Subwoofers for muddier bass

D

Devg

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Hi Folks,

I am currently using a pair of AZ Crescendo MkII in a 15'x20'x8' room. The Crescendos are powered with Nords One up monoblock. The problem I have in the room isn't the lack of or boomy bass but the bass is muddier. Most of the time its difficult to hear or differentiate between notes in the bass line and they presents as a one note tone. The same speakers in other places I have listened to works wonderfully and very musical. I have GIK monster bass traps in the corners behind the speakers and tried several different speaker position but without luck. The back of the speakers are about 6' from the back wall.

I have been thinking of getting a pair of REL subwoofers to handle this problem but not sure if it would help in my situation. What are your thoughts on this ?

Appreciate any response and thanks in advance.

-- Dev
 
Dev, once I put too many bass traps in my media room and my bass became one note and very overbearing. Removing two of them cured that issue for my room. Just given as an information point. As a suggestion, perhaps you could remove your current bass traps and measure the room's response and then treat to respond to the measurements.
 
Thanks Steve. I had earlier started with 4 of them (based on GIK's recommendation from the REW measurements I had sent them) and now down to 2. It helped in making the room a bit more lively. I would certainly remove the remaining and re-measure this coming weekend. My impression from reading various forums, especially from Realtraps, is that every room needs a minimum of 8 bass traps to tame the room modes. I can't put those many numbers traps, so was looking for a solution with the subs.
 
If you are using them in the corners behind the speakers have you tried moving them to the corners on the other end? Don't know how you came up with the 6' from the rear positioning but have you tried moving them back to a starting point of 2' from the front baffle and coming forward 6" at a time. I usually start with divisions of the room by odd numbers as recommended by Vandersteen and then an inch at a time. In this room I use fifths and it has worked for every speaker with minor adjustments.
 
Jack,
the 4 traps was in the front corner (behind the speakers) stacked one on top of another. I can't move them to the other corners since these corners are occupied to other stuff - one had a sliding door and other has a cabinet.

I think I have tried most of the speaker placement available - cardas method, Wilson method, Vandersteen method, rule of 1/3rd, rule of 1/5th, and several others which I don't remember. Started with the back against the wall (for bass reinforcement) and quickly realized that it needs to moved forward - a typical problem that usually one faces is the best position for bass is not the position for a great soundstage. The current distance gets me an excellent soundstage and good bass, its just that the bass lacks quality or isn't musical enough and sounds like a one note.

Any other possible experiments could you think of ? The other part I wanted to understand is what causes these kind of problems ? Too much ringing ? If we understand that, then it might be easier to find a solution ?
 
Was the bass trap design before the AZ's, if so they may not be necessary at all with that particular speaker. Like was suggested earlier take them all out and see what you get. When I had TL based Reynauds in this room I didn't use any bass traps, same with the the sealed Vandersteen's. I only had to get bass traps when I went to rear ported speakers to alleviate a 70-80 Hz hump. In the interest of full disclosure all of those earlier set ups included Vandersteen 2WQ's which may have alleviated the problem. When I put the KO's in the room I never could get the 2WQ's to blend with the Nola's so I took them out. Then the obvious hump was hard to avoid. It was then that I had to look for other solutions.
 
Ok, so I removed all the traps and the results are surprising. The sound stage opened up quiet a bit and now I stated to feel the musicality in the bass but its a bit bloated which I guess is expected after removing the bass traps. This weekend I would take some measurements and see what gives. I also think I might need to redo the speaker placement.

Now that I think back, apart for the audio shows, the two personal rooms (one is of Robert's itself) I heard the Crescendos did not have any bass traps either. So may be it was fault on my part and overthinking that every room needs some. Now that I have bloated bass, how do I go about solving this ?

Btw Jack, how did you solve the 70-80 Hz hump ? Its been a long time since I took measurements of my room but as far as I can recollect, I have a deep suck out in 30-40Hz range and few humps in the 80Hz and 120Hz range.
 
Dev - what you are hearing now, is it with your Pass amps or your NORD amps?

30-40hz + 80-120hz is a big range.

Mike
 
Mike said:
Dev - what you are hearing now, is it with your Pass amps or your NORD amps?

30-40hz + 80-120hz is a big range.

Mike
Click to expand...

Sorry Mike, I might not been clear - One big suck out closer to 37Hz and two peaks - one closer to 87Hz and another one closer to 120Hz. These were taken a long time back and at the time I was using the Pass X250.5. Since then I have changed speaker position multiple times. I will redo this weekend and repost. Sorry for the confusion.

Right now I am using the Nords.
 
Devg said:
Sorry Mike, I might not been clear - One big suck out closer to 37Hz and two peaks - one closer to 87Hz and another one closer to 120Hz. These were taken a long time back and at the time I was using the Pass X250.5. Since then I have changed speaker position multiple times. I will redo this weekend and repost. Sorry for the confusion.

