I recently tested the effect of felt between driver and microphone, because I wanted to see what, if any, phase alteration it might produce.
I didn’t see anything of significance on phase. I did see just over 2db attenuation per 3/16” layer looking like a very low q high shelf starting at about 1.8 kHz. The start frequency drops a bit as more layers added.
I was thinking it might be possible to create a front of driver passive filter that attenuated the on axis response but not as much off axis...I have since determined that with a 10 degree driver tilt back, I get even response over a +/-20 degree angle, and I don’t need response any wider than that.
So I can’t imagine why felt would impact, unless maybe the entire felt layer is moving?
Sorry, don’t know why my picture showed up inverted?
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I'm surprised you needed a super tweeter with the TAD. do you have measurements plots? Great looking speakers by the way.
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I've come across a very few other recordings where this happens.
Perhaps the small baffle surface area to driver area ratio, plus the boxless sound unmasks bass irregularities more than other speakers I have here.
Here my OB in my 9.5'x12' room.
FaitalPro 18fh500, supravox 215rtf64 and raal 140-15d.
In-room, without EQ ... not bad at all.
Subs was not playing.
I am using 300hz and 2.8k for the crossover.
I like 500hz and 2.8k too ...
I have 0 tuning done at the moment and they sound fabulous!
In the mesurement, I see some drop in the zone tweeter/mid, bass/mid plays. I have to generate a filter with the timing to be in phase.
FaitalPro 18fh500, supravox 215rtf64 and raal 140-15d.
An externally hosted image should be here but it was not working when we last tested it.
In-room, without EQ ... not bad at all.
Subs was not playing.
I am using 300hz and 2.8k for the crossover.
I like 500hz and 2.8k too ...
I have 0 tuning done at the moment and they sound fabulous!
In the mesurement, I see some drop in the zone tweeter/mid, bass/mid plays. I have to generate a filter with the timing to be in phase.
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Here's my current system using a horn + OB + woofer:
{Raspberry Pi4 running moOde, HiFiBerry Digi+ coaxial SPDIF out, FLAC files on HD and streaming internet radio}
or {windows PC, Topping D10 USB DAC, Toslink out for Amazon music, YouTube, or REW for measurement}
or {TCL Roku TV analog output}
or {modified AR-XA turntable, Grace 707 Mk II tonearm, Shure V15V, Curcio Daniel 2 phono preamp}
Into a miniDSP 4x10HD for xover / EQ, using all balanced outputs to:
4 channels of Modulus 86 amps powering 12" Tannoy dual concentrics (modern ones intended for use as ceiling speakers) on flat baffles
Crown XLS1000 powering Dayton RSS315HF woofers in sealed boxes, with Linkwitz transform to extend the LF response.
I'm still trying to eliminate some 'honk' from the tweeter, but the overall FR is pretty decent IMO.
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Driver shuffle.
Selenium D250x phenolic midrange driver in the horns now, and the Peerless compression tweeters are out, replaced by some older HiVi planar RT2II tweeters.
First order filtered, x-over points chosen for useability without volume pads.
Still using Dayton RSS 265 HF-04 drivers in sealed cabinets, handling bass first order til 125 hertz, 12" full range goes til 5000 hertz, Selenium 250x goes til 9000 hertz, where the isoplanars finish up.
Yaqin 300B doing the drivers you see, and a Behringer A500 driving the subs.
It's a strange amp, insofar as it seemed completely inadequate to drive bass for the first 3 or 4 days.
The fifth day, I kept creeping its trim pots down until settling on about half volume, to match the @ 100db/watt satellites' output levels.
Selenium D250x phenolic midrange driver in the horns now, and the Peerless compression tweeters are out, replaced by some older HiVi planar RT2II tweeters.
First order filtered, x-over points chosen for useability without volume pads.
Still using Dayton RSS 265 HF-04 drivers in sealed cabinets, handling bass first order til 125 hertz, 12" full range goes til 5000 hertz, Selenium 250x goes til 9000 hertz, where the isoplanars finish up.
Yaqin 300B doing the drivers you see, and a Behringer A500 driving the subs.
It's a strange amp, insofar as it seemed completely inadequate to drive bass for the first 3 or 4 days.
The fifth day, I kept creeping its trim pots down until settling on about half volume, to match the @ 100db/watt satellites' output levels.
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I did a lot of Grace 707/ARX modifications. But never put a V15 into it. I am not a fan of that cartridge. It may well be a source for honk.
dave
Any SQ evaluation I do is with CD's ripped to FLAC. I suspect the honk is more related to HOM's in the horn throat.
