Humps at 43Hz, 90Hz, and 110Hz

[Summit]

Am not an expert, but to me the biggest “problem” with your room seems to be that it is long and narrow. I would try with less (or no) toe in and hear how it sound and measure. Corners are problematic for bass and placing tube traps there is not so much for absorbing the bass as not letting the bass get to the corners there it will be amplified big time.   

[firedog]

Hi Chris-

I have a big hump at around 40hz in my room, and Roon does a good job with it's EQ fixing the problem for the most part. I will probably invest in a mic and some RC software soon to fix that node more precisely. 

My personal experience is that those triangle bass traps make a big positive difference. They won't solve all the problems on their own, but I bet they will help. 

[The Computer Audiophile]

1 minute ago, firedog said:

Hi Chris-

I have a big hump at around 40hz in my room, and Roon does a good job with it's EQ fixing the problem for the most part. . I will probably invest in a mic and some RC software soon to fix that node more precisely. 

My personal experience is that those triangle bass traps make a big positive difference. They won't solve all the problems on their own, but I bet they will help. 

I'm also investigating some room correction options. I have the UMIK-1 for measurements. I've also been talking to @mitchco who is so helpful it's incredible.

 

I have an email into Jon at Trinnov to check out one of its two channel devices. I want to try the digital output of one so I can use the DAC of my choice. 

 

All neat stuff to try.

 

Looking forward to the bass traps.

[firedog]

12 minutes ago, The Computer Audiophile said:

I have an email into Jon at Trinnov to check out one of its two channel devices. I want to try the digital output of one so I can use the DAC of my choice. 

The Lyngdorf units would also do the trick well, IMO. They include amps as well as preamp and RC, but they  do have a digital out.

[Dr Tone]

58 minutes ago, Summit said:

Am not an expert, but to me the biggest “problem” with your room seems to be that it is long and narrow. I would try with less (or no) toe in and hear how it sound and measure. Corners are problematic for bass and placing tube traps there is not so much for absorbing the bass as not letting the bass get to the corners there it will be amplified big time.   

 

I don’t think I’ve seen a Wilson setup without aggressive toe-in.  Very interesting to see the end result after the rep visits.

[firedog]

3 minutes ago, firedog said:

The Lyngdorf units would also do the trick well, IMO. They include amps as well as preamp and RC, but they  do have a digital out.

Oh, and also DEQX. AFAIR, they have a unit which is just digital in and digital out. I've never heard it, but it has a great reputation. One advantage of DEQX is that their techs will log on and do your room test and correction filter  for you in your room. 

[rando]

Just to make doubly sure.  Thor's Hammer would only exacerbate the issues?  👂

 

Idea to move speakers closer to front wall intrigues me.  Along with the flurry of physical and acoustic measurements Wilson rep is sure to perform.  Factory stated minimum distance mid and high will align (8' or 9', I don't have it in front of me) has to be preserved, or bettered, in any adjustments.  

[semente]

3 hours ago, Summit said:

Am not an expert, but to me the biggest “problem” with your room seems to be that it is long and narrow. I would try with less (or no) toe in and hear how it sound and measure. Corners are problematic for bass and placing tube traps there is not so much for absorbing the bass as not letting the bass get to the corners there it will be amplified big time.   

 

Toe-in wont affect bass.

The ceiling is too close for no toe-in.

[skatbelt]

18 hours ago, The Computer Audiophile said:

I'm also investigating some room correction options. I have the UMIK-1 for measurements. I've also been talking to @mitchco who is so helpful it's incredible.

 

I have an email into Jon at Trinnov to check out one of its two channel devices. I want to try the digital output of one so I can use the DAC of my choice. 

 

All neat stuff to try.

 

Looking forward to the bass traps.

 

Finally

 

[bluesman]

On 7/17/2019 at 4:15 PM, The Computer Audiophile said:

13.8 feet wide

25.8 long

9 feet high

 

The wavelength of a 44 Hz tone is ~25 feet, Chris. And a 110 Hz cycle spans about 11 feet.  Your main axes are almost exactly at full and half wavelengths for your problem frequencies, and the sloping ceiling tunes the room with continuous half and quarter wave reinforcement for your problem humps.  Moving the speakers will probably not reduce this by much, although “softening” the end walls and corners a lot should help.

