JBL LSR305P MKii and Control 1 Pro Monitors Review

[sweetchaos]

I see some people are confusing the JBL's.

There are 2 generations:
1. LSR 305
Previous generation
Sold from Aug 2013 to Jan 2019 on amazon.com
The LSR305 are officially discontinued by JBL.
2. 305p MKii
Current generation
Selling from Jan 2018 on amazon.com

If anyone is talking about the previous generation (LSR305), please indicate so, as this review is for current generation (305P Mkii).

 

[Blake Klondike]

Oh, I misunderstood your post in my previous response. I thought you were asking for re-test of EQ settings in JBL 305P.

Answering correctly now, absolutely! This the very reason for these tests. They clearly show frequency response variations which you are calling EQ.

Thanks so much! Really excited about the speaker reviews.

 

[briskly]

I also find these plots very easy to read!

This might be a stupid question, but: All of these speakers have much more energy storage (or whatever we call it) in the bass region. What's the simple reason for that? Do sealed speakers exhibit similar waterfalls in the bass region, or is it a function of the port/bass reflex?

One way to see the problem is that the additional frequencies force the temporal decay of the speaker. The vented woofer has a sharper cutoff and will exhibit a longer temporal decay. Q-factor is the parameter of energy storage from cycle to cycle, but it has the double meaning of how narrowly focused a resonance is relative to the center frequency.

General relation of time and frequency is that behaviors in one term tend to do the opposite in the other. Quick temporal decay implies broader frequency slopes. High-resolution in frequency limits what is clear temporally.

 

[LTig]

Same, I find them very readable. It's normalized, though, right? I mean, it looks like group delay isn't shown, since all the frequencies start at 0 ms.

No idea.

 

[RayDunzl]

I have a pair of 305P here.

Here are old measurements of one speaker in-room at 10 feet, with and without external EQ with 1/12th octave smoothing

Flat to 30hz here with a little help...

Not too bad without.

 

[laudio]

I have a pair of 305P here.

Here are old measurements of one speaker in-room at 10 feet, with and without external EQ with 1/12th octave smoothing

View attachment 45488

Flat to 30hz here with a little help...

Not too bad without.

Was the little help a subwoofer? Can't believe that speaker can be flat to 40 Hz let alone 30.

 

[StevenEleven]

Was at Guitar Center today just to play with all the toys, and they had hooked up and live in their DAW sales room. . . the 305P mk2s! They had about thirty boxes of them off in the corner for $300 a pair.

Observations:

They were much smaller than I thought! They had the larger 308s hooked up too, which were about the size I imagined the 305s would be.

Although it was hard to extrapolate in the ambient noise at a Guitar Center, it seemed like the hiss could at most be slightly problematic out to 4 or maybe perhaps 5 feet in a normal living room, and not at all past that. This is a wild-assed guess (WAG).

The hiss of the 305s and 308s seemed about the same. Another WAG.

There was no hiss in the first two detentes of the volume knob of the 305s, and then the hiss kicked in at a steady state from the third detente on.

I was sooooooo tempted too pick up a pair of 305s. They are just sitting there, boxes and boxes and boxes of them!!! I’ll probably break down and get a pair before too long. . .

 

[Wombat]

If one suffers from tinnitus it is easier to be forgiving about very low level hiss in cheaper gear.

 

[SplitTime]

Hi Amir,
Great review and I’m in the midst of trying to figure out what I want to get as my next system - so this is very relevant to me. I went and watched the YouTube of Toole as referenced from your other (recent) intro post. I’d sort of settled on getting a Benchmark DAC3, HPA4, AHB2 for stereo setup - the question then was what speakers... At a local store I was able to demo the KEF LS50W and B&W 805 D3s. I took in my own iPod, playing DSDs through an Oppo HA2 SE - to the line-in of the KEF and the amplifier they had in the store driving the B&Ws. I thought the B&W 805s were significantly better sounding than the KEF LS50Ws - playing Jazz: Nora Jones, Dave Brubeck, ... Rock: Boston, ... Classical: Anne-Sophie Mutter Carmen-Fantasia and others. Then, after watching Toole’s YouTube I went and did some more research (reading online) on the JBL M2, 708p/i (7 series), 305P mk ii... and I read about the background hiss on some of the JBL xxxP speakers. This sounds like the built-in amplifiers have a high noise floor...

So my concern/question here is - we look at a spinorama of frequency and speaker response but it seems there is no data at all about noise floor (and only, with added cost/tooling/testing can we get any actual measurements on speaker distortion). It seems like the speakers are the generally the weak link in the system (please correct me if that’s not the case). While I’m tempted to go get a pair of JBL 708Ps (7 series) or M2s based on spinorama - they basically force you (if I understand correctly) to use their JBL’s amplifiers (built in or external) ... which means those could be dumping a huge amount of noise and/or distortion into the system that makes a Benchmark (or similarly quality DAC & pre-amplifier) irrelavent. Am I missing something here?? Or, even with these sorts of Speaker measurements are we still missing something by measuring individual components that might still give us an unclear picture of the entire audio reproduction chain from source file to listener’s ears?

Again, I’m really very grateful for your (and other contributors) work here. It has been very educational and helpful. I’ve bought a few items so I could hear for myself what the measurements imply. So, I really do not intend this to be a complaint in anyway - just wondering if I am really missing something or if there is indeed still a measurement gap?

Thanks again!

