Axiom Home Page Forums General Discussion Home Theater Master T

6 weeks in on the new EP 500, its really opening up now and I made input adjustments to the calibration on my Anthem AVM 60 after shutting down ARC. The ARC set my sub levels at -1db. I moved it up a notch to 0db then played some known vinyl cuts.... wow, I am amazed. What is 1 db? maybe a 20 or 30 percent increase in power to the EP500? I will say that the EP 500 is mastering my Model T's The perfect compliment.

My Gin switch EP 800 was shipped today and I will put it into service mid week next week. It won't be broken in on arrival, but I'll get the idea right off. Mojo is going to be jumped on this

Slim

Music just isnt music without a sub especially classic rock for me. The 800 with the 600 should really balance out any nulls, adding a second sub is heavenly. I never realized how important it is to let a sub break in ,but i replaced a driver in one of my small subs and it was anemic as soon as i started using it. it took about a week and then it cam alive.

I threw the gut punch switch a couple of days ago, Slim.

I temporarily have two v4 EP800s and have not found a benefit to use two for my MLP. In fact, unless very carefully tuned, two are very detrimental. There are more opportunities to get two wrong than there are to get right.

A single EP800v4 is more than adequate for a 10,000 ft^3 room. I can hit 110 dB in my space without breaking a sweat. I just hear every deep, tight, undistorted bass note no matter the gain.

Mojo , the EP800 is essentially 2 subwoofers already so yeah i can see how you wouldnt really require 2 of them together. I have a pair of 10'a on a concrete foundation that shake the walls and move the couch. A pair of 12's in my car makes the windows flex.

Really your room is 10,000 cubic feet. why so big

With the amount of power the 4 drivers produce you could probably overload most rooms.

In my 2000 foot room my Ep500 seems adequate, though that never stops the want of more power!!!

In the last couple years I've had my 500 it's never made a bad sound. To which I could easily make my old $200 specials chuff.

My room is only 4,200ft^3. Slim's is 10,000. I am extrapolating from my experience in my room and saying that a single EP800v4 should be more than adequate for a 10,000 ft^3 space.

Thats still a good sized room, i get by with half that. That being said it depends on how much stuff is taking up space in that room. For example a room that size could hold a couple rows of 4 full size seating, along with other furniture. 2 of those subs in that room seems like overkill even to a bass head like me but thats the fun of this indoor sport .

I have a 70,000 BTU gas fireplace, a laz-boy chair, a 4-seat leather couch and ottoman, a ping pong table and paintings covering 70% of the wall surfaces. The floor has thick underlay and Berber. There's room for more stuff like more speakers.

If i was closer by i could help fill the room by coming over and beatin your azz at ping pong.

I've been playing it for 38 years and I am no better than when I started. Ditto with tennis and squash.

Yeah i suck at it too and age hasnt enhanced anything. I still have to left hands when it comes to any kind of sport though i used to be quite adept at hand to glass combat many years ago.

My EP 500 is alive now, it opened up and I am amazed at the output. The gut buster will go on the adjacent wall and I will most likely adjust the level and phase to make the two sync.

I think that the additional sub will not overload the space at all, but it will certainly round out grazing space bass.

My big issue at the moment is I am having a problem with my amp shutting down due to over temperature at loud volume levels which it never did. This is new. It was always happening on the right speaker (right channels of the amp closing down). I switched the speakers side to side and now the left channel shuts down, but what is interesting is the right channel went out a couple of minutes later and I have been monitoring the termperatures of the heats sinks and the over temp occurs at 150 degrees. One speaker definitely makes the amp run hotter than the other. When I had the initial issues, the right channel was always running about 20 degrees warmer... I switched the speakers from side to side and when I went into over temp; the now left channel (the speaker from the right which ran 20 hotter) is running about 5 to 8 degrees hotter so it tripped first, but I was interested by the fact that the new temperature differential is only 5 to 10 degrees vs. a solid 20 or so. Not sure if this is due to the crossovers in the Speakers causing this or if the amp has an issue going on. This is all new, never had issues with loud playing over heating the amp. And this only occurs with a specific CD I have which is full of very dynamic mid and low range material. Never an issue with vinyl, no matter how loud I play it and how much dynamic range the material is.

Any one have any ideas?

Mojo, hows the switch? I know its new and not opened up as of yet, but initial thoughts? I'll have mine mid week

Slim, let's compare notes on the gut punch mode after you've received your sub.

