Speaker Phasing?

Ross Bryon · Post by **Ross Bryon** » Tue Oct 21, 2003 7:14 am

A number of mgs on this list have mentioned - in relation to replacing
speakers... "make sure the phasing is correct".
But I've seen no explanation of just what "phasing" is... or how to
make sur it is correct.
As I'm about to embark on a speaker replacement exercise, can someone
explain please?

Ross Bryon
Ampersand Design
ross@ampersand.co.nz
BRG V-Spec 1991 Roadster

Grant · Post by **Grant** » Tue Oct 21, 2003 7:54 am

Phasing of the speakers ensures the connections to all speakers are the
right way round. That is, all speakers are connected so that when a positive
voltage is connected to the positive terminal with respect to the negative
terminal of the speakers, the cones all move in the same direction. This is
most noticeable on the bass frequencies.
To check the connections, get a 1.5 volt battery and a couple of leads.
Connect the negative of the battery to the negative terminal on the speaker,
then connect the positive of the battery briefly to the positive terminal of
the speaker. Note which way the cone moves. Now confirm the cones of all the
other speakers move in the same direction when the battery is connected. If
the speaker terminals are not marked or the markings are missing, use this
method to determine which terminal is which.
When checking the headrest speakers, make sure the two speakers are not
connected to each other. Mine were completely wrong with the positive of one
speaker connected to the negative lead that was supposed to go to the other
speaker etc.!
If you have a stereo system in the house, try placing the speakers facing
each other but about 600mm apart, then have a listen to the music. Now
reverse the connections to one of the speakers and you will hear the loss of
bass frequencies.

Grant.

Pete Bronlund · Post by **Pete Bronlund** » Tue Oct 21, 2003 12:25 pm

Phaseing speakers has alot to do whether you receive a proper stereo image, ie the
music surrounds you with the lead singer center stage. If out of phase, parts of
the music will sound weak as if there's a hole in the stereo image.

Ross Bryon · Post by **Ross Bryon** » Tue Oct 21, 2003 7:07 pm

Thanks... now understand and have checked all my 6 new speakers as I
installed them.
Also found the differing connectors a help (wide vx narrow spade
receptacles) but found the headrest speakers wired backwards for
left/right balance. Will fix them later if it bothers me.
Thanks again for the cogent explanation.

Ross.

On Tuesday, October 21, 2003, at 07:54 AM, The Simpsons wrote:

[...]

Bill Rehm · Post by **Bill Rehm** » Tue Oct 21, 2003 7:13 pm

Ross
after all you the diligent work you have invested on your what I believe is
a 91 BRG I suspect I would love to exchange yours for mine (or at least
have you consult to me on upgrading mine so I have something to look
forwartd to )

))

Regards
Bill

Gram · Post by **Gram** » Tue Oct 21, 2003 7:16 pm

I fitted high quality speakers in my headrests but to be honest I find them
annoying and they detract from the stereo image so I never use them. If you
have high quality door speakers (I took zorrunos advice and went to Jaycar,
they do some excellent titanium coned speakers for a very reasonable price),
they should give you the right db level and stereo image. Putting speakers
in the headrest spoils the sound stage. Another excellent thing to do is to
fit 'bass shakers' in the seats, these give you the impression of having a
big subwoofer (they thump you in the back and under the seat) but vibrate
without emitting any audible sound. If you are prepared to spend a bit of
time and money you can actually get some very good sound from the MX5 even
with the top down (and mine is up as often as Chic's, probably less). In
case anyone is interested in 'bass shakers', Jaycar still have the budget
ones (aural activators) at less than $30 a pair - I have one of these
underneath each seat and a larger alpine behind - same ones fitted to the
BMW Z3's.

Gram
D4NGER

Ross Bryon · Post by **Ross Bryon** » Tue Oct 21, 2003 7:33 pm

Sorry Bill, no trade. (As Gollum says... it mine... all MINE... my
PRECIOUSsssss!)

But seriously, there is so much more to do before I get it to where I
want it. Presently I'm concentrating on the cheaper bits that I can do
piecemeal. Someday I'll have to tackle all the little bodywork dings
and resulting repaint... (shudder!)

In the meantime, I'm really enjoying the top-down weather -- though I
think anything less than a solid downpour is "top-down weather" - even
showers are bearable if you don't have to stop too long at lights!

;>)

Ross

Bill Rehm · Post by **Bill Rehm** » Tue Oct 21, 2003 8:03 pm

Mate I love your passion for your puddle jumper --- you are without a doubt a real MX5er!!! Others talk the talk YOU sir walk it!

Regards
Bill

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