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Ken Pachkowsky
08-25-2003, 08:54 PM
Hi all, been away for a while. I have a question for you guru's out there.

If space and a good budget up to 10 grand where available, what hybrid 43XX series would you create. For example: 4355 using dual 2245H's or the standard 2235H's.

I very seriously want a description of your ultimate dream system including the component list and type/model of active/passive crossovers including crossover points.

Any and all opinions would be very much appreciated.

Ken

Alex Lancaster
08-25-2003, 09:30 PM
Hi:

I am no guru, but check my thread "BIG monitors" on general.

As far as xovers, JBL 532/3 or 5234 around 200-250Hz.

3107 with bypass caps from 200-250Hz up.

I promised to post pics but have not been able yet.

Alex.

Ian Mackenzie
08-26-2003, 03:14 AM
Ken,

I can't imaging a better no holds barred monitor than your present system in the right environment.

The only contendors would be from the same stable.

However, that said I've read of a system in European studio using a 30 inch fostex woofer sub, dual 2226 mid bass, a single 4 x 2118s, an inverted 2440 with exposed 4 inch titanium dome (no horn), and fostex super horn, the crossover was a secret custom job and power by 4000 watts a side.

More recently, the newer JBL SR L32 has found favour with the Bag End sub.

regards

Ian

Alex Lancaster
08-27-2003, 01:24 PM
Hi:

I have nos 3107's (4350), how would You bias them?, I planned to use the bypass caps as described elsewhere.

Thanks: Alex

Mr. Widget
08-27-2003, 01:28 PM
Originally posted by Giskard
I'd consider allowing the 2202H's to roll off naturally and then add in the dual 2235H's on the bottom as required with a variable active low pass filter.

I have tried both setups with the 250-290Hz crossover on mine. I still haven't finished with my tweaks, but so far I haven't come to a definitive conclusion regarding the crossover between the dual 2235s and the 2202. I definitely prefer the more open sound of not listening to the midrange on up through the active crossover, but when pushed to high SPLs I feel the 2202 may be adding grunge since it is trying to reproduce 20Hz. I have a new active crossover that is very open sounding. I have been enjoying it immensely on another system and will try it on the 4355s soon.

Mr. Widget
08-27-2003, 03:29 PM
"No, the 2202H isn't trying to reproduce 20 Hz.:) "

I know that, I am prone to slight exaggeration at times.:)

I can't push these monsters for more than a few minutes as I give out, but I want to be able too!:D

Widget

speakerdave
08-27-2003, 05:29 PM
A couple of questions about this:

If the response is rolled off by constriction and there is also a filter, do the rates compound?

A driver rolled off by constriction is still getting its share of power the amp is putting out at those frequencies below the rolloff hinge. Will the voice coil actually heat up more because the energy cannot be dissipated by conversion to mechanical energy? In other words, does the driver have to be able to take the punishment?

This is important to me because I am considering using a pair of Stephens 80FR as bass-mids.

Thanks,

David

Tom Loizeaux
08-27-2003, 06:00 PM
I was standing in a recording studio today as they were removing a pair of big Urei monitors. I don't know the model number, but they were the ones with the 15" co-ax and an additional 15. The co-ax had the Urei blue straight-sidded horn and and one of the woofers looked like a Gauss or EV because of the cast finned magnet cover. These were in LARGE cabinets and had a sophisticated Urei crossovers. The engineer said he prefered these to the big Genelec monitors hanging next to them! I'm sure these Urei's sound great. I also agree that Ken's Westlakes will sound wonderful as well.

As I've said before, my fantasy would be to build a tower version of the JBL 4350 (4355) using the current "best available drivers" to complete the system. Getting the cabinets to stand about 5' tall would help with the sound stage. I would definately bi-amp these at 250 Hz and would use the 3107 crossovers after tweaking them to modern specs. I think the dual 2235Hs in a large cabinet would cover the low end as well as any other drivers and the 2" compression drivers would be hard to beat too.
Then, of course, I'd have to buy a pair of outstanding stereo amps (Mark Levinson?) to get the most out of these.
Does it get any better then that? I don't think so.

