Reducing the volume of the back chamber (a BLH doesn't have a compression chamber other than the room) will increase the upper corner frequency of the horn (i.e. it'll run up higher).
Word of warning about changing the throat area: stage expansion designs do not work in the same way as constant expansion so changing this will cause problems unless you can redesign the rest of the cabinet while you're at it.
Lining the chamber & down the first path to the rear should be sufficient to handle any reflections & damp out possible standing waves.
Word of warning about changing the throat area: stage expansion designs do not work in the same way as constant expansion so changing this will cause problems unless you can redesign the rest of the cabinet while you're at it.
Lining the chamber & down the first path to the rear should be sufficient to handle any reflections & damp out possible standing waves.
Both tweaks take very little time and are completely reversible.
Perhaps the 206ESR benefits from this upper corner frequency run up as we (my friend and I) still prefer it? Every room and system is different though, so it might not be for everyone. Just reporting more tweaks that can be played around with for those who are asking for tuning advice.
Perhaps the 206ESR benefits from this upper corner frequency run up as we (my friend and I) still prefer it? Every room and system is different though, so it might not be for everyone. Just reporting more tweaks that can be played around with for those who are asking for tuning advice.
Mahogany veneered Sachiko
Finished these about three weeks ago. Maple ply with mahogany veneer. Polycrylic over veneer. Non-veneered wood is painted black using General Finishes Lamp Black milk paint.
So far I've built two pairs of Saburo's and two pair of Sachiko's. One pair of Saburo's I used Canadian Maple ply, the other Imported Cherry Ply. One Sachiko was built with Birch and the other Maple. It has been interesting hearing the differences between wood species used in each of the builds.
Finished these about three weeks ago. Maple ply with mahogany veneer. Polycrylic over veneer. Non-veneered wood is painted black using General Finishes Lamp Black milk paint.
So far I've built two pairs of Saburo's and two pair of Sachiko's. One pair of Saburo's I used Canadian Maple ply, the other Imported Cherry Ply. One Sachiko was built with Birch and the other Maple. It has been interesting hearing the differences between wood species used in each of the builds.
Attachments
Possible as it's got a bit of a dip in its FR around fhm. That said, you generally need to be careful running the enclosure up that high as you don't want the outputs to comb -the MTM layout helps a bit, but still something to be aware of.
Thanks for that guys.I'm just trying to avoid having clamps on them for the next year.I'm still trying to learn all of this and am still quite lost.
For now I'm breaking them in a pair of old Marantz BR and sound very good with a Fisher 500-c.I wasn't expecting much bass but it's there and powerful.Just a tad bright though.
Doug
For now I'm breaking them in a pair of old Marantz BR and sound very good with a Fisher 500-c.I wasn't expecting much bass but it's there and powerful.Just a tad bright though.
Doug
Re: Mahogany veneered Sachiko
what, no MDF?
seriously, tho - care to attempt subjective descriptions of the sonic differences between the materials?
don't be afraid to use colours, flavors, or any other analogies
and remind us of what amp(s) you're using?
cervelorider said:
what, no MDF?
seriously, tho - care to attempt subjective descriptions of the sonic differences between the materials?
don't be afraid to use colours, flavors, or any other analogies
and remind us of what amp(s) you're using?
Wood
In short, the Maple seems more "lively" sounding than both the Birch and the Cherry, in both the Saburo and Sachiko designs. The Cherry, and to a lesser extent, the birch, seemed to exhibit a bit more weight, without sounding dull. By no means is one "better" than the other. It boils down to what flavor one prefers.
As for my system in which all four have resided at one time or another:
Jolida 300B amp, Decware Zen with EX mod, Rawson Gainclones
(one integrated and another standalone with a Grounded Grid tube preamp & passive pre currently)
Rega Apollo CDP
Garrard 95B table and Plinius Jarrah phono preamp.
Copper DIY speaker cables and interconnects.
In short, the Maple seems more "lively" sounding than both the Birch and the Cherry, in both the Saburo and Sachiko designs. The Cherry, and to a lesser extent, the birch, seemed to exhibit a bit more weight, without sounding dull. By no means is one "better" than the other. It boils down to what flavor one prefers.
As for my system in which all four have resided at one time or another:
Jolida 300B amp, Decware Zen with EX mod, Rawson Gainclones
(one integrated and another standalone with a Grounded Grid tube preamp & passive pre currently)
Rega Apollo CDP
Garrard 95B table and Plinius Jarrah phono preamp.
Copper DIY speaker cables and interconnects.
peterr said:
Thanks I will pay carrefull attention (i don't know if it's the rigth expresion) to your work and will have probably some more questions.
Marc
I'm going to add a BSC circuit to my pair of sachikos. Looking at the 206E data sheet, I use the Re value of 6.69ohms for the calculation correct? With a baffle width of 13 inches and 6db attenuation I get an f3 of 350.8hz Lbsc of 3 milli henries and Rbsc of 6.7 ohms. Does this sound correct? Thanks.
