2235 and 2245 in sealed enclosures

[Niklas Nord]

Does anybody know anything about using the 2235 or 2245
in sealed enclosures?

I dont have any calculation application to use for this.

I´m planning to buy a TacT, and with this be able to EQ the
lower freq up.

Also, i tend to use corner placed subs.

**The thing i would like to gain here is space, the smaler box
the better, BUT it should not have a BIG impact on sound
quality..

Is sealed box the best if i would like to EQ the driver?

I have the JBL MPA 1100, it will be able to deliver some serius
amount of power also..

WITH room gain, i would be happy with -3db @ 18hz

[4313B]

"Does anybody know anything about using the 2235 or 2245
in sealed enclosures?"

Yes

"**The thing i would like to gain here is space, the smaler box
the better, BUT it should not have a BIG impact on sound
quality.."

Wrong forum dood. You need to visit another forum that expresses an interest in finesse. The order of the day here is BIG and LOUD with cracked plaster walls, broken picture windows, dead pets, constant ringing in the ears, live Zappa until you puke, etc. etc.

[Niklas Nord]

OK
thank you

[4313B]

I'd be happy to take this offline where we won't be castigated for talking about small boxes and medium to low efficiency systems.

[Mr. Widget]

Originally posted by Giskard
I'd be happy to take this offline where we won't be castigated for talking about small boxes and medium to low efficiency systems.

I find that statement by itself offensive!

[Guido]

Originally posted by Giskard
I'd be happy to take this offline where we won't be castigated for talking about small boxes and medium to low efficiency systems.

Didn't you once mention to own a pair of BIG and LOUD 4430????

[TimG]

http://www.danbbs.dk/~ko/ubdwnld.htm
The program is called Unibox and runs under MS Excel. You just need to enter the TS specs for the driver in question at the beginning of the spreadsheet and you can compare the response in sealed, ported, passive radiator, or bandpass enclosures.

[4313B]

Originally posted by Mr. Widget
I find that statement by itself offensive!

Yeah Baby!

Originally posted by Guido
Didn't you once mention to own a pair of BIG and LOUD 4430????

Me??? Mere toys compared to some of the stuff these guys are running!

[4313B]

Yeah, I've actually checked that spreadsheet out before but have never actually compared it verbatim to the results given by BB6P, WinISD, LispCAD, etc. so I can't comment on it's "accuracy". Maybe some other forum members who have the various packages can do a compare.

Maybe it would even be of some benefit for us all to pick one driver, synchronize the T/S specs and post our results given a specific volume to work with using our software of choice. I'd be happy to use the ancient "JBL" formulas if others want to employ their various software packages. I think RobH suggested doing this very exercise some time ago, just not with a 2235H or 2245H sealed. Qtc = CD? Bessel? Butterworth? T/S parameters from the 2235H or 2245H product design sheet?

[Earl K]

Hi Giskard

Maybe it would even be of some benefit for us all to pick one driver, synchronize the T/S specs and post our results given a specific volume to work with using our software of choice.

Yes, I'm up for that. I can tune with MacSpeakrZ. What box size?

Something to match the S9500 tuning ( like a Bessel Qtc ) ? How about using the 2245h ? - since Niklas already owns some ( I think ).

regards <> Earl K

[TimG]

I can help too, maybe this weekend. I have Unibox, LspCAD, and I purchased a used version of Soundeasy that I need to install.

[Niklas Nord]

Yes i own both some 2245 and 2235

[4313B]

Sounds good guys. Lets use the T/S parameters from the 2245H Product Design Brief and a Bessel alignment (Qtc = 1/sqrt(3))?

[Niklas Nord]

great!

[TimG]

Using Unibox, with 2245H, in sealed box with Qtc=.577, I computed three different cabinet volumes based on the amount of stuffing used. With no stuffing volume is 219.5L, with the walls covered volume is 199L, and with heavy stuffing volume is 142.7L.
Performance estimated without accounting for compression or room gain with 300watts input.
Freq SPL in dB
100 119
70 118
50 115.4
40 113
30 109.5
20 102.5
16 98.5
Driver may exceed xmax below 32hz with 300 watts assuming a cold voice coil.

JBL 2235 same alignments but with 150 watts input. Volume: no fill 101.5L, walls covered 92L, heavy fill 66L.
Freq SPL in dB
100 114.3
70 113
50 110.6
40 108.2
30 104.8
20 98.3
16 94.3
Driver may exceed xmax below 24.4hz with 150 watts input assuming a cold voice coil.