Have 4 drivers with 0.97 Qts. What should I make with it?

[krisskross]

I made a horrid ported sound bar 4yrs ago when I was complete newb to the topic. And frankly, I'm still newb.

Now I know little better than 4yrs ago and also not satisfied with the sound it's making, I decided to tear the sound bar and and salvage drivers.

So Now I have 4 drivers of Peerless TC9FD18-08 which has quite extreme Qts: 0.89 (Link)

Now, I would like to make pair of bookshelf out of these 4 drivers. (music oriented. But would be nice to reach 50hz F3)


Any suggestion of what to do with high Qts driver like this?

Am I better off with closed enclosure? Or passive rad?

Would I need subwoofer with crossover?

I've heard that high Qts doesn't mix with ported box.

But I would like to avoid adding complexity such as crossover and want it to be bookshelf size.

Any idea of what to do would be great.

 

[digitalfrost]

If you put them into a 12-13l enclosure with a capacitor in front of 300uF, you will get an f3 of 98hz.

Red is without capacitor.

 

[krisskross]

If you put them into a 12-13l enclosure with a capacitor in front of 300uF, you will get an f3 of 98hz.

View attachment 362452

Red is without capacitor.

I see... I need to look up what that means.
Any suggestions on what type of enclosure to use for this type of driver?

 

[Wolf]

Sealed and stuffed or aperiodic.

 

[ChrisG]

3rd order sealed box, as mentioned above, is a pretty good approach.

The alternative would be to put it in a ported box tuned to around 70Hz (going lower probably won't happen) and EQ the result to flat. Since you have 4x drivers, I'd suggest running one of them wide-open, and using an inductor to roll the HF off the other one. That'll gain you +6dB of output in the LF, which is where you need it.


Without a floorstanding horn enclosure, you're unlikely to get 50Hz out of these. 70Hz can be pretty satisfying, though, especially if there's a bit of a peak before the LF rolloff.


Chris

 

[DVDdoug]

Get some speaker design software and you can predict/model/optimize performance. The software should recommend a box design and you can experiment (virtually) with various sealed & ported designs. I've used WinISD (FREE).

Would I need subwoofer with crossover?

Big things make bass!