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DIY audio: what are you building?


Paul Spencer

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On 11/11/2020 at 11:48 PM, oohms said:

 

Sad to hear about the waveguides being discontinued, I only got these a couple of months ago

I am running passive at the moment but have run them active before. This is the current prototype xo:

IMG_20201111_234508.thumb.jpg.2b5f54318b566c84147bbeb023d5a658.jpg

 

IMG_20201111_234528.thumb.jpg.831e6329d52dbeff24bec37a015004c9.jpg

 

 

I'm itching to make something similar. 

I'm really bummed about the waveguide being discontinued.

 

Have you tried pairing both 1.4inch compression V's 1inch with the 15pr400?  

It would be my assumption a 1.4inch would work better? 

I.e. HF108r v's HF146? 

 

The HF201 looks great to:

https://faitalpro.com/en/products/HF_Drivers/product_details/index.php?id=502030155

 

The new SB acoustic compression drivers also look great value:

https://www.wagneronline.com.au/sb-audience-1-compression-driver-50w/sb-audience-range/sb-acoustics/speaker-drivers/audio-speakers-pa/bianco-44cd-pk-89862/1002195/pd/

 

Honestly, I'm stuck in decision phase.

15pr400 V's 12pr300 with dual subs. 

 

I suspect with a bit of PEQ I would be happy with the 15pr400's bass response. 

 

I recently acquired a Firstwatt F7, which I was hoping to run on the compression horn (I suspect this will sound magic).

I was then thinking a decent class AB @ 12-14db gain for the woofer. maybe even a 1ET400a purifi in gain free mode. 

 

I sit near field, so I need a hiss/noise free system. 

The Firstwatt F7 is absolutely noise/hiss free in passive mode, running some three ways atm. 

 

I am yet to find a DSP I can say the same about. 

Any pointers/advice would be great.  

  

 

 

 

Edited by Grizaudio
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The 1 inch vs 1.4 inch compression driver is a tradeoff between crossover frequency and treble extension.  Some 1.4"/2" drivers have good treble, the HF144/146 are supposed to be amongst them, but at the same time you need a larger horn to cross lower

 

The 15PR400 can play fine up to 4khz, which we tested at an audio night by sweeping the crossover to large horn mids between 400hz and 4khz and the sound signature remained the same. The directivity does start narrowing earlier for the larger 15 inch driver, so I wanted to cross it to the 1" horn as close to 1khz as possible for it to match the directivity of the QSC waveguide

 

Regarding the woofer choice, if you are ok with large cabinets (say 180-220 liters) then the 15PR400 will go down to 35hz or so, and mine go down to 30, but they are also in the corners of the room

 

For use with valve amps, the 15PR400 in large cabs and passive crossovers will let you do that, with minimal external gear.

 

Check out the Calpamos, if you want something that has already been designed and built

http://www.humblehomemadehifi.com/download/Humble Homemade Hifi_Calpamos.pdf

Edited by oohms
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6 minutes ago, oohms said:

The 1 inch vs 1.4 inch compression driver is a tradeoff between crossover frequency and treble extension.  Some 1.4"/2" drivers have good treble, the HF144/146 are supposed to be amongst them, but at the same time you need a larger horn to cross lower

 

The 15PR400 can play fine up to 4khz, which we tested at an audio night by sweeping the crossover to large horn mids between 400hz and 4khz and the sound signature remained the same. The directivity does start narrowing earlier for the larger 15 inch driver, so I wanted to cross it to the 1" horn as close to 1khz as possible for it to match the directivity of the QSC waveguide

 

Regarding the woofer choice, if you are ok with large cabinets (say 180-220 liters) then the 15PR400 will go down to 35hz or so, and mine go down to 30, but they are also in the corners of the room

 

For use with valve amps, the 15PR400 in large cabs and passive crossovers will let you do that, with minimal external gear.

 

Check out the Calpamos, if you want something that has already been designed and built

http://www.humblehomemadehifi.com/download/Humble Homemade Hifi_Calpamos.pdf

 

Thanks for the reply. Appreciate the link. I have read that one. Hence my HF201 suggestion. 

 

Its good to know your having a positive time with the 15pr400, and HF108r pairing.

I think the best way forward is to simply make a choice and jump in. Its a journey after all. ;) 

 

FYI.... A few articles I have read, demonstrate the HF108r to have significant distortion around 1khz. Indicating it would be better suited at a 12-8inch woofer pairing. Which is why I was curious about the pairing. 

