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PostPosted: Sat Aug 12, 2017 5:09 pm 
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Location: Thunder Bay, ON, CA
Hi guys, hate to bug but i need your help on how to properly wire 2 Pair of 4ohm Magnepan 3.7i's to 2 monoblock amps so each amp needs an 8ohm load they wont handle a 2ohm load and they each put out 600w rms @8 ohm so for me they are way more then enough for 2 pair way overkill for one pair as the amps put out 1100rms at 4 ohm. both pair are going to be my left and right channel of a stereo only system. I'm old school and dont like surround sound for music. I use to remeber how to do this but its been 20+ years since i have had to do this so If a few ppl can look closely at my attached picture (sorry for the poor diagram - you try to do that with your finger makes you look like its done by a 5yr old :-) ) and tell me the correct way diag A or B for one side to one amp or are they both wrong?
If you guys would help me out i'd be much appreciated and will gladly take a picture of my system when its finished I have some nice equipment and have wanted 2 pairs of maggies my whole life for an ultimate stereo system.

Thanks so much for everyone's help if you want to reply so i recieve it immediately you can send the proper way to my cell phone damur69@gmail.com or sms 807-252-5588 or ill just look on here a couple times a day and i'd appreciate it alot guys

My System is 2 pair of Magnepan 3.7i's Stereo Only system
2x 15" Velodyne Subs
2x Emotiva XPA 1 Gen2 Monoblocks
Sonic Frontiers Line 2 Preamplifier for controlling everything
MHDT Labs Optical to Analogue RCA Tube Pre for Mp3's
on Custom i7 HTPC for Flac etc.
Yamaha Turntable w/Project Tube 2 Pre
Samsung Blueray
Panamax Surge Suppression
Individual 15AMP Circuits for each amp and 3rd for preamp and computer tv etc.
Went all out on the spkrs Dark Cherry Oak Upgrade accents.
All wiring is OFC Copper

I've been buying equipement for the last 10 years to put this baby together as I'm not Rich just
love my music and have wanted a system like this my whole life since i was about 15 and herd my first set of magnepan tympani IVa's - Retiring alot of equipment that i no no longer need because my system is now a reality will be posting
2 carver PM1.5 monoblocks for sale on here my Audio Research M125 Tube Amp, 2x Carver PM2.0 Amps, Carver TFM 65 Amp - All is Going up for sale at decent price no Crazy asking prices just could use recovering some cash on the stuff i will no longer need or use i have amplification out the wazoo I have this Compulsion for collecting amplification that i could never possibly use in my house I guess I'm a kinda a horder or making up for lack of Something could never really figure that out when it comes to stereo sh*t LOL. I love car and home Audio.


Thanks for your help.
Mike.


Attachments:
File comment: Diagram A or B?
Emotiva Wiring for 8 ohm to mono.jpg
Emotiva Wiring for 8 ohm to mono.jpg [ 101.49 KiB | Viewed 2159 times ]
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PostPosted: Sat Aug 12, 2017 5:13 pm 
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A

-- 12 Aug 2017 21:18 --

Image


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PostPosted: Sat Aug 12, 2017 6:07 pm 
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I'm not sure you can connect 3way speakers in series without altering the predicted crossover responses. Single drivers are no problem.

I'd try parallel first, keeping an eye on the amps to see how they react to it. If the volume's not too loud, they might be fine. Maggies love current, but other than that, they're a pretty easy load relative to moving coils.

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PostPosted: Sat Aug 12, 2017 7:55 pm 
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Location: Etobicoke, ON, CA
ripblade is over complicating the situation - (A ) - your fine from the amp to speaker positive to negative then positive to negative,
polarity kinda works the same as batteries & resistors from high school physics.

don't stress, I have done this same thing before - with different amps and speakers and you will be fine - the amp will see 8 ohms

cheers


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PostPosted: Sat Aug 12, 2017 8:49 pm 
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pick the wiring diagram you think is right, but check it with your ohms setting on meter and see what it says.
remembering it is going to be a nominal reading, but you will at least see results of single speaker at 4 or close, then wired, 8 or close.

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PostPosted: Sun Aug 13, 2017 1:56 am 
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Location: Richmond Hill, ON, CA
To OP
I am not sure why you want 2 pair of 3.7
But I have seen people using MC1.2kW to drive one 3.7 which is not really overkill for maggies.


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PostPosted: Sun Aug 13, 2017 5:15 am 
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You may still get low resistance with speakers connected,
Impedance varies with different frequencies.

-- 13 Aug 2017 13:15 --

You may still get low resistance with speakers connected,
Impedance varies with different frequencies.


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PostPosted: Sun Aug 13, 2017 5:26 am 
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Natalie - has ignored the fact that both speakers are the same, So the impedance/frequency curve will be the same, its a mute point.


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PostPosted: Sun Aug 13, 2017 6:06 am 
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No two speakers are the same.
Are two 2017 mustangs the same?
are twins the same?


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PostPosted: Sun Aug 13, 2017 11:06 am 
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alladione wrote:
ripblade is over complicating the situation
Perhaps....I do tend to do that lol. But I can't see how the 2nd tweeter doesn't see the 1st one and it's crossover, as well as it's own. I've drawn a simplified schematic (badly) to show what I mean. The dotted lines represent a normal parallel connection. With this removed and connecting the speakers in series, it can be seen that the 2nd filter (C2) follows the first tweeter (T1), etc.

I know that series crossovers exist, but their design parameters are fairly complex, which is why parallel networks predominate. One can't simply take the components of a parallel network, hook them up in series and expect the result to be the same.

