Author Topic: Accurately Set Up a Subwoofer With (Almost) No Test Instruments  (Read 4779 times)

Offline windshear

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Re: Accurately Set Up a Subwoofer With (Almost) No Test Instruments
« Reply #15 on: November 03, 2013, 02:45:11 PM »
Windshear we are talking about low bass in this thread - well below 150hz or so .. eq is not effective at all at freqs that are above the schroeder freq.

Umm I didn't say otherwise....  ;D
« Last Edit: November 03, 2013, 02:48:05 PM by windshear »

Offline AcuDefTechGuy

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Re: Accurately Set Up a Subwoofer With (Almost) No Test Instruments
« Reply #16 on: November 03, 2013, 07:41:08 PM »
Windshear we are talking about low bass in this thread - well below 150hz or so .. eq is not effective at all at freqs that are above the schroeder freq.

It depends on the room, don't you think?

Not all situations are the exact same.

Some rooms may benefit, some may not benefit as much.
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Offline AlleyCat

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Re: Accurately Set Up a Subwoofer With (Almost) No Test Instruments
« Reply #17 on: November 21, 2013, 08:39:15 AM »
An interesting [?] titbit found in one of the hifi online blogs [Brent Butterworth, CEA-2010]  :

"The traditional lab measurement for evaluating subwoofers has been frequency response. It shows how even a subwoofer’s output is at different frequencies, and tells you the lowest and highest frequencies a subwoofer can reproduce.

I found out that frequency response provides an incomplete picture of subwoofer performance way back in the late 1990s, when I was conducting a blind test of subwoofers for Home Theater magazine. The test included a sub from Von Schweikert Research that according to my measurements had bass extension down to 19 Hz. Yet my listening panelists all thought that a B&W subwoofer, which had measured bass extension down to only 30 Hz, had better deep bass output.

I decided then to try to find a measurement that would correlate with my panelists’ results. I finally hit on something when I tried a crude distortion test, turning up each sub’s volume until it hit 10% total harmonic distortion at 20 Hz, recording the level, then repeating the test at 30 and 40 Hz. At the higher levels used for the distortion test, the B&W’s larger driver and enclosure produced much more output at 20 Hz than the Von Schweikert sub did.

To understand why, imagine you had a sealed-box subwoofer with a 12-inch woofer, with response that decreases by -12 dB/octave below 32 Hz. Well, why couldn’t you make it flat to 20 Hz by just hooking up a graphic equalizer and boosting the 20 Hz band by about +8 dB? You could, and at low levels, the frequency response measurement would tell you the sub’s flat to 20 Hz. But raise the level and one of two things will happen. The woofer might hit its maximum excursion (the maximum distance it can move forward or backward from its resting position). Or the amp might run out of power—no surprise, because that -12 dB/octave drop in bass response means it will take more than 6 times as much power to get the same volume at 20 Hz as at 32 Hz.

“For home theater enthusiasts, I recommend a sub that delivers at least 120 decibels at 40, 50, and 63 hertz, and at least 110 dB at 20, 25, and 31.5 Hz.” Finding a sub that meets those criteria won’t be easy, however, since subwoofer manufacturers cite performance in terms of frequency response (i.e., –3 dB at 25 Hz) rather than output levels at the Low Bass (40, 50, 63 Hz) and Ultra-low Bass (20, 25, 31.5 Hz) tiers specified by the CEA-2010 subwoofer measurement standard"
"Not everything meaningful is measurable, and not everything measurable is meaningful" - Floyd Toole

Offline Triton

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Re: Accurately Set Up a Subwoofer With (Almost) No Test Instruments
« Reply #18 on: July 09, 2016, 05:35:42 PM »
Very good article, cant wait to try it!

Offline MSAllen

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Re: Accurately Set Up a Subwoofer With (Almost) No Test Instruments
« Reply #19 on: January 29, 2017, 11:26:48 AM »
Use a Lyngdorf DPA1 to integrate your subwoofer (or to tune you entire system). It results in an incredible improvement to the sound, regardless of the quality of your equipment or the room tuning you have done. I have used it with Proac Response 1sc speakers and an old Kef subwoofer in an untreated room and used it to tune the entirensys Em, as well as with a Wilson Benesch Torus and Wilson Benesch Bishop speakers to integrate just the subwoofer and in both cases it provided absolutely seamless integration. If anything, tuning the entire system and room with it provides even better results than just integrating the subwoofer.
A little miracle box, if ever there was one!

