Hello everyone!
First, I want to apologize if the translation is bad, being French I use a translation site to put everything in English, if things are mistranslated or incomprehensible, let me know 🙂
So I will explain my situation, I always wanted to have a subwoofer in my car, so I went deep into the search.
At first I wanted a closed subwoofer of 300/350W RMS, except that in the end, given the prices for such power in closed box, I preferred to go on bass-reflex or other because it is much cheaper.
Except that I realized that the dual subwoofer drivers were not so much more expensive than single sub driver. So I decided to start with that.
Then came the choice of an active or passive housing. I found some nice active sub (price/power level), but when I looked a little more closely, I saw that the integrated amps were not necessarily ideal (example: barely 2x50W RMS for a 2x300W RMS sub driver), so I have a first question: Why is it so different? Can we trust the active sub?
Sub in question: Edge Car Audio DB EDB12TA-E0 (2x 300W RMS)
Integrated amp in question: ED7300
Personally, I concluded that it was not, so I started looking at the passive sub.
That’s when I thought: since I plan to take dual subwoofers, it is better to put them on stereo, so I have a second question: Is it really worth it? I read that we perceive very badly the stereo with bass and most of the time, they were mixed in mono, except that I want to dream!
I have always been very sensitive to the pan (left/right variation) on instruments, and as far as to make as much have the best sound possible! (I really want to believe that the stereo is worth it, but if not, so be it ...)
Finally, to return to the sub, I found one that interests me strongly in view of its price, but especially that in the manual there is an instruction (screenshot support) to connect it in stereo (which I did not find in the manual of its lower version the B1 210):
Sub in question: GAS Mad B2 210
It is therefore a 600W RMS, or 2x300W RMS.
Looking at the 300W RMS dual channel amps in 4 ohm, I came across amps at 300 € minimum! In any case, too expensive for me.
Then I went to a second-hand amp and came across this one:
Amp: TN4 900D
Only 40€! With 4 channels 2 ohm and 2 channels bridged 4 ohm to 450W RMS. My main question being: can I make a stereo installation by connecting the 2 sub drivers with 1 pair of channels bridged 4 ohm 450W RMS each?
I read somewhere that it is not possible stereo in bridge because the 2 signals (stereo right side and stereo left side, I do not know how to describe this) add up to form a mono signal at the end. Talking with an AI (GPT chat) I may have learned that actually the 4 channels of this amp (and probably for all amps if it’s real) are in fact separate on the stereo right side and stereo left side.
Then I wondered if there are 2 right and 2 left channels, so why not make two pairs of the same side (right + right and left + left) instead of making two pairs with 1 different side (left + right x2)? And then make a stereo installation?
Does it make sense? I don’t know much about it, it may be lunar for connoisseurs. Thank you for enlightening me!
If something is misexplained/mistranslated, I apologize and will do everything to clarify it 🙂
PS: at the base I was going to take 2 used amps at about 300/350W RMS in 4 ohm rather than a multicanals amp but since I came across this really cheap amp I wonder what is best. And if it is possible, is 450W RMS per subwoofer driver not too much for 300 W RMS?
First, I want to apologize if the translation is bad, being French I use a translation site to put everything in English, if things are mistranslated or incomprehensible, let me know 🙂
So I will explain my situation, I always wanted to have a subwoofer in my car, so I went deep into the search.
At first I wanted a closed subwoofer of 300/350W RMS, except that in the end, given the prices for such power in closed box, I preferred to go on bass-reflex or other because it is much cheaper.
Except that I realized that the dual subwoofer drivers were not so much more expensive than single sub driver. So I decided to start with that.
Then came the choice of an active or passive housing. I found some nice active sub (price/power level), but when I looked a little more closely, I saw that the integrated amps were not necessarily ideal (example: barely 2x50W RMS for a 2x300W RMS sub driver), so I have a first question: Why is it so different? Can we trust the active sub?
Sub in question: Edge Car Audio DB EDB12TA-E0 (2x 300W RMS)
Integrated amp in question: ED7300
Personally, I concluded that it was not, so I started looking at the passive sub.
That’s when I thought: since I plan to take dual subwoofers, it is better to put them on stereo, so I have a second question: Is it really worth it? I read that we perceive very badly the stereo with bass and most of the time, they were mixed in mono, except that I want to dream!
I have always been very sensitive to the pan (left/right variation) on instruments, and as far as to make as much have the best sound possible! (I really want to believe that the stereo is worth it, but if not, so be it ...)
Finally, to return to the sub, I found one that interests me strongly in view of its price, but especially that in the manual there is an instruction (screenshot support) to connect it in stereo (which I did not find in the manual of its lower version the B1 210):
Sub in question: GAS Mad B2 210
It is therefore a 600W RMS, or 2x300W RMS.
