JBL L Series (1990s)

[localhost127]

yes, help would be helpful

a cheap omni mic such as: http://recordinghacks.com/microphones/Behringer/ECM8000
and free software sure as Room EQ Wizard: http://www.hometheatershack.com/roomeq/

you want to test for a few things:
1) frequency response (with no smoothing). response can change drastically even over the course of a few Hz. by measuring every 10Hz as above, you cannot see what is going on in between.

2) waterfall plot. this is based on the time-domain (decay times)...e.g. "modal ringing". so, even if you are able to "eq" your frequency response to be fairly "flat"...you can still have modal ringing which is essentially the time it takes for a signal to decay. for example, if you played a 50hz sine wave (for a brief moment) and measured how long it took for the sound to decay after the source stopped, it could be something as high as 500ms. that means once the source has stopped, it takes a 1/2second for that 50hz energy in the room to decay down. when you are playing music with fast bass notes, long decay times can make things sound muddy and all the notes run together.

3) ETC graph. this is to measure specular reflections/energy.

take a moment to read this if you have time:
http://www.realtraps.com/art_measuring.htm

[localhost127]

also, a quick/dirty explanation of SBIR.

bass is omni-directional. which means it doesnt matter which way your port or driver faces...bass is emitted in all directions (it wraps around the cabinet and functions as a wave -- and diffracts around objects smaller than the wavelength).

ok, so say you place your sub or L7 3ft from the front wall. what happens?
well, bass is emitted from the driver in all directions as a wave. so it goes directly to your ears in the listening position, but also reflects off the front + side walls, ceiling, etc...

when 2 waves combine (constructively) to be in phase with each other, there will be a peak and an increase in amplitude at that frequency. when 2 waves arrive out of phase (180*), then you will have a null and you will not hear that frequency.

ok, so say your L7 is 3ft from the front wall.
that means, if a particular frequency's 1/4wavelength is 3ft (total wavelength = 12ft), then that means you will create a null. this is because the wave will travel from the L7 to the front wall (1/4wave = 3ft), reflect off the front wall, and enter back into the room. it will travel another 1/4wave (3ft) when it reaches the L7. so what has just happened? you now have (at a particular frequency) the original wave from the driver itself being emitted, but also being COMBINED destructively with the wave that traveled to the front wall, reflected off of it, and is now re-entering the room.

but since it took 1/4wave to the front wall, and 1/4wave back...that = 1/2wave.
so you now have a wavelength that is reflected off the front wall that is COMBINING with the original wave being emitted by the driver and thus is 180* out of phase. this means you will not hear this frequency as you will be in a null.

as you move the L7 (or sub) towards the front wall, you are decreasing the distance between the driver and the front wall, and thus pushing the 1/4wavelength up in frequency. and of course, the higher the frequency, the easier it is to treat/tame with acoustic treatment.

-------------------

the same happens with the rear wall and the listening position.
if your head is 6ft from the rear wall, then whatever frequency (and multiple there-of) has a 1/4wavelength of 6ft, means you will not hear that frequency as you will be sitting in a null (this is over-simplified, but good enough for the scope of this conversation).

the sound wave travels from the L7, past your head, 1/4wavelength from your head to the rear wall + 1/4 wavelength from the rear wall back to your head ... combines with the original signal (1/4 + 1/4 = 1/2wavelength = 180* out of phase), and thus destructively combines to cancel out and create a null.

[grumpy]

I understand what you're saying, and in-room interpretation (even of unsmoothed,
seemingly controlled environment data) is difficult at best (e.g., a single measurement
location is really not sufficient, IMO). Using tools and techniques that you've added
is helpful (also, as a -start- toward understanding room/source interaction), so thanks
for that.

There are also those that would like to try to improve or optimize their listening
experience within what I'd call normal limitations (re both the user involvement
and the listening environment). Not everyone wants to commit to a laptop/mic/
preamp/... or to learning a very useful, and wonderfully provided, but complex tool such
as RoomEqWizard (with which one might go quite a bit further in their learning
journey, should they decide to do so).

