"V-Trac" Midrange Horn Upgrade For Khorns

[Al Klappenberger]

Guys,

I should comment here. There is no “competition” here

between my 1 inch throat “trachorn” and Greg’s 2 inch “V-Trac”. They are both

based on Bruce Edgar’s concept. I expect their “voicing” will be very similar. The

difference between the two is that The V-Trac requires a 2 inch driver. That

will give you lower pressure in the throat for any given sound level and therefore

lower distortion. I really don’t know how much lower it will be at home stereo

listening levels. You usually see 2 inch drivers on BIG systems designed to make

a LOT of noise! You can’t just cut a 1 inch

design down to open the throat to a 2 inch design. If you do, you will find

that it won’t even be square any more but rectangular! A special rectangular to

round adaptor having a tractrix taper would have to be designed to transition to

a 2 inch driver. That would require some fancy engineering to do it correctly

and you would still wind up with a jurey-rig! It would also be very difficult

to make.

If you have my Trachorn with the stock K55 driver and want

to take the next step, I suggest that you consider replacing the K55 with a

true 1 inch throat driver, like the Altec 902 or JBL 2426 (that I am using).

Either driver will fit on the Trachorn motor-board directly without and adaptor

providing a smooth taper right down to the driver phase plug. Be careful to

pick a driver that will safely go down to 400 Hz with the network you are

using. I wouldn’t trust a 1^st order woofer / squawker crossover like

in the AA or my “Universal”. I would suggest at least one of the Klipsch AK

series networks or my AP12 or ES networks. The K55 is actually about .7 inch

diameter witch give you a “bump” right at the point where the adaptor attaches

to the motor board. If you want the absolute best and are willing to spend the

money, you want Greg’s V-Trac though. I really couldn’t say what improvement

this would give you. I’ll just have to wait until someone actually makes the

comparison. I might add that the V-Trac is a total top end, horn, frame and

grill assembly that will directly interchange with my Trachorn and grill frame.

The two, complete with drivers and all, could be swapped in or out in just a

few minutes for a very nice comparison!

BTW: Comments made by me earlier about using my Universal network

with the BMS driver were about the coaxial version of the driver Greg is using.

There should not be any problem using it with a separate tweeter.

Al K.

[Crossman]

Sorry guys, but I'm confused again - too many replys to sort through with little coherence for my small brain. I would eventually like to buy into this but I really don't want to buy parts that don't work or having the hassle of sending parts back for replacement, or sending emails and making phone calls for tech support. I just want to buy it, install it, and hopefully enjoy it.

So........lets clear the fog - exactly which components does this V-Trac system require for optimal performance?

BMS 4592ND or BMS 4592ND MID?

Al Ks Universal network or some other?

I think we've safely established it needs separate tweeters, preferably Beyma CP25

[Deang]

It's confusing because of model number BMS attached to the neodymium version of the 4591. The 4592ND is a coax -- scratch that model from the list. The two BMS drivers for Greg's horn are the 4591 and the 4592ND-Mid. The 4591 has a ferrite magnet, the 4592ND-Mid is the same driver except with a neodymium magnet.

Because of their phenolic diaphragms (go down to 300Hz), and very similar overall response as the dual phase plug K-55 -- these drivers can be used with the ALK (Universal Type A) without any problems.

The Community M-200 can also be used, but not with the Beyma and ALK networks. The M-200 goes low enough, but not high enough. The Eminence APT-200 could be substituted for the Beyma -- and the 4500Hz version of the ALK could be used (yes, there is one).

Klipsch type crossovers could be used, but not without some modification to account for the different attenuation level of the BMS compared to the K-55 (not difficult).

All other current production 2" drivers use either Ti, Al, or Be -- and will not safely go down low enough for the Klipschorn using low order filters.

[Guest " "]

May not be current production, but they show up on ebay quite frequently.....both have phenolic diaphragms

Selenium D305 (400hz - 9000hz) and Selenium D405 (300hz - 7000hz)

[Crossman]

Klipsch type crossovers could be used, but not without some modification to account for the different attenuation level of the BMS compared to the K-55 (not difficult).

