JBL 305P MkII Review (Erin)

[hardisj]

The 225 Hz resonance is interesting -- hard to see anything there in the spin other than a small dip (the one at 1.7ishK is obvious). But you can see in MZKM's normalized horizontal plot that there is some clustering going on at that frequency -- just hard to imagine such a small thing would have such an audible effect!

This stuff always stands out to me. I blame it on my car audio upbringing where getting good midbass is the single hardest thing I think anyone can do. Harder than climbing Mt. Everest, even.

But seriously, trying to learn how to tune midbass in a car has made me more aware of midbass issues. Kind of like how someone who has experience with a particular instrument may always be more sensitive to issues with the reproduction of that in the recording or the speakers.

It has been my experience that even mild FR disturbances in the LF region are very audible. ((Maybe it is because the notes played here are often so succinct. A guitar is likely to hit an exact note; a human will span a few octaves when singing. So when the bass guitar hits around one of these resonances you hear the speaker light up.)) I have had similar experiences with other speakers that show impedance blips that indicate a standing wave. The Klipsch Heresy IV had a resonance around 110Hz, IIRC, and it was unbearable with male vocals.

 

[dfuller]

This is pretty close to my experience with these... And yes, the distortion is still super rough. well over 1% at 86dB anechoic at 1m throughout the midrange... yuck.

Also I believe much of that midrange tubbiness you're hearing is the front baffle itself. It's very thin and poorly braced plastic.

 

[thewas]

At first glance, it looks noticeably better than Amir's 305p measurements, and more inline with the 306 and 308 measurements. Also seems like it will be even better with the -2 treble tilt engaged. Haven't read yet.

Also that was my impression from my first glance but the spinorama of both which @MZKM posted above look more similar than I thought, with biggest difference Erins one having more resolution and a tad less treble:

 

[Sancus]

As expected, the predicted in-room response and the farfield response (3.5 meter, blue) line up quite well above approximately 500Hz. However, when moving to the nearfield (1.5 meter, red), the high frequency response is accentuated even more above 8kHz, reaching as much as +4dB compared to the farfield response/estimation.

I'm a bit confused by this line. Which 1.5m red measurement is this paragraph referring to? There isn't one in the graph above it.

Great review though, love the compression tests and hope to see them continue! I think it's interesting that this speaker shows so little compression, and I wonder if that's going to turn out to be common or not, and just how bad the bad examples will be. That Presonus looks quite a lot worse, BUT it is also tiny.

 

[hardisj]

I'm a bit confused by this line. Which 1.5m red measurement is this paragraph referring to? There isn't one in the graph above it.

Whoops!

That’s a leftover from another review which was used as a template. I’ll update the text.

 

[Bullwinkle J Moose]

This stuff always stands out to me. I blame it on my car audio upbringing where getting good midbass is the single hardest thing I think anyone can do. Harder than climbing Mt. Everest, even.

Getting great midbass in a car is easy

If it's not, then you're doing it wrong

Just eliminate the crosstalk and comb filtering effects, and then PooF, they are suddenly crystal clear and dynamic (Just like my home speakers)

 

[restorer-john]

Well, it is about levels.

Absolutely about reproduced levels. But the cause is thermal effects from heating etc and that will vary massively between say a tiny little 4" two way and a 5 way tower with three 8" woofers each with 2.5" voice coils.

In real terms, it is the small 2 ways that will exhibit the biggest changes in FR and general compression from thermal (VC) heating. But with a low powered amplifier such as these JBLs have, there really shouldn't be a problem.

The low efficiency passive bokshelves will be interesting in this regard.

Keep up your good work with the compression testing. In my experience, it is the single most frustrating aspect of compact loudspeakers when used at elevated listening levels for a reasonable time. It is the major reason I cannot take most bookshelf speakers seriously, especially for large orchestral (classical) pieces. Sure, for short 3-4 minute "audiophile" tracks or "girl and guitar" crap, they are fine.

 

[MZKM]

I find it odd that the 306P & 308P had a pretty flat treble.

306P:

308P:

Going in order of 305P->306P->308P:

​

I’d go 306P and fix the 1.5kHz dip and reduce 4kHz a tad.
The 306P has the best DI curves around 2kHz in terms of linearity.

