[guest60106]

I have been looking at several drivers for midbass/lower-midrange application for an OB design I am working on and this driver looks nice other than the price which I feel is a bit high but not out of the question. I like the fact that it is paper and has a very open basket and small magnet structure. I think the specs look pretty good for the range I want to use it for. I am looking to use it from around 80Hz to about 1000 Hz driven with about 200 watts. What do you guys think?

http://meniscusaudio.com/images/H1411.pdf






Not sure of long term availability because I can’t find it on the Seas site but it seems to be available from Madisound.

[Davey]

That driver will narrow quite a bit when you get up into the 1000hz range.   You are aware of that?
Or is your plan to couple to a midrange driver and then ultimately to a tweeter?

Cheers,

Dave.

[guest60106]

That driver will narrow quite a bit when you get up into the 1000hz range.   You are aware of that?
Or is your plan to couple to a midrange driver and then ultimately to a tweeter?

Cheers,

Dave.

My plan at this point is to cross it to a smaller midrange around 800-1000 Hz

Matthew

[Nate Hansen]

The spider and basket structure that supports it pretty much makes the magnet size a moot point here.......

[guest60106]

The spider and basket structure that supports it pretty much makes the magnet size a moot point here.......

Agreed. It still has a fairly open basket though.

[scorpion]

Depending on baffle size (width mainly) there will be a baffle hump you have to deal with in the range 300 - 800 hz. 80 hz will be around 3 dB down from the 100-200 range I think.
And it will be hard to get 100 dB at 80 hz without reaching X-max for your proposed element.

Why not go - 300 hz bass then mid and treble: much easier to handle. OB bass will go down to about 30 Hz with the proper element. Going deeper will need special care.

/Erling

[JBspeakerman]

This Seas 10" is as state of the art a driver as ever there where!   Excellent as a power OB mid.  Good to around 275 HZ on a 24" class baffle width and 6" wing depth.  Mates oh so well with any of the
Seas TDF series tweeters... Assuming of course the OB bass section is less than 93 DBW efficient.  Don't let the simplicity of this classic driver fool you.  It has it all for a bargain price and is SO easy to use.

John

[JBspeakerman]

Also .... forget about the Beaming crap.  So, So over rated.  If you mate it with a proper tweeter at the natural 2.7K roll off point you will be fine.  It will out image the best of what ever you put up against it.  You have to remember the TDF what ever will contribute down to 1,300 or so.  No worries.  Just don't over think things.  Too many theorititians.... not so many actual builders here. 
Sorry I come off as jaded, but after over 50 years of doing this I have a lot more respect for those who try and fail vs those who pontificate!  Hope I got the spelling on that last word correct!

Do and learn.  That is what we are here for!!!


John

[Davey]

Wow. 

Whether you believe even power response is an important factor in speaker design is debatable, but beaming is not "crap."  It's an easily understood acoustic characteristic of a driver based on diameter and frequency reproduced.  A well-designed dipole baffle could actually widen the native response of a driver.....but only up to a point.  At a 2.7khz crossover frequency a normal tweeter will be fairly wide and a ten inch driver very narrow.  An abrupt change in polar response in that area is unavoidable.

It matters not whether you've built one speaker project or a hundred.  Certain rules always apply.

Cheers,

Dave.

[opnly bafld]

Also .... forget about the Beaming crap.  So, So over rated.  If you mate it with a proper tweeter at the natural 2.7K roll off point you will be fine.  It will out image the best of what ever you put up against it.  You have to remember the TDF what ever will contribute down to 1,300 or so.  No worries.  Just don't over think things.  Too many theorititians.... not so many actual builders here. 
Sorry I come off as jaded, but after over 50 years of doing this I have a lot more respect for those who try and fail vs those who pontificate!  Hope I got the spelling on that last word correct!

Do and learn.  That is what we are here for!!!


John

 

Thanks John!

[lowtech]

Whether you believe even power response is an important factor in speaker design is debatable, but beaming is not "crap."

