It is finally time to start another speaker build, this time I hope to get what I am missing with my current speakers. My current speakers are 2-way with Morel CAW638 and Morel CAT408 in MTM setup in a vented cabinet. Not 100% sure about the crossover, got help from a friendly Canadian here on the forum many years ago.
They sound good, but they don't have the headroom, dynamics, and capability to make it feel like a live gig. At more modest levels they are great though. Now I want a 3-way build with plenty of headroom 20hz-20kHz.
Over the years I have accumulated some parts for this upcoming build. About five years ago, when I bought my house, I found a pair of unused CSS SDX12 for a good price. I think I paid around 300 euros for the pair.
I had planned on using the Beyma TPL150 and maybe the 12p80nd but they are very pricey drivers and I've heard that the TPL150 maybe isn't always as good as some people say. Especially not paired with a 12" driver. A little while ago I got a good deal on a pair of Faital Pro HF108r and STH100 horns. The horns were unused and drivers were used but not much. Paid around 40% of what they would cost new.
Now I need a driver for the midrange. Since I have the SDX12 I don't need the midrange driver to go very low. I guess crossover could be in the 100-150Hz region, or maybe even higher? I have been looking at 10" drivers for the midrange to get better high frequency capabilites and less beaming. These speakers will be used in a living room, not for live gigs or parties, so a 10" will be loud enough and I guess I should also get enough midrange punch and "feel". I have been looking at the Faital Pro 10PR410 driver. It has low mms, strong motor, and seems to play well up to ~2kHz. It is limited in bass output but the SDX12 should be able to take care of that.
For the cabinets I was thinking of building two separate cabinets stacked on top of eachother. One big box for all three drivers would be a very heavy unit and hard to move if needed. The drivers alone would weigh nearly 30kg/speaker. The SDX12 is made for small cabinets, especially when sealed, and that's what I am planning to go for. Vented would give me more bass output but it would be harder to build (long port!) and I don't think I would need that extra bass anyways. I have a relatively small living room/house and I will have DSP and plenty of amplifier power available. The 10-12" PA midrange drivers are also happy in small sealed cabinets so that is also positive. My thoughts are to build the upper mid/high cabinet with around 10-12 liters of internal volume and the same width that the SDX12 box will need. Something similar to what Jbucap here on the forum built, but of course wider than his.
Then I build the SDX12 box as narrow as possible and adjust height to get the horn in the upper box at ear level. Then I use the depth of the box to set the volume to something reasonable. I have done a little research on sealed box size and qtc and it seems like there's nothing to worry about as long as I stay below ~0.7? DSP will be used and from what I can see in WinISD a larger box will be slightly more efficient below 30Hz compared to a 30 liter box which is suggested by CSS. I will build with 22mm MDF that I bought for 90% off when a local hardware store closed a few years ago. Will of course brace properly and use double baffles for a total thickness of 44mm.
I have been thinking a lot about whether I should go with a traditional passive crossover between the mid and cd or if I should go active. With a passive crossover I can keep my MiniDSP SHD (only four output channels) and I would only need one amplifier for the mid+cd. Downside is that I have no experience designing passive crossovers and from what I understand making a digital active crossover is easier and more flexible. MiniDSP has the Flex Eight which would be perfect for an active 3-way speaker like this. With it I can experiment and adjust with different crossover settings between all three drivers and also easily adjust volume and time delay. Downside is that I would need more amplifiers.
Right now I have a pair of Emotiva UPA-1 monoblocks but I don't know if they would be suitable for this project. They have an audible humming noise in the background with my current speakers and I assume that would be maybe even worse with a high efficiency speaker like the one I'm planning to build. Class D amplifiers have gotten better and cheaper and the Topping PA5 for example is praised for its sound and "silence" but it also has increased distortion in the higher frequencies so maybe it's only suitable for the midrange and not for the compression driver? What amplifier should I look for with the compression driver? For the subs I just purchased a used Behringer NX6000D for a very good price so that is sorted already.
