Sennheiser HD650 Review (Headphone)

[Jimbob54]

Out of curiosity, have you heard/owned the Philips X2HR? I don't think my ears are mammoth, however I've had problems with over-ear headphones that didn't really cover everything, or had hard plastic resting against the ear. The Philips earpieces are the most capacious I can recall, sound decent, don't seem to require much power.

I haven't, no. Keep debating trying a pair. But the cabinet is full so it's dead man's shoes now.

 

[maverickronin]

Out of curiosity, have you heard/owned the Philips X2HR? I don't think my ears are mammoth, however I've had problems with over-ear headphones that didn't really cover everything, or had hard plastic resting against the ear. The Philips earpieces are the most capacious I can recall, sound decent, don't seem to require much power.

I'd say comfort is above average if they are anything like the original X2's.

 

[Dreyfus]

The X2HR's comfort is actually quite good. As an orientation: the pads are very similar in size and stiffness to those of my Q701. The shape is more edged and less round, though. That might add more contact surface, hence improve the seal. As another comparison: the pads are thicker and stiffer than my Beyer DT 880 BE's and DT 990's , which are rather round and soft.

If you have trouble with the ears touching the plastic grill of the driver, you can shove a thin stripe of foam or a rolled-up piece of tissue under the ring of the pad on the inside. Works very well with my Beyer DT 880 / 990 and my slightly protruding pinnas.

I also like the comfort of the Sennheiser HD 6** series. Their soft headbands are my standard replacement piece when modding other headphones for comfort. The earpads are okay. Maybe a bit too thin for my taste on the long run. I generally prefer thicker pads that adjust better to my head shape + spectacle frame (improve the seal) and are little bit more forgiving when wearing out.

 

[Toroid]

Dang! The 650s with the EQ sounds like a whole new headphone. Thanks Amir!

 

[thewas]

So they built their own pliable one. Subsequent to that GRAS produced their own version of this but per above, we don't have the preference curve for it. Differences are probably not large but we better not auto-generate EQ against the Harman curve with high precision.

I fully agree, on the other hand for example your quite sharp and very high frequency 13700 Hz Gain -3.5 dB Q 4.0 PEQ which you made vs the Harman target (which of course isn't fully valid on your rig) is imho a bit of a counter example.

 

[Feelas]

No wonder you say that the your headphones and loudspeakers equalised to the corresponding Harman targets sound tonally very similar.
This not so small bass hump was though chosen for both by taste and listening to few recordings which imho don't even represent the current state of art of a good recording in 2020 and continue thus audios circle of confusion which Olive criticises himself and are the biggest problems and flaws of the Harman targets and making it different to a neutral loudspeaker placed and room EQed optimally in an acoustically good room. If we look for example the bass target of Genelec and Neumann room corrections it is rather flat and could explain the opinions of several posters in this and other threads that don't like the Harman target especially in the bass, although it may work quite well especially for older and poorer recordings that were mixed using monitors without room correction.

It might just mean, that some customer gruops prefer brighter than the reference sound, for whatever reason they have. Duh. Some like overtly clear gear and there's nothing wrong with that, yet overtly clear makes some recording compromises come out-loud, while detracting from what engineer chose to highlight. That's not reference, far from that. If one wanted to highlight the movie reel artifacts, one would end up with absolutely mangled movies.

It's terrible how much the whole target curve game turned into "I'm right" shouting match. Just curious: wouldn't monitors w/ room corrections have you mix into un-flat, room-like EQ? You'd end up running engineering using an unrealistically bass-shy sound (which omits the room-gain effects & stuff) and overestimate for clarity that just isn't there when faced with the room. Since B&T (BLT?) are perceived relatively, it's impossible to make a properly bright mix if you miss realistic bass levels. I think everyone should have at least basic mixing experience to see how balancing out the sound is a hard & fragile game of scales and if even one piece is missing, the whole idea is ripped.

Let's just face it and hopefully agree: it's impossible to make universal recordings, unless everyone turns into buying flat monitors & runs deadened rooms, or some other standard.

And anyways, if one read Toole's work on assessing speaker performance in blind-testing situations, people tend to select the flattest & most accurate speakers if asked what plays the best, no matter the experience & the else. Yet, obviously, in the Internet it's known that the mass customer is always a moron. Uhhh...

edit: I think the phenomenon of the missing fundamental should be taught in audiophile school It's the perfect illustration of how flawed our hearing is, how our mind "just makes up" a sound, and only a partial understanding of physics gets one into justifying one's spending habits (e.g. My speakers need to reproduce 16Hz in order to play piano solos).

