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JBL 4638/4648A-8 update:


kenratboy

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As I and a few other people on this forum are responsible for a bunch of you getting the dual 15" JBL sub, I just want to see how you are doing with it.

Is everyone happy with it? Does anyone with they could kill me for making you waste your money on it? Does anyone have any, including minor, issues with the sub? Is anyone still awaiting delivery?

Just checking up, hope everyone who bought them on my, or someone elses advice is happy with them!

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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!

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I stuffed each of mine with 4 pounds of polyfil. Takes the boom of the very low bass. I also put on a set of 5 way binding posts so that I could run my good speaker cables with them. I am now trying to figure out where I want the crossover frequency set.

Jim Norvell

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JBL does know what they are doing and it is very well designed (the box). Unlike a small, powered subwoofer that has a butt-load of EQ's in it to make the box deficiencies go away, the JBL is ment to translate the input signal into EXACTLY what it should be. If the sub is in a small room, it can overpower the room.

My room is 320ish sq. ft. and the darn sub makes EVERYTHING vibrate. That includes a 400 lb. file cabinet, the wires inside the walls, and anything else the sound waves find. I hope my new house will be a little better build, this one is CRAP!

If the polyfil worked, GREAT! I hope you are enjoying it, there is enough bass to go around.

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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!

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Mine is coming tomorrow, and I am going to see how this old receiver powers it. I was wondering though, where are you mounting your parts-express plate amps for thoseof you who have bought em. I figured on the back or something, but I am not totally sure how big they are and haw far they are going to stick out if this old amp doesnt work out.

Thanks

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Klipsch RF-3 IIs

Klipsch RC-3

Klipsch RS-3s

Paradigm PW-2200

Sony STR-DE945

Sony DVD

JVC 32" TV

JBL 4638

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NO!!!

DO NOT mount the plate amp on the subwoofer itself. First, it would be a shame to cut a big hole (it would fit) in the box. Second, this sub will last forever, and if you or me some across a bigger, better amp, we don't want that tumor (plate amp) in the sub. Third, the sub is big and heavy, so it would be a ***** to have to move it around. Fourth, ss the sub is, it would fit nicely into a corner or flush against a wall standing up ot on its side. The amp would prohibit this placement.

I have PLACED the amp on top of the subwoofer with a hand towel under it to prevent slippage or scratching. I will eventually build it into a box and place it on my equiptment rack.

Enjoy, but I would strongly advice that you DO NOT mount the sub amp in the sub itself, it ruins the futrue of the sub.

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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!

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Still waiting for mine (ordered on 2/25/02-credit card charged). Already have my PartsExpress amp. Guess I can't complain, based on the price paid. Will post when I get it cranking.

CT

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You can tune a radio, but you can't tuna fish!

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Ok, the big truck showed up today and I had to help the delivery guy move a bunch of palletes to get to my JBLs, which we struggled into my house. Great!!!

Now, I've got the PartsExpress 250W sub amp. Do I just connect the black/red leads off the circuit board to the terminals on the back of the speaker cabinet? What kind of wire do I use? 12 gauge speaker wire? Something else?

Someone give some guidance, please.

CT

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=====================================

You can tune a radio, but you can't tuna fish!

=====================================

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jnorv is correct about the cable installation.

Mr. Tuna Fish: OK. to connect the amp to the sub you SHOULD get some "Soderless connectors" which are basically the male end to what is on the end of the red & black leads on the amp. If you cannot get these connectors, you COULD soder the speaker wire on, but this is too perminant. Go to a hardware store and ask/get some SODERLESS CONNECTORS. You will be able to crimp them onto the speaker wire and then plig them into the leads on the sub amp.

Good luck. Ask is you need more help.

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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!

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I had actually gone to my local ACE hardware and got two stretches of 16 AWG along with two male connectors. Just couldn't figure out how to get the wires on the posts. Thanks. Now I'm thumpin'!

How do you set your phase? By listening? What do you listen for? Thanks for the help guys.

BTW, has anyone considered building a grill for these beasts?

CT

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=====================================

You can tune a radio, but you can't tuna fish!

=====================================

This message has been edited by CharlieTuna on 03-12-2002 at 07:17 PM

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I also have a JBL 4638 coming. I already have in hand the parts express 250 watt amp. My question is the literature with the amp describes how to modify the EQ by changing 2 resistors out. What exactly does this mean, and has anyone done this?

Thanks

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The resistors control the bass boost. I have not messed with them. It looks like, if you knew what was going on with the boost and the subwoofer, you could use this as a EQ. I am not that good with audio and lack the equiptment. It's set in a position to benefit the 4638 right now, so I would leave it unless you had a handle on what it was you were doing.

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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!

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I'm thinking of taking Tom Brennan's suggeastion and just leave the parts express plate ampss siting in their inner shipping material which I may spray paint black to match. Good ventalation, cheap and sure to produce some "what the hell is that?" comments.

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Soundog's HT Systems

This message has been edited by soundog on 03-13-2002 at 08:33 AM

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Well I got my 4638 today. I didn't tell my wife exactly how big it was so she was kind of shocked.

My question is on the sticker in back with serial number it says the impedance is 8 ohms. In the literature I downloaded from JBL it says the impedance is 4 ohms. What does everyone elses stickers say? And which is correct?

Also I just assumed it came with a front grill, which I guess it doesn't since mine didn't have one. To make it more tasteful for my wifes decor, I am going to have to do something to cover the front. Any suggestions?

Thanks Benny

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