speaker driver size

[gobblyguk]

Hi folks.

I've been checking out these forums the past month and getting a great education. I am presently building a home theatre room in my basement (13x17x8 ) and I have a fundamental question I'm hoping someone can answer.

I am presently searching for a 5.1 speaker system and wonder what minimum size low frequency driver my fronts/centre should have. I know the LF cutoff for these will be prob 80hz so a large driver is not needed, however will a larger driver be required to give me that impressive dynamic experience which I understand depends on moving a lot of air. Hope this is clear.

I've been looking at bookshelf speakers for the fronts which have 6"-7" drivers, namely Paradigm Studio 20's and JMLabs Cobalt 806S, will these be plenty loud and dynamic if powered properly? The Cobalts are really a step above the Paradigms I feel in overall sound quality and especially detail in side-by-side comparison, and in price also, but the Cobalts are rated at only 75W max which seems low, whereas the Studios are rated at 120W I think. Is 75W too low or does JMLabs rate their speakers low? I will be sitting about 13 feet back from the front/centre channels.

The best system I've yet heard was setup with 8" Genelecs in a 7.1 with dual Genelec 12" subs with a Rotel 1068 Pre/Processor, it provided the absolute best detail I've ever heard as well as incredible dynamic ability. That detail with a large projected image draws you in like nothing I have seen before or since. The cost of this system was prohibitive, but I really want to get as much of that detail as possible in my passive system. I looked at putting together a powered system with Mackie 604's and a used Rotel Pre/Pro for the same money I budgetted for my passive system but the LF drivers are again only 6" and I hear the 604's are not near the same as the 804's from Mackie. Do you think I need to move up in driver size for the front/centre or is 6"-7" fine. Also, any reason why there is so little discussion about powered systems in home theatre and for a 5.1 system and this room size would you go with the dipoles of Paradigm Studio line or direct radiating speakers of the Cobalt line?

Sorry for so many questions but I can only afford to do this once and really want to get it right!

[David Meek]

Hi James, welcome to The Guide. :welcome:

I see you've done a bit of research and auditioning before taking the plunge. Good man! That's the best way to avoid disappointments.

Don't get too hung up on the power ratings of speakers. The Cobalts will be safe to use with any decent-to-awesome amplification at any "sensible" listening volume. If you like the sound of them over the Studios, then let that be your guide. If you are going with matched monitor-type speakers, you'll have difficulty finding anything that'll go down past 50-55 Hz. Oh, the Cobalts are rated to 50 Hz - cool. If you are concerned about the lower registers then you'll need to add a sub to the mix, but to begin with, 50 Hz and up will get you most of the sonics you need to enjoy a movie. Having said that, a sub will absolutely increase your enjoyment and immersion in a movie - especially if you are an action/war/sci-fi lover.

With your room size, you don't need a set of Rockport Hyperions to fill it with sound. The Cobalts or Studio 20s will work just fine. No worries there. Generally, when talking about "pressurizing" a room it is more in conjunction with low bass from a sub which is a function of driver size, excursion, etc.

I can't really comment on the powered-speaker issue as I don't have any ears-on knowledge. Good luck and keep us posted, okay?

[gobblyguk]

Thanks

Thanks for the quick response David. . I figured these drivers would be fine to fill the space but wanted reassurance from someone with experience. I do plan on buying a sub with this system. From what I have read it seems I'll buy the Hsu VTF-3 and be done with it. Seems like a no brainer in the $1000 subwoofer budget arena, although it looks really big! Thanks again.