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Post by chambers1517 on Jan 21, 2012 11:13:56 GMT -7
I finally have my IB complete and somehing isn't right. When I run Audyessy I hear the test tone for the sub. With both volumes on my EP 4000 maxed I get 85 dp. Does this seem weak for an IB with 4 FI 18's? When I turn either channel down I lose about 10db. Each pair of subs produce the same output and both pairs together produces more so I don't think it is a wiring issue. When Audyssey get's to the sub I get a speaker error. The room is empty with no furniture so maybe it is an echo issue but the other channels are ok. I have moved the mic all over the room and the sub trips it up everytime.
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Post by jman on Jan 21, 2012 12:58:08 GMT -7
85 spl? Relative to what? How are the ib drivers wired, what mode is the amp running in? Are the drivers all in phase?
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Post by ThomasW on Jan 21, 2012 22:25:49 GMT -7
Does the ouput voltage from the subout have adequate drive level for the EP4000?
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danny
New Member
Posts: 9
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Post by danny on Jan 21, 2012 23:42:44 GMT -7
My marantz audessy lowers my sub output as well. I have to go back in and manually raise it. You might have more than 1 sub gain setting... , mine has an overall speaker gains, plus different ones for the sound modes. thx, dolby ect..
Also when playing 2 channel material (cds, mp3s) the surround modes like thx and dolby give me no sub output whatsoever. multi channel music and multi channel movie are the only settings that give sub output when playing 2 channel.
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Post by chambers1517 on Jan 22, 2012 5:52:40 GMT -7
Thanks guys. It ended up being my fault. The reciever sets how many speakers are being used. For some reason you have to set how many subwoofers manually. It was set for 2 subs and I am using only one output. This is what was hanging it up. We watched a movie last night and WOW. Is there anything to gain by adding my BFD or has Audyessy got it close enough? Thanks for this forum. No way could I afford a sub with this kind of performance. During one scene last night if felt like our chairs were being lifted off the floor. The kids started cheering and my wife gave me a " are you serious look".
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Post by thedude306 on Jan 22, 2012 7:02:38 GMT -7
During one scene last night if felt like our chairs were being lifted off the floor. The kids started cheering and my wife gave me a " are you serious look". That's gold! I can't wait for that look! Is there anything to gain by adding my BFD or has Audyessy got it close enough? I don't think there has been enough testing done with an Audyessy system, or at least I haven't found any. It looks like XT32 should be enough if it is doing it's job but I haven't found any results using an actual IB or anyone taking measurements with an IB and XT32 I would start measuring and make your decision from there. |
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Post by FOH on Jan 23, 2012 9:20:16 GMT -7
I'm not much for automated EQ rigs, however I've seen several very significant subwoofer systems, for HT, that have had very good results by merely utilizing Audyssey for EQ'ing the system. I've also seen where an automated system (maybe Audyssey) performed wildly large amounts of un-needed EQ, seriously restricting a system's headroom un-necessarily.
It can be done, but I overwhelmingly prefer to EQ myself.
YMMV
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Post by ThomasW on Jan 23, 2012 11:12:52 GMT -7
I'm not much for automated EQ rigs, however I've seen several very significant subwoofer systems, for HT, that have had very good results by merely utilizing Audyssey for EQ'ing the system. I've also seen where an automated system (maybe Audyssey) performed wildly large amounts of un-needed EQ, seriously restricting a system's headroom un-necessarily. It can be done, but I overwhelmingly prefer to EQ myself. YMMV +1 As time progresses the automatic units are getting better and better. Thing is the really good ones are $5K. Personally I think the $150 FBQ2496 is the way to go.... |
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Post by FOH on Jan 23, 2012 14:00:58 GMT -7
Personally I think the $150 FBQ2496 is the way to go.... Great advice, and puzzling that with the comprenhensive tutorial provided in the FAQ/etc., that more individuals don't go with it  |
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Post by severianb on Jan 25, 2012 21:01:39 GMT -7
Wow, you guys are showing your age.  Audyssey XT32 is a incredible system that makes the old parametric stuff you are promoting look like a sad joke. I know listening is subjective, but the before and after plots match what my ears are telling me: MASSIVE IMPROVEMENT. Get with the times. Next thing your going to tell me is big full-range speakers are better than any subwoofer system is for music.  |
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Post by mtbdudex on Jan 26, 2012 6:21:24 GMT -7
I have great respect for ThomasW and FOH.
There is no "right" answer.
If you have "just" audysseyXT, then it may not be enough and basic PEQ can give it a good start.
I've seen posts where audysseyXT32 with its many more filters does such a great job that PEQ not needed.
My take;
All rooms need some broadband bass traps to bring modal decay times down and help flatten the response.
Then, apply the EQ. If you have audyssey/etc, try it alone and measure, if that is sufficient, great.
If not, possible PEQ + audyssey can solve the issue.
Possible the room may need specific bass trap at the trouble freq (membrane, etc), lots of variables.
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Post by FOH on Jan 26, 2012 10:59:13 GMT -7
Thanks for the kind words Mike.
Audyssey can be helpful, or it can easily be destructive. There's many ongoing, current discussions right now regarding how unpredictable Audyssey is in the lowest octaves. It can easily create boost amounts of 10db below the knee, and as low as 7-10hz, thus entirely using up all headroom, and bottoming drivers unsuspectingly.
