Might be the wrong time of year to be thinking about a speedy delivery.
Hope you've got something good to drink while you're waiting..... Merry Christmas and all the best in the new year,
Chris M
Hi Henderson,
Yea, you are correct in that not much more in the way of drivers would be required. I had not really thought of going that route as of now but it could be expanded to something like you mentioned in the future. I'm not sure if I will build anymore speakers after this pair. I don't have rooms available for those built thus far. So, to keep this fun hobby going, I will put my efforts into tweaking the ones I have built to make them better where needed.
Best Regards,
Rich
Yea, you are correct in that not much more in the way of drivers would be required. I had not really thought of going that route as of now but it could be expanded to something like you mentioned in the future. I'm not sure if I will build anymore speakers after this pair. I don't have rooms available for those built thus far.
So, to keep this fun hobby going, I will put my efforts into tweaking the ones I have built to make them better where needed.Best Regards,
Rich
Yet another suggestion: You could do something in the middle, a 2" FR like the Visaton FRS 5 X, which is very cheap and sounds very good, also very linear. Crossed over at ~1000Hz could work with the Peerless. I'm not sure, the spl of the Visaton is maybe just enough because you'll lose a few dB of the 8" anyway unless you're aiming for a wide enclosure. If the FRS 5 X isn't loud enough just view it as a suggestion for similar 50-65mm FR drivers.
What do you see that makes you think it has to be crossed at 2kHz?
These tests make it seem like it'd be OK lower than that. I was thinking about getting some of these because it looks good in these 3rd party tests + is one of the (relatively few) tweeters I can get locally for a good price.
Test Bench: Scan-Speak Discovery D2604/833000 1″ Wide Surround Silk Dome Tweeter
Test Scan-Speak Discovery D2604 / 833000 mit WG PCT-300 / WG-300 – Heissmann Acoustics
YW
Another very interesting speaker is the Tang Band 25-2234S, inverse aluminium/magnesium dome, very small in size, 48mm square. It was tested in the German magazine Hobby Hifi 6/2017 with very good measurements, can be crossed over at 1,5 kHz or even 1kHz if you accept a tad delayed decay below 1,5kHz. Also inexpensive, 28€ over here.
The Scan Speak got a bit better linearity, the TB reaches 40k with still ~86dB.
I've seen several tests and the highest crossing over recommendation which was supported by measurements was at 1,5kHz, others speak of 1000Hz. I personally wouldn't go lower than 1,5kHz for the SS or the TB.
1) The D2604/833000 SPL@2.83V drops 3db between 2kHz and 1kHz. The SB29RDC SPL@2.83V gains +1db between 2kHz and 1kHz.
2) D2604/833000 Sd = 8.00 cm2. SB29RDC Sd = 9.6 cm2.
3) The SB29RDC is known for excellent low F3 crossovers.
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The Visaton FRS 5X has a rated power of just 5-Watts, and a sensitivity of 84db at 700Hz
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montana1: Attached example baffle diffraction effects for a W=12", H=18" cabinet, which offers ~1cuft with D=12". Note the dome is offset 0.8" to spread edge diffraction, and edges have 0.5" radius. Once you decide upon a "clever" cabinet shape, the CAD tools can equalize the vendor frequency and impedance data for an early crossover paper design to avoid major mistakes before any build + measure + "finally" buy
2) D2604/833000 Sd = 8.00 cm2. SB29RDC Sd = 9.6 cm2.
3) The SB29RDC is known for excellent low F3 crossovers.
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The Visaton FRS 5X has a rated power of just 5-Watts, and a sensitivity of 84db at 700Hz
=======
montana1: Attached example baffle diffraction effects for a W=12", H=18" cabinet, which offers ~1cuft with D=12". Note the dome is offset 0.8" to spread edge diffraction, and edges have 0.5" radius. Once you decide upon a "clever" cabinet shape, the CAD tools can equalize the vendor frequency and impedance data for an early crossover paper design to avoid major mistakes before any build + measure + "finally" buy
Attachments
Depending on the enclosure and its dimensions (baffle-step) and the crossover, you'll lose 3-4dB, sometimes more. 89-4=85dB. It's probably tight but within reach. And you surely read that I did not recommend crossing it over at 700Hz, did you?