 

Looking at its distortion charts, distortion exponentially increases below 1200-1300khz to what are audible levels/%'s.

 

@1khz the HF108r gets up around 5%-6% distortion. Which is quite high. 

 

I am looking for a low distortion design, so will probably stick with a 1.4inch-2 inch compression driver, loaded in a horn to 800hz or so (Subject to directivity matching). 

I'll look to correct frequency response with DSP. 

 

https://audioxpress.com/article/test-bench-faital-pro-hf108r-compression-driver

image.thumb.png.c67990b68ea61f4343aae41198b80a3c.png

 

 

 

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10 minutes ago, Grizaudio said:

 

FYI.... A few articles I have read, demonstrate the HF108r to have significant distortion around 1khz. Indicating it would be better suited at a 12-8inch woofer pairing. Which is why I was curious about the pairing. 

 

Looking at its distortion charts, distortion exponentially increases below 1200-1300khz to what are audible levels/%'s.

 

 

Yep, probably from its 1khz resonance peak.. that's why i ordered the peerless drivers, they should be here in a couple of days


Additionally i was exploring the option of a midrange horn somewhere along the lines of Wayne Parnham's one that he uses with the Pi corner horns

Initially i ran massive horns on top from 300hz and up, but the treble was compromised

 

So depending on the results with the peerless driver, I'll either keep it a 2 way or make it a 3 way if all else fails

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Very impressive indeed. 

 

The Tymphany look like great drivers. 

Lots of positive reviews.... I guess on the right waveguide, they would sound great.

 

image.thumb.png.d70e158fa014bc8dd581eeb1d60b21a3.png

 

Response is similar to the Celestion:

The Celestion seems to have a pretty constant impedance.

image.thumb.png.8688d614895ced36b22cc3ba1b642103.png

https://celestion.com/product/53/cdx11445/

 

Another option if the Faital 10ak, although better suited for 8-10inch drivers by user accounts. 

https://faitalpro.com/en/products/HF_Drivers/product_details/index.php?id=502010110

image.thumb.png.9876f5648b5f9f22bbb05fe308a379b9.png

Edited by Grizaudio
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I never found out how to connect up that SC Pre I was given as a gift from one mate, so I gifted it to another mate who is very knowledgeable and he has made a nice job of it.

 

SC1.jpeg.992e6a528aadbd3676fb17278e8613e6.jpeg

 

Sitting atop his Minimax.

1355101131_SCandMinimax.jpeg.1d5e7aacf38becedc3b071562a00c28f.jpeg

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8 minutes ago, muon* said:

I never found out how to connect up that SC Pre I was given as a gift from one mate, so I gifted it to another mate who is very knowledgeable and he has made a nice job of it.

 

SC1.jpeg.992e6a528aadbd3676fb17278e8613e6.jpeg

 

Sitting atop his Minimax.

1355101131_SCandMinimax.jpeg.1d5e7aacf38becedc3b071562a00c28f.jpeg

The LDR feeds his build using T3 modules.

1772492520_T3amp.jpeg.0a0b9425de776e0f65be1d31c9b7d083.jpeg

 

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What started with a hum and buz is now playing clean and mean. Firstly the mains earth and signal earth were joined. Removing the mains earth from the signal earth got rid of the hum. My speakers are 90db efficient and any noise is heard. The whole chassis is earthed and fused. 
 

Moved some wiring near the pot around got rid of the buz. The big surprise was the the Con organ 12AU7 was chronically microphonic. You couldn’t even lightly tap the enclosure without producing a thump. Turning the amp off, which immediately disconnects the speakers (crowbar speaker protection on the T4 board ensures this), would produce a thump. 
 

Replacing the tube with a newish Raytheon tube and Teflon tube damper fixed this 100%. I have to tap hard on the tube to get any noise at all through the amp. Not only that the Raytheon is a hell of a lot clearer. Dearer but much better.

 

Now off to the new owner tomorrow. I’m missing it already. 

945D2C7B-1B12-427A-9FBC-9CD67C23C014.jpeg

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I sold mine. I found it’s implementation had a high noise floor. Tube microphonics etc. 

 

I much prefer my RME ADI in my current system. My Firstwatt f7 adds nice smoothness and tone to the sound. 
 

I might be looking to a motu8 or okto dac8 yet, as I look to go active with roon. 
 

