Do I need bi amping?
Not likely. How exactly would that work, anyway? The class D is in the closet because it doesn't sound as good as the LM. Right? So how can removing even a part of the sound from the superior LM and giving it to the inferior D be an improvement? A better trick to try is using the D to power some subs. That for sure will be better. |
What kind of speakers again? They sound good to you now? Sure easy to do, if you want to try.. Couple cables. It amazes folks when they cut a valve amp at 60-80 hz AT LEAST, but when the passive is cut at 280-300 hz, a lot of valve amps GROW a whole new personality so to speak... A LOT of head room, they run cooler, they sound better. What else do you want? May want to check the impedance, it may change when you split the crossover.. The class d, is not going to care. The valve amp might. Just check.. Regards Regards |
If you have a "stereo" Hypex , then yes horizontal bi-amping would be great, use a $49 Schiit sys on the louder of the two amps to bring down the level, as they won't have the same gain. https://ibb.co/3SHB973 Cheers George |
Thanks for answering. My speakers are the Q Acustics Concept 500 and eventhough they are not super efficient (90 dB), the 2x48 wpc of the LM-508 drive them very well. It has dinamics, tone, layering, bass, sweetness, everything. But as always, I guess we wouldnt be audiophiles if we weren't always looking for better sound. By the way. I already have a pair of active subs with their own 500w class D amp. I think you @oldhvymec nailed it. I would like to see how the LM-508 could sound if I relieve it from handling the lower notes, like 200/300 hz and below. I guess I could also use a crossover to split the signal between the speakers and the subs (not biamping), but I guess the subs can only sound good up to 80/100 hz top, if not less. So, to really relief the valve amp and release it's full potential, I guess I have to go biamping. The big question is if it's worthwile the effort and time. So maybe hearing some other similar experiences could encourage me :-) |
If you aren't tinkering and experiencing for yourself, you are not an audiophile say I! So, you should do it for fun. Based on the impedance chart: https://www.stereophile.com/content/q-acoustics-concept-500-loudspeaker-measurements I'd say it would be interesting to compare the mid-bass performance of both amps. Why don't you try it out and tell us? |
plga OP146 posts12-09-2020 6:25amThank you George Yes many have, it’s quite simple when you look at it, all it cost is $49. If you have amp/s like you have that are good in the bass and another that’s good in the mid/highs it’s the logical way to go. Like say a Schiit 20w Class-a Aegir and a Schiit 100w Class-a/b Vidar, a perfect combo for this configuration. And what you have with the Sys, is that you can tune the sound a little, warm it up (more bass) or cool it down (less bass) Cheers George |
Yes, but maybe it's easier to use level the gain (on the XLR) with a passive preamp like this one: https://www.ebay.com/itm/253180664213 It's cheaper more adecuate as it has XLR ins and outs like I need |
that passive preamp doesn't contain a crossover; you would only be using it to equalize the the volume of the two speaker lines; you'd still be running the full bandwidth signal through both amps and through all speaker wires, not getting the benefit of crossing the signal over over at 80 hz (or even try 280-300 hz, as oldhvymec suggested above), before it gets to the LM and Hypex. You want each amp to play to its strengths and not amplify the signal frequencies it's not as good at reproducing. "biwiring" without crossing it over in front of the amps could create more problems (e.g., phase) than it would solve. |
Well yes, both amps will get full bandwidth from the preamp, but, as they will be connected to different binding posts (high and low frequencies of the speakers), wouldnt the speakers demand from them only those frequencies? I mean, if the valve amp is connected only to the speakers high frequencies binding posts, wouldnt that amp only be amplifying high frequencies? If that’s correct, wouldnt that be a relief for the that amp? |
Ok. I think I will try it that way. The only caveat is that the Concept 500 have the crossover at 2.5 khz so I will have the Class D amp runing a good part of the mid frequencies, maybe loosing some good 300B midrange smoothness. We’ll see. I think even if I had a crossover between my preamp and both amps, to split the frequencies below the speakers crossover point, I still would be limited to their 2.5 khz. So I believe there's no point on buying a specific crossover. |
I think your ok class-d to many only seems to have problems in the highs, I believe it’s because of the class-d’s output filters HF phase shift. Red trace. https://ibb.co/C16rpXx Cheers George |
Ok. I will try to see the result. But how an external active crossover will be revelatory if the internal speakers crossover is a limitation? I mean, if I only have one (1) pair of speakers, how do I biamp them using a different crossover point than the one they already have from factory? If the answer is bypasing their internal crossover, it’s outside my reach, knowledge, patience, money and will. Besides, one the best thing the Concept 500 have is their internal crossover. The blend between drivers is very very good. Another option is to use an external crossover to split the signal before the speakers, setting a crossover point between the speakers and the subs, but that would mean four things: 1- To split an amplified signal, wich I believe it’s not ideal. 2- The subwoofers shouldn’t reach more than 100 hz or their perfomance will be poor. 3- Maybe it wouldn’t be much relief for the valve amp if it only avoids amplifying the frequencies from say 100 hz and below. 4- I’ve setted up the main speakers and subs in my room considering room modes cancellation in bass frequencies. If I add an external active crossover between them, modifying their bass outputs, I may have new bass problems in the room. |
Maybe a dumb question, but I’m not an expert on the field. If I connect one amp to the high frequencies binding posts and one to the low frequencies binding posts of the speakers, and both amps are "feeding" a full range signal, I believe it won’t damage the speakers as their crossover is filtering the full range signal to what's needed for each specific driver. I mean, it will relieve the amps from amplifying the whole signal, but it won’t damage the speakers. Am I correct? |
If I connect one amp to the high frequencies binding posts and one to the low frequencies binding posts of the speakers, and both amps are "feeding" a full range signal, I believe it won’t damage the speakers as their crossover is filtering the full range signal to what's needed for each specific driver.Correct, no damage to the speaker or amp/s, and the amp will only see the load of that driver and it's xover components, less taxing for each of the amps, all better all round for everything. But you will need the $49 Sys on the louder of the two amps to make them both equal. Cheers George |
Hello OP, you have options here. BUT maybe read the END of my post first..:-) Plug the Class D into a passive preamp or the Schiit (I haven't use the Schiit). That is a high crossover point. DON'T plug your Valve amp into anything BUT the HF on board crossover of the speaker. Nothing else. They may seem to sound better/worse, be patient, let EVERYTHING settle. 2.5K and down WILL benefit from a separate tone control, The Schiit if it has an EQ that would really be nice add a little bump in the mids and volume control. That is what I do. I use a Behringer product (2496). I control everything from 300hz down with full blown DSP/Servo. 300hz UP, onboard OX of the speaker is perfect. END: Don't be surprised though, something about valves and you said it yourself. "my 2.2 system today sounds superb for me (I've heard some much more expensive ones sounding much worse)". 250 hz to 2.5K that is THE sweet spot for me, child of the 60-70s If you can live without "sugar sweet" valve doing mids.. I can for the summer months. I also can't wait for fall, right NOW...to change back to valves, though... Just sayin' Regards |
