I see classic Teac there! I cut my teeth on an old Sony TC-200!!
-----------------------------------------------------------Rick............
So,
Lowthers are treated to a stealth pattern. By the by, the answer to whizzer cone screech is a 3 parts in ten coating of 2 way glue and filtered water, to the back side of the whizzer cone. Kills the side firing, out of time alignment signal just enough. Also keeps it from linking to the signal from the cone back side, around the short OB distance. Will be my treatment of choice for all whizzer cones going forward.
Teac has a new power transformer, caps, heads, pinch rollers and lube job. Sounds quite nice. One of the reasons I bought it is the availability of the heads and rollers, made by the original workers, who formed a company after Teac stopped making the parts available.
Yes, HPM super tweeters. EnABL patterns on the left and right edges are all that are needed, though a small dot of flat acrylic paint at 100% strength applied at the mid point of the curve helps with dispersion.
Since the pic is a fairly clear one you may be able to see where the pattern is placed on OB edge and at a position on the face of the baffle that was determined with the trusty tap test.
And finally, you can trust Alex's teachings. He is exactly correct, though, there is an addition or alternative to edge placement. It does require a very good understanding of tap test results and is only slightly more effective. You are suppressing the edge diffraction loops and some of them relate all the way back to the center point of the drivers.
Lowthers are treated to a stealth pattern. By the by, the answer to whizzer cone screech is a 3 parts in ten coating of 2 way glue and filtered water, to the back side of the whizzer cone. Kills the side firing, out of time alignment signal just enough. Also keeps it from linking to the signal from the cone back side, around the short OB distance. Will be my treatment of choice for all whizzer cones going forward.
Teac has a new power transformer, caps, heads, pinch rollers and lube job. Sounds quite nice. One of the reasons I bought it is the availability of the heads and rollers, made by the original workers, who formed a company after Teac stopped making the parts available.
Yes, HPM super tweeters. EnABL patterns on the left and right edges are all that are needed, though a small dot of flat acrylic paint at 100% strength applied at the mid point of the curve helps with dispersion.
Since the pic is a fairly clear one you may be able to see where the pattern is placed on OB edge and at a position on the face of the baffle that was determined with the trusty tap test.
And finally, you can trust Alex's teachings. He is exactly correct, though, there is an addition or alternative to edge placement. It does require a very good understanding of tap test results and is only slightly more effective. You are suppressing the edge diffraction loops and some of them relate all the way back to the center point of the drivers.
External baffle/panel treatment is still a WIP for me. I managed to do the front and top today. Tomorrow is another day. Measuring & cutting the blocks using an exacto blade takes time. The speaker cabinet looks fugly when treated though. Who cares!
I was thinking of applying a layer of diluted PVA on the pattern strips. Why? I don't know. If Microgloss coated on the pattern strips has an effect, maybe the PVA layer will have one too. Thoughts?
I was thinking of applying a layer of diluted PVA on the pattern strips. Why? I don't know. If Microgloss coated on the pattern strips has an effect, maybe the PVA layer will have one too. Thoughts?
Front baffle - patterns on edges, done.
Side panels - patterns on edges + vertical pattern down the middle, done.
Top panel - patterns on edges + horizontal pattern across the middle, done.
Changes from pre-cabinet treatment:
Till yesterday night, I'd just finished one speaker. I hooked one treated and the other untreated speaker and both the speakers definitely sounded different from each other. Today, with both treated, they've come into their own.
Alex and Bud: Thanks!!
Side panels - patterns on edges + vertical pattern down the middle, done.
Top panel - patterns on edges + horizontal pattern across the middle, done.
Changes from pre-cabinet treatment:
Diffuse sound!! Listening off axis is not much different than listening on-axis.
I also added a pattern horizontally across the front baffle between the tweeter and woofer. I don't know what good/bad changes that is causing.
Till yesterday night, I'd just finished one speaker. I hooked one treated and the other untreated speaker and both the speakers definitely sounded different from each other. Today, with both treated, they've come into their own.
Alex and Bud: Thanks!!
Hi Keith,
Thanks for sharing your impressions.
The 'diffuse' sound comes about from the reduction of audible diffraction that normally comes from the edges of the baffle and box. The result is that the position that you perceive the sounds coming from becomes completely unrelated to the position of the boxes. In my experience, once the audible box diffraction is reduced, I started hearing diffraction from other hard surfaces and edges behind or beside the boxes.
In regards to the strip across the front baffle, personally I feel this adds an unusual effect that to my ears was somewhat out of place. My preference is to treat the driver then the baffle edges and leave the rest of the front baffle alone (although I will use a tap test just to be sure). Listening over an extended time and personal preference should answer this one for you.
