Seaton Sound SubMersive1 - Page 162

Agreed, and much too early to be speculating about ... mis-behavior, n'est-ce pas?

Does anyone see anything there that could be related to the protection circuit triggering?

A separate issue I suppose. I'm still trying to get over buying a Submersive HP for a spot two feet from the LP.

Feel free to go ahead and get over it.

Craig

Probably just needs to buy a Pro and tweek something 1/2 db.

Hi Jeff,

The PGM 1 vs 2 curves won't tell us anything applicable. We would need a before/after Audyssey measurement extending to at least 10Hz and likely lower to see more of what's going on.

My question was if Audyssey will flag the signal as out of range/too loud and not run the test until you lower the level.

Looking at the measurement I posted as an example:


Imagine this being the difference of setting your "flat" target level to 100dB on the above graph vs. setting it at 90dB. Both can be made flat by different methods. Only Chris from Audyssey could answer how Audyssey handles it. It could just as well be some dip way down low (ie <14Hz) being boosted a bit too much, but note we haven't yet found the problem without Audyssey engaged.

I also find the -12dB sub channel and -34dB SubMersive level to indicate that the correction processing is applying too much gain.

Mark,

I just want to be sure we're clear... the -34dB SubMersive level was *before* any correction processing, and with the Integra's subwoofer trim set to the factory default of "0". The trim was set to -12 *after* the Audyssey run.

When we first hooked up the Submersive, I set the level to -24 to mimic the setting on the previous amp. The subwoofer trim was at the factory default of "0". We put on some music just to see if it worked; I believe it was "Tool", (although I must admit that I'm not very familiar with that genre of music. ) The bass with so incredibly loud that I was afraid we were going to blow the sub. It seemed like it was at least 20 dB louder than the speakers. Therefore, I was not the least bit surprised when we had to turn it down considerably to get it even close to being in range. And because we were still "above range" before the Audyssey run, I was even less surprised when the post-Audyssey trim setting was deeply negative, (-12).

Mike sent me a copy of your IM's from earlier today. I will try to get back up to Mike's and help him with a new Audyssey run with your suggestions. Hopefully, turning up the Submersive gain and ignoring the pre-Audyssey level settings will still allow Audyssey to run. Then, hopefully, it will find that big peak at 45 Hz and reduce it. And then, hopefully, this problem will be behind us.

BTW, my measurement system is only calibrated to 16 Hz, so I can't show you anything below that. Sorry.

Craig

How about buying an HP and having it 1ft from LP
Been loving every minute of it too

Mike,
It sounds like Mark may have nailed it but please keep us updated on your progress. For reference, our rooms are very similar in size, mine is slightly bigger (only by ~100 cu. ft.) and is not sealed. My receiver has Audyssey but I chose not to use it as I prefer the sound of my mains without Auydessy. I use AntiMode and then calibrated my system using the DVD Tool Kit supplied with the Submersive HP and a RS SPL meter. The receiver sub channel is set to -5 and the SubMersive HP volume dial is set on the notch between 24 and 16. The SubMersive measures the same db as the mains speakers so I am probably 1-3dbs hot.

I tried reference levels a few times and only ended up scaring myself I usually listen to movies between 9 to 16 below reference. My SubMersive HP, 50inch Plasma, BR Player, Ps3, Lights, Fan, Onkyo 805 Receiver, HD-dvd player and Dvr cable box are all plugged into the same 15amp breaker with no issues.

Mark et al,

The -12dB and -34dB settings, trim and gain respectively, are what was needed by the 80.2 to balance the sub with the other channels. I'm not even certain that the corrections made by Audyssey are figured into it. I seem to remember reading that Audyssey's corrections are .. struggling for the right term here ... level-neutral over the band reproduced by the individual channels, be they main or sub, so that there is no perceived loudness change when turning Audyssey on and off. In any case, the efficiency of the mains enter the calculation on what the gain and trim is on the sub channel. Also, maybe it is the honkin' sub in a small room TWO FEET from the main listening position that "is applying too much gain."

Jeff

-34 was pre-Audyssey, -12 was post Audyssey.


The "right term" is "unity gain".


Really? I'm not sure that's so. I think the sensitivity and room reinforcement of the mains is used to set the trims for the mains, but I don't think it has any bearing on the subwoofer trim.


I know what you're saying, but the previous amp was only set to -24. Maybe the Integra is putting out a higher level signal than his previous preamp. Either that, or the input sensitivity of the new HP amp is different than the previous amp, (which doesn't seem to be the case based on my experience with my 3 HP amps.)

