I finished these the on the weekend. The 7Ps had been "breaking in" for a little over a month on a Trends 10.1 chip amp.
They sounded good driven by a 50w/c transistor amp and played quite loud. Then I compared them to my FF165WK MTLTs (also by B. Brines) driven by a 8w/c SET tube amp. The 6" Foxtex drivers in boxes about 10 times larger, not surprisingly, sounded much more pleasant and fuller if maybe not as precise. I knew the Alpair 7Ps, without sub-woofers couldn't compete and moved them to the smaller office.
Where they sounded fantastic! My wife was struck by the sound, stopped and listened for a while. If you're not impressed with a pair of speakers, move them to a different room. The SMSL SA-36A PRO 2* 20W TPA3118D2DAP powered by a 19v laptop adapter drives them easily. I'm thrilled with these small speakers, and so is my wife!
Thanks Bob for this design.
Cheers, Mack
An externally hosted image should be here but it was not working when we last tested it.
They sounded good driven by a 50w/c transistor amp and played quite loud. Then I compared them to my FF165WK MTLTs (also by B. Brines) driven by a 8w/c SET tube amp. The 6" Foxtex drivers in boxes about 10 times larger, not surprisingly, sounded much more pleasant and fuller if maybe not as precise. I knew the Alpair 7Ps, without sub-woofers couldn't compete and moved them to the smaller office.
An externally hosted image should be here but it was not working when we last tested it.
Where they sounded fantastic! My wife was struck by the sound, stopped and listened for a while. If you're not impressed with a pair of speakers, move them to a different room. The SMSL SA-36A PRO 2* 20W TPA3118D2DAP powered by a 19v laptop adapter drives them easily. I'm thrilled with these small speakers, and so is my wife!
Thanks Bob for this design.
Cheers, Mack
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The T7-A7 was designed for the A7.3. With minor stuffing changes it will work with the A7.2, A7P and CHN-70. I use this speaker as the tops for a 2-way with 12" sealed woofer on the bottom. DSP XO 200-300Hz range depending on the room and the day of the week.
Bob
Bob
I reckon the next box I build will be a sub for the T&-A7s. I'm thinking a T3116 2.1 would be a quick & inexpensive amp but the stereo channels run full frequency and I want to relieve them of lower freq. duties.
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Is your source going to be a PC?
Assuming you have a multi-channel sound card (most PCs do nowadays), you can also use the PC sub-woofer out; Check out the options if possible - you should be able to adjust XO frequency too.
The TPA3116D2 2.1 amps present a simple solution - not sure about XO frequency adjustment though.
Assuming you have a multi-channel sound card (most PCs do nowadays), you can also use the PC sub-woofer out; Check out the options if possible - you should be able to adjust XO frequency too.
The TPA3116D2 2.1 amps present a simple solution - not sure about XO frequency adjustment though.
I'm using Daphile on an old laptop.
Only outs are USB. It will run several DACs at once tho.
I hope there's a good 2.1 amp available. 'Would make it so easy.
Only outs are USB. It will run several DACs at once tho.
I hope there's a good 2.1 amp available. 'Would make it so easy.
The TPA3116 amps are in general very good. My personal amp is a Yaun Jing and I like it a lot. I've not seen good reviews of the 2.1 amps, primarily because the XO functionality is not good. I recommend that you get something like a miniDSP or do a line-level XO and then a separate amp for your sub(s). I have not had good luck with plate amps and do not use them.
Bob
Bob
Bob is correct, as of now, there is no TPA3116 2.1 that performs the necessary XO properly for a FAST. Your best bet is to get a second amp and do the PLLXO using low cost caps and resistors. I have been waiting for a good diyAudio implementation of a nice FAST active XO using SMT op amps and dual TPA3116 on a single board. That would really be something convenient. For reference, JBL makes a low cost monitor, the LSR305 that uses a single PCB with a class D amp similar to the 3116 (41 watts) and has built in power supply and XO for a 2-way. These speakers are self powered and go for $150 ea cabinet, drivers, amp, xo, and is flat from 43Hz to 20kHz. If one could copy that board topology and change resistors and caps to get a 300Hz XO vs 1.8kHz that would be real useful.