CDs have a 20 to 25 dB greater dynamic range than vinyl. You may be reaching the limits of your amp. One channel could be slightly different than the other. Another possibility is the impedance of the speaker. Ask Bryston what the T's impedance and phase is up to and above 20 Khz. It could be that the CD along with the program material you are listening to is full of ultrasonic content that is taxing the amp particularly if the T's impedance dips below 4 Ohms and its phase deviates extensively from nil.

It's also possible you've cooked one of the Ts and I am sure no one ever thought that would be possible but by your own admission, you've been pushing them to the spec'd envelope.

Update; I caused the amp to shut down with vinyl tonight.

It seems that the amp is running warmer than it used to in the past. If the T's had a change in the crossover specs due to what ever; would that not cause things to go south right off?

I am wondering if this is not an amp problem... but it could well be a T issue, not sure how to approach this.

contrary to what that reviewer posted, I totally disagree. The Model T's, not Middle T's as in the review, are amazing speakers. Solid, beautiful to look at and they have unbelievable dynamic power and range.

My issue at the moment is still undetermined in origin of cause of the problem. As in everything electronic, it can be complex or very simple. I've run many tests over the weekend and at the very least, I have a lot of data points. I just don't know what is breaking down

Not sure how you are driving them but bass takes a lot of horse power and playing them full range can be taxing on a reciever even at 8 ohms never mind 4 ohms . Sorry i thought you had the middle t. Many people buy a usb fan setup to put under or on the reciever to move some air, heat kills electronics and fast.

I am bi amping the speakers at 4 ohms. 400 watts per section, so there is no under powering clipping going on. But there is a new and sudden over temperature situation going on.

i didnt suggest under powering at least i didnt intend to but if your playing loud into 4 ohm loads your drawing current and that makes heat, just add some cooling its not like your committing a sin by doing that. try a small house fan to move some extra air.

Agreed, a fan would be great, but what disturbs me is that in much warmer temperatures vs. winter conditions, I never had to use fans to cool the amp and it never went into heat shut down. Something else has occurred which is what I am trying to get to the bottom of. It's either a change in the amp or a change in the speaker crossovers or a change in a speaker driver.

So same output level and same program material? how old are the amps. I bought a used sub amp once from a guy that used in db races and it worked for about 7 months and then it failed and when i oopened it , it smelled really bad and couple of op amps were burned. Electronics deteriorate over time due to heat that goes unnoticed. I am just throwing around ideas here but maybe pop the top off the offending amp and give it the smell test. I fixed my plasma tv a couple times by sniffing around.

How does the speaker sound at lower volume levels? At higher volume levels?

How easy is it to inspect the cross-over? Looking inside the amp is also a good idea like Socketman suggested.

The T's sound perfect at either low volume or very high levels... makes no difference and I cannot hear any difference at all from what they have always played like. It's just that the amp suddenly shuts down the channels feeding the woofers.

I spent a lot of time on the phone with Bryston today, we did a lot of tests. Putting my Fluke multi meter across the inputs on the speakers feeding the woofer section, I measured 3.8 ohms and 3.3 ohms on the one which corresponds with the overheating amp channel. The shorted resistance reading on the probes of the meter is at .2 ohms, so subtracting this out from the above reading equals 3.6 and 3.1 respectively. This is DC ohms, resistive no AC impedance. If I recall, the AC reading in impedance would be slightly higher than the DC reading.

There is about a 15% difference in impedance between the two speakers in the pair, that is pretty close to the difference in the heat I am seeing on the amp. When it shuts down on one side, the temperature is hitting 150 degrees F vs. around 130 degrees on the other side. I think there has been this difference in heat as long as I can recall, but the amp is not handling it suddenly.

I pulled the three woofers from the low reading speaker today, I read 8.2, 8.4 and 8.7 DC resistive ohms on the drivers. I don't know what the proper spec is, but again to hit 4 ohm nominal, each speaker would have to be 12 ohms AC, it seems these readings are a little low. If all three were at the 8.7 range, the speaker would be more matched to the other T.

I am waiting to get information back on what my readings say. I think that if the speakers were around 9 or 10 ohms DC that would equate to around 4 ohms AC impedance.

Slim? Hello? Did you blow yourself up, mate?

I am alive and well, ears are oozing blood now.... I think I have this figured out: read PM