Second Amp For My Sub ?

[forceof1]

Hey everyone! I upgraded from a Rotel amp to a Marantz 250. Now I have an extra amp. I would like the Rotel to power the sub. Here's the eqpt layout....... M250, Rotel RB 980X, 120 wpc. .03% dist. Nikko Beta 50 Preamp, has 2 outputs, 2 processor in/out and tape. Sub is nothing special Sound Dynamics RTS 1000 powered @100 wpc or passive. Amp's have only RCA in and R,L out.

Right now The Rotel receives from the Nikko, then speaker wires to the sub. Is there a better way? Don't beat be up too badly, always in search of knowledge and a better system.
David

 

[swechsler]

There's not really anything you can do with your existing equipment. You can't drive a powered sub with an external amp without hacking it up (the sub, that is) and it's unlikely that you'd hear any improvement. Additionally, you'd need to add a low pass crossover, since none of your equipment appears to include one. At the moment there's no need for the Rotel amp at all, just connect the sub to the same outputs that the speakers are connected to.

You could connect the subwoofer to the preamp using the second set of pre outs on your preamp instead of through the speaker wires, which in theory would be better, but again it's unclear if you'd hear any actual improvement.

A better way to go about this to let us know what it is you think your system is lacking, or what do you think can be improved? Just making random changes is not the way to do it.

 

[fill35u]

You can't drive a powered sub with an external amp without hacking it up (the sub, that is)

Well, he could pull the driver, disconnect and cap off the wires from the sub's amp, run a pair of wires through the port to the driver, and replace the driver. Not really "hacking it up", but the wires would probably need to be secured to prevent noise from them vibrating.

Other than that, I agree that the whole exercise seems pointless.

 

[David_NC]

Build a sonotube subwoofer! That's what I'm doing, once the driver is in stock.

 

[forceof1]

Well, he could pull the driver, disconnect and cap off the wires from the sub's amp, run a pair of wires through the port to the driver, and replace the driver. Not really "hacking it up", but the wires would probably need to be secured to prevent noise from them vibrating noisily.

Other than that, I agree that the whole exercise seems pointless.

 

[forceof1]

Ok, makes sense. So I really have 2 or thre options. 1. Sell the amp and sub to get a better sub. 2. Use the existing sub cabinet and build it out with new electronics. 3. Sonotube sub of which I know nothing about as far as to whether or not thats a "good " thing to do. Thanks for your help. Recommendations on sub driver and crossover etc. I could make a passive sub and use the Rotel.........

 

[fill35u]

Like @swechsler said, what are you trying to accomplish? Bass eats up a lot of power and physical space, and exponentially so the lower and louder you want it.

A reasonable approach could be to first determine the maximum volume you want from your main speakers. Then determine what cutoff frequency and slope you want for the subwoofers. And then determine the absolute largest size cabinets you could tolerate, and how many. Armed with a volume, frequency, and cabinet size, you'll have an idea what it will take to get there.

At that point, budget and skill set determine what you'll actually end up with.

 

[the skipper]

Ok, makes sense. So I really have 2 or thre options. 1. Sell the amp and sub to get a better sub. 2. Use the existing sub cabinet and build it out with new electronics. 3. Sonotube sub of which I know nothing about as far as to whether or not thats a "good " thing to do. Thanks for your help. Recommendations on sub driver and crossover etc. I could make a passive sub and use the Rotel.........

IMNSHO, the best option would be # 1,

 

[swechsler]

IMNSHO, the best option would be # 1,

Agreed. If you think you need deeper bass, the best way to get it is to get a better subwoofer. Using a different amp as mentioned earlier is unlikely to provide much if any improvement, plus you'd have to purchase an external crossover.

But the question still remains: what's wrong with your current setup?

 

[gadget73]

Since your sub can apparently be passive or active, you shouldn't have to modify it. I don't really think you'd get much by running an external amp though. You'd also need to add a crossover in the mix.

 

[fill35u]

Since your sub can apparently be passive or active, you shouldn't have to modify it.

I don't know where the OP got the idea that his sub, from the factory, has the ability to be used passively. From what I can tell, it's like most other powered subs in that it *can't* be used passively without a little workaround.

Small low-powered subs like that are pretty useful as near field mid-bass modules