Dual Subs & Soundstage

[Ampdog]

Looking in carefully - but I still miss the point. As was said before: Subs do not image. So respecting all that was said regarding how to connect the subs, equalise the lot, etc. Assuming that the concept of imaging as in 'soundstage' and 'positioning of instruments' is agreed upon, I simply cannot see how frequencies below say 150 Hz can have an effect on the topic. One can come up with umpteen different suggestions, still. One of mine would be to disconnect both subs, estimate/determine the soundstage, and then connect one sub at a time: How much of a difference, if at all? Momentarily placing the subs next to each other (can't recall whether this has been suggested), is a different 'lack of soundstage' observed - etc.?

I would dearly like to read the final solution to all this myself!

 

[walter duque]

What about the slope settings? I have my high pass set to 12 db and low pass at 24 db. Anything lower then 24 you might be getting mid range in there what could mess with your sound stage. Set everything to factory default and start all over. Just a thought...

 

[Muzykant]

Thank you. I have made some adjustments since my last post. I will give details probably later today.

 

[Muzykant]

These are the changes I made:

I connected both RCA inputs of sub #1 to Emotiva unit using a splitter, and then connected the 2 subs together via the first sub's outputs with 2 more RCA cables. This increased the volume substantially.

I measured the distances for each speaker and sub and set them correctly on my Emotiva unit. This seemed to help somewhat with the clarity issue.

I bought an SPL meter at Guitar Center (never thought I would ever make that purchase there) and did the best I could setting the levels equally using the Emotiva unit's noise signal. It is not an easy task, as the meter fluctuates constantly within 1 decibel range, sometimes even more. I wouldn't say my house is exactly noisy either. Only the right speakers needed adjustment, but it did make a difference in the overall balance. I was surprised that after equaling the speakers' 75 db reference level, the subs were louder than what I am used to. I had them turned down by up to 6 db for some movies afterwards. I listen at levels where movie dialogue sounds like people are talking in the room, and quieter at night (respecting my neighbors). I can't even imagine what setting the subs to 80 db level (as advised by one Audioholics article) would be like.

I changed the crossover to 80 Hz with a 24 db/octave slope and did not experience the localization issue I had before. I think having 2 subs really helps masking it.

So, the soundstage issue did improve, but didn't completely go away. Although to a lesser degree, I still experience that effect of music sounding like there is a bit of foam in my ears, a sensation that makes you want to turn your head to hear better. I really think phase is to blame. Can I utilize the SPL meter to fix it somehow?

 

[walter duque]

These are the changes I made:

I connected both RCA inputs of sub #1 to Emotiva unit using a splitter, and then connected the 2 subs together via the first sub's outputs with 2 more RCA cables. This increased the volume substantially.

I measured the distances for each speaker and sub and set them correctly on my Emotiva unit. This seemed to help somewhat with the clarity issue.

I bought an SPL meter at Guitar Center (never thought I would ever make that purchase there) and did the best I could setting the levels equally using the Emotiva unit's noise signal. It is not an easy task, as the meter fluctuates constantly within 1 decibel range, sometimes even more. I wouldn't say my house is exactly noisy either. Only the right speakers needed adjustment, but it did make a difference in the overall balance. I was surprised that after equaling the speakers' 75 db reference level, the subs were louder than what I am used to. I had them turned down by up to 6 db for some movies afterwards. I listen at levels where movie dialogue sounds like people are talking in the room, and quieter at night (respecting my neighbors). I can't even imagine what setting the subs to 80 db level (as advised by one Audioholics article) would be like.

I changed the crossover to 80 Hz with a 24 db/octave slope and did not experience the localization issue I had before. I think having 2 subs really helps masking it.

So, the soundstage issue did improve, but didn't completely go away. Although to a lesser degree, I still experience that effect of music sounding like there is a bit of foam in my ears, a sensation that makes you want to turn your head to hear better. I really think phase is to blame. Can I utilize the SPL meter to fix it somehow?

Seems to me everything is working, so there are no repairs and other expenses involved. Just keep fine tuning your system and that's all you need.

 

[ousooner2]

A picture of the room, speaker locations in that room and room dimensions would help

 

[Muzykant]

I would like to thank all that answered in this thread. I believe I have now fixed the problem by rearranging my speaker and sitting positions. It now sounds good enough to my ears (well, maybe still slightly less than ideal, but passable).

I have a quick question. I keep reading about subwoofers shaking up rooms and rattling windows, the tactile feel and all... How loud should I watch movies to experience this? As of now, I watch at levels where the dialogue sounds like talking in real life, with subwoofers registering the same sound pressure on the SPL meter playing test tones as the other speakers. With this level I have never felt any vibrations sitting on my couch. I can hear the bass fine down to the low 20s, but it is not resonating through the furniture.

Raising the sub level by 5 db or so results in unnaturally hot bass while raising the volume makes the dialogue too loud. Which way should I go to feel the sound effects?

 

[ImcLoud]

raise the volume control on the subs themselves or the subs trim in your avr...

I think you have a serious setup problem, them subs should be rattling your teeth... Take some pics or draw a picture of how this is wired and setup, something is seriously wrong, I NEVER heard of adding a sub making the system worse, it always smooths room responce and makes everything nicer, subs arent working as hard, less likely to locate them, ect...

 

[walter duque]

I would like to thank all that answered in this thread. I believe I have now fixed the problem by rearranging my speaker and sitting positions. It now sounds good enough to my ears (well, maybe still slightly less than ideal, but passable).

