home *** CD-ROM | disk | FTP | other *** search
-
-
- Box Plot For Windows 3.0
-
- By Rick Carlson
- Sparta Sound Co.
-
- Copyright (c) 1990,1991, by Sparta Sound Co.
- ALL RIGHTS RESERVED
-
-
- !!!!!!!!!!!!!!! UNREGISTERED SHAREWARE VERSION 1.4 !!!!!!!!!!!!!!!!!
- PLEASE REGISTER
-
- ****************************************************************************
- *** Boxplot is distributed as Shareware. It is NOT a free Program. ***
- *** If you use Boxplot then you should register it. ***
- ****************************************************************************
-
- COPYRIGHT NOTICE
-
- BOXPLOT is Copyright (c) 1990,1991 by Sparta Sound Co.
- This document is Copyright (c) 1990,1991 by Sparta Sound Co.
-
-
- Registered Boxplot users will recieve the latest version of
- BOXPLOT which includes added features such as "system tuning" and
- box dimensioning, as well as complete documentation and many more
- speaker files from various popular manufacturers. Included in
- the documentation is a tutorial on Loudspeaker enclosure design,
- construction, and tuning. Registered users will also recieve mail
- notification of major new releases of BOXPLOT.
-
- If you are new to speaker building then I strongly recommend the
- tutorial. Nothing is worse than spending many hours building a
- speaker enclosure only to be disapointed because of lack of
- proper construction and tuning.
-
- ==========================================================================
-
- To register please send $25.00 to
- Rick Carlson
- 62 Fox Trail Rd.
- Sparta, NJ 07871
- USA
-
- Compuserve 71041,3015
-
- See the README.DOC file for more information
-
- *****************************************************************************
-
- Introduction
-
- Box Plot is a Microsoft Windows based program that calculates the
- frequency response and maximum Sound pressure level for a sealed
- or vented loudspeaker enclosure.
-
- Boxplot is based on the Sealed or Vented box system. While there
- are many other types of enclosures for loudspeaker systems
- (Horns, Infinite baffle, Transmission lines), the Vented enclosure is
- currently the most popular type among speaker manufacturers and audiophiles.
- It is also one of the easier types to build correctly.
-
- This Version of Box Plot requires Microsoft Windows 3.0 or later
- to run. A math coprocessor is not required but greatly speeds
- up the frequency response calculations.
-
- This program can be used by audio hobbyist or professional to
- design and modify high quality loudspeaker enclosures. You
- should be familiar with the Thiele/Small loudspeaker parameters
- in order to best utilize this program, but all that is required
- is a basic understanding of vented loudspeakers and a good data
- sheet for your drivers. I strongly recommend the tutorial for
- beginners.
-
-
- Operation:
-
- This Program was designed to allow 'almost' real time update of
- the response plot as box parameters are changed.This is usefull
- when trying to shoehorn a speaker into a non optimum box. Many
- different combinations of box parameters can be tried in a short
- period of time. If Auto Plot is turned on, then clicking on the
- OK button of the BOX Parameters dialog box will replot the
- response curves. Autoplot can be turned off, for slower machines.
-
-
- Speaker Parameters:
-
- Speaker parameters are entered by bringing up the a dialog box
- under Speaker, on the main menu. When you ar satisfied with your
- changes, click on the OK button to save the parameters. The
- parameter names are the Thiele/Small parameters specified on most
- good spec sheets. Parameters can be entered in either metric or
- english units. Selecting the meteric or english checkbox will
- change the entire programs units not just the speaker parameters.
-
- Fs Free air resonance of the speaker.
- Vas Volume of air equivalent to the speakers compliance.
- Qms Mechanical Q of the speaker.
- Qes Electrical Q of the speaker.
- Xmax Maximum linear cone displacement.
- Pd Maximum power dissipation (in watts).
- Re Dc resistance of the voice coil.
- Diam Effective piston diameter of speaker.
-
-
- Box Parameters:
-
- Box Parameters are entered in a dialog box. When the OK
- button is clicked the Box Parameters dialog box stays on the
- screen. To close the dialog box click on the Close button or
- use the system drop down menu (upper left of dialog box) to
- close the box. The reason the dialog box stays on screen is
- to make it easier to edit parameters and see the effect on
- frequency response.
-
- There are 6 types of boxes that can be modeled with Box Plot.
- Closed Box:
- Simple sealed Enclosure.
- Closed Box with first order equalizer:
- Sealed box with first order hi pass filter. The first order
- filter usually provides subsonic attenuation.
- Closed Box with second order filter:
- Sealed box with a second order hi pass filter. The filter
- is usually an active filter placed before the power amp.
- Adjusting the Q of this filter modifies the low end response
- of the system. This is usually used to extend the lower
- 3dB point.
- Vented Box:
- Box with a tuned port.
- Vented Box with first order eq:
- First order Eq is more usefull here than is a sealed box.
- Because it will limit cone excursion at subsonic frequencies.
- Vented Box with second order eq:
- Same as sealed box.
-
- Box Parameters:
- Alpha: System Compliance ratio.
- Alpha is the ratio of box volume (Vb) to speaker Vas.
- Alpha = Vas / Vb
- Alpha tells you how big to make the box.
-
- H: System tuning ratio.
- H is the ratio of the speaker free air resonance to
- the system tuning frequency (Fsb).
- H = Fs/Fsb
- This determines how to design the vent.
-
- Ql: Q from leakage losses.
- This is the enclosure Q at Fb resuting from leakage loss.
- (better boxes have higher Q's. This parameter must be measured
- after the enclosure is built. Start with 7 as a good estimate.
-
- Fe/Fs:
- This is the ratio of the Equalizer resonant frequency to
- the box frequency.
- D
- This is the equalizer Damping coiefficent. D = 1/Q
-
-
- Comments:
- The comments field is a text string, 255 chars long that
- can be used to annotate the graph.
-
- Vent Design:
- This box will show the vent length based on the present
- box/ speaker combination. The Air Speed mach number is the
- vent air speed relative to the speed of sound. The air speed
- should be kept below .2-.3 in order for wind noise from the
- vent to be inaudiable.
-
- Auto Plot:
- When the Auto Plot menu item is checked, anytime a speaker
- or box parameter is changed, the graph will be regenerated.
- This keeps the graph up to date with the latest parameters.
- This also may be annoying on slower machines so it can be
- turned off.
-
- File:
- New:
- This will reset all parameters to some predefined settings.
- The settings are based on nothing at all, just some numbers
- that wont do real wierd things. (The speaker parameters are
- from a well known manufacturer.)
-
- Save:
- Save as:
- This will save the speaker, box, and comments in the specified
- file.
-
- Open:
- Read a file on the disk. The default file extension is .SPK
- but has no real significance.
-
- Print:
- This will print the response curves as shown on the screen
- along with the speaker and box parameters.
-
- Printer Setup:
- This will bring up the active printer setup box. Any changes
- made in the setup box will be saved as the current printer
- setup.
-
-
- To register Please send $15.00 to
- Rick Carlson
- 62 Fox Trail Rd
- Sparta, NJ. 07871
-
- Compuserve 71041,3015
-
- I will send out a disk with the latest version of BOXPLOT,
- the complete documentation, and the Speaker tutorial.
- Registered users will recieve notification of program updates.
-
- If you have suggestions, comments, bug reports or just feel
- like writing please do so.
-
- Let me know what other kinds of programs would be usefull to
- the audiophile.
-
-
-