My horrible living room

Wow..

I finally got a chance to play with REW yesterday and today. I knew living in an apartment where the living room is open to the kitchen and dining room was going to make for interesting responses, but boy I had NO idea it was THIS bad!

Yesterday, I was taking measurments using the V-aux in on the front of my Yamaha rx-v750. I didn't like the results I was getting, and it was a lot of work to check out different speakers, so, today I picked up an RCA splitter so that I can use the Multi-chan input on the back of the receiver.

This definitly improved my results (it took the DSP out of the equation) and it allowed me to send signals directly to the speakers I want to receive them. This means I got a direct signal into the SUB instead of having the receiver's crossover decide what to send to the sub.

While the sub's response doesn't look too bad, there is a HUGE hump in the 25-65 hertz range with a spike just below 40 and just above 50. What's more suprising (although I've always been able to hear it) is that the left, center, and right's spl drops rapidly after around 5k.

A little about my setup. I have a Soundblaster Live! Value sound card (I'm thinking about getting a newer one), and I'm using a Behringer mic plugged into an 802 mixer. I had the mic and mixer from building speakers.

The good news, is that the response from the speakers are repeatable, so that means I finally have the mixer and soundcard setup correctly. I also found out that my sub blends in quite well with the entire front stage. I think if I could smooth out the spikes, then I can bump up the gain on the sub, which would remove the very minor lull that occurs where it blends in with the frontstage.

Anyways. I'll get a few more posts under my belt, then I'll post the graph for the sub and one of the speakers in the frontstage (so ya'll can see the roll-off on the high end).

[Wayne A. Pflughaupt]

Hi David,

I’ve upgraded your status, so you can post pictures now.

Those irregular rooms are usually not nearly as bad as the symmetrical ones. Maybe a different location would do it for you. More oft than not, a corner gets the best response – at least what I’ve seen from my own experience and from others who’ve posted graphs.

Regards,
Wayne

Thanks. Here's a graph of the sub.

As you can see... my 12" 150w Sony doesn't go as far down as I thought it did. Eh, oh well.

I'll try and get a pic of the layout of the room and what's where tomorrow. If any one wants to see any of the other graphs I have... I did measurements of the following:

Sub
Left
Right
Center
Left & sub
Right & Sub
Center & sub


Anyone have any recommendations? Will a BFD show a large improvement (setting up filters in the software show it should)

[Wayne A. Pflughaupt]

Sure, the BFD can help. Flattening response along the 72-dB line would make a world a difference.

It’s your sub that I’m worried about, though. Any equalization places additional headroom demands on a sub. I’m not sure a 150-watt sub has any to spare.

Regards,
Wayne

Wayne A. Pflughaupt wrote:

Sure, the BFD can help. Flattening response along the 72-dB line would make a world a difference.

It’s your sub that I’m worried about, though. Any equalization places additional headroom demands on a sub. I’m not sure a 150-watt sub has any to spare.

Regards,
Wayne

I agree, but with the size of my current room, the sub's gain isn't even at half, so there's still some headroom there.

Plus, even if I get a new sub, I should be able to use the BFD to fix any issue that happens with it.

Here's some more pics:

One is a layout of my living room. I didn't include pics for center, left, and right, but they are located around the TV.

The other two pics are of the left speaker w/ and without the sub.

Any ideas what may be causing the highs to be sucked out? Am I simply off axis on the speakers? I'm at work, but I'll try adjusting the speakers some this evening. I may just be sitting to close to them for a really good response (I'm about 6 ft away from the tv).

Oh, I did notice this morning that all of my graphs are without a soundcard calibration file. I'll do a calibration on the soundcard this evening and see if that makes a huge difference in any of this.

Thanks for looking.

[Wayne A. Pflughaupt]

What kind of speakers are they?

It’s not unusual for speakers to show a high-end droop in response when it’s measured at the listening position. Speaker manufacturers typically get their published specs at a distance of 3 ft. Aside from that, some speakers are just brighter than others. For instance, the SVS SBS-01’s I’m currently evaluating are significantly brighter than my regular speakers.

Re your graphs, it looks like you’re running your mains full-range. That will make it impossible to equalize the sub. Or rather, any equalizing you do to the sub will be negated by the unequalized lows your mains will be generating.

Regards,
Wayne

[brucek]

Oh, I did notice this morning that all of my graphs are without a soundcard calibration file.

The response isn't meaningful until you have a calibration file loaded for both the soundcard and microphone. It can make a huge difference.

brucek

Wayne A. Pflughaupt wrote:

What kind of speakers are they?

It’s not unusual for speakers to show a high-end droop in response when it’s measured at the listening position. Speaker manufacturers typically get their published specs at a distance of 3 ft. Aside from that, some speakers are just brighter than others. For instance, the SVS SBS-01’s I’m currently evaluating are significantly brighter than my regular speakers.

Re your graphs, it looks like you’re running your mains full-range. That will make it impossible to equalize the sub. Or rather, any equalizing you do to the sub will be negated by the unequalized lows your mains will be generating.

Regards,
Wayne

The speakers were the last pair designed by an audio engineer while he was working for a speaker design company. They don't have a brand or model number. They're an older 3-way loudspeaker design. I can get a pic.

I don't actually run the mains full-range, I have them set to small, but I think I changed the LFE to be sent to "both" at one time. I'll check and make sure this was set back to "sub only". I am using the Multi-chan input on the back of the receiver for testing, but I don't remember what all this bypasses in the DSP of the receiver, so I'm not sure if the receiver uses any of the crossovers and eq's built-in to it. It's a RX-V750 if any one knows off the top of their head... I have the manual, so I'll see what I can find.

[brucek]

This means I got a direct signal into the SUB instead of having the receiver's crossover decide what to send to the sub..

Which is exactly opposite to what you want when checking a sub. You want the receivers crossover in place so you can get a realistic view of how the sub will act in the room in normal use..

brucek

Sorry for the confusion guys, my information was incorrect. My receiver DOES still use the crossovers when using the Multi-chan input, but it DOES bypass the DSP.

I also read where if LFE is set to both, then the bass will be sent to both the fronts and the sub even if the fronts are set to Small. I think this is why my left speaker has a response below the crossover.

I'll play with the system more tonight, and post better graphs then.

I hope it's okay that I'm documenting all of this in this post. Maybe it'll help other noobs with their systems.

Much more playing around tonight.

Below are two graphs:

1) purple: Sub in origional location
blue: Sub in new location

2) blue: Sub & right in origional location
purple: Sub & right in New location

I went back to using the V-aux input so that it is going through the crossover. I even played with adjusting the crossover point, and I ended up back at 120hz crossover.

I also set it so that LFE is only going to the sub... it was set to both... that explained some of it.