Is there something obviously wrong with my electrical?

MadFloyd

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May 30, 2010
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I've been trying to sort out a problem with lack of bass and general 'thin' sound and someone suggested it could be electrical so I thought I would post a few things about my setup and see if anyone spots something obvious.

I've got a 200 amp service that comes in to a main panel (left in the photo below) and is then distributed throughout the home to other panels. One of them is just adjacent and that's what feeds my audio system.

Panel.jpg

From the panel on the right, there is a 50 foot or so run to two Equi-tech transformers: one 15-amp for my sources, and one 20-amp for my amps.

Here is a pic of the two transformer boxes and I've opened up the one or the 20 amp circuit.
Transformers.jpg

Here is a close-up of the transformer for the 20 amp circuit so you can see some specs:
Transformer closeup.jpg

I've noticed that the 20 amp circuit feeds 4 outlets (2 duplexes) that are almost directly above it (nothing is plugged into these outlets as they are near my source components and not my amps). From there it takes a fairly long route (75 feet or so) to the duplex where I have my left amp plugged in and then from there it goes about 10 feet or so to the duplex that feeds the right amp.

There could very well be nothing wrong with the electrical and that my problem is speaker/room interaction. Here's a measurement taken a few weeks ago:

MProject.jpg
Red is the left channel; Green is the right channel.

Depending on what music I play (e.g. Aja by Steely Dan), it sometimes sounds like the three woofers on my M-Projects aren't working (but of course they are) and that I have tiny bookshelf speakers.

Anyways, if someone sees anything obvious, please point it out. I can't tell you how much I'd like to solve this issue... :)

Thanks...
 

Bruce B

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Your Equi=tech panels look nothing like mine and MikeL's. Which ones are they?

Have you put a meter on them to check the voltage?

What is the wire running from the Equi=techs to your duplexes?

Also, I split R/L channels to run on different circuits.

I think I have a 6 or 8ga. cable feeding my panel coming in.
 

Speedskater

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Sep 30, 2010
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What in the world is that weird graph?
Do you have a 'Kill-a-Watt' meter?
That's a rather small transformer, just what is connected to it?
 

audioarcher

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May 6, 2012
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1 Kva isolation transformer is too small to run amps off of. It is likely smaller than the transformer in your amps. A 10 Kva isolation transformer is more like it.
 

DonH50

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Jun 22, 2010
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1 kVA / 120 V = 8.33 A -- seems a rather low-rated transformer for a 20 A line. 20 A * 120 V = 2.4 kVA. A 20-A line is 12 AWG min (not 14 gauge). All that said, it is difficult to say if your amps are underserved without knowing how much power you are drawing under normal operation. Does it sound "lean" at all volume levels or just when played loudly?

As for the graph, need more information, like the frequency resolution in bass region, where you placed the microphone (on a tripod at ear level is usually best), etc. Can you do a sweep with at least 1/10 octave resolution or higher from say 1 kHz to 10 Hz? With both channels playing? It would be good to see the combined response to see if there are nulls impacting your sound.
 

MadFloyd

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I appreciate the responses.

Don, it feels like when I turn up the volume, the treble gets louder but not the bass.

I had a friend measure my room response and he did the sweeps per speaker. I did wonder myself what the combined response would be.

Btw, how would I measure voltage? I have balanced power coming out of the transformers and I don't know if that changes how one measures voltage...?
 

garylkoh

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IMHO 1kVA is extremely small for your power amps. I use 1kVA for the bass amp inside EACH of my smallest loudspeakers, and a 1.6kVA per channel for my larger speakers. Another thing to check would be the phase of all the woofers. Make sure that they are all in phase. Mistakes have happened. IIRC one of the members here had a woofer wired out of phase, and it took a long time to figure that out.

With a multimeter set at AC, measure the voltage between the neutral and live pins. Balanced power should measure no different from neutral to live. However, the difference is that both will measure at half the voltage when referenced to ground.
 

Bruce B

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IMHO 1kVA is extremely small for your power amps. I use 1kVA for the bass amp inside EACH of my smallest loudspeakers, and a 1.6kVA per channel for my larger speakers. .

Yeah, my Equi=tech panel has a 10kVA transformer weighing over 350lbs!
 

XV-1

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May 24, 2010
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Are you able to run the amps directly, bypassing the 1 KVA transformers?. the transformers in your amps are probably larger.

It would be interesting what difference there would be in sound.
 

MadFloyd

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Are you able to run the amps directly, bypassing the 1 KVA transformers?. the transformers in your amps are probably larger.

It would be interesting what difference there would be in sound.

No, not without an electrician's help. It sounds like I should get him in and bypass the transformer.

Anyone know if it's problematic to have all the outlets wired in series? I don't know much about electricity but I hate to think that the power supplying my amps is going through all those extra connections.
 

