# Underwhelming bass issue



## LastManStanding12 (4 mo ago)

I have a 5.1.4 setup inside my 45m3 sealed bedroom. Sub is svs pb-1000 pro. I usually watch movies with master volume at -15 below reference. My target is accurate bass - staying true to the creators' intent, and I currently feel that the bass at my listening position is not how it should be. Chest slam bass is satisfying enough, but supposedly-seat-shaking feel-more-than-hear type of bass like explosions or earthquake is kinda muted.

I moved the sub to all possible locations around the room and did some REW measurements for the LFE channel. Below were the best ones from the bunch. They were all pretty bad, but since 1. the port tuning frequency were around 24hz so any attempt to later boost the 20-30hz region was a no-no and 2. I wanted that sweet ultra low bass, I decided to go with the BLUE one as it had the most output below 30Hz.









Then I ran Audyssey. This was before (ORANGE) vs after Audyssey (BLUE) for the front left speaker (calibrated to 75db, master volume = -15, sub gain -15 in the svs app):









After doing some eq using the built-in parametric EQ of the sub and enabling Dynamic EQ, this is what it looks like:









With 1/12 smoothing, not too bad. Kinda like a house curve from 81db to 76db:









What am I doing wrong here?

Any advice is welcome. Thanks in advance.


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## Da Wiz (May 8, 2019)

Just for the record... I find "Audyssey suound" worse sounding than manual EQ with a $50 analog sound meter or a $150 USB microphone about 50% of the time. Sometimes remeasuring with slightly different mic positions will improve the sound, but sometimes that doesn't happen. So don't assume every Audyssey run will sound better than not using Audyssey... because Audyssey is not automatically better all the time. I would walk around the room making REW measurements through the bass to find out if your main seat is in a location that causes a suck-out at the main seat.

AND... if your AVR/processor has "high pass" and "low pass" filters for the subwoofer, make certain that the high-pass is set somewhere above 100 Hz... 150 to 200 is common. And if there is a low pass filter, make sure it is set to OFF or whatever the lowest value is. If the low pass filter is set to, say, 36 Hz, it will roll-off the signal going to the subwoofer starting at 36 Hz and getting weaker as the frequency gets lower. 

Either of these issues can limit the low bass capability. Also... ZERO port plugs will provide the lowest frequencies but the highest distortion. Many people find that leaving 1 port open and 1 port closed provides a good compromise for deep bass and low distortion.


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## RichardTS (May 15, 2014)

I have had total Audyssey failures resulting in zero bass. Every single time it was microphone placement. I now use a tight mic array very similar to that shown in the Denon manual-rectangular about 6’ on the long dimension and 2’-3’ centered on the listening position. Almost always get smooth, accurate bass. I have done this in 3 houses with completely different and complex wall arrangements. If more bass is needed (almost never) I can tweak it with sub levels either through the app or with the level knob on the sub.

Equalizing with Audyssey also sets group delay which cannot be done with a simple level analysis. Note that Audessey is setting the distance using actual sound arrival which may not be the same as physically measured.

So I recommend sticking close to the manual. My success may also be related to being an old high ender using amps with no tone controls (dead flat).

Accurate sound is not always what you think it is and your mileage may vary.


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## theJman (Mar 3, 2012)

Once it was switched to 1/12 - what most people use - the results look very solid if that's the MLP. The dip around 45Hz prior to the change in smoothing was ugly though, that's a huge null.


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