"Official" Audyssey thread (FAQ in post #1) - Page 50

I am getting loud intermittent snapping/popping sounds during heavy passages from one driver in my dual driver dual ported sub. I am hoping it is only the coil bottoming, and not blown or loose coil wires.

I though adding a subsonic filter may stop the drivers over extending their travel (they really flap about during the passages that induce the snapping).

Can anyone recommend a filter? I could use my Behringer DSP1124P (parametric EQ). Also what effect would this have (phase, etc) when I re-run Audyssey?

It would be nice if Audyssey had a subsonic filter.

Is there any test I can do to see if the driver is damaged?

I agree. The Audyssey Pro results were much better than the original ones. I'm guessing a lot of this has to do with the better mike and boom.

Hi Nordo,

Man, we can't win. First people complain that Audyssey "kills" the bass and now you are complaining that we add "too much" bass.

Sorry..I couldn't resist.

My first thought is that you should figure out what's wrong with the sub. Trying to hide the problem with a subsonic filter is only going to prolong the misery.

Chris

im little confused with this...... if my speakers are crossed over at 150hz and my sub is at 80hz then what handles the freqency between 80 and 150? are they lost?.......seeing how the sub wil handle everthing below 80hz and the mains above 150.

The crossovers are not brick wall filters, the cutoff point is merely the point where the signal is typically filtered to half power (-3db). Depending upon the type of filter in use, the characteristic drop off could be either 3db or 6db per octave below this point.

To answer your question, the frequencies in between 80Hz and 150Hz are probably not filtered to a point where they are missing....just clipped

thank you, but can you explain that last part in english

and shoud i set the xover on the onkyo to 120?. that way nothing is lost?

As soon as you learn how to write a proper sentence.

I hope that was joke seeing how i was not talking to you. i just want to understand better, maby you can help me then? thanks.

I have 2 HTs with identical Rocket 7.1 speakers. I ran Audyssey Pro in both HTs (same rec'r in both), taking 8 readings in both. Obviously, the rooms are not identical.

In one, I thought Audysey was somewhat better than before. In the other room, it was awful; all the bass was wiped out.

Any explanations or suggestions?

This thread is rife with explanations and suggestions but, if you tell us something about the rooms, setups and your measurements, we might come up with something specific.

What are the results for crossovers and bass management for the second HT? Were the distances right?

The most likely reason is that in one room the AVR set the speakers to Large (or Full Band) and in the other it set them to Small. In the first case, that means that the receiver thinks that your speakers will handle the bass and sends nothing to the subwoofer other than the LFE track on the DVD. All the other bass content in the other channels is lost.

Having identical speakers is no guarantee that they will measure the same. It all depends on how they are interacting with the room acoustics. It's quite common that the same speaker is found as Large or Small based on where it is in the room, or what room it is in.

So, the first thing to do is to check the "awful" room and see if the speakers are set to Large (or Full Band). Different manufacturers uses different criteria to make that judgment. If they are Large, change them to Small.

Chris

Do you have gain controls on the subs? Were they set at the same level?

Hey, Chris.

When I ran the tests, I placed the mic approximately where the back of the chair is in the diagram. The first measurement was in my typical location, directly between the surrounds and about centered (I know, bad juju). The second and third were 6" to either side of location 1. Locations 4 and 5 were fore and aft of location 1 by 8 or 10 inches. Tests thereafter were done at various heights in the same few locations. All tests were performed with the mic mounted to a tripod.

As for the range of the bump, or bloat (what have you), I would say it's somewhere around 350-1500hz(pretty wide range, I know). Cellos and male voices are affected most. The frequencies above 3khz seem sort of muted, but that's fine, and the bass is cut, which I was expecting, so I ran the tests with the sub level a slight bit lower than normal and compensate by bumping it up a bit.

The center is in a cabinet. I removed the back panel and filled the cavity with high density acoustical foam. The center has always seemed sort of chesty to me, and I prefer to have its level down a couple dB from the mains. Audyssey also set the XO at 70hz, which I changed to 90. That helped the center a little, but it still has a bit more chest than I like.

I would say my problem is most disturbing with music in Stereo mode, but dialogue in movies is also given the cardboard box treatment.

I use Neural 7.1 when I watch BluRays on my PS3, but the effect seems to be universal to all modes, excepting direct and pure audio, of course.

A little more info, if it helps:

Room dims: 14X12X8
Speakers are 30" from rear and side walls, toed in.
Main first reflection points are treated with foam. The center is also covered by these treatments.
Speaker compliment listed in sig line.


I hope that's enough info to reach some sort of conclusion. I am working at getting an analog sound card (mine's digital only) so I can run some sweeps and get some FR graphs. That way, I can at least be sure there's even a problem, and it's not just me.

Thank you very much. It's great that you support your product this way, very cool indeed.

-Randy

Sorry for any confusion, most folks here read the AV mags which contain a lot of these types of graphics for speaker response. The way that the speaker crossover networks operate is to smoothly decrease the 'loudness' of the speaker the further the frequency gets from the cutoff frequency. If you are dealing with the reciever and have set your recievers' front speaker cutoff frequency to say 80Hz, frequencies below 80Hz will be sent to the subwoofer or LFE channel. Now even though your reciever is sending information below 80Hz to the subwoofer or LFE channel, some of the music information (from about 60hZ to 120Hz for example) is still going to be sent to the front speaker. As the frequency gets closer to 20Hz (two octaves lower), more of the low frequency music is filtered and sent to the sub/lfe channel.


This depends upon the frequency response of the speakers you are using (their size). Most speakers can be crossed over in the 80 to 100Hz area and sound fine.

