2-way crossovers

[4313B]

*****

Oh, I see where that came from...

It's never actually done, but you may enjoy it all the while....

No, I would imagine most people have an endgame in mind.

[Zilch]

"Open-ended" is apt.

There IS no product, all ongoing upgrade....

[4313B]

"Open-ended" is apt.

There IS no product, all ongoing upgrade....

You're so silly. It's quite tiresome.

[Ian Mackenzie]

Tireless is perhaps more apt.

Jorg,

How are you going?

I looked at your start post and my first clue was what is the native response of the BMS driver on the Altect 511 and the 2235 on the baffle you propose to use?

As pointed out by Dave measuring and working all this out is a bit of an issue unless you have a significant resources at your disposal.

I did a quick yahoo search of the 4550 driver and interestingly found this link to some data and Bill Martinelli's wood horn page

http://www.woodhorn.com/BMS/bms_4550.htm

http://www.woodhorn.com/diy.htm

May I (respectfully) suggest you attempt to use this as a powerful resource for the development of your project. You may also find that using one of Bill's horns will assist in realising the full potential of your compression driver.

http://www.woodhorn.com/completespeakers.htm

[4313B]

Tireless is perhaps more apt.

No, not in this particular instance. "Tiresome" is the description I most often hear, usually preceded by "real". I suppose it's too bad really, well, at least given the venue. We've had this discussion with respect to various other much larger forums and there's just not a whole lot to be done about it.

Anyway, whatever.

[Zilch]

Here's BMS 4550 on 511 (also 811) horns:

http://audioheritage.org/vbulletin/s...290#post159290

Here's Earl's explanation of those curves:

http://audioheritage.org/vbulletin/s...367#post159367

Here's the impedance curves:

http://audioheritage.org/vbulletin/s...554#post164554

Here's the compensation filter w/846B XO, including voltage drive:

http://audioheritage.org/vbulletin/s...687#post163687

Here's the sim of the 16-Ohm version:

http://audioheritage.org/vbulletin/s...709#post164709

And here's the filter as-built:

http://audioheritage.org/vbulletin/s...77&#post165377

Scroll up to #745 for the parts list.

Frankly, I don't understand why I deserve a rash of shit for this.

Whatever.... :dont-know

[Ian Mackenzie]

So the journey is the reward?

Would the combination of L200 LF filter ( if I go 2235 ) with the N800-8k HF filter and your compensation be a good start point for this project?

If I found I needed to cross the HF lower I would have to modify the notch filter to extend the attenuation down?

I would keep the zobels as they are?

What would you recommend as a starting place for hardware and software test equipment for this DIY journey?

I have a 200w Sumo and a 50w Musical Fidelity. Might it make more sense to spend the test equipment money on a bi-amp setup? This bi-amp would be flexible enough to accomodate other two way's I might try to mess up down the road? Rod Elliott's article sure makes that seem attractive.

Jorg

Jorg,

The later might work our best with your potential future plans

Marchland have some reasonable active crossovers. You can arrange custom crossover points with some of their models.

On software there are some RTA software packages on the internet that you can down load and try out like SmartLive. Go buy an Behringer ECM8000 mic and and a small phantom powed mic preamp and you can do some basic measurements via the soundcard in your PC.

If you want to play around with passives there is a firm that sells an experimenters adjustable passive crossver boards..they were at the CES. You can find their advert in AudioExpress magazine. Sorry I don't remember the name.

The intent of my earlier post was that you either have plenty of time to learn, fiddle and hopefully get it right or rely of someone else's hard work and use a pre designed system that already sings.

In that respct Bill's work is very impressive....as can be seen from his web pages. They would appear to have good WAF which is always an issue with diy horn based systems..trust me!

On your earlier comments about time alignment the issue is more about getting an even on and off axis vertical polar response in the crossover region.

The 511 horn has far more resonant and response lobing issues that would benefit considering alternative horn types and large format drivers over any attempt at time alignment.

Again look at Bill's designs, he appears to use BMS drivers so it may pay to email Bill for some feedback on your particular BMS driver.

Ian

[Zilch]

He has the 511 horns, Ian, and wants to work with them.

Advice noted, but too late. I'm now the proud owner of some 511b horns.

Then I am decided.

511b, BMS 4550, 2235, N801-8a

I'm saying, "Fire 'em UP!"

He'll soon know if those are issues for his system....

Here's the precedent thread in which the basic design was developed:

http://audioheritage.org/vbulletin/s...ad.php?t=16946

[4313B]

Frankly, I don't understand why I deserve a rash of shit for this.... :dont-know

Yes, we know that. It's basically a perception problem that we've discussed to death over the last three years.

