Can the /excessiveness/ of the 8361A be better utilised?

[8361AM]

This is a pretty well explored subject. It is safe to do so within the xmax of the driver at any frequency response in a sealed speaker, and above the port tuning frequency on a ported speaker. There is no inherent difference between just turning up the volume and applying EQ, you are just shifting the tonal balance of the speaker.



Which arguments / what type of arguments would it take to convince you? The reason it is a bad idea is that below the tuning frequency there is no inherent damping from the cabinet, so your driver will be "flapping in the wind" so to speak. This will quickly lead to your 8361 no longer having a bass driver, which is not ideal.




I think the main reason you're not getting a lot of traction from a science perspective is that the science behind your question is already well known and understood.



A) It already has almost flat response all the way down to the port tuning frequency. The port tuning is around 40hz, so below that you will not get any more meaningful output by EQing it. Above that you can EQ it. It will limit maximum SPL but otherwise be fine.
B) Not for me to say.


View attachment 411622

Thank you for taking the time to reply so helpfully.

In terms of an argument to convince me, it'd be helpful to understand where I'm going so wrong. Perhaps the following example can help us to identify the issue:

(a) Our ported speaker goes flat down to 36Hz
(b) The speaker begins to roll from 36Hz and then rapidly from 30Hz (reaching -6dB at 30Hz)
(c) Our goal is to configure the speaker to extend flat to 30Hz because we listen to music extending this low
(d) If we set a -6dB 40Hz shelving filter using GLM, the response is most usefully boosted from 30-36Hz (the area we most want to target; see attached)
(e) This filter is similar to the +2dB 100Hz shelving filter from around 60-400/500Hz but increasingly boosts below 60Hz, resulting in the speaker extending to 30Hz at 0dB rather than -6dB (see attached)
(f) However, the 36-60Hz range is then boosted above our initial flat response, so we address it using EQ
(g) The <30Hz range is boosted even more but this seems less problematic because of the steep roll off that appears less sensitive to the filter's tilting effect and our music not extending lower than 30Hz (otherwise, perhaps EQ could be applied if our content did extend lower and the tilt was problematic)
(h) Thereafter, the SPL of the speaker is then limited so the <36Hz range places no greater stress on the speaker than the speaker being used some 10dB louder with no EQ (or perhaps more to be safe)

I fail to see the problem because I understand that all we've done is to change the <36Hz range relative to the >36Hz range. How is this so problematically different to the speaker being played some 10dB louder with no EQ applied?

When you state that there "...is no inherent difference between just turning up the volume and applying EQ...", this seems to support what I've proposed. However, your comments thereafter suggests that I may be attempting something else. Unsure where I'm going so wrong or if there's been a miscommunication. Please do put me out of my misery...

 

[sigbergaudio]

Thank you for taking the time to reply so helpfully.

In terms of an argument to convince me, it'd be helpful to understand where I'm going so wrong. Perhaps the following example can help us to identify the issue:

(a) Our ported speaker goes flat down to 36Hz
(b) The speaker begins to roll from 36Hz and then rapidly from 30Hz (reaching -6dB at 30Hz)
(c) Our goal is to configure the speaker to extend flat to 30Hz because we listen to music extending this low
(d) If we set a -6dB 40Hz shelving filter using GLM, the response is most usefully boosted from 30-36Hz (the area we most want to target; see attached)
(e) This filter is similar to the +2dB 100Hz shelving filter from around 60-400/500Hz but increasingly boosts below 60Hz, resulting in the speaker extending to 30Hz at 0dB rather than -6dB (see attached)
(f) However, the 36-60Hz range is then boosted above our initial flat response, so we address it using EQ
(g) The <30Hz range is boosted even more but this seems less problematic because of the steep roll off that appears less sensitive to the filter's tilting effect and our music not extending lower than 30Hz (otherwise, perhaps EQ could be applied if our content did extend lower and the tilt was problematic)
(h) Thereafter, the SPL of the speaker is then limited so the <36Hz range places no greater stress on the speaker than the speaker being used some 10dB louder with no EQ (or perhaps more to be safe)

I fail to see the problem because I understand that all we've done is to change the <36Hz range relative to the >36Hz range. How is this so problematically different to the speaker being played some 10dB louder with no EQ applied?

Below the port frequency, both the natural roll-off due to the port/cabinet tuning + the active DSP high pass employed by Genelec will fight your applied EQ, so it will not be very effective, and the risk of damaging the driver is much higher.

As others have said, the best for you to do is likely to experiment yourself. As long as you don't get bad noises from the speaker, you are probably good.

