LSR32 Preliminary Report

[Tom Loizeaux]

I am curious to hear how the LSR32s stack up against some other well known JBL studio monitors. I do think the LSR sub should be used with these as that was the intention of the design.
I heard some time ago that, though JBL talked about how hi-tech these were, others said they just didn't sound hat good.
I am curious to hear some informed opinions.

Tom

[speakerdave]

Ron K:

Thanks for the data on your project. That's a very handsome bit of craft you've completed there, and, again, it's such a good idea.

I hope JBl/Harman has got this tuned in. Not everyone is going to want to match a pair of LSR12p subwoofers ($1000 ea) with the LSR 32s. That comes to four grand for the whole set, and, well, you can get a pair of Jubals with original boxes for that and enough left over for milk for your cat. People may like these speakers, yet they're still going to want more bass.

JBL could make a serious re-entry into the hobby speaker-building market with a kit of drivers and crossovers and a choice of woofers, the 2235, 1400nd, 1500AL--whatever--with a filter engineered for each and cabinet plans.

There is kit-building and speaker building going on in this price range.

Well, anyway--I think it's a good idea.

That midrange and tweeter--with their crossover--are a dynamite combination. I'd just like to see people be able to have access to it without stepping into a lot of unnecessary difficulty and expense matching it with good bass. The LSR series are near and mid-field monitors. The technology should be adapted to in-home use and made available to the DIYers in pre-engineered packages.

My two cents.

David

[Alex Lancaster]

I can imagine JBL not wanting to get into the DIY kit market, because of the support problems it would generate; For $1000, You can get -new- S312's and a S120P sub, and just hook it up.

What do You guys think?

Alex.

[speakerdave]

Originally posted by Alex Lancaster
I can imagine JBL not wanting to get into the DIY kit market, because of the support problems it would generate. . . .

Yeah, I suppose they got out of it for a reason, but I always kind of assumed that by the end of the seventies that kind of activity had died way down because the people who got into it in the '50s and '60s had done it and the people who were fooling around with speakers in the '70s were, like I was, buying the big old stuff at garage sales and flea markets, or they were doing things like stacking Advents and so on. I've heard it said that it was actually JBL who helped relaunch speaker making with their articles in Audio Magazine on how to make the big 2235- and 2245-based subwoofers.

Originally posted by Alex Lancaster

. . . . For $1000, You can get -new- S312's and a S120P sub, and just hook it up.

I'm not familiar with these speakers, but I'm guessing that at that price they are not quite the equivalent of the LSRs. If they were everybody would be buying them.

I think a lot of people are like me in that I am not trying to cheap into the cheap sounds--I'm trying to cheap into the good sounds. And because I'm a workin' guy I think if I've got a table saw and a bottle of glue I can follow a drawing for a box. The stumbler is the crossover.

I just look at that fabulous set of speakers Ron has made there and realize that a lot of people could try it and not come out with as good a result because they do not have the sophistication he and others have about frequency dividing networks and tuning enclosures--even if they had skills like his in woodworking.

That link mikebake put an another thread about bass reproduction is big, I think, because it says convincingly that below about 200 cycles the room is a part of the system unavoidably. That means that unless a person is going to do a room treatment and apply EQ to compensate for things the room does to frequency response that $2000 spent on subwoofers could easily be wasted.

Why not make it easier, and cheaper, for people to take a speaker with LSR technology in the mids and highs down to 35Hz or so? Or lower if they want. At that point the speaker is playing into room rise in almost all situations, and that takes the game out of the hands of the speaker designer. This compromised result is what most people end up with and live relatively happily with anyway.

If a person spends any time reading this forum it is easy to conclude that the most intractible problems people can have making speakers are in getting two drivers to work together, and Giskard often refers people back to the engineering that JBL has already done.

Why not smooth over this difficulty for the customer, make it possible to mate the LSR mid and treble to a choice of woofers and market the concept with specific instructions on a cabinet for that speaker. The manufacturer could sell some components and would have many happy customers.

It's a marvelous technology.

End of rant.

David

[4313B]

"I think a lot of people are like me in that I am not trying to cheap into the cheap sounds--I'm trying to cheap into the good sounds. And because I'm a workin' guy I think if I've got a table saw and a bottle of glue I can follow a drawing for a box. The stumbler is the crossover."

The fun part is the crossover. One has so many options available. If they have the time and tenacity to stick with it the results can be quite fantastic. As for cheap, I don't see anything cheap in doing your own R & D to come up with a viable system. It costs money and it costs time.

Ron says he is tri-amping the system, I assume with the Rane AC23. No passive filters to fret about there. When you mention bi-amping many people start sweating and fretting at the cost of a second amp. Ron is tri-amping which would send most Walmart shoppers into cardiac arrest.

"If a person spends any time reading this forum it is easy to conclude that the most intractible problems people can have making speakers are in getting two drivers to work together, and Giskard often refers people back to the engineering that JBL has already done."

I didn't realize that was a problem. Thanks for the heads up.

"Why not smooth over this difficulty for the customer, make it possible to mate the LSR mid and treble to a choice of woofers and market the concept with specific instructions on a cabinet for that speaker. The manufacturer could sell some components and would have many happy customers."

Who is going to pay for the R & D to make this happen? People already bitch and moan about the cost of raw transducers. I won't even get into their constant crying about the cost of recone kits and diaphragms. Now we want to add in the cost of the R & D necessary to make this viable? It'll never happen. The LSR32 is no L100 where you take three (well designed for the time) transducers, toss them into a bookshelf-sized enclosure and throw a couple of capacitors in series with the mid and high frequency transducers.

