Help with fomo - JBL 4645C Subwoofer

[73hadd]

I passed on a chance to buy a couple of these:

https://jblpro.com/en-US/site_elements/jbl-professional-spec_sheets_pdf-4645c-spec-sheet

I was thinking:

-Quality subwoofers are a "solved problem" (new stuff is probably better)
-They are huge
-I don't want to buy separate amps/xover/eq etc.

I mean, they were cheap, like $150 each.

The spec sheet shows them looking pretty flat. Tell me what kind of mistake, or not that much of a mistake I made?

Maybe there is a spec in newer gear about extension or spl that that makes the older stuff less desirable. Otherwise wouldn't it be more expensive and sought after?

I should add that it is not a concern really to spend as little as possible. Let's compare this to what you can get for $1000 new these days, to help me understand the performance difference, if any.

Thanks!

 

[Wombat]

They were not for you. Buy and flip with a good profit?

 

[Zvu]

You'll never know now what would you get with new stuff compared to old.

If those woofers are in good shape, it would be a steal to get them for 150$. When i'm in a similar dillema, i always buy. Then i try it at my place. If i like it, i keep it. If not, i sell it but since they were cheap - i can sell it quite fast.

Jbl 2242H are pretty expensive transducers. Minidsp and some D class power amp would solve the problem for you. There are lots of icepower amps on ebay. Investing in that you would still be around 800-900€. Even if you didn't like it, selling just pair of transducers would pay for dsp and amp. That's how this hobby becomes sustainable (not just bottomless pit for cash) and you get to play with lots of gear and meet people with similar interests.

 

[Neddy]

I faced a similar choice, and Bought. With a new crown amp, it was still under $500 at the time, and this one had only been used rarely, so nearly new.
(The crowns have built in xovers for the 4645C.)

I'd be a bit concerned about how used ones have been 'used', though.
But as mentioned, this is a JBL Pro speaker, so will handle abuse others might not, and probably last longer.

Mine came out of a ad creator's corporate studio theater, which they spent huge bucks on, but had rarely used as the ad content creation game moved away from huge custom systems like that (but a JBL buyers wet dream when they CL'd it all!).

The seller - took them nearly a year to sell! - told me that the value was nil b/c no one wanted to haul around that big a speaker anymore.
The rest of their JBL/Harman gear sold in weeks. And other ads on CL I've seen for them bears that out - resale value is extremely low...so can be a good deal if that's what you want. OTOH, resale value on the Crown amp is decent, so as a combo, not all that bad?

I have the room, and built a grille frame for it, and then had some of the last 'authentic' JBL blue fabric attached, so it looks a bit like a mini-4350 now

As for 'compared to what', I can't say, but it does generate terrific SLAM impact, and does 20hz (w/EQ) very well. But no lower than that, which is fine for me.
I guess I'd claim that the size thing is a matter of cubic inches and would be really curious to compare for SLAM effect with more modern (and home theater type) subs...I just have this feeling the thing is capable of more dB.

If I had the $$, and was to do over again, I'd probably look real hard at some of the motional feedback subs available (for a price) now, mostly b/c they are smaller. Not quite sure you could 'beat it' for under $1k, however.

Also, my mains also do 20hz (2216s), so sometimes hard to tell who's doing what down there, but even so, the sub still stands out in HT use as the "great impact creator'!! Blowing out candles is a Snap.

It IS a beast though, so transport and moving is a very reasonable concern. No regrets for me, for sure.

The bigger question for me has been: would dropping a 2269 in there be a noticeable improvement?

 

[pwnz]

They actually aren't that great as HT subwoofers IMHO. Just recently I bought (and sold again with a huge profit) a pair of JBL 4642As with two 2241H drivers each. Originally, I wanted to keep them but was disappointed to be honest.

The transducers don't really like operating much below 40 Hz and require enormous boxes, low port tunings and heavy EQ to produce any meaningful sub-bass. This way, though, they exceed Xmax with just a few hundred watts which feels like a waste. They are much better off in a smaller enclosure where they can shell out insane bass SPL above 40 Hz. That's where they thrive IMHO.

For HT purposes I very much prefer more modern, high mass cone, low fs, long excursion drivers which can produce the same amount of bass in much smaller enclosures and go a lot lower without EQ.

 

[Zvu]

Well, you are comparing 2241 to 2242.

40mm vs 50mm Xmech
7mm vs 9mm Xmax
0.4 vs 0.28 Qts
And so on....

Not saying that you would be satisfied with it if it was 2242h instead 2241H in conditions you tested it.

None of those are HT subs of course.

 

[g_t_r]

What Crown Amp (from currently available as "new") would be best option to drive fully JBL 4645C (or B)? Any recommendation?

 

[Neddy]

I'm running it with the Crown XLS 1502, bridged. It has the 4645C in it's menu, so is easy to set up.
Though I got it (for a song) before putting the 2216ND-1s in my mains, I have no regrets (they both 'do' 20hz, or nearly so).
It seems to add 'SLAM' to certain movie and movie tracks that the 2216 by itself can't quite manage. A great floor shaker.

