How to optimize Subwoofer integration?

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richidoo

Re: How to optimize Subwoofer integration?
« Reply #20 on: 22 Nov 2017, 02:01 am »
Integration means flat FR and coherent phase. FR is easy, phase is harder.

The illusion of the dreaded "slow bass" is caused by phase errors of one sort or another, or all sorts. :)

The most common obstacle to phase coherence is that smaller main speakers most in need of subwoofer support usually have reflex ports with large phase errors. That makes blending with a sub problematic. You can stuff the ports to make them sealed, then phase integration is much easier, but then you need a sub that can play cleanly to higher frequencies than most inexpensive HT subs are capable of.

The Zu's look very capable for music. Seal up the ports of your main speakers and set the sub LP filter to 12dB/oct slope, set delay to 0, place subs same distance to your ears as the main woofers. A measurement system like OmniMic will help you adjust sub lowpass filter freq and sub volume level to achieve the best integration possible. 

A sealed sub has 12dB/oct rolloff, which matches the slope of the natural bass boost provided by the room reflections, aka room gain, or cabin effect. Larger diameter sub cone has a lower rolloff, so it is possible to pick the right sub cone diameter to have the sub rolloff match the room gain and yield flat FR down to 20hz, or whatever bass response is desired, without electronic EQ. The room volume determines the frequency where the 12dB bass boost happens. So smaller rooms need a smaller sub, while bigger rooms need larger sub(s.) Few people actually want flat FR to 20Hz for music, so this balance is one of personal taste, music style, and knowing what kind of bass response you personally prefer.

Edit: Sorry, I just realized this is in the Home Theater Circle, not music. Phase integration is less important for theater effects than FR. Multiple subs like Casler recommends will flatten FR throughout the room and excellent dynamics, also important for HT. Good luck

Nick77

Re: How to optimize Subwoofer integration?
« Reply #21 on: 22 Nov 2017, 01:04 pm »
If your going to purchase measuring devices here is a very good guide.

http://www.hifizine.com/2011/06/bass-integration-guide-part-1/


who?me?

Re: How to optimize Subwoofer integration?
« Reply #22 on: 26 Nov 2017, 11:21 pm »
Hey, thank you!

"Edit: Sorry, I just realized this is in the Home Theater Circle, not music. Phase integration is less important for theater effects than FR. Multiple subs like Casler recommends will flatten FR throughout the room and excellent dynamics, also important for HT. Good luck"

Thats OK!! I am new to the forums here and THIS IS FOR A "STEREO" SYSTEM.
I am only trying to integrate a sub not just for good music, but to understand the process of working in a sub. In fact, I have piqued in my Audio-philiac disease, and am not only tube-rolling, but "speaker-rolling". Ridiculous.

(Currently rolling--Dali Helicon 400, Dynaudio Contour S3.4, & Spatial M3 Triode Masters)

My listening room is roughly 12' x 19', with my system on one of the short 12' ends.

In other words, 12' for 2 full sized floor standing speakers and a sub doesn't seem like a lot to work with. e.g. If  each speaker is approx 1 foot wide, then for 2 speakers that is 2 feet taken off the 12'. So now i have 10' of space b/w speakers. Minus the footprint of the Zu sub, about 18 inches wide, that leaves me with 8.5' of space b/w these 3 speakers.

I guess I would probably leave 3 feet on each side of the stereo speakers to the outer walls. then put the Zu sub in the center b/w the floor standers, giving me 1.25 feet or 15 inches on each side of the sub. kind of tight.

Which makes me wonder, am i trying to fit a bigger sub than I should into this system?

One of the reasons I like this sub is b/c I thought that b/c it is so capable (eg down to 14hz), I assumed it would play well as low volumes. B/c I know if I turn it up too much, their would be too much sonic engird or cabin effect in my listening room .

RE: " The Zu's look very capable for music. Seal up the ports of your main speakers and set the sub LP filter to 12dB/oct slope, set delay to 0, place subs same distance to your ears as the main woofers. A measurement system like OmniMic will help you adjust sub lowpass filter freq and sub volume level to achieve the best integration possible."

Thx, will check out the OmniMic

"A sealed sub has 12dB/oct rolloff, which matches the slope of the natural bass boost provided by the room reflections, aka room gain, or cabin effect. Larger diameter sub cone has a lower rolloff, so it is possible to pick the right sub cone diameter to have the sub rolloff match the room gain and yield flat FR down to 20hz, or whatever bass response is desired, without electronic EQ."

yes, I want to avoid electronic EQ if I can.


Well, the big picture is that these are my plans for the next year:
"speaker-roll" the Spatials, Dyns and Dalis this winter and spring. Since my home is too hot in the summer to run tubes, I will tube-roll this winter mainly with the Dali's and Spatials, since the PrimaLuna can drive them well and there is a sub out.

But ultimately by next summer I want to be using the Dynaudio S3.4s and mostly a solid state amp system, in order to meet the increased power requirements of the Dynaudio Contours, as well as be much cooler than the hot tubes. I don't have AC in my rental .

(the Dynaudio Contour S3.4s need more raw power to really get the best out of them. With the PL, there is noticeable distortion. But this is understandable b/c the Dyn specs have already shown me that the SPL is 86db, 4 ohm. Versus the 92-3db SPL of the Dali's and Dyn's.  of course the Dyn speaker reputation for loving high power amps"

richidoo

Re: How to optimize Subwoofer integration?
« Reply #23 on: 27 Nov 2017, 02:42 am »
The Zu looks like a nice sub. 12" driver should be a good match for your room. Should approximate flat or slightly rolling off FR. Better to roll off than over drive the room.

12 feet width is not bad, especially with good room ratio like yours. Find where in the corners the speakers sound best according to stereo imaging (reflections from sidewalls) and bass modes. 3x5 ratio is always a good place to start, like tweeters are 2 feet from sidewalls, and 3.3 feet from front wall, or vice versa. Then you can slide you chair closer to change the stereo angle which affects the solidity of the center image, and again, the bass modes. It takes a while, and the OB speaker will behave differently fromthe box speakers, needing more distance away from the front wall.