Home Theater Forum and Systems banner
1 - 5 of 5 Posts

·
Registered
Joined
·
10 Posts
Discussion Starter · #1 ·
Hi All

A bit of background. I am a part time muso and electronics guy who spends most of his spare time working on stuff for the band, home recording, building amps etc and chanced on this site whilst looking for some software like REW!

I have a 2.1 system that gets used occasionally when time allows. I have a sub on loan for the system but it sounds boomy despite the phase setting and I am suspecting as one option that there could be a phase reversal in the wiring of one of the bookshelf speakers.

I am about to load REW up to a laptop so I can do a check in the living room on the system but I am not sure what I should be looking for in the graphs REW is going to give me.

Any pointers would be great.

thanks
Derek
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #4 ·
Re: Phase Tests - Polarity issues

Thanks for the quick feedback.

Well I guess it is all terminology but a speaker that is 180 deg out of phase would have polarity reversal, which is what I was getting at.

So if my bookshelves have been wired up internally incorrectly so say one of the drivers is connected reverse polarity I would get some weird results by my guessing.

I like the idea of taking measurements then reversing polarity and retesting, that certainly would give some data to base a factual repsonse on.

I was hoping to avoid pulling the speakers down and looking inside.

I have tried three different brand subs in differing locations and get pretty similar results to the ear so I was starting to look for a more complex answer to the question.

thanks
Derek
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #11 · (Edited)
Hi, and thanks to all for the replies and great ideas

The bookshelves are quite old Goodman 1010's and the orginal sub was a wharfedale 15 now replaced with a front firing 12 in a smaller box, not sure of the branding, also had a smaller front firing 8 in there from my studio set up to try.

The Goodmans had the low freq drivers changed at some point in their long lives. Hence my suspicion on their wiring. I will start with the battery test, thanks for that suggestion, then move on to REW if that doesn't show an issue.

The setting on the sub is what I would call "subtle" ie not lots of volume and roll of at a mid point setting. Phase switch set so that it sounds the best to my ear, ie the less boomy setting. This set up is in a reasonable size lounge room, carpet floors, lots of soft furnishings, drapes on the windows etc.

I have done some measurements with REW in my studio to get acquainted with the software some time ago but I don't have it on the laptop just yet. Too many other interruptions like family, work etc getting in the way of the project. I guess this project also will allow me to get better trained in how it works and what I am seeing.

My original technical education is as a professional engineer in the radio frequency communications space but I haven't played with these toys for a long long time.

Oh and the sub is fed from the tape out section of the receiver!

regards
Derek
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #12 ·
Ok, here is the latest ...

set up rew and looked at left and right channels. Found one of the bookshelves giving poor results on spectrum test.

Replaced both bookshelves with some home made ones that I know are ok and voila, very listenable.

Big thanks to all

regards
Derek
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #14 ·
Hi

Got one pulled down at the moment, it did have polarity reversed. Also found the tweeter is poling so needs a major fix, will pull the other one down also when I get a minute.

Importantly though my mate and I had a lot of fun using REW in the living room, he is a real home theather junkie and having only scratched the surface of its features it might become a bit contagious.!!

thanks
Derek
 
1 - 5 of 5 Posts
Top