Axiom Home Page Forums General Discussion Advice from Axiom Owners Do I have my speakers setup right?

Ok, I know there are so many variables in this hobby that can make or break a good sound result, however, something is bugging me.

The other night I was over at a friends house watching movies. He has regular Pioneer 5.1 AVR that is probably 2-3 years old. For speakers he has some NHT Bookshelves for the mains, a NHT Center, and some cough cough choke BOSE white speakers in the back for surround. His sub is a Velodyne, but not a top of the line model and is a few years old, I think it has a 10" woofer. His room is fairly small, about 12' x 12'.

Anyway, I spent some time calibrating all his speakers using my SPL meter. His AVR only went down to 100 for a crossover, so we used that setting.

Ok, for the question....as you all know many movies have the 20th Century Intro before the movie starts. I was amazed on how it sounded once we calibrated his speakers. What really amazed me was the lowwww bass drum thump throughout the trailer, and at the very end. It sounded so Tight and just rocked the room.

So last night I'm thinking man my setup will sound better. Actually, the drum thump was hardly heard at all. I could hear it, but it did not set me back in my chair and say WoW? I tried bumping up the dB's on the sub channel which helped a little. I've got everything set to Small and crossed at 80hz on the AVR. I would think my m60's and EP500 would have put his system to shame on the same intro, I have to say his sounded better. I even tried Large on the mains and LFE+Main for the sub option.

What is the problem, is it my room is so much larger, is it my speaker placement, do I need to map out using realtraps to find holes? I'm using my HTPC with SPDIF out to my Denon 2805 so it does all the decoding. I could turn up the sub gain but then that would go against my SPL calibration using the meter.

I don't know this really bugs me for some reason, that bass drum should really thump on my setup I would think better than it does on his system. Any thoughts?

Randy

Randy, it may just be the room. Your friend has a very small square room which may be exciting certain low frequencies (maybe giving that intro scene a boost). I have a room almost that same size, and right now I'm trying to place some subs. Unfortunately where I sit, I get a huge suck out in bass, if I take three steps to the right (near the corner), boom, instant bass.

It doesn't take much to pressurize small rooms. Used to have a VTF 3 in a 10x10 room. Sometimes it felt like the walls were flexing.

I think you better get the 80's, seriously though it could just be your sub placement, my final placement of my sub was in the corner of the room, it gave me a much better bass response than when I had it placed more in the open.

Don't you have a huge room, Randy?

Just by more subs.

I think you ned to get another sub to fill that room. oh.....the 600 comes to mind.

Before you go buying another sub -- and I'm not saying you don't need one -- try repositioning your sub. Your sweet spot might just be in a null zone.

Alright, example.

I think I have posted pictures of my dorm room. If you remember it had a loft (3 beds in a wooden frame 4 feet high across the entire room). Anyways, I was sitting under the loft with my axioms. We just took it down, and my axioms sound entirely different. More open, I think. The room is long, 20 feet. And now that the couch is out of here and the beds are on the ground, the room is really reflective, so sometimes I think it sounds like the music is getting out of control because of all the late reflections I'm hearing.

My room at home is 12x12. I'm moving back in 3 days, and my axioms sounded the best there. Bass was huge and they sounded very nice.

Something about the quick reflections of a room are nice in some speaker setups. To simulate these quick reflections, you could probably invest in some wall treatements as reflecting points. I bet that would help "bring in the walls" of your room quite a bit.

Good luck!

I had a similar experience with my sub. I had it on the right side of the room, nearish the corner. It was ok. Then I moved it in order to get the Xmas tree in, and put it in the left front corner of the room, much closer to the wall. BAM! Much better bass.

Rooms suck.

Someday, I'm gonna live in the country and when I do I'm gonna bring my Axioms outside to hear them room-less.

Maybe Axiom will offer a moss stained finish by then.

Guess, I'll have to try the crawl method.... I put the sub in the corner furthest from the open room per a lot of your requests....I guess I could always turn the gain up to 12 o'clock and sit back like the Maxell guy.

I did the crawl method once at Dennis'...without the crawl. Those tile floors, although beautiful to look at, don't do justice on pointy knees. The crawl became more of a squatting motion. I'd walk around the room to a few certain areas and slowly get down in formation to hear the changes taking place.

