Vented / Open baffle hybrid design and ideas

[Spike415]

Hello everyone. I have just joined this forum after lurking for a while, and have had a dab at building my own speakers in the past. These however are for myself.

I am looking at producing a pair of speakers which are a 3-way. They will use the following drivers:

CSS SDX7

Scan-Speak 15W/4424G00

Scan Speak D2606/920000

Now because my room is fairly small, i can have a large gap behind the back of the speaker itself (about30-45cm) but i like the idea of open baffle speakers and mucking around with a set of car speakers before (QTs = 0.85) on a baffle it sounded nice, but off course a lack of bass. I have spent many hours on likwitz website, reading about them and the orions they have.

This is where i got my hybrid idea. The SDX7 would be used to produce the lower freqencies, and then crossover to the scan-speak woofer as early as possible. Then finall to the tweeter.

First thing really is, can you see any big problems with this concept?
I have thought of the following

1) having 2 tweeters facing away from each other
2) using a passive radiator with the SDX7 and fit it on the back of the vented enclosure

Any ideas and thoughts would be appreciated. Just want to see if any of your lovely guys and gals can see issues i will get with this idea.

Thanks in advance

Paul


Edit 1 - I realise the scan-speak woofer has a very low qts, and i also know most open baffle speakers use a high qts, but will this effect it if im crossing the frequency over at a higher level?

 

[ra7]

A high Qts mid unit should be fine as long as you cross it over higher than say 150 Hz.

For an OB design, I would advise for bigger woofers - both mid and bass. That's the route to scary dynamics in my opinion.

Have you looked at Martin King's website? Great place to start your OB project.

Quarter Wavelength Loudspeaker Design

 

[Spike415]

Thanks for your reply.

So with the mid-range woofer, im looking for high Qts drivers which will fit. max size i can really use is a 6 or 7" woofer. otherwise they just won't fit where they are intended. Was looking at some of the mark audio drivers.

Has anyone got some good reccomendations for a OB driver. Possibly a dayton?

Thanks in advance

paul