[TJHUB]

To provide a little background, I have known about and dealt with this bass peak for years now.  In the past, I have EQ'd the peak out by integrating a subwoofer.  My previous setup was an SVS PB13-Ultra EQ'd with BFD (1124P) and currently I have a Seaton Sound SubMersive HP EQ'd with a Velodyne SMS-1.  The problem is that as my setup has evolved sonically, I'm finding I can't live with the subwoofer in my music chain for two reasons.  One is that the bass from the sub is not as articulate as the bass from my main speakers, and it seems that ANYTHING I use as a high-pass filter on my mains degrades the sound quality. 

I do not want explore any other avenues other than what I can possibly do to treat my room (reasonably as it is my living room).  I've been messing around with all of this for far too long now.  I'd love to find a solution that would allow me to just use my main speakers full range for music.  That's it, nothing more. 

So here is a graph of my problem:



If we can argue that I did a fairly good job at placing the overall frequency response at 75db, then we can say I have a bass peak of about 17db at 36Hz.  I'd like to cut this down as much as possible. 

This bass peak doesn't sound all too bad because at these frequencies it's not obnoxious to the music.  However, you can easily hear it in many tracks and I'd like to do something about it.  I'm not a rap music fan, but it is fun to play because my main speakers can really pump out some impressive floor shaking bass.  It's really surprising actually. 

This morning I downloaded a 36Hz test tone and played it while walking around my room with my db meter.  What I found is that if I set the volume level to read 90db at my listening position, the readings were 92db along my front wall from the left of my left speaker (corner by my windows) all the way to about 4' to the right of my right speaker.  The readings did not increase as I got into the corner of the room.  The right side of the room is more open to my foyer where the readings dropped off significantly.  The readings were way low in the middle of the room as expected.  The readings were about 90db all along the wall behind my listening position as well.  They were fairly consistent too, but the corner read about 92db. 

Here is a pic of my room to get an idea of what I'm talking about:



There are more pics of my room in my gallery if needed.

It took me a long time to place my speakers for imaging and depth.  I will not move them.  But please know that moving them in the past didn't really show much change at all in the bass frequencies.  My listening position is also pretty fixed as well.  So whatever I do has to be something other than moving the speakers or listening position. 

I treated my room many months ago with the panels you can see in my gallery.  They are all 4" thick and did VERY little to change any measurements, but the sound of the room changed for the better. 

I don't know if I'm doing any of this the right way or not.  I don't really understand room acoustics very well at all.  I've also put up about as many acoustic panels as I want to, but I'm open to ideas.  However, it is my understanding that acoustic panels are not going to touch the low frequencies I'm dealing with.  I've looked very seriously into making a custom Helmholtz resonator tuned to 36Hz.  What scares me is getting it (or them) properly tuned, and more importantly, placed. 

If I try the Helmholtz resonator solution, would I put them near the speakers or behind my listening position?  Or both?  I need some help trying to figure this all out.  I am so close to having what I consider to be nearly perfect sound. 

Thoughts?

 

 

[BPT]

Show us a graph of just the full range speakers (no subs).
Chris H.

[TJHUB]

That graph is without a sub.  My graphs with the sub look fantastic, they just don't sound that way...

[AB]

What's the floor, suspended or slab?

Have you tried isolating the sub with something like an Auralex Subdude?

[stew]

I had similarly bad, high dB peaks in the low bass region in my room.  I do not have the options of moving my listening position or speaker positions either. I installed two bass traps (GIK), and they seemed to overall improve sound quality, but did not significantly cure the low bass issues.

My solution has been TacT. What a godsend! It has taken me about 9 months to really dial in the sound to my liking. My strategy has been to use it to reign in the bass problems, while leaving frequencies above about 250Hz untouched. But now that it's fairly finalized - wow! One audio buddy remarked that, with the TacT, my system is finally living up to its potential. Another non-audiophile friend (but, she is a Grammy winning songwriter, so you can say she has an ear for music) remarked that, with TacT, the music sounds like it's been remastered and is much clearer overall.