When you state that there "...is no inherent difference between just turning up the volume and applying EQ...", this seems to support what I've proposed. However, your comments thereafter suggests that I may be attempting something else. Unsure where I'm going so wrong or if there's been a miscommunication. Please do put me out of my misery...

You are cherry picking my sentences. Immediately before that, I wrote "This is a pretty well explored subject. It is safe to do so within the xmax of the driver at any frequency response in a sealed speaker, and above the port tuning frequency on a ported speaker. "

 

[Digby]

@8361AM If you want to explore the science behind this, rather than attempt it on your own loudspeaker, there are plenty of books and papers that explain why your line of thinking, as far as extending the frequency range lower, is a bad idea with a ported speaker. Someone linked one such paper a few pages back.

It is fine to explore ideas and be a beginner in this, as you are. I am much closer to beginner than any expert, of which there are several who frequent the forums, some have posted in this thread.

There are people of all knowledge levels here, and everyone is welcome, but when several people are pointing you away from doing this or suggesting reading material to explain why it doesn't work well in theory or practice, perhaps it is worth heeding their advice?

If any of us seem rude it is because we are giving up time to explain something that would be explained by some brief reading. If you get the fundamentals in order (by reading, as suggested), then it will be easier to converse with people on this topic and everyone can feel like they are 'getting somewhere' with the discussion.

 

[Purité Audio]

I suppose someone has already suggested, ‘buy subwoofer’?
Keith

 

[Randyman...]

Wow - this thread is still going

 

[8361AM]

Many thanks for all your feedback thus far.

I'd be grateful to focus on the question rather than my personal situation for the time being because of its potential relevance to others who may not have the same room dimensions or tastes (but more than happy to address them later).

Three observations motivated this post:

(a) the 8361A has an excess of SPL for many users
(b) SPL can be traded for LFE
(c) Some users are happy to trade SPL for LFE

If anyone strongly disagrees with the above, please explain why.

Assuming there is agreement, I sense it'd be useful to contrast the 8260A and 8361A:

(a) the 8260A has a frequency response of 29Hz-20 kHz (± 1 dB) whereas the 8361A has a frequency response of 36Hz-20 kHz (± 1.5 dB)
(b) the 8260A has a 150W bass amplifier and short term max SPL of ≥113 dB whereas the 8361A has a 700W bass amplifier and short term max SPL of ≥118 dB.

In summary, the 8260A extends lower than the 8361A but at the cost of SPL.

Whilst I can't speak for all 8361A owners, I'd be surprised if many of us would turn down an opportunity for our speakers to perform a little more like the 8260A in terms of LFE assuming that distortion does not enter the equation and SPL is sufficient. This seems superior to simply adding a shelving filter because a flat frequency response is maintained but with greater LFE (e.g., 29Hz rather than 36Hz at ± 1.5 dB). What I'm less sure about it how. How can we determine what filters to apply and how should this be implemented (e.g., via a custom GLM speaker profile or perhaps another application such as EqualizerAPO)?

PS. 8260A and 8361A frequency response graphs attached.

Many thanks for the replies since my last post.

I understand now. The issue was with observation (b); as above. I understand from the information that's been shared that ported speakers are extremely inflexible in terms of LFE extension. If you want to trade SPL for greater LFE to a worthwhile and safe degree, and without excessive complication, you need a sealed speaker.

It's been an interesting but perhaps frustrating experience at times, but I'm sure I've been the overall greater cause of frustration and for this I apologise. I will again state how grateful I am to those who have responded and perhaps most of all to those who kept at it and finally helped me to understand (thank you for your patience and persistence).

Thank you, ASR!

 

[8361AM]

You are cherry picking my sentences. Immediately before that, I wrote "This is a pretty well explored subject. It is safe to do so within the xmax of the driver at any frequency response in a sealed speaker, and above the port tuning frequency on a ported speaker. "

I see this now but it wasn't intentional at the time; more a case of not understanding as there seems to be an awful lot of technical knowledge required to really understand what you've shared (e.g., knowing it's a well explored subject as well as having a good understanding of the terms you mention). I'm clearly not at that level... I guess there was a mismatch between what was expected of me and what I thought was expected of me, and that as someone fortunate enough to have access to this kind of expertise, the onus is on me to be better.

One thought that occurred to me since posting earlier, was that the problem with my proposal was that the speaker can happily extend to 30hz at -6dB and 36Hz at 0dB but not 30Hz and 36Hz at 0dB. I don't mean to provoke given my above comments, but perhaps you may be willing to respond with a yes or a no as to whether this matches with what you've been sharing with me. If so, I think I get it now.

