What ingredients to use in a music first subwoofer? (or two?)

[jakja83]

I have a pair of standmounts (Active AVI ADM9Ts) in a 4x5 meter room and I need to augment them below 100 hz. I am considering building one (or two) small, sealed subs that can fill in the bass part. I need them to sound very clean and to measure flat.

I don't listen very loud so I don't need extreme SPL, SQ is the priority.

I need hints and tips on what type of driver and what type of amplifier to use with them. I was hoping to get decent extension a bit lower than 25 hz.

All help is greatly appreciated.

[GM]

Hmm, flat to 25 Hz in a small sealed cab means either lots of room, boundary gain and/or lots of EQ and the power handling to use it, so high SQ may be hard to come by even at modest LF SPLs more felt than heard and until a driver can be found or some compromises made, there's no figuring out what amp to use, though for truly high SQ, it won't be a plate or prosound amp if not a recording studio grade $$$ unit.

GM

[infinia]

getting to 25 Hz is a problem (hardware driver) and is not necessary for a "music 1st" system. You should seriously re evaluate that spec esp for a sealed bass box. I think -6 dB at mid to low 30's Hz is more than reasonable for music. Maybe you could consider switching in another box (vented) and amp for HT LF effects when called for?

[DrDyna]

I've got a couple of subs that I use you might be interested in. The drivers are older Peerless 10"s that they don't make anymore, but I think you could probably use something like this:

https://www.madisound.com/store/prod...roducts_id=686

The cabinet is a really interesting ported design, like wedges that sit in the corners, which I and the designer refer to as "corner loaded". They don't occupy a whole lot of room, are fairly efficient and get down pretty low. I'd give you dimensions, but you'd probably have to recalc the internal volume and port for the new woofer anyway.



Edit: ignore the black box they are sitting on, those are my bipolars.

[Brett]

Not sure what you can get in the EU or if shipping is viable, but my generic choice for a modest size sub would be a Shive V2.

Originally Posted by GM

what amp to use, though for truly high SQ, it won't be a plate or prosound amp if not a recording studio grade $$$ unit.

GM

Plate amp, no, but there is no reason at all not to use a pro amp for a sub with an external xover/EQ, unless of course you want to spend lots more than you need to for no difference.

[Dr.EM]

This sub I designed might fit your requirements, though it's not the most straightforward build:

New subwoofer design, Hi-Vi D10G

It uses ordinary woofers, which do have great low end response, but they are used in this design really because I have them and wanted to see what could be done with them (and a 160W amplifier).

It is a music sub design which should have response to under 30Hz, low distortion, smooth, fast sound. Ideally sits in a corner. SPL is not too limited with the dual 10" drivers.

[studiotech]

Just a build a pair of these. You cannot do better for anywhere near the money.

Rythmik Audio 12" servo subwoofer " DS1200 Custom Installation subwoofer

See my 15" version here:

Sonotube style builds no longer en vogue... - AVS Forum

Greg

[5th element]

There is always the good ole' XLS from Peerless.

These work well in very small sealed enclosures. Attached is the driver in a 20 litre box with a LT, 100hz low pass and a subsonic filter. As can be seen the driver hits Xmax with only a small amount of amplifier power re 20hz. This results in a relatively low free field SPL @ 20hz, but if combined with room gain and boundary reinforcement (putting the sub in a corner), you can get about 95-98dB out of one. A 200 watt @ 4 ohm amplifier should be plenty too.

Build two of these and you'd be pretty well set.

Edit - the power required would be a little confusing, @ 20hz you need 70 watts into an 8 ohm load to hit xmax.

[jakja83]

I have been "tipsed" to prioritize the area above 30 hz and insted focus on making a sub that can produce a pretty flat response up to 100+ hz as my standmounts need some help further up.

I can get my hands on Peerless drivers fairly cheap. Both XLS and XXLS 10s and 12s, but perhaps they aren't the best drivers for upper bass performance?

I can also get drivers from Seas for a fair price e.g.

Seas driver info


What kind of amplifier do you suggest then? I could build 2 passive units and get a outboard amp, noe sweat - just need some concrete products to look up...

[infinia]

I see that there is an AVI 10' sub made for this system. Is there a problem going this route. Did you plan on using the digital inputs much?


Probably a system with two 12" peerless sealed subs could be very good choice with a separate amp, either a pro-sound or mid-fi amp >200 watts, not sure what your choices are over there. Before you select a sub woofer driver and alignment, The big choices you need to focus on, what is the best way to achieve the 'crossover' to the subs and integrate them the levels into your room space. I would find out what the built-in sub output filters do and how steep they are. Do they depend on using the natural LF response of the stand mounted mid-bass?? The most flexible in terms of integration and fine tuning things ( X-over frequencies ) and gains, would be using external crossovers, but then you would lose the digital inputs.