bi-wiring, ohms, parallel, series... help?!

[admin_exported]

hi all,

need a bit of advice on bi-wiring my speakers. i've got the MA br2's, arcam alpha7 amp. now the amp has 2 sets of speaker terminals (sp1 and sp2) fairly standard, sp2 being switchable. what i want to do is bi-wire my speakers using sp1 for the LF and sp2 for HF. the amp states in the manual regarding sp2, 'both pairs of speakers may be driven simultaneously provided each pair is rated between 8 and 16 ohms. To avoid overheating the combined load impedence as seen by the amplifier should not fall below 4 ohms per channel'. This is where i get confused!

for a start these are the specs as per manual for the alpha7:

output power (20hz-20khz at 0.5%THD) 40W - both channels into 8 ohms, 50W - one channel into 8 ohms, 80W - one channel into 4 ohms

?????

the MA's are 6ohm, so if bi-wire them as described above, will both sp1 and sp2 get 3 1/2ohms each? or as the 2 channels are not powering 2 pairs of speakers, just one via the sp1 & 2, will the amp still only 'see' 6ohms?

just wanted to get this confusion cleared up before i go ahead.

any help will be much appreciated! thanks, Jack

 

[Anonymous]

To cut to the chase, yes you can biwire fine. Doing so won't present the amp with a load any different than with single wire. I'd start to get concerned if you were driving another pair of speakers at the same time.

 

[davejberry]

As I understand it, chosing your method would. in essence, present your amp with a load of 3 ohms per channel. Assuming that both drivers in the speaker are about 6 ohms, when both Sp1 and Sp2 are selected, the amp switches the terminals in parallel.

Just connect the seperate cable to the same terminals being sure not to cross the wires. This will give you a bi-wired speaker. I've done this with my KEFs to a Sony AV receiver and the difference was astounding. Much more open, better controlled bass and I only used QED 79 strand that I bought 20 years ago. ( i did cut back the ends to clean copper first).

 

[MattSPL]

mr.bojangles:

hi all,

need a bit of advice on bi-wiring my speakers. i've got the MA br2's, arcam alpha7 amp. now the amp has 2 sets of speaker terminals (sp1 and sp2) fairly standard, sp2 being switchable. what i want to do is bi-wire my speakers using sp1 for the LF and sp2 for HF. the amp states in the manual regarding sp2, 'both pairs of speakers may be driven simultaneously provided each pair is rated between 8 and 16 ohms. To avoid overheating the combined load impedence as seen by the amplifier should not fall below 4 ohms per channel'. This is where i get confused!

for a start these are the specs as per manual for the alpha7:

output power (20hz-20khz at 0.5%THD) 40W - both channels into 8 ohms, 50W - one channel into 8 ohms, 80W - one channel into 4 ohms

?????

the MA's are 6ohm, so if bi-wire them as described above, will both sp1 and sp2 get 3 1/2ohms each? or as the 2 channels are not powering 2 pairs of speakers, just one via the sp1 & 2, will the amp still only 'see' 6ohms?

just wanted to get this confusion cleared up before i go ahead.

any help will be much appreciated! thanks, Jack

Your 6ohm speakers present 6ohm to the amplifier regardless of whether thay are bi-wired or not.

2 pairs of 6ohm speakers wired in parallel would present the amp with a 3 ohm load.

2 pairs of 6ohm speakers wired in series would present the amplifier with a 12ohm load.

So you are not altering the load on the amp with bi-wiring except for a little extra ressistance with the extra cable run

 

[Anonymous]

thanks for the replies 🙂

ok so it seems if i use both sp1&2, i will effectively be 'splitting' the load (6ohms) into 3 ohms per channel, except each channel will only be powering half a speaker (LF or HF).

also if 2 channels are present, is it generally a better idea to use them both?

 

[Dan Turner]

mr.bojangles:
thanks for the replies 🙂

ok so it seems if i use both sp1&2, i will effectively be 'splitting' the load (6ohms) into 3 ohms per channel, except each channel will only be powering half a speaker (LF or HF).

also if 2 channels are present, is it generally a better idea to use them both?

It not quite like that. Channels are usually used to refer to your left or right. Additional speaker terminals are still connected to the same output devices within your amplifier (just with a switch to turn your sp2 terminals on/off on your alpha 7), so regardless of whether you single wire your speakers, bi-wire them into one set of output terminals, or bi-wire them using both pairs of output terminals, the load will still be 6 ohms regardless.

You can proceed with confidence - just make sure you remove the terminal links on the speakers first!

 

[Anonymous]

MattSPL:

ok so if i use sp1 to power the LF on both speakers, and sp2 to power HF, they'll be in parallel? thus the amp will still be seeing only 6ohms??

its been a long day please bear with me! 🙂

 

[Anonymous]

Dan Turner:
You can proceed with confidence - just make sure you remove the terminal links on the speakers first!

...good catch, didn't think to reinforce that one!

 

[MattSPL]

mr.bojangles:

MattSPL:

ok so if i use sp1 to power the LF on both speakers, and sp2 to power HF, they'll be in parallel? thus the amp will still be seeing only 6ohms??

its been a long day please bear with me! 🙂

Any hifi speaker is internally wired, so whatever its rated impedance, is what the amplifier see's, regardless of if you bi-wire or not.

Your speaker being a 6ohm speaker, presenting the amplifier with 2 runs of cable from the speaker is like presenting 2 x12ohm speakers. This isn't literally the case, but a 12ohm tweeter and a 12 ohm bass driver will represent a 6ohm load on the amp if you know what i mean.

 

[Anonymous]

excellent thanks people think i've sussed it. got my terms mixed up before, finally does it make any difference at all if i were to to bi-wire using the two sets of terminals, or just one?

 

[MattSPL]

mr.bojangles:excellent thanks people think i've sussed it. got my terms mixed up before, finally does it make any difference at all if i were to to bi-wire using the two sets of terminals, or just one?

You mean the 2 sets of amp terminals?
No problem using just one, but sometimes easier to use both sets.

 

[Anonymous]

yes sorry the amp terminals. great thanks again everyone 😀

 

[MattSPL]

mr.bojangles:yes sorry the amp terminals. great thanks again everyone 😀

No problem, glad to help

 

[Anonymous]

By the way, bi-wiring won't make any difference.

JOKING, joking, I have no opinion on the matter...

 

[MattSPL]

igglebert:By the way, bi-wiring won't make any difference. JOKING, joking, I have no opinion on the matter...

 

[d_a_n1979]

igglebert:By the way, bi-wiring won't make any difference.

JOKING, joking, I have no opinion on the matter...

TBH I agree with you there Igglebert but that's only because it's the Arcam alpha 7 amp.

I really don't think it's worth the hassle and extra expense (unless you've got the bi-wire cable already) in bi-wiring your M/A BR2's.

Good speakers yes but the Arcam Alpha 7 integrated amp is entry level and it's not going to give you that much difference in sound IMO.

However; if you had the budget you could look to buy the Arcam Alpha 8P power amp via eBay and then you could bi-amp the speakers which would give you a deffinate sound improvement which you'd hear straight away.