fixed sub and seating location -> bass sucks

[mike c]

ok, I did a little arranging ... now everywhere but where I sit has good strong bass (i.e. corners of the room, just in front of the tv, standing up)

by ear, they seem to be dips.
oh, I already tried using just 1 sub (both of them in their own)

anyway, what to do if the sub and seating locations are fixed?
will room treatment help? what kind? (am only interested in treatment that will help improve bass)

I will get an area rug, but the couches that I ordered are leather.
one of this: http://www.lazboy.com/ourfurniture/product.aspx?pid=94,
and two of this: http://www.lazboy.com/ourfurniture/product.aspx?pid=2032,

 

[Ethan Winer]

Mike,

> everywhere but where I sit has good strong bass <

Yeah, this is very common.

> by ear, they seem to be dips. <

What usually happens is a series of many peaks and deep nulls throughout the entire bass range. But as you observed, the nulls are often the biggest offender.

> will room treatment help? <

Not only will that help, it's the only reasonable solution.

> what kind? <

What you need is bass traps that are effective to as low a frequency as possible. It's impossible to make any room perfectly flat, but the more bass traps you have, the flatter and tighter the low end will be. It's really that simple.

--Ethan

 

[Johnd]

Particularly with not one soft surface (other than the seat cushion) shown in the room.

 

[mike c]

johnd, and to think I cursed the room carpet I had before

ethan, so for realtraps products, which one has the lowest frequency effectivity? minitraps? nothing narrower?

 

[Johnd]

Mike: just out of curiosity, did you keep all the same equipment but change room environments? And, if so, is your only complaint the lack of flatness with bass (the room isn't overly bright, reflective, etc)? Even though I noted you're adding a padded couch and carpet...I'm just curious. Cheers.

 

[mike c]

nope, totally different setup. it WAS the same room, but I renovated it in time for my marriage this year.

my previous sub was a JBL HTIB sub (10" 150w) it didn't have any kick in the chest or pant flapping powers. but after I removed my carpet, even my PC altec lansing sub can boom the room. (boomy of course)

 

[mtrycrafts]

ok, I did a little arranging ... now everywhere but where I sit has good strong bass (i.e. corners of the room, just in front of the tv, standing up)

by ear, they seem to be dips.
oh, I already tried using just 1 sub (both of them in their own)

anyway, what to do if the sub and seating locations are fixed?
will room treatment help? what kind? (am only interested in treatment that will help improve bass)
,

The very first thing I would do is plot the frequency response at exactly where you sit, since you have no options left. Check each sub by itself, write it down, then both together and see what you have.
http://snapbug.tripod.com/
This has instructions how to and a link to a Word document, free, to plot it. You can use the second chart where it has corrected response for the second sub so you can see. The third chart would be both subs running. It also accounts for the Radio Shack FR inaccuracies.

You need a CD with low frequency sine waves to excite the room modes, from 10 Hz to at least the crossover frequency, hopefully in 1 cycle increments. Need an RS Spl meter, and a stand such as a camera stand to hold the meter.

This will tell you where and how bad the fr stands. Right now, you only know it is bad; that is telling nothing.

I would also recommend that Behringer DSP 1124; in is $100 in th eUS, not sure what it would be there. Maybe that poster from Canada, can ship one as it only costs $100CND It has 12 frequencies you can adjust in each channel.
I doubt room treatment will fix a 20+ dB spl variation and you will be lucky if that is all you have.

 

[jeffsg4mac]

ok, I did a little arranging ... now everywhere but where I sit has good strong bass (i.e. corners of the room, just in front of the tv, standing up)

by ear, they seem to be dips.
oh, I already tried using just 1 sub (both of them in their own.

Mike, if that is where you have your subs positioned then that is more likely one of your problems. Up front is possibly the worst place you could have them. That spot has never worked well for any room I have ever tried.

Since you have 2 subs you really need to place one in back and one in front. preferably both in center but if that won't work then try oposing corners. That is how I have my two and I have good response from every seat in the room. Read all of this article and look at the charts in the back. http://www.audioholics.com/techtips/setup/loudspeakers/SubwooferplacementP1.php

 

[mike c]

mtrycrafts, yup ... that's the first thing i'll do when I complete the checklist: external sound card, SPL meter, BFD
the BFD is available here, about 170+USD
the SPL meter I'll get by the end of the month
the soundcard, I'm looking for an external that's only 50bucks. the ones available are 170USD!
I have the 1/6 octave thingy, an AVIA thingy and the roomEQwizard


jeff, I have piping in the floor just for the sub cable that goes from front to back. but will have to put in the wire (its empty) I will have to wait for the equipment to arrive before I start moving stuff. My back almost gave out moving those ... alone!
when you say opposing corners, do you mean, FRONT LEFT and REAR RIGHT? or FL and RL?

 

[mike c]

in theory, will a bass trap help with a null/dip? I mean sure it will clean up the bass - make it sound nice and tight. but will it really improve nulls?

 

[jeffsg4mac]

when you say opposing corners, do you mean, FRONT LEFT and REAR RIGHT? or FL and RL?

Yes, exactly or fc rc if you can do it. Mine are FL RR

 

[ScottMayo]

If you can move the subs around, there are several configurations that will help - experimenting is good. Corner placement maximizes output - that's not always a good thing, and it might or might not move yours nulls out of your way.

Yes, bass trapping will diminish nulls. Getting your seating off the back wall will help also. Experiment.

 

[Ethan Winer]

Mike,

> for realtraps products, which one has the lowest frequency effectivity? <

Our most powerful bass trap is the MondoTrap. But it's considered bad form for a vendor to discuss his own products in a public forum, so I'd ask you to email me for specific product information. I'm here to help in the most general sense.

> will a bass trap help with a null/dip? <

Yes! Bass traps reduce peaks, raise nulls, and also reduce low frequency ringing. And the improvement affects every location in the room, not just one listening position. There's a huge amount of information on my company's web site about this stuff, including many magazine articles and videos. There's also a "test tone CD" you can download to measure your LF response very accurately.

--Ethan

 

[genesis471]

The very first thing I would do is plot the frequency response at exactly where you sit, since you have no options left. Check each sub by itself, write it down, then both together and see what you have.
http://snapbug.tripod.com/
This has instructions how to and a link to a Word document, free, to plot it. You can use the second chart where it has corrected response for the second sub so you can see. The third chart would be both subs running. It also accounts for the Radio Shack FR inaccuracies.

You need a CD with low frequency sine waves to excite the room modes, from 10 Hz to at least the crossover frequency, hopefully in 1 cycle increments. Need an RS Spl meter, and a stand such as a camera stand to hold the meter.

This will tell you where and how bad the fr stands. Right now, you only know it is bad; that is telling nothing.

I would also recommend that Behringer DSP 1124; in is $100 in th eUS, not sure what it would be there. Maybe that poster from Canada, can ship one as it only costs $100CND It has 12 frequencies you can adjust in each channel.
I doubt room treatment will fix a 20+ dB spl variation and you will be lucky if that is all you have.

Great post! Just picked up the DSP1124. Anyone know where to download the wave sines? I read and printed the article, downloaded the excel spreadsheet... but need the sine waves!

Thanks,

Mike

 

[genesis471]

Got it simply by emailing Sonnie! Thanks a ton Sonnie!

Mike

 

[Sheep]

Bah! Just get an SMS-1.

SheepStar

 

[mike c]

a BFD + Creative Digital LX external soundcard = less than half the sms-1