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View Full Version : What should I use as rear speakers in surround sound?



HemiMoparGuy198
12-12-2008, 12:20 AM
Hi All,

I currently have some equipment that I want to set up in a surround sound system. I need some ideas as to what else to use. I have a pair of JBL 4647A (incase any don't recall to save from looking up is essentially 4507 Cabinets with 2226 speakers ) with 2380A horns on top with 2445J drivers. I want to use these as my front mains in my surround sound set up. Does anyone have any suggestions as to what I should use for rear speakers and a center, also a subwoofer? Any help or ideas will be greatly appreciated, thank you in advance

Eric

Allanvh5150
12-12-2008, 12:32 AM
Hi Eric,

Welcome to the forum! Chrysler and JBL, hmmmmm. You should get a lot of replys on this one. There is not a lot of content in the rear channels so you dont need mammoth cabinets back there. I used to run E20's for rears which I considered adequate. Now I run L150's but they dont do much at all. I am currently working on a dedicated cinema room and I will be using a pair of L86's recessed into the wall. As for a center, most of the other forum members will say that you should use the same as the main left and right channel. I am of a slightly different school of thought there. I will be using a 2202 and a 2370/2425 which I consider very good for voice and lets face it, most of the center is filled with voice and the mains are more for sound effects/music. As for a sub, the sky is the limit. How much room do you have? That is my angle on it. You will get other answers of course but the guys here are very knowledgable and you will get what you are looking for.:)

HemiMoparGuy198
12-12-2008, 08:40 AM
TY. Yeah, Chrysler and JBL, kinda funny, I was introduced to JBL by Chrysler. When I was 13, my parents bought a Dodge Intrepid when they first came out. It was decked out with the Infinity Sound System, which to me sounded excellent. WAY better than the Cadillac's with the Bose Systems.

So I did a bit of research and found that Infinity was owned by Harman International as well as JBL and many others. I bought some Infinity speakers for my car, cuz the specs were best for car audio out of any of the owned companies.

Then I started getting into home audio and did researching and had an awesome HT system picked out with Infinity speakers. However, a brand new cinema opened up near by and we went to a movie and it sounded SWEET, I noticed they were JBL speakers, which brought me to the urge to research JBL more, and found JBL PRO.

So I've had a JBL Pro system all picked out but comes to over $20,000. I was shopping for some speakers for my DJ system and got a great deal on the 4647's. Then after some recent research, found they are cinema speakers, so I decided to move them up to the living room, and now am looking for the best way to complete the system.

JBL 4645
12-12-2008, 08:54 AM
Oh, one of these haven’t seen a JBL 4647A in years now.
http://www.cinematech.info/manuals/Sound/Speakers/JBL/pub/cinema/4647a.pdf (http://www.cinematech.info/manuals/Sound/Speakers/JBL/pub/cinema/4647a.pdf)

Well that should be obvious you should get a JBL 8330A or 8333 or 8340.

http://www.jbldealer.com/images/cinema/8330.gif

http://www.bhphotovideo.com/images/items/395376.jpg
http://www.jbldealer.com/images/cinema/8340.gif

HemiMoparGuy198
12-12-2008, 09:00 AM
So you feel L150's are over kill for rears? I have heard that many people run the same speaker for center as the front L+R. But I can't help but wonder how this works out. I know some people may have a projector and what not, but most I'm sure are like me, I have a 55" widescreen sitting on a nice oak TV stand. Having a third 4647/2380/2445 in the center would block the TV as well as the cable box and DVD player. My setup is angled in a corner of the room, so it COULD fit back there, but I see the mass of the TV and stand and such reflecting the sound too much and will be slightly out of phase. As far as Subs, I don't exactly have much room now, but I would still want to get them for when I will have a bigger living room or cinema room, even if they sit in the basement until I move. I want the most bass possible, but don't want it to over power everything else

Slare
12-12-2008, 09:00 AM
Edit: JBL beat me to it, but the 83 series seems like a good surround fit.

