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EP2500 on fronts...

4K views 30 replies 6 participants last post by  DisTreSs 
#1 ·
Just a quick question:

I was wondering, in anticipation of my first sub build, could I go ahead and get a EP2500 -saw one used for 225€ which seems reasonable to me... isn't it?- and hook it up to my mains?
They're B&W N803s so I'm not willing to take any chances.
The amp is 2x450W at 8Ohm so plenty of grunt still but I suppose THD will be higher than more conventional speaker amps?

Sorry about opening a new thread on this, but my responses to my own n00b DIY thread are still pending approval and I need to know this rather sooner than later
 
#2 ·
Absolutley, I run pro amps on my HT and it will be fine and should sound great. Just be carefull not to overdrive and distort the signal and you will be happy, I was.:yay:
 
#3 ·
Running an external amp on the mains is always a good idea, it relieves the load on the receivers power supply so it can drive the other channels better. However in your case 450watts is more power then the 803's can handle so be careful how hard you drive them.
 
#4 ·
Thx very much, both of you, for your replies!

I realise 450W is a lot at 8Ohm, but I am even more worried (even though B&W offer pretty stable resistance values) that at one point the amp will only get a load smaller than 4Ohms which would powerslam my speakers with even more serious wattage....:hide:

Still, if I don't dial up too much I guess I'll be fine.

So is 225€ (300 USD, 176GBP) a reasonable second-hand price for one of these??

(Yeaaay, I can post directly now!!! :D Will have to rewrite the answers I gave in my original thread that didn't get posted though :( )
 
#5 ·
The 803's are very nice speakers (I'm jealous) I would not worry about it too much. simply set your Crossover high enough that they dont get anything below 30Hz any you'll be fine.
The price seems reasonable, Go for it!
 
#6 ·
Thx again Tony!!

The N803's came at a price that's for sure...
Till this day (since 2001) I haven't had a chance to upgrade anything in the HT because of them, even though they were discounted demo models...
My surround speakers are still old pioneer speakers from my very first 'HiFi'-set way back when... :jiggy:

But hey, it'll be a cold day in hell before anyone pries these babies from my cold dead fingers :boxer: They've proven to be worth every penny...

The sub I'm planning on is actually my first upgrade audio-wise in a looong time so I'm hoping for some great results...
I've actually tried posting in my other topic again, but still nothing.... grrrrrr.... what gives?
How come I can post here but not there...
 
#7 · (Edited)
Well, seeing as I still can't post in the other thread thought I'd post a question I had about the sub in here... :devil:

Would a combination of an EP2500 with a Tempest-X and a sizeable bit of sonotube (not LLT but still large enough) beat the pants of an eD A5-350 with 550W amp or an MFW15 and such?

That's all I really want: assemble a sub that performs like the ones in the US for the price that you guys pay in the US ;)
 
#8 ·
Well I owned the A5-350 and although it is a nice sub I was a bit dissapointed. I had to wait quite awhile for the sub and I think that maybe my anticapation made me feel that it should have been better. I also had problems with the driver and the amp. They did fix those problems for me but in the end I sold it. I don't know enough about the Tempest but I run the EP2500 with a sealed sub and I am very happy with the sound. I stuck with ED for the driver and used the 130v.2 in a small enclosure. I think you would be fine with what you are thinking of for the amp and maybe someone with more experience with the tempest will chime in. Good luck.:T
 
#9 ·
thx very much for your reply!
I was actually looking into importing an a5-350 which is why I keep using it as my base of comparison at least price-wise since I haven't heard it of course.

I am aware that eD suffered a setback with the amps, but all should be well now. I'm surprised to hear that, even after it got fixed, you think it didn't live up to expectations. Even more surprised though that you felt more happy with the a sealed 12" with limited XMax compared to the ported 15" whopper ;)
Maybe you like the tight sound of sealed better?
It's good to hear the EP2500 has so much on offer though.

Anyway, I calculated that for 1000$ I could get the A5-350 delivered at my doorstep. But if I'm able to make a sub that rivals with that for 850$ (amp, driver, tube, MDF and parts), I'd be more than thrilled about it! I'll even pay as much as 1000$ to have a DIY sub if I know it'll blow the A5 or MFW out of the water :D
The lady of the house on the other hand seems to prefer challenging me to keeping the budget the same as you guys pay in the US... 650$.... :paddle:
I'm sticking to 850$ though as being more realistic ;)
 
#10 ·
thx very much for your reply!
I was actually looking into importing an a5-350 which is why I keep using it as my base of comparison at least price-wise since I haven't heard it of course.