It is easy to hear the missing body of instruments that you know sound different. Massively annoying to have thin recordings.

 

[Robbo99999]

Question: what is "diffuse field EQ"?

I used Oratory's Diffuse Field EQ from here for the HD600, I found out I didn't like headphones EQ'd to that curve (Solderdude answered you on some other specifics of Diffuse Field already):
https://www.dropbox.com/s/upib5ztmte79qpl/Sennheiser HD600 (Diffuse Field).pdf?dl=0

I do however use his measurements to create my own EQ for the HD600 which I EQ to the Harman Curve, he also of course includes a Harman Curve EQ for each headphone he measures, here's Oratory's HD600 Harman Curve EQ:
https://www.dropbox.com/s/dm0m6u3s3b4zqzl/Sennheiser HD600.pdf?dl=0
and here's the HD650 Harman Curve EQ:
https://www.dropbox.com/s/zr5tqw0qojom9uh/Sennheiser HD650.pdf?dl=0

 

[thewas]

By the way Oratory now provides for some headphones also an EQ to target without the Harman bass boost he calls "Optimum Hifi Curve", here for example for the H600 https://www.dropbox.com/s/ygs3wfnj4ntgmhq/Sennheiser HD600 (Optimum HiFi Curve).pdf?dl=0 vs the Harman one https://www.dropbox.com/s/dm0m6u3s3b4zqzl/Sennheiser HD600.pdf?dl=0

 

[Jimbob54]

I used Oratory's Diffuse Field EQ from here for the HD600, I found out I didn't like headphones EQ'd to that curve (Solderdude answered you on some other specifics of Diffuse Field already):
https://www.dropbox.com/s/upib5ztmte79qpl/Sennheiser HD600 (Diffuse Field).pdf?dl=0

I do however use his measurements to create my own EQ for the HD600 which I EQ to the Harman Curve, he also of course includes a Harman Curve EQ for each headphone he measures, here's Oratory's HD600 Harman Curve EQ:
https://www.dropbox.com/s/dm0m6u3s3b4zqzl/Sennheiser HD600.pdf?dl=0
and here's the HD650 Harman Curve EQ:
https://www.dropbox.com/s/zr5tqw0qojom9uh/Sennheiser HD650.pdf?dl=0

Genuine question re yours and oratory hd600 eq. Youve said before because youre not limited to 10 points, yours hugs closer than his. I assume you've A/B between yours and his? If so, can you honestly hear a difference? There can't be more than a couple of dB variance at most, so assume playing around 85 to 90 dB, is a couple of d/B at a couple of frequency areas audible?

 

[Robbo99999]

Genuine question re yours and oratory hd600 eq. Youve said before because youre not limited to 10 points, yours hugs closer than his. I assume you've A/B between yours and his? If so, can you honestly hear a difference? There can't be more than a couple of dB variance at most, so assume playing around 85 to 90 dB, is a couple of d/B at a couple of frequency areas audible?

I've never done any proper controlled testing in any of my listening tests (although I do try to level match), but do indeed listen carefully on sections of my favourite tracks when I make EQ's or try anyone else's and quickly flip between EQ A&B to make comparisons on short sections of tracks taking note of areas where I can hear differences. Sometimes I manage to hug the curve closer using less filters than Oratory, eg on the HD600 for instance:
(note this is the HD600, and not the HD650 which is the subject of this review, so don't try this on your HD650 if you're reading this).

That's 7 filters vs his 10 filters, I think he likes to stick to 10 so that he can use High & Low Shelfs that can be tweaked easily by the end user to taste, otherwise he could probably have gotten away with using less in this particular case. I don't like using a Low Shelf on the bass because I don't believe in leaving the bass significantly boosted at around 20Hz and below (especially with open backed headphones) - I prefer to use a Peak Filter for the bass that has a natural roll off, in the bid to minimise distortion, which can be troublesome on the bass of the HD600 for instance. To me by using a Peak Filter I can still have my bass and eat it (cake & eat it).