I realise this is pretty much a 2-way speaker with a subwoofer used as a stand, but it's a 3-way system so I don't really know I should call it, hence the title of this thread.
Do you have any other recommendations for midrange drivers? Any recommendations for crossover frequencies to begin experimenting with?
They sound good, but they don't have the headroom, dynamics, and capability to make it feel like a live gig. At more modest levels they are great though. Now I want a 3-way build with plenty of headroom 20hz-20kHz.
Over the years I have accumulated some parts for this upcoming build. About five years ago, when I bought my house, I found a pair of unused CSS SDX12 for a good price. I think I paid around 300 euros for the pair.
I had planned on using the Beyma TPL150 and maybe the 12p80nd but they are very pricey drivers and I've heard that the TPL150 maybe isn't always as good as some people say. Especially not paired with a 12" driver. A little while ago I got a good deal on a pair of Faital Pro HF108r and STH100 horns. The horns were unused and drivers were used but not much. Paid around 40% of what they would cost new.
Now I need a driver for the midrange. Since I have the SDX12 I don't need the midrange driver to go very low. I guess crossover could be in the 100-150Hz region, or maybe even higher? I have been looking at 10" drivers for the midrange to get better high frequency capabilites and less beaming. These speakers will be used in a living room, not for live gigs or parties, so a 10" will be loud enough and I guess I should also get enough midrange punch and "feel". I have been looking at the Faital Pro 10PR410 driver. It has low mms, strong motor, and seems to play well up to ~2kHz. It is limited in bass output but the SDX12 should be able to take care of that.
For the cabinets I was thinking of building two separate cabinets stacked on top of eachother. One big box for all three drivers would be a very heavy unit and hard to move if needed. The drivers alone would weigh nearly 30kg/speaker. The SDX12 is made for small cabinets, especially when sealed, and that's what I am planning to go for. Vented would give me more bass output but it would be harder to build (long port!) and I don't think I would need that extra bass anyways. I have a relatively small living room/house and I will have DSP and plenty of amplifier power available. The 10-12" PA midrange drivers are also happy in small sealed cabinets so that is also positive. My thoughts are to build the upper mid/high cabinet with around 10-12 liters of internal volume and the same width that the SDX12 box will need. Something similar to what Jbucap here on the forum built, but of course wider than his.
Then I build the SDX12 box as narrow as possible and adjust height to get the horn in the upper box at ear level. Then I use the depth of the box to set the volume to something reasonable. I have done a little research on sealed box size and qtc and it seems like there's nothing to worry about as long as I stay below ~0.7? DSP will be used and from what I can see in WinISD a larger box will be slightly more efficient below 30Hz compared to a 30 liter box which is suggested by CSS. I will build with 22mm MDF that I bought for 90% off when a local hardware store closed a few years ago. Will of course brace properly and use double baffles for a total thickness of 44mm.
I have been thinking a lot about whether I should go with a traditional passive crossover between the mid and cd or if I should go active. With a passive crossover I can keep my MiniDSP SHD (only four output channels) and I would only need one amplifier for the mid+cd. Downside is that I have no experience designing passive crossovers and from what I understand making a digital active crossover is easier and more flexible. MiniDSP has the Flex Eight which would be perfect for an active 3-way speaker like this. With it I can experiment and adjust with different crossover settings between all three drivers and also easily adjust volume and time delay. Downside is that I would need more amplifiers.
Right now I have a pair of Emotiva UPA-1 monoblocks but I don't know if they would be suitable for this project. They have an audible humming noise in the background with my current speakers and I assume that would be maybe even worse with a high efficiency speaker like the one I'm planning to build. Class D amplifiers have gotten better and cheaper and the Topping PA5 for example is praised for its sound and "silence" but it also has increased distortion in the higher frequencies so maybe it's only suitable for the midrange and not for the compression driver? What amplifier should I look for with the compression driver? For the subs I just purchased a used Behringer NX6000D for a very good price so that is sorted already.
