Driving Bookshelf and Sub w/ late 70's refurbed Marantz

[MitchellT]

Hi all,

I have been thinking about buying a 12" PSB subwoofer to compliment a pair of older PSB Alpha a/v's I received while helping a family friend move.

The Alpha A/v's are already 6ohm impedence.. the subwoofer is 4ohm (nom and minimal)... I know I am getting into territory here that may be best driven by an amp that isn't older.. But the amp I would be using in the short term would be my fully refurbished 1977 Marantz 2330 (not B).. It has been gone through inside and out by a tech and all caps, resistors and transistors replaced, re-biased, the whole deal.

I would be using the passive 100hz crossover option on the sub to take the lower freqs away from my PSB Alpha A/V bookshelves and just having the sub do that work instead (referenced from here http://www.technofile.com/articles/psbsubsonic.html).

I don't ever plan to get crazy with this set up, but I plan to run this in my living room before I buy a newer dedicated A/V receiver (for TV) that I am saving up for... which may be for 6 months or so.

Would this be ok for my amp in the short term if I ran it at a reasonable volume level?

Thanks!

 

[airtime]

The 2330 is a pretty rugged animal. However can I add just this one bit of ranting advice.

As audiophiles - and I'm using that term in a general sense???? I never understood why anyone would run a speaker line THROUGH a plate amp and then out to a speaker. We spend A LOT of money on speaker wire, crossover components and speakers. Then we run the speaker line through $1.38 worth of cheap electronics on a PCB board assembled in China, aka the crossover board in the plate amp. I've seen the same person spending hundreds on speaker wire and capacitors do that??? Just run the speaker wire to the speaker and then tap off a line to the plate amp.

But it should be fine anyway you wire it.

 

[MitchellT]

Thanks for your reply, I just wanted to make sure this should be OK. I figured the 2330 was robust enough, but I'd rather be safe than sorry.

As for the hookup.. I am really new to subwoofers, and have never hooked one up before, so I was just thinking that might be the best method based on what I had read about its hook up options.. But what you say about routing it through the sub then to the speakers totally makes sense. I am definitely on a budget though so no expensive speaker cables for me! However, I was a little confused with your comment about running the sub from the speaker, you mean in series, just like daisy-chaining it from one of the speakers?

Alternatively, could I use the pre-out jacks on the back? I know the tech I saw put jumpers on the back of mine (preout to main in), but isn't there an internal hookup that didn't require those jacks in the first place, that would allow me to use the pre-out directly to the sub and then utilize sub's own amp?

I thought the jacks he installed were just an added safety precaution for longevity?

 

[airtime]

I really don't remember if the 2330 has an internal hookup for a pre out? Easy way to tell is just pull out the jumper and see if the stereo still plays.

I recently started using stereo subs. Simply wonderful !!! Better sound stage and there is a coupling effect you get with a sub under the speaker. So I hook up my speaker tapped directly off the speaker. This way if I switch amps, which I often do, I don't have to fart around with readjusting the sub levels.

 

[Denten]

Use the "pre out" on the 2330 and the "Line Level Input" on the sub. If it is a "Powered sub" then the subs ohms are irrelevant as it has it's own amp. It is getting signal from line level, not the 2330's amp section.

 

[Denten]

They way you hook up that sub is this: Pre out, to "low line level input".......Then run another cable from the sub's low "line level output" jacks to the 2330's "main in"
The reason for hooking it up this way is so when you adjust the crossover frequency on the back of the sub, it can now control the cut off frequency of your main speakers just like a AVR. If you run just one cable from the pre out to the subs line in, and leave out the return line to the main in, the sub will still work but you will have no control over the main speaker cut off point ( Like lesser subs).

http://www.audioadvisor.com/pdf/PSB-Sub Series_manual.pdf

 

[whoaru99]

They way you hook up that sub is this: Pre out, to "low line level input".......Then run another cable from the sub's low "line level output" jacks to the 2330's "main in"
The reason for hooking it up this way is so when you adjust the crossover frequency on the back of the sub, it can now control the cut off frequency of your main speakers just like a AVR. If you run just one cable from the pre out to the subs line in, and leave out the return line to the main in, the sub will still work but you will have no control over the main speaker cut off point ( Like lesser subs).

http://www.audioadvisor.com/pdf/PSB-Sub Series_manual.pdf

Mostly correct, except the line level high pass filter is fixed at 80Hz; it does not change with the adjustment on the sub. Only the low pass filter frequency changes with the subwoofer crossover adjustment.

 

[whoaru99]

Thanks for your reply, I just wanted to make sure this should be OK. I figured the 2330 was robust enough, but I'd rather be safe than sorry.

As for the hookup.. I am really new to subwoofers, and have never hooked one up before, so I was just thinking that might be the best method based on what I had read about its hook up options.. But what you say about routing it through the sub then to the speakers totally makes sense. I am definitely on a budget though so no expensive speaker cables for me! However, I was a little confused with your comment about running the sub from the speaker, you mean in series, just like daisy-chaining it from one of the speakers?

Alternatively, could I use the pre-out jacks on the back? I know the tech I saw put jumpers on the back of mine (preout to main in), but isn't there an internal hookup that didn't require those jacks in the first place, that would allow me to use the pre-out directly to the sub and then utilize sub's own amp?

I thought the jacks he installed were just an added safety precaution for longevity?

I suggest trying it either way. Don't get caught up in the "oh it might hurt the signal" thing. The sound of the system with the bookshelves running on the sub's high pass may be better than running them full range. There are a lot of factors, but it's not unusual for the sound to clean up a bit by not having smallish speakers trying to reproduce low sounds they're not good at reproducing. If you don't like it that way, that's cool, but at least you tried and experimented and found out what happens with your gear.

As to the jumpers, if you end up going that way and using just pre out cuts the signal, then you can use "Y" cables. This will still loop the pre out back to main in, but also provide connection points for the cables to the sub. Again though, I suggest trying through the sub. You may find you like it better that way, or not, but at least you know with your gear.

 

[Denten]

Mostly correct, except the line level high pass filter is fixed at 80Hz; it does not change with the adjustment on the sub. Only the low pass filter frequency changes with the subwoofer crossover adjustment.

I stand corrected, yes it is fixed at 80Hz, still a nice option to have.

 

[whoaru99]

I stand corrected, yes it is fixed at 80Hz, still a nice option to have.

I agree. Many subs have no high pass filter at all. This one has HPF on speaker level and on line level. Can be quite handy with smaller speakers, sometimes even with larger ones.

 

[MitchellT]

Thanks to all who responded to this and helped me out. I am picking up the sub later and week, and I'll be trying both methods to see what best suits my needs in my current set up conditions.

Although this is going to be an intermediate set up in my living room area right now, I ultimately, want to use this set up for an A/V for a home theater.. so I think these bookshelves will becomes rears and the sub will be, well.. a sub for the set up.

Thanks again to all who helped out. Let the fine tuning begin!