I've decided to delete the other three paragraphs I took the time to type in this post because I realized that they would take an additional three paragraphs to explain further and I just don't have that kind of time right now.

[Zilch]

Well, PM them to me, then.

[Couldn't hurt.... ]

[Ian Mackenzie]

Ah we where posting at the same time.

Zilch, with all your posting can you honestly say you auditioned the 511 and the 2235H woofer?

The 511 was primarily designed for use in particular Altec systems.

On ME150H this a similar exercise with support from Earl

http://www.audioheritage.org/vbullet...ad.php?t=10873
http://audioheritage.csdco.com/vbull...ead.php?t=6006

And a response curve of the ME150H which was used in particular JBL systems as we know.
http://www.behringer-electric.de/ls/RareInfosME150H.htm



From Jorg's posts it would appear he wants perfection and he will need to undertake a reaonable amount of time, expense and effort to approach that goal.

No doubt some would say buy a DEQX to make it go.

I am only suggesting a wider perspective on reality before he embarks on his journey.

As you know the 2344 horn was created for a reason.

Yes I saw that link just now. Why was this thread not link in the first instance??

It would appear everything that has been discussed here and already been looked at over there.

Its a mess.

[boputnam]

Try listening to some finished product sometime...

I concur with that. Live with it, and really understand it's performance. Subtle "adjustments" can reap remarkable changes in performance - good, or bad...

No doubt some would say buy a DEQX to make it go.

Agreed. And that there poses a question: Does one accept an imperfect design because one can EQ the "hell" out of it to make it perform satisfactorily? Sure, the DEQX technology can achieve remarkable end-results, but it does so dealing with symptoms of problems...

:dont-know

[Zilch]

Zilch, with all your posting can you honestly say you auditioned the 511 and the 2235H woofer?

Nope, LE14H-3 mostly, over the course of several months. I'll set up to do that (511 & 2235H) here, now that you mention it, tho.

It'll be couple of weeks listening to it for me to give that system a fair audition. I doubt I'll have much to add in the meantime.

Why was this thread not link[ed] in the first instance??

Don't look at ME, Ian.

It's certainly not MY style....

[boputnam]

Sure, the DEQX technology can achieve remarkable end-results, but it does so dealing with symptoms of problems...

:dont-know

Quoting myself...

Those of you interested in perspectives on DEQX, can read/participate in an intense discussion on Gunness Focussing on ProSoundWeb, where the DEQX is, at the least, anecdotally addressed. The discussion there, is very interesting and IMO universally relevant for us all.

Real time convolution of and impulse with the signal is merely the means of output. Systems like the DEQX I would call brute force convolution. Stick a mic up in a room, take an impulse, assume that everything about it is LTI and spatially invariant, invert it, and then convolve with your signal.

All you have achieved then is cleaning up the signal at one point in time and space. Move the microphone a few inches, or increase the level of the system outside of its nicely linear range, and this correction no longer applies.

Dave (Gunness) has systematically disassembled the beast, looking at behavior in the phase plug, horn, woofer modal behavior, etc. He has figured out what is spatially dependent, and what is not, what is LTI, and what is not.

Thus you end up with a product that may not correct "everything" ala DEQX, but is has fixed the problems that show up as LTI and spatially uniform, including several pesky energy storage issues in cones, horn flares, and phase plugs. ... Dave Gunness is due a lot of credit here for his analysis techniques.

Phill Graham
Doctoral Candidate
Georgia Tech

Grist for the mill...

[Ian Mackenzie]

Agreed. And that there poses a question: Does one accept an imperfect design because one can EQ the "hell" out of it to make it perform satisfactorily? Sure, the DEQX technology can achieve remarkable end-results, but it does so dealing with symptoms of problems...

:dont-know

Exactly my friend.

Nope, LE14H-3 mostly, over the course of several months. I'll set up to do that here, now that you mention it, tho.

It'll be couple of weeks listening to it for me to give that system a fair audition. I doubt I'll have much to add in the meantime.

Okay, I look forward to reading your impressions at some point

Perhaps you can see now why I might have been seen on the face of it to be overtly "anal" in another thread where seemingly a beginner leaps for what he thinks is the easy way out or ultimate route to cleansing a dated but mature design with digital technology.

The passer by then reads this some time later ...and well you know the rest.

Ian

Sorry but I do confess to being something of a disciplinarian with this sort of thing!