Hi,
My first post but I've been reading these forums for a while. I have a question regarding my amp and speaker matching.
I have a Poineer VSX-52TX receiver which can be set to 8ohms or 6ohms (8ohms preferably according to the manual). I just got the B&W DM 620 for a good deal and they sound great. Some online specs say they are 8 ohms, some 4 ohms. I measured it and apparently I got the 4 ohms speakers.
According to this article audioholics.com/education/frequently-asked-questions/connecting-4-ohm-speakers-to-an-8-ohm-receiver-or-amplifier (cant post links yet) its OK as long as I watch the volume and the receivers ventilation. Other posts say 4 ohm speakers with a 8 ohm amp is not recommended, other also say just to watch the levels.
I'm also running 4 Bose Model 100 for surround and surround back. They are rated 4-8 ohms. I measured them as 4 ohms. My centerchannel is from the polk audio RM 6700 series which is 8 ohms.
Right now I have my amp set at 8 ohms and keeping it at reasonable levels. Is this OK? I'm a causing any damage? Should I set the amp to 6 ohms for better power handling?
Besides replacing the amp or speakers, is there another solution to properly match the impedances? Is there a cheaper version of something like this: zeroimpedance.com/box.html?
Any advise or tips are highly appreciated.
Thanks
Oliver
A few things. First you can't measure speaker impedance with an ohm meter. With an Ohm meter you measure DC resistance. Impedance has to be measured dynamically and varies with frequency.
Your speakers are specified at 4 ohms on the B & W archive.
Most speakers are in fact four ohm these days, no matter what the manufacturer says.
You speakers are quite an old design. They use an 8" speaker with passive radiator. Sensitivity is high, so you should not have to push your receiver hard.
Now your speakers have an F3 point of 58 Hz, so they don't have a very good bass performance. Also with passive radiators bass usually falls away quicker than with standard ports, and the driver decouples from the box faster, leading to excess cone travel and damage. The max power for those speakers is 100 watts., and I would bet a lot less in the bass.
I'm more concerned about you damaging the speakers, with modern powers available, particularly with that type of design. If you are using a sub, I would recommend a small speaker setting and crossover no lower than 100 Hz. Those speakers are before the days of Hi-Fi speakers reproducing Hollywood's whiz bangs. Also those speakers were aimed at the classical music lover rather than heavy metal.