Well, the design is actually a 13.25in baffle so 4560 / 13.25 = an F3 of 344Hz, which is close enough.
However, the point I'm most curious about is exactly why on Earth do you want to add a passive circuit to a horn? Especially something as extreme as 6db! Granted, an MLTL or BR will need something like that, as they aren't especially directional and have a very narrow operational BW. But a horn like Sachiko is an intrinsically high-gain device (which is the entire point), with a broader operating BW. Some of that gain is used in actively countering step-loss, and that's before their increased directionality is considered. Sachiko should be producing from 95 - 100db 1w down to ~40Hz in-room; step loss shouldn't even be a consideration. What is it you're actually trying to achieve?
However, the point I'm most curious about is exactly why on Earth do you want to add a passive circuit to a horn? Especially something as extreme as 6db! Granted, an MLTL or BR will need something like that, as they aren't especially directional and have a very narrow operational BW. But a horn like Sachiko is an intrinsically high-gain device (which is the entire point), with a broader operating BW. Some of that gain is used in actively countering step-loss, and that's before their increased directionality is considered. Sachiko should be producing from 95 - 100db 1w down to ~40Hz in-room; step loss shouldn't even be a consideration. What is it you're actually trying to achieve?
Oh really? For some reason I thought people were running those correction circuits on the Fostex drivers in general to kill some of the shout. I guess I jumped the gun a little without reading into it enough.
A BSC circuit is used to attenuate frequencies above the step loss point to rebalance the overall response trend. That assumes that step loss is an issue & not already being countered by something else (such as cab. gain).
There are other types of similar Eq circuit -notch filters etc., which handle narrow band response issues inherent to the driver itself. The 206, like many FR drivers, especially those with a high Bl factor, has an upwardly tilting response trend in IB conditions; however, the air-mass in the horn will damp this to an extent & to the best of my knowlege is one of the reasons such drivers are favoured as they are a little less likely to suffer HF losses. Still limp compared to a compression unit of course.
If you haven't got phase plugs in your 206s, now is the time. It sounds very much to me like your issue is one they will solve.
There are other types of similar Eq circuit -notch filters etc., which handle narrow band response issues inherent to the driver itself. The 206, like many FR drivers, especially those with a high Bl factor, has an upwardly tilting response trend in IB conditions; however, the air-mass in the horn will damp this to an extent & to the best of my knowlege is one of the reasons such drivers are favoured as they are a little less likely to suffer HF losses. Still limp compared to a compression unit of course.
If you haven't got phase plugs in your 206s, now is the time. It sounds very much to me like your issue is one they will solve.
Scottmoose said:
Although not the same driver or enclosure design, I recently installed a pair of phase plugs in FE167E (EnABLed) mounted in Demetris. They certainly helped with clarity, focus and soundstage depth - most notably in the midrange. It does require that leap of faith and a steady hand with the scalpel, but well worth it IMHO.
As Scott said, there are many ways to deal with the "demon" of baffle step loss in single driver/full range systems: wide baffles, Suprabaffles (a la Ron Clark's A126 / Frugelhorn / Aiko ) corner placement, bipole etc.
Regarding correction via passive EQ networks, I'd suggest one needs to be careful aggressively pursuing "smooth" looking graphs.
The combinations of some corrections circuits I've seen must have as much complex reactance as many crossover networks, and can give grief to low power SETs that many of us love with our higher efficiency FR speakers.
As alluded in Al Wooley's thread re the Coral 8 & 10 horn systems for which he recently provided extensive measurements, "ragged" response can have it's charms.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=122197
Re: Newbs first build - Gabriel
Hello again,
Well I have a stake of wood in the spare room and some glue going off on the first few joints. The FEs have about 50 hours on them.
I have tried starting a thread but I keep getting told, "Please search the forum before posting.". What is the gig with that? If you can tell me what I am doing wrong, I would appreciated it.
I think it is fair to say I am hooked and I have only done three joints - on the speakers that is, my body is a temple 😉
Cheers,
Al
Hello again,
Well I have a stake of wood in the spare room and some glue going off on the first few joints. The FEs have about 50 hours on them.
I have tried starting a thread but I keep getting told, "Please search the forum before posting.". What is the gig with that? If you can tell me what I am doing wrong, I would appreciated it.
I think it is fair to say I am hooked and I have only done three joints - on the speakers that is, my body is a temple 😉
Cheers,
Al
Alistair72 said:
Click on the tick box to the top left where it says Please search before posting & away you go.
Gabriel Build Thread
Cheers Scottmoose.
I have started a thread (http://www.diyaudio.com/forums/showthread.php?s=&threadid=122510) but will have to wait till I have been moderated before adding pics.
Scottmoose said:
Cheers Scottmoose.
I have started a thread (http://www.diyaudio.com/forums/showthread.php?s=&threadid=122510) but will have to wait till I have been moderated before adding pics.