Tony Reed Posted August 14, 2002 Share Posted August 14, 2002 I purchased a pair of the JBL 4648A-8's some time ago. There are 5 bolts in the top of each cabinet. I seem to remember some discussion about what mounts to the top of these things. I can't find the thread, does anyone remember? Thanks, Tony Quote Link to comment Share on other sites More sharing options...
TBrennan Posted August 14, 2002 Share Posted August 14, 2002 Tony---The treble horn and driver attatch there, the 4648 is normally used as the woofer bin in a 2-way motion picture theater speaker with a compression driver and horn used above 500hz. www.chicagohornspeakerclub.org Quote Link to comment Share on other sites More sharing options...
Tony Reed Posted August 14, 2002 Author Share Posted August 14, 2002 Is there a specific horn for these things? I'm in the market for a pair of whatever fits these things? Thanks, Tony Quote Link to comment Share on other sites More sharing options...
space_cowboy Posted August 14, 2002 Share Posted August 14, 2002 I've got the 4638 and wonder if the bolt pattern is the same as the 4648? I'm sure the price of the other horn/driver is WAY out there, but am curious. I can't imagine what you guys do with two of those, my single one earned me a noise violation ticket a couple of months ago...LOL. Mark ------------------ Turntable - Pro-Ject 2.0 Phono Preamp - Parasound PPH-100 Receiver - H/K AVR-210 DVD - Sony DVP-S360 TV - RCA 31" Mains - KLF-20 Center - KLF-C7 Surrounds - Optimus Pro LX-10 Sub - Yamaha YST-SW160 Reinforcement - JBL 4638 Quote Link to comment Share on other sites More sharing options...
Tony Reed Posted August 15, 2002 Author Share Posted August 15, 2002 OK... How about suggestions as to what horn and driver would be a good compliment for this beast. I could go 2-way or 3-way. Suggestions, please. Tony Quote Link to comment Share on other sites More sharing options...
kenratboy Posted August 15, 2002 Share Posted August 15, 2002 Yes, the bolts are for a horn. My Chevy has a 4-bolt main, so can I put a horn on that? Yeah, about $1000 for EACH channel of horns. Seriously, look at the 4000 Series cinema speakers on jblpro.com, use the smaller of the horns and drivers, it will make your ears bleed reguardless. If you want 3-way, and have to buy reatail, like $5,000 with amps. Toys this stuff ain't ... Big tools for big jobs. SUGGESTION: Use a pair of small Klipsch or JBL speakers X'ed over at 60 or 80 Hz, and use the 4648 cabs as the subwoofers. Thats what I do, ENDLESS volume. My 6.5" woofers have turned into 6.5" midranges and my tweeter was ment for a much bigger system, so in my room, I think 110 dB. full range is very possible. I now have a 3-way system (sort of) with a 15" woofer, 6.5" midrange, and a horn tweeter. All in 1500 cu. ft. GO TO THE SITE IN MY SIGNATURE!!! That is where to get real JBL Pro info. I am also kenratboy over their. ------------------ Receiver: Sony STR-DE675 CD player: Sony CDP-CX300 Turntable: Technics SL-J3 with Audio-Technica TR485U Speakers: JBL HLS-610 Subwoofer: JBL 4648A-8 Sub amp: Parts Express 180 watt Center/surrounds: Teac 3-way bookshelfs Yes, it sucks, but better to come. KLIPSCH soon! My computer is better than my stereo! For JBL related subjects and more fun, click: http://www.audioheritage.org Quote Link to comment Share on other sites More sharing options...
TBrennan Posted August 15, 2002 Share Posted August 15, 2002 Tony---Use a 2446 2" throat compression driver. Pick the JBL 2" biradial horn that meets your dispersion needs. CD horn EQ is needed. But for home use you can do better than the stock JBL theater treble system, good as it is. You could put that 2446 on an Edgar 350hz "saladbowl" tractrix horn for one and use a Fane horn tweeter if you want a little extra zing. Or.....oh Hell Tony, I can think of a several top ends that would sound good. www.chicagohornspeakerclub.org Quote Link to comment Share on other sites More sharing options...
kenratboy Posted August 15, 2002 Share Posted August 15, 2002 Tom, tell me about the X-over needed for a 2-way system like we are talking about. I am VERY curious. ------------------ Receiver: Sony STR-DE675 CD player: Sony CDP-CX300 Turntable: Technics SL-J3 with Audio-Technica TR485U Speakers: JBL HLS-610 Subwoofer: JBL 4648A-8 Sub amp: Parts Express 180 watt Center/surrounds: Teac 3-way bookshelfs Yes, it sucks, but better to come. KLIPSCH soon! My computer is better than my stereo! For JBL related subjects and more fun, click: http://www.audioheritage.org Quote Link to comment Share on other sites More sharing options...
