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prs head
11-03-2008, 01:04 PM
My current system in my wifes ears needs more bottom end. Currently my system is tri amplified using a 2225 for the low end in a 5 cubic foot box tuned at 40 hz powered by a DC300A, A 2445 on a short horn crossed over at 1200 hz powered by a D150A series 2, and finally a crossover point of 6 k to a bullet tweeter powered by a D75A. I picked the crossover points by listening and JBL's recommendations. The system is in my opinion very dynamic and the low end is tight and explosive when you pour the coals to it.
The question is this I can add a sub of course. My thinking would be to add a single 18 in mono which would add another crossover point and one more amplifier. I have two more DC300A so thats not a problem. Im thinking to make it worth while Im looking at least an 8 cubic foot box to gain any low end extension. What other options are there that would be manageable? Im in between a rock and a wall as size does matter as I dont want to have the room taken over by boxes. Has anyone tried the isobaric box? I have had no experience with them all though I see they are small but power hungry. What about adding a couple of 2235's versus a single 18? It seems that the 2235 might be a more manageable box in the living room. I appreciate any suggestions you folks may have Im a rookie at this stuff and really need some help.Thanks in advance

stephane RAME
11-03-2008, 02:30 PM
My old amplifier CROWN

:D

robertbartsch
11-05-2008, 12:02 AM
Your current bass drivers in your mains are designed to go very low. The issue, I suppose, is that the program material in modern recordings such as DVDs, 7.1 and 5.1 tracks is directed to the "sub" channel.

After using several commerically store-bought home subs which are very dissappointing, I went with a JBL 18" 2242 in a 10 sq. foot cab which is powered by a Dayton 500 watt SS amp (8 ohms) that is designed specifically for subs.

This sub's performance in my HT is truly superb!

That said, the furniture grade box is freq'N huge! I suppose, since the Dayton amp has equalization, I could have obtained satifactory results with a much smaller cab. For that matter, you could also get very good results with a modern 15 inch JBL Professional driver with a separate dedicated sub amp.

I bought my sub driver used for around $300 and the amp was about the same dough.

Zilch
11-05-2008, 01:24 AM
Your current bass drivers in your mains are designed to go very low. Not....

Allanvh5150
11-05-2008, 01:41 AM
Hi,

Your 2225's wont go particularly low, they were never made for it. If you require more bottom end and don't want to take up a lot of room you could swap the 2225's for 2235's and retune the box for somewhere around 28-30Hz. Or you could recone the 2225 to 2235. :)

prs head
11-05-2008, 09:26 AM
Im wondering if the 2235 wouldnt be as dynamic sounding as the 2225. I may get yelled at for that statement but is the transient response of the 2235 as good ot the same as the 2225? Not knowing much about that driver it would seem (and Im probably incorrect in my thinking here) That the extnesion in the LF has to do with a heavier and therfore potential slower moving cone. Am I wrong in that thinking or does the magnetic assembly in that driver have the energy so that when a transient occours the cone will have quick response as a lighter cone would with the same size magnetic structure.
I can go the 18 inch route and that maybe the best answer. Im wondering if the boxes I have at 5 cubic feet would be big enough for me to get the LF extension I would like if I went to the 2235 and retuned. The system as it stands now sure isnt bad. It just could use a little something in the low end. I appreciate everyones patience in answering my questions and really appreciate the input

scott fitlin
11-05-2008, 09:37 AM
The 2235 is NOT as efficient as the 2225.

2235 is NO slouch at transient response, but will be audibly lower in acoustic output, and IF you like the 2225, which judging by your question, about "DYNAMIC" sound, you do, my recomendation is THE JBL 18 inch SUBWOOFER!

boputnam
11-05-2008, 09:40 AM
I can go the 18 inch route and that maybe the best answer. :yes:


I'm wondering if the boxes I have at 5 cubic feet would be big enough for me to get the LF extension I would like if I went to the 2235 and retuned. Run some models, dood.

PartsExpress carries the BassBox Pro (http://www.parts-express.com/webpage.cfm?FILTER=bassbox+pro&FTR=bassbox+pro&search_type=main&WebPage_ID=3) series of modelling software (boxes and crossovers). Just don't lend it to Widget - you'll never get it back. :D

As well, you can download WinISD (http://www.linearteam.dk/), a nifty piece of freeware that incorporates Thiele-Small paramaters for most popular transducers. These folks work hard at keeping their db up-to-date, so don't be shy of donating to the cause...

(as well, the Thiele-Small Loudspeaker Database (http://www.thielesmall.com/) is a nifty Link to make a favorite.

Have some fun, and good luck. Come back with questions - we've all done a bit of it...

JBL 4645
11-05-2008, 09:50 AM
What of the JBL 2241 that would be killer 18” for the deep lows it works great in the cinema. :applaud:

prs head
11-05-2008, 04:21 PM
I just downloaded winisd and since I have a resale account with parts express I will look into bass baox pro. Im in good shape with test equipment so I can do some experiments with tunings and such once I get something built. I have a buddy in Nashville who was going to trade me another pair of 2225 woofers but after my simulations I may just get that 18 inch jbl frame he has. I did talk to one of my broadcast suppliers who is a JBL dealer and will sell me stuff cheap ( if you by a $160,000 FM broadcast transmitter dealers are nice to you for awhile) and she says JBL has only 3 2235 woofers in stock and that is the end of them.
.Does anyone have any reconers that they have had good luck with and that they recommend? This 18 needs a kit in it and I would hate to have somebody throw generic parts in it
Thanks for the suggestions and turning me on to winisd. I think I will watch the Cream reunion on dvd and fiddle with winisd.

scott fitlin
11-05-2008, 04:29 PM
Well, forum member Edgewound is an authorized JBL repair, everyone here that has had him do some work says HE's TOPS!

You would have to ship to him in California, and I dont know of anyone in N Carolina.

Which model jbl 18 DOES YOUR BUDDY HAVE?

prs head
11-09-2008, 03:17 PM
A friend of mine will give me a E 155 frame to use as a sub. It needs to be reconed but I wonder if the kit is still around would this woofer be worth while as a sub for home? Any suggestions?
Thanks

pos
11-09-2008, 03:19 PM
you can install a C8R2245 kit on that frame, and get an exact 2245H.
I think the price is around 250$

This is a killer subwoofer for home use! You will get twice the output of a 2235H.
Some ideas for a box:
http://www.audioheritage.org/vbulletin/showthread.php?t=38

jbl
11-12-2008, 12:08 PM
Im wondering if the 2235 wouldnt be as dynamic sounding as the 2225. I may get yelled at for that statement but is the transient response of the 2235 as good ot the same as the 2225? Not knowing much about that driver it would seem (and Im probably incorrect in my thinking here) That the extnesion in the LF has to do with a heavier and therfore potential slower moving cone. Am I wrong in that thinking or does the magnetic assembly in that driver have the energy so that when a transient occours the cone will have quick response as a lighter cone would with the same size magnetic structure.
I can go the 18 inch route and that maybe the best answer. Im wondering if the boxes I have at 5 cubic feet would be big enough for me to get the LF extension I would like if I went to the 2235 and retuned. The system as it stands now sure isnt bad. It just could use a little something in the low end. I appreciate everyones patience in answering my questions and really appreciate the input
I changed my 2225H for the 2235H in the 4507 5 ft3 cabinets. Didn't lose the great slam the 2225 has, but gained a great bottom end. The true test will be when my brother stops over for a listen.