I am aware that eD suffered a setback with the amps, but all should be well now. I'm surprised to hear that, even after it got fixed, you think it didn't live up to expectations. Even more surprised though that you felt more happy with the a sealed 12" with limited XMax compared to the ported 15" whopper ;)



I said that I was happy with the sound but I am adding a second sealed sub useing the Shivax 12'' in a little bigger box. I think then I will be more happy......:yes:
 
#12 ·
So I just got off the phone with the guy selling his EP2500's and I asked him about trying out the amp on my B&W's first and if I liked it I would come and get a second one for the subwoofer...
But he was adamant to NOT hook this puppy up to my B&W's cause he feared they would get destroyed.

Apparantly they hooked up a similar amp up to a hifi speaker once and after five minutes of playing, the woofer was hot as a mother**** (his words... but in dutch... :innocent:).
He will now not sell me a second one as he firmly believes that long-term (short term should be fine) exposure of my B&W's to this amp would overheat the speakers and cause permanent damage....

Purely on specs he is right of course: this amp delivers 450W@8Ohm and my speakers are only rated for 250W...
But I thought that if I dialed in the amp conservatively I would be fine, but he seems to think this won't be the case....

Now what do I do??? Will I be fine and do I get the second one despite all his advice (it's not like he has anything to gain by saying this, on the contrary) or not??? :dizzy::dizzy::dizzy:
 
#13 ·
He has no idea what he is talking about, unless the amp is not rated to drive speakers with 4ohms I wouldn't worry about it. It is just like I said earlier just make sure you have the crossover in your receiver set to be above the lowest frequency response that your B&W speakers can handle and you will be fine. Just like you said just keep the levels reasonable. Your B&Ws can easily reach reference witch would be about 50% of the amps maximum output. So if you set the amp at 50% then you should be just fine.
I should add that because your speakers can go as low as 3.2 ohms depending on the level you could be theoretically getting allot more than 450watts out of the amp but this also causes more heat generation in the amp.
 
#15 ·
thx for the insights guys.
I'm picking up one amp tomorrow since I will be needing it anyway for the sub.
Talked him down to 268$ btw ;)

Since I won't have my sub finished straight away of course, I'll have plenty of time (relatively speaking...) of testing out the amp on the B&W's as per your comforting words :yes:. I'll carefully dial it up from 0 to see how they react with different sources. If all stays well (it just has to as I would kick myself in the a$$ the rest of my life if it doesn't...) then I'll just phone him up again to buy a second one. He has 5 on sale from a rack he isn't using anymore and I'm guessing they won't all be gone the day after tomorrow ;)

Tony, my B&W's go down to 35Hz -3 dB by the way. 28Hz at -6 even :demon: so setting the amps X-over to 40-ish should do the trick I suppose since it's probably not an absolute Xover but will roll off gradually.
You'll probably understand why up till now my need for a sub was present yet nog overwhelmingly so ;)

Thxgoon, you raise an interesting point but it also got me more confused: If my Denon 3801 receiver that only puts out 105W@8Ohm can get my B&W's to reference, then why would I even need the other amp...
I've always wanted to take some of the load of the Denon because frankly, having 7 amps in there I can't believe that all amps are getting what is needed all the time from the power supply, but leaving this out of the equation, what else does the added amp do?
I mean, you always hear people talk about headroom, but if all I am doing is dialing down the EP2500 to the level of the Denon, then why the need for a more powerfull amp?
 
#16 ·
Thxgoon, you raise an interesting point but it also got me more confused: If my Denon 3801 receiver that only puts out 105W@8Ohm can get my B&W's to reference, then why would I even need the other amp...
I've always wanted to take some of the load of the Denon because frankly, having 7 amps in there I can't believe that all amps are getting what is needed all the time from the power supply, but leaving this out of the equation, what else does the added amp do?
I mean, you always hear people talk about headroom, but if all I am doing is dialing down the EP2500 to the level of the Denon, then why the need for a more powerfull amp?
You are asking the right questions! The need for more power, or for external amplification is one of the most hotly debated topics in consumer electronics. In theory, any amp operating with negligible distortion within it's design constraints will sound exactly the same as another amp under the same conditions. There are some other tricky electonic interactions between the amp and the speaker that could render sonic differences, but these are rare and hard to test. Since you already have an amp coming, do the best thing and decide for yourself. If you don't hear a difference, don't waste your money :bigsmile:
 
#24 ·
Couple things - first, a pro amp will be fine in terms of powering your main speakers. You can't "overpower" them in the sense that they are rated for 225 watts and the amp can produce 450 watts, as the amp will only deliver x amount of watts to reach a certain output level. So however loud you were listening before with your receiver required x amount of watts, and now that same x will be asked from the amp.

