it's worth a shot to ask!!!!!!!!!!!!

Discussion in 'Speakers' started by RyanSoares, Dec 23, 2003.

  1. RyanSoares

    RyanSoares Stunt Coordinator

    Joined:
    Oct 27, 2003
    Messages:
    50
    Likes Received:
    0
    i have a 5 year old car sub that i don't use anymore.... the outputs are speaker terminials.... my receiver Sony695 only accepts the rca type sub connection.... what are my options if any...... i got bored just now and ran speaker wire from the sub.... and cut off the male jack on one of my old rca cables spliced the wire and connected the speaker wire to the rca male jack..... pluged it in and..... it didn't work...
     
  2. John Garcia

    John Garcia Executive Producer

    Joined:
    Jun 24, 1999
    Messages:
    11,571
    Likes Received:
    24
    Location:
    NorCal
    Real Name:
    John
    The RCA out is a preamp out, it carries NO POWER. You need an amp.
     
  3. Wayne A. Pflughaupt

    Joined:
    Aug 5, 1999
    Messages:
    6,100
    Likes Received:
    33
    Location:
    Katy, TX
    Real Name:
    Wayne
    And a home theater sub. Leave the car gear in the car.

    Regards,
    Wayne A. Pflughaupt
     
  4. John Garcia

    John Garcia Executive Producer

    Joined:
    Jun 24, 1999
    Messages:
    11,571
    Likes Received:
    24
    Location:
    NorCal
    Real Name:
    John
    Car audio drivers are typically 4 Ohm, while home audio gear and drivers tend to be 8 Ohms, so this sub may not be a good idea unless you have an amp capable of handling this speaker. Car subs are not designed to be used in large rooms as well (cabin and/or trunk gain), so you are better off with a home unit.
     
  5. Ryan Schnacke

    Ryan Schnacke Supporting Actor

    Joined:
    Feb 5, 2001
    Messages:
    876
    Likes Received:
    0
    Actually most of the DIY home theater subwoofer drivers are 4 ohms, or in the case of DVC, are operated in a 4 ohm configuration. For example, the Adire Shiva, Tempest, Maelstrom, Daytom DVC, Titanic Mk1,2 and 3.

    Most receivers can drive a 4 ohm load reliably. If you find one that can't then its gonna be pretty cheap.

    And I say what the heck - the guy already has a woofer in hand. All he needs is a spare amp to drive it off the receiver's sub out and a DIY box. If nothing else, its a cheap experiment with valuable lessons learned.

    Ryan, if you have some information about the woofer, especially the T/S parameters then that would help us to figure out what kind of box you'll want. You'll need to find or borrow some home audio amp (Have an old receiver?) to drive it so that you can evaluate the results of your sub/box combo. If it works okay then you could get a subwoofer plate amp for $100 from www.partsexpress.com as a permenant solution.

    These guys are a little tired of car audio guys coming in here and thinking that everything they learned about car audio will translate directly to home audio. Certainly that is not true. And most car audio subs won't do nearly as well in the home environment. But some of them are actually flexible enough to perform in the home. And some will perform better than their specs would have you believe.

    I bought one of the 12 inch Bazooka subs during the $10 Return Buy deal. Put it in a 1.3 cu ft sealed box that I had built for my Dayton DVC. Surprise, surprise - it sounded just as good as the DVC. Maybe even better (gasp!). Claimed Xmax was only 2/3 that of the DVC so lower max output levels. But still, the Bazooka was $10 while the DVC was $75 (normally $120).

    Anyway, my point is that you shouldn't give up before you try. As the case above proved to me, the specs do not tell all. If it doesn't work well then you can still consider selling the woofer on ebay and using that money to help buy a home theater woofer.
     
  6. RyanSoares

    RyanSoares Stunt Coordinator

    Joined:
    Oct 27, 2003
    Messages:
    50
    Likes Received:
    0
    thanks for all the replies and the the suggestions, my old receiver's sub connection was a speaker connection, so now that i have my new avr it uses the preamp,.... i'm not a car audio guy, just asking a question.
     
