Home |
Search |
Today's Posts |
|
UK diy (uk.d-i-y) For the discussion of all topics related to diy (do-it-yourself) in the UK. All levels of experience and proficency are welcome to join in to ask questions or offer solutions. |
Reply |
|
LinkBack | Thread Tools | Display Modes |
#1
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
Still fettling my Akai stero system.
Base unit with tape is now working after new fuse inserted. CD transport naffed - checked by trying on other system. So I have decided to chuck the second partly broken stereo stack and keep the speakers. However, just realised that the speakers are 6 ohm, and the connectors on the back of the amp say Speakers (6-16ohm) and Surround Speakers (8-16 ohm). Grr....gnarghh....there goes my plan to use the spare set of speakers for surround speakers. So is running 6 ohm speakers on an 8-16 ohm speaker circuit likely to blow the speakers or the amplifier? Is there an easy way to uprate the speakers to 8 ohm? Otherwise I'll probably have to chuck them. Apart from anything else I think that 6 ohm speakers are fairly rare, and that most speakers come in at 8 ohm. Cheers Dave R -- No plan survives contact with the enemy. [Not even bunny] Helmuth von Moltke the Elder (\__/) (='.'=) (")_(") |
#2
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
Speaker impedance is pretty nominal. I'd not expect a decent amp to be
worried about 6, rather than 8 ohms. Unless being driven flat out. -- *Why is it that to stop Windows 95, you have to click on "Start"? Dave Plowman London SW To e-mail, change noise into sound. |
#3
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
"Dave Plowman (News)" wrote in message ... Speaker impedance is pretty nominal. I'd not expect a decent amp to be worried about 6, rather than 8 ohms. Unless being driven flat out. For various values of 'decent amp' :-) Can't turn the damn thing up more than about 30% without annoying the neighbours. 50% and my ears start to bleed!" Thanks - will give it a go. -- No plan survives contact with the enemy. [Not even bunny] Helmuth von Moltke the Elder (\__/) (='.'=) (")_(") |
#4
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
On Fri, 17 Feb 2012 16:09:52 -0000, "David WE Roberts"
wrote: However, just realised that the speakers are 6 ohm, and the connectors on the back of the amp say Speakers (6-16ohm) and Surround Speakers (8-16 ohm). Grr....gnarghh....there goes my plan to use the spare set of speakers for surround speakers. So is running 6 ohm speakers on an 8-16 ohm speaker circuit likely to blow the speakers or the amplifier? Is there an easy way to uprate the speakers to 8 ohm? Otherwise I'll probably have to chuck them. Apart from anything else I think that 6 ohm speakers are fairly rare, and that most speakers come in at 8 ohm. 6ohm speaker were common on Japanese midi systems at the time - I have a set of old 6ohm Aiwa boxes which work happily on a nominal 8ohm amp. The impedence is only nominal anyway - speaker impedance varies with frequency - just dont bang 60W through them. If you're using them as surround speakers, just wire them up and try them but you'll likely find they're a bit on the loud side. You could try strangling them a bit with a series 4ohm resistor, but it might affect response - perhaps not a problem in surround use. |
#5
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
On Feb 17, 4:09*pm, "David WE Roberts" wrote:
Still fettling my Akai stero system. Base unit with tape is now working after new fuse inserted. CD transport naffed - checked by trying on other system. So I have decided to chuck the second partly broken stereo stack and keep the speakers. However, just realised that the speakers are 6 ohm, and the connectors on the back of the amp say Speakers (6-16ohm) and Surround Speakers (8-16 ohm). Grr....gnarghh....there goes my plan to use the spare set of speakers for surround speakers. So is running 6 ohm speakers on an 8-16 ohm speaker circuit likely to blow the speakers or the amplifier? Is there an easy way to uprate the speakers to 8 ohm? Otherwise I'll probably have to chuck them. Apart from anything else I think that 6 ohm speakers are fairly rare, and that most speakers come in at 8 ohm. Cheers Dave R Its a nonissue upto around 3/4 max power output. Above that, what happens depends. On an old totally unprotected amp, at max output it could fry the amp. NT |
#6
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
On Feb 17, 4:09*pm, "David WE Roberts" wrote:
Still fettling my Akai stero system. Base unit with tape is now working after new fuse inserted. CD transport naffed - checked by trying on other system. So I have decided to chuck the second partly broken stereo stack and keep the speakers. However, just realised that the speakers are 6 ohm, and the connectors on the back of the amp say Speakers (6-16ohm) and Surround Speakers (8-16 ohm). Grr....gnarghh....there goes my plan to use the spare set of speakers for surround speakers. So is running 6 ohm speakers on an 8-16 ohm speaker circuit likely to blow the speakers or the amplifier? Is there an easy way to uprate the speakers to 8 ohm? No. NT |
#7
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