 

[g_t_r]

@Neddy, do you think stronger Crown XLS 2502 will bring any benefit over Crown XLS 1502 ? I'm trying to decide between those two. Do you hear any "underpower" conditions to fully drive 4645 sub?

 

[Neddy]

I haven't seen the 1502 hit any limits, though (for now) I'm running it at about 75-80%, but that's with the Venu 360 and OktoDac upstream of it, both of which have (the ability) to change gain and EQ (Venu, in real time).

I also have active clipping protection enabled on the Venu, and I do occasionally see that being tickled on loud movies, or orchestral pieces, but that's kind of by 'design'.

I got my 1502 long enough ago that the price was I think around $250, with an additional maybe $75-100 for the 2502, and I didn't see the need for it then (so the total subwoofer + amp cost was well under $500, and that was a basically 'never been used' 4645C!)

There may have been other considerations, like power draw; I'm runnning pretty close to the 15A breaker on occasion, though I have never tripped it.

I couldn't justify it then, but if an add'l $100 or so isn't a burden and you aren't concerned about current load on that circuit, I don't see reason Not to go with More Power...I've certainly never upgraded power amps because they were TOO powerful.

The sub can handle an obscene amount of power - its rated fora max continuous of 1600w 'power handling', so 2500w might assure you that the power band you are operating at is as clean as that amp can manage.
There is a JBL tech note comparing the 2242 to the 2269, which seems to show much 2269 has lower distortion, slightly better efficiency, and reaches above 1khz better - but both reach ~120db on 80watts, and (different measurements) show 2000 watt power handling.
(BTW, I still would love to try dropping a 2269 in to that box to see what it's able to do, but they've always been expensive, and now are even more so.)

Also, I'm running my mains with the 4367 woofer (2216ND1) which have a very similar freqency response, down to 22hz or so; I have lots of deep bass drive ability.
The ND1 seems (to me) to be cleaner, and sharper ('more clinical'?) in their bass response, but the power handling of the 4645C I think just overwhelms them at a certain SPL level?
I really like the combination....if one won' t 'kick it' the other one will.

BTW, I fabricated a grille frame for mine, and had it covered with JBL pro grille cloth (now no longer available AFAIK.)

 

[Audio Science Pal]

I have a pair of the JBL 4645C in my garage. Good subwoofers.

 

[g_t_r]

Thank you for extended info/post @Neddy! Still 1 question: is 4645C bass 'clean' ? (any audible resonances?? etc.) If yes I will probably make a move. I have 3677 fronts as main speakers (no deep bass, but great mid-bass kick and speed from 15' driver) so subwoofer will be great extension. Let's shake the house!

 

[Neddy]

You're welcome, glad to share my obsession.
As for 'cleanliness' I can't really say anything other than the 2216ND-1s are super clean in deep bass, the 4645C less so, but is far more 'impactful' in movies - though its really really difficult to tease out the differences. The 4645C does (can) excite building structural resonances at full chat - very very occasionally a movie might do that, but it's rare enough I dont try to 'fix' it, just dial it back a skotch.
The JBL tech notes clearly show the 2269 is significantly cleaner in distortion than the 2242, but - would that even be audible in the sub 100hz reign?
And finding a non-abused 2269 might be a challenge (as a car drives by with woofers so loud it's shaking the ground around my house! as if to make my point.)

 

[pauldavidthomas]

It tried the 1502 with the 4645C and found it didn't quite work or feel right. I was not doing any additional processing to the sound. However, when I tried the same sub on a Crown DSi 2000 bridged, it has a setting for this sub. Totally different. Don't know what it was doing, but totally different. Really shakes the room now when watching movies.

 

[g_t_r]

Very valuable comment, maybe you applied some dedicated EQ like +3-6dB boost. Or... simply better/higher and stronger amp model?

 

[Audio Science Pal]

maybe you applied some dedicated EQ like +3-6dB boost.

Yes, the 4645C is designed for what is called a B-6 alignment, +6db @ 25 Hz Q-2, and steep cut filter @ 20 Hz.

 

[pauldavidthomas]

Yes, the 4645C is designed for what is called a B-6 alignment, +6db @ 25 Hz Q-2, and steep cut filter @ 20 Hz.

I'm running via a Trinnov processor and give it +6 to 7db boost.

 

[Audio Science Pal]

I'm running via a Trinnov processor and give it +6 to 7db boost.

And the high pass filter @20 Hz, correct? Just asking. Otherwise, the sub-sonics will flop the cone past its X-max. Ouch!

 

[pauldavidthomas]

The Crown DSi handles that. I do also have a filter set in the Trinnov, you know, belt and braces and all ! Don't want any flapping !

 

[Rahan]

I have the same bass set up. Jbl 4645c with xls 1502 It rocks my world. Bass are clean, and impacfull. Hard to beat pricewise. But indeed, it's huge. in a domestic environment the spl capacity is basically limitless. It's sooo fun to me. I use it as a home theatre sub as well as a HiFi one. It does booth really good. It can play insanely loud or sweet and detailed . Zero complain about it. It match my jbl 708 perfectly.