Epos speakers

[daftcombo]

Hi,

I would like to know if anyone had experience with the british brand Epos.

I've read most of their speakers had the "UK sound" like B&W, boosted low-mid and dip in the 4kHz-6kHz range.

I have a pair of K3. They sound clean but the RF is not flat on-axis. Off-axis it is, +/- 2.5 dB.

Cheers

 

[digicidal]

Can't find much info on them, but based on measurements of other offerings by them I'd guess it's pretty much all over the place FR wise. They look attractive though IMO. I've definitely seen better options, even in really cheap budget models - at least if the ES 14 and M 12.2 are any indication.

 

[daftcombo]

Here's an off-axis 30° FR I found in Hi-Fi World (sept 2015) for the K3. As for on-axis, the reviewer says it "peaks a little" and advises to position them without toe-in.
The company doesn't publish any measurement.

 

[digicidal]

Yikes that resolution! That doesn't seem too bad at all... though I don't know what the red line is. I'm assuming that's in-room due to the things going on <160Hz but that 800Hz-1.4kHz section would definitely make for some weirdness I'd think - but nothing horrible at all. If that's 30° off, then I'd say that's probably where you'd want them. and you could tame that ~1.4kHz peak a little with REQ to make them a little more neutral with a fairly nice falloff of a couple dB's over the full FR. I'd definitely love to see something at about 10X that resolution to know for sure though.

 

[daftcombo]

I don't know what the red line is

It's the port (not at the same dB scale as the speaker).

 

[daftcombo]

If that's 30° off, then I'd say that's probably where you'd want them. and you could tame that ~1.4kHz peak a little with REQ to make them a little more neutral with a fairly nice falloff of a couple dB's over the full FR. I'd definitely love to see something at about 10X that resolution to know for sure though.

A -4dB at 1400 Hz Q=4 might be a bit violent don't you think?

 

[digicidal]

Honestly its really hard to say without better resolution... but it's also likely that the actual impact of that could be exaggerated in the chart and the actual frequencies impacted could be small. Maybe what looks like a 4dB peak from ~1200-1400Hz is really just a single peak at 1360Hz that's really narrow and isn't perceptible at all (or just barely so). Same could be true for the -4dB suckout that appears to run from 700-900Hz but maybe it's just two spots at 750Hz and 850Hz?

Although the speaker would definitely be the problem that high in the FR rather than the room... it's hard to say how noticeable it would be other than maybe making a bit of a nasal edge or a "forwardness" in some vocals. I presume that's where the crossover to the tweeter occurs? You can see a similar thing on my Polk RTiA1's at a much higher resolution here:

Chart 2 - Listening Window
Listening Window, 20Hz - 20kHz (measured @ 2m, plotted @ 1m)

Response curve is an average of five measurements:
on-axis, 15 degrees left and right off-axis,
15 degrees up and down off-axis​

However, in actual listening I find them to sound subjectively quite neutral as well when used a bit farther out (more like 20° -30°) which takes a bit more glare off the highs than this. In any case, even looking like that... when graphed for linearity... there's basically no issues at all in that region - so probably little improvement to be had with the EPOS as well, I would guess:

Chart 4 - Deviation from Linearity at 90dB and Above
Difference @ 90dB, 50Hz - 20kHz (measured @ 2m)

Curve: difference from 70dB at 90dB​

Hopefully someone far smarter and more qualified than I can step in and help with some EQ advice if needed. That's an area where I'm still researching mostly and have far too little expertise to even attempt a guess - especially with so many unknowns. Sorry.

 

[Erik]

The graph is from Stereoplay magazine.

 

[digicidal]

Ouch... now I see where the 30° recommendation comes from... as it takes out that midrange a bit. However, in comparison to their stated specifications:

Frequency Range: 41 Hz – 30 kHz Impedance: 4 Ohm nominal Sensitivity: 91dB / 2.83V@1m

The impedance is right and reasonable, but everything else is stretching things pretty far IMO. If that FR is considered the operating range then it looks like that's a +/- 5dB range at least. And 91dB is definitely a stretch as well (although to be fair I am only assuming the measurement was taken at 2.83V@1m as well) looks more like 88dB at most - which is still great.