[stew]

Ps - I have a post on my audio blog about the TacT curves I am using, with some more detailed comments on the sound quality:

www.theaudiogardensf.blogspot.com

[roscoeiii]

Since it looks like your source is digital, you could also use a software solution to correct for the peak. On a Mac, Pure Music has a parametric EQ (or at least a parametric EQ pug-in is an option). Not sure how to do it on PC, or how your use of a Squeezebox Touch would affect your ability to do this.

[rajacat]

How about adding three or more Rythmik servo subs to equalize the response throughout the room?
http://www.rythmikaudio.com/products.html

-Roy

[HAL]

It looks like you are using REW for the measurements.  Do you have calibration data for the mic?  The RS meter has known response deviations from flat below 50Hz. 

Just thinking that it might be partly mic response related.

[TJHUB]

What's the floor, suspended or slab?

Have you tried isolating the sub with something like an Auralex Subdude?

The floor is suspended, but I don't think that's the issue.  Besides, it's the issue of any sort of high-pass filter on my mains I'm not liking either. 

I had similarly bad, high dB peaks in the low bass region in my room.  I do not have the options of moving my listening position or speaker positions either. I installed two bass traps (GIK), and they seemed to overall improve sound quality, but did not significantly cure the low bass issues.

My solution has been TacT. What a godsend! It has taken me about 9 months to really dial in the sound to my liking. My strategy has been to use it to reign in the bass problems, while leaving frequencies above about 250Hz untouched. But now that it's fairly finalized - wow! One audio buddy remarked that, with the TacT, my system is finally living up to its potential. Another non-audiophile friend (but, she is a Grammy winning songwriter, so you can say she has an ear for music) remarked that, with TacT, the music sounds like it's been remastered and is much clearer overall.

Thanks for the information.  I'd like to try a TacT setup, but it's a bit pricey for me at the moment.  I was hoping for a less expensive solution...

Since it looks like your source is digital, you could also use a software solution to correct for the peak. On a Mac, Pure Music has a parametric EQ (or at least a parametric EQ pug-in is an option). Not sure how to do it on PC, or how your use of a Squeezebox Touch would affect your ability to do this.

My source is digital; a Squeezebox Duet.  I tried the EQ plugin for Squeezebox Server today, but it doesn't work for me.  I have no idea what is wrong.  It functions, but it doesn't change the sound at all.  Too bad as I was hopeful it would work. 

How about adding three or more Rythmik servo subs to equalize the response throughout the room?
http://www.rythmikaudio.com/products.html

-Roy

I've strongly considered selling my Submersive and going with a pair of Rythmik F15HPs, but again, the problem doesn't just lie with the sub.  My issue is also putting any sort of high-pass filter on my main speakers.  It just seems to affect the sound in too much of a negative way.  I'd rather just stay away from the sub idea for 2-channel and I'll just use the sub for HT.

It looks like you are using REW for the measurements.  Do you have calibration data for the mic?  The RS meter has known response deviations from flat below 50Hz. 

Just thinking that it might be partly mic response related.

I am using REW, but I use an ECM8000 mic with the calibration file.  I am positive this is not a measuring problem.  I can clearly hear the issue.  It's real.  I'm not saying the measurements are perfect, but it sounds like it measures.  It's just that a lot of music isn't affected by the peak all that much.  Unfortunately there are many tracks where the peak is VERY audible.

[stew]

The TacT is expensive new.  Try audiogon.  I found mine for around $1000.

Good luck solving that bass issue!

[tonyptony]

My source is digital; a Squeezebox Duet.  I tried the EQ plugin for Squeezebox Server today, but it doesn't work for me.  I have no idea what is wrong.  It functions, but it doesn't change the sound at all.  Too bad as I was hopeful it would work. 

