Jump to content

SGR Audio Owners & Discussion Thread


Recommended Posts

G'day,

I guess I thought there would be some kind of SPL roll-off towards the bottom of the frequency curve, so that anything below the stated minimum of 28Hz would be at much lower SPL, or even a hard cut-off at that point, rather than cutting out completely.

--Geoff

Unfortunately you just run out of headroom trying to do what you did. I doubt you would ever really run into the same trouble with musical content (unless your terry j or A9X or Chickenism etc.).

Subs away :)

Link to comment
Share on other sites



Right, you're the reason Stuart is putting my sub building on hold.... Have fun with your new speakers.

G'day,

Stuart is coming up tomorrow to tweak things, so I'll comment on the sound then.

One thing though: the kiddies put on "Finding Nemo" DVD and there's loud bass transients aplenty in that movie (submarines crashing against rocks, the fishtank tapping scene, etc). These transients caused the amps in the CX4F to go into protection mode about 5 or 6 times. Apparently the amps go into protection mode whenever there are very low frequencies at very loud SPLs. I'm not privy yet to the exact cutoff points for the CX4F in this regard, but using my crappy Radio Shack sound level meter I noted that the dialogue was around 65-75db and the transients up around 95db, and probably went down to 20Hz or lower.

I don't have a subwoofer, but I had to set a subwoofer cutoff point of 40Hz on the AVR (the lowest setting) to prevent the CX4F amps from going into protected mode. The rated specs of the CX4F are 28Hz - 20kHz, so it seems a shame to be losing all sound in the 28Hz - 40Hz range when playing movies (I haven't set any cutoff when playing music). I've not had to do this with any speakers/amp combos that I've used over the years (Rotel, Elektra, ME, VAF I-93, Orpheus Aurora III, Equinox Apogee, crappy JB HiFi floorstanders, etc).

Looks like I'm gunna need to get a subwoofer to fill in the bottom end for movie playback.

--Geoff

Link to comment
Share on other sites

G'day,

Stuart is coming up tomorrow to tweak things, so I'll comment on the sound then.

One thing though: the kiddies put on "Finding Nemo" DVD and there's loud bass transients aplenty in that movie (submarines crashing against rocks, the fishtank tapping scene, etc). These transients caused the amps in the CX4F to go into protection mode about 5 or 6 times. Apparently the amps go into protection mode whenever there are very low frequencies at very loud SPLs. I'm not privy yet to the exact cutoff points for the CX4F in this regard, but using my crappy Radio Shack sound level meter I noted that the dialogue was around 65-75db and the transients up around 95db, and probably went down to 20Hz or lower.

I don't have a subwoofer, but I had to set a subwoofer cutoff point of 40Hz on the AVR (the lowest setting) to prevent the CX4F amps from going into protected mode. The rated specs of the CX4F are 28Hz - 20kHz, so it seems a shame to be losing all sound in the 28Hz - 40Hz range when playing movies (I haven't set any cutoff when playing music). I've not had to do this with any speakers/amp combos that I've used over the years (Rotel, Elektra, ME, VAF I-93, Orpheus Aurora III, Equinox Apogee, crappy JB HiFi floorstanders, etc).

Looks like I'm gunna need to get a subwoofer to fill in the bottom end for movie playback.

--Geoff

Hi HG,

Sounds like you're having a few teething issues. I'm sure Stuart will have you up and running in no time.

Link to comment
Share on other sites

How'd the visit from Stuart go? Interested to know how it all went.

I can't imagine Stuart would be able to change anything though that you couldn't? For HT you need subs, thats the long and the short of it.

Do you have a particularly troublesome room ? I remember you sent the Equinox Apogee's back pretty rickety tick due to imagining issues if I remember correctly? Maybe a Integra DHC-80.1 + Audyssey Pro setup may help to overcome your troublesome room if that is indeed the problem :ninja:

Link to comment
Share on other sites



G'day,

So I had the SGR dudes turn up yesterday for some tweaking of the CX4F speakers. Some measurements were made and the tweeters and bass were dialed down a bit; now the speakers measure flat down to 20Hz. There's still an issue with imaging because I've got my TV sitting between the speakers and reflections are causing some havoc.