What modification would be necessary? I asked Bob Crites about this, but he didn't give an answer. He was waiting to evaluate Greg's horns.

[greg928gts]

Sorry guys, but I'm confused again - too many replys to sort through with little coherence for my small brain. I would eventually like to buy into this but I really don't want to buy parts that don't work or having the hassle of sending parts back for replacement, or sending emails and making phone calls for tech support. I just want to buy it, install it, and hopefully enjoy it.

So........lets clear the fog - exactly which components does this V-Trac system require for optimal performance?

BMS 4592ND or BMS 4592ND MID?

Al Ks Universal network or some other?

I think we've safely established it needs separate tweeters, preferably Beyma CP25

This is really not that confusing. It is being made more confusing than necessary by everyone posting here with their comments.

The answers to your questions are in the V-Trac webpages. That is the definitive source for this information.

www.dcchomes.com/Vtrac.html

All you have to do is read those pages carefully and you'll know exactly what you'll need, and you'll know what to expect.

If by chance there happens to be something on those webpages that is not clear to you, the thing to do is ask the one person who knows more about the V-Trac horn upgrade than anyone else. ME! That is the best way to get answers to your questions, instead of asking people here on on an open forum who did not design, build, or have even heard the V-Trac with all the other upgrades in a pair of Khorns.

I'm very responsive to emails.

Greg

[greg928gts]

To answer any questions about a lower priced version of these upgrades.

The V-Trac was designed specifically to work with the very best upgrades available for the Khorn. I've said it before, and I'll say it again. The V-Trac is the last upgrade I would do. If you want to save money, just listen to stock Khorns. When you have a little extra to spend, go for a crossover upgrade, or maybe the woofers.

But if you want to get large format horn/driver performance, you're going to have to save up some dough. I don't know of any cheap way out. Even with all the "free" labor I put into my own system, I still had to put out a lot of money to get my speakers to where they are now.

Still, when you figure the performance level, the cost is a bargain. Even a fully clothed version of one of my Khorn restorations with all the upgrades will run less than new Khorns. Give me a choice between the Khorns sitting in my living room right now and a pair of 60th anniversary Khorns, which do you think I would take?

Greg

[Al Klappenberger]

Guys,

I just realized another “gotcha” involved here.

Every Klipsch network for the Khorn from the AK-3 on back

REQUIRES that the squawker driver have a natural rolloff at roughly 6000 Hz.

None of these networks do anything to stop output from the squawker driver

above 6000 Hz. If the 2 inch driver you choose doesn’t go up to 6000 Hz you

will have a “hole” before the tweeter cuts in at 6000 Hz. If the driver happens to go higher, you will

have an overlap and comb effects over that area. You will need to modify the network squawker /

tweeter crossover section to cross lower. A lot of mods have been discussed on

how to do that. Bob Crites offers a 1^st order version. As Dean

mentioned, my Universal network also can be modified for a 4500 Hz crossover.

Greg is about to build one of these for his own use. Maybe he can be persuaded

to describe it once it’s done. I have never built one of these 4500 Hz versions

myself.

The bottom line is that none of the Klipsch networks are

really right for a different driver than the K55, no matter what horn is used.

All this is also true for my 1 inch throat Trachorn. The JBL and Altec drivers

I mentioned earlier also demand different squawker to tweeter crossovers. Both

the JBL 2426 and the Altec 902 go way above 6000 Hz.

Al K.

[Coytee]

Hi Al...

Nice to see ya visiting! (I know you lurk from time to time)

[Y]

[Deang]

This is really not that confusing. It is being made more confusing than necessary by everyone posting here with their comments.

