I have some old 3-piece boxes that have banana clip style speaker connections on main unit for speaker connection.Some of these boxes sound quite good and others don't.I'm thinking of trying better speakers on these boxes.I'm not silly enough to think nice specialty monitors could be driven by my blasters.However on my frequent trips to the thriftstore,I have noticed speaker sets that have somehow gotten separated from shelf systems sold by some of the name brand manufacturers like Aiwa,Sony,etc..Occasionally these are available at really cheap prices.One set that caught my eye in particular were marked Aiwa SX-N220 3-way Bass Reflex speaker system 4 ohms.They had wood cabinets with particle board backings and were quite heavy for their size.Each one has speaker wires with bare wire leads.The units I have that would accept these leads are a Magnavox AZ8705/15 40 watt (I believe its speakers have single full range drivers though it's fairly loud),the Panasonic RX-DT680 57watt(bi-wired and amped with speakers labeled "High 8 ohm,low 2.7 ohm),and a JVC PC-200 at 53 watts input which has 6 ohm labeled speakers.The JVC in particular would be interesting to try different speakers with as it is rather bass shy but seems to have a lot of power and volume.How do I know what shelf system speaker would be a good and/or safe match for my 3 piece boomboxes?Would it be a problem for my boxes to drive the Aiwas I saw?
agree that those jvc center sections have LOTS of very clean power --and you probably know all this -- but dont go way under the ohm rating for the amp --
ie -- look at my jvc/panny avitar which i was told by some caring members to ABORT immediately -
due to the ohm mismatch
sure did sound good though !
Hey Jovie!
I have done this quite a bit. Here's where the real fun begins, try different replacement speakers in the original cases! In most cases the speakers are the bastard child with boxes. My little JVC PC 30 has way more power than it's speakers can handle so I actually ran my Infinity SM 60's on them and WHOA! This is actually pretty fun because you can really see what your boxes are made of. Component boxes especially. If your system is rated to 6 ohms you will probably be safe to 4 ohms. The problems start as the volume rises. A 4 ohm speaker will dip to about 3.5-3.4 ohms under high load. Under normal volumes no problem. Your PC-200 should not have any issues with a 4 ohm speaker as long as you aren't trying to blow your walls out. (Every decent amp is built to run a little higher and lower than rated impendance.)
The Panasonic however has a little something different going on in that the frequencies are split between the low and high impendance sections so it wouldn't be worth it unless you disassembled the experiment speaker and set it up to run bi-amped. Even then you have to have a good low impendance mid-tweet to achieve that goal and a well balanced mid-woofer otherwise I would not bother. I've got a DT-680 and it just seemed quirky when I goofed around with it.
BTW...Ya got and extra DT-680 control board? Mine has gone nuts.
Hey Jovie when you mod your RX-DT680 let me know what speakers you use and how they sound. I'm a bit sad with my original RX-DT680 both tape players are not working, I've tried using contact cleaner but to no avail. I may have to take it to a technician to have a look at it which I know will cost some bucks!
quote:
Originally posted by ford93:
Hey Jovie when you mod your RX-DT680 let me know what speakers you use and how they sound. I'm a bit sad with my original RX-DT680 both tape players are not working, I've tried using contact cleaner but to no avail. I may have to take it to a technician to have a look at it which I know will cost some bucks!
There is a way to clean the contacts. Do a search and you will see the link. It does work. But don't be a dolt like me.
The screw well have holes on the side of the wells at 12,4,8 o'clock to give you an idea of how they are spaced. Well, if you put a screw in the well and forget you did, and set antother on top, then try to drive it, it will slip off the side and sink through the side hole. Now you will not only have the one screw stuck but the one beneath it. The stuck screw will be at an angle. I managed to drill it out, but damaged the control board in the process. I managed to fix the control board but it has not been happy recently so I want to replace it. Got an extra?
oldskool69 are refering to the board which has these little red button that controls the tape players?
