know more than I do. After all, it sounds better with it on than off. I thought the improvement was approximately to the same level as applying significant treatments, and I say that after having the panels in for a number of months before using the tech.

Thanks.

 

[JerryLove]

Also Josten, speakers don't have to be THX certified, they just have to meet certain qualifications, it's just some speaker companies choose not to get THX certification basically because on most speakers it's pointless. Trust me my Deftech speakers morethan meet THX certification, in fact they probably beat em,

You seem to have fallen into the trap of believing the issue is "quality".

THX reference level, as an example, is designed to regulate the listening volume of the various tracks at a given amplifier setting ("0"). If your speaker is "better" in that it is "more efficient" then it will be too loud and fail the THX standard.

It is true that you do not need to have a THX certification to have a THX compliant piece of hardware; but it's just not as simple as "this good or better".

 

[MDS]

THX reference level, as an example, is designed to regulate the listening volume of the various tracks at a given amplifier setting ("0"). If your speaker is "better" in that it is "more efficient" then it will be too loud and fail the THX standard.

THX can't regulate volume differences between different tracks. If the receiver is calibrated using the THX standard -30 dB test tone, the output SPL at '0' will be far greater than 'reference level' if playing a track whose average level is greater than -30 dB. For example, a CD with an average level of -12 dB will be +18 dB louder at that same '0' volume setting when an audio sample peaks.

Once calibrated, the sensitivity of different speakers is irrelevant. In order to achieve the reference level, the channel trims were adjusted so that each channel is about equal. A more sensitive speaker will simply require lower numbers on the channel trims - either less boost or more cut. In other words, if an 87 dB sensitivity speaker needs say +4 dB boost on the channel trim, a 90 dB speaker would only require +1 dB boost.