wrote in message news On Fri, 17 Feb 2012 16:09:52 -0000, "David WE Roberts" wrote: However, just realised that the speakers are 6 ohm, and the connectors on the back of the amp say Speakers (6-16ohm) and Surround Speakers (8-16 ohm). Grr....gnarghh....there goes my plan to use the spare set of speakers for surround speakers. So is running 6 ohm speakers on an 8-16 ohm speaker circuit likely to blow the speakers or the amplifier? Is there an easy way to uprate the speakers to 8 ohm? Otherwise I'll probably have to chuck them. Apart from anything else I think that 6 ohm speakers are fairly rare, and that most speakers come in at 8 ohm. 6ohm speaker were common on Japanese midi systems at the time - I have a set of old 6ohm Aiwa boxes which work happily on a nominal 8ohm amp. The impedence is only nominal anyway - speaker impedance varies with frequency - just dont bang 60W through them. If you're using them as surround speakers, just wire them up and try them but you'll likely find they're a bit on the loud side. You could try strangling them a bit with a series 4ohm resistor, but it might affect response - perhaps not a problem in surround use. Thanks - that suggests to me that if I am wiring up a 4 speaker system then the ones furthest from the listening area and with the longest speaker cable runs should be the surround ones :-) Or alternatively the closest one so you hear the sound 'in front' and don't actively notice the fill in from the back. Or not. Err..... Well, suck it and see time :-)) -- No plan survives contact with the enemy. [Not even bunny] Helmuth von Moltke the Elder (\__/) (='.'=) (")_(") |
#8
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
On 17/02/2012 17:36, David WE Roberts wrote:
6ohm speaker were common on Japanese midi systems at the time - I have a set of old 6ohm Aiwa boxes which work happily on a nominal 8ohm amp. The impedence is only nominal anyway - speaker impedance varies with frequency - just dont bang 60W through them. If you're using them as surround speakers, just wire them up and try them but you'll likely find they're a bit on the loud side. You could try strangling them a bit with a series 4ohm resistor, but it might affect response - perhaps not a problem in surround use. Thanks - that suggests to me that if I am wiring up a 4 speaker system then the ones furthest from the listening area and with the longest speaker cable runs should be the surround ones :-) Or alternatively the closest one so you hear the sound 'in front' and don't actively notice the fill in from the back. Or not. Err..... Well, suck it and see time :-)) Don't surround systems have volume controls for the other sets of speakers? (obviously just an offset, the main control still needs to control all) |
#9
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
"Tim Streater" wrote in message ... In article , wrote: On Fri, 17 Feb 2012 16:09:52 -0000, "David WE Roberts" wrote: However, just realised that the speakers are 6 ohm, and the connectors on the back of the amp say Speakers (6-16ohm) and Surround Speakers (8-16 ohm). Grr....gnarghh....there goes my plan to use the spare set of speakers for surround speakers. So is running 6 ohm speakers on an 8-16 ohm speaker circuit likely to blow the speakers or the amplifier? Is there an easy way to uprate the speakers to 8 ohm? This question has no meaning. Likewise the answer :-) -- No plan survives contact with the enemy. [Not even bunny] Helmuth von Moltke the Elder (\__/) (='.'=) (")_(") |
#10
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
In article
, Owain wrote: On Feb 17, 4:09 pm, "David WE Roberts" wrote: Is there an easy way to uprate the speakers to 8 ohm? You could put a 2 ohm resistance in series with each speaker. If you really, really, really wanted to. Not a good idea. Will mess up the damping factor. A transformer would be the way to go. But rather pointless. -- *Did you ever notice when you blow in a dog's face he gets mad at you? * Dave Plowman London SW To e-mail, change noise into sound. |
#11
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
On Feb 17, 4:09*pm, "David WE Roberts" wrote:
Still fettling my Akai stero system. Base unit with tape is now working after new fuse inserted. CD transport naffed - checked by trying on other system. So I have decided to chuck the second partly broken stereo stack and keep the speakers. However, just realised that the speakers are 6 ohm, and the connectors on the back of the amp say Speakers (6-16ohm) and Surround Speakers (8-16 ohm). Grr....gnarghh....there goes my plan to use the spare set of speakers for surround speakers. So is running 6 ohm speakers on an 8-16 ohm speaker circuit likely to blow the speakers or the amplifier? No. Just try it and see,but don't expect greatness, particularly with more crossover circuits. Is there an easy way to uprate the speakers to 8 ohm? Otherwise I'll probably have to chuck them. Disconnect any crossovers so that you are just running a mid-range driver. Apart from anything else I think that 6 ohm speakers are fairly rare, and that most speakers come in at 8 ohm. Don't worry, be happy. |
#12
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