Edit: Would it be possible to drive the JBL 708i (if they have a passive version) (or JBL M2) with the Benchmark AHB2 (or one per M2) instead of using the JBL’s required amplifier? Toole mentioned in the YouTube clip that he believed integrated amplifier-speaker combinations were the future. This suggests to me that perhaps they’re getting such a good spinorama by electronic adjustments they’re doing in the amplifier stage. So this is part of my concern - if that is indeed what is being done, then how do we measure the net effect of both speaker and amplifier?

 

[pkane]

Was at Guitar Center today just to play with all the toys, and they had hooked up and live in their DAW sales room. . . the 305 mk2s! They had about thirty boxes of them off in the corner for $300 a pair.

Observations:

They were much smaller than I thought! They had the larger 308s hooked up too, which were about the size I imagined the 305s would be.

Although it was hard to extrapolate in the ambient noise at a Guitar Center, it seemed like the hiss could at most be problematic out to 4 or 5 feet in a normal living room, and not at all past that. This is a wild-assed guess (WAG).

The hiss of the 305s and 308s seemed about the same. Another WAG.

There was no hiss in the first two detentes of the volume knob of the 305s, and then the hiss kicked in at a steady state from the third detente on.

I was sooooooo tempted too pick up a pair of 305s. They are just sitting there, boxes and boxes and boxes of them!!! I’ll probably break down and get a pair before too long. . .

The hiss in my 306p2’s is just like that: barely audible at a few feet and not audible at all further away. It may be an issue if these are used as desktop speakers. I use them as surrounds for a 5.1 system. Hiss is not remotely a problem in this application.

 

[RayDunzl]

Was the little help a subwoofer? Can't believe that speaker can be flat to 40 Hz let alone 30.

The Cheezewoofers claim to 23Hz.

Not used in this measurement.

Flat measure doesn't mean big meaty bass, just that the air wiggled at the microphone at that frequency and moderate level.

Even so, they sound full enough on their own, given what they are.

Louderness brings on distortion, though.

 

[amirm]

While I’m tempted to go get a pair of JBL 708Ps (7 series) or M2s based on spinorama - they basically force you (if I understand correctly) to use their JBL’s amplifiers (built in or external) ... which means those could be dumping a huge amount of noise and/or distortion into the system that makes a Benchmark (or similarly quality DAC & pre-amplifier) irrelavent. Am I missing something here??

The crossover settings for M2 are public (not sure how accurate though) and people have used their own amps and DSP to drive them. So you are not bound to use Crown or Mark Levinson amps.

 

[Neddy]

Hi Amir,
While I’m tempted to go get a pair of JBL 708Ps (7 series) or M2s based on spinorama - they basically force you (if I understand correctly) to use their JBL’s amplifiers (built in or external) ... which means those could be dumping a huge amount of noise and/or distortion into the system that makes a Benchmark (or similarly quality DAC & pre-amplifier) irrelavent.

Consider JBL 4367s, and pick your own amp(s)?
I happen to REALLY like those woofers....

 

[briskly]

@SplitTime
The 705i and 708i use passive filtering if you are hopelessly paranoid about the noise floor and have a low-noise amplifier. No other Harman products needed, contrary to what the sheet might suggest. M2 has had its crossover deduced, but this requires a little more effort on your part, configuring the digital crossover.
There is little point in chasing so many zeroes of THD when the signal has to go through a nonlinear medium. Air propagation is a major distortion source for compression drivers and certain horn assemblies, although subjective reports do not bear this out as sounding terrible.

 

[amirm]

Edit: Would it be possible to drive the JBL 708i (if they have a passive version) (or JBL M2) with the Benchmark AHB2 (or one per M2) instead of using the JBL’s required amplifier? Toole mentioned in the YouTube clip that he believed integrated amplifier-speaker combinations were the future. This suggests to me that perhaps they’re getting such a good spinorama by electronic adjustments they’re doing in the amplifier stage. So this is part of my concern - if that is indeed what is being done, then how do we measure the net effect of both speaker and amplifier?

I asked and was told that the M2 does have DSP functions to smooth its response. What those are, I don't know. So yes, there is some risk in using your own amp and DSP. Note that you must have electronic crossover and DSP for M2. So you need more amplification channels to go with that.

 

[Neddy]

The crossover settings for M2 are public (not sure how accurate though) and people have used their own amps and DSP to drive them. So you are not bound to use Crown or Mark Levinson amps.

@amirm What are the chances of you getting 4367s to test on your new rig?

 

[amirm]

@amirm What are the chances of you getting 4367s to test on your new rig?

Some day I am sure we will get one. Right now, it is not planned since even dealer cost is thousands of dollars.

 

[Xyrium]

I have a pair of 305P here.

Here are old measurements of one speaker in-room at 10 feet, with and without external EQ with 1/12th octave smoothing

Flat to 30hz here with a little help...

Not too bad without.

That's a nice room! Treated?

 

[Wombat]

@SplitTime
The 705i and 708i use passive filtering if you are hopelessly paranoid about the noise floor and have a low-noise amplifier. No other Harman products needed, contrary to what the sheet might suggest. M2 has had its crossover deduced, but this requires a little more effort on your part, configuring the digital crossover.
There is little point in chasing so many zeroes of THD when the signal has to go through a nonlinear medium. Air propagation is a major distortion source for compression drivers and certain horn assemblies, although subjective reports do not bear this out as sounding terrible.

References please on the air propagation/ CD/horn distortion relationship. Horn loudspeakers are of interest to me.

 

[maxxevv]

What is the difference between them?

The woofer is 6" instead of 5".

The comparative summary from JBL themselves.

Mostly in the size, amplification power and frequency range of the range. (there's a mistake in the specs of the driver size for the 305P)

https://jblpro.com/en-US/products/c...[]=308p-mkii&commit=Compare+Selected+Products