Need help choosing a driver and a horn design. - diyAudio
Go Back   Home > Forums > Loudspeakers > Full Range

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 7th February 2009, 07:09 AM   #1
diyAudio Member
 
italynstylion's Avatar
 
Join Date: Feb 2009
Location: Dallas, Tx.
Default Need help choosing a driver and a horn design.

I was looking at building some towers for myself and I have decided to go with a full range horn setup. A friend of mine on DIYMobileAudio.com with me posted about his full range setup and he is very impressed with his.


I'm looking for the best Sq possible. I'm going to be running a pair of subs with these so REALLY low end extension isn't a necessity but I'd like these to be able to hold their own with some lower notes.

Driver selection
I'm currently looking at the Fostex 108ESigma drivers. I know a fair amount about speakers but full range is foreign territory to me so I'm having trouble selecting drivers to build a horn for. Are the 108ESigmas a good choice or is there something else I should be looking at? Also, I've looked around and seen some of the eNabled drivers out there and couldn't really tell if it was worth it or not. Can the eNable process be done to the 108ESigma for some improvement? Planet hifi has the FE127eN for something like 240 and I wasn't sure how much the process really improved them. I know the 108ESigma's aren't that efficient but I'm not running a low powered tube amp or something so that wont be a problem. I looked at the Fostex suggested horn enclosure and I'm going to build that unless there is something else that you guys know about that sounds a ton better. I've looked at a ton of stuff and I don't want something that's TOO monstrous like the spawn variants.


My idea is to have each sub in a sealed enclosure on the ground below the horn enclosure and decouple the horn enclosure by way of a spike system on top of the subwoofer like I have pictured below. Is there any reason why this would be a bad idea? I'm just trying to think ahead here. I'm in uncharted waters and I'm trying to get everything planned out right.


Click the image to open in full size.


Any help offered is appreciated.
  Reply With Quote
Old 7th February 2009, 09:39 AM   #2
diyAudio Member
 
Scottmoose's Avatar
 
Join Date: Mar 2005
Location: UK
WRT drivers, as you seem to be looking at the 4in - 4 1/2in units, the 108 is a lovely unit, but it's somewhat restricted in output terms & it really does prefer quite a big horn (relatively speaking) to really come to life. The 126&127, especially Dave's upgraded versions, are a little (very much, in the latter case) more forgiving. The upgrades are worth it IMO; they're so heavily modified, they no longer sound like the Fostex base unit, but something much more expensive. One of the more recent comments I dug out: http://www.diyaudio.com/forums/showt...16#post1735016

Right, next step[s]. You say you want the 'best' SQ possible; can't say I blame you, don't we all, but you don't say how you define 'best' (it's a bit subjective you know... ), or your circumstances. Firstly, exactly what amplifier are you running? This will have a bearing on which driver / cabinet will suit you best. FR based systems are all about matching the amplifier / driver / cabinet / room interface. You can make things work if needed via Eq, series resistance etc., but it's usually a better idea to pick the most optimal match to your requirements in the first place.

So much for that -taste? What sort of presentation do you like? How loud will you be listening? How far away? Room size? Is it 'live' or 'dead'? Material to be played (some cabinets are specifically designed for certain genres).

OK, on to BLHs. Most of them will not thank you for sitting them on a subwoofer, as they rely on using the floor boundary condition to double their effective mouth area -& if you remove that, the response will suffer. The Fostex designs are patchy. Some are OK, others less so. The 108 box is passable, but not much more than that. For e.g., you'd be better off with an FE126eN in the Frugel-horn (if you can corner-load them) or Ron's A126 (if a rear wall is available). Both are far superior to the Fostex cabinets. The Spawn range generally features larger designs, but there are some smaller boxes there for the 126 & its 127 stablemate, if you root through the plans page. There's even a reasonably compact double horn for the 108.

Whatever you do, don't rush into a decision. Take your time; it'll save you some in the long run. And BTW, if possible, don't build it out of MDF. Not an ideal material for horns.

Best
Scott
  Reply With Quote
Old 7th February 2009, 02:27 PM   #3
diyAudio Member
 
italynstylion's Avatar
 
Join Date: Feb 2009
Location: Dallas, Tx.
Quote:
Originally posted by Scottmoose
WRT drivers, as you seem to be looking at the 4in - 4 1/2in units, the 108 is a lovely unit, but it's somewhat restricted in output terms & it really does prefer quite a big horn (relatively speaking) to really come to life. The 126&127, especially Dave's upgraded versions, are a little (very much, in the latter case) more forgiving. The upgrades are worth it IMO; they're so heavily modified, they no longer sound like the Fostex base unit, but something much more expensive. One of the more recent comments I dug out: http://www.diyaudio.com/forums/showt...16#post1735016

Right, next step[s]. You say you want the 'best' SQ possible; can't say I blame you, don't we all, but you don't say how you define 'best' (it's a bit subjective you know... ), or your circumstances. Firstly, exactly what amplifier are you running? This will have a bearing on which driver / cabinet will suit you best. FR based systems are all about matching the amplifier / driver / cabinet / room interface. You can make things work if needed via Eq, series resistance etc., but it's usually a better idea to pick the most optimal match to your requirements in the first place.