Tom

Robh3606
08-27-2003, 06:25 PM
Yeah I am partial to my Urei clone. If I ever get my hands on another pair of 801C drivers I would be tempted to try a matching LRC 811C front end for my HT. There is something about them that is hard to describe. Voices/instruments are just so natural sounding through them. Don't know if its the point source or just a good pairing between the E-145 2425 and horn or both.

I think I would like to try large format compression drivers, a system like the 4355 sounds like a real killer. Must be lots of fun to kick back in front of a pair of those and just let your favorite kick a** tracks rip:D

Heaven on earth;)

Rob:)

Ian Mackenzie
08-27-2003, 09:29 PM
Widget,

Hi there,

If you are after perfection, a minimalist passive high pass filter between the preamp outptut and the mid/high amp using a nice film/foil capacitor/resister may do the trick.

The slope would be only 6 db per octave as opposed to 12 as recommended by JBL but it would certainly reduce any intermodulation and be as transparent as a filter can be.

I recall JBL adopted a similar scheme for the high pass output of the BX 63 sub crossover (ie no chips in the signal path)

Ian

Mr. Widget
08-27-2003, 10:16 PM
I have thought about doing a passive high level filter, however I don't have any formulae for calculating values that would provide different turn over frequencies for the different input impedances of my various components etc. To be fair I haven't even done a simple google search for info. I do think that a properly designed first or second order passive high level network with premium components is probably the ideal minimalist set up. If I ever get finished with this project I may try it out.

Ian Mackenzie
08-27-2003, 11:41 PM
Oh I understand,

I think I am also in the same boat.

regards

Ian:smthsail:

Mr. Widget
08-28-2003, 12:01 AM
I just did a quickie google search and came up with this. It looks like a good starting point.

http://www.t-linespeakers.org/tech/filters/passiveHLxo.html

Tom Loizeaux
08-28-2003, 04:08 AM
The Parts Express catalogue has this table in it. It shows caps and coils required for 1st, 2nd & 3rd order networks for use in 4, 8 and 16 ohm systems. Once you see the chart you'll see that you can expand it, if necessary, to cove a larger range.

Tom

Mr. Widget
08-28-2003, 10:13 AM
Originally posted by Tom Loizeaux
The Parts Express catalogue has this table in it. It shows caps and coils required for 1st, 2nd & 3rd order networks for use in 4, 8 and 16 ohm systems. Once you see the chart you'll see that you can expand it, if necessary, to cove a larger range.

Tom

Hi Tom,

I didn't take a look at the Parts Express site, but you mention coils and speaker impedances, so I assume the table they are showing is for the standard Butterworth filters for passive crossovers used after the amps.

The filters Ian and I were discussing are used between preamp and power amp. They are a very simple and audibly superior way to create a bi-amped system, but are not as convenient to use as a variable frequency active crossover and they do have insertion loss.

Widget

Ken Pachkowsky
08-28-2003, 12:12 PM
The quest for nirvana can be never ending!

I think it was Mike whom I quote "You will have to upgrade your amps to get the most out of those Westlakes". Boy, was he right!

My Haflers are just not up to the task.

I am in the market for new amps.

I was thinking "due to the limited cable lengths at only 6 feet" of purchasing a pair of the Adcom 7805's and leaving one channel open. This would be one amp per side, mounted under the stands solving the short cable problem. These are rated 300 watts per channel at 8 ohm load. I only wish these supported strapping individual channels so I could double up on the 2235's.

I have also thought of using Bryston's, but have done no research as of yet on there product line. I will get serious on this come the end of October.

The ideal amp would be a 4 channel or a 5 channel with strapping 2 channels as an option.

Any suggestions would be appreciated. Keep the budget around 5000.00.

Ken

Ian Mackenzie
08-28-2003, 08:15 PM
There is an image from an old Studio Journal advertisement I thought may appeal here.

Ian

Ian Mackenzie
08-28-2003, 08:27 PM
Now this is going to look real familiar to Ken.

