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I finally finished my near-field Contemporary VBSS build!!



I just need a little help setting up PEQ in NX Edit. I cannot get REW results anywhere close to mtg90s outdoor response below. Maybe this is normal?


My response baseline still has issues after moving the VBSS around as much as possible, but I was able to get it somewhat flat by losing
a few overall db. (It seems that the sofa is what is causing the 50hz dip)

Baseline in Red - PEQ in blue (VBSSs w/1099s)

(LFE crossed @ 80hz, no treble, bass, bass boost, etc on Onkyo 40 Volume AVR, VBSS tune is 20hz by mtg90 on channel A)

I was going to put a low shelf +6db but am afraid that would kill my drivers (xmax)
So instead I used a +10 PEQ @23hz VS a High Shelf @ 30hz to lower 10 Db above 30hz. Was this the right way to do it?
 

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what did you do for bracing? and did you double the front baffle?

I went with some crude looking window bracing that you can see on my build thread and only a single layer baffle but I did add blocks under the driver so the t-nuts had more to bite into and I will flush mount the driver. Since this isn't a functioning unit yet, maybe you shouldn't take my advice but I think it will be ok. :eek:
 

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Voltage Limit

If I am running 2 vbss's off of one channel of a 3000dsp do I double the voltage limit? so 84Vp X2 = 168Vp:confused:

-31Hz tuning
Configuration:

Bi-Amp1,
limiter=84Vp, hold=20ms, release=20ms

Filter/crossover:
Highpass 25hz Butterworth 18dB
Lowpass 300hz Butterworth 12dB

DEQ:
Band 1
Gain 6dB, 28hz, Q=1.00, type BP, Threshold -27dB, attack 5ms, release 20ms, ratio 1:10
 

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Discussion Starter #1,467
I finally finished my near-field Contemporary VBSS build!!

I just need a little help setting up PEQ in NX Edit. I cannot get REW results anywhere close to mtg90s outdoor response below. Maybe this is normal?


My response baseline still has issues after moving the VBSS around as much as possible, but I was able to get it somewhat flat by losing
a few overall db. (It seems that the sofa is what is causing the 50hz dip)

Baseline in Red - PEQ in blue (VBSSs w/1099s)

(LFE crossed @ 80hz, no treble, bass, bass boost, etc on Onkyo 40 Volume AVR, VBSS tune is 20hz by mtg90 on channel A)

I was going to put a low shelf +6db but am afraid that would kill my drivers (xmax)
So instead I used a +10 PEQ @23hz VS a High Shelf @ 30hz to lower 10 Db above 30hz. Was this the right way to do it?
The in room response will not look like the outdoor measurement. Every room will influence the response of the subwoofer differently and the EQ settings in the VBSS file only provide minor response shaping and largely just correct for the low frequency rolloff the Driver/enclosure normally present. Once placed in room those settings can be changed if it will help flatten the response.

Your blue EQ'ed response does not look too bad.
 

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The in room response will not look like the outdoor measurement. Every room will influence the response of the subwoofer differently and the EQ settings in the VBSS file only provide minor response shaping and largely just correct for the low frequency rolloff the Driver/enclosure normally present. Once placed in room those settings can be changed if it will help flatten the response.

Your blue EQ'ed response does not look too bad.
Thank you so much for responding sir. It sounds like I was headed down the right path.

I just purchased a Denon with MultEQ and wow does it make life easier from direct hdmi from rew laptop to the Audyssey room corrections. (It is simply amazing what advanced DSPs in the new AVRs can do compared to the old Analog (non HDMI, no Room Corrections) AVRs.

I can't wait to see what The Audyssey DSP plots out like because it sounds so smoooooth. Respectable.
 

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Since this thread has been around for a good while now, how are all the horizontally oriented drivers holding up in these end table builds?

This reminds me to go test out my old RS HiFi 15s. 13 years pointed at the ground. I haven't fired them up in about five years, so it could be interesting...
 

