Looking for help - old box, new mid range - rebuild project.

[PLP]

My first post here. Thanks to everyone contributing here. I am not educated enough, in this area, to help others. I can be help in automotive, computers (hardware), chemistry, physics, and some others science related sections, so if you need some help, let me know.

I know something about sound... but not enough to create a good speaker from the pieces I have here.
First what I am looking for: soft, rich bass, clear enough highs. No need to be very loud. Those are garage speakers.

What I have.
I have old enclosures - two styles.
One is RAYAD of Boise (turned out two different models, although they look exactly same). Model SP-2 162-255 and 162-1XX (cannot read further - label is damaged).
Size: 18x25x41 cm (external). Sealed (not vented).
Old drivers were damaged... so I got new ones, from here.
https://www.parts-express.com/HiVi-M...Woofer-297-446
HiVi M8N 8" Aluminum / Magnesium Woofer

Now, it turned out that one of the tweeters is dead and that is the moment I discovered those two speakers are different models as they have different crossovers...
Tweeter is 1".

So, what I am looking for now is to fit HiVi M8Ns in there, match tweeter, and fit crossover.
Of course do not want to spend fortune...

If you need more info, please ask.
Thanks in advance.


EDIT.
Forgot to add - I got also some other enclosures, but they are in rough shape. Still usable, but some repairs to the back plug needs to be done.
Project 8, 19x27x47 cm.

[Kornbread]

Box is roughly ~.5ft³. If it's the cheap n thin variety, it will need lots of bracing. Thinking a tweeter that will play <2k. Off the top of my bald head, I'm thinking the da25bg is an affordable ($25) and robust tweeter that should be able to meet with that woofer. I'll have to model the box for that woofer later as PE doesn't have all the t/s data.

[Chris Roemer]

The M8s like a vented box twice your size, but in YOUR boxes (assuming 14L) they should do mid 50s w/a (highish) Qtc near 0.95.
Still, metal cones "ring" and your XO will need a notch filter to suppress that problem.

[PLP]

Thanks guys for your responses.


From what I read on the speakers specs I gather than in the boxes I have (they seem to be very solid, well glued, no cracks, thick material and overall heavy) I should get about 55 Hz.

Now, I am looking at two ways.
One is to replace tweeters and slap XO. Call them OK for now (or forever...).

Or, start as above, but in future - read summer time - get MDF and build a vented box that would drop the low to mid 20's.

Am I aiming too high?
I did a simple math and if I had something like 14x16x18 would be about what I need for the woofer. Some glue, a few screws, wiring, and done. Sounds too easy?
If I can rebuild old GM 3800 V6 I can put a box together, huh?

So if I was to take this a step further - can I get all the parts now to just get the speakers going and then, once I am done with the new build, move them to the new box?
In other words. Would I need different parts for the small and large box?

[Kornbread]

As box size, and yes, even baffle dimensions, alter the sound and load to the drivers, a change in size often requires a corresponding change in the crossover.

[Chris Roemer]

A 14x16x18" box (outside dims, 3/4" walls) w/a 3"id x 12" long port should get you into the upper 20s.

[JimHRB]

You have the woofers and have the boxes (and say they seem decent), I would continue down that path. The issue is a crossover that will work. Maybe someone here will help with that.

[PLP]

As box size, and yes, even baffle dimensions, alter the sound and load to the drivers, a change in size often requires a corresponding change in the crossover.

A 14x16x18" box (outside dims, 3/4" walls) w/a 3"id x 12" long port should get you into the upper 20s.

The box size was just some idea, just some numbers I came up with to make about 2.1 ft3 box.
So, basically the main questions here is: what do I need NOW to get them back to working condition.

Further down the line - would I be able to use the same stuff in the large vented box? I am pretty confident I will end up crafting the boxes. Hence, the I would be looking at getting all pieces now even if they are not perfect. They would not be destroyed, right?

You have the woofers and have the boxes (and say they seem decent), I would continue down that path. The issue is a crossover that will work. Maybe someone here will help with that.

Yes, I want to go this route for now. Just to get them going... but I am just lost what to use



The box I quoted: 14x16x18 was only one example.
Of course it could be 12x16x20 (all inches) or whatever else would work better.
I simply do not know.
Hence, if someone could run simulation, or whatever it takes, to get get some idea what box we are talking about and tweeters to match the woofers with the right crossover.
Also, if another woofer should be added... I am not sure if I am going the right way now, though That might be too much. So maybe I will stick to what I have, huh? Mid 20's is very good.