I'm running Squeezebox/Stello DAC and Rotel RCD1072 CD player into an ME15 preamp into the CX4F speakers. Also a Rotel RSP-1068 AV processor (for the Tivo, DVD, etc) is connected to the speakers. So the ME15 pre-amp not having a HT bypass is not a problem, since the speakers have two inputs that can be active simultaneously. Nice.

The sound is very good, the best I have heard in this room (previous speaker amp combinations: VAF I-93, B&W 805, Equinox Apogee, Orpheus Aurora III signature, ME550-II, Elektra Reference 2x250w, Rotel RB-1090 2x380w, etc). The bass is tight and deep, the midrange is clear, the highs are sparkling. There's been a few reviews already that I don't need to repeat. But ... the sound could be better, if I improve my room and sources. There was a wee GTG last night at the SGR Brisbane rep's house and the CX4Fs driven by the MSB pre/dac and in a bigger room with soundproofing showed just what the CX4F speakers are capable of. So now I know what to aim for when I make room or source changes.

Operationally, there a number of caveats. First, an array of six-inch drivers in a sealed cabinet is not capable of producing massive bass transients. If the processor in the speaker detects sudden loud bursts of deep bass, which would harm the drivers, then the amps will go into protected mode. The first movie I played with the CX4Fs was "Finding Nemo", which has numerous scenes with killer low-end. Normal dialogue was around 65-70db, and the bass transients were 20Hz @ around 95dB or higher. So the "submarine hitting the rocks" scene or the "tapping the fishtank" scene would cause the speakers to briefly shut down. These speakers are not meant to be played full-range for movies, so I had to set the subwoofer output on the AV processor to 40Hz so that the CX4Fs will not be sent any sudden low-end signals.

The only problem is ... I don't have a subwoofer :) Looks like I'm gunna need to get one eventually to fully enjoy moofies. I guess I've been spoilt by having very large and ported speakers and very capable amps that can handle such transients with ease. But these ported designs have not had the tight bass of the CX4Fs, so I assume this is the trade-off that needs to be considered.

Note that sudden, loud, and deep bass transients are not generally present in music, so the CX4Fs are still running in full-range for stereo use (the ME15 preamp does not have a subwoofer option anyway). I've had no problems playing any CDs very loud with deep bass, but I'm sure there must be a limit somewhere.

The second operational issue is the speakers will also go into protected mode when the power supply drops. So far this has happened thanks to a brown-out, and when I plugged the vacuum player into a power-point that was on the same circuit as the CX4F (and all the other AV gear). The lesson here is do not plug these speakers into a circuit that is already overloaded, although I think SGR may tweak the processor to handle such situations better in the future (perhaps by detecting when power is available again).

An associated issue here is "rebooting" the speakers; once the amps shutdown in such cases, one needs to toggle the power supply, either by turning them off/on at the wall or reconnecting the power cables at the back of the speakers. Neither option is WAF friendly (since the wall point is behind a cabinet in my case), and perhaps a dedicated "on/off" or "reset" switch on the back of the speakers themselves may be a good idea for future models.

I also had a chance to hear the CX3B standmount speakers again ... these are very nice speakers, and for some music that was played last night I think I preferred them over the CX4F. Standmounts just seem to have better imaging and produce greater clarity in vocals, IMHO. Of course, there's some missing bottom-end, but not that much compared to the CX4F (I think it was mentioned that the CX3B measure flat down to 35Hz or so in that room). If deep bass is not generally an issue for the type of music you play then the CX3Bs should be considered, IMHO. Of course, for HT use, a subwoofer is required for both and deep bass is not an issue any longer; just aesthetics.

So ... very happy with my purchase, but it does ruthlessly reveal the limitations in room and source that I have been avoiding lo these many years. Now to scour the classifieds ...

--Geoff

Link to comment
Share on other sites

A nice balanced write up Geoff. I take it room treatments are next on the agenda or is the subbie the go first?

Its funny but I always considered my demo room rather benign acoustically, and it is compared to most. But, $2k spent on basic room treatments made a huge difference in what the speakers were capable of achieving.

In the context of most systems represented on SNA $2k is not a substantial amount to spend, but I suspect the WAF factor is actually more important than the budget.