 

[sigbergaudio]

I see this now but it wasn't intentional at the time; more a case of not understanding as there seems to be an awful lot of technical knowledge required to really understand what you've shared (e.g., knowing it's a well explored subject as well as having a good understanding of the terms you mention). I'm clearly not at that level... I guess there was a mismatch between what was expected of me and what I thought was expected of me, and that as someone fortunate enough to have access to this kind of expertise, the onus is on me to be better.

One thought that occurred to me since posting earlier, was that the problem with my proposal was that the speaker can happily extend to 30hz at -6dB and 36Hz at 0dB but not 30Hz and 36Hz at 0dB. I don't mean to provoke given my above comments, but perhaps you may be willing to respond with a yes or a no as to whether this matches with what you've been sharing with me. If so, I think I get it now.

In theory it could be possible with some very narrow notch filters, but since the tuning frequency of the port is at 40hz, it would be a bit of a struggle to get 30hz lifted by 6dB without creating an uneven response here.

If we have a look at the measurement by Amir, we see that the speaker itself (the output from the actual bass driver), is -6dB as high as ~43hz. And the port has a pretty narrow band. Relative to the peak we're at -6dB at something like 28hz and 65hz.

And if we look at the measurements from Genelec, we see they already have a number of different bass roll-off variants built-in, with significant differences in output at 30hz. We don't which one of this is closest to the natural response of the speaker. But there's likely already some EQ lift in the ones with the most bass. Not that the excursion (how far the driver has to move) increases exponentially as the frequency goes down, and as we approach 20hz you can barely hear it. Even 30hz is not that easy to hear. So you risk having EQed quite a bit without hearing much difference, while in reality you are about to push the driver over the edge of what it is capable of, to little audible effect.

 

[gnarly]

I understand now. The issue was with observation (b); as above. I understand from the information that's been shared that ported speakers are extremely inflexible in terms of LFE extension. If you want to trade SPL for greater LFE to a worthwhile and safe degree, and without excessive complication, you need a sealed speaker.

Good to see the understanding gained

I'd say the issue with your original premise to trade SPL for greater LFE is that in the case of the 8361 it is simply not worthwhile.
Safety is not really an issue, assuming Genelec has put in decent limiters, which I feel is a very safe assumption trusting Genelec.

The yellow highlight to the 8361's processed response curve indicates the maximum SPL that can reached by low frequency, and then have level response above that low frequency corner throughout the rest of the spectrum.

So for example, if you are willing to constrain SPL to 75 dB, you could potentially with the right EQ's, have f-3 response down to about 27Hz.

However, the yellow corner below, the knee as it's called, will need to be made significantly sharper.....with a much tighter radius.
It will take a carefully crafted set of PEQ's, perhaps along with some negative shelving to construct. It will also greatly shoot up group delay, not a good thing.

I think you can safely toy with this if you desire, but again frankly, it's not worth it other than a learning exercise.
(Just get a sub for lower extension, and you can still listen to both the 8361 and sub at lower volume...like everyone has said.)

If you are still into experimenting/learning, try a PEQ at around 28Hz. It will need to be higher Q, say 5 or greater, and maybe about +5dB gain.
Shelving will NOT work. Only sharpening the corner is where extension can be gained. (and again, not a good idea for sound quality)
Keep overall SPL to 75dB at 1m, and play with the PEQ. If the limiter is worth half a shit, you won't hurt anything.

My perspective is that of a bass-reflex sub designer, including processing & limiting, for both thermal and excursion.
I've designed limiters for bass-reflex that are both frequency and level dependent, although I seldom bother with anything other than regular RMS and Vpeak limiters.
It is possible to run bass reflex with no limiting at in place, and then have it progressively kick in with increasing levels and lower content.

 

[gnarly]

In theory it could be possible with some very narrow notch filters, but since the tuning frequency of the port is at 40hz, it would be a bit of a struggle to get 30hz lifted by 6dB without creating an uneven response here.

Yes, exactly. That's what I hoped I showed in previous post.

 

[8361AM]

Thank you @sigbergaudio and @gnarly for repeatedly being so generous with your time.

Given my already hugely positive experience of the 8361A, I'm grateful to own something so resistant to tweaking. Despite my desire to tweak, which almost always brings benefit, I'm instead forced to enjoy. This is a rare thing. Thank you Genelec for producing such a wonderful speaker and to all those who have helped me to realise this...