On Feb 17, 6:09*pm, Clive George wrote:
On 17/02/2012 17:36, David WE Roberts wrote: 6ohm speaker were common on Japanese midi systems at the time - I have a set of old 6ohm Aiwa boxes which work happily on a nominal 8ohm amp. The impedence is only nominal anyway - speaker impedance varies with frequency - just dont bang 60W through them. If you're using them as surround speakers, just wire them up and try them but you'll likely find they're a bit on the loud side. You could try strangling them a bit with a series 4ohm resistor, but it might affect response - perhaps not a problem in surround use. Thanks - that suggests to me that if I am wiring up a 4 speaker system then the ones furthest from the listening area and with the longest speaker cable runs should be the surround ones :-) Or alternatively the closest one so you hear the sound 'in front' and don't actively notice the fill in from the back. Or not. Err..... Well, suck it and see time :-)) Don't surround systems have volume controls for the other sets of speakers? (obviously just an offset, the main control still needs to control all) Psuedo surround systems (mixed rear channels) can be had cheaply, a balance pot would double the cost of the surround componentry. Stop being silly and stuff a moth-eaten pullover in the talking-box. |
#14
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
"Brian Gaff" wrote in message ... The thing is the 6 or 8 or whatever ohm is merely a very approximate thing. If they are multi unit then the impedance will vary at different frequencies and often be capacitive and have strange reactive elements as well. What really matters is how efficient they are, ie wats in for sound out as very inefficient ones need more driving of course. I'd not be too worried. Assuming a properly designed amplifier you should not have any issues. You say the cassette is duff, often cleaning and a new set of belts can work wonders if the system basically works and does not have teeth missing on gears or perished rubber bits. snip Thanks for all the responses. Couple of things: It is the CD transport which is duff - fails to recognise a loaded CD and the control buttons only partially work. Given that I have two identical systems it is not worth any major effort to fix this. Took the cover off, looked inside, put cover back on, queued for recycling. The good CD transport works with both stacks. The bad CD transport works with neither. People are getting all enthusiastic about 'dececnt amps' and 'crossovers' (which I assume are the links on more expensive speakers which connect two sets of terminals for single wiring if the speakers are capable of bi-wiring). Then again it could be something else :-) The amp is an Akai TP-570 which is an integral part of a pseudo-component stack system linked together with ribbon cables. It gets all soggy and hard to light if any component is missing such as the duff CD transport. The speakers are Akai SR-570 with a single pair of speaker wire clips on the back. Maximim input power 50W Impedance 6 ohm. The whole system is built to a budget (low). So I assume that the amplifier doesn't really come under the classification of 'decent amp' and all sorts of compromises may have been made to met the target budget. I bought two identical systems for the kids about 18 years ago after auditioning a load of different cheapo integrated midi systems. I was impressed by the sound quality then and it still sounds good today. Not a patch on a serious stereo with serious speakers but remarkably good for the price point. The kids (now not kids to anyone but their parents) have moved on and discarded these systems after many years of use and I am sorting out which bits are still good, prior to installing in the shed at some future time, donating to a charity shop, or recycling. I was hoping to get one system which wasn't working back into working order so it could be passed on. Replaced a blown fuse in the main amplifier/tape drive/control box and this now works. However the CD transport is banjaxed so the stack will go to the recycler - no real value in an 18 year old stack stereo which can't even play CDs. Because the system has a 'surround sound' option I was considering keeeping the second set of speakers and wiring them in. I will do this now I know that I shouldn't be too worried about connecting nominal 6 ohm speakers to a nominal 8 ohm amp output. I do wonder in passing why the system doesn't support the 6 ohm speakers which come with it as surround sound speakers, but hey - no big problem. Cheers Dave R -- No plan survives contact with the enemy. [Not even bunny] Helmuth von Moltke the Elder (\__/) (='.'=) (")_(") |
#15
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
On Fri, 17 Feb 2012 16:24:55 -0000, David WE Roberts wrote:
"Dave Plowman (News)" wrote in message ... Speaker impedance is pretty nominal. I'd not expect a decent amp to be worried about 6, rather than 8 ohms. Unless being driven flat out. For various values of 'decent amp' :-) Can't turn the damn thing up more than about 30% without annoying the neighbours. 50% and my ears start to bleed!" Thanks - will give it a go. The 6 ohm speakers will be even louder than the 8 ohm for a given volume setting; I don't know by how much. -- Peter. The gods will stay away whilst religions hold sway |
