How to build a home theatre around L300s

[TGK]

Hello,
I'm new and way over my head re: much of the science and engineering discussed here, but I like to think I appreciate quality and know when I need advice. So thanks in advance.

I'm the second owner of a pair of JBL L-300s that I bought in 1978. They have been and still are magnificent. With the exception of a woofer that JBL replaced a few weeks before the warranty expired (really!), they have been flawless.

Now I want to build a 5.1 home theater system around them as the front speakers. I need help to select the other speakers to work well with and complement them. I have seen several ads for L-300s listed at $4000. This is not the price ballpark I'm playing in. I know how fortunate I am to have these speakers, but I also have to work with a moderate budget. Also, advice on a receiver would be appreciated as well. Thank you.

[Chas]

I am by no means highly HT experienced, but I will relate something that happened to me. I set up a pair of 4430's for use as front L/R speakers and built my own center channel using a 175DLH and a pair of 6" woofers. For the rear I was using a pair of Camber bookshelf speakers.

Everything was fine until I tried to set up my mid level Sony ES receiver to balance all the channels. It was then that I discovered that the receiver couldn't compensate the level enough for the lack of effeciency of the rears.

Caveat emptor, try to find a close match to your L300 effeciency rating (i.e.~94-96db) for your rears. FWIW, I always thought a pair of 4425's would make nice surrounds, but I have never seen any for sale up here.

Good luck.

[jcrobso]

You need to keep the sensitivity of the speakers as close as possible.
I have JBL loaded K-horns for the front, JBL Nova L88's for the rear and JBL EC35 for the center. Fortunately my JVC receiver has the ability to handle the 10db difference between the speakers.
I don't use a sub so I have 5.0 system, the D140F loaded K-hons do a great job on the bass and I can run my surrounds full range because of the 12" woofers in the L88 Nova. I get lots of bass from all around instead of just from one place. The EC35 does a good job for the center, but I am also considering making my own center using larger JBLs. I like the idea of LE175 for the center!
My suggestion: is to get a L100 or any variation there of for the center and even do the same for surrounds.

[Mr. Widget]

Now I want to build a 5.1 home theater system around them as the front speakers. I need help to select the other speakers to work well with and complement them. I have seen several ads for L-300s listed at $4000. This is not the price ballpark I'm playing in. I know how fortunate I am to have these speakers, but I also have to work with a moderate budget. Also, advice on a receiver would be appreciated as well. Thank you.

Many here, myself included, would whip up a custom center channel using parts similar to the L300s... this sort of thing isn't a trivial undertaking though and every time I start a new project, even with over 30 years of experience designing and building custom and DIY speakers, there are no guarantees that it will work out as desired.

I'd suggest you buy a proper center channel, a good receiver, and a pair of competent surrounds. My first choice in centers would be the 880 Array, but it is likely too expensive for this project, you might consider the new JBL LS Series... I've recently listened to the LS80 floor standers and am happily impressed. (More to come on this later.) In the LS Series there is an affordable center chanel that should do an admirable job of keeping up with the L30s. For surrounds, the Performance Series P520WS surrounds are quite affordable and are a bargain.

As for a receiver, I'd go with a mid level Denon or Onkyo/Integra.

I noticed, you didn't mention a sub. Personally I'd add one or two, but I suppose you could get by with the L300s at least at first.


Widget

[robertbartsch]

HT is tricky - trust me!

The center channel in a HT is probably the most important but ideally all the speakers should match or at least the sensativities should be close. Obviously, the best choice for the center would be another L300.

Since the cost of an L300 is prohibited for you, there are a few other options that you might consider.

1. I suppose you could buy a single JBL SR4725/4735 on Fleabay for under $500 and mount the components in a furniture grade cabinet.

2. Buy a single L100 or other equivalent JBL 12" system

3. Buy JBL components and build your own cab.


In one HT in my home, I bought an empty L100 cabinet and mounted a 12" 2206 and small horn with a 2425 compression driver and crossed it at 1200hz. Some minor carpentry work was necessary but the project turned out well. Cost was under $500 with used components.

[toddalin]

Center (L300 components) and sub (W15GTi) in one (split) cabinet.