Going to your page doesn't clear up the confusion on the drivers because you refer to it as the "4592ND midrange only". When I read that, I was confused because I knew the 4592ND was a coaxial. I didn't even know a midrange only version existed until Gaspr posted the link to it. The way to avoid confusion is to call it what BMS calls it -- 4592ND-MID. You also don't mention the ferrite magnet version (4591), which is kind of odd. At any rate, if someone orders a 4592ND, they're going to get a coaxial. Someone asked about a less expensive option, so I suggested the Community M-200 and Eminence APT-200 -- which would cost about half as much as the BMS/Beyma option (and still sound damn good). You shouldn't be so quick to close the door on other options -- I thought you wanted to sell horns? Now, I didn't deserve to be smacked down like that, I was only trying help, and everything I said was accurate. Good grief, I've been suggesting the 4591 for almost two years, and Dennis has been suggesting the M-200 since before I was born!

You really can't start a thread like this on an open forum and then not expect people to make comments or suggestions, especially in a section called 'Updates and Modifications' and inhabited by DIY types. If you don't want comments, then ask Amy to close the thread.

Hi Al,

I've attached the plot of the BMS 4591, which is the ferrite magnet version of the 4592ND-MID. As you can see, it starts to roll off pretty fast at 6kHz. BMS shows 118dB on their horn. The K-55/K-400 is 107dB -- so 11dB difference. I suspect sensitivity might be a little less on a non-CD horn like the V-trac. Point being, any of the old stock Klipsch networks would work with tap and cap change in the short term. It would allow this upgrade to be done in steps, which is a lot less strain on the checking acccount.

http://bmspro.com/fileadmin/bms-data/curves_compression/ferrite/bms_4591_curves.jpg

[jwc]

Yes Al....nice to see you posting.

Speakerfritz may have mentioned this but i beleive the Selenium 405? can go down to 400Hz. It used to have a phenolic diaghragm but now Ti.....not sure if the phenolic diaghragms are still available.

Also the JBL2482. Massive driver with phenolics. You can ususally get a good pair from....

http://www.jamminjersey.com/speakers.php?prod=jblcomp

They may get weak before 5800Hz though...may need to XO lower......not sure.

jc

[Al Klappenberger]

Dean,

Looking at the curves a bit says that driver should do fairly well with the Klipsch crossovers. There will be some overlap above 6000 as I think it goes a little higher that the K55V and a bit higher yet than the K55M. It should do ok until the next upgrade step, a new crossover. Adjusting the levels by moving the transform taps has been coverd to death all over this forum. It shouldn't be hard to do. I suppose the best way to simplify all this is to stronly suggest that only that driver be used. The object in offering the V-Trach horn is no compromise performace, so why cut corners on the driver with some "unknown".

GO FOR IT!

Al K.

EDIT:

The curves I speak of are those posted by Dean above. Find the driver model numbers on the curves. I do not want to add to the confusion by typing the wrong number. My dislexia often causes me to do that.

All the Klipsch networks that use the "Elliptic" tweeter filter (AK-2, AK-3) use the same exact filter. Computer analyis shows that it cuts off neatly at 6000 Hz. This should work quite well with the driver mentioned above.

EDIT2:

I looked at the tweeter filter on the AA network. It has a crapy passband response and cuts off too low. I suggest changing the input 2 uF cap (The one connected between the .245 mHy inductor and 13 Uf cap) down to 1.0 or 1.3 uF. This moves the cutoff up to 6000 Hz and also smooths out the passband. This would be an improvement for the AA in virtually all speakers.

[Deang]

Greg, I just read your post again and think maybe I over-reacted. I guess I'm getting a little sensitive in my old age. I also suffer from Depression, which sometimes makes me more Hyde than Jekyll!

[greg928gts]

Dean, my comment about people making comments wasn't directed solely at you. Although, I was confused by what a Community 200 is, which is exactly my point, that people make comments here without giving out all the information, which is what causes confusion. I don't think you meant to cause confusion when you mentioned the Community 200 without saying what it was, it's just the way it happens sometimes.