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Here are a few new images of “Succinct-II” also my blog posting. Still sorting a few things out with the amp but I’m extremely pleased with the sound. If I didn’t have my DIY 300W Holton this amp wouldn’t be going anywhere. In the flesh it looks quite compact and even sexy. 
 

http://retro-thermionic.blogspot.com/2020/11/succinct-ii-integrated-180w-class-d-amp.html

 

6EEC74A1-ACD7-4281-898D-C8D7B0FD2111.jpeg

6355A44F-A620-4734-9499-61E669C79C87.jpeg

2BBC50C8-8952-4F4B-8D16-C5F022209122.jpeg

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1 hour ago, mwhouston said:

Here are a few new images of “Succinct-II” also my blog posting. Still sorting a few things out with the amp but I’m extremely pleased with the sound. If I didn’t have my DIY 300W Holton this amp wouldn’t be going anywhere. In the flesh it looks quite compact and even sexy. 
 

http://retro-thermionic.blogspot.com/2020/11/succinct-ii-integrated-180w-class-d-amp.html

 

6EEC74A1-ACD7-4281-898D-C8D7B0FD2111.jpeg

6355A44F-A620-4734-9499-61E669C79C87.jpeg

2BBC50C8-8952-4F4B-8D16-C5F022209122.jpeg

Very clean look front panel appearance with all the trick Tube/D class work hidden.

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2 hours ago, mwhouston said:

Here are a few new images of “Succinct-II” also my blog posting. Still sorting a few things out with the amp but I’m extremely pleased with the sound. If I didn’t have my DIY 300W Holton this amp wouldn’t be going anywhere. In the flesh it looks quite compact and even sexy. 
 

 

6355A44F-A620-4734-9499-61E669C79C87.jpeg

 

 

Nice-looking case, Mark.  :thumb:

 

Where do you get them from ... and do they have different sizes?

 

Andy

 

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On 08/11/2020 at 12:08 PM, mwhouston said:

Another mono Salt Cellar setup.

C42F85FB-6765-4E5A-9FBC-731079A102CA.jpeg

98072457-3122-4D22-BE3F-B533115D64B4.jpeg

 

I'm curious.

 

What's your favourite full range bass driver and horn combo that's currently commercially available? 

I.e. 15inch and compression/waveguide. 

 

 

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11 minutes ago, Grizaudio said:

 

I'm curious.

 

What's your favourite full range bass driver and horn combo that's currently commercially available? 

I.e. 15inch and compression/waveguide. 

 

 

I’d go for these.

 

https://faitalpro.com/en/products/LF_Loudspeakers/product_details/index.php?id=101060100

 

https://faitalpro.com/en/products/HF_Drivers/product_details/index.php?id=502010110
 

https://faitalpro.com/en/products/HF_Horns/product_details/index.php?id=903010110

 

Very high efficiency and goes very low. Great for SETs.

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59 minutes ago, Grizaudio said:

 

I'm curious.

 

What's your favourite full range bass driver and horn combo that's currently commercially available? 

I.e. 15inch and compression/waveguide. 

 

 

 

43 minutes ago, mwhouston said:

Might be a dumb question , but no mid-range required with those choices? Is the horn driver covering everything above the base driver?

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25 minutes ago, Compass said:

 

Might be a dumb question , but no mid-range required with those choices? Is the horn driver covering everything above the base driver?

Strange as it might seem to those used to hifi speakers, this type of 12-15 inch pro woofer are more midrange than bass drivers. The tweeter/horn combo will crossover at about 1-1.5kHz to the 15 incher which will extend down to 40-100Hz depending on the enclosure.  You will then need a dedicated bass driver or separate subwoofer to get full range output.

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23 minutes ago, RoHo said:

Strange as it might seem to those used to hifi speakers, this type of 12-15 inch pro woofer are more midrange than bass drivers. The tweeter/horn combo will crossover at about 1-1.5kHz to the 15 incher which will extend down to 40-100Hz depending on the enclosure.  You will then need a dedicated bass driver or separate subwoofer to get full range output.

The reason why I selected this woofer is that it will go low and extend to 1100hz where I would Xover to the horn. 

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Given what Matty says about his LDR Pre, and my other friends experience with the SC, I'm looking at a ePot Mini with the LDR Module from Tortuga Audio to replace the Comos pot in my EL34 amp.

 

https://tortugaaudio.com/products/diy-preamp-components/electronic-stepped-attenuator-epot-v3-mini/

 

I'll run it without display as my needs are basic, one source is all I need and the ePot mini will have the remote for the basic functions I required.

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