 

[Tovarich007]

One of the strangest threads I've ever read and taken part in ASR... 6 pages of technological explanations, suggestions, warnings, exchanges... just to get back at the start and the evidence : these speakers are excellent just as they are, within their limits (all speakers have some).

Anyway enjoy your 8261s, they're pretty good and they actually go low, maybe just a few herz less low than you ideally want.
Just keep in mind we're not living in an ideal world and everything will be fine.

 

[8361AM]

One of the strangest threads I've ever read and taken part in ASR... 6 pages of technological explanations, suggestions, warnings, exchanges... just to get back at the start and the evidence : these speakers are excellent just as they are, within their limits (all speakers have some).

Anyway enjoy your 8261s, they're pretty good and they actually go low, maybe just a few herz less low than you ideally want.
Just keep in mind we're not living in an ideal world and everything will be fine.

I think there's also been some interesting psychology going on but perhaps best to leave things be and so not encourage a 12+ page thread!

EDIT: In support of @Tovarich007, this quote springs to mind: "We shall not cease from exploration, and the end of all our exploring will be to arrive where we started and know the place for the first time." This suggests to me that I'm in the right place. Thank you for contributing this.

 

[Tovarich007]

A sort of " Nietztschean" thread : "The Eternal Return" applied to audio.

Enjoy your speakers and ASR

 

[8361AM]

A sort of " Nietztschean" thread : "The Eternal Return" applied to audio.

Enjoy your speakers and ASR

"Thou art a God, and never did I hear anything so divine!"

 

[RobL]

Thank you for taking the time to reply so helpfully.

In terms of an argument to convince me, it'd be helpful to understand where I'm going so wrong. Perhaps the following example can help us to identify the issue:

(a) Our ported speaker goes flat down to 36Hz
(b) The speaker begins to roll from 36Hz and then rapidly from 30Hz (reaching -6dB at 30Hz)
(c) Our goal is to configure the speaker to extend flat to 30Hz because we listen to music extending this low
(d) If we set a -6dB 40Hz shelving filter using GLM, the response is most usefully boosted from 30-36Hz (the area we most want to target; see attached)
(e) This filter is similar to the +2dB 100Hz shelving filter from around 60-400/500Hz but increasingly boosts below 60Hz, resulting in the speaker extending to 30Hz at 0dB rather than -6dB (see attached)
(f) However, the 36-60Hz range is then boosted above our initial flat response, so we address it using EQ
(g) The <30Hz range is boosted even more but this seems less problematic because of the steep roll off that appears less sensitive to the filter's tilting effect and our music not extending lower than 30Hz (otherwise, perhaps EQ could be applied if our content did extend lower and the tilt was problematic)
(h) Thereafter, the SPL of the speaker is then limited so the <36Hz range places no greater stress on the speaker than the speaker being used some 10dB louder with no EQ (or perhaps more to be safe)

I fail to see the problem because I understand that all we've done is to change the <36Hz range relative to the >36Hz range. How is this so problematically different to the speaker being played some 10dB louder with no EQ applied?

When you state that there "...is no inherent difference between just turning up the volume and applying EQ...", this seems to support what I've proposed. However, your comments thereafter suggests that I may be attempting something else. Unsure where I'm going so wrong or if there's been a miscommunication. Please do put me out of my misery...

^^emphasis mine^^
My 8361A’s already extend flat down to 26hz via room gain.

 

[holdingpants01]

^^emphasis mine^^
My 8361A’s already extend flat down to 26hz via room gain.View attachment 411738View attachment 411739

exactly this was my suggestion on the page 1, yet he preferred to get the same response about how the BR works for 6 pages straight while at the same time suggesting no one understand his point, until he finally got it The answers were on the first page this whole time

 

[MAB]

exactly this was my suggestion on the page 1, yet he preferred to get the same response about how the BR works for 6 pages straight while at the same time suggesting no one understand his point, until he finally got it The answers were on the first page this whole time

This exactly.

 

[AudioJester]

exactly this was my suggestion on the page 1, yet he preferred to get the same response about how the BR works for 6 pages straight while at the same time suggesting no one understand his point, until he finally got it The answers were on the first page this whole time

Lol!
The mods should sticky this thread - as an example of what not to do on ASR!

Nothing wrong with any sort of question, I ask stupid ones all the time, but if we cant learn from the answers.....

 

[Kyle_PL]

^^emphasis mine^^
My 8361A’s already extend flat down to 26hz via room gain.

For better quality, and smaller size of screenshots from programs, try ALT+PrintScreen buttons, and in Paint use CTRL+V, then save to *.png file.

ps. GLM is awesome