I did the sub crawl about a month ago with outstanding results. If you haven't done it yet, you should certainly give it a try.

i did the sub crawl as well but the spikes kept digging into my back.

So if I do the sub crawl, I assume I would remove the middle chair from the front row, and place the sub there, facing the screen? Then crawl around like a monkey listening for the best sound? What type of music/sounds do you play, I assume something with lots of LFE?

Actually, you'd put the sub on the chair, which would more closely approximate the position of your head in the chair. Because good bass can be like football -- a game of inches -- you want to be as precise as possible.

The whole idea with the sub crawl is that once you find the spot where the bass sounds best, you simply reverse the position of the sub and your head.

I guess my only question is that I don't always sit in the same chair. For 2.35 movies, I like to sit in the back row so my eyes don't have to dart back and forth so much like when your in the IMAX. For smaller ratio movies I sometimes sit in the front row if we don't have to many guests. I wonder if I place it in the middle of the couch, which would be an average of all positions. If I did this would the middle front row chair get in the way of the testing, maybe I'd move it out of the way then?

Randy

In reply to:

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you simply reverse the position of the sub and your head.

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So the sub goes up my *ss?

THAT explains the bass problems I've had in my room and why I can't feel the bass!

Give Mark an award or something. You know, like the daily "Thanks for making me spit coffee on my computer Commendation".

LOL!

Actually it was a Mountain Dew on my HP laptop keyboard at work, hmmm, time to upgrade, ha ha

So anybody want to comment on my last "on topic" question above.

bass waves are long enough that they don't get blocked by furniture in the same way the higher frequencies would. Also remember that it will be pretty hard to get good bass in every seat without multiple subs. This is a best effort sort of thing. You may eventually need to settle -- or throw lots of money at it.

Dear Mr. On-Topic,

I agree with Peter.

I would also think that - if the positioning of the seating DID actually make a difference, you would want to leave it configured in the way you usually have it for viewing.

I don't think you are going to be able to get uniform bass response at all the listening positions because some of them are so much closer to walls than others. I'd think you would have to do multiple sub crawls (as many as you can handle, I guess) - marking various sub positions and then moving the sub to the next listening location.

I'd be tempted to use a 20-80Hz sweep or something like that.

In addition to Peter's astute observation about throwing money at the problem, I just don't see any way to figure this out without you spending an extended amount of time on your knees.

I suppose I better go get some knee pads.

LOL!!

What a sense of humor!!!

So...I've watching this thread since it started... Have you done the crawl yet??

No I'm thinking tomorrow I may have some time. I have some buddies coming over to watch the NASCAR race in HD on my big screen and crank it up with the axioms. I still am trying to figure out where to put the sub, based on my above follow questions...

So have you done the crawl yet ? If so, what were your results ?

If truly is amazing. People with cheaper setups can have awesome sound. I love my current system. However, my friends system has more punchy base from the sub while mine exhibits more rumble. I like punch. So I am a little envious. It has a lot to do with placement and room acoustics. I have not spent the time to go over the placement of my mains and sub. It's all about compromise. And the optimal position for those speakers might not be physically feasible.

A ton of acoustics is the room. You can have a super high end sound system sound like utter crap if everything isn't setup right, or that certain room has bad accoustics.

I've moved my axioms around a bit from room to room, college and back, and couple places in my house. Definately a big difference.

Ok, I did the crawl recently. I will tell you, at first I kept moving around and thought I really don't hear a lot of difference no matter where I go? I tried variouos CD's with low bass. I even put in a cd mix I created that had nothing but BOSS Bass tracks. I even turned off the mains, just so I heard the sub only. Anyway, I think I did find a better home for the sub. Months ago, many of you recommended that I put the sub near the left corner, which would be the furthest cornere away from the opening into the larger room (see above pictures). Well, I ended up centering the sub below the screen, raised my center channel up onto the wall so it is more inline with my m60 tweeters. It actually looks pretty cool having my EP500 below the VP150, there is about 6" between the two.

Anyway, I think the bass is much better/tighter/explosive/less boomy...

I think I may rerun the RealTraps experiment again and post a new graph on my other RealTraps post. Bridgman is evaluating my results.