Sometimes I use more than 10 filters to EQ accurately to the curve, but as Oratory & others say - don't EQ accurately above 10kHz because the measurement is too unpredictable up there, so I don't do that either. I am of the belief that a smooth frequency response up to 4kHz is particularly important as the measurements are more reliable in the 20Hz-4kHz area than the rest of the range (and certainly to 1kHz), so I do really try to EQ a smooth curve up to that point (& will use more filters if necessary in order to achieve that).

I tend to EQ my headphones myself because I enjoy creating the EQ's and I like being able to customise them through listening, etc.

 

[Jimbob54]

I've never done any proper controlled testing in any of my listening tests (although I do try to level match), but do indeed listen carefully on sections of my favourite tracks when I make EQ's or try anyone else's and quickly flip between EQ A&B to make comparisons on short sections of tracks. Sometimes I manage to hug the curve closer using less filters than Oratory, eg on the HD600 for instance:
View attachment 102427
That's 7 filters vs his 10 filters, I think he likes to stick to 10 so that he can use High & Low Shelfs that can be tweaked easily by the end user to taste, otherwise he could probably have gotten away with using less in this particular case. I don't like using a Low Shelf on the bass because I don't believe in leaving the bass significantly boosted at around 20Hz and below (especially with open backed headphones) - I prefer to use a Peak Filter for the bass that has a natural roll off, in the bid to minimise distortion, which can be troublesome on the bass of the HD600 for instance. To me by using a Peak Filter I can still have my bass and eat it (cake & eat it).

Sometimes I use more than 10 filters to EQ accurately to the curve, but as Oratory & others say - don't EQ accurately above 10kHz because the measurement is too unpredictable up there, so I don't do that either. I am of the believe that a smooth frequency response up to 4kHz is particularly important as the measurements are more reliable in the 20Hz-4kHz area than the rest of the range (and certainly to 1kHz), so I do really try to EQ a smooth curve up to that point (& will use more filters if necessary in order to achieve that).

I tend to EQ my headphones myself because I enjoy creating the EQ's and I like being able to customise them through listening, etc.

Thanks, but I'm not sure that answered my question. When you A/B yours and his, do you notice a difference on hd600?

 

[Robbo99999]

I'm not sure that answered my question. When you A/B yours and his, do you notice a difference on hd600?

I can't remember if I did that, because it was a long time ago.....but you've got my reasoning behind my EQ's as a related bonus. But on the topic of Low Shelf Bass boost vs using Peak Filters on the bass, then of course I have heard the differences in that situation, but that is mostly between my own EQ's.....so I can tell you I've noticed a difference on that specific, which is a point of difference between Oratory's & my approach and so answers your question indirectly.

 

[Aperiodic]

Amir, re comment on the 'plasticky' feel: Some of the parts (such as the baffles the speaker elements mount on) are actually carbon fiber, not traditional plastic.

I owned the 650 and its ancestor the 580. Although it's the headphone that many audiophiles 'love to hate', it's a classic design that has stood the test of time in the fickle audio world and is still 'in the hunt' in its price bracket, although IMO it is bettered by the Beyer Amiron Home I upgraded to.

 

[amirm]

Amir, re comment on the 'plasticky' feel: Some of the parts (such as the baffles the speaker elements mount on) are actually carbon fiber, not traditional plastic.

Ah, good to know. As I noted in the review, I did have the 5 series years back when it was the standard in major music labels. It may have been the 580.

 

[bobbooo]

For anyone interested, some more info about Oratory as requested. Like I said in this post, he is a professional acoustic (and field application) engineer who has worked in acoustic R&D (including extensive headphone measurements of course) and designing transducers as part of the company he works for (which includes some ex-AKG employees who he works with). He has degrees in both Technical Physics, and Energy & Measurement Technology, the latter a master's (MSc), with specialization in acoustics and psychoacoustics. He is also a musician, music creator and recording artist and former audio engineer with his own recording studio, so he knows intimately both sides of the audio production / reproduction chain, the close matching of these two sides in terms of sound heard being paramount in achieving high fidelity sound reproduction (including in headphones). Oh and according to Harman's classifications he's also a trained listener, passing level 8 of their How to Listen software, which he's said he actually didn't find that hard and didn't attempt higher levels, so his ability could be even better than this.