*
Bass can appear less because the distortion at the port is removed and the resonance inside the cabinet is released. So rather than being localised around the cabinet, it fills the room.
The edge treatment makes more sense if you think of the cabinet panels as very stiff drivers. The patterns not only impact on the sound travelling along the face of the panel but also serve to* release the sound travelling as vibration 'within' the panel material.
As Bud has said, the way to address the bass issue is to adjust stuffing inside the speaker and the port.
One other thing to experiment with is another pattern ring placed on the baffle immediately around the port.
At any rate, keep enjoying the journey as you unlock more from your music.
Cheers,
Alex
Hi Alex,
The horizontal strip on the front baffle does not cause any "weirdness" to my ears, so, for now, I'll keep it in place.
The nearfield loss of bass does not affect me in the least because at the position where I usually listen at, there's no shortage of bass, so, I'm not doing anything about that too.
The speakers have 2 ports - one exiting out the front and one out the back. The one one exiting out the back has the EnABL patterns at the inside surface of the pory at the exit and also on the baffle around the port exit. The port exiting out the front has a pattern shown in post #1102. Should I also do a pattern on the baffle around this port exit? The exit of this port is not flush with the baffle surface and is a little protruding like a lip.
The horizontal strip on the front baffle does not cause any "weirdness" to my ears, so, for now, I'll keep it in place.
The nearfield loss of bass does not affect me in the least because at the position where I usually listen at, there's no shortage of bass, so, I'm not doing anything about that too.
The speakers have 2 ports - one exiting out the front and one out the back. The one one exiting out the back has the EnABL patterns at the inside surface of the pory at the exit and also on the baffle around the port exit. The port exiting out the front has a pattern shown in post #1102. Should I also do a pattern on the baffle around this port exit? The exit of this port is not flush with the baffle surface and is a little protruding like a lip.
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Yes I would place a pattern ring on the front baffle around the port.
If you can get inside the cabinets, run a pattern on the inside surface of the opposite end of the ports (the end inside the cabinet) as well as a pattern on the outside surface of the port (again at the end that is inside the cabinet) is useful. If you do this, you may need to play with cabinet stuffing and port stuffing.
As you have been doing, do one side first, listen for the changes and then do the other side.
Cheers,
Alex
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Question for Alex: I read in one of your old posts that applying the pattern to the inner walls of speakers also makes a difference - I'm putting together small sealed speakers and was wondering if it would be worth "patterning" the inner walls. Would this make a difference to only ported and not sealed speakers? It involves some work [though not as much since these are relatively small] but still, I thought I'd ask before starting.
I intend applying the pattern to paper and then affixing the patterned paper to the inner walls of the cabinet. What block size and block pairs do I use?
I intend applying the pattern to paper and then affixing the patterned paper to the inner walls of the cabinet. What block size and block pairs do I use?
Hi Keith,
You might want to consider making the blocks out of 3mil thick acrylic shelf paper with a stick and peel adhesive on the back. Somewhat tedious to apply directly to the chamber surface, but I would be very surprised should your plan for blocks on a piece of paper work out. Others have used pieces of wood that stick up about 1/4" and reported good success.
Bud
You might want to consider making the blocks out of 3mil thick acrylic shelf paper with a stick and peel adhesive on the back. Somewhat tedious to apply directly to the chamber surface, but I would be very surprised should your plan for blocks on a piece of paper work out. Others have used pieces of wood that stick up about 1/4" and reported good success.
Bud
I could do thicker blocks too of maybe 0.8mm card stock if in your opinion, the electricians tape is too thin to have an effect.
Also, the BIG question is whether the blocks on the inner cabinet walls would have an effect in a SEALED cabinet.
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Not sure about a correct answer here. I would explore this using fairly narrow strips of underlay just big enough to contain the pattern. Something stiff enough that you can wedge it in place and thereby allowing you to move the entire strip laterally in small amounts. I have never bothered and my most recent system has no need that I can come up with. So, you are going to be investigating, not following.
I also think the biggest change is going to come from what you do to the back of the driver mounting board.
I would start off with a fairly robust thickness, with the intent to reduce this in stages. I would expect to do the four edges of both sidewalls first and if successful, top and bottom next. The back wall should be left to damping material, though I would expect a need for less and less as you find the correct position for the strips.
I also think the biggest change is going to come from what you do to the back of the driver mounting board.
I would start off with a fairly robust thickness, with the intent to reduce this in stages. I would expect to do the four edges of both sidewalls first and if successful, top and bottom next. The back wall should be left to damping material, though I would expect a need for less and less as you find the correct position for the strips.
Hi Keith,
Sorry for not getting back sooner I've been offline for a while. Are you able to provide dimensions and some photos of the speakers?
Cheers,
Alex