5W is low, yes. That's rms though, music and peak power can be much higher and the 5W are the full range rated power. If you cross it over higher than full range, the power rating goes up. Midrange speakers with similar voice coil sizes are usually rated 20-40W rms. What's okay for you depends on how loud they have to play, speakers with the FRS 5 X have proven to have no problems with 95 dB or even more. Maybe look i.e. at the CT285 of the german magazine Klang+Ton. That is the FAST version (they got also 2 others wich are crossed over higher), it's crossed over at just 400Hz and they still get only a maximum 1,5% distortion from 300Hz on up at 95dB. That means, over the complete range of the FRS 5 X. And it also means, there's still room. Did I mention that I did not recommend crossing it over at 700Hz, instead 1000Hz? There you get your headroom.
Remember: If you are comparing specs, be careful how they are measured and if that applies to the use you're planning. The common lies are power, Xmax (read exactly how they come up with these numbers and if it's not a lot less instead of more if you calculate it the same way) and frequency response diagrams. Most ratings will drop, some can actually rise, depending on what you're doing.
ICG,
Everything you mentioned makes perfect sense. Thanks for sharing that information! I'm leaning towards going the SB Acoustics 29RDC route LineSource suggested. I've heard nothing but compliments regarding this tweeter and most of their product line. This seems like a good opportunity to give them a go.
Best Regards,
Rich
Everything you mentioned makes perfect sense. Thanks for sharing that information! I'm leaning towards going the SB Acoustics 29RDC route LineSource suggested. I've heard nothing but compliments regarding this tweeter and most of their product line. This seems like a good opportunity to give them a go.
Best Regards,
Rich
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Hi LineSource,
Thanks once again for taking the time to share your thoughts on this build! I'm very interested in purchasing the SB tweeters you suggested. I just have a few questions:
1) Does the SB tweeter require a waveguide to cross at 1.4 khz?
2) Can tweeter be mounted below woofer with good results? (I attached cab pic to see progress thus far)
3) Could you explain how to import frequency and imp data into Baffle Diffraction simulator?
4) Would you mind sharing your work flow for simulations?
Dimensions of cabinet in photo is Height=25", Width=12", and depth=15". Net internal volume is 40 liters approx.
Best Regards,
Rich
Thanks once again for taking the time to share your thoughts on this build! I'm very interested in purchasing the SB tweeters you suggested. I just have a few questions:
1) Does the SB tweeter require a waveguide to cross at 1.4 khz?
2) Can tweeter be mounted below woofer with good results? (I attached cab pic to see progress thus far)
3) Could you explain how to import frequency and imp data into Baffle Diffraction simulator?
4) Would you mind sharing your work flow for simulations?
Dimensions of cabinet in photo is Height=25", Width=12", and depth=15". Net internal volume is 40 liters approx.
Best Regards,
Rich
Attachments
700Hz is stuck in my brain..... sorry for the side-track
Dr. Griesinger's research demonstrated that 700-7000Hz is the critical range of frequencies where our hearing and our brain combine the fundamental sound with its harmonics. According to Griesinger, we detect pitch more on the higher harmonics than we do on the fundamental. One of the main benefits of adding a small diameter full range is to cover the critical 700-7000Hz, and then accept the best extension near 20kHz as possible. A 700Hz crossover also removes beaming and cone grunge from the Peerless.
700Hz is ofcourse a mark of importance, no doubt about that. Dynamics is not any less important and for higher power the crossover frequency really helps a lot. Nonetheless, the K+T project was at a xo of 400 Hz and it seems to work well.
@montana1:
1) No. But it helps a lot dynamics wise.
2) That depends. The goal is to keep the tweeter around ear height. If you get too low, the stage collapses and it sounds completely flat. Besides that, even in a WG floor reflections are still an issue, the lower, the worse.
@montana1:
1) No. But it helps a lot dynamics wise.
2) That depends. The goal is to keep the tweeter around ear height. If you get too low, the stage collapses and it sounds completely flat. Besides that, even in a WG floor reflections are still an issue, the lower, the worse.
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