Link to comment
Share on other sites

@ Geoff

Thanks for the balanced write up. It is a credit to you.

For your listening space I can recommend David Spargo at Praxis Acoustics. I am a convert to targeted intervention for listening rooms - the idea is you basically want to do the least possible for the maximum benefit. David changed forever my understanding of small room acoustics. I spent under $1100 with him and Gordon from Acosutic Vision in Melb for some custom made specific band resonators strategically placed. The difference they made was huge. Like DSP but better. And very high WAF.

My experience is that any fool can take measurements (although there are measurements and then there are measurments) but knowing what to do with the results in a predictable and scientific fashion is an entirely different matter. That I leave to the experts.

All the best

Tricka

Edited by tricka
spelling
Link to comment
Share on other sites

Note that sudden, loud, and deep bass transients are not generally present in music, so the CX4Fs are still running in full-range for stereo use (the ME15 preamp does not have a subwoofer option anyway).

Some impressive speakers been through your household Geoff, good to hear the CX's stack up. The ME doesnt need a sub option, because the CX's have a low pass output. Integrating in a sub (or 2) will be a doddle for you for stereo usage, no messy external crossovers to worry about.

Link to comment
Share on other sites



Hi HG,

Thanks for the write-up and good to hear you're generally so pleased with the results.

With regard to room treatments, I have to agree with Tricka (good to see you back posting T) and say that room treatments done randomly and without a large amount of prior experience / training with some scientific knowledge is mostly useless. Harry warned me previously about this but I knew far better of course and spent ages making up some accoustic foam panels to stand around the walls at "strategic" points. They are now strategically placed in the back bedroom stored untill my next brainwave. The one bit I do use (if I can be bothered) is a plain piece hung over the flat screen to damp those reflections. - Not altogether sure if it does a great deal of good, but I think I can hear a difference.

Grimmie

Link to comment
Share on other sites

G'day,

The one bit I do use (if I can be bothered) is a plain piece hung over the flat screen to damp those reflections. - Not altogether sure if it does a great deal of good, but I think I can hear a difference.

Yes ... I might hang a rug over the tele to see if that makes a difference (or perhaps remove it altogether).

I will add one qualification to my mini-review above: I think the SGR CX4F is the second best system I've had in my room. The top honour goes to the previous version of the Equinox Apogee, which used the Audax Aerogel drivers. I had those speakers on demo for a week, using an ME15/ME550-II combo, and the sound was wonderful, spine-tingling at times. I've not had that same spine-tingling sensation ever again (not even with the new Equinox Apogees, which used different drivers). But I am confident that some tweaks to the room and the source will get it back ...

--Geoff

Link to comment
Share on other sites



Hi Geoff

I have not heard these myself but glad to hear you have been pleased with them

Having removed the crt from between the speakers myself, I can attest their is an improvement to be had there in imaging.

I'd definitely be recommending a sub for movies and heavy bass, for any speaker system of this physical size. I ran a sub on my 802d and they sung cleaner on music and vocals because of it (they had twin 8")

If the plate amps do have the crossover as mentioned above, that would be a good move. Just make sure it is a reasonable quality sub (which I'm sure you would)

Link to comment
Share on other sites

Geoff, I've done extensive testing with screen placement relative to speakers (because I've had to).

A blanket over the screen helps a lot in terms of high frequency smear but I've ended up with the screen set back 600mm to the speaker baffles. Screen in my case is a 40"er set dead centre between the speakers which are 2.7 metres apart.

At this distance imaging and depth are very good.

My screen sits on a swivel base and somewhat by accident I discovered that if you swivel the screen slightly and the imaging shifts, it isn't far enough back. I was actually very surprised at how much the imaging shifts even with the panel behind the focal plane.

Mind you, this was done only after I had removed the ceiling and side wall first reflections.

Link to comment
Share on other sites

Good morning HG,

Removing a large reflective and at times resonant television chassis from between and behind the plane of my loudspeakers has paid great dividends in terms of imaging and clarity. Of course, a large part of this is likely psychological but I also like the more purposeful look of the room now.