Not entirely true.

It's only a factor if you your head isn't burred in the ground.

[JBspeakerman]

Hello again...

More thoughts on the Seas 10".  The point of my post was not to dispute the laws of physics relative to beaming effects ALL drivers exhibit.  These effects are a factor to be sure and must be accounted for in the overall design.  BTW, the Seas is effectively FLAT at 30 degrees of axis at 2,500 HZ.  Excellent cone and dust cap profiles account for most of this along with a flat on axis acoustical response.

One other thing to keep in mind is the fill in - depth effects realized from rear radiation - rear wall reflection(s) for an open baffle midrange.  Some here may have listened to my "Widow Maker" design demonstrated at LSAF in 2010.  The excellent and uniform power response provided by the Seas 10" surprised many.  In a small hotel room none the less!  Excellent depth and imaging plus the dynamics and power handling of a large area midrange.  A very simple 4 element band pass crossover was a bonus.

Experimentation -  measurement - listening trials indicated the small amount off axis roll off (mainly apparent at greater than 60 degrees at the upper crossover point) were a very small compromise when other design goals and advantages were considered.  Those advantages were, but not limited to a VERY flat on axis acoustic response extending over 3.5 octaves, having enough displacement to play effortlessly at under 150 Hz, excellent over all power handling - output capability, natural 2nd order roll off both on and off axis, crossover simplicity, true 90 dbw operating efficiency (plus another 2.5 db band pass gain) and low distortion throughout the band pass even at 100 plus DB output levels.  You just can't do all of that with anything less than a 8".  I have found a good 10" is a nice compromise.  A 12" such as the Beta 12A is more dynamic, but requires near heroic crossover efforts to tame several issues, including "beaming".  BTW, the Beta is one of my fave drivers!

And finally, the 10" mates so well (harmonically) with the large paper cone 12"-18" woofers commonly used in OB designs.  Plus most practical baffle - woofer dimensions lead to woofer to mid crossover point between 150 - 350 Hz.  The 10" has the area and clean X-Max to get the job done down there.  With an OB mid range, as well as the woofer, all things equal, there is no replacement for clean displacement!

[studiotech]

I like the choice of driver as it seems well suited for the application, just not for the whole range you are proposing.  There's a good reason both Linkwitz and John K have morphed to 4 way designs.  To get everything to jive together better a lower and upper mid are usually necessary.  Granted, I "cheat" on mine too, but at least the Neo10 are narrow so they are really only cheating in the vertical direction and I've got the tweeter off to the side, not above.

Greg

[guest60106]

I like the choice of driver as it seems well suited for the application, just not for the whole range you are proposing.  There's a good reason both Linkwitz and John K have morphed to 4 way designs.  To get everything to jive together better a lower and upper mid are usually necessary.  Granted, I "cheat" on mine too, but at least the Neo10 are narrow so they are really only cheating in the vertical direction and I've got the tweeter off to the side, not above.

Greg

Again, the plan at this point is to use it as a MIDBASS/LOWER MIDRANGE driver. I have 4 10s I am using now for bass on a 27’ x 35” baffle which I am quite happy with. One of the design changes I am considering for the next revision is to utilize an 8” of 10” driver for midbass/lower midrange and cross it to a smaller midrange then to a tweeter and making it a 4-way. This Seas driver looked very attractive to me because of the relatively light paper cone (for a 10) and the specs which is why I posted this thread. Not sure if I will go this way I will go as I am considering other design changes as well. The first thing I need to do is take measurements. I just acquired the software and equipment to do this. I would like to have that done within the next month or so.

The original design can be seen here:http://www.audiocircle.com/index.php?topic=112067.0

Matthew

[panomaniac]

One of the design changes I am considering for the next revision is to utilize an 8” of 10” driver for midbass/lower midrange and cross it to a smaller midrange then to a tweeter and making it a 4-way.