I'm sorry oldskool I don't have an extra, if I did it would have been in the mail to you by now sorry.
quote:
Originally posted by ford93:
oldskool69 are refering to the board which has these little red button that controls the tape players?
I'm sorry oldskool I don't have an extra, if I did it would have been in the mail to you by now sorry.
I appreciate that ford, but the board I need has the main controls on it, tuner,cd,etc.
redbenjoe-The information backplate on my boomboxes doesn't list an ohm handling rating for the actual amps.How am I to tell?On the speaker of the JVC PC-200,it says 6 ohm (10w nominal-20w max.)As I said,it sucks 53w from the wall socket.Can you tell anything from all of that?
oldskool69-Good info,thanks!I suppose I'll leave the Pana 680 alone.All that bi-wiring is a bit confusing.It's interesting that you have had success driving a name brand speaker with your box.That's something I didn't think would work very well.My intention is more to take advantage of the very inexpensive and less demanding (for power) shelf system speakers.This should give my boomboxes a leg up hopefully enabling them to put out sound similar to some of the amazing shelf systems.Besides the PC-200,I'm thinking that the Magnavox is capable of a lot more as it seems pretty loud.I want to see if they just skimped on the speakers.
ford93-I'm sorry to hear about your 680.Actually I engaged a button on deck 1 of my unit that I cannot get unstuck.I'm not familiar if you are a tape guy or not.Of course if your O.K. with digital,you can always play Cds.Most of my fun though with the 680 is from using the CD Line-out as a Line-In for my MP3 player.If your not familiar with this technique you must put a data CD in the disc drive and press play to hear your player through the line-out jacks.For some reason the CD laser will interpret the burned area on a CD-R as minutes of music.Since the area the laser tracks actually has no music on it,you will hear the tunes you are feeding into the line-out jacks!If you really want to play your tapes,perhaps you could feed your home tape deck into your 680 in a similar fashion.
As for the JVC PC-200,since the speakers attached to it say 6 ohm,can anyone tell me if I can assume that the amp is also optimised for a 6 ohm load?From what I understand,a lower ohm rating for a speaker means it will be louder than a higher rated one all other variables being identical.However,what would happen if I tried a 8 ohm speaker with a 6 ohm amp?Which mismatch will hurt the speakers and which mismatch could blow the amp?
jovie --i think that none of the backplates list the ohm ratings -- however if you look for a little imprint exactly nearest to the spot of the jacks/plugs where the speakers attach -- the ohm rating should be right there
quote:
As for the JVC PC-200,since the speakers attached to it say 6 ohm,can anyone tell me if I can assume that the amp is also optimised for a 6 ohm load?From what I understand,a lower ohm rating for a speaker means it will be louder than a higher rated one all other variables being identical.However,what would happen if I tried a 8 ohm speaker with a 6 ohm amp?Which mismatch will hurt the speakers and which mismatch could blow the amp?
A higher ohm rating will as general rule not hurt the amp but you will have to drive the volume louder to hear it. Most boomboxes will drive a 4-8 ohm load no problem. The reason that the lower ohm rating hurts amp is the heat. Because of the lower ohm rating there is less resistance allowing more voltage to pass through at lower volumes. This also increases the amperage going through the circuit thus increasing the heat, leading to failure. As I noted before, your PC-200 is not like having a Yorx or Lennox Boombox with parts from Timbuktoo or something. It still has quality parts and thus should handle 4 ohms with no problem. As a general rule it's 2 up, 2 down. Example...if your amp is rated to 6 you can go 4 to 8.
BTW...Gotta try that trick on the DT-680! Didn't know that!
Well i dono about all tha technical mumbojumbo but i set my PC-200 with 6 external speakers +the 2 origional speakersand it sounds so good i nearly cryed the day i did it,No amps,no reserch,just took what i had and whala turned it into a god. dono what the ohms,amps,watts or any thing is i just know its good.I would upload an image but i dono how to do it with Vista,hate this new tech,happy with my mac classic.