The issue is an algorithm sensing system for the lower end roll off of a system. Results can be solid, however it's unpredictable at best. I will concede the two channel component, whereby two independent subwoofer channels can be EQ'd in both freq and time domains is a great step in the right direction for many users. Still, being mindful of the amount of infra boost applied is of paramount importance.
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Post by thedude306 on Jan 26, 2012 19:00:50 GMT -7
sorry, not of an IB but I got my SPL meter and REW hooked via my MPB and made my first graphs tonight. XT32 makes a difference. Whether that's good or bad I have NO idea. What do these two graphs tell me? Macbook Pro, Denon AVR4311, conected via optical cable, RS SPL calibrated in REW connected via RCA line in, M&K MX125 push-pull dual driver in a 12x28x8 room. AVR set at -20db Near field measurement. Top line is with XT32 off, bottom with it on.  in the main listening position. green line XT32 on, purple line it's off.  |
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Post by chrisbee on Jan 27, 2012 0:37:08 GMT -7
Hi Brad The first plot shows a 10dB difference in output but no obvious improvement in the shape of the response. The changes are so small as to go unnoticed on real programme material. A change in REW smoothing would have far more effect on the curves. (without changing the sound one iota) The plots in the second graph are so similar that it would be difficult to choose which is better. On the face of it nothing useful is happening with the EQ switched in. BTW: REW users have settled on standard graph limits of 45-105dB vertical and 5-200Hz horizontal. Using these limits makes it easy to compare and analyse different graphs. There is a box top right of the REW work page to change the limits and apply them. EDIT: Test at a nominal 75dB. Preferences > Check levels > Next > Finish.Testing at unnecessarily high levels causes all sorts of problems. Not least increased domestic strife! |
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Post by thedude306 on Jan 27, 2012 8:19:26 GMT -7
thanks for the tips. I will turn down the DB to 75. My wife will be happier with that!
I will also spread the field out to 200hz.
I find it quite interesting that I can now take measurements, and by how such a small movement of 6" can create such a difference in peaks and nulls.
With out this forum, I would have never ventured into taking room measurements or finding the equipment to do it.
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Post by FOH on Jan 27, 2012 9:29:11 GMT -7
Chrisbee, to me, the first graph has some decent smoothing, especially when considering the 10db vertical axis. In addition to other smoothing, a 10dB swing was eliminated between 40-50hz. Not too shabby, actually, the second trace appears more akin to a typical close mic measurement. Never seen a close mic, Audyssey on, then off, measurement. Dude; was the Audyssey manipulation performed at the LP for the LP graph, or close mic? It appears the latter. If so, then a do-over is in order, for the LP. Have fun and be careful with all measurements.  |
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Post by chrisbee on Jan 27, 2012 9:30:20 GMT -7
thanks for the tips. I will turn down the DB to 75. My wife will be happier with that! I will also spread the field out to 200hz. I find it quite interesting that I can now take measurements, and by how such a small movement of 6" can create such a difference in peaks and nulls. With out this forum, I would have never ventured into taking room measurements or finding the equipment to do it. The testing, or listening position, in any room is always related to frequency which is related to wavelength. We can use this to our advantage to get the flattest response in our favourite chair. If the room is fairly quiet, without people crashing about or heavy traffic you can try reducing the REW test levels even further. I have even done REW tests in the ad breaks while my wife was watching TV. She muted the TV while I ran sweeps.  If you want repeatable graphs at very lower frequencies try the longer REW sweeps. Up to 1M seems to improve the results. There is a box to change sweep length and breadth in the REW "Measure" sequence. The worst part about visiting this forum is spending far more than you ever intended. This must be resisted at all costs!  ThomasW is personally responsible for there being at least 5 extra boxes in my rack. I now have more cables than most telephone companies. I even started buying organ LPs and now have over 50! He made me do it!! ;D |
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Post by chrisbee on Jan 27, 2012 9:37:56 GMT -7
Chrisbee, to me, the first graph has some decent smoothing, especially when considering the 10db vertical axis. In addition to other smoothing, a 10dB swing was eliminated between 40-50hz. Not too shabby, actually, the second trace appears more akin to a typical close mic measurement. Hi foh You may be right. You usually are.  With the standard vertical scale 45-105dB the changes would probably be far more visible. With the present stretched scale the changes are visibly reduced. So there may still be hope for this new-fangled, XT32 after all! |
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Post by severianb on Jan 29, 2012 19:35:57 GMT -7
So there may still be hope for this new-fangled, XT32 after all! XT32 is the latest generation of a EQ system that's been developed for 15 years at the expense of millions of dollars, as you know. I'd hope it would do something good. As an aside, the Frequency response graphs only show part of what Audyssey does. As others have said above, I use a mic and REW to get things roughly set up, then let Audyssey take over from there. |
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Post by jman on Jan 29, 2012 21:29:04 GMT -7
But what does Audyssey do that we can't do manually with our sad PEQ's?
Audyssey claims they can correct in the temporal domain, which is a load of horseshit. Is audyssey better than nothing? Maybe. Is it better than everything else? Pfft.
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