need quick help with A10.3 info !

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
I've now painted the inside of the bottom of the box black so the port will look dark when viewed from outside of the box.

I'm not planning to make it adjustable in the future, rather it will be a fully glued up box. I've installed polyfill batting, the kind you get for making quilts. It's very similar to what I used for my micro-castle build and I used a very similar density. However, this turns out to be quite a bit less than recommended in the pdf build instructions, more like half the density. I'm not to excited about the idea of putting a higher density in there, not because I'd have to do more work, but it already seems a fair bit of stuffing. I don't know if this design favours being over or under damped but I suspect the latter is preferable to the former. Does anybody have some experience with this to offer ?
 
No takers ?

I have the boxes playing in my basement system. But I don't know how best to tune the stuffing since I have no reference to compare them with. I can compare with multi-way PMCs but this may not be a fair race. So ... what advice on tuning ?

I assume that I'm tuning for bass. Too much and it's over damped, too little and the FR is lumpy. What else ??
 
Are the drivers fully broken in yet?( i.e 200-300 hrs of soft-core)

I can't keep track of my own projects, much less the myriad of others, but my experience with F & MA branded drivers over the past dozen years would make me cautious re dialing in the tuning or buttoning up the enclosures until the drivers have settled in.
 
They have about 200 hours on them.

I have calculated that I have only installed half the recommended poly-fill. I have about 11oz per box, installed in the space just below the driver to just above the port. My calculation tells me that I should have 25oz per box. My thought is to double the amount I have so that it matches the design guideline in the pdf plan document. I have double checked the port size and the opening is slightly larger than plan, by around 1/16".

The clarity in the treble is astonishing and imaging is excellent. With the current level of stuffing the bass extension is there, it's smooth & lacks no punch - very dynamic. However, the level of bass is lower than I would expect, it feels to be missing 'weight' in the lower registers.

fyi - I'm using YBA CD source, through Bryston BP60 amp and Zu audio cables.
 
Got a tube amp handy? Even as low power as 2A3 SE should demonstrate the bandwidth, if not ultimate SPLs of which these guys are capable - but be aware that while the latest incarnation of the 10metals are more efficient, they don't have quite the extension of the 10.2s in the same type of enclosure.
 
FWIW - I glued my front baffle on (face palm) then had to figure out how to do the scallops afterwards. I got a large/long jigsaw bit and reversed it in the jigsaw itself, then used it as a carving tool from the outside of the baffle. It worked exceptionally well, I allowed the teeth to start to cut and shifted the tool left and right, ate away some very respectable scallops.

My experience has been that the bass started to gain authority after the 200 hour mark, and they seemed to improve again after I gave them some muscular volume to deal with. Its definitely enough bass for me and it continues to improve slowly, but I accept that a pronounced visceral bass response is asking too much and I wouldn't want to sacrifice any of the glorious things these drivers do so well!

The soundstage! I occasionally ask myself if I installed another driver in my sleep one night, certain instruments seem to be originating from impossible places.
 
Jeff - 20 grams is only 0.7 oz ?

Well I moved the stuffing in one speaker upwards so that it goes right up to the top of the box. I guess it probably ends about half way down the box.

Rather than change the bass it sounds to me as if it has smoothed the top end - perhaps by adding a bit more absorption behind the driver itself.

I am listening to some 'pop' which allows me to hear the bass capabilities of the cabs. But the overall tone is clearly tilted upwards - too much. It either wants more bass, or less top end. It's not a peakiness, just an overall tilt that I am hearing.
 
No obvious wiring error - I also used the balance control on the amplifier to listen to just one speaker at a time, the tilt in response is quite evident with only one speaker playing. I feel as I'm driving blind right now as I have not done the modelling of these speakers. With most of my projects I get a sense for the outcome and the sensitivity of performance to the parameters. In this case I don't have any such data or intuition to guide me so I'll need to do some more playing around yet.
 
Tube amp with lower damping factor does sound different, but this isn't the answer. Either the drivers need more cooking, the stuffing needs to be changed, the port needs to be finessed, or as my tag line says - I have to change my mind :D


OK - just tried taking all the stuffing out of one speaker. It made a noticeable improvement in bottom end fullness - it's late I need to experiment further. This is a bit scary, this box design is supposed to require a LOT of stuffing ?
 
Last edited:
or as my tag line says - I have to change my mind :D


OK - just tried taking all the stuffing out of one speaker. It made a noticeable improvement in bottom end fullness - it's late I need to experiment further. This is a bit scary, this box design is supposed to require a LOT of stuffing ?

Fluff up the polyfill and try distributing lightly throughout the cabinet... not too tightly packed... keep the port free. Give the drivers a bit of space to breath - don't place the fill too near the back of the drivers. Without any polyfill you are likely to get a bit of boom...
 
HI zman01,

I agree with you - it is the next logical step. And so that's what I'm listening to now. I've taken out the stuffing, fluffed it up and put back half of what I had. It sounds like the best tradeoff so far. I must admit I was expecting more bass from the size of the cabinet after building with the EL-70 in a relatively small cabinet. But the sound of the A10.3 is quite a step above the EL-70 for refinement in my opinion based on limited listening so far.

I will not glue the base on these boxes, but keep them as removable. I prefer this to the removable back because the glued on back allows me to maintain some solid glue joints and front-back bracing.

There is still a bit of an upward tilt, but I'm going to reserve judgment until the boxes are finished and the drivers have more hours on them. It maybe that there isn't enough BSC built into the driver response.
 
So it seems. However, what it does do, it appears to do rather well.

What does Mark have that can reach down like an EL-70 but have the finesse of the 10.3?


I've been known to wax rhapsodic about the EL70 and A7s - the 10P is very nice - perhaps not quite a grunty as the EL70, but far more refined. O course if I was a betting man, I'd consider waiting for the (so far imaginary) A8 paper.
 
Bob - thanks for sharing your experience, I agree, some toe-in does help but it means a restricted sweet-spot ? so you use any network parts, such as zobel in your build ?

Try toeing them out 10-15*. In my HT, I have the speakers square with the room. Makes for a quite large sweet spot. I can move the sweet spot moderately by adjusting the volume on one of the speakers.

I use a BSC filter and a "zobel" on TB's and Fostex, but I ship MA speakers without any filters. For personal use, I clean up whatever with mild DSP.

Bob
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.