March 5, 2011

Waveguide GTG #2


Following on from our previous event, we wanted to investigate compression drivers and waveguides. Previously we heard differences and we also measured them, but we were comparing multiple changes at a time. This meant we couldn't be sure what accounted for the changes. 

There is a thread about this even on StereoNET


Our measurement setup included a laptop with Arta and speaker and mic elevated outdoors. We even used some acoustic treatment to damp the first reflection off a wall (not shown). 

We measured:

1. XT1086 WG + Faital Pro HF10TX
2. XT1086 WG + B&C DE250
3. Dayton 10" WG + B&C DE250
4. Dayton 12" WG + B&C DE250
5. Econowave (JBL Clone) + B&C DE250

XT1086 is a waveguide by 18 Sound. The Dayton 10" and 12" waveguides are a low cost plastic moulded unit.


JBL clone and Dayton 10" and 12" waveguides.


BMS 4550 on the left and Selenium D220Ti.



We had some problems with the wind and with the turntable setup, unfortunately meaning the results are not as accurate as last time.

After measuring outdoors, we set up a range of combinations indoors with Behringer DCX acting as an active crossover. The room was set up with 3 very large bass traps, two of them shown below. Those are 1.2m wide 50mm thick rigid fibreglass sheets with about 300mm of foam behind.


Always some last minute jerry-rigging! We had to drill some holes larger for an adaptor to get the bolt on drivers to work on screw type waveguides. 


Removing DE250 from my Miniwaves:



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