  7. John Garcia

    John Garcia Executive Producer

    Joined:
    Jun 24, 1999
    Messages:
    11,571
    Likes Received:
    24
    Location:
    NorCal
    Real Name:
    John
    Quote:
    Actually most of the DIY home theater subwoofer drivers are 4 ohms, or in the case of DVC, are operated in a 4 ohm configuration. For example, the Adire Shiva, Tempest, Maelstrom, Daytom DVC, Titanic Mk1,2 and 3.
    For a powered sub, the impedence doesn't matter, since it's amp will be tailored to the driver(s) and it's config, DVC or not.

    Quote:
    Most receivers can drive a 4 ohm load reliably. If you find one that can't then its gonna be pretty cheap.
    This is only partially correct. Most will handle it, but not all of them will be happy. There are any number of receivers, even in the $500+ range, that will not tolerate a 4 Ohm load for long periods. When driving a sub that will likely draw more current than a typical bookshelf speaker, the amp will be driven even harder.

    I am not saying it is a hopeless cause, but one that will require a little research. If he can't get the specs for the driver, you might try a generic box from www.partsexpress.com and a 100w or 150w plate amp.
     
  8. Ryan Schnacke

    Ryan Schnacke Supporting Actor

    Joined:
    Feb 5, 2001
    Messages:
    876
    Likes Received:
    0
    "There are any number of receivers, even in the $500+ range, that will not tolerate a 4 Ohm load for long periods. When driving a sub that will likely draw more current than a typical bookshelf speaker, the amp will be driven even harder."

    That's pretty hard to believe when Ron Stimpson and Tom Vodhanel of SVS reported very good performance when using an $80 KLH stereo receiver to power one of their 4 ohm subwoofers.

    Besides, there are enough home audio speakers nowdays rated at 4 ohms that virtually all receivers should be designed to handle 4 ohm loads. I think its much more likely that if a receiver driving a 4 ohm woofer does give up and let out its "magic smoke" its because it was driven into clipping.
     
  9. Robert_Gaither

    Robert_Gaither Screenwriter

    Joined:
    Mar 12, 2002
    Messages:
    1,370
    Likes Received:
    0
    Don't forget Ryan the SVS is a large ported sub and doesn't need as much power as a small sealed sub would (of course one should also factor in room size and listening level as well).

    I would recommend that if you do use a car driver then either do a large sealed box or something along the line of a EBS ported (in other words, a large ported box) if you're missing the T/S parameters. The problem with most car drivers are that their FS is too high, xmax too small, and reliance on cabin gain for bass extention.
     
  10. Wayne A. Pflughaupt

    Joined:
    Aug 5, 1999
    Messages:
    6,100
    Likes Received:
    33
    Location:
    Katy, TX
    Real Name:
    Wayne
    Quote:
    That's pretty hard to believe when Ron Stimpson and Tom Vodhanel of SVS reported very good performance when using an $80 KLH stereo receiver to power one of their 4 ohm subwoofers. You’re not quite comparing apples to apples here, Ryan.

    First, a stereo receiver is generally more tolerant of difficult loads than a multi-channel receiver (although a multi-channel receiver driving a single 4-ohm load may well do that just as easily as a stereo receiver).

    Second, not all “4-ohm” loads are created equal. In the example you noted with the SVS sub, the 4-ohm load is (I assume) direct voice-coil. This is a much easier load to drive than a complex 4-ohm load from full range speaker with passive crossover elements. For instance, I’ve seen heavy-duty pro amps that could drive a 2-ohm voice coil load all day shut down in an hour or so when given a pair of 4-ohm full-range cabinets.

    Regards,
    Wayne A. Pflughaupt
     
  11. Ryan Schnacke

    Ryan Schnacke Supporting Actor

    Joined:
    Feb 5, 2001
    Messages:
    876
    Likes Received:
    0
    "Don't forget Ryan the SVS is a large ported sub and doesn't need as much power as a small sealed sub would"

    Yes, this is going to be true regardless of the woofer that you use. And of course you can fry any amp if you beat on it hard enough. This much I assume is common knowledge.

