[noviygera]

Hi,
Need some feedback on your experience with OB?
I am changing my system:
http://picasaweb.google.ru/noviygera/BasementSystem/photo#5129998603582849282

to open baffle mids crossed over at about 200 Hz to the OB subs.

I have a Fostex FE206e (low Qtc) that I am can use on the OB in an MTM config so I would need to buy another pair of them. I have DBX digital eq/crossover for the rolloff compensation.
How would higher Q vintage (saba, altec) or pro drivers with less eq copmare in terms of sound?
Looking for ideas and suggestions to utilize what drivers I have already or change to better different one for better sound.
Thanks,
Herman

[mcgsxr]

Welcome to AC, and welcome to the OB Circle!

Nice, another basement guy!  I have been leveraging mine for sound for years, and now with the recent addition of a pool table, am happy with the functionality - it is still unfinished, so it looks like crap, but I don't care that much.

As for your Q's, I am comfortable suggesting higher Q vintage or pro drivers for sub use, but am not sure about your Fostex - are you considering running them on OB, or continuing to use them in the ported boxes?

If on OB, I see they have low QTS, but other than bass, I am not sure that matters that much.

As long as you are sure to keep low frequencies out of them, to avoid blowing them, I would think that well worth exploring.

[noviygera]

My subs are finished. I will be running the Fostex FE206E on OB 200Hz and up. I have digital eq. However, i need High SPL. So perhaps MTM layout. Or maybe even 3 Fostex mids per side. Suggestions?
I need a balance of SPL and SQ!

Herman

[zobsky]

Not sure OB is the best solution for high SPL . How much SPL do you need? the fostex 206E  is reasonably sensitive at over 95 dB/W/m . Haven't tried this, but you might consider a quick experiment horn loading the front of the fostex 206E (build a crude conical horn) and leaving the rear open ie. a combination horn / OB . Hopefully, it won't honk.

Another option if you're running out of xmax with the 206E could be to build a U-baffle . The stuffing in the rear will help damp cone motion, to an extent.

Arraying or MTM'ing the 206E could possibly work, but might not be the best idea, if you intend to run them full range (interference nasties).

[D OB G]

Hi noviygera,

The Fostex, with its very low Q, has a rising response as you know, meaing that it isn't up to the claimed 95 dB, down low at 200 Hz.
However, even with equalization, the excurtion required at 200 Hz is probably visually imperceptible and is not going to reach x-max.
The whole point with the Fostex is to try to attain a point source, so an MTM doesn't sound like a good idea to me.
In fact, I have used a single FE206e in exactly this way (to OB bass) with extremely disappointing results.
It seems to all depend on what type of music you like.
The driver can only handle very simple music, eg single vocal, very small acoustic group.
If you listen to anything more demanding, I would suggest that you can do better than the Fostex, and certainly forget anything like clasical music.

David

[Graham Maynard]

I used a B200 in D'Appolito dipole between two 8" mid-bass to good effect.

My next version will be B200 between two BG20, with separate bass below, as a dipole column.

Cheers ..... Graham.

[scorpion]

Graham,

Why intimidate B200 with two BG20s ? 

/Erling

[Graham Maynard]

To compensate for narrow baffle step and lower B200 efficiency below 1kHz without filtering main drive to the B200.
Also helps to improve the overall radiation pattern.

http://server6.theimagehosting.com/image.php?img=B200plus.jpg

Ckick on image for larger size.


Cheers ........ Graham.

[scorpion]

Yes, I see !

Using BG20s fullrange too ?

/Erling

[Graham Maynard]

These were Peerless, which have similar efficiency to the Visatons up to 1kHz.
Wired in parallel and out with a series choke around 500Hz, with overlap making crossover level into to the B200 efficiency.

Much nicer sounding than solo B200 with its raising HF.

Peerless have greater Xmax, but not enough cone area for OB.

Cheers ...... Graham.