I will claim that using purchasable or downloadable tones and test signals with one's
ears and hopefully a sound level meter of some sort, if possible, is both educational
and potentially useful in that some level of improvement is both possible and likely
given decent coaching and signal selection.
Or at least a slightly better understanding of some of the myriad trade offs, limitations,
and potential benefits of scooting placement around, changing speaker height,
moving listening location, taking care with specular reflections, etc...

[localhost127]

I understand what you're saying, and in-room interpretation (even of unsmoothed,
seemingly controlled environment data) is difficult at best (e.g., a single measurement
location is really not sufficient, IMO). Using tools and techniques that you've added
is helpful (also, as a -start- toward understanding room/source interaction), so thanks
for that.

There are also those that would like to try to improve or optimize their listening
experience within what I'd call normal limitations (re both the user involvement
and the listening environment). Not everyone wants to commit to a laptop/mic/
preamp/... or to learning a very useful, and wonderfully provided, but complex tool such
as RoomEqWizard (with which one might go quite a bit further in their learning
journey, should they decide to do so).

I will claim that using purchasable or downloadable tones and test signals with one's
ears and hopefully a sound level meter of some sort, if possible, is both educational
and potentially useful in that some level of improvement is both possible and likely
given decent coaching and signal selection.
Or at least a slightly better understanding of some of the myriad trade offs, limitations,
and potential benefits of scooting placement around, changing speaker height,
moving listening location, taking care with specular reflections, etc...

i don't trust my own ears, especially when it comes to specular reflections (and trying to destroy all early reflections above -20dB within 20ms of the original source; reflection-free-zone)...let alone anything regarding LF (especially decay times). my ears can't "hear" comb-filtering...no matter how detrimental it is to sound quality.

put it this way --- it's orders of magnitude cheaper to do some do-it-yourself room treatments than to buy better equipment/gear. and better gear will still be placed into a room with the same fundamental problems. not to mention, increasing the size of the sweet-spot at hte listening position when applying basic room treatments. it is incredibly inexpensive to build some do-it-yourself treatments...and the noticeable difference in quality is not communicative through words here...


for example: the purpose of a 'reflection free zone' is to destroy all early/first reflections that are above -20dB of the original signal, and that arrive within 20ms of the original signal. the brain cannot distinguish reflections that arrive within 20ms of the original source as a seperate 'echo', thus smearing takes place. not to mention, comb-filtering from a reflected source converging with the original source at your ears...creating a multitude of peaks and nulls.

also, regarding stereo imaging. in a normal room, you have the left speaker emitting sound that travels to your left ear. it will also reflect off the RIGHT wall and enter your right ear. this harms stereo imaging. by placing broadband absorption (or reflecting the sonic energy elsewhere in the room), and by creating a reflection free zone, you will dramatically increase sound quality.
here's a wonderful writeup:
http://www.ethanwiner.com/acoustics.html
http://www.realtraps.com/rfz.htm

[localhost127]

There are also those that would like to try to improve or optimize their listening
experience within what I'd call normal limitations (re both the user involvement
and the listening environment). Not everyone wants to commit to a laptop/mic/
preamp/... or to learning a very useful, and wonderfully provided, but complex tool such
as RoomEqWizard (with which one might go quite a bit further in their learning
journey, should they decide to do so).

ahh, but people would gladly spend up to and over thousands of dollars on better and better gear ... than to spend $50 on a mic and free software... spend a few hours reading documentation and understanding just what the issues are they're trying to solve, and getting their room sounding good so that ANY speaker will have maximized performance and sound quality.

it's the same as people on the internet debating and bragging about how "ruler-flat" their (expensive) speaker's response curve is (measured in an anachronic chamber, mind you) --- when all of that is completely thrown out the window as soon as the speaker is placed in a room.

[grumpy]

Not much argument there But I wouldn't want to
discourage anyone from learning more, regardless of
their fiscal situation... Same rules apply with minimal
systems.

[Titanium Dome]

I delayed posting a reply, localhost127, because, frankly, the general tone of your post pi$$ed me off. It's not that what you wrote was technically incorrect, but man you've got to lighten it up. Here's what I originally wrote, but delayed posting.

Well professor, you really have your lectura gravis groove going there, don't you?