Here is the Kali LP6 for those wanting to compare:

Unless the Kali can get louder, I‘d still probably take the 306P.

 

[napilopez]

((Maybe it is because the notes played here are often so succinct. A guitar is likely to hit an exact note; a human will span a few octaves when singing. So when the bass guitar hits around one of these resonances you hear the speaker light up.))

This makes a lot of sense! Plus so many fundamentals in that range. 225Hz is an A3.

 

[Vini darko]

Great job with the live stream Erin. You're a natural at it.

 

[dfuller]

As referenced on the livestream:
Scroll down to "modifications".
http://noaudiophile.com/JBL_LSR308/

 

[tktran303]

Thanks Erin,

Love your reviews. And the listening impressions are so instructive, to me, because as you know, all the squiggly lines only mean so much...

I’d always wondered what a budget of $300 buys in a commercial active speaker, vs the $3,000K/pair active.

And yes it IS quite a lot. I previously thought I should buy one just as a litmus test. Now I won’t have to/don’t want to.

Have you got Mesanovic’s RTM10 in your testing schedule? If not, perhaps I will enquire...

 

[hardisj]

Love your reviews. And the listening impressions are so instructive, to me, because as you know, all the squiggly lines only mean so much...

Glad you find them helpful. I believe the data is very useful but the entire purpose of having test data is to correlate it to listening impressions. Otherwise, the data is just data. For a perfect speaker (not that there is one), all you need is data. But with a real speaker in the real world, it is necessary to try to see where/if you can pair the data to something that you hear.

Have you got Mesanovic’s RTM10 in your testing schedule? If not, perhaps I will enquire...

I did ask/offer sometime last year. I was told they had others who were going to do a review and I didn't ask again.

 

[More Dynamics Please]

As referenced on the livestream:
Scroll down to "modifications".
http://noaudiophile.com/JBL_LSR308/

The key to the noaudiophile review is near the bottom where he makes the following observations after giving up on running the 308s full range and making a "last ditch attempt" by crossing over to his subs at 80 Hz:

With the low frequencies taken over by the subwoofers, the JBL's sound sublime.

The clarity and impact of the midbass is excellent using even a rudimentary crossover to a subwoofer.

 

[hardisj]

Great job with the live stream Erin. You're a natural at it.

I appreciate you joining. I definitely liked doing that more than filming myself and then editing it for a day. I’d much rather have a “conversation” and I feel like the live stream is more like that. If the feedback is mostly positive then I may just do more live reviews.

 

[dfuller]

The key to the noaudiophile review is near the bottom where he makes the following observations after giving up on running the 308s full range and making a "last ditch attempt" by crossing over to his subs at 80 Hz:

With the low frequencies taken over by the subwoofers, the JBL's sound sublime.

The clarity and impact of the midbass is excellent using even a rudimentary crossover to a subwoofer.

Sounds to me like the issue is too much is being asked of these drivers. A quoted F3 of 49hz (on the 305s) is pretty low for a small box with a 5.25" driver. I'd expect without DSP these would be rolling off about 10hz above that.

 

[Biblob]

How's the static noise levels, compared to the Kali IN-5's?

 

[dominikz]

This makes a lot of sense! Plus so many fundamentals in that range. 225Hz is an A3.

What I noticed with my LSR305 (gen 1) is that the backplate resonates around ~250Hz, and much more strongly on one speaker than the other. After some investigation I found the routing in MDF was too small, so the bacplate was quite tightly jammed which worsened the resonance. E.g. it was very difficult to remove the backplate on that unit because of this, while on the other unit the backplate would basically fall off if unscrewed.

 

[daftcombo]

Not that I noticed when sitting as close as a couple feet away.

Were you using the cables coming with the speakers to feed them with electricity? I suspect them to be shit and increase hiss.

 

[daftcombo]

The 225 Hz resonance is interesting -- hard to see anything there in the spin other than a small dip (the one at 1.7ishK is obvious). But you can see in MZKM's normalized horizontal plot that there is some clustering going on at that frequency -- just hard to imagine such a small thing would have such an audible effect!

It good be the fundamental in the dip + the harmonics also lower normal?