An E2 inspired loudspeaker: Quick but not dirty

I have not decided if I will use two woofers per box yet like the JBL 4435 or a vertical array like the 1200fe box 4313B posted.

I need to do some room response models and some measurements to try and assess the true room gain below 100 hertz for this system.

At the end of the day if I need to provide for example - 3 db of downward equalisation contour below 100 hertz due to room gain for a relatively smooth bass curve (with the box near the rear wall) this will mean a reduction in cone excursion limts and distortion.

By way of example I recall hearing Bo's 4345 that had been setup nicely and the bass for not exagerated but was smooth and articulate.

Obviously the E2 with dual woofers was an all out effort for massive dynamic range but common sense prevails in terms of the room size and what will give the best overall results.

Horn crafting.

I always wonfered how to create the horn flare and machine i wood.

Here is one way used by a professional in HK

Not as simple as it looks and the process is long to final assembly.

Lots of noise and saw dust too.

Finding the maple ply might not be so easy either.

I will explore this because making the jig is they key.

Ian

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Originally Posted by Ian Mackenzie

Horn crafting.

I always wonfered how to create the horn flare and machine i wood.

Here is one way used by a professional in HK

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Hello Ian,

I have thought about the same issue and a solid chunk of timber is nice, but requires the sort of specialised jigs you show or CNC machining.

Another possibility, if you can find one large enough, is to use a large wooden bowl perhaps 700-1000mm in diameter and cut it into quarters. OK- you don't have a great say in the profile, but the constuction is much simpler as you just need to glue on straight sides for a 90degree flare. Then to make the whole thing "like a rock" fill the dished top and bottom with filler/timber whatever- even polyconcrete.

PS: I'm still looking for the bowl:D- in the meantime I thought I might settle on a large commercial horn flare (pref. in Australia)....looking looking...

Best
JA

http://audioheritage.org/vbulletin/s...ad.php?t=14933

http://www.audioheritage.org/vbullet...62&postcount=9

Thanks for the links.

I think it prudent to try a few different horn types of commerical origin before spending much effort on a diy horn for the JBL 2435.

If I can get some sense out of DDS I will try one of those and one of the Peavy Quadratic horns and maybe a Le Leach flare.

The plan is to try a CD and a asymmetric horn and evaluate them if possible.

It seems to me that it takes like a panel beater to get a usable response with the Bi Radials and the lesser PT wave guides while shearing off valuable sensitivity.

I mean I have seen smoother on axis unequalised response curves out to 16 khertz on other types of horns with no fall off below 1000 hertz and claims by users they image beautifully and have enormous stage depth. Makes you wonder what all the CD fuss is about. I guess recording engineers who chose Tad monitors worldwide for the past couple of decade can't be entirely stupid.

http://www.geocities.jp/arai401204/Horn/A290/A290.html

The question is CD really worth it?

Perhaps for some people but not for everyone.

I suspect the large majority have not heard a really good horn system because of the way commercial realities impact on consumer products that are shall we say affordable and have good WAF.

Like most things there is no free lunch. Its come down to what is more important to the individual.

The Quadratc horn paper provides a very good plain language outline of the why's and wherefore's of various horn types. The Bi radials are far from perfect and I suspect what JBL now uses in their consumer gear is far from what they started out with.

On the diy front there seems to be more or should I say simply better horns (diy horns) around based on the 2 inch throats so I may also try a 1.5 to 2 inch adapter in the absense of an actual consumer JBL clone and see what happens. There are also some excellent 1 inch diy wood horn designs suitable for 1000- 1200 hertz crossover points.

To date the 9800 and the other JBL consumer horn? appears the only worthwhile JBL horns I have seen apart from the 2532.

Although the fact that Mr Widget appears to dislike the 9800 horn suggests spending weeks making a horn out of wood might be better spent on a Tad horn design or a variant thereof.

As I have stated from the outset the horn is the key and really good horns are few and far between and very very expensive.

Ian

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Originally Posted by Ian Mackenzie

... so I may also try a 1.5 to 2 inch adapter ...

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Think it over as it will give more directivity at the upper limit of the driver-horn combination.
__________
Peter

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Originally Posted by Joe Alesi

Hello Ian,

I have thought about the same issue and a solid chunk of timber is nice, but requires the sort of specialised jigs you show or CNC machining.

Another possibility, if you can find one large enough, is to use a large wooden bowl perhaps 700-1000mm in diameter and cut it into quarters. OK- you don't have a great say in the profile, but the constuction is much simpler as you just need to glue on straight sides for a 90degree flare. Then to make the whole thing "like a rock" fill the dished top and bottom with filler/timber whatever- even polyconcrete.

PS: I'm still looking for the bowl:D- in the meantime I thought I might settle on a large commercial horn flare (pref. in Australia)....looking looking...

Best
JA

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Hi Joe,

I dont think its a difficult as it appears.