Pleased to hear that the new speakers are settling into your difficult room arrangement. Sometimes a more capable loudspeaker system places demands elsewhere in the system before one can realise its full potential. Addressing those needs, as you no doubt discovered at the Brisvegas mini-GTG, pays off in a big way and certainly gives you something to strive for over the next couple of years. In my personal experience the CX4Fs, or indeed any properly engineered loudspeaker, lap up all of the goodness that one can possibly extract from the source, being very revealing in this regard.... garbage in equals garbage out in other words.

Any movie soundtrack reproduction requires a dedicated subwoofer (or several) for the proper "effect" since no dedicated two-channel loudspeaker that I am familiar with was ever designed to move that much air without gross levels of distortion.

If the speakers are going into protection mode when your AC voltage sags then perhaps some sort of regeneration device would be worth trying.

As I understand it, active speakers do not have the luxury of caps in front of the drivers (passive crossover) to act as sacrificial lambs in the event of amplifier clipping so unfortunately extra safety measures are required to prevent a driver repair bill. Having said that I have never heard the CX4Fs go into protection mode, even at loud levels (90 dB+) in a HUGE acoustic space.

Cheers,

YS

Link to comment
Share on other sites

If the plate amps do have the crossover as mentioned above, that would be a good move.

Hey Norps, nice feature isnt it. Hasnt had much attention or discussion on the forum.

Here is the quote from the features page about it-

* Selectable high pass crossover achieves an acoustically aligned 40Hz LR4 response for use with a subwoofer.

* Subwoofer output, 40Hz LR4 low-passed with level adjustment +/- 6dB

http://www.sgraudio.com.au/products/convex/cx4f.html

Link to comment
Share on other sites

You are right Millsy, the integrated high pass sub out option on the CX series has not garnered as much attention as I would have expected. I often wonder how potent a pair of CX3Bs located in the extreme near-field (i.e. well into the room and pointed straight at the listener) with multiple subwoofers (each using two of the new SGR 12" drivers) placed around the room to give the most even measured bass response would be. Only one way to find out I guess.

YS

Link to comment
Share on other sites



I often wonder how potent a pair of CX3Bs located in the extreme near-field (i.e. well into the room and pointed straight at the listener) with multiple subwoofers (each using two of the new SGR 12" drivers) placed around the room to give the most even measured bass response would be. Only one way to find out I guess.

Very interested to hear the results of that.

I'm seriously contemplating a dedicated HT room with 5 x CX3B's , the front L/R/C channels hooked up to the X-men and a 3rd HT sub at the rear for the LFE channel. Dreams are free, but it's achievable for me, just gotta build the house first.

Link to comment
Share on other sites

G'day,

Do you have a particularly troublesome room ? I remember you sent the Equinox Apogee's back pretty rickety tick due to imagining issues if I remember correctly? Maybe a Integra DHC-80.1 + Audyssey Pro setup may help to overcome your troublesome room if that is indeed the problem :ninja:

Yes the room is troublesome, but that's not the main reason the Apogees went back. I had heard the original Apogees in my room (with Audax drivers) and they were sensational ... by the time I ordered a pair the Audax drivers were no longer available and new drivers were used; the sound, though close, didn't quite seem the same to me. In retrospect they still sounded fantastic in their own right, but in comparison to the previous version there was something missing. I would still highly recommend a listen to Equinox speakers if you ever get the chance (though I notice the price has increased quite significantly lately).

--Geoff

Link to comment
Share on other sites

G'day,

Yes the room is troublesome, but that's not the main reason the Apogees went back. I had heard the original Apogees in my room (with Audax drivers) and they were sensational ... by the time I ordered a pair the Audax drivers were no longer available and new drivers were used; the sound, though close, didn't quite seem the same to me. In retrospect they still sounded fantastic in their own right, but in comparison to the previous version there was something missing. I would still highly recommend a listen to Equinox speakers if you ever get the chance (though I notice the price has increased quite significantly lately).

--Geoff

I'd like to hear the new 3-way speakers when they are released. I'd use subs :wub: with them like I do know so there wouldn't be much point in looking at the models above that one. I've only heard the two way models to this point.

Link to comment
Share on other sites

  • 3 weeks later...