So much for that -taste? What sort of presentation do you like? How loud will you be listening? How far away? Room size? Is it 'live' or 'dead'? Material to be played (some cabinets are specifically designed for certain genres).

OK, on to BLHs. Most of them will not thank you for sitting them on a subwoofer, as they rely on using the floor boundary condition to double their effective mouth area -& if you remove that, the response will suffer. The Fostex designs are patchy. Some are OK, others less so. The 108 box is passable, but not much more than that. For e.g., you'd be better off with an FE126eN in the Frugel-horn (if you can corner-load them) or Ron's A126 (if a rear wall is available). Both are far superior to the Fostex cabinets. The Spawn range generally features larger designs, but there are some smaller boxes there for the 126 & its 127 stablemate, if you root through the plans page. There's even a reasonably compact double horn for the 108.

Whatever you do, don't rush into a decision. Take your time; it'll save you some in the long run. And BTW, if possible, don't build it out of MDF. Not an ideal material for horns.

Best
Scott

For the amplifier I won't be running anything special. I'll be running my Harmon/Kardon AVR147. I don't have much available in the way of Eq but I do have a high pass crossover in the receiver. When I say "best Sq possible" I know that's an impossible task. My taste in drivers this far has been congruent with what Focal offers. Some say they are bright but I rather like the way they sound. Accuracy is much preferred over coloration.

Room size isn't set in stone since I'm likely to move within a few months into an apartment. But, the room size wont be huge. When i actually do listening I listen to mostly jazz. I do really like rock and other stuff to but finding recordings that do a good speaker justice are hard to find.

I thought that the supplied design for the 108 looked a little rough to be honest. What exactly isn't opptimal about it? I was pondering using body filler to round off the areas where multiple pieces of wood are used to create a false curve much like stairs. I was going to smooth out the shape hoping that response would look better after doing so.


My main goal is to find something i will really enjoy sitting down and listening to. I'd rather critique the recording than my speakers.
  Reply With Quote
Old 7th February 2009, 04:27 PM   #4
diyAudio Member
 
Scottmoose's Avatar
 
Join Date: Mar 2005
Location: UK
That's the last thing you should do. The Fostex cabinets, like many of mine, create the flare out of an expanding series of constant CSA pipes. The sharp edges are actually beneficial to / part of this type of enclosure. It's just that in this case, it's not an especially distinguished example -not terrible, but not ideal either; the profile isn't really optimal for the driver, and so on & so forth.

The HK amp is OK, but the small Fostex units won't exactly flatter it, so you'll probably need to look at your cables at least (something resistive like thin magnet wire) to help tweak things.
  Reply With Quote
Old 7th February 2009, 05:01 PM   #5
Henkjan is offline Henkjan  Netherlands
diyAudio Member
 
Henkjan's Avatar
 
Join Date: Jan 2006
Location: Berkel en Rodenrijs
did you notice my thread about the Conical horn I built, using the Markaudio Alpair10 :
Conical Horn with Markaudio Alpair10 FR
  Reply With Quote
Old 7th February 2009, 05:52 PM   #6
diyAudio Member
 
italynstylion's Avatar
 
Join Date: Feb 2009
Location: Dallas, Tx.
Thanks for the heads up. What do you mean by thin magnet wire? I was sort of under the impression that oxygen free copper wire was all pretty much equal as long as the gauge was thick enough to handle the current going through it. What is the difference?


In the future I'd like to get a nice tube amp of some sort but for now the HK is what I have so I'm sticking with it.



I have been doing TONS of searching and I found that there is an eNable kit of some sort that is sold here on the forum. What exactly is done to the drivers in the process? I read that there is some clay like stuff that goes on the motor structure to prevent resonances and the cone is treated too. Is that all or is there more to it? The kit was like $25 and if it is something I could do myself I'd try it for sure.


Basically, I know that the 127 driver that has been eNabled is leaps and bounds better than it's factory sibling. This is why I'm curious if I started with what I perceive to be a better driver out of the box (108) and eNable it, would that yield better results? I hadn't read anything about people treating the 108 driver; is there a reason for that?



I must say, I'm kinda stuck on integrating a sub into the bottom of the system so I can keep things compact in an apartment. It will also keep the sound stage in front. Is there a horn design that would work better with that idea?