What I would be concerned about is the fan noise from the amp as well as the somewhat low input sensitivity. The fan you will need to mod, and as for the sensitivity, you will probably need to turn the R and L speaker preout levels up pretty high. The question then becomes which chain will create more distortion, the receiver with high preout levels and a high power, low distortion amp, or the receiver with speaker levels low and a low distortion receiver amp at most listening levels. You'll have to test and see (or should I say hear?)
 
#25 ·
Well as you can imagine, I set the amp straight to work once I got home :D

I've been tinkering with it for about an hour and below you can find my preliminary findings.
I'll start off with the set-up though:
I just played a simple whitenoise test tone from my receiver with volume setting to 0: with the amps halfway, I still had to dial up the channel level on my receiver for it to reach 75dB which to me indicates that the pre-outs lose some of the signal strength. The reason I decided to put the amps at the halfway point was that I guessed that 450W@8Ohm divided by 2 = 225W which is still safely enough within the boundries for my speakers. As long as the increase is pretty linear with those gain knobs, which it probably is, I should be ok.


The result then was quite surprising in that the sound pressure from the speakers, when playing source material that I'm used to hearing and keeping in mind that the fronts were calibrated at 75dB just as before, was now much greater than it ever was.
However, with it came the fact that mid and upper frequencies were now much more transparant which I initially liked but after some time I felt it was a bit too much and maybe overly bright.
I would not attribute this entirely to the amp though as the room I am in now has still way to much reflection to my taste and maybe this is why this got overemphasized.

When I dialed down the amps and increased the receiver's volume passed 0, the brightness seemed to be tamed somewhat but in truth I have no idea if I compensated the decrease in amp level enough by the increase of volume level on the receiver.

Anyway, take my findings so far for what they are worth as I had no time to AB properly tonight and will be conducting further experiments later. I find it strange though that theoretically the amps should be delivering the same power as the receiver at 75dB (as per the theory described in previous posts) but that they would sound much more 'loud' with source material.

If you guys have any tests you would like to see me conduct that are of a less subjective nature, please let me know and I'll see what I can do.

PS: I might have to transfer this thread as it kinda lost its link to the subwoofer aspect no? ;)
 
#27 ·
PS: I might have to transfer this thread as it kinda lost its link to the subwoofer aspect no? ;)
I moved the thread to Home Theater Components.

Thanks for the first impressions! I'd follow Steve's advice and set the gains on the amp such that your level settings in the receiver are at 0. This will rule out any difference in sound as a consequence of pre amp gain. Also, try some measurements and see if 'louder' is actually louder or if it is perceived. Do you have REW installed? It would be neat to see some sweeps on one amp vs the other. Come to think of it... maybe I'll try that :bigsmile:
 
#26 ·
Setting the amp's attenuation controls halfway does not limit the output power to half. The amp can output full rated power even with the knobs nearly all the way down. Your speakers have a fixed sensitivity, and it will always require x amount of watts to achieve y level of spl. It doesn't matter what amplifier you use, if you are trying to achieve 75db at your seat, it was always require the same amount of watts. Because of this, and because you are having to turn the preout gains up, I would set the attenuation controls on the amp up higher and bring the preout levels down a bit.

Also, the EP2500 is pretty flat on the top end, so the amp is not causing your speakers to sound brighter.
 
#28 ·
Oh , so the gain control is actually not regulating voltage supply to the amp and therefore not telling the amps how many watts to deliver...?? This is a whole new way of looking at things for me but please forgive me since I'm still kinda new to it ;)

Had I known this beforehand, I doubt I would've hooked up the speakers to it :D
But now that I have, and everything is still working, I might as well continue.
I suppose the theory that the same amount of watts are drawn by the speakers to achieve 75dB at the 0-setting, is a valid one then ;)
Along those lines, it would indeed be better to hook up something like the EP2500 rather than anything else since an amp with limited output capability could clip to reach that same 75dB. Not that my Denon has or will, but another, lower rated amp might...

I will try what turning the channel level down and upping the gain will get me then as I've already run all the risk there is to run as long as I keep it to 75dB whitenoise at the listening position.
 
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