Best 4 inch driver for open baffle help ?

[bigaudioscotto]

I am trying to decide on an appropriate driver
for open baffle 4 inch, I will mate these with
a pair of alpha 15a in H frame,I am running
diy paradise Charlize amp,I will use this on
the FR drivers and I will use a plate amp on the
bass units,I am thinking it will need to be one of the fostex units.
I just can't decide which one to go with,I also looked at
CSS EL70 but I don't think I have enough power to drive those.
any help is greatly appreciated.

[Trapshooter]

I'm not sure how helpful my post will be other than to say I like the EL70's I have in my 14.5l CB. For OB you'll need units with decent x-max which for their size the EL70's certainly have, correct? I haven't decided on what their permanent enclosure will be. I don't think OB's will be it due to there size. I'm curious, how large are your baffles?

[bigaudioscotto]

Originally Posted by Trapshooter

I'm not sure how helpful my post will be other than to say I like the EL70's I have in my 14.5l CB. For OB you'll need units with decent x-max which for their size the EL70's certainly have, correct? I haven't decided on what their permanent enclosure will be. I don't think OB's will be it due to there size. I'm curious, how large are your baffles?

The baffles will be 22 wide 40 high,I am just not sure if I have
enough power to push EL70's,I have about 15 watts a side
if you are fimiliar with Charlize amp,what are you using to drive yours.
EL70 Is a nice looking unit.
Scott

[planet10]

Your lack of power will push you towards a higher efficiency unit, but the Alpair 7, EL70, and CHR70 from Mark Audio are all really good 4". Martin King used the FE103 on his passive baffle, with bi-amping you are not as limited. FE127, 126 would work, as do FF85 and FE83 (they are 3").

Do also remember that in terms of dynamics, biamping increases the effective power of your amplifiers, and that people are happy using 3.5-10W with the more efficient Mark Audios FR. If your loudness levels are not too demanding your Charlize may well have sufficient oomf (edit: 15w should be more than adequate for any of these ... the MA are all 4 ohm, vrs the 8 ohm of the Fostex -- that is 3 dB of amp power right there)

dave

[bigaudioscotto]

Originally Posted by planet10

Your lack of power will push you towards a higher efficiency unit, but the Alpair 7, EL70, and CHR70 from Mark Audio are all really good 4". Martin King used the FE103 on his passive baffle, with bi-amping you are not as limited. FE127, 126 would work, as do FF85 and FE83 (they are 3").

Do also remember that in terms of dynamics, biamping increases the effective power of your amplifiers, and that people are happy using 3.5-10W with the more efficient Mark Audios FR. If your loudness levels are not too demanding your Charlize may well have sufficient oomf (edit: 15w should be more than adequate for any of these ... the MA are all 4 ohm, vrs the 8 ohm of the Fostex -- that is 3 dB of amp power right there)

dave

Dave
I am not sure Charlize can safely run 4 ohm do you have any idea on that.

[planet10]

Originally Posted by bigaudioscotto

Dave
I am not sure Charlize can run 4 ohm do you have any idea on that.

Tripath amps are usually happier with 4 ohms and optimized for such. Here is the chart from Yeo's site (i expect scanned from the TriPath tech notes)



About 12W into 4 and 6.5W into 8 before distortion starts its skyward reach... 15W & 8W at 0.1%, 17 & 9.5 at 1% and about 22 & 13 at the oft used 10% distortion levels.

I don't think you need to worry too much about power. As well the character of this amp is better suited to the EL70 than any of the Fostex.

dave

[bigaudioscotto]

Originally Posted by planet10

Tripath amps are usually happier with 4 ohms and optimized for such. Here is the chart from Yeo's site (i expect scanned from the TriPath tech notes)



About 12W into 4 and 6.5W into 8 before distortion starts its skyward reach... 15W & 8W at 0.1%, 17 & 9.5 at 1% and about 22 & 13 at the oft used 10% distortion levels.

I don't think you need to worry too much about power. As well the character of this amp is better suited to the EL70 than any of the Fostex.

dave

Dave
Man you are on top of it, so you are thinking EL70 would be
best fit of Mark Audio stuff is that right.
by the way I sent you a email earlier thinking you could help
so nevermind that email.
Scott,

[dave w p]

If you can find a pair, the original Jordan Watts drivers would fit the bill. If not one of the new ones will suffice. They have astonishing detail and are full range units, but will improve with a sub.
The HIFI site

[DaveCan]

[QUOTE=bigaudioscotto;2242658]I am trying to decide on an appropriate driver
for open baffle 4 inch, I will mate these with
a pair of alpha 15a in H frame


I'm not so sure of H-Frames used up into the vocal range mated with a full range driver on OB is a good thing. The H-Frame used as bass support in the under 80 hz region is very nice.. I would suggest using the Alpha on a flat baffle with sides behind rather than boxing in around the front wave of the driver as done in an H-Frame.. So a U frame of sorts I would guess.. In the H-Frame the driver is basically recessed with the depth of the box sides walling off the front wave of the driver, which to me smears the sound at the higher x-over levels...

I used the Goldwood 18'' driver in a flat open baffle as a test while awaiting to start on my H-Frames ,and it sounded nice up into the 100hz + region, however installed into the H-Frames with the 7'' or so of depth wrapped around the front of the driver, the sound was quite colored up over 80-90hz and very nice as a sub at 70 or so hz.. Very clean and natural bass tone with the x-over kept low..

I know that the H-Frame Jordon combo has a following and I'm not trying to take away from that, just relating the sound to me in my situation with a half OB half BIB set up using the 4'' driver pure and unfiltered in the BIB cabs ..

Next will be the Goldwoods on a flat u frame type baffle and the little Fostex drivers filtered , but that's a long ways off..

Good luck and enjoy.. The Goldwoods are also a good deal if you want to move up a bit in size or can etc.. BTW I love my 18'' Goldwood sub duty H-Frames even as placed near the wall.. The opening to the hall is`what lets me cheat the more usual placement and sounds really nice in here too


Sorry to all if the pic went too big, it was small then??? ''Shrug''

[chrisb]

DaveCan:

looks great - a big improvement over the BIB's, or just an experiment?

does the floor really droop that much?

dave w p:

have you experienced any of the latest Mark Audio drivers? They are in at least the same league as the current Jordans, and certainly surpass the original JW modules of 40 or so yrs ago;




oh dear, I'm gonna pay for that