PS: In hind sight I realize I should probably have told you all what I'm listening to right now as a sort of bench mark. Currently, I have a 5.2 (yes i made that up) system that is composed of HSU Research HB-1 book shelf speakers with a center channel and a pair of Peerless 830845 12" XXLS Subwoofers in separate sealed enclosures. When listening to music I run only two bookshelves in stereo with the pair of subs. I like it a lot but I'm intrigued by the idea of full range stuff hoping to find that level of detail and accuracy in music I didn't even know existed.
  Reply With Quote
Old 7th February 2009, 05:52 PM   #7
diyAudio Member
 
italynstylion's Avatar
 
Join Date: Feb 2009
Location: Dallas, Tx.
Quote:
Originally posted by Henkjan
did you notice my thread about the Conical horn I built, using the Markaudio Alpair10 :
Conical Horn with Markaudio Alpair10 FR

The design looks MUCH simpler than the one I was planning and it's not all that tall. My conversions to inches put it right about 4 feet off the ground with the driver cone sitting about 3 feet off the ground. Do you think this design decoupled on top of a sub would inhibit it's function? The top of the sub where the horn would be spiked would be about 450mm off the ground.
  Reply With Quote
Old 7th February 2009, 06:16 PM   #8
diyAudio Member
 
Scottmoose's Avatar
 
Join Date: Mar 2005
Location: UK
MathCAD predicted responses of aforementioned cabinet
1/ 1/2 space
2/ 1/4 space, front baffle 1m from rear wall
2/ 1/4 space, front baffle 1m from rear wall, cabinet raised 0.45m

Conclusions: the falling response below ~600Hz in the two lower simulations is concurrent with the baffle-step point. The dip in the mid-upper bass is likely to be floor-bounce. I'd would avoid raising them on top of subwoofers, as I mentioned before, as it does the response no favours at all, and probably favour corner-loading, to try to get as much help from the room as possible, if a compensation circuit is not wanted.
Attached Images
File Type: gif 3.gif (16.9 KB, 219 views)
  Reply With Quote
Old 7th February 2009, 06:26 PM   #9
chops is offline chops  United States
diyAudio Member
 
chops's Avatar
 
Join Date: Apr 2003
Location: Lakeland, Florida
Quote:
Originally posted by italynstylion
Thanks for the heads up. What do you mean by thin magnet wire? I was sort of under the impression that oxygen free copper wire was all pretty much equal as long as the gauge was thick enough to handle the current going through it. What is the difference?


In the future I'd like to get a nice tube amp of some sort but for now the HK is what I have so I'm sticking with it.



I have been doing TONS of searching and I found that there is an eNable kit of some sort that is sold here on the forum. What exactly is done to the drivers in the process? I read that there is some clay like stuff that goes on the motor structure to prevent resonances and the cone is treated too. Is that all or is there more to it? The kit was like $25 and if it is something I could do myself I'd try it for sure.


Basically, I know that the 127 driver that has been eNabled is leaps and bounds better than it's factory sibling. This is why I'm curious if I started with what I perceive to be a better driver out of the box (108) and eNable it, would that yield better results? I hadn't read anything about people treating the 108 driver; is there a reason for that?



I must say, I'm kinda stuck on integrating a sub into the bottom of the system so I can keep things compact in an apartment. It will also keep the sound stage in front. Is there a horn design that would work better with that idea?



PS: In hind sight I realize I should probably have told you all what I'm listening to right now as a sort of bench mark. Currently, I have a 5.2 (yes i made that up) system that is composed of HSU Research HB-1 book shelf speakers with a center channel and a pair of Peerless 830845 12" XXLS Subwoofers in separate sealed enclosures. When listening to music I run only two bookshelves in stereo with the pair of subs. I like it a lot but I'm intrigued by the idea of full range stuff hoping to find that level of detail and accuracy in music I didn't even know existed.
The thinner magnet wire will help raise the impedance the receiver will see, effectively dropping the damping factor of the amp some to help create a little more bass output from the Fostex drivers. That's why a lot of people use tube amps or small digital amps with these drivers... They already have low damping factors to begin with.

Also, something like the FE126eN such as I have will blow your current bookshelves out of the water. Not that I'm bashing your speakers, but I do know what these drivers are capable of and with the speakers I have around here, the modified Fostex drivers are blowing them all away.


Quote:
Originally posted by italynstylion



The design looks MUCH simpler than the one I was planning and it's not all that tall. My conversions to inches put it right about 4 feet off the ground with the driver cone sitting about 3 feet off the ground. Do you think this design decoupled on top of a sub would inhibit it's function? The top of the sub where the horn would be spiked would be about 450mm off the ground.
I think the biggest reason for going with a horn design is to get as much usable bass out of these small drivers as possible. Since you have stereo subs, that may not be an issue for you and can mount the horns on top of your subs and still be perfectly happy.

