|
Silver Member Username: Mikechec9Chicago/atlanta Post Number: 163 Registered: May-05 | this problem exists w/my soundstream vgs 12"s. have an epx2 and a 9835HU. at times, when i turn my car on (not necessaarily the ignition), i get spikes coming through my subs. initially, it was a burping bass sound, like a bass flutter. but more recently (as i believe my subs are now blown) the sound has turned into a scraping type of sound. i heard that the 9835 x-over caused similar burps in the higher octaves, but not the subs. i deactivated the xover anyway, and the problem still persists. this does not always happen, but when it does the rca amp (vga 1600.2) light flutters w/the sound. just need to know some possible causes from which i can delineate a plausible solution. thanks |
|
Silver Member Username: Mikechec9Chicago/atlanta Post Number: 165 Registered: May-05 | bump\ |
|
Gold Member Username: Jonathan_fGA USA Post Number: 4110 Registered: May-04 | Turn on thump. It's caused by the initial signal to the amp from the RCAs wire, the audio circuitry stabilizes once the power is applied. A good way to stop it is with a delay circuit such as this one from Stinger http://www.sfxaudio.com/products/dispItem.asp?ProdId=63361 It delays amplifier turn on so that the initial surge of power isn't amplified to the speaker. Make sure to check all your ground points, head unit grounds, and so forth before buying it. You don't want to spend the money if you don't have to I'm sure. |
|
Silver Member Username: Mikechec9Chicago/atlanta Post Number: 167 Registered: May-05 | ok. so i am only familiar w/the turn on thump that occurs once. this lasts about a minute or so before it stops, or the amp stabilizes. could this still be considered turn on thump, or is it something more critical. that is, have you ever heard of "symptoms" as such. |
|
Gold Member Username: Jonathan_fGA USA Post Number: 4114 Registered: May-04 | Didn't know it lasted that long. No, I wouldn't consider that turn on thump. Sounds like the input to the amp from the RCAs, but more extreme than just simple turn on thump. Hard to say what it is, really, start small with grounds like I listed above. Try to get that processor grounded to a similar or the same point. You can also start eliminating variables, like taking out the EPX2 and connecting the RCAs directly to the amp, changing preout channels on the HU, and so forth until you find a problem. |
|
Silver Member Username: Mikechec9Chicago/atlanta Post Number: 175 Registered: May-05 | thanks. i just purchased the rux-c701 and pxa-h701. so i was going to take out the epx2 anyway and redo the entire system. this includes installing my brahmas, so i didn't want to damage those as well (forbid). i'm hoping its a ground problem like you suggested and not a bad amp since they don't make them any more. thanks. |