Right now I am using the Nords.
Click to expand...

Go back to the Pass as well. Give that a try.


Sent from my iPhone using Tapatalk
 
Well it will be a little easier to solve this problem since you have REW and can see as well as hear the results. Check out the waterfall plots in addition to the frequency response ones. Look for modal ringing in the range of 50 -300Hz and for 300mS or more.

It takes trial and error and patience. Establish a centerline in the room and a way to mark the positions of the speakers and proposed listening position. Start moving the speakers fore or aft in 6" increments measuring as you go. Then move the listening position if you can once you've got the speakers and measurements sounding/looking good as that'll make an even bigger difference most likely. Once you've got the placements down try adding the bass traps.

Of course you could buy Jim Smith's book "Get Better Sound" if none of this makes sense. It's chock full of other good stuff as well.

Using subs adds a whole other level of complication but it does allow you to optimize sound stage separately from bass. I bet this is fixable without them.

Good luck!
 
Barry said:
Of course you could buy Jim Smith's book "Get Better Sound" if none of this makes sense. It's chock full of other good stuff as well.
Click to expand...

Thanks for the comment, Barry!

FWIW - I am currently writing a series on correct subwoofer set-up with "full-range speakers" over at the Copper e-magazine. But it won't be quite what most audiophiles expect, especially if they suffer from ACK.

ACK:

http://www.psaudio.com/article/the-ack-attack-and-un-common-knowledge/

Subwoofery:

http://www.psaudio.com/article/subwoofery-trick-or-treat/
 
Some updates:

After removing the traps, I felt something was missing with the sound. So I tried playing with the speaker positioning and re-adjusted to move it by a 1ft closer to the wall. I also had to move forward my listening position a bit. Bass is much better & taut but still a bit bloated.

I am getting the TWL Digital American high current power cords for the Nords tomorrow. Will update the thread after it has settled down.

@Mike, I tried the Pass, same results.

@Barry, will do measurements over the weekends.

@Jim, I have your DVD set for a while now. Is there anything in the book that is not covered in the video ? I am very much looking forward to the subwoofer setup series. I don't have any ACK whatsoever, can I get my hands on earlier ? :)
 
Dev - does it sound like the bass lingers longer than the rest of the music or is the bass just flabby and uncontrolled? Also, are the speakers spiked?


Sent from my iPhone using Tapatalk
 
Devg said:
Some updates:

After removing the traps, I felt something was missing with the sound. So I tried playing with the speaker positioning and re-adjusted to move it by a 1ft closer to the wall. I also had to move forward my listening position a bit. Bass is much better & taut but still a bit bloated.
Click to expand...

Seat position first - then, speaker position. Always.

Devg said:
@Jim, I have your DVD set for a while now. Is there anything in the book that is not covered in the video ?
Click to expand...

There are 202 tips in the book, so yes... :)

But first, are you receiving the FREE Quarter Notes newsletters for GBS owners?

Devg said:
I am very much looking forward to the subwoofer setup series.
Click to expand...

There have been several installments already. Issue 14, 15, & 16.

Devg said:
I don't have any ACK whatsoever, can I get my hands on earlier ? :)
Click to expand...

Sorry, unsure what you are asking. :(
 
Mike said:
Dev - does it sound like the bass lingers longer than the rest of the music or is the bass just flabby and uncontrolled? Also, are the speakers spiked?


Sent from my iPhone using Tapatalk
Click to expand...

Mike, the answer seems to be both. For some freq, it lingers a bit longer than others. I have listened to it briefly yesterday but I guess the only way to tell for sure is to take measurements. What I can say now is I can hear the bass but its not strong enough compared to the rest of the audio spectrum.

I have hardwood floors. Currently the speakers are not spiked. I am using Herbies speaker decoupling gliders. I had Stillpoints Ultra SS on them sometime back but there was some good bit of resonance coming from the lower part of the speaker base. Maybe I wasn't doing it right. I can put it back or try the stock cones one more time.
 
Jim Smith said:
Seat position first - then, speaker position. Always.
Click to expand...

So this is what confuses me - so help me understand. How can I hear the bass and soundstage without putting the speakers in the right place ? In other words, in order to determine the seat position, do I need to put the speakers in a predetermined location ?

Jim Smith said:
There are 202 tips in the book, so yes... :)
Click to expand...

Ok, sounds good.

Jim Smith said:
But first, are you receiving the FREE Quarter Notes newsletters for GBS owners?
Click to expand...

Nope. I bought the DVD set from Amazon.

Jim Smith said:
There have been several installments already. Issue 14, 15, & 16.



Sorry, unsure what you are asking. :(
Click to expand...

I wasn't aware of all the installments. How can I get them ?
 
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