Craig

Hi Craig,

I wouldn't expect the levels from the old amp and system to correlate as the DSP-30 was in the chain and has settings for input and output gain and was attacking that huge mountain at 45Hz.

In case there is any confusion, I believe you followed procedure as Audyssey would have you and did a very nice job setting the system up. The small squarish room just managed to throw a curve ball for one of those cases that doesn't always work out as planned. I have encountered related issues myself, and it took some probing and experimenting to sort out solutions (not to mention a lot of burnt time!).

Isn't the -34 on the sub and the -12 the trim on the 80.2?


Grassyass.



OK, ya got me there. The efficiency of the sub and the sensitivity of the sub amp play a role.


Well, there is certainly something very different.

Thanks Jeff,

If that is what Audyssey has indicated their system does, that corresponds to what I suspect is going on. It sets the level before EQ, and then flattens the response. If you look at the vertical scale on the measurement I posted, an SPL meter with a pink noise test signal would approximate the level of the subwoofer at about where the 100dB line is, so everything below 40Hz would be viewed as 5-10dB low in level from a target curve and a modest peak around 45Hz.

It really is just a matter of the perspective (ie frequency range) from which level is set and EQ is applied.

WOW. Thanks for all of the feedback guys(Mark, Craig, Jeff et. al). I really appreciate it. I knew I was taking a chance by getting this amp. And I know I might have been a little crazy to put a 2400 watt amp in a room that is closed and just about 1000cf. But I wanted to give it a try. Getting measurements down to 10hz may help or it may not. But I think a pro cal, because it seems to be more sophisticated may be a good thing to try. Hopefully Craig, and Jeff can find time to maybe stop back and "trouble shoot" some more. Craig, Dennis, Jeff and Mark have already gone above and beyond helping me with all of my setup issues.

Knowing the response and that the -34dB Volume knob setting on the SubMersive was showing 80-83dB at zero dB, the -12dB setting indicates to me that the magnitude correction applied by Audyssey included significant gain on either side of the peak to smooth the response, and it is the gain applied behind the scenes that I am suspect of.

Hi Mark,

This is exactly what I encountered when using Audyssey.

The graph below shows:

1) The bottom of the graph shows the measurement at the LP, before and after Audyssey. Although the response shows the peak was flattened, the sub was suddenly (and unexpectedly) running very hot, with considerable boost across the entire sub BW.

2) The traces at the top of the graph are close-mic. You can see that, instead of pulling down the peak, Audyssey boosted either side of the peak. The purple trace is the close-mic without Audyssey and the green trace is what Audyssey did to smooth the response:



The result was a +7dB bump in SW level. Had I been watching a movie like WOTW at reference level, or with the SW level running hot to begin with, it would have been somewhat noticeable.

Bosso.

That's great stuff Bosso! Close mic'd with Audyssey on and off: that is exactly the kind of analysis I suggested earlier:

I will definitely look at that when I get back to Mike's place. Thanks.

Craig

The measurement that Craig made show the Submersive's response in Mike's room to be fairly flat, but why are we assuming that Audyssey boosted the lower parts to match the higher? Anyway, MultEQ XT has a max boost of 9dB so that wouldn't account for it. If the areas on either side of the hump were nulls, they would not have measured flat after equalization. And beyond that, I don't see how equalizing to flat a sub as capable as the Submersive could result in this problem if it wasn't nulls that were attempted to be corrected.

Jeff

I'm thinking very seriously of buying a Submersive, and have been reading this thread extensively doing background research.

All this talk of Audyssey and room EQ and MikeDuke's problems has got me a bit spooked I'll have to say.

I wonder, does anyone have experience with Submersive and Yamaha amps? I have an RXV1700 with YAPO (Yamaha's version of room EQ). Should I expect that this will work similarly to Audyssey? My room is 3000 cf, with a 5' arch to more area (say another 1600cf). It has wood floor and no acoustic treatments. I will be colocating the sub behind one of the mains next to the entertainment unit near the arch. The sub will be about 12 feet from the main listening area. I know nobody can predict room response, but should I expect to get a good outcome with the Submersive in such an environment with only the Yamaha YAPO EQ to help me dial it in (e.g. no pro install)?

Just to list the rest of my system, I have PSB Synchrony One mains and center, and currently some older non-matched surrounds that have yet to be upgraded.