That's a lot of horsepower for a home environment. It's just my 0.02 but there aren't really many "typical" purpose-designed center channels that will keep up.

As noted above you'd ideally want a center that is as similar as possible, which in this case seems impossible due to size issues. My first recommendations would be to use no center or consider building one with same HF solution a single or pair of downsized LF driver(s) with similar crossover points.

But if you have a big room (which hopefully you do!) the high output and good dispersion of the horns will probably make things sound just fine without a dedicated center channel.

Most people are less picky about the surrounds but if you'll want something pretty beefy to keep up. I'd consider 8330A / 8340A's or something similar. Earlier models of similar construction can be found quite affordably on ebay and similar outlets from time to time. I recall seeing a couple pairs of speakers matching the 8340's construction go for less than a couple hundred.

JBL 4645
12-12-2008, 09:18 AM
Hi Eric,

Welcome to the forum! Chrysler and JBL, hmmmmm. You should get a lot of replys on this one. There is not a lot of content in the rear channels so you dont need mammoth cabinets back there. I used to run E20's for rears which I considered adequate. Now I run L150's but they dont do much at all. I am currently working on a dedicated cinema room and I will be using a pair of L86's recessed into the wall. As for a center, most of the other forum members will say that you should use the same as the main left and right channel. I am of a slightly different school of thought there. I will be using a 2202 and a 2370/2425 which I consider very good for voice and lets face it, most of the center is filled with voice and the mains are more for sound effects/music. As for a sub, the sky is the limit. How much room do you have? That is my angle on it. You will get other answers of course but the guys here are very knowledgable and you will get what you are looking for.:)


I disagree with you. The surrounds in principle was designed as an effects ambient channel in the old days. Over the course of years the content as gotten somewhat larger in the low end and depending on the film mix on some there is a heavy dynamic range that can bite you in the ass.

I’ve ran a few tests and have found a few films that have low end below 80Hz and even 50Hz and some even down to 30 and 25Hz, now then.

LCR or L Lex C Rex R with the Todd-AO 70mm process used five screen with discrete tracks of information so you’ll have centre for most but it can go anywhere to tell the story. It can be hard panned or half panned or centralized.

Yes today it’s common to hear dialogue anchored to the centre with little or no dialogue panning. You need matching LCR fronts or you can even distract the half panned effects from most films with a little Dolby stereo matrix technique with existing Dolby digital 5.1 discrete. Never ever mismatch the fronts unless you what your sound to be rubbish, doesn’t matter if your using small JBL loudspeakers in the home never ever mismatch.

HemiMoparGuy198
12-12-2008, 09:34 AM
My room is an OK size about 16ft by 16ft. But I won't be living here but for a few more months, so I will soon have a much bigger room.

Now I'm starting to consider when I upgrade to a plasma TV or projector, something that can be on the wall and doesn't need a TV stand, that I could build a cabinet that sits horizontally under the screen. And drop in a 2202 in the center of the cab and a 2370/2425 on each side of it (the same speakers that Allanvh5150 suggested) or possibly the same cabinet I described with the same model speakers I already have. But according to Allanvh5150, the 2370/2425 would be better for voice and such. And if it is true that center is mostly dialouge, is a 15" woofer really neccesary?

HemiMoparGuy198
12-12-2008, 09:53 AM
Oh, almost forgot, also need ideas for a crossover setup for the 2380/2245. Because these are screwed to the top of the 4647's. I do plan to build an enclosure around them, but right now they are attached with L brackets. They came this way when I bought them, with no corssover. And according to some research (in other forums) a whisper over 500 Hz will fry the coil in the horns, so I need a way to avoid this for when I replace the diaphragms

JBL 4645
12-12-2008, 10:46 AM
Oh, almost forgot, also need ideas for a crossover setup for the 2380/2245. Because these are screwed to the top of the 4647's. I do plan to build an enclosure around them, but right now they are attached with L brackets. They came this way when I bought them, with no corssover. And according to some research (in other forums) a whisper over 500 Hz will fry the coil in the horns, so I need a way to avoid this for when I replace the diaphragms

