AV123 / GR Research X-Voce Speaker Review

[Milanraf]

Audiophile damping towel

 

[DSJR]

Well well

“A towel, [The Hitchhiker's Guide to the Galaxy] says, is about the most massively useful thing an interstellar hitchhiker can have. Partly it has great practical value. You can wrap it around you for warmth as you bound across the cold moons of Jaglan Beta; you can lie on it on the brilliant marble-sanded beaches of Santraginus V, inhaling the heady sea vapors; you can sleep under it beneath the stars which shine so redly on the desert world of Kakrafoon; use it to sail a miniraft down the slow heavy River Moth; wet it for use in hand-to-hand-combat; wrap it round your head to ward off noxious fumes or avoid the gaze of the Ravenous Bugblatter Beast of Traal (such a mind-boggingly stupid animal, it assumes that if you can't see it, it can't see you); you can wave your towel in emergencies as a distress signal, and of course dry yourself off with it if it still seems to be clean enough.”​

Life, don't talk to me about life...




Douglas Adams was a client of ours before the big money rolled in and he went all ARC/Krell and Sonus Faber
I'll get me towel - er - coat...

 

[dr.diesel]

Should do a review video of these turds also.

 

[Rick Sykora]

I think I know what the recommended NoRez is for on this one!

 

[anphex]

The directivity graph looks like a mindflayer, so ... win?

 

[JSmith]

Douglas Adams was a client of ours

Did you happen to meet him? One of my favorite authors of all time, it would have been excellent to have been able to do so.


JSmith

 

[Soniclife]

Life, don't talk to me about life...




Douglas Adams was a client of ours before the big money rolled in and he went all ARC/Krell and Sonus Faber
I'll get me towel - er - coat...

I'd guess he was Linn and Naim before, if his budget allowed.

 

[JayGilb]

I'd guess he was Linn and Naim before, if his budget allowed.

Was Linn reasonably priced a few decades ago ? Their latest offerings are very expensive.

 

[hmt]

Here is my take on the EQ

Please report your findings, positive or negative!
The following EQs are “anechoic” EQs to get the speaker right before room integration. If you able to implement these EQs you must add EQ at LF for room integration, that is usually not optional… see hints there: https://www.audiosciencereview.com/...helf-speaker-review.11144/page-26#post-800725

The raw data with corrected ER and PIR:

Score no EQ: 1.0
With Sub: 3.6


View attachment 326472
Spinorama with no EQ:

• pff..

Directivity:
pff again.:

View attachment 326480

View attachment 326488
EQ design:
I have generated two EQs. The APO config files are attached.

• The first one, labelled, LW is targeted at making the LW flat
• The second, labelled Score, starts with the first one and adds the score as an optimization variable.
• The EQs are designed in the context of regular stereo use i.e. domestic environment, no warranty is provided for a near field use in a studio environment although the LW might be better suited for this purpose.
• These EQ might not be suited for this king of speakers...

Score EQ LW: 4.3
with sub: 6.9

Score EQ Score: 5.3
with sub: 7.8

AV123 GR Research X-Voce APO EQ LW 96000Hz
November162023-105757

Preamp: -6 dB

Filter 1: ON PK Fc 86.19,    -8.86,    3.87
Filter 2: ON PK Fc 176.73,    6.78,    1.16
Filter 3: ON PK Fc 276.15,    -3.00,    3.30
Filter 4: ON PK Fc 418.27,    2.65,    4.67
Filter 5: ON PK Fc 480.54,    -2.91,    1.13
Filter 6: ON PK Fc 928.06,    5.72,    1.78
Filter 7: ON PK Fc 958.75,    -5.58,    4.06
Filter 8: ON PK Fc 2009.91,    -1.95,    4.08
Filter 9: ON PK Fc 4207.36,    -1.40,    4.31
Filter 10: ON PK Fc 7382.39,    -1.09,    1.90
Filter 11: ON PK Fc 12608.44,    -1.98,    3.96