Front and rear surrounds use W10GTis with 2425Js on aftermarket butt cheeks. These are about 11 dB less efficient than the L300s (horns needed lots of padding), but my Yamaha has no problems with that. These will give real bass in a small (~1.5 cu ft) package.

[TGK]

Well, that's a lot to chew on. I have a question about the sub-woofer. I thought that a 5.1 receiver required five speakers in order to properly decode the content, but Mr. Widget (great handle) suggests it is optional. Even if I didn't need it for the bass, don't I need it to have the system perform as it should? The speakers, to my ears, have great bass as is, but I assumed I would be adding a sub-woofer. Thanks so much.

John

[Mr. Widget]

I have a question about the sub-woofer. I thought that a 5.1 receiver required five speakers in order to properly decode the content...

All of the better surround receivers and processors have bass management that will divert the LFE information to your front two loudspeakers if you feel that they are adequate.

An argument could still be made for the addition of a sub, but a decent sub will burn through another grand... perhaps money better spent on the receiver and center channel loudspeaker.

There are actually many variables. The room, the layout of the room, the number of listener/viewers, budget... these all will skew the relative importance of the numerous variables.


Widget

[robertbartsch]

The JBL professional series cinema sound systems provide EXCELENT value; see link below.

http://www.jblpro.com/catalog/Genera...x?PId=71&MId=1

[jcrobso]

Most AV receivers 5.1, 7.1 etc have a line output for separate self powered sub. They only supply power for the other speakers. When I configured my AV receiver I set it up for no sub and the fronts and surrounds as large speakers and the center as a small speaker.
My room is 14'X17' the K-horns have excellent bass and take up two corners on the 14' side with the HDTV in the middle. My L88s are mounted up on the back wall behind the seating area. With two 15" speakers and two 12" speakers I have not felt the need for a sub.

[grumpy]

The JBL professional series cinema sound systems provide EXCELENT value

FWIW, system in link [3677] appears to be NLA, but street price was $600/ea

no approval or criticism implied or intended, just additional info.

[hjames]

I'm running a pair of JBL 4341 monitors with a Harman Kardon AVR7300 receiver I bought used.
(I run them biAmp now, but I have run them directly off the receiver).
That receiver will do stereo mode or 5.1 mode (even 7.1) depending on how I set each source, and has 125w/ch x 7 !!

When I run it in Home theatre 7.1 mode for movies or TV, I run the monitors as front left and right,
then use smaller vintage JBL L20T speakers for side and rear surround. They cost me around $120/pr.
I DID buy a nicer JBL LC2 for use as Center, and have used the system both without a sub, or with a separate JBL B380 15 vintage sub. The sub is nice to have for movies that have extra bass sounds, like action/adventure films, but you can live without it. That particular sub needed its own amp.

You'll find side and rear surround speakers aren't as critical as what you run in the front ...
I mean, its really NICE to have matched speakers all around -
but if you are on a budget, you can cut back on the cost of your surrounds.

I mean - you have the L300s - get a really nice receiver, buy a really good center speaker, and scrounge a bit for the surrounds. You can always upgrade surrounds later if you need to, right?

[toddalin]

With two 15" speakers and two 12" speakers I have not felt the need for a sub.

When you truley feel a sub, you will feel the need for a sub.

[hjames]

When you truley feel a sub, you will feel the need for a sub.

Nah, its like G-man says ... its a price-point thing.
When you truly have money to burn on a high end sub, you'll buy a sub.

Remember, the original poster said they were building on a budget!

John has 2 15s in that pair of L300s, he can always add a sub LATER.

[robertbartsch]

I was very surprised at how well a dedicated powered sub-woofer worked in a HT. Basically, IMO there is not that much super low (ULF) sonic material in DVD music sound tracks that comes into play often.

However, HT is different. I would say many if not most HT cinema sound tracks from movies contain a fair amount of sub-bass sonic material that provides life-like realisim to airline take offs, trains, buses, bombs, earthquakes, title waves, etc.

Your center channel should be your next project but in the future, if you have some free coin, you should consider a dedicated powered sub-woofer.