The V15 was high enough compliance to work well with the low-mass 707. It's pretty old now. I really should replace it but don't spin enough vinyl to want to spend much for a new cartridge. I had hum problems with Grado's, and haven't kept up with what decent budget cartridges are available.
Vinyl is like a box of chocolates. You never know what you'll get
The limits of my vinyl budget was reached with a new Project DC Carbon Debut, with tweaks to accomodate a new Denon DL-103 cartridge, and an acrylic platter.
After splurging on a nice little MOSFET MC and MM phonostage, I found I prefer it in MM mode, with a passive Beyerdynamics step up transformer.
Vinyl playback is more pleasant sounding to me, but it's unpredictable at times. unpredictable at times unpredictable at times...
I've never heard any home system that sounds like live music, but vinyl is the sound I grew up with, so it sounds more right to me.
For MM cartridges, I like the Shure MX97e, Grado Red, and Ortofon 2M Red, without breaking the budget.
The limits of my vinyl budget was reached with a new Project DC Carbon Debut, with tweaks to accomodate a new Denon DL-103 cartridge, and an acrylic platter.
After splurging on a nice little MOSFET MC and MM phonostage, I found I prefer it in MM mode, with a passive Beyerdynamics step up transformer.
Vinyl playback is more pleasant sounding to me, but it's unpredictable at times. unpredictable at times unpredictable at times...
I've never heard any home system that sounds like live music, but vinyl is the sound I grew up with, so it sounds more right to me.
If this is about the Goldring E2 cartridge, the blurb says "Specifically Designed for the Medium- and High-Mass Tonearms", of which the 707 is not. It's quite low mass, so it needs a high compliance cartridge.
Wrong conversation for this thread, anyway. Let's let it go.
Serving bass, two ways
A simple open baffle, 44x24", mounted under my TV, on the front of a writing table.
Two 15" 1525e, filtered each with a 12mH coil, powered with a 300B amp, which also powers my open baffle hybrid horns.
Having the woofers so close to each other gives them enough boost to play bass nicely louder than the same efficiency satellites, filtered first order at @ 150 hertz.
Those are two MA Alpair 7P, doing centre channel chores.
They cross with my processor's 130 hertz set digital 4th order filter, and work very well with the two 15" being so close.
With a mighty 10 watt stereo amp feeding each driver, together they keep up, and needed to be trimmed down 3db relative to the main speakers level.
As good as I need, but I still have 6 more 15" cluttering up the place, I'm thinking I'll do 2 in a sort of transmission line enclosure I've been imagining and tweaking in my head for about a year.
It should extend these drivers output to about 25 hertz, I think.
A simple open baffle, 44x24", mounted under my TV, on the front of a writing table.
Two 15" 1525e, filtered each with a 12mH coil, powered with a 300B amp, which also powers my open baffle hybrid horns.
Having the woofers so close to each other gives them enough boost to play bass nicely louder than the same efficiency satellites, filtered first order at @ 150 hertz.
Those are two MA Alpair 7P, doing centre channel chores.
They cross with my processor's 130 hertz set digital 4th order filter, and work very well with the two 15" being so close.
With a mighty 10 watt stereo amp feeding each driver, together they keep up, and needed to be trimmed down 3db relative to the main speakers level.
As good as I need, but I still have 6 more 15" cluttering up the place, I'm thinking I'll do 2 in a sort of transmission line enclosure I've been imagining and tweaking in my head for about a year.
It should extend these drivers output to about 25 hertz, I think.
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I like them a lot. Probably the 7s have a couple hundred hours on them, but we're only exposed to about 2000 hertz and up.
In this use, they're doing 130 hertz and up.
They manage to be lively sounding, without sounding bright.
I'd hoped two with 10 watts each would match the level of a single 12P, and in fact they exceed it.
I'm shocked at how fast the woofers go, and stop, with single ended tubes, instead of a bigger solid state amp on them.
I guess my plate amps will be for a different project.
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Hi there . How is the bass ? I will build something similar , with SupraVox 215RTF64 bi-cone this time , but no tweeter , the room is almost the same . Any resonance ? It has thump ?
Very nice, Darkheart.
And efforts to dampen the room with bass traps, some screen in the middle, plus, the repurposed couch pillows are cute.
Since you are completely digital for your crossovers, do give a try to the Harsch XO. I think it would work very well in your case, better than just 48dBs all around.
S. Harsch XO
And efforts to dampen the room with bass traps, some screen in the middle, plus, the repurposed couch pillows are cute.
Since you are completely digital for your crossovers, do give a try to the Harsch XO. I think it would work very well in your case, better than just 48dBs all around.
S. Harsch XO