I think it's great when an expert and/or genius comes along and uses the forum to bring up short other members who are making irresponsibly speculative and observational comments based on subjective experience and exploration. I really like it when science is invoked in the name of bitch-slapping. Who doesn't like a good dose of over-used acronyms and specious criticism with a cup of Joe? It's so much cooler than making friends. There's hair growing on my chest right now.

Plus you pulled the anechoic card! Loved it! No one's pulled that one out in a while, but damn it was good to see it again. It's so real world, too! "Get thee to the anechoic chamber, Satan! Make sure you use a calibrated mic in there, too, and set it at the correct distance. Don't post again until you have a graph and data set notarized by the NIS/NBS."

If you don't mind, I'll use the "ridiculous smoothing" bit on grumpy next time he's over and he reaches for that darn smoothing menu and dialog box thingy that pops up. Busted!

Ah, good times.

As you can tell, I was not at all happy with the way you tasked JBLAddict. You can be right about something and still be totally wrong in your presentation. You don't need to respond to my quote above, since it's only included to show how I took your post, and you weren't even writing to me. I can only imagine how JBLAddict took your post.

All of us, including grumpy, JBLAddict, and especially myself can learn a lot from the interaction here, but not when it is so heavy-handed, dismissive, and objectionable in tone. I swear that if you try to defend yourself or ask for proof about what was negative or offensive about your manner of posting then I will simply put you on my ignore list and be done with you. Lansing Heritage like most other sites has its own know-it-alls and attack dogs, and they get on the ignore list. Some people have me on their ignore list (or should have done it and just shut up).

Please find the time to read this:

http://nlu.nl.edu/academics/cas/ace/...ltLearning.cfm

[grumpy]

If you don't mind, I'll use the "ridiculous smoothing" bit on grumpy next time he's over and he reaches for that darn smoothing menu and dialog box thingy that pops up. Busted!

Feel free... as long as you want to sit through an explanation of why
sometimes it's useful to do so

Overall, there's some useful information here,
that may rub off on a few folks that were thinking
they were going to read about L-series JBLs and
got rickrolled. A general audio subforum thread
or pointers to places like the noted Ethan Winer pages
would be good OT detours for further such discussions
or studies.

[localhost127]

I delayed posting a reply, localhost127, because, frankly, the general tone of your post pi$$ed me off. It's not that what you wrote was technically incorrect, but man you've got to lighten it up. Here's what I originally wrote, but delayed posting.

Titanium Dome, my original response was merely:
"unfortunately, there really is no conclusion to draw from such data."

i then followed-up with a more detailed post explaining why.

Titanium Dome, i understand you contribute a lot to this forum. however, you yourself have the same attitude dismissing any type of scientific or "measurable" information regarding one's room being the issue. your commentary regarding the L7s seem to imply that the room makes no difference in the way the L7s sound, when in fact the room is the single largest factor in any acoustic response. some of the knowledge known today regarding small room acoustics weren't known or weren't well established at the time of the L7's release. you continually give specific details on how and where others should place their L7s, even down to a single degree of toe-in !! you have found optimal placement in your room, and therefore think that you have found the L7s sweet spot, when in fact your are just finding your room's sweet spot. when you communicate L7 placement to others, it is not necessarily transferable to other rooms. there are good "starting points" (e.g. such and such distance from the side/rear walls), but acoustics is far too complex and no two rooms are alike. it's fairly well understood that the room has the single, biggest effect on frequency response and overall quality of sound. low frequency response is largely determined by modal characteristics of the room (via geometric dimensions). i have been debating that every room is different, and thus no exact placement/setup for the L7s in one room will guarantee the same performance in another room ... as each room has their own issues (dimensions, material the walls are made out of, and an almost infinite number of other variables) --- and that each user needs to experiment in their room (hopefully, with measuring equipment) to find the optimal placement. that is the basis of all of my commentary. i disagree that the L7 has a magical sweet spot that will function the same in every room, as you seem to imply. there are far too many variables involved which i think are being dismissed in your commentary.

for example, you've stated:

As you know, I'm a big proponent of the L7 "under the right circumstances." The right placement can solve almost all L7 issues, even if it seems it would not in this case.

the right placement doesn't solve the L7's issues, as the issues generally lie within the room itself. as you are moving the L7's 12" driver from one point to another, you are changing the response at the listening position based on the geometric distances of the boundaries within the room. moving the L7 on any axis will change the frequency response, comb-filtering of mids/highs (early reflections off boundaries), and other factors.