Am I correct in assuming a single Submersive HP is not too large for this room?

Any suggestions of other tools I might use to setup the system. I have no end of computers around. Any software that might work. What makes all those pretty graphs everyone posts? Is that an output of Audyssey?

Thanks,

-Jim

Did you take measurements that showed the sub channel was 7dB hotter after correction than the other channels?

Jeff

Mike's "problem" is unique, and is due to the highly unusual settings he has to use in his room. I would NOT let it hinder your decision about getting a Submersive. If you have YPAO, you won't have any of these type of problems because YPAO doesn't do anything to the subwoofer.

No such thing as a sub "too large" for a room.

I use xtz Room Analyzer to take my measurements and post those "pretty graphs".
http://www.xtz.se/uk/products/mearur.../room-analyzer

Craig

Jim(heckhecK) I will say this as plainly as I can. Do not let my experience sway you from getting a SubMersive HP. There are plenty of them in the wild(with people using Audyssey) and I think that I am THE ONLY person who has reported this. I am unique. BTW it is not an overall problem. I have watched many BR and regular DVD's. WOTW is THE ONLY movie to do this. Please don't let that one time event prevent you from getting this fantastic sub.

Yes, you are!

Craig

Only if you are willing and able to act on the measurements by moving the sub around to the best (read: least worst) location. Without any EQ/correction on the sub channel, it's just academic if you don't experiment with sub location. IMO.

Jeff

Good to know. I'm just concerned with a lack of EQ in my amp for the sub, that the room might be hard to tame. Would you think there would be any glaring deficiency if I decided to put the sub right next to an arch, like this? One of the drivers would face towards the arch, the other towards the E. Unit (6" gap). The main room is 27x14x8 (3000cf) the area beyond the arch is maybe 1000cf and then another arch to more.

I've also read about some free software, and there is a disk Mark gives away with the Submersive, would that be sufficient? Without sub EQ, would there be much point to trying to map the room response?

Thanks,

-Jim

Sorry, that was me. I accidentally double posted while fixing my ascii art. I deleted the first post to clean up after myself.

-Jim

Don't think so or it would not be part of the guide put together by giomania et al that includes a step to initially do a one-position/measurement setup to check that sub channel trim is within range.


I honestly don't know what their approach is, but I can't imagine that there is not both boost and cut applied. I have read that they match the filter level between MultEQ on and MultEQ off in the 40 to 80 Hz range. So to the extent that their algorithm satisfies that condition, maybe there is more boost than cut in this instance.

This looks to me like a situation where some acoustical treatments are needed to tame the room a bit, i.e get it "within range, so that electronic correction can polish it off. If Mike had the option of changing sub location, then that would be preferable.

Jeff

Jeff, you probably have already but if you click on the "my system" link you can see what treatments I already have up. Start on page two. I can tell you though I have two GIK 244's on the back wall. Two 244's over my head. Two 242's on the front wall and 2 Tri Traps in the front two corners. I have a window on one side and an closet on the other so it makes it difficult to put anything of substance there. I might be able to find some long and thin treatments to go above there but I am not sure how effective they would be.The one spot I can do with out an issue is the front part of the ceiling. I have a ceiling fan so I have a pair or traps behind it. I could always put two more in front of it. Beyond that I might be able to get two more behind me if I get them custom made. But then I don't want to over do it either.
I think as it is, my room measures and sounds great as it is. My RT times is very good and the other charts that Craig did for me showed that I am in a pretty good spot room wise. I am not sure I want to do anything that would alter it much more.

Hi Mike,

In the context of this thread, I am referring to bass traps when I say "acoustical treatments." I'd start with extending the existing corner traps from floor to ceiling. In fact, it's nearly impossible to have too many corner traps, so I'd recommend filling all four wall/wall corners with them.

My $.02.

Jeff

I understand but that is simply not possible with the room I have. In the front of the room I have my two racks very close to the front corners so I can only put traps from the ceiling half way down. My door opens right into the one of the back corners so I can't put anything there and my sub is in the other corner. So I can't put anything floor to ceiling traps there either. Not trying to be a pain, that is just the limitations of my room. The one thing I might be able to to is get two of these
http://www.gikacoustics.com/gik_elite_pillar.html
and put them behind my front speakers. They are 48in tall and my front speakers are 42in tall so I would see if I could get them at 40in tall so they do not tower over my speakers. That is really the only thing I could do for both front corners. The back would have to stay as it is.