Help with fomo - JBL 4645C Subwoofer

[Rahan]

Or the amp and a serious problem from the beginning. Which I supposed to be the right answer. The thing plays damn loud with 300 w

 

[sahil fardeen]

@sahil fardeen - how you applied B6 filter, was such option embedded into xti 1002 options? I also think the same that such EQ like B6 can increase power demand. It is still very strange to kill the pro-amp on 4645C woofer (super efficient) in domestic environment. Or you have great freedom to play super loud

No it is not builtin to xti and cdi unlike Dsi series. I had to manually apply it using HiQ net dsp. Made a preset. Pretty sure nothing was wrong in my end

 

[sahil fardeen]

@sahil fardeen - how you applied B6 filter, was such option embedded into xti 1002 options? I also think the same that such EQ like B6 can increase power demand. It is still very strange to kill the pro-amp on 4645C woofer (super efficient) in domestic environment. Or you have great freedom to play super loud

Yes i do have the freedom to play it loud. Mine is a dedicated theatre room with tightly sealed toughened glasses so nothing really escapes out of the room. Not even my family complaints about it as they can barely hear anything. Personal house so my neighbors are like atleast 20m away from my space. So yeah, i can crank it as loud as i wish.
Few things to note are,
I am running the amp via a 3KVA servo stabiliser. The socket from my main supply its connected is to a 10A circuit. If incase, it was overloaded, it would have tripped my main circuit breaker which it did not.
And i have also run my previous subs(that too dual, martin logan subs rated to like 850W rms each) in the same circuit at max chat and no issues till date.

Even with my previous subs i did record peaks of 110-115db in bass region in movies

 

[sahil fardeen]

Or the amp and a serious problem from the beginning. Which I supposed to be the right answer. The thing plays damn loud with 300 w

Well i was running it bridge and it hit the red lights.
Since xti1002 is rated at 1000w bridge and i hit the red limiter occasionally doesnt it mean i was asking 1000w from it? not uncommon for 4645C it can take 800w 24/7 and something like 1600/3200w for many many hours. This thing bears abuse like no other woofer.

And i did hear port chuffing on oppenheimer intro. That time too it did hit red.
Anyways no excuse for it to choke itself to death. It should have refrained itself from doing that.

 

[g_t_r]

If you have such great / dedicated environment. You need to go to D-class series like mentioned earlier XLS which is super efficient. My problem is more input signal issue and lack of B6 EQ, than lack of power from XLS. XLS bridged with JBL 4645C should shake the house, that is still my assumption.

 

[sahil fardeen]

If you have such great / dedicated environment. You need to go to D-class series like mentioned earlier XLS which is super efficient. My problem is more input signal issue and lack of B6 EQ, than lack of power from XLS. XLS bridged with JBL 4645C should shake the house, that is still my assumption.

Well, at one sense you are right
But even if you see the crown’s brochure, they themselves recommend crown xti series over the xls for subwoofer duty(will attach a screenshot, its from the DJ application guide under xls2502 webpage)

Yep technically class D should be a better choice for sub duty

 

[Rahan]

This "recommendation" is marketing. Keep in mind they sell it. I tried the XLS, xlc and dci on my main. No audible difference but the hiss from the tweeter. Don't worry the XLS will do the job.

 

[sahil fardeen]

This "recommendation" is marketing. Keep in mind they sell it. I tried the XLS, xlc and dci on my main. No audible difference but the hiss from the tweeter. Don't worry the XLS will do the job.

i hope more than it will do the job, it will do it with good authority

 

[sahil fardeen]

This "recommendation" is marketing. Keep in mind they sell it. I tried the XLS, xlc and dci on my main. No audible difference but the hiss from the tweeter. Don't worry the XLS will do the job.

i knew the whole power amp thing(for my high sensitive speakers) was a joke. Literally the jbl representative laughed at me when i told him i will be powering the jbl 3153 with just the denon receiver when i was about to buy them. He told me it would never work out as expected. His logic was 450W amp for a 450W speaker. Lol. I knew these were super sensitive so would only be using max 10-15W (around 102db sensitivity when i measured it in room). I kept quiet and stuck to my decision of using them with the avr alone.