    Wayne, remember that this thread is specifically about driving a single car audio woofer with a home audio amp. So I think I am comparing apples to apples. The inputs on the SVS CS subs connect directly to a single voice coil. The inputs on Ryan Soares' suggested DIY sub would connect directly to a single voice coil (or perhaps it is DVC). Apples to apples. And like you said, stereo or multi-channel amp probably doesn't matter - only one amp channel will be used so the power supply only has to support that one channel. You're absolutely right that a receiver that is capable of driving a "4 ohm" 2-way or 3-way speaker with a difficult impedence curve is going to be easily capable of what Ryan needs it to do. The fact that he's only trying to drive a single woofer means that he shouldn't need to spend a thousand dollars on amplification.

    I'm just trying to encourage the guy to give it a shot. So can we agree that most stereo or multi-channel receivers would work at least temporarily, provided that it is a "4 ohm" woofer? If he's got a spare amp and some woodworking tools then this is a cheap and fun project. If the woofer is up to the task then it could certainly be improved upon later by adding a proper plate amplifier. And even if the woofer doesn't work well I'd think that the lessons learned along the way would be of significant value.

    Ryan, the first step is to tell us anything you can about the woofer itself. T/S parameters are especially helpful. Otherwise maybe we can find them online if we knew the Brand and Model. Even the manufacturer's suggested enclosure sizes could help.
     
  12. John Garcia

    John Garcia Executive Producer

    Joined:
    Jun 24, 1999
    Messages:
    11,571
    Likes Received:
    24
    Location:
    NorCal
    Real Name:
    John
    Quote:
    So can we agree that most stereo or multi-channel receivers would work at least temporarily, provided that it is a "4 ohm" woofer?
    Yes [​IMG]

    The only reason I gave any input against the idea is because I tried it out too a long time ago, and your comment that it is a great learning experience is a VERY valid point, as I learned a LOT from building my own subs (car) way back when. I built a dual 10" (4 Ohm) isobaric monster, with a passive x-over of my design (thanks to Vance dickason and the Loudspeaker Design Cookbook), including the woodworking and finishing, fed by a bridged 300w amp for my car. It was a beast for certain, eyeball vibrating power to the mid 20s. When I brought it into the house one day because my car was getting worked on though, I found that even with adequate power (not as much as in the car), it just didn't produce the same kind of SPLs or clean bass even when corner loaded. Granted 2Ohms was probably FAR too low of an impedance for the amp I was using (single channel of an old stereo amp) and I am surprised that it did not fry.

    Is it worth it to try? Absolutely. Just do a little more footwork up front and you could end up with something quite good for very little $$.
     
  13. Wayne A. Pflughaupt

    Joined:
    Aug 5, 1999
    Messages:
    6,100
    Likes Received:
    33
    Location:
    Katy, TX
    Real Name:
    Wayne
    Quote:
    Wayne, remember that this thread is specifically about driving a single car audio woofer with a home audio amp. So I think I am comparing apples to apples. I realize that, Ryan. But when you mention a direct-voice coil load in one paragraph, and in the next paragraph say “there are enough home audio speakers nowdays rated at 4 ohms that virtually all receivers should be designed to handle 4 ohm loads“ (assuming by “home audio speakers” you mean full-range systems and not raw drivers) I don’t know how I could have reached any other conclusion.

    Regards,
    Wayne A. Pflughaupt
     
  14. Rogozhin

    Rogozhin Stunt Coordinator

    Joined:
    Dec 5, 2003
    Messages:
    142
    Likes Received:
    0
    I'll be trying out my Kicker 10" solobaric in a small sealed enclosure (built many years ago) and compare it to my shiva-both will be driven by my NAD 901 bridged to mono.

    Rogo
     
  15. Ryan Schnacke

    Ryan Schnacke Supporting Actor

    Joined:
    Feb 5, 2001
    Messages:
    876
    Likes Received:
    0
    Yeah, Wayne, I was rambling about in that post. I guess its not quite a fair comparison. But at least the advantage lies on the correct side - meaning that Ryan should be able to use a cheap receiver to directly drive a 4 ohm woofer.
     

Share This Page