Quote from “Life With THX In Hollywood Part 1” (in-70mm)

The most common problem is a damaged high-frequency driver. If this happens to the center channel, you can lose all intelligibility of dialogue and may have to shut down to replace it. (Virtually all dialogue comes through the center channel.) The most notorious recent event like this happened next door at the Chinese Theatre (thank God!), during the invitational premiere of Schwartzenegger's "Eraser". A loud sound of some sort, in the middle of the film, burned out the high frequency driver of the center channel. Dialogue was totally muffled, being heard only through the low frequency (below 500 Hz) components of the center channel.

Full article part 1
http://www.in70mm.com/newsletter/1997/51/thx/index.htm

Part 2
http://www.in70mm.com/newsletter/1998/52/thx/index.htm

Allanvh5150
12-12-2008, 11:19 AM
I disagree with you. The surrounds in principle was designed as an effects ambient channel in the old days. Over the course of years the content as gotten somewhat larger in the low end and depending on the film mix on some there is a heavy dynamic range that can bite you in the ass.

I’ve ran a few tests and have found a few films that have low end below 80Hz and even 50Hz and some even down to 30 and 25Hz, now then.

LCR or L Lex C Rex R with the Todd-AO 70mm process used five screen with discrete tracks of information so you’ll have centre for most but it can go anywhere to tell the story. It can be hard panned or half panned or centralized.

Yes today it’s common to hear dialogue anchored to the centre with little or no dialogue panning. You need matching LCR fronts or you can even distract the half panned effects from most films with a little Dolby stereo matrix technique with existing Dolby digital 5.1 discrete. Never ever mismatch the fronts unless you what your sound to be rubbish, doesn’t matter if your using small JBL loudspeakers in the home never ever mismatch.

We can always agree to dissagre. As you said there are a few movies with low content in the surrounds. I dont play a lot of movies but ai am yet to find one that makes my rears of surounds do much of anything. As fot the centre, Jbl mismatch them all the time is thier own systems. You would be very surprised how a centre channel with a horn will sound. You are invited round anytime for a listening test, I am sure you will be far from dissapointed.:)

JBL 4645
12-12-2008, 11:28 AM
We can always agree to dissagre. As you said there are a few movies with low content in the surrounds. I dont play a lot of movies but ai am yet to find one that makes my rears of surounds do much of anything. As fot the centre, Jbl mismatch them all the time is thier own systems. You would be very surprised how a centre channel with a horn will sound. You are invited round anytime for a listening test, I am sure you will be far from dissapointed.:)

LOL thanks but down under is low way to travel besides that’s why the Empire was invented with JBL in mind if I want perfect that is second to none I’d go to London.

HemiMoparGuy198
12-12-2008, 11:34 AM
Sweet, look what I started!!:biting:

JBL 4645
12-12-2008, 11:38 AM
I forgot which cinema it was that was looking at this year, I think it was in Japan and they had large stage speakers fitted in the sidewalls and rear wall for the surrounds. So I guess the same speaker was used for stage?

I’d have to find the picture but where I can’t remember what keyword I used??

JBL 4645
12-12-2008, 11:40 AM
Sweet, look what I started!!:biting:


What? Are you currently on any prescription medication? What’s with the biting smiley?

HemiMoparGuy198
12-12-2008, 11:50 AM
So anyway guys, I think I am sold on 8340's or the like for surrounds. I want to try to stick with JBL PRO stuff vs mixing PRO with Home equipment. But still need ideas for crossovers and subs. And article was posted about THX active crossovers...but I pretty much know (without any research) I can't afford that...not yet anyway. When I build my new house a few years down the road, I will have a Home Cinema, built pretty much just like a that of a true cinema. Maybe not quite as big of screen, and definitely not all the seating...but as far as sound system, I want it to be VERY comparable. But until then I'd like to keep it on the inexpensive end, thus going with vintage equipment.