Speedskater

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Sep 30, 2010
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a] a 'Kill-a-Watt' meter plugs into a AC receptacle, then you plug your audio equipment into the meter. (there are other similar meters, but they are hard to find)

b] Using a calibration microphone for measurements will only give you information about the loudspeakers and the room.
 

zztop7

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Electrician's Bill Bypass

No, not without an electrician's help. It sounds like I should get him in and bypass the transformer.

Anyone know if it's problematic to have all the outlets wired in series? I don't know much about electricity but I hate to think that the power supplying my amps is going through all those extra connections.

You have 20 AMP breakers labeled for outlets in the panels [your photos].
Run two 12 gauge [or thicker 10 gauge] extension cords from two outlets [different breakers] to your amps.
Check the sound.
If the sound is the same, check your audio system.
The technical term for this: Electrician's Bill Bypass.
You can use the electrician when you know what you truly need.
zz.
 

BlueFox

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Nov 8, 2013
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Ian, based on what I have experienced, I would remove the transformers (I did not have this), have two dedicated 20 amp lines added (one for each amp), add a Shunyata Cyclops for each amp, add two Shunyata Sigma HC cables for each amp. While expensive, it fits in well with the rest of the system. If after all this you still have issues then at least you know there is no way it is power related.
 

MadFloyd

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Bud, that's a costly way to find out if the electrical is a problem. I might go that way but first I need to find out if the transformer is limiting current resulting in lack of bass.

I just purchased two 50' 10 gauge extension cords. I'm not sure it's cheaper than getting my electrician to bypass the transformer but at least I try it on my own (thanks zz).
 

BlueFox

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True, very true, but it gives you a very solid base foundation for system power that you can build on in the future. I evolved there from a single circuit for everything, to a circuit for source and a circuit for both amps, to the current three circuits. I wish I had just started with three, but that's how you learn.
 

ack

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May 6, 2010
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Ian, to answer the thread's question, I would say yes you have two very obvious issues: the 1kVA transformer and the varying speaker responses (especially in the bass). The transformer is extremely inadequate for the system, and barely adequate just for sources. I was going to suggest the bypass method, but it looks like zz beat me to it. Also refer to the emails I've sent you in the past regarding power cords' rise times - it's a similar effect with inadequately powered transformers in the middle. Even if the bypass method doesn't offer immediate gratification, you still don't want such a small transformer for the entire system. Personally, I prefer nothing between the amps and the utility, and to give an example, the bass was significantly diminished using MIT Oracle ZIII cords on my amps, versus my Shunyata CX.
 

Orb

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Sep 8, 2010
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1 kVA / 120 V = 8.33 A -- seems a rather low-rated transformer for a 20 A line. 20 A * 120 V = 2.4 kVA. A 20-A line is 12 AWG min (not 14 gauge). All that said, it is difficult to say if your amps are underserved without knowing how much power you are drawing under normal operation. Does it sound "lean" at all volume levels or just when played loudly?

As for the graph, need more information, like the frequency resolution in bass region, where you placed the microphone (on a tripod at ear level is usually best), etc. Can you do a sweep with at least 1/10 octave resolution or higher from say 1 kHz to 10 Hz? With both channels playing? It would be good to see the combined response to see if there are nulls impacting your sound.

And what is interesting is that the XA160.8 (MadFloyd owns) has an idle draw of 4.6amps as mono, so both together is 9.2amps due to its Class A design.

Madfloyd, as suggested by Speedskater it can make sense buying or borrowing a mains monitor for power usage to see what the amps are doing and may help to correlate to subjective experience-test your doing, just quick calc the limitation is potentially influencing the amps/electronics as suggested by others and Don.
Hitting that ceiling could potentially be influencing all the electronics on that mains circuit and not just the amps.
Cheers
Orb
 
Last edited:

BlueFox

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Anyone know if it's problematic to have all the outlets wired in series? I don't know much about electricity but I hate to think that the power supplying my amps is going through all those extra connections.

Yes, it is a big problem for audio. Ideally you want a short uninterrupted 10 gauge cable from the breaker to a single outlet and the end, with a single circuit for the source gear, and a single circuit for each amp.

When you have outlets wired in series on the same line you have 'resistors' in series from the breaker to whatever piece of gear is at the last outlet. These 'resistors' are increasing the DTCD loss on the line, and with the level of gear you have every fault will be exposed via sound degradation. Get the power right, and the sound will follow.
 

garylkoh

WBF Technical Expert (Speakers & Audio Equipment)
Sep 6, 2010
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And what is interesting is that the XA160.8 (MadFloyd owns) has an idle draw of 4.6amps as mono, so both together is 9.2amps due to its Class A design.

In that case, the transformer is woefully inadequate as it only has a duty cycle of 8.4A (from the picture MadFloyd posted). In this case, the transformer may also overheat. However, with a full Class A design and assuming adequate capacitance in the power supply, unless you are playing extremely loudly and continuously, the inadequate current from the wall becomes less of an issue.
 

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