Offline bbe22

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Re: Accurately Set Up a Subwoofer With (Almost) No Test Instruments
« Reply #20 on: January 29, 2017, 12:58:46 PM »
at that price it better be a little miracle box..............


Description
Lyngdorf Audio DPA-1 Digital Preamplifier with RoomPerfect room correction
Power consumption: 4 watts (Standby mode)
Power consumption: 35 watts (Operate mode)
Width: 450mm / 17.72 inches
Depth: 355mm / 13.98 inches
Height: 100mm / 3.94 inches (including feet)
Net weight: 7.4 Kg / 16 lbs.
Price: $5700 USD (approximate)
Please visit www.lyngdorf.com for more information on specs and features.


Offline Rodney_gold

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Re: Accurately Set Up a Subwoofer With (Almost) No Test Instruments
« Reply #21 on: January 29, 2017, 01:44:14 PM »
If yoiu want a cheaper option buy a 2nd hand KrK ergo if you can get one , it has room perfect built in ..FDLSYSS had a few new ones at around R4k..not sure if he still has.
Or use DIRAC or one of the minidsp units
Roon/tidal > Squeezebox touch> 2x Devialet D premiers>  Vivid audio Giya G1 spirits ..fully treated room

Offline fdlsys

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Re: Accurately Set Up a Subwoofer With (Almost) No Test Instruments
« Reply #22 on: January 29, 2017, 03:10:18 PM »
Still have a couple of brand new ones, thanks Rodney.
The four building blocks of the universe are fire, water, gravel and vinyl. Dave Barry
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Offline MSAllen

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Re: Accurately Set Up a Subwoofer With (Almost) No Test Instruments
« Reply #23 on: January 30, 2017, 11:19:01 AM »
If yoiu want a cheaper option buy a 2nd hand KrK ergo if you can get one , it has room perfect built in ..FDLSYSS had a few new ones at around R4k

I'd forgotten about the KrK Ergo. Exactly the same RoomPerfect correction as the Lyngdorf, with microphone to measure room acoustics and all (the process sounds like a submarine sonar...) but limited to correcting bass and midrange (as I remember), rather than the full audio range like the DPA1. Not really a problem, as that is where the bulk of any room correction occurs anyway and easily covers the audio range required to integrate subwoofers perfectly.

Great little unit - I used it before I could afford the DPA1 to integrate the same Kef subwoofer I mentioned before with a pair of Revel M20 speakers and it worked exceptionally well. Only down side is that it was meant to correct room acoustics for a home recording studio, so uses 1/4" jack plugs, rather than the usual RCA connectors. Unfortunately no longer manufactured (probably took away Lyndorf DPA-1 sales...), so you usually have to find a used one.

Can't overstate how well it integrates subwoofers - just absolutely seamlessly.
« Last Edit: January 30, 2017, 11:27:52 AM by MSAllen »

Offline Rodney_gold

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Re: Accurately Set Up a Subwoofer With (Almost) No Test Instruments
« Reply #24 on: January 30, 2017, 11:43:18 AM »
The Ergo does 20-500hz correction , I just used 1/4" trs to single ended converors when I had it
The problem is that you cant amend the house curve
However , you can do the correction and then add the house curve from the computer side of things
I had KrK vxt8's , their 12s sub and an ergo .. my aim was to put together a system at under R20k that would really perform and be a giant killer. and it did!!
Roon/tidal > Squeezebox touch> 2x Devialet D premiers>  Vivid audio Giya G1 spirits ..fully treated room

Offline AlleyCat

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Re: Accurately Set Up a Subwoofer With (Almost) No Test Instruments
« Reply #25 on: August 06, 2017, 11:29:04 AM »
The link on the OP does not work anymore, here's the link:

https://www.digido.com/portfolio-item/subwoofers/
"Not everything meaningful is measurable, and not everything measurable is meaningful" - Floyd Toole