Attachment:
series tweeters.gif
series tweeters.gif [ 1.71 KiB | Viewed 1870 times ]

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PostPosted: Sun Aug 13, 2017 12:24 pm 
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Location: Mississauga, ON, CA
Mike your 1st diagram is correct for hooking up 2 speakers in series giving you combined resistance of speaker A + speaker B.
Polarity is correct as well.

P.S. you can never have too much power running big Maggies. I run 1.6QR with solid (Bryston made) 400 W a channel into 4 ohms. Friend runs MGIIIs with 800/channel.


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PostPosted: Sun Aug 13, 2017 1:04 pm 
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Location: Stratford, ON, CA
Hi,

Note to the OP: listen to bandy above. It's your A diagram - ONLY!

Components that offer resistance in ohms, when they are connected in series, only require that you simply add the two resistance values. If they are connected in parallel, the combined resistance is lower, which you don't want for sure. However, be mindful that the nominal resistance of any speaker varies with frequency, and the rated resistance of a speaker, whether 4, 8, or 16 ohms is only a rough approximation of the value range the speaker will present to the amp as a load. At very low frequencies, a nominally rated 8 ohm speaker may present a 2 ohm load, and at 20K it may present a 20 ohm load. I have never seen the graph of 'resistance X frequency' for maggies, but this info will be around somewhere. But you are safe to connect using Diagram A. The fact that the pairs of speakers are identical will help a lot.

Cheers,
David Neice

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PostPosted: Sun Aug 13, 2017 1:30 pm 
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buybye88 wrote:
Hi,

Note to the OP: listen to bandy above. It's your A diagram - ONLY!

Components that offer resistance in ohms, when they are connected in series, only require that you simply add the two resistance values. If they are connected in parallel, the combined resistance is lower, which you don't want for sure. However, be mindful that the nominal resistance of any speaker varies with frequency, and the rated resistance of a speaker, whether 4, 8, or 16 ohms is only a rough approximation of the value range the speaker will present to the amp as a load. At very low frequencies, a nominally rated 8 ohm speaker may present a 2 ohm load, and at 20K it may present a 20 ohm load. I have never seen the graph of 'resistance X frequency' for maggies, but this info will be around somewhere. But you are safe to connect using Diagram A. The fact that the pairs of speakers are identical will help a lot.

Cheers,
David Neice


All valid points, however Magnepan 3.7i have impedance above 4 ohms between lowest frequencies and 1k with peak about 8 ohms between 1k and 2 k, then mostly just below 4 ohm for the rest. They do not behave as typical box speaker.


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PostPosted: Sun Aug 13, 2017 2:14 pm 
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natalie wrote:
No two speakers are the same.
Are two 2017 mustangs the same?
are twins the same?


If you saying that as the same brand and model roll off the line there are minute difference because each componant in the cross over and the drivers are something different between their ohm tolerance range?
Sure.
That has little or nothing to do with the question.
If the nominal rating of his objective set up is with in the amp's capability, it will react the same way it would react to any multiple driver system at nominal 8 ohm over the spectrum.
Do you think M-pans engineers designed these so badly that over the spectrum, the variance would endanger an appropriately rated amp?

Your other comparisons desearve nothing more than :roll:

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PostPosted: Sun Aug 13, 2017 4:09 pm 
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For crying out loud, don't ever connect the speakers in parallel as that will reduce the load the amps see down to 2 ohms, which could one day spell disaster for the amps, and perhaps the speakers also. Let it be clear, connecting speakers in parallel will half the resistance the amps see; connecting the speakers in series will double the resistance that the amps see. To keep the resistance same, one would need four speakers per channel, two sets in series, those then attached to each other in parallel.

Bolly's "Wiring 2 Speakers in Series" diagram (bottom left hand side) is the only safe way to go!!!

That said, this attempted endeavour absolutely BEGS the QUESTION: Why on earth do you think that it could possibly be a good idea to to use two sets of Maggies? By now you should realize that you can buy a pair of high quality 4-ohm power resistors and place them in series with a single pair of Maggies and you should be up and running. I would highly recommend first checking with Magnepan and Emotiva just to be sure, and take the time to ask them for a recommended brand/type of power resistor, if any, or, phone The Parts Connection.

The big flaw in your original plan is placing the Maggies relative to one another. I'm sure the people at Magnepan will tell you that there is no practical way to arrange pairs per side without completely screwing up the imaging. The best you could do is disable one of the tweeters per side. Big can of worms! You could try the panels with the tweeters side by side, but they weren't designed to be used this way and you would be throwing away a lot of their best design features. Your best bet is simply getting two of Magnepan's dedicated bass panels. That would cost you $2000 - a lot less than what you would get from selling one pair of the Maggies. I would sell the Velodynes also, as they will be much more difficult to pair properly with the 3.7's. I lean toward synergy and accuracy than to bombast; if you are completely into earth-shattering bass, then keep the Velodynes, but learn how to best protect your hearing.

Seeing as you already have a great pre-amp in the Sonic Frontiers, you could sell the Emotiva's and step up to Sonic Frontiers amplification. It can be adjusted internally for either 4 or 8 ohm loads. Ask Chris when you phone The Parts Connection. Another step up would be to move up to a Bryston amp. Wendell Dillar of Magnepan recommends high current solid state amplification and has been using only Bryston amps at the audio shows for many years. Personally, I own units of all three brands and can attest to how well they all work together, and also with Quad esl's. Of course, it's your call; I just don't want to see you damage anything or spend any more than is necessary, which I believe you already have. Don't give your for sale units away, get fair price and be patient. For now, all you should have to do is buy a pair of quality resistors. Settle in with one pair of Maggies and figure out what you are hearing and how to improve it. See the Cardas website for properly setting up speakers in various size rooms. 3.7i's are definitely keepers! Remember, you will always be on a learning curve; I hope it takes a big jump for you soon. I will check back tomorrow to see if you need further clarity. Cheers!


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