loss of some power to subs

Slippy · 04-23-2006, 07:26 PM

Here's my set up:
Stock HU (RBK)
MTX Thunder 202 (powering sub)
JBL CS 50.4 powering (4) 5 1/4" (Focals up front, Infinity Reference in rear)
10" Toby bandpass sub behind seat

Here's my problem:
It seems as though the sub does not always have the same thump. This morning I had a Tool CD in and had to put the Bass on at about 25% and it was still thumping incredibly hard...This afternoon I could put the bass all the way up and it was about the same as the 25% earlier in the day. I checked all of the connections and couldn't find the problem. Any ideas what could cause this?

frumpy · 04-23-2006, 07:42 PM

Problem is your box. Get a good ported box, the difference will be huge. The quality will be better and it will sound more consistant. New headunit wouldnt hurt either.

Slippy · 04-23-2006, 08:00 PM

Definitley not the box. The box is outstanding. Why do you think that? What explaniation is there for the power loss? Sounds like I have the bass turned down to about 1/4, but it's not. The head unit does suck, but I am keeping it since it makes the system non-apparent.

adam728 · 04-23-2006, 08:01 PM

Were you listening to the same track? Did other conditions change, such as window's being up / down, heavier traffic, etc? I always notice my stuff sounds much louder at night, and it's just because there aren't other cars/trucks/semi's around me causing the noise floor level to be so high.

frumpy · 04-23-2006, 08:10 PM

bandpass boxes are terrible. There is no such thing as a good bandpass box. The idea of them allows the sound (volume) to be maximized but the sound is extrememly inconsistant and the quality suffers. A friend of min bought used subs in a bandpass box we hooked them up to 1000 watt amp sounded good but would hit wierd highs and lows. Put them into an old ported box i had (custom job, $350 box) the difference was rediculous. Just about as loud but very good quality.

Slippy · 04-23-2006, 08:12 PM

The top has been off all day. Yeah I tried the same track (several times). It could just be my head, but it seems like the thump is not as strong. The amp is under the back seat. Could it be overheating (today is upper 80's outside) and powering down?

Slippy · 04-23-2006, 08:16 PM

Quote:

Originally Posted by frumpy

bandpass boxes are terrible. There is no such thing as a good bandpass box. The idea of them allows the sound (volume) to be maximized but the sound is extrememly inconsistant and the quality suffers. A friend of min bought used subs in a bandpass box we hooked them up to 1000 watt amp sounded good but would hit wierd highs and lows. Put them into an old ported box i had (custom job, $350 box) the difference was rediculous. Just about as loud but very good quality.

The box I have sounds good. I really think it has to do with the HU or AMP

http://www.toby.com/SUBWOOFE/advbp.htm

adam728 · 04-23-2006, 09:07 PM

Quote:

Originally Posted by frumpy

bandpass boxes are terrible. There is no such thing as a good bandpass box. The idea of them allows the sound (volume) to be maximized but the sound is extrememly inconsistant and the quality suffers. A friend of min bought used subs in a bandpass box we hooked them up to 1000 watt amp sounded good but would hit wierd highs and lows. Put them into an old ported box i had (custom job, $350 box) the difference was rediculous. Just about as loud but very good quality.

Sounds like all your experience is with pre-made universal style bandpasses. Try something made specifically for the sub being used. A bandpass can give flat-as-a-card-table responce over a wide range of frequencies and sound very good. Most pre-made ones are designed for that "look at me" bass peak around 60 hz, with crap everywhere else.

You can't make a sweeping generalization because of one setup you heard.

frumpy · 04-23-2006, 09:29 PM

Quote:

Originally Posted by adam728

Sounds like all your experience is with pre-made universal style bandpasses. Try something made specifically for the sub being used. A bandpass can give flat-as-a-card-table responce over a wide range of frequencies and sound very good. Most pre-made ones are designed for that "look at me" bass peak around 60 hz, with crap everywhere else.

You can't make a sweeping generalization because of one setup you heard.

Actually I have heard quite a few. My friend designs boxes for MTX thump and several other companies. The boxes I have had have all been custom made and designed by him and made using CNC machines.

**Blake** · 04-23-2006, 10:29 PM

I've heard a couple 4th order bandpass boxes that sounded good.

Prefab=crap.

**Blake** · 04-23-2006, 10:35 PM

Good example of a quality 4th order bandpass.

frumpy · 04-23-2006, 11:07 PM

Thats pretty interesting havent seen anything like that, id like to hear it.

adam728 · 04-24-2006, 06:05 AM

Wicked one, I so want to build one of those. Just need some extra $$$ and a table saw. Someday, someday. Is that yours? How do you like it? Using it in-car or home? Nice subs, RE kicks ***.....

frumpy - just because the ones you heard were custom doesn't mean they were designed for a flat responce. Like I said before, most bandpasses are built to give that big bass in the middle range, maybe 45-80 hz, and fall off sharply before and after that. You can make them have a very flat responce, you just lose output. My buddy whipped one up for a JL 8-WO, that little thing sounded amazing. It hit great from 30 hz all the way up to his crossover point, which I believe was 80-90.

**Blake** · 04-24-2006, 08:58 AM

Quote:

Originally Posted by adam728

Wicked one, I so want to build one of those. Just need some extra $$$ and a table saw. Someday, someday. Is that yours? How do you like it? Using it in-car or home? Nice subs, RE kicks ***.....

frumpy - just because the ones you heard were custom doesn't mean they were designed for a flat responce. Like I said before, most bandpasses are built to give that big bass in the middle range, maybe 45-80 hz, and fall off sharply before and after that. You can make them have a very flat responce, you just lose output. My buddy whipped one up for a JL 8-WO, that little thing sounded amazing. It hit great from 30 hz all the way up to his crossover point, which I believe was 80-90.

No, it's not mine. I saw it on Caraudio.com a while back, and I've always wanted to copy the idea. They look like RE SX 10's.

adam728 · 04-24-2006, 12:02 PM

Quote:

Originally Posted by Blake

No, it's not mine. I saw it on Caraudio.com a while back, and I've always wanted to copy the idea. They look like RE SX 10's.

Full design plans are available from the company that came up with that box, www.decware.com . It's supposed to have an extremely flat response and get loud because of the horn. Sounds like a great setup for an open air Jeep TJ that can't rely on cabin gain. Unfortunatly I don't really have room, so I want to build one for the house.

04-23-2006, 07:42 PM	#2
frumpy Registered User Join Date: Dec 2005 Location: Pembroke ON, Ontario Posts: 1,978 Profile Gallery Classifieds My Jeeps	Problem is your box. Get a good ported box, the difference will be huge. The quality will be better and it will sound more consistant. New headunit wouldnt hurt either.

04-23-2006, 08:10 PM	#5
frumpy Registered User Join Date: Dec 2005 Location: Pembroke ON, Ontario Posts: 1,978 Profile Gallery Classifieds My Jeeps	bandpass boxes are terrible. There is no such thing as a good bandpass box. The idea of them allows the sound (volume) to be maximized but the sound is extrememly inconsistant and the quality suffers. A friend of min bought used subs in a bandpass box we hooked them up to 1000 watt amp sounded good but would hit wierd highs and lows. Put them into an old ported box i had (custom job, $350 box) the difference was rediculous. Just about as loud but very good quality.

04-23-2006, 11:07 PM	#12
frumpy Registered User Join Date: Dec 2005 Location: Pembroke ON, Ontario Posts: 1,978 Profile Gallery Classifieds My Jeeps	Thats pretty interesting havent seen anything like that, id like to hear it.