Why?  As a design challenge or exploration? That is understandable.  I can't really see it otherwise when a driver like the 10" Seas mates so well with woofers and tweeters. (Yes, I've heard it).  The Eminence Beta 8 also mates well and is easy to crossover.  Very good driver thru the midrange.  Gary Pimm uses it in his 3-way OB rig.

[JohnR]

HarvyLogan, I'd forgotten that you had the DPL-10s. And a Seas Coax? It seems to me that a 3-way main baffle with the Seas 10" and the coax as the "main" (front) baffle, and the DPL-10s in separate baffles would make everybody happy. I think I would be.

[guest60106]

Why?  As a design challenge or exploration? That is understandable.

Exactly. I have a pair of Beta 8s that I have had for many years and never used. I have considered them. If i went that rout I could probubly scrap the H653 Coax and go straight from the Beta 8 to a tweeter. Deffinatly worth considering. Probubly much better resolution in the midrange as well.

[guest60106]

HarvyLogan, I'd forgotten that you had the DPL-10s. And a Seas Coax? It seems to me that a 3-way main baffle with the Seas 10" and the coax as the "main" (front) baffle, and the DPL-10s in separate baffles would make everybody happy. I think I would be.

Yes John, it is an H653. It sounds pretty good. However, one of my main design constraints for this project is to design an OB that is complete (frequncy wise) on one baffle. I just want 2 speakers in the room. One right and one left. No subs or anthing else. There will deffinatly be some tradeoffs with that constraint but that is part of the challenge. I have a good handle on the bass so far. I just put up a bunch of  traps in the room and they changed the equasion considerably. I have some other changes I am working on as well. For me the trick is to make one change at a time. This project will be ongoing for quite some time. It has to this point been quite a learning curve and very satisfying. Speaker placement is VERY important with what I have so far. I cant wait to take some measurments. The only real thing holding me back on that is my 3 year old James. He has to be into everything that I am doing (which I love) but the equipment is a bit sensitive to a 3 year old's curiosity so I have to find a time when he is busy with other things.

[Davey]

JB,

Thanks.  Much more informative than your previous posting.  When I see comments like "forget about that beaming crap" it makes me wonder just what the objective is for an open-baffle system.

The OB system has two primary advantages over the "conventional" approach......no boxes so internal reverberation can not "color" the driver sound.......and the potential for a directional response that is largely frequency independent.

Looking at the wide variety of OB projects on the various audio forums, I suspect most folks are interested in the former and not the latter.  (Or, they don't know how to achieve the latter.)
It's unfortunate because the superior OB directional behavior is where most of the benefits are.

Harvy has noted that in his project the Seas driver will be used as an midbass/lower-midrange driver with another driver between it and the tweeter.  That appears to be an excellent concept, but since the driver range will be limited, I suspect the success of result will be much more related to the baffle architecture rather than any inherent driver performance.

Cheers,

Dave.

[JBspeakerman]

Just for fun I will be posting some Holm measurements taken by Pano Maniac in my hotel demo room the last day of 2010 LSAF.  This 1st one is a full range plot taken at the listening couch position.  I would estimate about 10' or so from the speaker.  The large hump at around 32 Hz is a room resonance mode.  The dip just below 200 Hz is a suspected floor bounce issue.  The droop from 2K to 5K is partially intentional (BBC dip) and partly due to the Seas 10" dropping off axis response.  This droop provided the best balanced sound from the hard parallel hotel room cement walls.  In larger rooms I would extend the Seas TDFC tweeters response down an extra half octave to retain a better balance.  Nearly all the acoustic energy heard at a 10' listening distance is direct from the front of the drivers.  If you can get 12' or father away the rear wall bounce reaching the listener starts to really increase.   Most of the increase in the lower mid range coming from the rear of Seas 10".  It's not easy to get a flat response from such a large speaker system in a small room.  Low ceilings make things that much more difficult.  I was surprised the WM measured as well as it did given the operating environment.   Pano and many others commented the power response and tonal balance were very good.  As good or better than other excellent offerings there.