As for his equipment and methodology, his rig is the closest commercial analogue to that which Harman used when developing their target and preference formula, so is most likely to accord with their results of the ones publicly available to consumers. By coupler, I was specifically talking about the GRAS RA0045 Oratory uses (the exact same one Harman used, unlike the RA0402 used on here and by Crinacle), not including the anthropometric pinnae, which were custom made by Harman but for which the pliable GRAS KB5000/5001 used by Oratory are a good analogue "that more accurately measures leakage effects of humans" according to Harman. Here he describes his measurement process:

I measure at 5 positions (ctr, up, down, front, back) with multiple reseats.
I also forcibly break the seal on some reseats, to see how it affects this particular headphone.

For headphones with little variation I take the average.
For seal-dependent headphones (where some individual reseats would have a much lower bass response) I take the average of the best-sealing individual results at low frequencies and cross over to a total-average of all measurements somewhere in the mid-range (where the seal stops having an effect).

And here his averaging and preference rating calculation methodology (posted earlier in this very thread by @MZKM in response to asking him about this):

I calculate at 500 pts from 10-20k. Mostly because we use this format for all our measurements. A higher resolution does not make sense in the context of headphone measurements (see measurement variation)

Harman themselves calculate in the model with 121 points spaces logarithmically from 20 Hz to 20 kHz.

Assuming that channel matching is good enough, I average l+r channel and calculate from there.
For multiple units I calculate the rating for every unit and average the ratings.

So:
1. channel avg
2. calculate rating
3. unit avg

The order is not crucially important though, as long as channel matching is high and unit variation is low.

As for his EQ profiles, they are not auto-generated. He does them manually based on his measurements, aiming for the Harman target but checking for non-minimum phase parts of the frequency response that cannot be effectively EQed, making sure post-EQ distortion is below audible levels, considering sealing issues, as well as carefully listening to the headphones and making fine-tune adjustments by ear if necessary of course.

I hope everyone now understands why I recommend his measurements and EQ profiles over any others. I'm not aware of any other resource that offers hundreds of freely available headphone measurements and EQ profiles using the closest commercial analogue of Harman's equipment, made by someone with as high a level of specific professional expertise in measuring headphones combined with a broader body of experience and knowledge of both the production and reproduction ends of the audio chain, all for zero commercial or competitive benefit (e.g. website traffic metrics) or 'success' / fame (he remains anonymous after all), just doing it out of pure passion for headphones and a desire to spread truth about the science of audio. If anyone wants to know more details about him, his methodology, or advice on how to professionally measure headphones, they can send him a (polite) DM on Reddit, and I'm sure he'll give a detailed, thoughtful reply (as he did for MZKM and has done in the past for me and countless others on Reddit).

I am not comfortable giving his real name or other identifiable details over the internet without his permission (this could also be classed as doxing, which is actually illegal in some countries). Everyone should have the right to online privacy. As for the companies he's designed transducers for, that's under NDAs, as he says in this very interesting and enlightening interview / discussion hosted by headphones.com:

And here's part 2 in which the also highly knowledgeable @Mad_Economist joins them halfway through:

Just a bunch of nice, rational guys passionate about headphones having an informed, cordial discussion about audio, free from any aggro, competitiveness or tribalism. How refreshing

 

[Newman]

It might just mean, that some customer gruops prefer brighter than the reference sound, for whatever reason they have. Duh. Some like overtly clear gear and there's nothing wrong with that, yet overtly clear makes some recording compromises come out-loud, while detracting from what engineer chose to highlight. That's not reference, far from that.

“Duh”? The whole point of the research is telling us that different customer groups do not have different sound preferences, unless they have severe hearing damage. There have not been shown to be any “customer groups that prefer a brighter (/duller) reference sound, for whatever reason”.

The whole point is telling us the entirely logical and, when you think about it, completely unsurprising outcome of all the listening tests is that we actually want a reproduction device to reproduce accurately, i.e., with tonality very similar to the original instrument or band. Brighter, or darker, will sound wrong because we know what the original sound of a voice or an instrument is like. For a reproduction device, we expect nothing different.

What we do have, is different musical preferences. You might prefer brighter sounding music, or someone might prefer more bass oriented music. But when it comes to reproducing it, we do not have such wide ranging variations in our preferences.

