Leaving OB - something big, vented and high SPL instead

[fakamada]

Hi guys.

I'm seriously thinking about leaving OB bass. I have Selenium 15PW3 (QTS 0.6) in small baffle. 50cmx100cm with 40cm slated wings.

In my opinion it lacks resolution. I want to try low QTS drivers (QTS 0.25-0.35) but don't have space for large-enough baffles.

I'm thinking to get some low QTS 12" or 15" and put it into ported enclosure. It has to have large diameter of port because I don't want too much port and box coloration.

This leads us to large enclosures. Max volume that I can fit into my room (25sq.meters) is 160 liters and the only place for it right in front of the wall.

One way is onken enclosure and the other is plain BR.

Don't know yet about port tuning. There are two ways to go.

standard: 40-50hz to get flat response
very low: 20-25hzto get rid of port coloration.

In both cases i'd like the port to have at least 80% of speakers diameter.

I also need high SPL (96db/w is optimal) to match my vintage set Saba drivers.


Any of you guys tried this kind of concepts ? Any input ?

For now I was thinking about Emi Delta 12A maybe smth from Jesen (higher fs, qts but very light cones)

[Pano]

Well I went from an OB rig with the same Selenium driver to a modified Altec VOTT box and Altec drivers. The box is a LOT more work to get sounding right, but I feel it's worth it. Unfortunately it's a big box - circa 310 liters.

But you can do smaller with good results. Though the big Onken is still big. I do like the sound of the Onken/Ultraflex box.

Will do interesting to know what you find that will work well in the 160L size.

[fakamada]

welll 160l is called Onken-Petite.

Delta 12A seems perfect. On the other hand it's 400w is too much for my every day SPL levels.

Supravox 285 is perfect but very expensive..

[fakamada]

Originally Posted by panomaniac

The box is a LOT more work to get sounding right, but I feel it's worth it.

That's why i'm also thinking about BR but based on Onken idea. Big with large diameter port. Same thinking but easy to tune at low cost.

How did you find Selenium on OB ? Did you also have issues with low bass speed/resolution ?

[InclinedPlane]

Huh. That Selenium driver in OB should have some of the highest bass resolution available. I went through a similar problem and discovered that the problem was the amplifier. I paid 700 for a custom upgrade and now it's great. DON'T use subwoofer plate amps unless you rebuild them or have someone do it for you. They are the ultimate in tubby and boom.

I will never go back to boxed speakers. OB is that good. But it requires careful design work and there are many people here that could help you. It would help if you described the specifics of your gripe.

[fakamada]

I'm driving them with Rotel RA-980BX wuth very high DF (>1000). I'ts known of it's bass control abilities...
But it's second handed and might been repaired. I have to check it out.

[fakamada]

As for plate amp I have a VERY good source of DIY high quality amps. I'm not susre if it's possible to integrate subwoofer with OB.

[Pano]

I did not have any resolution problems with the Selenium driver. There was some peaking, tho. Going to a better amp did tighten up the bass, for sure. High damping factor and good power supply really help.

The problems for me were getting the crossover right - a big learning curve - and getting it to play below Fs.

I still like the open baffle sound very much, but with a big, low pressure box I find I get the same type sound, more low end and much better efficiency. But the trade offs are the big box and getting the tuning right.

BTW, I have heard the big Onken, the Petit Onken and the Mini-Onken (Focal 10") I liked them all very much. But the bigger they were, the more I liked them.

[fakamada]

Originally Posted by InclinedPlane

I paid 700 for a custom upgrade and now it's great.

Did you go back to Pyle's ? Or stay with Jensen's ?

Originally Posted by panomaniac

But the bigger they were, the more I liked them.