I am strongly considering using active crossovers (typically less resistive, thus less compromising the sound, no matter how minimal.) But, JBL does make speakers with passive crossovers, so I was also considering those. Ideas?

As far as subs, like I said, not all that much room right now, and the size of this house, I'm sure the 4647's will roar PLENTY of bass, but I still want ideas so I can get them and whatnot for when I get a bigger house.

Thanks for the great ideas so far. Even though there are completely contradicting opinions on the center. I think price and availability will be the huge deciding factor for my center.

HemiMoparGuy198
12-12-2008, 11:53 AM
What? Are you currently on any prescription medication? What’s with the biting smiley?

I'm not sure, just kinda picked one. Medications, no, but prolly should be. The fiance is in college for Psychology, and keeps demanding extra credit for her live-in case study. HEHE :D

JBL 4645
12-12-2008, 11:59 AM
I'm not sure, just kinda picked one. Medications, no, but prolly should be. The fiance is in college for Psychology, and keeps demanding extra credit for her live-in case study. HEHE :D

Well there is opportunity to eat rat today and put all income on JBL while eating delicious tasty rat for breakfast lunch and dinner while listening to JBL and drinking rats blood as if it was vintage red wine. :bouncy::D

hjames
12-12-2008, 12:09 PM
Well there is opportunity to eat rat today and put all income on JBL while eating delicious tasty rat for breakfast lunch and dinner while listening to JBL and drinking rats blood as if it was vintage red wine. :bouncy::D

You, my friend, are FAR too serious about all of this today ...

I think you need to have some eggs with that ratburger ...
give it a bit of a rest, eh :D

Save some for sooty~!

HemiMoparGuy198
12-12-2008, 12:14 PM
LOL

JBL 4645
12-12-2008, 12:50 PM
You, my friend, are FAR too serious about all of this today ...

I think you need to have some eggs with that ratburger ...
give it a bit of a rest, eh :D

Save some for sooty~!

See that’s the trouble when I eat rat burger it gives me so much energy…:bouncy:
He’s so large now because of all, the Dorset rat I’ve been feeding him on.
:D

Anyway back to JBL those 8340 are priceless most of the large screens at the West End use them thou the Odeon screen LSQ is somewhat undesirable. The Empire screen 1, now that rocks with clear easy focus on directional stereo surround effects. Find a US supplier that has second-hand reconditioned JBL cinema PA speakers, there are plenty of them around.

HemiMoparGuy198
12-12-2008, 01:06 PM
Funny...Demolition Man was the first thing I thought of when you started rambling about eating rat

HemiMoparGuy198
12-12-2008, 01:57 PM
No ideas for crossovers or subs?

JBL 4645
12-12-2008, 02:27 PM
I would go with loudspeaker management crossovers systems there new word, now the old ones great in there day and still are expect the user now what’s control and flexibility as well as safeguarding their investment.

There are many models on the market now to choose from? Each has high price tag attached. One of the best if you won the national lottery is dbx4800 as used in the famous Empire Leicester Square London screen 1 THX 56KW.

Others from BSSaudio, BBE, Behringer, dbx I like a few others on this site use Behreinger DCX2496 a few others use dbx but there is higher cost with dbx and higher perigee to match it as well.

BSSaduio
http://www.bssaudio.com/crossovers_loudspeaker.php (http://www.bssaudio.com/crossovers_loudspeaker.php)
BBE
http://www.music123.com/BBE-DS48-4-Input---8-Output-Digital-Loudspeaker-Management-Processor-180941-i1168879.Music123 (http://www.music123.com/BBE-DS48-4-Input---8-Output-Digital-Loudspeaker-Management-Processor-180941-i1168879.Music123)
dbx
http://www.dbxpro.com/products.php (http://www.dbxpro.com/products.php)
Behringer
http://www.behringer.com/dcx2496/index.cfm?lang=ENG (http://www.behringer.com/dcx2496/index.cfm?lang=ENG)

The idea is for the unit with all in one is to monitor the audio signal. It can be user custom tailored to suit the loudspeakers with assorted use of Butterworth, Bessel, and Linkwitz-Riley from -6db -12db -24db and -48db. The units come with: parametric, EQ Dynamic EQ, audio limiter – for protection against harmful peaks.