The sole exception, if our hearing is generally okay-ish, is the amount of bass, where we tend to vary and need to set up our home system ‘to taste’. But this is all coming from the research, anyway, so it is not inconsistent. And the research information about appropriate target curves shows a range of bass level adjustment, typically below about 100 to 130 Hz, that can be adjusted from approximately flat to approximately plus 6dB, according to personal taste. So again, there is no dictatorial attitude to one right target curve.

Just curious: wouldn't monitors w/ room corrections have you mix into un-flat, room-like EQ? You'd end up running engineering using an unrealistically bass-shy sound (which omits the room-gain effects & stuff) and overestimate for clarity that just isn't there when faced with the room.... Let's just face it and hopefully agree: it's impossible to make universal recordings, unless everyone turns into buying flat monitors & runs deadened rooms, or some other standard.

Disagree. A professional sound engineer, who knows what he or she’s doing and wants to work to high standards, will mix at the mixing desk, and master in a mastering room. The mastering room is reasonably representative of the home listening environment. It is not dead. An example:

Final mastering is done here, with high quality speakers possessing an extended, flat frequency response and well controlled dispersion, and the engineer should have the bass equalisation of the room tailored to match his own personal preference for bass level, so that he feels comfortable when it is right. Then, when you play the mix back at home, you have the room bass equalised in your room to the level that matches your preferences. Then the bass will sound right for you too. It is possible to close the loop. It is not futile.

(As an aside: A real risk is the rise of the home studio, where the musician composes and creates his or her music at home, then produces at home, then publishes it for sale. There will be many instances where this home studio production work is of a low standard and perhaps is entirely done at a mixing desk. But that’s a different issue. People who are trying to do it properly and professionally are not doing that.)

cheers

 

[Robbo99999]

For anyone interested, some more info about Oratory as requested. Like I said in this post, he is a professional acoustic (and field application) engineer who has worked in acoustic R&D (including extensive headphone measurements of course) and designing transducers as part of the company he works for (which includes some ex-AKG employees who he works with). He has degrees in both Technical Physics, and Energy & Measurement Technology, the latter a master's (MSc), with specialization in acoustics and psychoacoustics. He is also a musician, music creator and recording artist and former audio engineer with his own recording studio, so he knows intimately both sides of the audio production / reproduction chain, the close matching of these two sides in terms of sound heard being paramount in achieving high fidelity sound reproduction (including in headphones). Oh and according to Harman's classifications he's also a trained listener, passing level 8 of their How to Listen software, which he's said he actually didn't find that hard and didn't attempt higher levels, so his ability could be even better than this.

As for his equipment and methodology, his rig is the closest commercial analogue to that which Harman used when developing their target and preference formula, so is most likely to accord with their results of the ones publicly available to consumers. (By coupler I was specifically talking about the GRAS RA0045, not including the anthropometric pinnae, which were custom made by Harman but for which the pliable GRAS KB5000/5001 used by Oratory are a good analogue "that more accurately measures leakage effects of humans" according to Harman). Here he describes his measurement process:


And here his averaging and preference rating calculation methodology (posted earlier in this very thread by @MZKM in response to asking him about this):



As for his EQ profiles, they are not auto-generated. He does them manually based on his measurements, aiming for the Harman target but checking for non-minimum phase parts of the frequency response that cannot be effectively EQed, making sure post-EQ distortion is below audible levels, considering sealing issues, as well as carefully listening to the headphones and making fine-tune adjustments by ear if necessary of course.

I hope everyone now understands why I recommend his measurements and EQ profiles over any others. I'm not aware of any other resource that offers hundreds of freely available headphone measurements and EQ profiles using the closest commercial analogue of Harman's equipment, made by someone with as high a level of specific professional expertise in measuring headphones combined with a broader body of experience and knowledge of both the production and reproduction ends of the audio chain, all for zero commercial or competitive benefit (e.g. website traffic metrics) or 'success' / fame (he remains anonymous after all), just doing it out of pure passion for headphones and a desire to spread truth about the science of audio. If anyone wants to know more details about him, his methodology, or advice on how to professionally measure headphones, they can send him a (polite) DM on Reddit, and I'm sure he'll give a detailed, thoughtful reply (as he did for MZKM and has done in the past for me and countless others on Reddit).