#16
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
PeterC wrote:
On Fri, 17 Feb 2012 16:24:55 -0000, David WE Roberts wrote: "Dave Plowman (News)" wrote in message ... Speaker impedance is pretty nominal. I'd not expect a decent amp to be worried about 6, rather than 8 ohms. Unless being driven flat out. For various values of 'decent amp' :-) Can't turn the damn thing up more than about 30% without annoying the neighbours. 50% and my ears start to bleed!" Thanks - will give it a go. The 6 ohm speakers will be even louder than the 8 ohm for a given volume setting; I don't know by how much. almosyt indetectable. about 1.5dB |
#17
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
On Sat, 18 Feb 2012 11:27:01 -0000, "David WE Roberts"
wrote: I do wonder in passing why the system doesn't support the 6 ohm speakers which come with it as surround sound speakers, but hey - no big problem. 16ohms in the rears were a common thing - afaics it's just a cheap way of ramping down the output of the surrounds without any more circuitry - down to a price, as you say. |
#18
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
On Feb 18, 11:27*am, "David WE Roberts" wrote:
"Brian Gaff" wrote in message ... The thing is the 6 or 8 or whatever ohm is merely a very approximate thing. If they are multi unit then the impedance will vary at different frequencies and often be capacitive and have strange *reactive *elements as well. What really matters is how *efficient they are, ie wats in for sound out as very inefficient ones need more driving of course. I'd not be too worried. Assuming a properly designed amplifier *you should not have any issues. You say the cassette is duff, often cleaning and a new set of belts can work wonders if the system basically works and does not have teeth missing on gears or perished rubber bits. snip Thanks for all the responses. Couple of things: It is the CD transport which is duff - fails to recognise a loaded CD and the control buttons only partially work. With horizontal players there is a risk of fluff getting on the lens which may prevent it from focussing. Given that I have two identical systems it is not worth any major effort to fix this. Took the cover off, looked inside, put cover back on, queued for recycling. The good CD transport works with both stacks. The bad CD transport works with neither. People are getting all enthusiastic about 'dececnt amps' and 'crossovers' (which I assume are the links on more expensive speakers which connect two sets of terminals for single wiring if the speakers are capable of bi-wiring). Then again it could be something else :-) The amp is an Akai TP-570 which is an integral part of a pseudo-component stack system linked together with ribbon cables. It gets all soggy and hard to light if any component is missing such as the duff CD transport. Zippo lighter fluid seems to be most volatile. ;-) The speakers are Akai SR-570 with a single pair of speaker wire clips on the back. Maximim input power 50W Impedance 6 ohm. The whole system is built to a budget (low). So I assume that the amplifier doesn't really come under the classification of 'decent amp' and all sorts of compromises may have been made to met the target budget. I bought two identical systems for the kids about 18 years ago after auditioning a load of different cheapo integrated midi systems. I was impressed by the sound quality then and it still sounds good today. Not a patch on a serious stereo with serious speakers but remarkably good for the price point. It was done. The kids (now not kids to anyone but their parents) have moved on and discarded these systems after many years of use and I am sorting out which bits are still good, prior to installing in the shed at some future time, donating to a charity shop, or recycling. Your CD transports may be of better standard than anything today which doesn't cost an arm-an'-a-leg. I was hoping to get one system which wasn't working back into working order so it could be passed on. Replaced a blown fuse in the main amplifier/tape drive/control box and this now works. However the CD transport is banjaxed so the stack will go to the recycler - no real value in an 18 year old stack stereo which can't even play CDs. Because the system has a 'surround sound' option I was considering keeeping the second set of speakers and wiring them in. I will do this now I know that I shouldn't be too worried about connecting nominal 6 ohm speakers to a nominal 8 ohm amp output. I do wonder in passing why the system doesn't support the 6 ohm speakers which come with it as surround sound speakers, but hey - no big problem. Cheers Dave R -- No plan survives contact with the enemy. [Not even bunny] Helmuth von Moltke the Elder (\__/) (='.'=) (")_(") |
#19
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
In message , Tim