I realise this is pretty much a 2-way speaker with a subwoofer used as a stand, but it's a 3-way system so I don't really know I should call it, hence the title of this thread.
Do you have any other recommendations for midrange drivers? Any recommendations for crossover frequencies to begin experimenting with?
At Parts Express' most recent SDC meet back in August, there was a person who dealt with noise in his horns by using a Powersoft amp, as it was dead silent. I know those are salty. My passed friend swore by analog xovers, as they had less noise than the Driverack Pro he was using prior. I've seen a few people use the old Overture Class AB chips because their background is silent.
There unfortunately are many rabbit holes to go down in terms of solutions for lowering the noise floor in your horns. Good luck finding one that suits you.
There unfortunately are many rabbit holes to go down in terms of solutions for lowering the noise floor in your horns. Good luck finding one that suits you.
I have read several reviews at Audio Science Review forums and it seems like the modern class D amps perform well in that regard, such as the Topping PA 5 II. AmirM says "My target for 5 watts is 96 dB or 16 bits and the PA5 II sails way past that. At full power, it reaches provably inaudible noise level even with very sensitive speakers.". It delivers 53 watts at 8 ohm which is way more than I will ever need, at least for the horn. The downside is increased distortion at higher frequencies, especially above ~5kHz and at loads over 3 watts. However I don't think I'll use more than 3 watts very often, considering the HF108r is 109dB/1w.
A simple way to ensure residual amplifier noise remains inaudible with a 110 dB/W horn is to choose an amp with low noise and modest/low gain. You certainly won't need the gain or power anyway with such a horn at home.
Edit: That Topping PA5 II is spec,'d at 19.2 dB gain, which is probably 8-10 dB lower than many consumer amps, so it's a good candidate.
If you are still bothered by noise, make an L-pad with quality resistors.
Edit: That Topping PA5 II is spec,'d at 19.2 dB gain, which is probably 8-10 dB lower than many consumer amps, so it's a good candidate.
If you are still bothered by noise, make an L-pad with quality resistors.
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Maybe just go active and begin learning dsp filters. Hypex plate amp or similar.
Your speakers look good
Your speakers look good
Btw, amirm's comments about the PA5 II distortion at higher frequency distortion is only relative to that at lower frequencies. It looks very low distortion overall.
Ok seeAlso, I have to say that having tried 110dB/W compression horns with a super quiet Hypex nc252 amp (25 dB gain), I could still hear residual hiss from 1 meter or less. It only became completely inaudible when I added an L-pad.
Ok seeAlso, I have to say that having tried 110dB/W compression horns with a super quiet Hypex nc252 amp (25 dB gain), I could still hear residual hiss from 1 meter or less. It only became completely inaudible when I added an L-pad.
I compared the distortion specs of the PA5 II compared to some other well regarded amplifiers and as you say, overall it is pretty low distortion so I guess it wont be an issue for me.
I have zero experience with L-pads. From what I can understand they are like a potentiometer that "soaks up" some of the power from the amplifier, reducing the power going to the driver and effectively reducing the sensitivity of the speaker but still maintaining the same impedance as if the L-pad was never there?
I have zero experience with L-pads. From what I can understand they are like a potentiometer that "soaks up" some of the power from the amplifier, reducing the power going to the driver and effectively reducing the sensitivity of the speaker but still maintaining the same impedance as if the L-pad was never there?
I think you should look into some 8" midbasses too. 10" being how you will use it really isn't required as you won't need to go low. B&C makes some very good 8" and 10" drivers that should not be left out of the running, especially their neo models. Power response and directivity will likely be easier to align with an 8" model.
I have been thinking about 8" too but as the saying goes, there's no replacement for displacement. I want dynamics and "impact" in the midrange and I'm not sure if an 8" will do that. An 8" will have less cone area than my current two 6.5". Sure, an 8" PA midrange will have higher sensitivity but I still think a 10" will suit me better. I understand that a 10" will have more beaming and worse high frequency response, but since I wont be using these speakers in a PA setting I should be able to cross the CD slightly lower than what is normally done in a PA speaker.