Well months later now i got a chance to test out my 3153 with this xti1002. Barely any difference. I even got hiss from tweeters with this crown which was non existent in denon’s internal amps.

Sad that many who are not much technical fall for these kind of marketing traps. I fell for a lot in my initial stage

 

[sahil fardeen]

If you have such great / dedicated environment. You need to go to D-class series like mentioned earlier XLS which is super efficient. My problem is more input signal issue and lack of B6 EQ, than lack of power from XLS. XLS bridged with JBL 4645C should shake the house, that is still my assumption.

why not you actually test it out bridged single 4645C and let me know??
Going with the xls makes minidsp a must have...that adds up to the cost a lot.. hey thats why i was so worried in the beginning to whether go for xti1002.

 

[sahil fardeen]

Alright, still confused what to go for next. I can also get another xti 1002 open box which is basically brand new for $385 here. Damn this is going to be hard

 

[Rahan]

As you seem to listen insanely loud, you'd better take big. But as you said yourself 1500w will only bring 1.5 more dB. I think you should be careful about hearing damage. Bro, you just blasted a PA amplifier en a sub which is meant to be in pro cinema. And you did it into you home .... If you like "chest feeling", you can add a buttkicker. It works just fine

 

[sahil fardeen]

As you seem to listen insanely loud, you'd better take big. But as you said yourself 1500w will only bring 1.5 more dB. I think you should be careful about hearing damage. Bro, you just blasted a PA amplifier en a sub which is meant to be in pro cinema. And you did it into you home .... If you like "chest feeling", you can add a buttkicker. It works just fine

Hehe yep i listen really loud
By blasted yeah i mean i hit around 110db in LFE. Rest of the frequency spectrum like the dialogue and all the mids and highs would just be max 85db in movies, its just the bass that’s loud. Which is what even my previous home subs were capable of doing. That too without any distortion.

Problem arises mostly in B6 boost i guess. Maybe i will use it without B6 and rely on room gain to get a natural boost below 35hz… that seems the only way if i would have to continue using the xti 1002. But yeah i would still get the 20hz HPF in xti apart from the dreaded lower limit of 30hz in xls. So in that sense it’s great

 

[smygolf]

+3dB = double the power needed.
Then the highpass shaves of a bit from it.

And do not take for granted that you ned B6.
I do not need any B6, ok i have 2 in a baffle wall but still.
See the thin line - straight down to 20 without any help.

If i want to push it and extend the range it is possible.
But i would not go above 100dB

 

[sahil fardeen]

+3dB = double the power needed.
Then the highpass shaves of a bit from it.

And do not take for granted that you ned B6.
I do not need any B6, ok i have 2 in a baffle wall but still.
See the thin line - straight down to 20 without any help.

If i want to push it and extend the range it is possible.
But i would not go above 100dB

yep planning to try without b6, have already ordered another xti1002

 

[sahil fardeen]

baffle wall means its 1 pie, and your measurements coincide exactly with the graph from 4645C spec sheet

 

[Rahan]

You also can play with the Q of you hight pass. Maybe +3db is not what you need. Each room is different. If you're happy with something lighter your amplifier will handle it with more ease.

 

[smygolf]

baffle wall means its 1 pie, and your measurements coincide exactly with the graph from 4645C spec sheet

I would say it is better, JBL:s graph start to fall at ~30hz - mine after 20hz
But as Rahan says, every room is different

 

[sahil fardeen]

You also can play with the Q of you hight pass. Maybe +3db is not what you need. Each room is different. If you're happy with something lighter your amplifier will handle it with more ease.

that was also the part of my plan. Will experiment out a lot. If i can get away without the b6 then its good for the amp. Will be testing out a lot, have a umik 1 lying around

 

[sahil fardeen]

I would say it is better, JBL:s graph start to fall at ~30hz - mine after 20hz
But as Rahan says, every room is different

with that graph from JBL they had a steep filter cut set at 25hz instead of 20hz. Yes, your response is definitely awesome. One guy in youtube even recorded extension upto 8hz flat corner loading and applying b6 with 2 4645C’s.