Streater writes In article , "David WE Roberts" wrote: "Tim Streater" wrote in message ... In article , wrote: On Fri, 17 Feb 2012 16:09:52 -0000, "David WE Roberts" wrote: However, just realised that the speakers are 6 ohm, and the connectors on the back of the amp say Speakers (6-16ohm) and Surround Speakers (8-16 ohm). Grr....gnarghh....there goes my plan to use the spare set of speakers for surround speakers. So is running 6 ohm speakers on an 8-16 ohm speaker circuit likely to blow the speakers or the amplifier? Is there an easy way to uprate the speakers to 8 ohm? This question has no meaning. Likewise the answer :-) Were you imagining that I posted an answer? 1) The ohms rating of a speaker is only a guide, since it tends to vary with frequency. 2) AFAIK, any decent amp is unconditionally stable under any load. I think that's what the bumf for my Quad 303 (vintage 1970) claims, anyway. So I see no reason that it should matter. The more the speaker's ohms rating matches the output impedance of the amp, the more power will be available for the speakers - AFAIK. However there are I think some here who've actually designed this stuff so I defer to them. The amplifier's output will be essentially a voltage source, and its impedance will probably be only a small fraction of an ohm. A 6 ohm speaker will draw around 8/6ths of the 8 ohm current, and the power will be 8/6 squared more (appx 1.78 times more). But whether it sounds louder probably largely depends on the design of the speaker. You may need to reduce the volume control setting. Also, even at the same audible volume, I believe that the distortion performance might not be quite as good. Personally, I doubt if anyone would know the difference. -- Ian |
#20
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
On Feb 19, 10:59*pm, Ian Jackson
wrote: In message , Tim Streater writes In article , "David WE Roberts" wrote: "Tim Streater" wrote in message ... In article , wrote: On Fri, 17 Feb 2012 16:09:52 -0000, "David WE Roberts" wrote: However, just realised that the speakers are 6 ohm, and the connectors on the back of the amp say Speakers (6-16ohm) and Surround Speakers (8-16 ohm). Grr....gnarghh....there goes my plan to use the spare set of speakers for surround speakers. So is running 6 ohm speakers on an 8-16 ohm speaker circuit likely to blow the speakers or the amplifier? Is there an easy way to uprate the speakers to 8 ohm? This question has no meaning. Likewise the answer :-) Were you imagining that I posted an answer? 1) The ohms rating of a speaker is only a guide, since it tends to vary with frequency. 2) AFAIK, any decent amp is unconditionally stable under any load. I think that's what the bumf for my Quad 303 (vintage 1970) claims, anyway. So I see no reason that it should matter. The more the speaker's ohms rating matches the output impedance of the amp, the more power will be available for the speakers - AFAIK. However there are I think some here who've actually designed this stuff so I defer to them. The amplifier's output will be essentially a voltage source, and its impedance will probably be only a small fraction of an ohm. A 6 ohm speaker will draw around 8/6ths of the 8 ohm current, and the power will be 8/6 squared more (appx 1.78 times more). But whether it sounds louder probably largely depends on the design of the speaker. You may need to reduce the volume control setting. Also, even at the same audible volume, I believe that the distortion performance might not be quite as good. Personally, I doubt if anyone would know the difference. -- Ian It will depend on the relative sensitivities of the speakers and the precise design of the amplifiers. It's not even worth the trouble investigating what chip is used, it really is a matter of connecting it up and ensuring that the background speakers aren't intrusive or out of phase with the front speakers. If the back speakers are intrusive or distorting at what is a usable front speaker level then some resistance requires adding to the rear. Cheap co-axial wire is most suitable for remote speaker connects and simple ellipticals or dual cone ellipticals work well for this. |
#21
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
In article
, thirty-six wrote: Cheap co-axial wire is most suitable for remote speaker connects and simple ellipticals or dual cone ellipticals work well for this. Co-ax for speakers? You live and learn. -- *When the going gets tough, the tough take a coffee break * Dave Plowman London SW To e-mail, change noise into sound. |
#22
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
On 20/02/2012 10:38, Dave Plowman (News) wrote:
In article , wrote: Cheap co-axial wire is most suitable for remote speaker connects and simple ellipticals or dual cone ellipticals work well for this. Co-ax for speakers? You live and learn. It wouldn't surprise me if some power amplifiers reacted to having coax wire used to connect to speakers by oscillating wildly. You really want the equivalent of about 1mm^2 cross section of copper (or more) in each wire of a decent speaker cable intended to preserve bass response. Basic figure of 8 speaker cable using annealed copper is fine. You don't need stuff hand spun by mermaids in an oxygen free atmosphere. -- Regards, Martin Brown |
#23
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
|
#24
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
Co-ax for speakers? You live and learn.
