another confused beginner

Hello everyone!
Yes, I know, another confused beginner!:scratch:
My problem is this: I want to construct a set of bookshelf speakers using the peerless 850122 csx 6.5 inch woofer. My problem lies with enclosure design. I have been reading every book I can find on the subject, including The Loudspeaker Cookbook, and although I know what I want in a speaker and have a few ideas, I really haven't been able to come up with anything concrete.
I listen to a lot of different music, much of which the bass frequencies roll down very low. Now I don't expect miracles from these speakers, but I want decent bass - a nice tight sound, but also decent volume. I just want to know what knowledgable people have to say on the matter. Would bass be seriously subdued in an acoustic suspension system? If I make a sealed box, how can I optimise it for low f3, and yet still retain good transient response and reasonably faithful sound? I have read that the parameter Qtc is critical, but I don't really understand what it is, or how to design a speaker with a certain Qtc.
Maybe a ported box would be best. But are these difficult to get right and achieve good results with? In Loudspeaker cookbook, It says you have to test box resonant frequencies with signal generators and stuff, which is equipment I don't have!!
So as you can see I'm a bit lost. Can anyone help me?!?!? It would be much appreciated!!!
 

SpeakerBob

Member
2002-08-15 6:21 pm
UK
Hello Craig,

Yes bass would be seriously subdued in a sealed box...

download winISD to look at how volume/ vented/sealed etc affect Qtc.

As it happens winISD lists this driver in its default directory

Heres a response plot for sealed (yellow) in a 16L enclosure (Qtc .71) against ported (green) in a 34.2L with a 10.2cm dia port 48.1cm long - tuned to 35.6Hz (Ql .7)

hth

Rob
 

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