Placement has solved both issues and will solve both issues if you have the freedom to really find the right spot in a more-or-less normal room. If not, then a pair of L5s and a sub would fare better for you.

placement alone cannot solve all issues within a room. you will have peaks and nulls based on the geometric distances between the boundaries (walls), and where the driver is located. you will also have issues that the room creates that happens once the signal has left the speaker (e..g comb-filtering, modal ringing, etc) of which the room dictates and not of the driver itself. when you move your L7s, you are changing the response in every location of the room. in a rectangular (and especially square) room, you will never have a perfectly flat response in a single location. which is why ive repeatedly stated a user should experiment with placement to find the best response in their room via measurements, and from there the remaining specific issues can be addressed with room treatments.

Hey, thanks Detroit for pointing out the obvious.

i suppose it's ok for you to make sarcastic comments but not others.

It can place reflection points before or after traditional, expected places,

reflection points are reflection points. the L7 does not modify this unless you physically move it...geometry is geometry (angle of incident = angle of reflection).

L7s are designed for "normal" rooms, whatever they may be. They weren't designed in the era of "every room should be treated." They were designed in the era of stereo reproduction that assumed there's a hard wall, there's a corner, there's another hard wall, there's an eight foot ceiling, there's a floor.

what on earth dictates a "normal room"? what does the time period in which they were designed in have anything to do with room treatments? how does one design a speaker for a treated room? a speaker should be as flat as possible, and then the room needs to be treated to be flat as well. a treated room is to cure fundamental problems that EVERY room has, due to the nature of acoustics. it is not specific to the L7 or any other speaker for that matter. if you have a speaker that is advertised as flat from 20-20khz (measured in an anechoic chamber), then the second that speaker is placed in a room, the response will change. unless you are outside with no boundaries and the ground is fully absorptive.

you cannot design a speaker for "normal rooms" ... moving the driver feet or in some cases inches will have a drastic effect on frequency response. this is due to the geometric dimensions of the boundaries, not the speaker itself.

I don't have a single room treatment in my office with the L7s: hard walls, right angle corners, hard ceiling, carpeted floor: amazing, glare-free, wonderful, full soundstage, deep soundstage, perfectly balanced sound. Three feet in, three feet over, 17 degree toe-in, perfection

again, all speculative. you yourself know what sounds good in one particular room and therefore you exert this same "solution" onto everyone else in this forum, even though you do not know anything about anyone else's rooms. and look how precise you are in your placement! 17*s ! do you have a polar lobe plot of the speakers horizontal and vertical dispersion? do you have measurements that can back up your claims? you are the one offering this solution to many others on this forum, therefore, it is only fair that one asks for proof that the solution provides performance as you claim!

L7s are picky; they don't work in every room. They don't work like other speakers in every room. You may just need to let them go. I doubt they can be "fixed."

L7s aren't necessarily picky - it's just the difficulties with full range speakers. where be the optimal placement for mids/high's (e.g. directional to the listening position), is not generally the best place for the low frequency drivers. could you detail further how you come to your conclusion that they dont work in every room? what type of room do they work in? all i am looking for is for clarification on your comments. that is all.

Yep. I have "better" speakers but none gave me the "Aha!" moment the L7s did when I finally took the time to do them right. "Oh, that's what they meant about placement."

As you can tell, I was not at all happy with the way you tasked JBLAddict. You can be right about something and still be totally wrong in your presentation. You don't need to respond to my quote above, since it's only included to show how I took your post, and you weren't even writing to me. I can only imagine how JBLAddict took your post.

JBLAddict can speak for himself, and i can address him directly if i have done him wrong.
I didn't task JBLAddict in any way shape or form -- hell, im not even sure what you mean with that statement. i spent a few moments and took time out of my schedule to explain a concept to another member of the forum --- thereby, contributing to the community. you seem to see it as anyone explaining a topic to someone who does not understand it or possible who has mis-understood it as showing off. maybe you read my posts now with a little too much emotion and view my words through an emotional lense.