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https://www.bhphotovideo.com/c/product/1427356-REG/behringer_nx3000d_3000_watt_class_d_power_amplifier.html?ap=y&gclid=Cj0KCQjwgezoBRDNARIsAGzEfe7W9MMDee9FlndQC_gszkaSzxAPm7Elh6BJeCx6V2NaG-jw4hAzzvEaAnKrEALw_wcB&lsft=BI%3A514&smp=y

Nx3000d for $308 at b&h photo. With the pa460 on sale as; well it's; a good time to make these
 

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Thought I'd share here. I built a modified version of the vbss. Originally I was going to paint it just like a Rubik's Cube but due to WAF concerns I used stained rift sawn oak veneer instead. Powered with a Fan Modded Inuke NU1000DSP. Since I still have rambunctious children I put a grill over the driver even though it's downfiring.



Do you have a link to the gallery? The thumbnail images are really small. Thanks!
I have been lurking here for the past week, reading oh sooooo many posts and viewing all the great builds. I live in Canada and have access to these subs for a better price than the Pa460's, which would cost me $345.42 delivered for 2, vs $269.34 for 2 of the Rockville subs. Will they work or should i just shell out the rest for the Pa460's?
+1

Also I'd bet re-positioning your sub(s) may help with that null (see the subwoofer crawl recommendation). Fingers crossed!
So I fired up REW for the first time to run some measurements on my pair of VBSS tables. I really shouldn't have. Now I want two more...

I've so far been fairly happy with the performance. I fired up a 40Hz sine wave and walked around my room for the first time last night and realized my MLP is in a void and there is a really large summing point (is that what you call it?) about half way between my MLP and my screen. In that zone, its a LOT louder (I didn't take measurements there yet).

Any thoughts? Yes, 2 more VBSS are already being planned but anything I can do with placement in the meantime? I have a feeling my room is causing big problems. BTW my room opens to two bedrooms and a bathroom to the left, and to an office and the stairs to the right.

Thanks pops love your hair done today but I will be back
Thanks

Sent from my Pixel 3a using Tapatalk
 

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So I built two VBSS boxes that are tuned to about 15-16hz. They sound GREAT, and I haven’t even put them through the ropes due to concern about the structure of my home 😉

However I have some odd sounds during only a few soundtracks. During Interstellar right after the exit of the black hole there is a long drawn out bass note. I get a “fluttering buzz” sound right at the end of the bass track. I tried to capture it on video. The only other time I’ve noticed this is during Dunkirk, another Nolan film.

I am using the 15hz profile on the NX3000D, running in dual mono.

https://1drv.ms/v/s!ApqHiglAkZe-gqoWU_TvclRNQjrNww

Thoughts? Did I mess up my design?
 

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Does it go away at lower volumes?
Yes it is much less noticeable if I turn down the subwoofer, however then my bass track becomes completely neutered.

It’s odd, some tracks the bass sounds perfect with no issues at all. Example would be Blade Runner 2049, sounds amazing. However I notice issues with Interstellar, Dunkirk, general cable TV watching at time I notice it. I never noticed this before. I would say it’s not responding well to very low frequencies, but I do hear it the odd time during cable TV, and during Dunkirk’s constant music track.

I did try the 20hz profile, same thing. I’m not familiar enough with the DSP adjusting on the NX3000D to be able to say if any tweaks would help.
 

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Discussion Starter #1,477
Run several sine wave test tones at different frequencies to see if you can isolate the noise to a specific frequency range. If you have REW you can use it's built in sine wave tone generator, otherwise there are youtube videos of sine wave sweep tests you can use. Check 40Hz down and see if anything stands out at a certain frequency.
 

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Hey gents, what’s the recommended method for integrating a pair of VBSS’s in with four um18-22 mini marty’s? I would think either:

1. Run all subs “full range” (all mini marty’s and vbss’s from their respective port tunes to the crossover); or,

2. Run the mini marty’s from their port tune to some mid bass value, and run the vbss’s from that mid bass value to the crossover point with the speakers.

I have two nice locations in my room that are good and flat across the mid bass spectrum and I’ve been itching to add some mbm’s ...
 

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I'd run them all full range if you can, more sources give you the benefit of response smoothing and increased output over using them in their own separate frequency ranges.
 

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Does the driver and port placement matter in this build? Can I put the driver down firing on the 20.5x23.5 face? I know the ports need to be extended on the short end for the tuning, but does it matter otherwise?
 
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