View Full Version : Retune 4645

11-10-2011, 01:24 PM
I got my self 3x4645 (the ones with 2245h) today.

I would love to get a bit more VLF so I am thinking of "retuning" the cabinets to aprox 20hz :o: Is 20hz tuning too low tuning for 2245h in a 4645?

Would it be OK to close one of the ports or will this create portsounds? Is it better to make the ports longer?

11-10-2011, 02:34 PM
My thought is you might be better off using a bump/High-pass filter.

I tried blocking one of three ports, just for grins, and did not notice
an appreciable change in VLF timbre (in my particular listening area),
nor did I notice excessive port noise. It's easy enough to try though.

Most of the "slam" is higher in frequency anyway, and you'd give up
a few dB in the 40-50Hz range as well as giving up some excursion
in the low 30's, while benefiting some (amplitude-wise) below 30Hz.

11-10-2011, 02:47 PM
Thanx! I Will try blocking one of the ports tomorrow :)

My "problem" is that I've gotten used to my previous TC Sound LMS Ultra woofers and they had a lot more output in the VLF than these orginal have... so that's what I'm trying to do something with. For music the 20-30hz is not important at all but for movies I really miss it.

For those who don't understand the VLF, try this song: http://www.youtube.com/watch?v=49Uo0V1DNG8 At aprox 12 seconds (and several times later) you get these VLF tones that are pretty cool if you have the speakers. On my 4645/B460 I can hardly notice/hear anything except the movement of the woofer, but with the previous mentioned TC Sound, my sofa was almost moving and it sounded pretty cool :)

Even with EQ (i've used both BX63a, Antimode and others) I can't get simmilar result as my previous woofers, all I get is lots of cone movement without any real SPL :dont-know:

11-10-2011, 03:27 PM
I have a feeling you and TiDome would get along just fine :)

I know what you mean though... when I had my dual SUB1500's setup,
you could feel and hear things that just didn't come through with other

Mr. Widget
11-10-2011, 07:07 PM
I have a feeling you and TiDome would get along just fine :)
I recently had the privilege of visiting the Sub loving Ti Dome-ain... I think I know what you mean. ;)

About the 2245... a very fine woofer, actually an exceptionally fine woofer, though I think what you are seeking is more of a specialty infrasonic capable device. The W1500H is more along the lines of what you seem to be requiring.

That said, there is also room loading and room mode/cancellation possibilities as well... what I mean is, it is possible that where you are sitting there is a slight or perhaps significant suck out of deep bass. Has either the sub or listening position changed between the successful sub and your current 4645 experience? If there has been no change, then you may want to look at a different woofer solution... if you moved your listening position or perhaps the sub location, that may be your problem or a contributing factor.


11-12-2011, 06:38 AM
The room is also a great factor regarding the VLF (as well as other frq). How large is the room? What in on the floor, the ceiling and walls? If the floor in of concrete it is much harder to feel the VLF than if it is made of wood. I have no problem with the VLF in my room with my 4343B's. I have a CD with one of the largest church organ, and in the cover it shall have tones down to 16Hz at certain tracks. I can't hear that tone, but the woofer moves allot. Got to be careful with the volume on this one.:D

01-21-2012, 04:33 PM
Today I got these :bouncy:

http://www.hifisentralen.no/forum/index.php?action=dlattach;topic=62341.0;attach=295 352;image

I've replaced two of the 2245 in my 4645 cabinets and I honestly didn't think it would be that much of a difference, but I was wrong! The 2242 have really much more output below 35 hz than the 2245 in the 4645 cabinett. With the 2245 I ended up with the orginal tuning, but I'm going to lower it again now with the 2242, probably take it to 25hz like in the 4645C cabinet.

Lee in Montreal
01-21-2012, 05:15 PM
The 2242 have really much more output below 35 hz than the 2245 in the 4645 cabinett.

And I suspect the 2245 has more output from 30Hz to 20Hz... :D

01-22-2012, 12:37 AM
And I suspect the 2245 has more output from 30Hz to 20Hz... :D

Maybe in a larger cabinet, but in the 4645 cabinett 2242 have much more output below 35 hz than 2245 have :)

It has also greater sensitivity all in all (I would gues 3-4db) , so I had to turn down gain on the amp powering the woofers.

01-22-2012, 03:07 AM
It has also greater sensitivity all in all (I would gues 3-4db)
Not in the <80Hz range!

01-22-2012, 07:02 AM
Not in the <80Hz range!

I run them from 80 and down and trust me, they have greater sensitivity! Nomather what paper might say it's 100% sure the 2242 play quite a bit louder than my 2245 did in the same 4645 cabinet. To match the level of my speakers I had to turn down quite a bit now on the subwoofers, nothing else in m setup have changed.

Lee in Montreal
01-22-2012, 07:05 AM
I suggest you take some RTA measurements. I suspect the 2242 has more output in bass' upper range, but less in the 20-30Hz range. If it is the sound you like, then great. You're now a happy camper.

01-22-2012, 02:53 PM
As you can see from the first post, lack of VLF (<35Hz) was my main problem with 2245 in 4645. When I yesterday replaced the 2245 with 2242 in the same 4645 cabinet, for the first time VLF was pretty good from the 4645!

I'll see what I can do about measuring but I'm pretty sure my ears don't lie that much and that in fact 2242 has greater effenciy from <35Hz than 2245 in the 4645 cabinet. When I hopefully next week will retune the cabinet to 25hz like in 4645C the difference will hopefully be even bigger. (My tests with 25hz tuning on 2245 in 4645 was not very sucsessful)

Ccalculations also indicates that 2245H really need quite a bit larger cabinet than 4645 to get proper <30hz output.