It wouldn't surprise me if some power amplifiers reacted to having coax wire used to connect to speakers by oscillating wildly. You really want the equivalent of about 1mm^2 cross section of copper (or more) in each wire of a decent speaker cable intended to preserve bass response. Basic figure of 8 speaker cable using annealed copper is fine. You don't need stuff hand spun by mermaids in an oxygen free atmosphere. Nope!, you need the stuff thats woven by Rhine maidens by Moonlight... Like this one.. http://www.russandrews.com/product.a...¤cy=GBP& pf_id=3184&customer_id=PAA2011022512543FKBMIBCRHXT DUCCY if the budget doesn't stretch to that then Maplins and or richer sounds do a decent one for around a quid a metre.. Basic idea ids a figure of "8" type cable, the more copper therein the better.. I wouldn't use co-ax or CAT 5 for that matter. If you cannot find that in those shops then try your electrical wholesalers some do that sort. Failing all that the 2.5 Twin and earth or bigger, is usable in a lot of instances.... -- Tony Sayer |
#25
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
On 20/02/2012 12:05, Terry Casey wrote:
In , says... I see no reason that it should matter. The more the speaker's ohms rating matches the output impedance of the amp, the more power will be available for the speakers - AFAIK. However there are I think some here who've actually designed this stuff so I defer to them. The amplifier's output will be essentially a voltage source, and its impedance will probably be only a small fraction of an ohm. A 6 ohm speaker will draw around 8/6ths of the 8 ohm current, and the power will be 8/6 squared more (appx 1.78 times more). Not quite as much - but significant. Assume, for simplicity, that the amplifier output is 8V RMS. Power is E^2/R = 64/8 = 8W for an 8 ohm speaker and 64/6 = 10.66W for a 6 ohm speaker, which is an increase of a third. As the voltage is fixed, the current delivered by the amplifier also increases by 33% - so the important bit here is whether the amplifier can deliver this extra power without damage. It would be a very poor amplifier that couldn't cope. Most are supposed to shut down or decrease output power if they don't like their load. Though some will oscillate if they really can't cope with exotic low impedance speakers, silly types of audiophile cable or both. A nominal 8ohm speaker can vary in actual impedance across the audio range from something like 4 to 16 ohms or more depending on the actual frequency and how the crossovers are implemented. It is not uncommon for a nominal 8R speaker to go down to below 4R and up to 16R eg http://www.stereophile.com/content/m...r-measurements Fig 1 solid line is the impedance in ohms (with a silly number of digits on the axes) -- Regards, Martin Brown |
#26
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
On Feb 17, 5:33*pm, NT wrote:
On Feb 17, 4:09*pm, "David WE Roberts" wrote: Still fettling my Akai stero system. Base unit with tape is now working after new fuse inserted. CD transport naffed - checked by trying on other system. So I have decided to chuck the second partly broken stereo stack and keep the speakers. However, just realised that the speakers are 6 ohm, and the connectors on the back of the amp say Speakers (6-16ohm) and Surround Speakers (8-16 ohm). Grr....gnarghh....there goes my plan to use the spare set of speakers for surround speakers. So is running 6 ohm speakers on an 8-16 ohm speaker circuit likely to blow the speakers or the amplifier? Is there an easy way to uprate the speakers to 8 ohm? No. Well, you could simply put a 2 ohm resistor in series with each one. Then you'd be sure not to damage the amp. Make sure the resistor can take the power. Robert |
#27
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
In article
, Owain wrote: On Feb 20, 10:38 am, "Dave Plowman (News)" wrote: Cheap co-axial wire is most suitable for remote speaker connects Co-ax for speakers? You live and learn. Oh, it'll take mains if I've nothing better to hand... I'm sure it would. But just why you'd use a bulky expensive cable over the correct type escapes me. -- *What was the best thing before sliced bread? Dave Plowman London SW To e-mail, change noise into sound. |
#28
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
In article
, RobertL wrote: Well, you could simply put a 2 ohm resistor in series with each one. Then you'd be sure not to damage the amp. Make sure the resistor can take the power. Given a half decent power amp will have a very low output impedance, adding resistance to this somewhat negates it. -- *A fine is a tax for doing wrong. A tax is a fine for doing well* Dave Plowman London SW To e-mail, change noise into sound. |