Other than matching volume levels, should I need to do anything else but run Audyssey after attaching a second sub to the 885's single-ended subwoofer output (in addition to the one connected to the balanced output)?

TIA!

Randy,


You should really spread the measurements out a little more. Don't get fooled by the single seat. To capture good data (especially for bass) around your seat you should start where you do now, then go to the left and right about 2 ft. Then go forward about 2 ft and take three more parallel to the first three. The last two can be about where the front of the armrests are.


"The bass is cut" is usually a subjective call that happens when you are used to listening to bass with a big bump around 40 Hz in a small room. You are welcome to bump it after the fact, but I would suggest doing it in the trim of the receiver rather than the back of the sub. That way you know how much you bumped and can always go back to the flat setting.


Yes, I suspected that from your original description. The foam won't do much and in some cases may make it worse. Try to get the front of the speaker as far out of the cabinet as possible.

Chris

Using the standard pink noise from the onkyo receiver, I've listened carefully to each driver of the offending sub, disconnecting each one in turn. I also listened to both drivers of my other sub. I can't hear any difference apart from maybe a slightly "rougher" sound from the two drivers in the offending sub (could be my imagination).

I then turned the amps up full volume for each sub (amps are Parapix 50w stereo sub amps) using the pink noise, but could not induce any unusual sounds (including snapping), or any extreme cone travel - not like the extreme travel and snapping I was getting listening to a DVD with Audyssey on (and the sub volumes set at less than 1/4). .

Just a thought here - 50 watts seems to be a very small amp to drive a sub. Depending on your room size, I can see how it would be very easy to overdrive and clip the amp and causing "snapping" and all kinds of disturbing sounds.

Is it worth hiriing an installer to install the Sound Equalizer or is it easy enough to purchase the kit and install by myself?

Not sure how much the installers are charging.

Chris, I have a 7.1 system in a dedicated theatre (link in my sig gives you an idea of layout and room dimensions). The room treatments were designed by a pro so they should be significantly better than the average living room. When I ran mine, I got large all the way around. While my front towers I can understand, I was pretty surprised that my side and back surrounds showed up that way. Anyway, I set everything to "small" and changed the x-over to 80. I was concerned that the measurements would then be rendered invalid. Does the Audyssey compensate based on the changes I make *after* calibration, or do I need to re-calibrate after making changes manually?

I also have a BFD on my Sub so still trying to figure out how to make that work. Like others my deep Bass is gone. I'm guessing its because it killed my house curve. I see that question has been asked before though so I'll have to go back and see what those folks ended up doing. Sure would be nice to be able to define a house curve slope.

Audyssey Pro Setup...I have an appointment set up through my dealer to send a tech out to do a setup. The cost is $500. Part of that is travel to my location which is about an hour away. This covers the license agreement, software printouts and tech time. The one question I have for Chris and or others is that the dealer said that he would use 3 locations to do the setup. Is that enough? I have an Integra dtr 8.8. I have setup 7 points with the on board audyseey presently. Actually, it sounds pretty good and I am wondering if I sould expect a noticable improvement with the pro setup and if I am getting appropriate service for a $500 fee. How many points should I request for a normal pro setup? My room is a rectangular shape about 20 x 24 with a couple of nooks. It is a 7.5 ft. accoustical ceiling...soft carpeting and furniture. I have a 7.1 setup using def tech for all my speakers, but two paradigms for my rear backs.

(guy w/ 2 identical Rocket 7.1 systems HTs: different Aud. Results)

In answer to the questions above
1) Distances were correct.
2) In both HTs, ALL spkrs. came out Full Range; had to set Xovers on ctrs and surrs.
3) Sub gain set to same level in both.

A wall is like a very large speaker baffle. A baffle so large that its length and height dimensions will usually encompass the same lengths (and half-lengths) as most bass frequencies. Therefore, put a surround speaker On a wall and, through the phenomena speaker designers call baffle gain it is quite reasonable to expect Audyssey to hear the wall-assisted bass gain from the (direction of) surround speaker. Stick a speaker Inwall and you'll usually experience more efficient coupling to the wall (and perhaps even more (free) baffle gain.

So Audyssey's measurement, hearing the speaker as Large, is correct. It's just that Audyssey can't tell the difference between how low the frequencies are, emanating from the actual speaker itself, and how much (even lower frequencies) might have been generated by the wall.

That's one of the reasons why 80Hz has always been a great go to target frequency to use. As a speaker designer a rule of thumb I like to give is to stick with surrounds with mid-woofers at least 5.25 in size. A 5.25 is the smallest driver which will usually get down to ~80Hz in a well executed on-wall or in-wall design.

This is the reason why, whenever I'm doing an Audyssey calibration, I set all surround speakers to 80Hz for 5.25 (and larger 6.5" and up drivers) and 100Hz for smaller (4" and down) surround drivers.

Chris,
I have a Sound Equalizer and calibrated my room last night. After first measurement I got the message that all of my satellite speakers are out of phase! I checked the connection, everything is setup correctly. Any idea why I got that message? I finally ignored it and went on with the calibration.
Tomec

He should be doing a lot more than 3 mic locations - they must learn that in Audyssey Pro school. For 3 seating locations, he should probably be doing more like 12 mic positions.

If I want optimize only one seatng location, which is located off axis, how many mic positions is required?

How far off axis? Remember, you don't really want to be outside the positions of your fronts, or even too close to that, so you can take measurements to your sides and still stay inside your front positions. If that condition is satisfied, I'd do at least 5, the first at your primary location, two a couple feet in front and spread 2-3 feet apart, and two a couple of feet to each side. That would be a minimum - you could do more, as Chris suggested a few posts back.

Front speakers are 7' apart. I am sitting 1.5' away from the right speaker.