Once again it's.....DTS DigiTheatre!!!

[albertz]

Can anyone offer any advice on this problem:

My Digitheatre, when playing heavy bass moments ,makes a very distinct rattling sound from the two air portals at the rear of the sub unit. The speakers are all set to position 6, with the sub a notch down at 5. As I say, it is only on really 'bass heavy' portions of movie soundtracks, and is noticeable on both DTS and AC-3. An ideal moment to demo this is the opening titles to 'The Fifth Element' Superbit edition, but there are various other DVD's I could mention.
I wonder wether it is a case of the bass being reproduced too clearly on certain discs which results in the limitations of the sub being exposed. Or do any DTS DigiTheatre owners (and I know there are a lot of you out there) have any comments?

[Tony Keats]

This is a commonly aired complaint round these parts and I used to have the same system myself. I cured the problem temporarily by turning the sub down to 3/4 lights. As this low setting has a negative effect on overall performance, I cured the problem permanently by getting rid of the Digitheatre altogether!.

Now, obviously that doesn't help you a hell of a lot, but that's my story nonetheless....

Okay, here's what you do. Contact Videologic (support@videologic.com) and explain the fault. With any luck they'll offer to send you a replacement sub (on an "old for new" basis) for no charge. You might have to pay delivery charges or whatever, but it depends who replies to your e-mail really.

I swapped my Sub with them (for an entirely different reason) at no extra cost, so you might get lucky. In all seriousness though, have you considered upgrading? I recently bought a Marantz Amp (for little over £200) and the improvement is astonishing. Even bog-standard 2.0 tracks sound terrific with the DSP modes/DPL 2 and quasi 5.1 in action (which are all absent from the Videologic gear). Just a thought....

Good luck with the rattle scenario anyway!

[westy1507]

Hi,

Sounds to me like your sub's speaker cone is simply 'bottoming out' under the pressure. This occurs when the speaker coil is overloaded and the cone simply reaches its movement limit. This is most probably the cause of the rattling you're hearing. If its doing this then you may have to consider another system that satisfies your power hungry needs. After all, the Digitheatre isnt really that powerful, a decent amp and speaker package will trounce it any day.
An amp like the Marantz mentioned above paired with a speaker package such as the Mission m7a4 (m74 floorstanding fronts, m7c1 centre and superb m7ds bipole rears), will give you the performance you never knew existed at such a low price point.

Hope this helps matey

Westy

[DunkWho]

I think its due to the "rattling" of the 2 ports on the back of the sub. If you run the sub at the same volume levels with the back pannel removed you wont hear any problems (therefore not bottoming out etc) - my theory is that its just the volume of air behind the sub (in the box) being shifted in and out of those 2 smallish port holes during heavy bass sessions causing a "rattling" noise. You might also want to consider the placement of the sub ... if the ports are facing the wall and the unit is quite close to the wall then airflow might be restricted.

my 2ps worth

Dunkwho
(PS - i run my sub at 4 "clicks" down from default, centre up 3, front right up a couple cos its positioned indirect of my ear behind another sofa - i'm extremely chuffed with the result!)

[Ron Hill]

My Digitheatre DTS is set with the front left and right at 6, the centre at 7, the rear surrounds at 4 and the sub at 5. Everything is sweet and balanced with solid surround imaging and there is no distortion discernible. It's also loud enough above 7 on the master volume to turn my living room into a war zone at the start of T2UE. :) I have had problems with the sub in the past and had to get it replaced but the new one is the mutts nutts and hopefully quality control at Videologic is ensuring that all new ones are as good as the one I currently have.

[albertz]

Ron,
I'm now on my third sub unit, and they've all demonstrated this problem! Just my luck I guess?!

Dunk Who,
Is it possible to remove the rear cover from the sub unit? If so, some advice please:)


Thanks for the feedback chaps :D

[DunkWho]

Originally posted by albertz
Dunk Who,
Is it possible to remove the rear cover from the sub unit? If so, some advice please

The complete back face of the sub box is held in with 16 screws plus 2 screws through the bottom of the sub which hold the amp & decode stuff firmly in the box. I took mine appart to look for loose cables that could be causing the rattling and played the unit with the sub open - no rattling, therefore not a "bottoming out" problem with the drive unit. I DONT recommend taking it appart ... live mains and warantee out of outness. Knowing just alittle about subs I know that the diameter & depth of the port tubes provides a maximum flow rate of air into and out of the box - at high bass volumes i think the flow rate is getting critical and the plastic of the tubes starts to vibrate (hence the rattle).

this is all suposition on my behalf ... after the quick check for rattly comoponents i put my set back togther, played with the levels, and havent worried about it since!