This pair is powered by Sherwood RX-4109 that I got a few couple ago.

[Chris Roemer]

Are you going to buy tweeters?

[Kornbread]

If I can find all the t/s parameters I'll sim some boxes. A 2ft³ box is going to be big while something around 1ft³ would have more waf, if the tradeoffs are acceptable.

Comparing apples to apples, 8" 2-ways are generally more difficult to get right than, say, a ~6" 2-way. Smaller drivers tend to play higher in freq more easily mating with the tweeter ... among other things. The ~2k breakup of the m8n will add to the complexity as that is very near where the crossover will be, that's one reason for the da25bg, or another tweeter that goes low. It can be done but I feel it's not going to be easy.

[PLP]

Are you going to buy tweeters?

Yes, I am.
The speakers (boxes), although looks exactly same on the first look, have two different tweeters where one is dead (it is dead, confirmed - beyond repair - unless I find the coil replacement), and also have two different crossovers. Maybe they are same in a sense of frequency switching, but they definitely look different.

If I can find all the t/s parameters I'll sim some boxes. A 2ft³ box is going to be big while something around 1ft³ would have more waf, if the tradeoffs are acceptable.

Comparing apples to apples, 8" 2-ways are generally more difficult to get right than, say, a ~6" 2-way. Smaller drivers tend to play higher in freq more easily mating with the tweeter ... among other things. The ~2k breakup of the m8n will add to the complexity as that is very near where the crossover will be, that's one reason for the da25bg, or another tweeter that goes low. It can be done but I feel it's not going to be easy.

I am not an audiophile that would spend 30k on pair of speakers. Even if I could afford, I would not.
I just need them to be well put together.

I am OK with some tradeoffs - if I get a decent volume and linear response from this box and woofer I have down to 50 Hz - I am OK. I do not expect them to rumble and shake windows. I know that well done 50 Hz will be better than poorly executed 25 Hz.
The garage is large, so I would need something much bigger...

Just FYI - the garage is 20x22x14 (all in feet).

[Chris Roemer]

Which ones?

[PLP]

Which ones?

Proper ones?

Chris, I honestly do not know. Hence I asked the question here.
I have decent boxes, woofers went bad and instead of fixing them, I got a new pair. Now, turns out the XO are different and one tweeter is dead.

So the bottom line - for about a 0.5 ft3 box I have M8N and I need to add matching tweeters with crossovers. As Kornbread suggested - da25bg would be a good match. Now to add XO and I might be all set.
Apparently building a new box is not the best approach... so I might drop this idea.

[Chris Roemer]

OK - the DA25BG08-06 it is!

(#264-1460 $26)

Your M8Ns in your current (approx. 0.5cf) cabs, sealed, and stuffed w/polyfill or fiberglass.
Woofer (Low-Pass) filter (6 elements), 2nd order (notched/tanked) w/Zobel-thingy:
2.0mH low-DCR (iron core - I'd use Dayton's) series coil w/a "bypass" (notch) made from a 4n(ohm) resistor and a tiny 1.5uF cap - in a series string, paralleled around that coil, then a 12uF shunt cap (to grnd) and a "Zobel" (also shunt) using a 7uF (approx.) cap and 10n resistor.

2nd order HP (tweeter) filter w/4 elements:
a 7uF series cap, then a 0.80mH shunt coil (can be #18 or #20), then an L-pad (for attenuation) using 5n series / and 4n parallel resistors.
Runs around 83dB w/full BSC (baffle-step), so away from walls (on stands maybe?)
8ohm load. Crosses around 1.8k or so.

Maybe $120 or so? ?

[PLP]

Thanks for the response. Looks like I might be powering them up soon!

Chris - only the first sentence made complete sense.
The rest is a bit more complex. While I can read and understands some of the parameters, I am not sure what I will be doing here
Excuse me my ignorance in the topic.
Do not get me wrong - I am capable of soldering and putting a few pieces together, but I need to know what I am exactly doing so that I will not mess things up.

Am I building the crossover from pieces here using the items listed?
Or it is already prebuilt that I simply install?