#29
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
On Feb 20, 2:21*pm, "Dave Plowman (News)"
wrote: In article , * *RobertL wrote: Well, you could simply put a 2 ohm resistor in series with each one. Then you'd be sure not to damage the amp. *Make sure the resistor can take the power. Given a half decent power amp will have a very low output impedance, adding resistance to this somewhat negates it. So the frequency response will degrade because the impedance of the loudspeaker is not constant at all frequencies? This may be so, but I think many people use loudspeaker cables with a resistance (both wires) higher than 2 ohms. Robert |
#30
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
On 20/02/2012 14:44, RobertL wrote:
On Feb 20, 2:21 pm, "Dave Plowman wrote: In article , wrote: Well, you could simply put a 2 ohm resistor in series with each one. Then you'd be sure not to damage the amp. Make sure the resistor can take the power. Given a half decent power amp will have a very low output impedance, adding resistance to this somewhat negates it. So the frequency response will degrade because the impedance of the loudspeaker is not constant at all frequencies? More to the point the loudspeaker cone no longer goes where it is told to by the applied voltage. Look up damping factor. This may be so, but I think many people use loudspeaker cables with a resistance (both wires) higher than 2 ohms. More fool them then. On a nominally 8R system you don't really want to have anything more than 0.5R series resistance in the wire and I prefer something under 0.1R. That way the bass sounds more like the original. -- Regards, Martin Brown |
#31
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
"David WE Roberts" wrote in message ... Still fettling my Akai stero system. Base unit with tape is now working after new fuse inserted. CD transport naffed - checked by trying on other system. So I have decided to chuck the second partly broken stereo stack and keep the speakers. However, just realised that the speakers are 6 ohm, and the connectors on the back of the amp say Speakers (6-16ohm) and Surround Speakers (8-16 ohm). Grr....gnarghh....there goes my plan to use the spare set of speakers for surround speakers. So is running 6 ohm speakers on an 8-16 ohm speaker circuit likely to blow the speakers or the amplifier? Is there an easy way to uprate the speakers to 8 ohm? Otherwise I'll probably have to chuck them. Apart from anything else I think that 6 ohm speakers are fairly rare, and that most speakers come in at 8 ohm. Sucked it and saw. All seems to work O.K. AFAICT the 'surround' speakers are at a slightly lower volume than the main speakers but there isn't a gread deal in it. Whatever, it sounds nice. Shame about the other stack, but it dodn't really owe us anything. Cheers Dave R -- No plan survives contact with the enemy. [Not even bunny] Helmuth von Moltke the Elder (\__/) (='.'=) (")_(") |
#32
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
In article
, RobertL wrote: Given a half decent power amp will have a very low output impedance, adding resistance to this somewhat negates it. So the frequency response will degrade because the impedance of the loudspeaker is not constant at all frequencies? It's more the bass that suffers. The amplifier 'damps' the movement of the coil - sort of preventing it overshooting. Of course this may not be terribly apparent on a modest system. This may be so, but I think many people use loudspeaker cables with a resistance (both wires) higher than 2 ohms. IIRC, the recommendation is that the loop resistance of the cable shouldn't exceed 10% of the nominal speaker impedance. Better than that won't do any harm. In general a decent 2.5mm˛ cable will be fine for most domestic runs. -- *Nothing is foolproof to a sufficiently talented fool* Dave Plowman London SW To e-mail, change noise into sound. |
#33
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
RobertL wrote:
On Feb 17, 5:33 pm, NT wrote: On Feb 17, 4:09 pm, "David WE Roberts" wrote: Still fettling my Akai stero system. Base unit with tape is now working after new fuse inserted. CD transport naffed - checked by trying on other system. So I have decided to chuck the second partly broken stereo stack and keep the speakers. However, just realised that the speakers are 6 ohm, and the connectors on the back of the amp say Speakers (6-16ohm) and Surround Speakers (8-16 ohm). Grr....gnarghh....there goes my plan to use the spare set of speakers for surround speakers. So is running 6 ohm speakers on an 8-16 ohm speaker circuit likely to blow the speakers or the amplifier? Is there an easy way to uprate the speakers to 8 ohm? No. Well, you could simply put a 2 ohm resistor in series with each one. Then you'd be sure not to damage the amp. Make sure the resistor can take the power. Why not put the speakers a hundred yards up the road? The cable resistance would then provide the extra 2 ohms. Top tip! Bill |