[4313B]

252G $234 versus 124H (1980) $180
C500G $150 versus LE5H (1980) $60
053Ti $122 versus 077 (1980) $145

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[4313B]

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[Robh3606]

Hello David


"I think a lot of people are like me in that I am not trying to cheap into the cheap sounds--I'm trying to cheap into the good sounds. And because I'm a workin' guy I think if I've got a table saw and a bottle of glue I can follow a drawing for a box. The stumbler is the crossover."

I could not agree more!! Just a reminder the site has the schematics for most of the JBL consumer speakers. I am a DIY and without the original crossovers I would be lost. I can't see anyone trying to replicate one of the clasic systems without the original crossover. You may not get the DCR on the coils right but it at least gives you a sound starting point.

"I just look at that fabulous set of speakers Ron has made there and realize that a lot of people could try it and not come out with as good a result because they do not have the sophistication he and others have about frequency dividing networks and tuning enclosures--even if they had skills like his in woodworking."

Yes they are!!! I have been into this hobby for over 30 years. Did a couple of DynaKits the SE-10 and ST-400 power amp. What a great time that was! Never did speakes till about 2 years ago. The box tunning was not to hard to deal with because of the numereous freeware such as Win Isd. The crossover was a real challenge. I run all actives now but my first cut was with passives. Took me numerous tries to get it right. Also got lots of help here.


"If a person spends any time reading this forum it is easy to conclude that the most intractible problems people can have making speakers are in getting two drivers to work together, and Giskard often refers people back to the engineering that JBL has already done."

Why would anyone ignore the engineering the manufacturer already has put in. Makes no sense to re-invent the wheel.

Rob

[speakerdave]

Giskard--"The LSR32 is no L100 where you take three (well designed for the time) transducers, toss them into a bookshelf-sized enclosure and throw a couple of capacitors in series with the mid and high frequency transducers."

I think that's my point. The crossover is in many ways the sine qua non and it's very difficult to do well. Most people do not have the necessary understanding of passive networks and going into the projects they don't understand the necessity of it.

In JBL's component catalogue of 1976 there is a chart of woofers, midranges, compression drivers and tweeters and the crossovers that bring them together in different combinations. They could do it again.

David

[speakerdave]

Giskard: "I didn't realize that was a problem. Thanks for the heads up."

It's not a problem. I should have added that you remind us not to try and outsmart JBL engineers if they've already worked on a particular combination and the solution is available.

I think you've also said if refurbishing or copying a speaker use the original crossover with bypasses, if building from scratch the way Ron did, go bi- or tri- amp. I was agreeing with all of these ideas (I thought). But even in multi-amplifier setups some supplementary tailoring of the filter must be done.

Thanks for the comparison price chart on the drivers. It is an eye-opener.

Regards,

David

[4313B]

"It's not a problem. I should have added that you remind us not to try and outsmart JBL engineers if they've already worked on a particular combination and the solution is available."

Only because doing so will require some degree of effort. Anyone can plug and chug through a few formulas and come up with a "solution". Whether that "solution" will sound decent or not is another story. I have no doubt there are plenty of people out there today that can come up with a better solution than an old LX80 or N7000.

"In JBL's component catalogue of 1976 there is a chart of woofers, midranges, compression drivers and tweeters and the crossovers that bring them together in different combinations. They could do it again."

Yep, in 1980 you could buy the S300-1 component system (136H, LE85/HL92, 077, LX300) for $915 and the EN5C enclosure for $250 for a total of $1,165 or you could simply go out and buy an L300 for $1,395 and get an arguably better looking system. (The 4333BWX was $1,275 and I'd spend the extra to get the blue baffle )

[speakerdave]

So custom speaker building will always be the domain of the resourceful, ingenious, intelligent, agile maverick--


Works for me!

[4313B]

Hmm, I hope that my propensity for playing the devil's advocate isn't discouraging.

Originally posted by speakerdave
So customn speaker building will always be the domain of the resourceful, ingenious, intelligent, agile maverick--

Or for those who just want to have fun. It can be taken to any level one wants to take it to. I certainly don't allow my lack of resourcefulness, agility, ingenuity, and intelligence get in the way of my fiddling with legacy JBL componentry.

I'd like to check out Ron's system to see how it sounds using the active filter instead of the passives.

I'd like to hear the LSR32 components in a vertical array with a good 1st or 2nd order Butterworth passive filter.

[Ian Mackenzie]

I see some interesting view points here.

For me and perhaps many others I think the whole thing here on the Lansing Heritage Forum is more about building/restoring the vintage legend systems we recall from our youth/ hi fi hey days, and its a great hobby.

The vintage 4315/4343/4345 are classic designs and would appear to be a vintage builders dream and certainly offer the results and satisfaction.

Some of us are approaching the cross roads of restoring/ building vintage JBL systems (using original schematics & parts) while also contemplating the proposition of building state of art diy systems using the latest hi end JBL parts......

Thats a whole new ball game, more expensive, hi risk and requires different resouces, skills and experience. Playing around with exotic crossover capacitors is the tip of the iceberg.

Rolling you own passive crossovers can be fun, but does requires some basic technical knowledge and test equipment and lots of trial & error and evaluation.

I use an inductance meter for the adjustng coils, a diy calibrated mic, & sound card solftware called Winairr which is available from places like Audio Express.

Good results can be obtained by adjusting your test book schematic values until you get a fairly smooth response, then use your ears.

If you want to can take the plung, buy expensive optimiser software like Speakereasy, Linear X, Calsod which is a fancy way of figuring out the crossover values. But if you can afford to do that you may as well just go and buy a great off the shelf system thts been de bugged.

Alternatively to avoid massive frustration and disappointment you may you want look at the latest proven hi end diy designs published on the www (see speaker builders home page) prepared by skills engineers and enthusiasts.

Ian