Thanks xrk971 for confirming. Bob's suggestion on miniDSP is a good one. I have got one, but not used it yet. Understand that it is a fairly easy to use and flexibly tool. A Y cable and couple of RCA cable sets should get you on your way. Btw, AFAIK xrk971 uses it for most of his diyAudio R&D. 🙂 And oh yes, you'll need another amp in addition to the one in the pic.
x,
Might be jumping the gun a bit as OP has not decided on miniDSP, but any guidance on how to connect one sub/helper woofer as the miniDSP is 2 in and 4 out?
x,
Might be jumping the gun a bit as OP has not decided on miniDSP, but any guidance on how to connect one sub/helper woofer as the miniDSP is 2 in and 4 out?
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Get the 2.1 plugin from miniDSP. It provides self stereo to mono summing junction for the sub and has XO with HPF for tops and LPF for sub.
2 way Advanced 21 | MiniDSP
The miniDSP is a super wonderful tool that has revolutionized my diy projects. Very easy to use and allows real-time on-the-spot changes to XO and PEQ's. Let's a newbie make a decent XO the first time around.
Can't imagine diy without it...
I wonder what the XO filter slope is and you still don't have the high pass for the full range to offload its bass duties to reduce intermodulation distortion.
While I do have one that's still operational in a upstairs system, I'm with Bob re sub "plate" amps. As I've probably mentioned before, I have a buddy who's been a car audio / speaker repair wiz at a local hi-fi shop, and one of their prime headaches is thermal failure of the amp modules in numerous commercial brands of home subs.
If you're lucky enough for them to fail while still under warranty, maybe they can get a replacement, but it's often the case that you're SOL on both counts.
While any self respecting DIY speaker builder likely has a spare amp or few that can be called into service for the HT LFE channel or other woofer applications, the XO filtering is another matter.
One piece I quite like is the Dayton APA 150 - all the flexibility you really need in a sub amp, can be run full range or even bridged to mono.
I've also had great results with one of Dayton multichannel amps for a small commercial background music system.
If you're lucky enough for them to fail while still under warranty, maybe they can get a replacement, but it's often the case that you're SOL on both counts.
While any self respecting DIY speaker builder likely has a spare amp or few that can be called into service for the HT LFE channel or other woofer applications, the XO filtering is another matter.
One piece I quite like is the Dayton APA 150 - all the flexibility you really need in a sub amp, can be run full range or even bridged to mono.
I've also had great results with one of Dayton multichannel amps for a small commercial background music system.
Well, there is another way...
HIFI Electronical 2 Way Crossover PCBA ClassA Power Linkwitz Riley filter 4 Channel Output Crossover point 2.2K Hz Free Shipping-in Other Consumer Electronics from Consumer Electronics on Aliexpress.com | Alibaba Group
The seller claims it can sell with whatever freq needed. Yes, more expensive, but right on the mark if it does that
>>> One piece I quite like is the Dayton APA 150 - all the flexibility you really need in a sub amp, can be run full range or even bridged to mono.
I have one and it's cool for its flexibility. I wasn't enamored with its grungy solid state sound compared to cheaper T-amps and more expensive tube amps... But those aren't as flexible. It's a chunky piece tho and certainly sounds as good as my 200 watt Onkyo receiver.
I have one and it's cool for its flexibility. I wasn't enamored with its grungy solid state sound compared to cheaper T-amps and more expensive tube amps... But those aren't as flexible. It's a chunky piece tho and certainly sounds as good as my 200 watt Onkyo receiver.
*Just a quick Disambiguation* Although it's probably very apparent, I share no relationship with Bob. I picked the username at random because it sounded nice. Of course Bob looks to make some very nice equipment - it would be really nice to know him!
Best
Best
Wow, that looks wonderful to my untrained eyes. If it does what it says, it's certainly worth $30.
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