JBL SCL-7 Review (In-wall Speaker)

[nathan]

To be fair, it has only been a few weeks since the review was posted. But I too hope to hear some official response eventually.

 

[amirm]

@amirm , did you get answer from JBL about this distortion ?

Sorry, I forgot to ask. I even forgot I made such a promise.

 

[Cedrep]

Hi, JBL synthesis are top level line of JBL, they should have an explanation about huge 2nd harmonic distortion and dip in the 2k region.

Theses speakers are made to be use with EQ, what is the most important factor to be easely EQ able ?

 

[Cedrep]

Just seeing that HDI 1600 have exactly same distortion

JBL HDI-1600 Speaker Review

This is a review and detailed measurements of the JBL HDI-1600 two-way bookshelf speaker. They were purchased new and drop shipped to me for testing. The HDI-1600 costs US $900 for one. Note: my company Madrona Digital is a dealer for Harman products such as JBL line (although we hardly sell...

www.audiosciencereview.com

 

[nathan]

Theses speakers are made to be use with EQ, what is the most important factor to be easely EQ able ?

In short, consistent off axis response tends to make a speaker eq friendly since the eq will change the curve not just for the direct sound but also in a similar fashion for the reflected sound.

 

[nathan]

they should have an explanation about huge 2nd harmonic distortion and dip in the 2k region.

Sure would be nice to have an official response.

 

[C. Cook]

Curious as to why there was no notation of resonance on the Revel in-walls you tested. Seems like they are even worse. I know that you don't place as much stock in these graphs as some others and that your company actually sells both brands (both Harman products obviously), but generally you always call out resonances in the graphs.

 

[amirm]

Curious as to why there was no notation of resonance on the Revel in-walls you tested. Seems like they are even worse. I know that you don't place as much stock in these graphs as some others and that your company actually sells both brands (both Harman products obviously), but generally you always call out resonances in the graphs.

I did note it:

Response is nice and even until we get to crossover region around 2 kHz. Response droops there and becomes variable, likely due to resonances from the woofers:

But keep in mind that speaker is mounted to MDF which itself is stood up by its edge. So some resonances can be attributable to the fixture. And at any rate, once you mount this on your wall, you will experience your own version of it.

 

[C. Cook]

I did note it:


But keep in mind that speaker is mounted to MDF which itself is stood up by its edge. So some resonances can be attributable to the fixture. And at any rate, once you mount this on your wall, you will experience your own version of it.

Ah, yeah I was just talking about in the graph, but yes you did. On the other note you raised, I did see that it looked like you tested both with the same type of sheetrock or particle board suspended over a bit (looks like a foot actually) of furr-out in your wall. I don't have experience with in-walls so I assume they both have some sort of 'cabinetry' behind the woofers? If not, how do they control for the variations likely encountered w/r/t wall volume at different homes? Edit: You did say it's a different version for everyone, but I'm wondering if they design for a range of volume depending on the distance between opposing sheets of sheetrock, wall height, etc.

 

[amirm]

I don't have experience with in-walls so I assume they both have some sort of 'cabinetry' behind the woofers?

No. Some come with "back boxes" but many like this one do not. If they come with one, I will test it that way but so far none have.

 

[Valentin R]

Looking at options JBL did a great job
These are 3 times the cost

 

[Germanium]

Concerning that dip around 2KHz some manufacturers do that intentionally to create a sense of depth more than you would get in the recording played flat. I personally am not a fan of this.

I know from personal conversations with Bob Carver that that is how he designs his speakers.

I personally find that flat is good if you have an amp & source that is transparent any depth that is in actual recording will come through in spades. That is how my current setup is, very tranparent with oodles of depth even though it is not in any way soft at 2 KHz. As such it can both project sound forward or towards the rear totally dependant on quality of recording.

Many classical recordings have a preponderance of energy here yet have really great sense of depth.

 

[sarumbear]

I know from personal conversations with Bob Carver that that is how he designs his speakers.

The guy is a menace to Hi-Fi

At every opportunity he is crashing his legacy to pieces...

 

[jgs5607]

Compression drivers are notorious for producing large amounts of 2nd order distortion, especially if you push them a bit too low (what this looks like). Luckily you need copious amounts of it to be audible and even then it's unlikely to sound bad.

It isn't perfect but I'm guessing that no one will hear it.

I suspect you are right. My JBL Studio 590's and 580's use their 2414h-1 driver which has 98db sensitivity; by their own specs, the recommended minimum crossover frequency is 1.9KHz for that driver. In both towers, the crossover is at 1.5KHz and the crossover has a serial notch filter to dampen the resonance ( a band aid that would not be needed if used within recommendations). Reviews have shown a resonance near the crossover, so the band aid is not totally effective.

I can't say how much it affects the sound, but in my mind, I would prefer to use drivers that can work within limits.

I built a center channel to go with these towers since JBL does not have a capable Center for this series and used a B&C DE250 that has 10db higher sensitvity, a larger diaphram and has a minimum crossover of 1.5 KHz. Being padded down 15db to match the midbass and all of the other factors above, it is pretty much cruising at any level that the 590's can play. It ended up being a higher resolution speaker than the 5's.

Of course, I was not working to a price target; at the usual 4X markup, this would be a $1500.00 speaker.

JBL has more capable compression drivers, but the resulting speaker would be more than the current overpriced ( in my mind ) models they have.

