Jamo C97 II with 2 KLH Subs, UMIK-1 with REW and Equalizer APO

[bleepbloop]

All,

I have finally gotten around to using my new C97 II speakers, the UMIK-1, REW, and Equalizer APO. For the relatively cheap gear I have, this is the best sound I have been able to achieve in my house and the Jamo C97 II solved my lacking musical punch problem. I did find what I think might be a cancelation in my listening area at 200hz. I just can't seem to correct the 200ish hz range when both speakers are playing at the same time. It is audible with a tone but not that audible in music or at least that I can tell. 200hz is much louder if I move about 1.5 feet left or right but in dead center, it's -10db or so by the UMIK-1 measurement. Any suggestions, maybe add some physical room correction? This is my 2nd effort with filters, I spent about 4-5 hours on this getting all software and hardware setup and doing the measurements and filtering.

How perfect should I expect in room to be on a chart? +/- 5db, +/- 3db? The attached image is with REW filters loaded into Equlizer pro (corrections are applied). I brought up the right filter level by 0.5db after I took the image attached. I need to re-run REW but the L and R channels seem more even to my ears now. Purple line is L and R with both subs. Dark blue line is Left with both subs and blue/green line is Right with subs.

Some notes: Subs are set to assist all the way up to 100hz. The speakers are set to full range. I used the house curve at default within REW to create my filters with 68db being the target average. I used left + subs and right + subs for measurements, both subs and speakers are equal distance from back wall and listening area and left and right equal as well. I cannot split left and right subs (yet), my receiver has two sub outs but I assume they are the same mono channel as they both always play even when L/R are playing separately. This did mean both left and right speaker filters applied to both of subs at the same time unfortunately. I did db balance all channels and both subs individually at least. One by one getting their db readings within 0.5db or so, this meant turning off or unplugging speakers/subs etc.

I have to thank this forum for recommending a UMIK-1 to me, music is so much better on this setup than it was before.

Cheers!

 

[Maginness]

I have some C97 II myself. In my main listening area, I could never get them dialed in. The room is awful for a bunch of reasons. I ended up changing them for stand-mount speakers + 2 subs. Gave me better positioning options.

My C97 II are in the garage with a miniDSP DDRC-24 (Dirac) and I'm super happy with how they sound. I don't have any REW charts to share but did use a UMIK-1 and Dirac to set them up.

 

[bleepbloop]

I have some C97 II myself. In my main listening area, I could never get them dialed in. The room is awful for a bunch of reasons. I ended up changing them for stand-mount speakers + 2 subs. Gave me better positioning options.

My C97 II are in the garage with a miniDSP DDRC-24 (Dirac) and I'm super happy with how they sound. I don't have any REW charts to share but did use a UMIK-1 and Dirac to set them up.

Mine are quite bad in their current position below 100hz for equalizing. Huge low db output from 63hz to 97hz or so. My subs were once in the same position as the speakers and I had the same issue so speaker/sub placement definitely matters. I moved the subs farther away from listening area closer to the rear wall and that resolved the issue with the subs, it was so bad it was extremely audible. When I get rid of my current sectional couch for 3 comfy chairs, I'll probably move the speakers further out from the back wall and re-test everything. For now, with subs, they sound fantastic, without subs, I can hear the missing frequencies. Long term goal is a room engineered specifically for speakers and subs.

Edit: Attached Speaker only REW results. This is with correction. Bad from ~63hz to 95hz. The 200hz dip is there too.

 

[ReDFoX]

Mine are quite bad in their current position below 100hz for equalizing. Huge low db output from 63hz to 97hz or so. My subs were once in the same position as the speakers and I had the same issue so speaker/sub placement definitely matters. I moved the subs farther away from listening area closer to the rear wall and that resolved the issue with the subs, it was so bad it was extremely audible. When I get rid of my current sectional couch for 3 comfy chairs, I'll probably move the speakers further out from the back wall and re-test everything. For now, with subs, they sound fantastic, without subs, I can hear the missing frequencies. Long term goal is a room engineered specifically for speakers and subs.

Edit: Attached Speaker only REW results. This is with correction. Bad from ~63hz to 95hz. The 200hz dip is there too.

How many points did you use to make these averaged measurements?

 

[bleepbloop]

How many points did you use to make these averaged measurements?

Only one in these charts, dead center evenly between the L and R channels and is the average of 3 measurements for each. I did measure 6 inches left and 6 inches right, the results were within ~1db through the entire range. To my ears there isn't much change until I get about 1.5ish feet left or right away from dead center which is outside my listening area.

 

[staticV3]

@bleepbloop it's still a matter of personal preference of course, but your in-room response is not supposed to be flat.

Neutral speakers will show show a roughly 0.7dB/Octave drop in frequency response when measured in-room, or a roughly 5dB drop from 100Hz to 20kHz :


Erin did a great video about this: https://youtu.be/_tnWB8Rl0Ms

 

[bleepbloop]

@bleepbloop it's still a matter of personal preference of course, but your in-room response is not supposed to be flat.