I am not comfortable giving his real name or other identifiable details over the internet without his permission (this could also be classed as doxing, which is actually illegal in some countries). Everyone should have the right to online privacy. As for the companies he's designed transducers for, that's under NDAs, as he says in this very interesting and enlightening interview / discussion hosted by headphones.com:

And here's part 2 in which the also highly knowledgeable @Mad_Economist joins them halfway through:

Just a bunch of nice, rational guys passionate about headphones having an informed, cordial discussion about audio, free from any aggro, competitiveness or tribalism. How refreshing

I find that an impressive repertoire of skills & testing methodologies, kudos to Oratory for his abilities and his contribution to the headphone world.

 

[amirm]

As for his equipment and methodology, his rig is the closest commercial analogue to that which Harman used when developing their target and preference formula, so is most likely to accord with their results of the ones publicly available to consumers. (By coupler I was specifically talking about the GRAS RA0045, not including the anthropometric pinnae, which were custom made by Harman but for which the pliable GRAS KB5000/5001 used by Oratory are a good analogue "that more accurately measures leakage effects of humans" according to Harman). Here he describes his measurement process:

Then I was correct that his setup is not the same as Harman's. Nor is it any better than what I am using. You put his setup on a pedestal as if the situation is different.

For anyone interested, some more info about Oratory as requested. Like I said in this post, he is a professional acoustic (and field application) engineer who has worked in acoustic R&D (including extensive headphone measurements of course) and designing transducers as part of the company he works for (which includes some ex-AKG employees who he works with).

If he is an FEA (Field Application Engineer) which I thought was his job having had watched that interview with headphones.com before, then his job is to interface with the end customer, not design headphones.

Here he describes his measurement process:

That is not any kind of "process" to brag about. Averaging a few times? That is the protocol you said was: "Oratory is also a trained, qualified professional with a methodically precise measurement procedure. " There is nothing precise about averaging. As I have explained, averaging actually removes precision, doesn't add to it.

Bottom line, please don't exaggerate his qualification, nor his measurement accuracy. His qualifications are fine as is and is in no need of exaggeration to score points.

I am not comfortable giving his real name or other identifiable details over the internet without his permission (this could also be classed as doxing, which is actually illegal in some countries). Everyone should have the right to online privacy.

Everyone does until they need to prove who they are and what their qualifications are. If you left the guy well enough alone and not try to crown him as God of headphone testing, then all would be well. Otherwise, we would need to know who he is to put any faith behind your accolades.

I personally also don't appreciate members of the industry staying under an alias. It is totally unprofessional. People have a right to know who they are and what biases/commercial interest they may have. Indeed, it is a Federal Law in US (FTC) to clearly stipulate such relationships.

So no, it is not "doxing." It is you backing up your exaggerations about his qualifications and testing. If you can't, then please stop it.

 

[pwjazz]

Then I was correct that his setup is not the same as Harman's. Nor is it any better than what I am using. You put his setup on a pedestal as if the situation is different.


If he is an FEA (Field Application Engineer) which I thought was his job having had watched that interview with headphones.com before, then his job is to interface with the end customer, not design headphones.


That is not any kind of "process" to brag about. Averaging a few times? That is the protocol you said was: "Oratory is also a trained, qualified professional with a methodically precise measurement procedure. " There is nothing precise about averaging. As I have explained, averaging actually removes precision, doesn't add to it.

Bottom line, please don't exaggerate his qualification, nor his measurement accuracy. His qualifications are fine as is and is in no need of exaggeration to score points.


Everyone does until they need to prove who they are and what their qualifications are. If you left the guy well enough alone and not try to crown him as God of headphone testing, then all would be well. Otherwise, we would need to know who he is to put any faith behind your accolades.

I personally also don't appreciate members of the industry staying under an alias. It is totally unprofessional. People have a right to know who they are and what biases/commercial interest they may have. Indeed, it is a Federal Law in US (FTC) to clearly stipulate such relationships.

So no, it is not "doxing." It is you backing up your exaggerations about his qualifications and testing. If you can't, then please stop it.

@amirm and @bobbooo what would you think about reaching out to him and inviting him to join the forum? Clearly there's a lot of synergy between his work and Amir's, and actual productive discussions to be had.

 

[amirm]

@amirm and @bobbooo what would you think about reaching out to him and inviting him to join the forum? Clearly there's a lot of synergy between his work and Amir's, and actual productive discussions to be had.

I have never invited anyone to the forum. It sets the expectation that they will be afforded special privileges. It is really best if they see value in what we are doing and join. Otherwise they will come and then leave shortly thereafter.