All of us, including grumpy, JBLAddict, and especially myself can learn a lot from the interaction here, but not when it is so heavy-handed, dismissive, and objectionable in tone.

why didn't you include me in your sentence? i have as much to learn as anyone else. you seem to be drawing a line in the sand (aka "us vs you")..

I swear that if you try to defend yourself or ask for proof about what was negative or offensive about your manner of posting then I will simply put you on my ignore list and be done with you.

i dare you to find any such attitude or dismissive tone in any of my previous commentary.
hey, Titanium Dome, in response to the above quote you said, let me give you a taste of your own medicine. you should read and live by your own words:

"You can be right about something and still be totally wrong in your presentation."

Lansing Heritage like most other sites has its own know-it-alls and attack dogs, and they get on the ignore list. Some people have me on their ignore list (or should have done it and just shut up).

you called me out so it's only fair im able to respond.

my apologies if my response came off as arrogant or pissy. to be honest, this is not one of my core forums i visit and thus do not have a lot of time invested. so i don't take the same amount of time to write my responses as i would on other sites that i value. it's more of a 'drive-by' commenting. i do not sit here and spend 30minutes writing a specific response that is purposely meant to come across as asshole'ish --- if anything, writing too quickly and not reviewing before submitting is the cause of that.

but ive replied to you in depth before with a more scientific approach (even replying to you sentence by sentence), and you immediately shrugged it off, wrote it off, etc without so much as fielding a reputable debate or reply.

you offer insight and knowledge to a host of vintage products that is worth its weight in gold --- as information is so scarcely available. i am grateful for that and you answered plenty of my questions in an outstanding fashion. but i suggest if you disagree with some of my comments regarding the topic at hand, that you field the ball back into my court via a casual debate. present your side of the argument with scientific facts to back them up (vs subjective), and we can see how things play out and everyone can hopefully learn something new. take care.

[localhost127]

Feel free... as long as you want to sit through an explanation of why
sometimes it's useful to do so

there is nothing wrong with smoothing. in the context of my post, we are addressing low frequency response, where there can be huge swings in amplitude over the course of a single frequency. that is all that i was trying to convey.

Overall, there's some useful information here,
that may rub off on a few folks that were thinking
they were going to read about L-series JBLs and
got rickrolled. A general audio subforum thread
or pointers to places like the noted Ethan Winer pages
would be good OT detours for further such discussions
or studies.

i am not one that can afford a plethora of vintage JBL speakers. i found my L7s on craigslist for a steal. i cannot afford to continually upgrade my gear as others can.
however, by a bit of hard work and studying some acoustics docs, i have been able to create do-it-yourself room treatments at a very minimal cost that have made absolute wonders of noticeable difference in sound quality. as many others who have finally learned how simple room treatments can have drastic differences, i wish to communicate this knowledge to others. i know a few other people who can go out and spend thousands of dollars on upgraded amps, which only offer slight (if any) noticeable improvement ... and yet it costs only a few hundred bucks in insulation and fabric to make measurable differences in a room. it is by far the cheapest bang-for-your-buck in noticable improvement regarding freq response, decay times, and stereo imaging.

[grumpy]

Cool. Start a new thread indictating what you did with
before and after measurements.

[Titanium Dome]

you yourself have the same attitude dismissing any type of scientific or "measurable" information regarding one's room being the issue. your commentary regarding the L7s seem to imply that the room makes no difference in the way the L7s sound, when in fact the room is the single largest factor in any acoustic response. some of the knowledge known today regarding small room acoustics weren't known or weren't well established at the time of the L7's release. you continually give specific details on how and where others should place their L7s, even down to a single degree of toe-in !! you have found optimal placement in your room, and therefore think that you have found the L7s sweet spot, when in fact your are just finding your room's sweet spot. when you communicate L7 placement to others, it is not necessarily transferable to other rooms. there are good "starting points" (e.g. such and such distance from the side/rear walls), but acoustics is far too complex and no two rooms are alike. it's fairly well understood that the room has the single, biggest effect on frequency response and overall quality of sound. low frequency response is largely determined by modal characteristics of the room (via geometric dimensions). i have been debating that every room is different, and thus no exact placement/setup for the L7s in one room will guarantee the same performance in another room ... as each room has their own issues (dimensions, material the walls are made out of, and an almost infinite number of other variables) --- and that each user needs to experiment in their room (hopefully, with measuring equipment) to find the optimal placement. that is the basis of all of my commentary. i disagree that the L7 has a magical sweet spot that will function the same in every room, as you seem to imply. there are far too many variables involved which i think are being dismissed in your commentary.