Neutral speakers will show show a roughly 0.7dB/Octave drop in frequency response when measured in-room, or a roughly 5dB drop from 100Hz to 20kHz :
View attachment 330023 View attachment 330024

Erin did a great video about this: https://youtu.be/_tnWB8Rl0Ms

Thanks! I did apply a slight house curve to mine where the lows are slightly higher volume than the higher frequencies, at least that was the goal. I truly do love the sound I have currently so I am not sure if I'll make many adjustments for a while. I would like a receiver or DAC that has true left and right sub channels, Emotiva makes one I believe. That'd allow me to get truly equal sound out of each side vs subs doing both L and R at the same time.

 

[bleepbloop]

Given that the 200 Hz cancelation is not significantly affecting your music listening experience, would it be more beneficial to focus on optimizing the overall frequency response rather than meticulously correcting this specific frequency range?

That is a good question. I'm not entirely sure what an audible difference there is in 3db or so in the higher frequencies. The lower ones seem easier to my ears to hear differences in. I am not sure what the "gold standard" is for +/- db. In a more perfect world I'd love to see the chart +/- 1db or less through the entire range, I'm just not sure that's possible in my mostly concrete room with random things all over and no physical room corrections. Maybe adding bass traps would help with 200hz? I'm totally new to room equalization.

 

[bleepbloop]

I decided to replace the KLH subs with DIY subs. I chose the UM10-22 x2. 2 boxes, one per sub. Tuning to 21hz or so. 2.3 cubic foot boxes with driver, amp and port displacement calculated into the box. Port will be 17 inches long 3" flared, 1 per box. At my listening volume, hopefully I do not get port chuffing. If I do, I'll have to go up a size and curl the port around.

 

[Halcyon75]

My apologies for reviving this thread but it's the only one I've found with anyone discussing the C97-II.

I'm finding that if I set the crossover lower than 60hz it's like the room swallows the bass. Sure the sub fills it in but because of where it's located setting it's x-over higher than 80hz causes it's output to be localized...

I've kinda McGuyvered it a bit by setting my mains to 40 hz and my sub to 80hz then level matching the sub to the mains, that's help to remove the localization quite a bit. I have my subs gain set to less than 50%.

My speakers are about 8" from the front wall so I use it to amplify the bass, any further and the bass vanishes...

 

[bleepbloop]

I had issues with 60-95hz suck-out with the C97-II in many positions. It took quite a while testing different placements and using my UMIK-1 calibration microphone to find a decent positioning. For me, the best position was 13 inches away from the back wall to the nearest corner of the speaker. The nearest corner is the inside corner, the corner which faces the other speaker. For the the side wall, the corner nearest this is 11.5 inches away and is the outside corner. My speakers are on axis facing directly at me, and I am 10.5 feet away from the front of the speaker. My room is 25 feet deep, so I sit roughly in the middle. It's my basement, the walls are concrete. Your setup may be different. Currently, I cross them over to the subs at 80hz for movies. For music, I let the speakers go to 40hz unless I am listening loudly. The subs still fill in some between 20-80hz when I listen to music but they don't do a ton. If I turn off the subs, it's difficult to hear much difference under 70db.

 

[Halcyon75]

I believe I have finally dialed in the C97 II.

1. 18" from the front wall
2. I'm using an AVR so I've sent the front to Full Range/Large
3. Double Bass is on for watching movies (SW does not play while in 2ch music mode)

OMG these speakers are incredible. My SPL meter measures bass at 42hz in room and my ears and chest believe it. The mistake I was making was that I was playing them in Pure/Direct mode and the sound is fine but setting it to full range bypasses the SW when in Music mode. If I chose TV on my TX-NR696 the sub will be engaged. This was a feature I was previously unaware of. Of course without the SW how much bass i feel is going to be content specific, i.e. it will play closer to how it was recorded but bass heavy and more modern tracks hit hard.

Ultimately I had to put them back to 8" from the front wall (Happy wife and all). The impact on bass was minimal. I can now play them without the use of a sub.

Yes, I did have to apply mild EQ tuning but primarily to the midrange (+1db on 640hz, 1khz and 2khz and -1db on 10 & 16 khz) I also have -1db on the treble tone control.

While messing about I played a few bass albums I have from Bass Mekanik, Bass 305 and Bass Dominator that was when I saw the speakers real potential. This leads me to a question; could that listening session of the Bass tracks caused additional burn in on the speakers leading to improved sound?

 

[bleepbloop]

Most argue that there is no burn in on speakers. I sort of feel like the overall sound improves a bit with time. I think the larger drivers loosen up a little and move more freely and the high end isn't quite as harsh, backing this up with measurements has never happened. I am glad the speakers are working for you, I like them as well. I too use them set to "large" on my Sony receiver. The new subs I built play from 17hz to 90hz ~flat, my amp increases output at 30hz so I trim that out digitally. I am about -3db at 15hz. For music, I still can hardly tell a difference in bass with subs on/off if I listen at volumes up to ~75db. There is maybe a bit more kick with subs on, and anything under 35hz I can tell a difference. Most music I listen to doesn't seem to go below 38hz. For movies, the subs really do make a difference. The extremely low frequencies in movies I can't even hear but I can feel them (less than 20hz), also, random things just shake and vibrate in my basement, I hear that with those low frequencies too.