AV123 GR Research X-Voce APO EQ Score 96000Hz
November162023-105757

Preamp: -5.9 dB

Filter 1: ON PK Fc 86.13,    -8.90,    3.61
Filter 2: ON PK Fc 172.17,    6.93,    1.17
Filter 3: ON PK Fc 278.81,    -3.43,    3.37
Filter 4: ON PK Fc 417.72,    2.79,    3.71
Filter 5: ON PK Fc 433.21,    -4.07,    1.32
Filter 6: ON PK Fc 906.63,    4.04,    2.55
Filter 7: ON PK Fc 939.69,    -3.79,    4.54
Filter 8: ON PK Fc 2273.70,    -3.37,    1.89
Filter 9: ON PK Fc 4089.57,    -1.99,    2.49
Filter 10: ON PK Fc 7934.53,    -2.81,    0.79
Filter 11: ON PK Fc 12973.59,    -2.29,    3.48

View attachment 326479
Spinorama EQ LW
View attachment 326473

Spinorama EQ Score
View attachment 326474

Zoom PIR-LW-ON
View attachment 326478

Regression - Tonal
View attachment 326476

Radar no EQ vs EQ score
Nice improvements?
View attachment 326475


The rest of the plots is attached.

The fact that this speaker does get an EQ 7.8 rating w/o subs is showing again that the model is only applicable to non EQed speakers.

 

[Toni Mas]

Very weird 2 peaks impedance curve for a closed box woofer. I rather looks like a BR impedance curve. Also the peaky bass response is what you get with cheapo crappy woofers with too high Qts to be used in BR. Definitely i cant believe It is really a closed box, and there must be a Reflex port somewhere , and this should be removed and closed.

 

[Soniclife]

Was Linn reasonably priced a few decades ago ? Their latest offerings are very expensive.

They were never budget, but they were much more affordable than now, but they always had options to spend more, just like Naim.

 

[abdo123]

The fact that this speaker does get an EQ 7.8 rating w/o subs is showing again that the model is only applicable to non EQed speakers.

Huh?

Crap speaker can’t get a decent score no matter what you do so the model is bad?

How did you even reach that conclusion?

 

[ctrl]

Very weird 2 peaks impedance curve for a closed box woofer. I rather looks like a BR impedance curve. Also the peaky bass response is what you get with cheapo crappy woofers with too high Qts to be used in BR. Definitely i cant believe It is really a closed box, and there must be a Reflex port somewhere , and this should be removed and closed.

I like the idea of the secret, hidden BR port But not every impedance double hump is caused by a BR concept (at least the cabinet plan does not provide for a BR port).

The impedance peak at 65Hz is the resonant frequency of the CB woofer. The impedance peak at 190Hz is most likely caused by the crossover between CB woofer and OB woofer.

With the CB woofer low-pass, the impedance near the crossover frequency increases with increasing frequency. With the OB woofer high-pass, the impedance increases with decreasing frequency near the crossover frequency.
Both together can then lead to an impedance peak (to simplify matters, the impedance phase frequency responses has been omitted).

 

[DanielT]

Amir, nice detective work with this test. Thanks for taking the time to do that. It was exciting.

____
If you were to plug the open baffle part of the speaker and make it completely a closed speaker, would that change the ski slope? Together with maybe fixing the passive crossover then, if necessary that is. Maybe fix a digital crossover and measure up and then..... but wait now. It is then more or less approaching a full DIY project. Then you might as well build something else, if you feel like building something.

Amir was well on his way with all the fixing he did with them. But going from that to completely rebuilding it might not be the trouble?

 

[DSJR]

I'd guess he was Linn and Naim before, if his budget allowed.

I think I may have once tweaked his Linn LP12, but as I was normally in the other store, I can't remember as by the mid 80's, he'd turned to the even darker side of the makers I mentioned and was pictured with that setup including huge white hosepipe speaker cables the UK distributor of ARC and Krell used to sell. My colleague at the main store did phone me up with DA in front of him to ask a question, so via him I was able to say "Hi and 'Thanks for all the fish'" or words to that effect of course, he also 'did' a lot of Doctor Who's in the late 70's and I owe him for that as well...

 

[Deleted member 48726]

Oh no! Iron core inductor!

CHEEESY!

 

[voodooless]

Oh no! Iron core inductor!

CHEEESY!

View attachment 326637

What of it? That's to ward off fairies!

 

[dfuller]

Oh no! Iron core inductor!

CHEEESY!

View attachment 326637

LMAO.

 

[Multicore]

Gotta commend Amir for the extraordinary amount of work that went into this one. A lot of lifting, debugging, correspondence, research, soldering, retesting, ... oh boy. And extra writing.

 

[Mnyb]

How does it measure with the towel