Looking at the 300W RMS dual channel amps in 4 ohm, I came across amps at 300 € minimum! In any case, too expensive for me.
Then I went to a second-hand amp and came across this one:
Amp: TN4 900D
Only 40€! With 4 channels 2 ohm and 2 channels bridged 4 ohm to 450W RMS. My main question being: can I make a stereo installation by connecting the 2 sub drivers with 1 pair of channels bridged 4 ohm 450W RMS each?
I read somewhere that it is not possible stereo in bridge because the 2 signals (stereo right side and stereo left side, I do not know how to describe this) add up to form a mono signal at the end. Talking with an AI (GPT chat) I may have learned that actually the 4 channels of this amp (and probably for all amps if it’s real) are in fact separate on the stereo right side and stereo left side.
Then I wondered if there are 2 right and 2 left channels, so why not make two pairs of the same side (right + right and left + left) instead of making two pairs with 1 different side (left + right x2)? And then make a stereo installation?
Does it make sense? I don’t know much about it, it may be lunar for connoisseurs. Thank you for enlightening me!
If something is misexplained/mistranslated, I apologize and will do everything to clarify it 🙂
PS: at the base I was going to take 2 used amps at about 300/350W RMS in 4 ohm rather than a multicanals amp but since I came across this really cheap amp I wonder what is best. And if it is possible, is 450W RMS per subwoofer driver not too much for 300 W RMS?
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1. Bass in car audio should not be localiseable and phonograms in fact provide it in mono, so there is no particular reason to strive for stereo bass.
2. If you are OK with space, weight and cost of dual head sub - why not, you'll get more bass out of it)
3. Soundstream TN4.900D is a good versatile amp and it fits perfectly dual head bass box with drivers 4 Ohm each. I have checked the manual - you put it in 2ch mode, feed R+L into front RCA and get 2 power outputs: (FR+, FL-) for one driver and (RR+, RL-) for another.
4. It's OK to use 450W amp with 300W drivers. In fact you'll get less than 450W as power wiring is long and amp never gets 14.4V.
5. To save drivers in bass reflex it's vital to properly tune HPF! You should not ask the sub to play below it's tuned frequency!
2. If you are OK with space, weight and cost of dual head sub - why not, you'll get more bass out of it)
3. Soundstream TN4.900D is a good versatile amp and it fits perfectly dual head bass box with drivers 4 Ohm each. I have checked the manual - you put it in 2ch mode, feed R+L into front RCA and get 2 power outputs: (FR+, FL-) for one driver and (RR+, RL-) for another.
4. It's OK to use 450W amp with 300W drivers. In fact you'll get less than 450W as power wiring is long and amp never gets 14.4V.
5. To save drivers in bass reflex it's vital to properly tune HPF! You should not ask the sub to play below it's tuned frequency!
Your wiring options for it's two 4ohm coils are series (8 ohms) parallel (2 ohms) or two 4ohm coils to two separate amp channels as depicted in the "stereo/direct" connection.
If the input of the two separate amp channels are stereo, the coils "fight" each other with any stereo information.
There actually is quite a bit of stereo low frequency information in most recordings, so not a good idea to combine stereo LF in one driver.
The TN4 900D amp does not support 2ohm bridged (two 4ohm coils in parallel) operation, which would be equivalent to a 1ohm load on each channel.
Bridged output into 8ohms (two 4ohm coils in parallel) would be around double the 4ohm rating of 145 watt, 290 watts per driver, half the 600W "power RMS" rating of the GAS Mad B2 210.
You are right, but the GAS Mad B2 210 has two separate drivers, thus "stereo" connection won't be a problem and TN4 900D can power it fine in 2 bridged channels config.
The GAS Mad B2 210 has two separate voice coils, which if connected to a stereo source may fight each other if connected like Ozo suggested
when stereo information is presented, as it often is, as can be seen in this thread:
In the above example, half of the ~6dB difference in bass between channels would be converted to heat, and the bass that should have been heard from one side would be ~3dB less due to the other voice coil resisting the movement.
when stereo information is presented, as it often is, as can be seen in this thread:
Here is my take on Light My Fire. It's a very stereophonic mix. You can see that it's consistently about 5.5dB more side than mid, all the way across.
If two separate drivers are used for stereo bass the difference information is not a problem, both drivers are free to follow the electrical input.
This is what google offers me for the query GAS Mad B2 210 - box with two drivers)
In bridged 2ch mode TN4.900D will deliver same R+L signal to both drivers - "mono bass".
If (for some reason) owner wants a "stereo bass" it's still possible with this amp.
Put it in 4ch mode and use two Y-type RCA cables, right channel to front LR and left channel to rear LR - with same driver's wiring as for 2-ch.
Though I wouldn't do this for the reasons @weltersys described, especially in the car, especially with a single box sub.
Any stereo bass effects will be cancelled by small volume in the car and close drivers position.
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