There are other approaches as well:

http://www.geocities.jp/arai401204/Horn/A290/A290.html

http://www.geocities.jp/arai401204/H.../A290-S90.html

This would make a nice project over our summer.

I imagine that its a case of finding a commercial shop or a retired wood turner / crafter will all the tools in his shed and let him loose.

I would be happy to offer the right person locally serious money because it really is a messy business and there is a lot of room for mistakes as in this is not a weekend job.


Ian

Quote:

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Originally Posted by Hoerninger

Think it over as it will give more directivity at the upper limit of the driver-horn combination.
__________
Peter

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Peter , I appreciate you thoughts.

At this stage its about choices and really trying some different approachs in the practical sense.

Nothing has to be perfect at this point.

People who get uptight and close their eyes at the early stages sometimes miss an opportunity and end up listening to sheer crap for their entire lives.

I wont be trying to shoe horn if you will excuse the pun the end result based on what I might have right now as far a drivers goes.

That was in certain respects the situation with May and its still going.

As you know the 2435 is in effect a throatless affair. Any form of exponential or hyperbolic throat is going to effect directivity but there is more to it than meets the eye. The 2435 reponse above 10 khertz is not text book anyway so that may not be so important.

As things progress if I need to I can turn a customised throat adapter on lathe or if it proves necessary just buy a pair of 2 inch drivers to suit the horn I like.

In so far as the whole directivity thing is concerned its overblown from the earlier days of the PA horn directvity thing imho not well understood in the application of audio in the home.

Forget about horn speakers for a moment.

I have a set of very good 2 way Dynaudio speakers. The tweeter has nice power response.

I have a nice pair two way near field monitors. The tweeter has a wave guide with a dual concentric lenses on the diapgragm that very much restricts the HF dispersion pattern from 2-3 khertz up.

I would be guessing but the angle is in the vacinity of 90 degress or less and narrows coverage at the highest frequencies further.

There is simply no comparison in terms of imaging with the latter, its far superior.

What is interesting is the Dynaudio images best (but poorly) when only slighty toed in.

The nearfield monitors (used at 2 metres) work superbly when toed in almost on axis.

So the notion of wide dispersion and loudspeakers that flank front on into the home listening space might be an old accepted idea but not one that was well understood.

From what I have read broardly and I am no expert if in fact you want a system that images then the interactions in terms of reflections above 1000 hertz with the room become very important. Restricting the coverage angle and toe in of the loudspeaker in towards the listener then makes a lot of sense unless you are prepared to spend a fortune on room treatments and end up with a very technical room aeshetic. Earl Geddes has discussed this at length but people not get it because they are so swayed by convention. Limited information is described in some of the K2 manuals .

There is no rocket science in any of this but the devil is in the details.

Ian

Enough Talk,

The ultimate plan is to obtain a Tad 1601a woofer and run it with the 2435 Be using either of these horns then obtain a 2nd pair of 1601a like the TSM-1: I think that will qualify for an E2 inspired loudspeaker.

The project will span the next 6 months while the horns and enclosures are fabricated.

http://www.geocities.jp/arai401204/H.../A290-S90.html

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Originally Posted by Ian Mackenzie

I came across Lorantz when doing broad search for suitable woofers. Michail Brarabasz the MD of Lortanz responded to an email for information and advised he can spec make a woofer to Tad or better of his own design as a result of demand from the local market and is planning to provide a suitable CNC wood horn.

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Sorry to come in so late but I actually tried to get a job with Lorantz when I first graduated in the early 90's.

They are what I would call "...The Quiet Achievers"

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Originally Posted by Andyoz

Sorry to come in so late but I actually tried to get a job with Lorantz when I first graduated in the early 90's.

They are what I would call "...The Quiet Achievers"

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I cannot comment further other than I was advised ultimately that I was up for about $2000 in start up costs to replicate a Tad driver.:blah:

My guess is that if they figured they could make something that did not break it qualified as being better!:biting:

If money was no object I woud fly Rich out here as as Head of Fabrication between cold showers....LOL

Hello Ian

Another possibility- not sure if you have already mentioned/seen these:

http://cgi.ebay.com.au/ws/eBayISAPI....tab%3DWatching

http://www.fostexinternational.com/d...ial-Horn.shtml

Best
JA

Hi Joe,

Yes I was monitoring those and thanks for the link.

No doubt many have gone before me but I would like to explore making some of the 290S.

I do like this set -up..something to aspire to.

http://homepages.slingshot.co.nz/~au...e%20review.pdf


Ian

Ian,

those are stunning. The horns look like originals. laminated maple. I really like
widgets resin clones though. Knowing what it would cost to make, widjets are very very good value indeed . Tad cook the maple to remove the moisture from the timber then re-machine it to remove the scorched bits. A hell of a lot of work

carved from a solid block they would dry out and split.

If money were no object I'd come and build two pairs !

Rich