for example, you've stated:



the right placement doesn't solve the L7's issues, as the issues generally lie within the room itself. as you are moving the L7's 12" driver from one point to another, you are changing the response at the listening position based on the geometric distances of the boundaries within the room. moving the L7 on any axis will change the frequency response, comb-filtering of mids/highs (early reflections off boundaries), and other factors.



placement alone cannot solve all issues within a room. you will have peaks and nulls based on the geometric distances between the boundaries (walls), and where the driver is located. you will also have issues that the room creates that happens once the signal has left the speaker (e..g comb-filtering, modal ringing, etc) of which the room dictates and not of the driver itself. when you move your L7s, you are changing the response in every location of the room. in a rectangular (and especially square) room, you will never have a perfectly flat response in a single location. which is why ive repeatedly stated a user should experiment with placement to find the best response in their room via measurements, and from there the remaining specific issues can be addressed with room treatments.



i suppose it's ok for you to make sarcastic comments but not others.



reflection points are reflection points. the L7 does not modify this unless you physically move it...geometry is geometry (angle of incident = angle of reflection).



what on earth dictates a "normal room"? what does the time period in which they were designed in have anything to do with room treatments? how does one design a speaker for a treated room? a speaker should be as flat as possible, and then the room needs to be treated to be flat as well. a treated room is to cure fundamental problems that EVERY room has, due to the nature of acoustics. it is not specific to the L7 or any other speaker for that matter. if you have a speaker that is advertised as flat from 20-20khz (measured in an anechoic chamber), then the second that speaker is placed in a room, the response will change. unless you are outside with no boundaries and the ground is fully absorptive.

you cannot design a speaker for "normal rooms" ... moving the driver feet or in some cases inches will have a drastic effect on frequency response. this is due to the geometric dimensions of the boundaries, not the speaker itself.




again, all speculative. you yourself know what sounds good in one particular room and therefore you exert this same "solution" onto everyone else in this forum, even though you do not know anything about anyone else's rooms. and look how precise you are in your placement! 17*s ! do you have a polar lobe plot of the speakers horizontal and vertical dispersion? do you have measurements that can back up your claims? you are the one offering this solution to many others on this forum, therefore, it is only fair that one asks for proof that the solution provides performance as you claim!



L7s aren't necessarily picky - it's just the difficulties with full range speakers. where be the optimal placement for mids/high's (e.g. directional to the listening position), is not generally the best place for the low frequency drivers. could you detail further how you come to your conclusion that they dont work in every room? what type of room do they work in? all i am looking for is for clarification on your comments. that is all.







JBLAddict can speak for himself, and i can address him directly if i have done him wrong.
I didn't task JBLAddict in any way shape or form -- hell, im not even sure what you mean with that statement. i spent a few moments and took time out of my schedule to explain a concept to another member of the forum --- thereby, contributing to the community. you seem to see it as anyone explaining a topic to someone who does not understand it or possible who has mis-understood it as showing off. maybe you read my posts now with a little too much emotion and view my words through an emotional lense.



why didn't you include me in your sentence? i have as much to learn as anyone else. you seem to be drawing a line in the sand (aka "us vs you")..



i dare you to find any such attitude or dismissive tone in any of my previous commentary.
hey, Titanium Dome, in response to the above quote you said, let me give you a taste of your own medicine. you should read and live by your own words:

"You can be right about something and still be totally wrong in your presentation."




you called me out so it's only fair im able to respond.

my apologies if my response came off as arrogant or pissy. to be honest, this is not one of my core forums i visit and thus do not have a lot of time invested. so i don't take the same amount of time to write my responses as i would on other sites that i value. it's more of a 'drive-by' commenting. i do not sit here and spend 30minutes writing a specific response that is purposely meant to come across as asshole'ish --- if anything, writing too quickly and not reviewing before submitting is the cause of that.

but ive replied to you in depth before with a more scientific approach (even replying to you sentence by sentence), and you immediately shrugged it off, wrote it off, etc without so much as fielding a reputable debate or reply.

you offer insight and knowledge to a host of vintage products that is worth its weight in gold --- as information is so scarcely available. i am grateful for that and you answered plenty of my questions in an outstanding fashion. but i suggest if you disagree with some of my comments regarding the topic at hand, that you field the ball back into my court via a casual debate. present your side of the argument with scientific facts to back them up (vs subjective), and we can see how things play out and everyone can hopefully learn something new. take care.