#34
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
Tim Streater wrote:
This may be so, but I think many people use loudspeaker cables with a resistance (both wires) higher than 2 ohms. Unlikely. Fifty yards of bellwire? Bill |
#35
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
"Bill Wright" wrote in message ... Tim Streater wrote: This may be so, but I think many people use loudspeaker cables with a resistance (both wires) higher than 2 ohms. Unlikely. Fifty yards of bellwire? I always use virgin speaker cable. Because of the increased initial resistance. However it degrades with continuous usage. -- No plan survives contact with the enemy. [Not even bunny] Helmuth von Moltke the Elder (\__/) (='.'=) (")_(") |
#36
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
David WE Roberts :
I always use virgin speaker cable. Because of the increased initial resistance. However it degrades with continuous usage. Surely as soon as you use it, it's not virgin any more? -- Mike Barnes |
#37
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
"Mike Barnes" wrote in message ... David WE Roberts : I always use virgin speaker cable. Because of the increased initial resistance. However it degrades with continuous usage. Surely as soon as you use it, it's not virgin any more? Yes - and over time with continuous usage the resistance decreases further and further. -- No plan survives contact with the enemy. [Not even bunny] Helmuth von Moltke the Elder (\__/) (='.'=) (")_(") |
#38
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
On Feb 20, 10:38*am, "Dave Plowman (News)"
wrote: In article , * *thirty-six wrote: Cheap co-axial wire is most suitable for remote speaker connects and simple ellipticals or dual cone ellipticals work well for this. Co-ax for speakers? You live and learn. I used to use the old thin stuff meant for 405 line TV but have ran out. |
#39
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
On Feb 20, 2:19*pm, "Dave Plowman (News)"
wrote: In article , * *Owain wrote: On Feb 20, 10:38 am, "Dave Plowman (News)" *wrote: Cheap co-axial wire is most suitable for remote speaker connects Co-ax for speakers? You live and learn. Oh, it'll take mains if I've nothing better to hand... I'm sure it would. But just why you'd use a bulky expensive cable over the correct type escapes me. A reel of simple pendant wire IS generally more correct than much so- called speaker wire but when co-ax isn't conspicuous and there is a cheap source it is always my preferred speaker wiring in permanent installations. |
#40
Posted to uk.d-i-y
|
|||
|
|||
6 ohm speakers - uprate to 8 ohm?
On Feb 20, 11:14*am, Martin Brown
wrote: On 20/02/2012 10:38, Dave Plowman (News) wrote: In article , * * *wrote: Cheap co-axial wire is most suitable for remote speaker connects and simple ellipticals or dual cone ellipticals work well for this. Co-ax for speakers? You live and learn. It wouldn't surprise me if some power amplifiers reacted to having coax wire used to connect to speakers by oscillating wildly. You really want From which storybook did you find that gem? the equivalent of about 1mm^2 cross section of copper (or more) in each wire of a decent speaker cable intended to preserve bass response. Co-ax does that. Basic figure of 8 speaker cable using annealed copper is fine. In the gauges required, particularly in distant installations, basic co-axial is usually cheaper. There are advantages in the transmission of audio frequencies probably related to phase shift which occurs with 'speaker wire'. You don't need stuff hand spun by mermaids in an oxygen free atmosphere. It's still best to throw out the bell-wire even with a close-coupled installation. |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
A couple of speakers - speakers.jpg (0/1) | Woodworking Plans and Photos | |||
A couple of speakers - speakers.jpg (1/1) | Woodworking Plans and Photos | |||
OT - PC Speakers | UK diy | |||
Wireless Speakers: RCA Speakers Only Work when on Same Electrical Outlet as Transmitter / What is Problem? | Electronics Repair | |||
To uprate or not uprate ? | Electronics Repair |