TJ, I use a Duet and a Touch and the Inguz plugin works at least through version 7.5.1 of the SB Server software. There is a bunch of information in the SB forums Audiophile section that details how to get this to work with the newer Server software. Yes, Inguz hasn't been updated in quite a while (more's the pity) but it can be set up to work.

[BobRex]

TJ, you say you have not had good luck with hi-pass filters.  What filters have you tried?

[TJHUB]

TJ, you say you have not had good luck with hi-pass filters.  What filters have you tried?

Not many really.  I tried the HP of my Velodyne SMS-1 and a pair of FMOD RCA filters.  The FMODs are much better than the SMS, but after recently pulling out the FMODs, they aren't all that great either.  I was planning to try a passive from Marchand, but I've read posts from people that say while it is better than anything else they've tried, it too dulls the sound a bit.  I'd hate to spend money to gain nothing here.

[Rocket_Ronny]

Simple problem to solve. Just pull down the 32 hz e.q. in the equalizer. That is if you were using I-tunes.

Although this does not solve your problem it does make a strong case for computer audio and having available a e.q. to fix problems like this.


Rocket_Ronny

[AK]

Why not run speakers full range and multiple subs. I think it was first suggested by Geddes. I've read only positive reviews of such setup. I have four subs myself.

[poseidonsvoice]

Why not run speakers full range and multiple subs. I think it was first suggested by Geddes. I've read only positive reviews of such setup. I have four subs myself.

Read what he stated in his original post:

I'd love to find a solution that would allow me to just use my main speakers full range for music.  That's it, nothing more.

If you are going to only stick with your ONE listening position, then I see EQ as your possible way out. You need to find a unit that is sonically non-intrusive however. The TACT units come highly recommended. If anybody has one here on this forum, they could help the poor fella out with a 1 week trial. My colleagues and I tend to do stuff like this often as we trust each other.

Anand.

P.S. No I don't own a TACT.

[tonyptony]

TJ, I encourage you to check out the info on the squeezebox forums in getting Inguz to work in version 7.5.1 of the Server. It works well and you'll be able to easily adjust this peak. On top of that, once you get used to it you'll be able to use its DSP functions to its fullest.

This thread deal with a number of issues for the recent SB Server utilization

http://forums.slimdevices.com/showthread.php?t=77084

[TJHUB]

TJ, I encourage you to check out the info on the squeezebox forums in getting Inguz to work in version 7.5.1 of the Server. It works well and you'll be able to easily adjust this peak. On top of that, once you get used to it you'll be able to use its DSP functions to its fullest.

This thread deal with a number of issues for the recent SB Server utilization

http://forums.slimdevices.com/showthread.php?t=77084

I actually figured out what the problem was.  I downloaded a 36Hz test tone to do my measuring around the room and I was using that test tone on my Duet to measure the change with the Inguz EQ changes.  The test tone is an MP3!  I did not know that the Inguz EQ plugin only worked for FLAC.  I made some adjustments last night with the EQ and playing my FLAC music shows the EQ is working fine. 

I don't yet know if this is my potential solution as I need a little listening time to figure out is the plugin is audible to me or not in a negative way.  This would be a perfect solution for me if this works.  Not to mention that it's free and required very little effort on my part.

[poseidonsvoice]

I actually figured out what the problem was.  I downloaded a 36Hz test tone to do my measuring around the room and I was using that test tone on my Duet to measure the change with the Inguz EQ changes.  The test tone is an MP3!  I did not know that the Inguz EQ plugin only worked for FLAC.  I made some adjustments last night with the EQ and playing my FLAC music shows the EQ is working fine. 

I don't yet know if this is my potential solution as I need a little listening time to figure out is the plugin is audible to me or not in a negative way.  This would be a perfect solution for me if this works.  Not to mention that it's free and required very little effort on my part.

Show us the REW measurements again to see if this plugin works, we'll let you know! Best of luck! 

Anand