Actually I have sent Kent & Widget an article in the journal by the designer regards these monitors. Sing out if you would like to view it (too large for the forum)

Ian

Ian Mackenzie
08-28-2003, 08:40 PM
Of course there's no show in the super monitor league with Urie right Rob.

Ian

Robh3606
08-28-2003, 09:11 PM
Wow great stuff Ian!!! Where did you find it?? I certainly would like to see it.:D

Rob:)

Ian Mackenzie
08-28-2003, 10:27 PM
Cool Rob,

I'm emailing you some hi res particles as I type, this image was from Studio Sound Decemebr 1986, my I am show my age a bit now arn't I.

Well I'm sure more than a few of us fit that era so its all the more appreciated. By the way they canned the Tannoy FSM monitor in the same issue...no more need be said.


Ohh , look whats on the inside back cover, if only .

Ian

boputnam
08-29-2003, 07:22 AM
I'm in!!


Now this is going to look real familiar to Ken. But, ain't that a 2405 in the center there? Older version Westlake, eh?

And, I may be mistaken :duck: but isn't that a rack of Crowns over there...?

So, as the joke goes, "what ya using for rears...?" :rotfl:

Ian Mackenzie
08-29-2003, 07:42 AM
Bo,

The Man with Cats eyes, correct on both counts.

On the rears perhaps 5.1 was just a twinkle in the eye then, although Pink Floyd may take the prize on that one.

I think this firm (Reflection Arts) may have been one of many Studio installer contractors of that era and this design was very much the vogue of that time.

Westlake however, appears to be a long term player and its designs have stuck, particularly in larger venues where they need to impress the client for those big bucks.

Anyone wanna take a guess on the mid cone in this monitor?

Ian:)

4313B
08-29-2003, 07:50 AM
The photo is pretty grainy but my guess would be a 2121 due to what appears to be a 4" inverted dust cap

boputnam
08-29-2003, 07:53 AM
Anyone wanna take a guess on the mid cone in this monitor? That has me stumped me too - it's a 10-in, I recon, based on comparing to the 2231's (aren't they?).

But :rotfl: if Ken Pachkowsky is looking, I think this room design will solve ALL his Westlake worries! And, boy do I wanna visit once the refurb is complete! ;)

Ian Mackenzie
08-29-2003, 08:13 AM
Yeap,

Its a JBL 2121, the blurrb in the article said it was the finest unit available for this purpose...well not much has changed in 20 years apart from model numbers.


Ian

boputnam
08-29-2003, 08:51 AM
From Ian's article he shared today - this is certain to elicit some rants!

:D

4313B
08-29-2003, 09:11 AM
"this is certain to elicit some rants"

Why? :confused:

boputnam
08-29-2003, 09:31 AM
I expected the discussion of compression driver size to get some juices flowing...

Robh3606
08-29-2003, 09:44 AM
Yeah me too! Those slow large format drivers just can't get out of there own way. Who needs a 4" edge wound coil driving a feather anyway:eek:

" The ultimate for midrange reproduction. Steep waveforms of explosive loudness are effortlessly reproduced"

Ha who wrote that crap! Poppy cock!!

Rob:)

4313B
08-29-2003, 09:56 AM
"Yeah me too! Those slow large format drivers just can't get out of there own way. Who needs a 4" edge wound coil driving a feather anyway"

The author needs to review Technical Notes Volume 1, Number 8 :)

Mr. Widget
08-29-2003, 10:17 AM
Ian was kind enough to send me the entire article. I read it with great interest. They made many interesting points, and several times said that the reason they picked this or that driver was the taste of the end user and not one of empirical superiority.

That said, in my own explorations, I must emphatically disagree with their assertion that a 1" exit compression driver is superior to a 2" exit compression driver. I would agree there are times to use a 1" driver, but over the range between 1200Hz and 10KHz in my experience with JBL, Altec, and Meyer drivers that is simply not the case. As they point out in their article the driver is only half of a two part system comprised of a flair (horn) and the driver. I would speculate they didn't try the right 2" horns.

