horn vs. BS

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A newbie here. Anyone familiar with Audio Nirvana full range drivers and there applications. They seem pretty adamant abnout the whole horn vs. bass relex thing. Am about to embark on my first speaker building project. Was headed down Fostex horn way when I came across Audio Nirvana single driver bass reflex designs. I have no doubt ther are a wide vasrietiy od opines ou there. Keep in mind I am not an electrical or acoustic engineer. "Just the facts ma'am".:eek:
 
Well, they'll sort of work in a BR box. But generally not very well. Sorry, but IMO, comonsenseaudio use anything but. Drivers like that just are not suited to reflex loading, whatever they claim -and do you see any frequency response measurements of completed speakers on their site? No? I don't either. Without going too technical, the drivers don't have the suspension travel, and their magnet is far too powerful for effectively loading in a reflex box. The practical upshot of this is that the response starts to dramatically rise (i.e the get louder and louder) as frequency increases. The cabinet designs in themselves also appear of dubious merit -I'd expect the response to start rolling off around 150Hz, with a big peak at cut-off due to the port tuning / mistuning. Not a great idea IMO.

The drivers themselves aren't too bad, from what I gather at any rate. Not as good as the Fostex units (you get what you pay for in this life), but not terrible either.

Depends how big a box you can go, and what you favour. If you want a simple floorstander, I'd advise you to use my friend Martin King's MLTL project with the FE207E. You'll find the details here: http://www.quarter-wave.com/Project05/Project05.html I've bult 4 pairs of these, and can vouch for their effectiveness.

If you can live with a bigger box, then dropping the FE206E into a horn is always a good plan. The standard cabinet is passable, but you can be sneaky here: the drivers will also work very well in the FE208ESigma cabinet. If you want something a little more challenging to build, Ron Clarke's DallasII is a superb design.
 
If seen a few folks cross various forums who struggle with or write off entirely the fullrange approach because they built a Common Sense Audio recommended enclosure. Some people do like that sound; it is ultra-detailed. Other folks call that ultra-bright. I'm in the latter camp. If you want to give it a shot, feel free. If you don't like the results, just don't write off the fullrange approach until you've tried something more orthadox.

If you want a simple enclosure, use the Fostex FE207E (not FE206E) (or my fav, Hemp Acoustics FR8) in a bass reflex. Add some baffle step compensation while you're at it. The 207 in Martin King's MLTL would be even better.

I don't think (I could be misremembering) any of the Common Sense Audio drivers work in any BR, but you could consider building a proper horn for them. You may also consider heading the direction many of us have and building up a pair of BIB's for your choosen drivers. If you are willing to do a more complex build, you can't go wrong with the horns Scottmoose recommends.

pj
 
Hi hulkster62.

You may find answers here.
http://www.diyaudio.com/forums/showthread/t-61017.html

Funny thing about speaker building. Not many will admit to building a bad one. But it is still better to get opinions from those who have heard what you have in mind.
Better still, see if you can hear a set for yourself. You know what you like, and how much you want to spend.

As you said, you are new to this, and just want the facts. The comment about large magnets and Bass Reflex needs explanation. That's something you can look into as you learn more. All I'll say about that now is that Tannoy, Goodmans, (early) Wharfedale, Altec Lansing, EV, JBL, just to name a few, have different ideas.

For what it's worth, I like the AN supers - on paper. I haven't heard them yet. The cloth surround being a big plus. Seems to outlive foam and rubber.

Geoff
 
Er, I thought I had explained in my post:

their magnet is far too powerful for effectively loading in a reflex box. The practical upshot of this is that the response starts to dramatically rise (i.e the get louder and louder) as frequency increases.

I'm all in favour of extended bass-shelf alignments when they are done well. In fact, that's probably what I'd do with the Audio Nirvana 10in unit (kudos to them for giving the world a new 10in FR driver -about time we had one again). But they need to be large, and can be tricky to get working well with FR units.
 
OK, I had a few minutes.

Swiping the approximate dimensions for the 2.5 cabinet from the commonsenseaudio site, and modifying them a little bit, I slapped the AN 10in driver into it, placed the driver and port as I normally would (as I don't know their location in the originals anyway), and sized the port following my usual proceedure. Result is attached. As I usually do, the LF is rolled off to compensate for room-gain. If you want ~ max flat, use a 2in long vent instead. To roll it off still more, use a 6in vent. However, I reckon the driver will still need either a notch filter, a zobel, or toe-ing in to kill the rise in the midrange. As the cabinet is fairly wide, I suspect that no BSC network will be needed, especially if positioned near a rear wall.

For reference the internal dimensions of the cabinet simmed are:
37in tall
13.5in wide
10.5in deep
7in Zdriver
33in Zport. Port is 3in diameter, 4in long.
0.25lbs ft^3 stuffing from the top 15in down.

Should work pretty nicely & have plenty of grunt down low. Impedence is mild, so amplifier load should be pretty easy, and port velocity is low, so there should be no problems with port noise.
 

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Thank you ALL for the info. My original plan was to build a 206 horn and it would seem maybe I was heading in the right direction without really knowing it. I was going to build the Fostex recomended cab. I should add that I am a carpenter/woodworker w/ my own small shop. Building cabinets is not a huge challenge. I should also add that I have purchased the materials to build the 206's. Materials minus the drivers, that is. These will be taking up a large portion of my small living room. I also have the fortune of not living with someone who may find my taste in audio equipment appalling on anyone of a number of levels. Yes, there is something to be thankful for everyday.
With the small amount of material that is going to be left over I am thinking of a project with the Fostex 103's. I have only come across the one horn design for these. Is anyone familiar with any designs other than the fostex recomended?
I am quite sure I have many more questions but that will do for now.
Again thank you all and happy holidays!
 
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