OB, High Sensitivity, Loudspeaker questions

[AudioGeek]

ok, so as many of you might now, my current system is an Alpha 15a for bass and a fostex fe167e for everything else.

bass is according to the design that MJK designed. Thanks!

my problem is that i do not really like the fe167e handling everything.

I also want to add a second 15" to increase the sensitivity somewhat.

probably up to 96 instead of the 90 with the Alpha15a after the OB roll-of takes it away.

sooo... i am looking for a driver that will work with 2 Alpha15a in an OB that is "better" than the fe167e.

I do not mind adding a tweeter to it.

I guess i am looking for a driver that will handle 90% of the music. 400-?

thinking like beta 12lt or visaton b200 or supravox ($$$$$).

low THD, smooth response, great power handling.

thank you in advance for any help.

[DaveCan]

This could be a good candidate with a tweeter.
http://www.madisound.com/catalog/pro...roducts_id=275

Here's a project with the 208esig http://www.blackdahlia.com/html/tip_43.html Dave

[jamikl]

Hi Audiogeek. I am looking at PHL 6.5" and 10" for similar purpose. These are around 96dB for the smaller one and 100Db for the 10I. I will probably need a ribbon above this. Somebody in Tasmania, Australia, was advertising ribbons with I think 99dB sensitivity a few days ago but I can"t find the thread!!!

Some of the PHL can be hornloaded as well.
jamikl

[AudioGeek]

well how about the Radian 5208C or the Audax PR170M0 ?

the Radian is a co-axial which seems to have good reviews. the Audax is a 100db midrange but looks like it has some nasty break-up modes (dunno if audible).

Still OB, High eff, low THD etc is goal.

Thanks for your choices so far. PHL is kinda expensive.... but so is the Radian i guess.

[AudioGeek]

Yeah i guess those PHL look good, but they look awfully close to the Audax.

gotta go to work. bbl.

[Godzilla]

Hi, i have a similar setup to you... Alpha 15's in H-Frames and a Fostex 165k in BIBs... playing with super tweeters to cap things off so i can move onto another project...

I have been thinking along the same lines as you looking for an efficient OB driver to match up with the Alpha 15's. The Eminence Lil Buddy looks interesting. I found out about it by searching threads.

http://www.guitarcenter.com/Eminence...ource=4WWRWXGB

Looks just right for OB and certainly as efficient as you're going to get.

I have heard the Audax in OB and it sounds great but not sure it's much more efficient (if at all) than the Fostex driver you want to replace. Plus, it doesn't go as low and has a ragged top end. Too much crossover work for me i think.

My system is in a 'cobbled together' state right now but i do love the sound i get and can spend two hours at a time listening without fatigue. Amazing!

http://www.diyaudio.com/forums/attac...amp=1233604947

Yes, the Alpha 15's in H-Frames sound great! Perfect for a home system. There are probably many excellent ways to top them off but hi eff - wide range drivers seem to be the most satisfying for me after all these years of searching/listening/futzing.

I bet your Fostex 167e sounded great until you paired them with the Alpha 15's (love how you can simply stack them as an upgrade - so simple and doens't take any more floor space)... They really are great bass makers. MJK uses Lowther drivers. Perhaps that's the best way to go... but a bit expensive. I'd look to Eminence again. Even some of their newer 8" drivers look amazing, but not really for OB. Seems a touch of pro audio drivers properly tamed could provide amazing sound in the home.

Godzilla

[ultrachrome]

The few MJK designs I've looked at typically have a crossover <400Hz.

Based on my limited understanding and John Kreskovsky's ABC Dipole worksheet, if you raise your crossover point you'll ultimately be limiting your woofer's LF output. With a higher Fc, you need to make your woofer baffle smaller to ensure their dipole peak stays above that frequency.

The result is the need for more EQ resulting in your woofer reaching xmax at a higher frequency.

You can mitigate this somewhat with additional woofers.

A quick look suggests that the difference in LF output between a 150 and 400Hz crossover is 10dB.

[ultrachrome]

Originally posted by AudioGeek
well how about the Radian 5208C or the Audax PR170M0 ?

the Radian is a co-axial which seems to have good reviews. the Audax is a 100db midrange but looks like it has some nasty break-up modes (dunno if audible).

Still OB, High eff, low THD etc is goal.

Thanks for your choices so far. PHL is kinda expensive.... but so is the Radian i guess.

PHL has a higher xmax which gives you more design flexibility. So does B&C 6MD38.

I just restarted a long dormant dipole project using the PR170M0. I should get my mic back from calibration in a few days. I intend to determine the useful upper limits of this woofer.

[AudioGeek]

well to be clear... i want to use 2 Alpha 15a's. this should raise the efficiency from 90 to 96 maybe.

90 is taking into account the OB roll-of etc... similar to the MJK plans.

Also, on the plans he has lower x-over set at 200 and upper at 400.

sooo... looking for a mid with 95-96db sensitivity and wide flat range. has to do OB of course.

i will look at the B&C also.

the Radian looks promising.

[tinitus]

I suggest to build a pushpull ripole

I have had Beyma SM118N in mind

Though, it would be a sub only and need active plateamp

Fore midbass you still have plenty power with your Alpha-15

Your Fostex may benefit from removing whizzer cone, but then a tweeter might be needed, but crossed very high any cheap ribbon/planar will do