I have a quick question. I keep reading about subwoofers shaking up rooms and rattling windows, the tactile feel and all... How loud should I watch movies to experience this? As of now, I watch at levels where the dialogue sounds like talking in real life, with subwoofers registering the same sound pressure on the SPL meter playing test tones as the other speakers. With this level I have never felt any vibrations sitting on my couch. I can hear the bass fine down to the low 20s, but it is not resonating through the furniture.

Raising the sub level by 5 db or so results in unnaturally hot bass while raising the volume makes the dialogue too loud. Which way should I go to feel the sound effects?

Rattling windows good subs shouldn't do, cheap subs yes. But you should feel the structure of you house move (it's like wow I think this floor just moved). I think I feel my subs more than I hear them, they're the extension of the towers, they really don't sound like subs at all. Makes any sense, most likely not.

 

[Muzykant]

Hmm... So it looks like my listening volume is fine, but my subs should have more output. I have their gain set to -12 db with preamp volume set to 0. I mean, I could set the gain control to 0 and have way more output, but somehow this way movies become unnaturally bass-heavy. I am talking about the relative balance between different frequencies.

What frequencies produce that feeling of moving structure?

Also, another question. Playing the internal test tones I hit 75 db with each speaker (and a pair of subs) at my listening position when my volume is set to 40. How does that relate to the reference level?

 

[Drunder40]

Rattling windows good subs shouldn't do, cheap subs yes. But you should feel the structure of you house move (it's like wow I think this floor just moved). I think I feel my subs more than I hear them, they're the extension of the towers, they really don't sound like subs at all. Makes any sense, most likely not.

Just curious, why does a good sub not rattle windows where a cheap sub does..

 

[herbu]

I keep reading about subwoofers shaking up rooms and rattling windows, the tactile feel and all... How loud should I watch movies to experience this? As of now, I watch at levels where the dialogue sounds like talking in real life

I think your overall volume is too low to shake the room. When lightning strikes near enough for the thunder to shake the room, is the thunder volume like talking in real life? No... it's LOUD... completely eclipsing normal conversation. The volume in a theater is louder than normal conversation. I think to get the gut punching, room shaking you want, you just need to crank it up.

 

[Muzykant]

Thank you for your reply. I haven't been to a movie theater for a long time, but I now remember that it usually is quite loud in there.

I read a little bit about that floor/couch shaking sensation when watching bass-heavy movies, and it looks like it's usually associated with ultra-low frequencies (around 20 Hz and lower). My guess is that my subs do not go that low with the same intensity as they play in the 30 Hz and up register. Below 30 Hz they start rolling off quite rapidly and really run out of steam just below 20. So while mid and low bass sounds very loud to me, the ultra low frequencies are relatively much quieter and lack the impact necessary to shake things up. Probably should have gone with ported Ultras to get that effect.

 

[jcparks]

Hey Muzykant... this has been quite the post and I didn't read all of it so I apologize if this is a re-post. Anyway I just got a new sub myself and while trying to figure out an easy way to adjust the phase I stumbled on to this article..
Setting Subwoofer Phase the Easy Way | Sound & Vision
With dual subs I guess you could just do this for one sub at a time... I dunno? I am still learning myself .

 

[Muzykant]

Thanks, jcparks!

 

[walter duque]

Just curious, why does a good sub not rattle windows where a cheap sub does..

You can make just about any sub rattle windows (if you're living in a shack). I happen to associate that with the sub not being controlled. Most subs (that is by popular demand) aren't even in step with the rest of the band and they still play when the song is over. The average consumer doesn't even know what a good sub sounds like. They hear a fart box in the corner and they think that's great, wow what a sub, can you hear that thing?

 

[ImcLoud]

can we have some pictures of how these are setup and the room they are in??? I think if you do that someone is going to "ahh haa" you. and give you the answer to your problem, dancing around this is not going to get it fixed, this thread is going to cause a couple members to disagree and argue after a while, and then it will be locked and we will never know what was wrong with your system, PICTURES PLEASE.... of subs, room, and wiring if possible.. thank you...

 

[Muzykant]

ImcLoud, I totally understand your point and agree. The thing is, I am embarrassed to show my room, as its first temporary setup became permanent for now. I, for example, have no speaker stands, so I used whatever furniture I had. Same with the TV and components. See, the recent move ate a lot of money, so some things had to wait a bit... and still waiting.

 

[jcparks]

I dont think you've anything to be self conscience about sir, nobody is here to judge, and I have seen what I would consider to be some interesting rooms on this thread... lets just say if these guys aren't bachelors, then they have an amazing spouse. I saw one thread that had speakers set up on TV trays. I personally am using a makeshift Buffet as a TV stand with speakers on the fold out extensions. Only you can decide what you are comfortable with, but speaking from experience... There is a great set of people here on these forums.
Also if you are artistic you may consider drawing out a diagram outlining your situation.

 

[ImcLoud]

ImcLoud, I totally understand your point and agree. The thing is, I am embarrassed to show my room, as its first temporary setup became permanent for now. I, for example, have no speaker stands, so I used whatever furniture I had. Same with the TV and components. See, the recent move ate a lot of money, so some things had to wait a bit... and still waiting.

Now you have to put up a pic or people are going to think you don't have the system at all, lol...
Don't be embarrassed, it is an internet forum, I am sitting in boxer shorts with 2 different socks on eating fruity pebbles on my couch watching a family guy episode from when stewey used to carry a phaser gun {9:34 pm here}, if you wanted a pic I would snap one, lol.... Throw a pic up here and we will find the issue, No one will judge you, I almost promise it... It just doesn't make sense, adding a second sub always IME smooths room response and makes the sub/main transition smoother...

We didn't judge #$@**$& when he posted this pic of his office, if I remember rite he got some nice compliments on the super hero curtains..