But hey, it is an open forum, so if everyone wants to banter stuff about here and there willy nilly without really being clear about everything and cause confusion, then go for it. There's been a lot of that so far, so why stop now.

The driver was sold to me, listed on the invoice as a BMS 4592ND Midrange Only, so that's how I referred to it until just recently when I saw the other designation BMS 4592ND-MID. On the back of the driver is says BMS 4592 Middle - No ND, no MID, no Midrange Only. So obviously BMS has got some issues with model numbers. But for crying out loud, isn't it pretty obvious that it's a midrange version of the BMS 4592 regardless of how you say it? And if it's confusing, let's see, why don't I go on an open forum and tell everyone that it's confusing instead of emailing the person who is selling the product. I don't know, you all do what you want, what do I care really.

I didn't mention the 4591 because at the time I did the webpage, I hadn't tested the 4591. Besides, I could make a case for not recommending any particular driver, just the parameters that are necessary for the driver to work with the horn. I thought I covered that by saying that it must be a 2" driver with the capability of being crossed over at 400Hz and also be able to extend to 6Khz. Then I make my recommendation about which driver I would use. When I read the webpages it seems pretty clear to me, but I'm open to making clarifications if needed.

I don't have the tolerance for people wanting to find cheap ways out of things. I know maybe I should, but I don't. What happens is, someone buys the V-Trac, then buys cheaper drivers and hopefully makes the correct mods to their crossovers, and then they aren't happy with the sound. Next thing you know, they're coming onto this open forum and telling everyone how their experience with the V-Trac horn didn't work out so well, and I end up having to defend it. I'd rather make the recommendation to do it right the first time, and anything less is at your own risk. We're talking about a luxury item here. This isn't a roof over one's head, it's a fricken speaker. If you can't afford it, buy something a little less expensive and be happy with it. Cripes.

Greg

[greg928gts]

Dean,

Looking at the curves a bit says that driver should do fairly well with the Klipsch crossovers.

Al K.

Here, I'll pick on Al just a bit.

"that driver" ? Which driver are you talking about? See the confusion? This what I was referring to, and it is why if people have questions about this V-Trac package, they ought to just contact me. BTW, a lot of people have, and I'm very responsive to them.

The object in offering the V-Trach horn is no compromise performace, so why cut corners on the driver with some "unknown".

Thank you! Exactly! Either this luxury item fits into your budget or it doesn't. If you want to cheap out, go build your own horn. Cripes.

Greg

[Guest " "]

Greg

One issue is that you put this in upgrades and modifications in stead of the garage sale section.....folks tend to not clutter item for sale posts that are in the garage sale section with comments....also...keep in mind that when you started this initiative it was an openly discussed item there was a lot of info exchanges and questions by you which were answered by folks on the forum...sorry to say this but your actions imply that now you are a horn expert and don't need anymore input.

[capo72]

Thank you! Exactly! Either this luxury item fits into your budget or it doesn't. If you want to cheap out, go build your own horn. Cripes.

Greg

Hey, I resemble that remark!

I admire the work you have put into this Greg. I hope you can sell a few.

Jeremy

[greg928gts]

sorry to say this but your actions imply that now you are a horn expert and don't need anymore input.

That's stretching it a bit.

Whatever.

Greg

[Guinness]

Beautiful horn Greg!

I've been using the BMS 4591 driver for a few years. I let it roll of naturally on the top end and cross the tweeter at 7000 Hz with a second order Butterworth filter. I have not measured it but, it sounds very good there. I tried 6500 and 7500 before settling on 7000.

The response curve for the BMS 4592-MID looks nearly identical to the 4591.

[gaspr]

I've been using the BMS 4591 driver for a few years. I let it roll of naturally on the top end and cross the tweeter at 7000 Hz with a second order Butterworth filter. I have not measured it but, it sounds very good there. I tried 6500 and 7500 before settling on 7000.

The response curve for the BMS 4592-MID looks nearly identical to the 4591.

Can I ask what horn you are using??