Tony Reed Posted August 16, 2002 Author Share Posted August 16, 2002 What about using a 511 or 811 horn on top of this thing? Anybody think that would sound decent? Tony Quote Link to comment Share on other sites More sharing options...
IndyKlipschFan Posted August 16, 2002 Share Posted August 16, 2002 I agree a Heresy 1 would rock really nice.... Get all the clearity of Klipsch...and the solids of JBL.. Look on ebay for a great pair 300-600 dollars usually and get a great x over.,..and a good amp and Rock N Roll will be incredible. Quote Link to comment Share on other sites More sharing options...
kenratboy Posted August 16, 2002 Share Posted August 16, 2002 I mean, get a 60 Hz - 20 KHz speaker, and let JBL pickup the botton end. Like a SUPER SUPER SUPER sub/sat system. ------------------ Receiver: Sony STR-DE675 CD player: Sony CDP-CX300 Turntable: Technics SL-J3 with Audio-Technica TR485U Speakers: JBL HLS-610 Subwoofer: JBL 4648A-8 Sub amp: Parts Express 180 watt Center/surrounds: Teac 3-way bookshelfs Yes, it sucks, but better to come. KLIPSCH soon! My computer is better than my stereo! For JBL related subjects and more fun, click: http://www.audioheritage.org Quote Link to comment Share on other sites More sharing options...
TBrennan Posted August 16, 2002 Share Posted August 16, 2002 Tony---I think Altec 802, 806 or 902 drivers on 811B horns crossed at 800hz would sound very nice with the 4648s, the same drivers on 511 horns and crossed at 500hz would sound a little better, just a little. I've meant to experiment like this with my 4648s but moving the 825s out of the way and the 4648s into position is lots of work, turns it into a "thought experiment". Quote Link to comment Share on other sites More sharing options...
TBrennan Posted August 16, 2002 Share Posted August 16, 2002 Ken---Crossovers are a complicated subject. Easiest thing to do would be to do a simple 1st order (6db per octave) crossover. That means one capacitor for the compression driver and one coil for the woofer, doesn't get any simpler. Altec 800 and 900 series drivers will work with 500hz 1st order crossovers, no other high performence compression drivers I'm aware of will. There are tables online that will give you the value of the components needed. Like for a 500hz high-pass, 1st order, with a 16 ohm driver the cap value is either 40 or 20 microfarads, I forget which. Now the crossover is more accurate if you know the ACTUAL impedence of the driver at the crossover frequency not just the nominal impedence. However Altec drivers work pretty well figuring by the nominal impedence. For the JBL boxes you can look at the impedence curve on the spec sheet to find impedence at the crossover frequency. So you find a chart with the values and frequencies and figure what cap and coil you need. Oooh! The Parts Express site has such a chart, you know them. Best place to order the crossover parts from anyway. Yeah, read up there Ken. And don't forget, you'll need an L-Pad to dial doen the compression driver and balance it with the woofer, it's several db more effficient. If you have the amps the easiest and best way is to use an active crossover and bi-amp, then you just set the dial for 500hz or 800hz or whatever. Four channels of amplification and an active crossover are great tools for the horn experimenter, they make things SO much easier. www.chicagohornspeakerclub.org Quote Link to comment Share on other sites More sharing options...
kenratboy Posted August 16, 2002 Share Posted August 16, 2002 I agree Tom. A $400 Rane active X-over and some amps (hell, tubes for HF, SS for LF!!!) would be too much fun. All the experimenting. Hmmm, can a tweeter play a 20 Hz note at 110 dB.? Let's find out... Click, POP! ------------------ Receiver: Sony STR-DE675 CD player: Sony CDP-CX300 Turntable: Technics SL-J3 with Audio-Technica TR485U Speakers: JBL HLS-610 Subwoofer: JBL 4648A-8 Sub amp: Parts Express 180 watt Center/surrounds: Teac 3-way bookshelfs Yes, it sucks, but better to come. KLIPSCH soon! My computer is better than my stereo! For JBL related subjects and more fun, click: http://www.audioheritage.org Quote Link to comment Share on other sites More sharing options...
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