Perhap you missed this recent post:

There is no such thing as a "perfect room for L7s" but every room can be better or worse depending on how much one cares about the outcome. Since JBL cannot know what room the L7 will be placed it, it gave some best practices for starting the fit the L7 into your room. I ignored that advice for years, and as a result thought that the L7 was a good but not great speaker. It had anomalies like shrill peaks and muddy valleys. Once I listened to what the manual was saying, they had the potential to go from good to great.

Now I always start using the manual as the reference point and make adjustments from there. So a question like "Why do you have the toe-in at 25 degrees when JBL writes 15?" gets an answer like this: "Because I started at 15 degrees, and when I went shallower it sounded worse, when I went deeper it sounded better up to a point and then it got worse again, so I went to the point where it sounded best. It's what works in this room."

It's specific to one room. There's no sense in which this is other than a general guide to a placement process. A process is an ongoing series of activities to reach an intended or hoped-for conclusion. The conclusion in this case is one that the end user finds most satisfactory.

For the typical user in the early '90s, this was it. Neither JBL nor the typical installer talked about SPL meters, EQ, PEQ, room treatments, etc. Audio chain and placement were king and queen respectively. Sure there was science involved in the creation of the products, but limited scientific application at the end user interface. It was preference in the given environment.

You are correct that room treatments would help, but who is thinking about room treatments in a typical home environment, shared with other family members for a pair of $400 speakers (in today's market)? Sure, there are many effective, low impact means: carpets, wall hangings, book cases, drapes, but all of these require participatory decisions that sometimes are difficult to broach in a domestic environment.

In any event, while I am aware of the huge pile of evidence and opinion about the importance of room treatment, its place of importance is certainly open to discussion. You say it is first, and you have good reasons for that assertion. I say it is third, and I have good reasons for that assertion as well. It is very important, but it is not first or second in importance in my experience. In fact it's really 3-B, not 3-A on my list of what's important.

If you want to get into a deeper discussion of this, I'll follow grumpy's advice to you and start a thread. Perhaps this will tempt you.

Here's my list.

1. Speaker
2. Speaker placement
3-A: Room
3-B: Room treatments
4-A: Pre/DAC
4-B: Amp
5. Dedicated power circuit
6. Everything else

http://www.audioheritage.org/vbullet...oom-Treatments

In the case of the L7, #2 is even more prominent than with more traditional full range speakers.

(There finally back on thread.)

[Titanium Dome]

my apologies if my response came off as arrogant or pissy. to be honest, this is not one of my core forums i visit and thus do not have a lot of time invested. so i don't take the same amount of time to write my responses as i would on other sites that i value. it's more of a 'drive-by' commenting.

take care.

I will accept your apology as written and extend my own so we can move on.

Fair enough?

[localhost127]

cheers, m8.

this thread needs more pics

[JBLAddict]

Thanks gentlemen for the spirited discussion and helpful links.

I have actually "gone through" most of the links when initially searching for the absorption panels that now line my walls. I can claim to understand a good chunk of it, but at this point am not willing to go down the road of integrating pretty complicated software/PC to my system and attempt to not only make sense of it, but make appropriate changes. From my time on the forums, clearly there are a few who go quite deep in this area, and knowing what they know may understandably get a "little" frustrated when the less informed make bold statements and equipment changes that totally miss what can be fixed with data and appropriate treatment.

I'm pretty happy with my L7s, but was attempting to do a poor man's version of response measurement realizing the room is foremost and I've far from optimized the combination--> clearly this was done incorrectly and out of helpful context.

For now, I guess I'll just use my ears best possible, and if motivated, hire someone to run the tests and recommend the right treatments. As an engineer, data driven action is appealing, but I know my limits in this case.