 

Depending on its dimensions, that stairwell may be making it worse by acting as a bass port if you consider the room to be an enclosure and the speakers as drivers within it.  You might try blocking and/or narrowing it with something to see if there’s a meaningful change.

[Ralf11]

Exactly.

 

BTW, have  a hand mirror available in case the Wilson rep doesn't bring one in his tool kit

[Foggie]

Maybe its just me, but It took me a long time with a crap load of experiments/configurations dialing in my rig.  Not that it was a full time chore day in and day out and I know I'm stating the obvious, but placement is so absolutely critical if one is driven to get the most out of speakers.  Maybe others can do this in a few days and be done with it, dunno.

 

A foot or inches (even less) forward, backwards, distance between spkrs etc.. can will have a profound influence.  Gotta put in the time and have the motivation to do as it is "work" but the process can be fun to a degree.  

 

Talking about DSP, getting processor pre's/DAC's et al, seems a bit premature at this point as Chris is only into this for a few weeks? 

 

IMHO getting everything dialed in the best as possible acoustically first and then sitting with that for awhile seems logical.  This can req moving treatments around as well - which is a PITA as Macgyver'ing treatments temporarily is challenging.  At least when I did that, besides the learning experience and getting to know your room, it made significant changes in sound and gave me the opportunity to decide on what sound I preferred.  I'm sure the Wilson indiv will get things dialed in wonderfully. 

 

Getting proper room measurements is certainly part of it to make educated changes etc..

 

As an additional alternative, I'd even go as far as trying to get a room play session with Jim Smith, which is a different course of action, but there have been plenty of experienced indiv with very positive outcomes.  If I had the funds I'd give it whirl.

[GregWormald]

One suggestion I ran across many years ago:

 

If the seating position(s) are relatively fixed then the details about speaker position can be gained by putting the speaker (yeah--light speakers!) at the listening position and then walking around the room to find the best response. With reciprocity this should be the best position for the speaker.

 

My recent experience:

 

I decided to review the set-up of my speakers. The initiative was spurred as I noticed a slight shift of the balance to the left, made more noticeable by more attentive listening to the increased clarity of my old favourites (I bought an ultrasonic cleaner for my 750 LPs). I did check other sources and the shift was there too, but had gone basically unnoticed. It wasn't large by any means but it started to bother me.

 

I've always been fairly fussy (some might say anal😃) about set-up so I wasn't really expecting much. Boy, was I surprised.

 

My room is very asymmetrical, with a cathedral ceiling of about 3 metres. The speakers are approximately 750 mm from the wall, 2.7 metres apart and my listening chair sits 3.5 metres back from them with 2.8 metres to the wall behind me. I've spend a fair while getting this set-up and it works well. I'm not convinced it's perfect but I got tired of moving heavy speakers and furniture.

 

I put my chair on the centre-line between the speakers, got the tape measure out and proceeded to measure everything.

 

One speaker was closer to the wall by about 30mm. One speaker was angled more than the other with a 15mm difference when comparing the spike positions to the wall behind the speakers. One speaker rocked slightly while the other was rock solid to the concrete slab. The rocking speaker was tilted down by about two turns of one thread locking nut. (They were recently upgraded and, as far as I could tell at the time, were replaced in the same positions that they had had previously. I probably wasn't fussy enough as I was too anxious to enjoy the upgrades.😞)

 

I evened everything up and lastly put the listening chair precisely on the apex of the chair/speakers triangle. All measurements were now the same within a mm or two.

 

I sat down to listen, and WOW. The 'image' was now precisely in the centre between the speakers with some sounds extending beyond the outside of the speakers by several feet. The image was exceptionally stable and the clarity of the music improved again. My involvement in the music was so improved that I've had trouble reading, having to stop and just listen, eyes closed.

