Re: Gonna Try Building a 1kW Class D Amp for Only $396
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As a test, I directed my HEPA filter fan at the stock heatsinks. I was able to turn the receiver up to +7db with no cut outs and the amps stayed at about 78F. I was only able to hit about -3db on the receiver before. This volume was painfully loud, so I had to take pictures quickly and get out of the room. So, it's definitely something that can be fixed with better cooling.
LFR1100 Actives,QS10HPx2,QS8x2,EP800,M3x4,M3x2 (Wood),M5HPx2 (Wood),AxiomAir,ADA1500-8,ADA1500-7
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Re: Gonna Try Building a 1kW Class D Amp for Only $396
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Joined: Dec 2008
Posts: 6,928
axiomite
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axiomite
Joined: Dec 2008
Posts: 6,928 |
That's quite a difference. Good to hear, Steve.
Half of communication is listening. You can't listen with your mouth.
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Re: Gonna Try Building a 1kW Class D Amp for Only $396
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Joined: Aug 2004
Posts: 6,379 Likes: 7
axiomite
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axiomite
Joined: Aug 2004
Posts: 6,379 Likes: 7 |
Only here (and a few other sites) would someone understand the need* to improve an amplifier so that it can play comfortably and reliably at a level which forces you to leave the room * I originally said "desire" but "need" is probably more accurate
M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39 M5HP, M40ti, Sierra-1 LFR1100 active, ADA1500-4 and -8
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Re: Gonna Try Building a 1kW Class D Amp for Only $396
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Joined: Mar 2008
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That right!
Quick question. Since I'm probably going to leave the amp unbridged, the idea popped into my head to bi-amp the M80s just to see what it sounds like.
If I remove the jumpers on the binding posts, is each pair of posts a 4 ohm load, or are they now an 8 ohm load? My guess would be 8 ohm since the jumpers acted to put the loads in parallel.
LFR1100 Actives,QS10HPx2,QS8x2,EP800,M3x4,M3x2 (Wood),M5HPx2 (Wood),AxiomAir,ADA1500-8,ADA1500-7
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Re: Gonna Try Building a 1kW Class D Amp for Only $396
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No, don't think so. Someone explained this awhile back, and they remain 4 ohm.
I am the Doctor, and THIS... is my SPOON!
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Re: Gonna Try Building a 1kW Class D Amp for Only $396
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Joined: Feb 2009
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connoisseur
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They're reactive loads due to having the crossover involved, as you get into the "cut" range of the filter it starts to act like an open circuit. So the two halves of the speaker are not in parallel.
Pioneer PDP-5020FD, Marantz SR6011 Axiom M5HP, VP160HP, QS8 Sony PS4, surround backs -Chris
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Re: Gonna Try Building a 1kW Class D Amp for Only $396
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Joined: Aug 2004
Posts: 6,379 Likes: 7
axiomite
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axiomite
Joined: Aug 2004
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Yep. The two halves of the speaker present their 4 ohm load at different frequency ranges, and have a higher impedence outside of their active ranges.
The problem is that without an electronic crossover you're sending all of the frequencies to both amps anyways, so you wouldn't get the benefits of a "real" bi-amp system that sends different frequency ranges to each amplifier.
M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39 M5HP, M40ti, Sierra-1 LFR1100 active, ADA1500-4 and -8
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Re: Gonna Try Building a 1kW Class D Amp for Only $396
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Joined: Dec 2003
Posts: 10,420
shareholder in the making
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shareholder in the making
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But you do get the advantage of full voltage power to each side, rather than having that voltage split between the upper and lower sections, not sure if that makes alot of difference to SQ, might make it even a little tighter in the bass region.
Jason M80 v2 VP160 v3 QS8 v2 PB13 Ultra Denon 3808 Samsung 85" Q70
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Re: Gonna Try Building a 1kW Class D Amp for Only $396
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Joined: Mar 2008
Posts: 1,378
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OP
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True, (and I know this was discussed many times on this board years back), but since each "half" of the speaker is only really reproducing it's frequency range and not reproducing the frequencies outside of it's range, the speaker is actually drawing less power from each amp stage at any given setting on the receiver when I bi-amp right?
What I mean is, lets say I have the receiver at -12db. The high part of the speaker is dissipating, let's say 10W, and the low part of the speaker is dissipating, let's say 10W also. That means the single amp is "delivering" 20W.
If I leave the receiver setting at -12b, and change to bi-amp, both low and high still dissipate 10W, but now each amp is only "delivering" 10W.
In the end, if I had my sound meter measuring before and after, the sound level should be the same, right? And, I gained headroom on each amp.
Am I missing something?
LFR1100 Actives,QS10HPx2,QS8x2,EP800,M3x4,M3x2 (Wood),M5HPx2 (Wood),AxiomAir,ADA1500-8,ADA1500-7
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Re: Gonna Try Building a 1kW Class D Amp for Only $396
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Joined: May 2003
Posts: 18,044
shareholder in the making
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shareholder in the making
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I think if tweeters dissipate 10W, I think they melt.
I am the Doctor, and THIS... is my SPOON!
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