 

[sumitagarwal]

I know these didn't exactly review very positively, but I'm still considering them for my L and R behind a woven acoustically transparent screen, along with the well-reviewed SCL-6 as my center.

Any thoughts on these for this specific application? I'm not good at interpreting the data myself.

 

[nathan]

I know these didn't exactly review very positively, but I'm still considering them for my L and R behind a woven acoustically transparent screen, along with the well-reviewed SCL-6 as my center.

Any thoughts on these for this specific application? I'm not good at interpreting the data myself.

They will work well in such a situation. And while the msrp feels a little high, as with most jbl and revel speakers, dealers will usually knock up to 30% off when buying a set, at which point their pricing get competitive in my opinion.

Be sure to fill the stud bay with insulation. Part of the challenge with these measurments is that the speaker is designed to be in a closed stud bay but the measurments are done without a closed stud bay. I’m not saying that would correct all of the issues in the measurments, but it would be a best practice and best bet.

Due to the unique angle of dispersion, these are a nice choice if you cannot place your left and right speaker in an angled wall (Baffle).

If you are able to build an angled wall, also consider KEF in wall speakers.

 

[rvsixer]

Just mho, on paper and sitting at less than around 40 deg off axis, I'd easily pick a trio of SLC-6's for LCR. Exact timbre match, even dispersion throughout (and less chance of lighting up the opposite wall), better FR flatness, better DI, better sensitivity, etc.

 

[nathan]

Just mho, on paper and sitting at less than around 40 deg off axis, I'd easily pick a trio of SLC-6's for LCR. Exact timbre match, even dispersion throughout (and less chance of lighting up the opposite wall), better FR flatness, better DI, better sensitivity, etc.

I don't disagree. In fact, if all ones seats are within the primary dispersion window of the the SCL-6 (either because the furthest left seat is not too far off axis from the front right speaker, for example, or because one is using an angled baffle wall behind the screen) then I strongly agree that three of these up front, vertically positioned with the tweeter at ear height, are going to be VERY NICE.

With both models, in a multiple row theater, I would be a little worried, since the vertical dispersion is so narrow. And I am still not a fan of manufacturers not supplying a backer box, and just assuming the stud bay dimensions will be acceptable.

 

[sumitagarwal]

I don't disagree. In fact, if all ones seats are within the primary dispersion window of the the SCL-6 (either because the furthest left seat is not too far off axis from the front right speaker, for example, or because one is using an angled baffle wall behind the screen) then I strongly agree that three of these up front, vertically positioned with the tweeter at ear height, are going to be VERY NICE.

With both models, in a multiple row theater, I would be a little worried, since the vertical dispersion is so narrow. And I am still not a fan of manufacturers not supplying a backer box, and just assuming the stud bay dimensions will be acceptable.

Thank you folks for the helpful insights!

Listening/viewing angle
My room seems to naturally drop the front/main row around "SMTPE closest" distance on a 150" screen, so about 47 degrees, and to maximize space plus since it's typically my wife and I and we like to stay close I'm going with a narrow 3-seat low-back reclining sofa. Figure speakers right within the edges of the screen will create a 45 degree spread. From the left and right seat I figure that puts the listeners at maybe 40 degrees from the opposite speaker?

Room reflections
My intent had been to control the near wall reflections as my assumptions was that these were the earliest and therefor most important to reduce. I hadn't considered as much the issue of lighting up the opposite wall. Are my assumptions incorrect here?

Non toed-in speakers/additional options?
In my particular situation the screen wall is an existing wall shared with a basement pantry and tool closet. Because of this I have a lot of leeway on the types and depths of speakers I can use. I wanted to retain the existing flat wall as a baffle wall, but It's not critical that I stick with shallow 4" deep in-wall speakers. It also isn't critical that I enclose the backs of the speakers. The primary attraction of some in-wall speakers, like the SCL-7 and the Monitor Audio IDC models, is the built-in ability to have an offset while keeping flush mounting on a flat wall.

I had been under the impression that infinite baffle setups are preferable if they are practical for a situation, and in my situation I can leave the backs of the speakers completely unenclosed instead of in a stud bay. I thought this would have benefits in less internal reflections within the speaker, less resonance (ports/etc), and less back pressure so the drivers can move more quickly and freely. Is my thinking wrong?

Alternatively since I don't need a shallow depth, I could consider full depth conventional speakers (say 12" or less) mounted into the wall, so long as they are sealed or front-ported.

Vertical dispersion/second row
I'm planning to optimize sound for the main row as the second row will be truly "secondary". As long as they can understand the dialogue and enjoy some subwoofer drama, I'm sure everyone back there will be very very happy. My plan is to have the tweeters vertically centered behind the screen, and first row eye level around 1/3rd of the way up the screen.

 

[nathan]

From the left and right seat I figure that puts the listeners at maybe 40 degrees from the opposite speaker?

Based on that math, I would get three of the SCL-6 models then.

Room reflections
My intent had been to control the near wall reflections as my assumptions was that these were the earliest and therefor most important to reduce. I hadn't considered as much the issue of lighting up the opposite wall. Are my assumptions incorrect here?

That is usually the safest route. It is possible with a wide dispersion (where there is consistent dispersion) like with these speakers that you don’t need as much absorption on the side walls as you might think. But I would start with your approach, AND some covering the lateral reflection (left speaker bounces off right wall toward listening position) points as well.

Then, based on listening and measuring, you may or may not change things up.