AMP for these speakers....

[Howard]

Rave, I didn't say that impedance was the sensitivity, I used the word "sensitive" in context to explain what impedance meant... And then you just re-iterated what I said


Butuz knows his stuff And yeah car subwoofer systems have crazy impedances... Some as low as 1 or 2 Ohms!!

Glad we could be of help Praetorian. Enjoy your new equipment

[Butuz]

Originally posted by praetorian
@Butuz: The guy that gave me this advice was right but I had it the wrong way round so it was totally my fault to start off He runs his own professional sound and lighting rig company and has been for the past 5 years doing massive events for some high profile customers. It was most definately me that had the correct intention but had the information completely and utterly the wrong way round /me slaps self silly

hehehe thats an easy mistake to make. Im glad your pro friend is actually a pro and not a pc world employee

Anyway with regards to the amp, the cambridge ones are good for the cash. Got 9 of them in work (A1's if i remember, cheap as chips) to drive speakers for our presentation board things, they do a fine job.

Myself, ive got a Marrantz PM4000 the older version of the current PM4100. That was £150 odd i think too, its super for the money, makes nice sounds come out of my B&W DM601's. Ive a small bedroom so i havent gone crazy on HIFI for that room......yet

I would say probably the cheaper ones are all pretty good but i would go for low end marrantz, nad, rotel - theyre all great for the cash. Cambridge are a bit lower down on the ladder IMO, but still good, and cheaper generally than the above 3.

Just make sure you avoid the box pushing makes like pioneer, panasonic, sony, technics, etc. I'm not saying they dont make good stuff, but generally most of it is mass produced average'ness.

Butuz

[5lab]

actually butuz the marantz is up to 4400 now

[Butuz]

Bah! Pardon me for trying to help!

Butuz

[Rave]

Originally posted by Butuz
Hes right! Impedance basically is the internal reistance of the speakers coil,

Yes....

so the lower the internal resistance the easier they are for the amp to drive.

No, that's just not true. A cheap amp with weedy capacitors in the power supply will have real difficulty driving a low impedance speaker, because it simply won't be able to flow enough current. It's easier for an amp like that to provide a high voltage and a lower current to a higher impedance speaker.

So 16ohm speakers are harder to drive at any given amp wattage than 8 ohm ones wich in turn are harder to drive than 4 ohm speakers. Ever wondered why all the bad boy subwoofers in the back of max power all had crazy watages? Coz theyre all 4 ohm speakers, easy to drive, so the manufacturers rate them as higher watt speakers than 8ohm ones would be.

No, they have crazy wattages because people just look at the numbers and think the bigger the better. The actual numbers would not stand up to scrutiny. There's a good reason why car speakers are all 4 Ohm, it's because the amp has to be powered from a 12V car battery. Consequently, the amp can't supply a voltage higher than 12V without a step up transformer which would add a lot of size and cost; so to get plenty of power through the speaker they run with 4 Ohm impedance. That's not a concern with a mains powered amp.

And also the Sensitivity (db) plays a big part in this too as the lower the sensitivity, the harder the speakers are to drive which means that speakers with a Sensitivity (db) of under 90 make the amp work harder for any given volume than speakers that are 90 or over.

True, but speakers with a sensitivity of 90dB/W+ are pretty hard to make without using horns or making compromises to the frequency response. Your guitar amp for example doesn't really need to go below about (guessing here) 100Hz because that's the frequency of the E string.

Rich :¬)