Despite that, I think the only real issue would be that peak in the midrange... the rising highs past 7kHz shouldn't be overly dramatic since hearing is less sensitive there but the midrange would definitely sound forward and colored IMO. Maybe just try to take that 1500Hz area down 2-3dB to start?
They might actually sound too soft in the highs at 30° but I would definitely take that over the on-axis levels any day! They would probably be fantastic (even on-axis) for dialog-heavy movies and TV though - on music it would likely depend on what genre you listen to the most.

I wonder if bypassing the passive network and using an active crossover wouldn't allow for significant improvements. It seems like that tweeter is not very well behaved in general - but again, I'm definitely no expert in that area.

 

[daftcombo]

View attachment 35338

The graph is from Stereoplay magazine.

Wow, thanks very much! I had been searching for such measurements for a long time!
Those cortoborate with own with REW below 1 kHz.

 

[daftcombo]

They might actually sound too soft in the highs at 30° but I would definitely take that over the on-axis levels any day!

At the moment I listen almost on-axis because I have them 3 m apart (10 ft) because of furniture and had to toe them in in order to have a focused stereo image. Perhaps I should untoe them a bit before using RePhase.

Would you try to bump the dip at 800Hz?

 

[digicidal]

At the moment I listen almodt on-axis because I have them 3 m apart (10 ft) because of furniture and had to toe them in in order to have a focused stereo image. Perhaps I should untoe them a bit before using RePhase.

Would you try to bump the dip at 800Hz?

Possibly, although it would depend on how it sounds to you mostly. I'd probably put a bit of a boost around 800Hz and a bit at 5500Hz and see how you like that... not much though I'd try 2-3dB to start. That should make them more consistent with neighboring frequencies. In reality it's likely that they look worse on the graph than they sound.

 

[daftcombo]

Possibly, although it would depend on how it sounds to you mostly. I'd probably put a bit of a boost around 800Hz and a bit at 5500Hz and see how you like that... not much though I'd try 2-3dB to start. That should make them more consistent with neighboring frequencies. In reality it's likely that they look worse on the graph than they sound.

At 5500Hz at 30° the blue curve is above the green and red ones so it seems ok. Would you boost it based on an average of the three curves?

 

[daftcombo]

View attachment 35338

The graph is from Stereoplay magazine.

According to this graph, how much power do I need?

 

[daftcombo]

Working on a correction for the Epos K3.
First, I settled them to they aim straight at the wall behind my couch, no toe-in.
Second, I made and applied (in JRiver) this correction curve in order to compensate for peaks & dips measured in Stereoplay (thanks @Erik): https://www.audiosciencereview.com/forum/index.php?threads/epos-speakers.9282/post-242286

Here's the correction curve

The extra bass rejection is to compensate for the speakers being close to the back wall.

The sound seems more neutral to me. I'm not sure I won't need a bit of toe-in to have a more focused image though.
Still a bit bright perhaps...

 

[daftcombo]

View attachment 35338

The graph is from Stereoplay magazine.

Are there any distortion measurements in this magazine?

 

[Erik]

Are there any distortion measurements in this magazine?

 

[daftcombo]

View attachment 44941

Not bad, actually.

Where those curves obtained on-axis? by average? the frequency response differs from the ones you posted before.
This makes me skeptical about my corrections.

 

[daftcombo]

View attachment 35338

The graph is from Stereoplay magazine.

The graph gives good information about: should one consider buying this speaker or not?

But it doesn't really help for EQ-correction.

Broad peaks can be either representative of a real broad peak in the FR, or of a sharp peak looking less sharp because of smoothing of the curve. So one doesn't know which kind of correction appli: low or high Q, and with which gain, at a given frequency.

I will take my own measurements once again. The peak at 1420Hz is the most audible from what I can hear. I think it is sharper and higher than what we can see on this graph, but in a very sensible zone for the ear.