RE: I Need More Help To Understand

Posted by tomservo (M) on October 20, 2010 at 09:45:35

In Reply to: I Need More Help To Understand posted by thetubeguy1954 on October 20, 2010 at 08:29:42:

Hi Tom
Answer one , yes. The lowest room mode is usually in the neighborhood of that ½ wl frequency.

From your driver spec’s and tolerable box size, there is a combination which looks promising and smaller than you upper limit.

Make one ten cubic foot cabinet for box drivers –or- make two five cubic foot enclosures for one driver each. I say 10 cubic feet with a loose tolerance, 9 to 11 works fine too.

Brace the walls, a thumb rule, no more than about 10 inches of un braced panel (using Baltic birch). There is no need to go crazy or overboard with bracing either but some is required, the larger the panels, the greater the number of braces. Cross bracing to an opposing panel is also very effective.

Be sure to brace the baffle board around the driver mounting, that is where the drivers inertial component is felt. Cover the interior walls of the box with fuzzy but don’t fill it.
Perhaps, one could make towers that “hid behind” the main speakers?

Now, tuning into your room. If you measured the response as is, one finds a somewhat over damped sealed box response with an Fb about 37Hz. This would probably sound pretty good and tight as is with a good sensitivity.
IF these were subjectively too loud or on a separate amplifier (where you could adjust level separately) then one can add say 2 Ohms (use 2X25Watt) in series with each driver. This lowers the overall sensitivity BUT produces a response “knee” more in line with the knee in the room gain slope. Once at the correct level, this alignment will have more deep bass, also if separately driven, one can add an equalizer to help smooth the rooms LF response..

Once you have something you can listen to and measure, you can zero in on the “low pass” xover filter. If you feel or measure that you would like a little more vlf content, then fill the enclosures with fiberglass. That will shift the Fb where the response knee is, downward a bit.

This should get you squarely into the VLF realm, potentially single digits.
Best,
Tom Danley

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Follow Ups Full Thread

Topic - Is Replicating Bass Even Possible In The Average Room? - thetubeguy1954 14:00:42 10/18/10 (31)

RE: Is Replicating Bass Even Possible In The Average Room? - IEaudiodude 06:08:43 11/10/10 (0)

of course - Bruce from DC 16:25:51 11/09/10 (0)

It is but not with OB bass systems - Steyr 07:27:28 10/21/10 (3)

RE: It is but not with OB bass systems - Drew Eckhardt 15:30:22 10/21/10 (0)

RE: It is but not with OB bass systems - Inmate51 07:50:52 10/21/10 (1)

RE: It is but not with OB bass systems - Steyr 07:55:35 10/21/10 (0)

RE: Is Replicating Bass Even Possible In The Average Room? - Inmate51 19:31:05 10/20/10 (0)

As An Observation, Looking at Your Rig - Not With Your Speakers... - Doug Schroeder 07:09:14 10/19/10 (8)

RE: As An Observation, Looking at Your Rig - Not With Your Speakers... - thetubeguy1954 08:33:04 10/19/10 (7)

Well Then, I Guess You Have Heard Bass in Your Room... - Doug Schroeder 14:17:54 10/19/10 (1)

What about bass "quality"? - Robert C. Lang 17:32:34 10/19/10 (0)

RE: As An Observation, Looking at Your Rig - Not With Your Speakers... - tomservo 12:16:31 10/19/10 (3)

I Need More Help To Understand - thetubeguy1954 08:29:42 10/20/10 (2)

RE: I Need More Help To Understand - tomservo 09:45:35 10/20/10 (1)

Thanks Tom. I Have A Couple Of More Questions, Ok? - thetubeguy1954 13:34:03 10/20/10 (0)

consider the headphone - badman 09:12:45 10/19/10 (0)

Yes Tom - morricab 05:02:59 10/19/10 (0)

Sure it is - Bill Way 22:40:07 10/18/10 (0)

Yes!! - henrybasstardo 21:56:51 10/18/10 (0)

The Problem with Small Rooms - Brian A 18:42:06 10/18/10 (0)

Think about what you are asking - Robert Hamel 18:28:04 10/18/10 (0)

Yes you can if you just follow some simple rules. - Mr. Dick Hertz 16:44:59 10/18/10 (3)

That Was Good {nt} - thetubeguy1954 08:37:09 10/19/10 (0)

RE: Yes you can if you just follow some simple rules. - IEaudiodude 16:52:14 10/18/10 (1)

You betcher ass bass like bass! nt - Mr. Dick Hertz 19:43:19 10/18/10 (0)

Another thing to consider is that many of us do not... - DeKay 16:31:44 10/18/10 (1)

Good point..A well placed adjacent room can serve as a bass trap - Robert C. Lang 17:50:20 10/19/10 (0)

I think it depends on how much distortion you find acceptable. - genungo 16:02:13 10/18/10 (0)

RE: Is Replicating Bass Even Possible In The Average Room? - tomservo 14:54:20 10/18/10 (0)

RE: Is Replicating Bass Even Possible In The Average Room? - Iron Knee 14:39:16 10/18/10 (0)

Doubtful........... - kavakidd 14:18:31 10/18/10 (0)

Follow Ups

RE: I Need More Help To Understand - tomservo 09:45:35 10/20/10 (1)

Thanks Tom. I Have A Couple Of More Questions, Ok? - thetubeguy1954 13:34:03 10/20/10 (0)

RE: I Need More Help To Understand

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