I have my Fe126eN's in aperiodic loaded cardboard boxes which taper off the bass around 150Hz or so. I have them sitting on top of a pair of 3-way towers I built 13 years ago that use 8" Vifa woofers. I have the rest of the drivers in those enclosures disconnected and am only using the Vifa's for bass support. They are crossed over at 120Hz. They blend perfectly with the little Fostex drivers and you would not believe how incredible this system actually sounds, YES, even in cardboard boxes!

That thread that Scottmoose linked to is my thread about the entire project. I have pondered many horn designs, but have finally settled on a large, very heavy one-off bookshelf design of my own. Feel free to read through that thread. There's a lot of great information in there and you can see where and why I changed my plans with these awesome little drivers.
__________________
Charles
  Reply With Quote
Old 7th February 2009, 10:04 PM   #10
diyAudio Member
 
italynstylion's Avatar
 
Join Date: Feb 2009
Location: Dallas, Tx.
Quote:
Originally posted by Scottmoose
MathCAD predicted responses of aforementioned cabinet
1/ 1/2 space
2/ 1/4 space, front baffle 1m from rear wall
2/ 1/4 space, front baffle 1m from rear wall, cabinet raised 0.45m

Conclusions: the falling response below ~600Hz in the two lower simulations is concurrent with the baffle-step point. The dip in the mid-upper bass is likely to be floor-bounce. I'd would avoid raising them on top of subwoofers, as I mentioned before, as it does the response no favours at all, and probably favour corner-loading, to try to get as much help from the room as possible, if a compensation circuit is not wanted.

Scott, is that for the horn that I posted or is that for the one that Henkjan posted? Thankyou for running the numbers for me. I didn't expect you to do that but it definitely explains what your talking about.


A question about that; if I may...Is the drop in response due to the fact the horn's mouth fires at the listener and parallel to the ground so the ground being farther from the mouth has a drastic effect? That may have been stating the obvious but I just wanted to make sure.

If that was the case it gives me an idea though. In my quest to learn about this stuff I ran across the BIB site. I didn't really understand how to design that style of horn but I noticed that that "style" or horn enclosure has it's mouth on the top of the enclosure. Would this style of horn be adversely affected if I raised it a touch to put on the sub? I wouldn't think it would be impacted as much but I have no way of knowing and that's why I'm asking you!

How is that style of horn designed? Is the FE126eN that Chops mentioned a strong candidate for that type of horn? I found that driver on their site and the response in the BIB looked decent from what I could tell. Again, I'm not looking for much in terms of response below 80hz, I just want detail and realism.

Quote:
Originally posted by chops


The thinner magnet wire will help raise the impedance the receiver will see, effectively dropping the damping factor of the amp some to help create a little more bass output from the Fostex drivers. That's why a lot of people use tube amps or small digital amps with these drivers... They already have low damping factors to begin with.

Also, something like the FE126eN such as I have will blow your current bookshelves out of the water. Not that I'm bashing your speakers, but I do know what these drivers are capable of and with the speakers I have around here, the modified Fostex drivers are blowing them all away.
Interesting, I'll end up getting a different amp sometime so I doubt I'll end up getting any of that wire but if i feel something is lacking I'll check it out. I'm not sure when I'd get a new amp but one day it will happen.


Quote:


I think the biggest reason for going with a horn design is to get as much usable bass out of these small drivers as possible. Since you have stereo subs, that may not be an issue for you and can mount the horns on top of your subs and still be perfectly happy.

I have my Fe126eN's in aperiodic loaded cardboard boxes which taper off the bass around 150Hz or so. I have them sitting on top of a pair of 3-way towers I built 13 years ago that use 8" Vifa woofers. I have the rest of the drivers in those enclosures disconnected and am only using the Vifa's for bass support. They are crossed over at 120Hz. They blend perfectly with the little Fostex drivers and you would not believe how incredible this system actually sounds, YES, even in cardboard boxes!

That thread that Scottmoose linked to is my thread about the entire project. I have pondered many horn designs, but have finally settled on a large, very heavy one-off bookshelf design of my own. Feel free to read through that thread. There's a lot of great information in there and you can see where and why I changed my plans with these awesome little drivers.
The subs I'm using are DIYMA R 12's in sealed enclosures. The R12's will play up to 120hz well but I wasn't planning on running them quite that high.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Choosing Amps for a 5 Way Active Horn System KCCT82 Pass Labs 32 26th April 2009 12:21 AM
choosing specs for driver that will be used for OB c3conv Multi-Way 3 21st November 2008 07:28 AM
Need Help with choosing Nagaoka-Style Horn Monte Verdi Multi-Way 1 28th October 2008 09:37 PM
Choosing Woofers for Horn Enclosures asauer Multi-Way 8 23rd January 2004 05:57 AM
Phase plug for cone driver in mid-bass horn design? mefistofelez Multi-Way 2 18th October 2003 07:59 PM


New To Site? Need Help?

All times are GMT. The time now is 03:40 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2