 

Problems:

As above, I'm falling behind in my reading.😧😧

 

Moving my seating more than a very few inches from the 'hot spot' means the image shifts to the right or left. The quality is there--but the centre shifts. (Speculation: The shift seems more than can be explained by loudness issues and I'm wondering if it could be related to the sounds from the right and left no longer arriving simultaneously. 5000 Hz (below which most of the music lies) has a wavelength of 2.7 inches, so moving 3 inches right or left would delay the long side by up to one whole wavelength.

 

Chris--good fortune in getting the speakers and room tuned-in.

 

[Rt66indierock]

On 7/18/2019 at 9:30 AM, The Computer Audiophile said:

I'm also investigating some room correction options. I have the UMIK-1 for measurements. I've also been talking to @mitchco who is so helpful it's incredible.

 

I have an email into Jon at Trinnov to check out one of its two channel devices. I want to try the digital output of one so I can use the DAC of my choice. 

 

All neat stuff to try.

 

Looking forward to the bass traps.

 

Keep me updated on humps and bass traps. I have a long drive ahead of me with the Heresys.

[Ralf11]

I hope everyone is reading thru the Handbook...

 

key term: standing wave

[Bob Stern]

On 7/18/2019 at 9:30 AM, The Computer Audiophile said:

I'm also investigating some room correction options. I have the UMIK-1 for measurements. I've also been talking to @mitchco who is so helpful it's incredible.

 

In theory, peaks can be corrected very successfully by EQ (room correction), whereas narrow dips cannot be.  I expect mitchco will be able to get great results for you with Acourate or REW.  

[cjf]

@TheComputerAudiophile (Chris)

 

I'm curious if you happen to also have a good SPL meter on hand by chance? When I was recently setting up my new room/speakers/subs I spent quite a bit of time on the physical placement of the speakers/listening chair with the help of my SPL meter. I had a 25db difference in output between the Right/Left Main channels I was fighting with at certain Freq's. It was super obvious when sitting in the listening chair too. The Right channel would simply overpower and take precedence of the soudstage and I was losing faith.

 

Then I ended up playing Tones via REW at the worst Freq's at close to my REF Level. I would then start to crawl around on the floor near the problem speaker with SPL meter in hand. At one point, only a few inches away from the current location of that channel I found a Lull that was about -7db lower in level. I moved the speaker in that spot and "Re-Aimed" it at the listening chair. I then moved to the listening position and did the same thing near ear height with SPL meter in hand. Again about 2inches to the Left of the current chair position I found another LULL that returned an additional reduction of -3db. So after all was said and done I reduced my channel imbalance by -10db just by a few small corrections in physical location.

 

Now this isn't to say the same thing will happen in your case but I suspect it may return some decent results especially if you notice that its one channel being the biggest culprit in causing the Spike. All in one measurements are great to see the final result of all speakers working together but these types of measurements also tend to Mask/Hide what each individual channel is doing to contribute to the All channels measurement. Especially when out of phase signals come in contact with each other mid air

 

Another benefit in getting as much as you can from physical corrections first is that it reduces the amount of work the software correction filters will need to do; if you decide to use them of course. IME, this results is less loss of your volume headroom and reduces the amount of Gain you need to have in reserve from your chosen Pre/Dac that is driving your Amps.

 

One thing I found out pretty quick was that you run out of Vol output real quick once room correction is used (Plan for a solid -20db being chopped off your output level and that number goes up from there if the software has to do a lot of the hard work to correct things you could have dealt with in the physical world by moving speakers/chairs a few inches..etc). In my case I was lucky to have two DAC's capable of studio level output voltages to drive my Amps which gave me some of my Vol output back that I lost due to room correction.

 

Hope this is useful and good luck getting things setup. Its fun stuff either way

[semente]

On 7/26/2019 at 3:49 PM, Foggie said:

I'd even go as far as trying to get a room play session with Jim Smith

 

The incredible Jimmy Smith? I though he was dead...

 

https://www.youtube.com/watch?v=SL0VcHTWDeU

 

[daverich4]

27 minutes ago, semente said:

 

The incredible Jimmy Smith? I though he was dead...

 

https://www.youtube.com/watch?v=SL0VcHTWDeU

 

 

Not 100% sure if you’re kidding or not but on the off chance you aren’t...

 

http://getbettersound.com/index.php