All in all it was interesting that despite their attitude of breaking fresh ground on the development of high power studio monitors, they ended up with a system that was surprisingly similar to the JBL 4350/55 and the Westlake monitors.

Ken Pachkowsky
08-29-2003, 10:20 AM
Here we go. It's raining large Westlakes. Looks like a 2122 to me.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2553040788&category=23786

Have a good day.

Ken

4313B
08-29-2003, 01:02 PM
"If the response is rolled off by constriction and there is also a filter, do the rates compound?

Yes

"A driver rolled off by constriction is still getting its share of power the amp is putting out at those frequencies below the rolloff hinge. Will the voice coil actually heat up more because the energy cannot be dissipated by conversion to mechanical energy?"

Not if there is sufficient air movement, which there should be if you are running it on down. I've used countless 112/2108/2121/2122/2202 transducers in such a scenario and have never burned up a coil.

"If you are after perfection, a minimalist passive high pass filter between the preamp outptut and the mid/high amp using a nice film/foil capacitor/resister may do the trick."

It's been doing the trick for 20+ years now ;)

"The slope would be only 6 db per octave as opposed to 12 as recommended by JBL but it would certainly reduce any intermodulation and be as transparent as a filter can be."

The larger JBL cone transducers are up to the task of handling 6dB/octave filters. The 6dB/octave filter maximizes transient response. It's a Bessel by nature.

"I recall JBL adopted a similar scheme for the high pass output of the BX 63 sub crossover (ie no chips in the signal path)"

True, a bit limited but it could have been worse :) Good enough for mass market consumer stuff.

"I have thought about doing a passive high level filter, however I don't have any formulae for calculating values that would provide different turn over frequencies for the different input impedances of my various components etc."

Well I shouldn't have brought the subject up yet again I suppose.

"I just did a quickie google search and came up with this. It looks like a good starting point."

Cool! :)

Anyway, sorry for opening this can of worms again. I've never had any trouble with any of it but I guess it is possible for some people to start blowing shit up if they aren't careful.

4313B
08-29-2003, 03:21 PM
"I have nos 3107's (4350), how would You bias them?, I planned to use the bypass caps as described elsewhere."

Hi Alex,

Here is a repost since there seemed to be a problem with the original. I went ahead and redrew it to fit the 800 width limit.

Robh3606
08-29-2003, 03:34 PM
Hello Giskard

Very nice!! So the 2440 just rolls off. Lot's of caps in that one!!

"The author needs to review Technical Notes Volume 1, Number 8"

Where do you find them if they are not in the regular Tech Lib??

Hello Mr Widget

I have never had the pleasure of having large format drivers in my home but I had the oportunity to hear some at the MAF. I spent a good amount of my time in Dr. Edgars room listening to the Titans. They were really nice and the midrange was great!! Fast and dynamic, clear as a bell. Just as effortless as it gets.



Rob:)

4313B
08-29-2003, 04:02 PM
"Lot's of caps in that one!!"

Yes and they are big too. Just one poly/foil will run $40 to $50 if a person goes that route :(

"Where do you find them if they are not in the regular Tech Lib??"

Yeah, I noticed many of the Tech Notes are missing. I sent an email asking them to put them up on the site. I'm hoping because they are Pro :) and not Home :rolleyes: they will come through :D

Alex Lancaster
08-29-2003, 04:13 PM
Giskard:

WooWW, let's do it again!

So from the + of the battery, to all the points marked +9V?

Could You use a regulated 9VDC power supply?, I have a bunch of electrolytics for it.

Where can I find the original 3107 schematic?

Thanks Loads.

Alex.

4313B
08-29-2003, 04:24 PM
Yes

http://www.jblproservice.com/navigation/Network%20Schematics.html

Alex Lancaster
08-29-2003, 05:05 PM
Got it! Thanks again!

Alex.

Ian Mackenzie
08-29-2003, 07:18 PM
Love that schematic and Widgets review of the article.

Having got some ZZ's I actually had a good look through the whole magazine this morning and it would appear they wrote the whole issue (Dec 1986) around monitors and theres a heap of adverts and press releases in it.