Hi All,

I have had my subs for many many months now and I'm acutely aware of their capabilities and limitations (though few). I thought I would take the time to share my experiences. I have always lusted over a pair of TC Sounds 18" LMS-Ultra 5400 sub-woofers but at US$1800 a driver I was never going to have them at this point in my life. Research lead me to the steal of our time being the Exodus Audio Maelstrom-X sub-woofers. Granted for $1300 plus you could build your own Maelstrom-X sub-woofer if you have the contacts and know how like hsv on this forum but I didn't have the time, resources or space to DIY. So I turned to my trusted friends at SGR to build the sub-woofers to my requirements and within my budget. Knowing this I contacted Stuart with regards to my requirements and he helped come up with a design that would achieve my goals.

Stuart and I came up with a design that was relatively small given the driver size but still had the performance levels I desired. Physics determines that you can only ever realistically have two of the following three; Small, Loud & Low. So given my constraints with regards to size Low was always going to be the one that had to give way. Thankfully though the Mealstrom-X is a ridiculously capable driver and even with a small box it is still able to provide silly output even below 20Hz. Modelling my driver and box size shows that it can produce 120dB of output about 25Hz and at 20-15hz and below it can still produce 110dB which is more than most sub-woofers can achieve at their peak. This is the only down side to my small sealed sub. Granted its only a very minor downside and the only real alternatives are to go LLT which triples the box size or go with passive radiators which doubles the price.

Now possibly I made a mistake when it came to buying the amplification the first time round due to the fan noise produced by the amps. I bought the Quest 3004 pro amp that can deliver 1100W into 4ohms per channel but unfortunately I found that the fans run constantly and when the amp works pretty hard the fans produce quite a bit of noise (even after the loud scenes have finished and you enter a quiet scene). As an aside, I was unofficially told by the Quest technicians that it can actually produce almost 2000W per channel into 4ohms as is it very underrated out of the factory. Even with 9dB of boost via Audyssey on my DHC-9.9 at near reference levels I never saw the amp light up it pre-clipping lights let alone the clipping lights. Seriously, the subs and amps were well within their operating spec even with lot of EQ and near reference levels. If you can put the Quest in a different room it would seriously be the perfect amp for running a pair of these subs.

Given my unhappiness with the Quests fan noise I began to search for alternatives. My search lead me to the either the Yamaha P7000S SII (2 x 1100W @ 4ohms) or a second hand Crown K2 (2 x 800W @ 4ohms). The beauty of the K2 is that it is passively cooled which means it has no fans, which = dead quiet. But the Yamaha is also dead silent until the amp determines that it really needs to have its fans kick in. From the various reports I have read the yamaha hardly ever has to have its fans kick and for most people they never actually do. Luckily for me I found a very friendly fellow on this forum to sell me his second hand Crown K2 at a great price. And so far I have not had any problems even though the amp is only rated to 800W a channel. That said Im currently not running any EQ as my Audyssey Mic died (no idea how or why). So its possible that with EQ at the extreme low end I could run out of steam, though time will tell.

My subs are my favorite possession now, I love them :) For HT and HIFI I find that great subs are absolutely paramount to having a fully immersive experience. Great subs really do add that extra level or realism that makes HT and HIFI so palpable. To get the most out of your system you need subs with lots of head room so that you can add that extra level or realism by EQ'ing out any of those room anomalies.

To sum up... I LOVE MY SUBS :)

Here are some pics of my system.

Excuse the flash making the grills see through on my mains.

Here are the subs facing forward without their grills on.

And here are the subs facing inwards where they sound and measure the best.

My subs cost me RRP $2k per passive sub.

If you were so inclined you could buy two Behringer EP4000 subs (+ fan mod to make them much quieter) to run these subs for the same price or less than a single Yamaha P7000S SII or Quest 3004.

Theres so many options.

I'm glad I supported an Australian company to build my subs when I couldn't do it myself.

Edited by Drizt
Link to comment
Share on other sites

Great stuff mate, as I can't get in on the Submersive GB I enquired with Stuart myself about having them build a sub for me and excellent to see your end product and possibly indicative of where I'm heading as well......

thanks for the pics as well..... B)

Thanks mate for the kind words. Hard to go wrong with the Maelstrom-X's :)

Link to comment
Share on other sites



  • Recently Browsing   0 members

    • No registered users viewing this page.




×
×
  • Create New...
To Top