Distance time correction, (automatic or manual) phase polarity correction and temperature operation.

For 5.1, installation at least two (DCX2496) for hyper use at least four or more. The units support three channel input with six outputs. The dbx supports up to 4 channel input and 8 channel output.

Not to mention multiple amplifiers stereo per channel LCRS sub bass and the cost will soon sky rocket. To give you an idea Empire Leicester Square’s JBL dbx crown installation was £250.000 grand (2006). So get saving now. :D

There’s a lot of discussion on the Electronic Crossovers forum. Would you like to know more?
http://www.audioheritage.org/vbulletin/forumdisplay.php?f=66 (http://www.audioheritage.org/vbulletin/forumdisplay.php?f=66)

HemiMoparGuy198
12-12-2008, 03:06 PM
Correct me if I am wrong, but the few of those I looked at the manuals for, basically seem like REALLY fancy ones of these

http://www.musicresourcesusa.com/music_effects_resources/manual/crate%20pro%20audio/ls4-xo.pdf

I have a couple of these laying around from my DJ system, will they work well for my application to save a few $$ right now?

JBL 4645
12-12-2008, 04:13 PM
That’s a nice crossover.:)

Basically they are fancy but more much more I’d use (Google Product search) on your side of the world and look around for the lowest prices size up the lowest and then buy, buy, buy, “no prisoners

The diagrams are cool and easy to understand unlike the Behringer manual its like frigging world atlas in a foreign language, takes at last 10 reads, :banghead::D but once you’ve figured it out its easy.

HemiMoparGuy198
12-12-2008, 04:54 PM
I've used a couple of these Crate crossovers for a while now with my DJ/karaoke set up. They seem to work great to me. I think for now I am going to use them for my HT setup and wait to get the DBX 4820 when I build my house with cinema room.

Any ideas for subwoofers? I was thinking a 4642 or similar. Will that suffice, is it WAY too much for my application right now?? Any other ideas, suggestions or comments about subs?

Thanks

JBL 4645
12-12-2008, 05:01 PM
I've used a couple of these Crate crossovers for a while now with my DJ/karaoke set up. They seem to work great to me. I think for now I am going to use them for my HT setup and wait to get the DBX 4820 when I build my house with cinema room.

Any ideas for subwoofers? I was thinking a 4642 or similar. Will that suffice, is it WAY too much for my application right now?? Any other ideas, suggestions or comments about subs?

Thanks

Yeah sure the frigging cost have any idea how much those subs are each! I’d make sure you have least 1K and look real hard for the lowest price on (Google Product) two would be suitable for small room in will placed position. a good few KW to run them separately.

Oh, you have the 4820 in mind still a few grand, what are rich? :D

HemiMoparGuy198
12-12-2008, 05:11 PM
Oh, you have the 4820 in mind still a few grand, what are rich? :D

Not yet, but will be. Gotta finish my Electrical Engineering degree and the fiance has to finish school, either psychology or med school, she hasn't decided. Plus all the money I will save by building the house myself, since I own a construction company...but that isn't doing so hot right now since the economy SUCKS and no one can afford new houses. Gotta spend the money some where, and I've always wanted a BAD ASS home theater.

HemiMoparGuy198
12-12-2008, 06:43 PM
Found some JBL 4628B for $160 for the pair. Is it worth it, and would it be anything I could use for the setup I am wanting?

toddalin
12-12-2008, 08:21 PM
Found some JBL 4628B for $160 for the pair. Is it worth it, and would it be anything I could use for the setup I am wanting?


If it all works, its a steal!

While not suited to home playback as is, they could easily be modified for such use by retuning the cabinets and revising the crossovers.

You would be hard pressed to find the pair of tweeters for that price. In fact, buy them and if the tweeters work, I'll send you $160 for the two tweeters and you can keep the rest (15" and 8") gratis or to resell! ;)