I also see there is opposition to the Reflection Arts approach by Quested and another outfit from Europe. These guys seem to be pushing cones and domes, most likely Dyaudio or the ATC super dome.

Given this was a U.K Journal perhaps JBL and others like Westlake, Reflection Arts etc were trying to break into the UK market with an alternative offering to the Tannoys, Genelec and BW 802's.

Has anyone had any experience with these and which is best for the ultimate Large Format Monitor??

Ian

Ian Mackenzie
08-29-2003, 07:22 PM
Now here's and interesting beast, that looks a lot like a JBL 2123 10 inch mid and a dynaudio D 52 and D 28 in there.

How dare they mix a JBL thoroughbred from the US of A with those poached eggs from Denmark! I mean hello?

Ian:o

Tom Loizeaux
08-30-2003, 06:36 AM
Mr. Widget,
You're right that the Parts Express tables are for "speaker builders" and are for assembling passive networks.
I agree that active filters are the way to go, but most bi-amp systems also use passive crossovers or filters somewhere in their high frequency set up.

Tom

Ian Mackenzie
08-30-2003, 07:02 PM
I thought this link was interesting enough to post here for would be doers of the Ultimate Large Format Monitor.

Although again somewhat of an empirical account of whats good, bad and why, Nelson Pass and may shed some light on just why older style large format speakers sounded so great.

http://www.passlabs.com/prodlit/rushmore.htm

Part of his design quest was to research the virtues of old and rather large boxes and apply of best of the past with current state of art electronics to create a fully active system.

Here is a snippet of a PR document (by Nelson Pass) who recently turned speaker builder.

Ian

4313B
09-01-2003, 05:40 PM
Originally posted by Robh3606
Where do you find them if they are not in the regular Tech Lib??

Rob:)

Here it is Rob. :)

Technical Notes Volume 1, Number 8, Page 1

4313B
09-01-2003, 05:41 PM
Technical Notes Volume 1, Number 8, Page 2

4313B
09-01-2003, 05:42 PM
Technical Notes Volume 1, Number 8, Page 3

4313B
09-01-2003, 05:42 PM
Technical Notes Volume 1, Number 8, Page 4

4313B
09-01-2003, 05:43 PM
Technical Notes Volume 1, Number 8, Page 5

Robh3606
09-02-2003, 06:49 PM
Thanks!!! That was a nice surprise.

Rob:D

4313B
09-02-2003, 09:41 PM
You're welcome! :)

4313B
09-30-2003, 06:15 PM
Technical Notes Volume 1, Number 8, Page 6

gene6
03-09-2005, 04:55 PM
my name is gene,I have a problem with my cabinets.I am using jbl 2245h/2202h for mid bass, 2344 with 2425h/ and 2404h. the cabinet is 54 inch height ,29 wide and 19 deep. my ports are 4 inch dia, and 5 and 6/8 lenth.were is the bass. sorry the wood is birch and3/4 inch thick any Ideas may the port. thanks .geneminniefield6@msn.com

Robh3606
03-09-2005, 05:15 PM
Hello Gene

Well it would help if we knew the box volume. Are those dimensions inside??
How much used for the subenclosure on the lower midrange driver 2202?? With 2245's you should be fine but they need some breathing room around 9 cubic Ft in the 4345 monitor as an example. Those rough out to 17 cubic ft. so you have the room. Looks to me you need at least 2 4" ports are those singles???

I am using WinIsd

http://www.linearteam.dk/default.aspx?pageid=winisd

Free download already has the 2245 loaded

Rob:)

gene6
03-10-2005, 06:47 PM
hello rob. out side dimension 54 height/29 wide/19 deep.subchamber for the 2202 is 14inch hight and 14 wide and6 inch deep.I have too ports per cabinets .4 inch diam/6.5/8 in lenth. I took after the design on gould sound model 14.I have no pictures yet, but when i do i will send you some. if you want you can go to goldsound.com and check out kit 14 thanks gene.:barf:

4313B
03-10-2005, 07:13 PM
www.GoldSound.net (http://www.GoldSound.net)