Is this a good DIY sub deal?

**cassb** · **03-23-08, 05:31 PM**

I just finished building 4 of Ed Frias' "AR.com" bookshelf speakers. With only 6.5" mids, they need a subwoofer to fill out the bass range. My room is about 14'x18'x8' with a hard floor and walls. I play mostly acoustic music like jazz, newage and classical and some rock.

So I have no clue where to start, how much it will cost, what 'level' of quality I need, etc. I'll use this 4.1 system mostly for music and playing my keyboard and computer sounds through, so I'm interested in fidelity over loudness. What do you think?

Like, is this a good deal for about $400 incl. shipping?

http://www.partsexpress.com/pe/pshow...00-760&scqty=1

Or..... could I buy this driver:

http://www.partsexpress.com/pe/showd...number=295-460

and this amp:

http://www.partsexpress.com/pe/showd...number=300-804

and build my own cabinet for even less? I have no clue what size cabinet I would need or how to build it. But give me a plan to work from and I'll build it! :-)

Thanks!
Bryan

**BoomieMCT** · **03-23-08, 07:09 PM**

Those aren't bad and I do dearly love PE (I run two 12" Titanics myself) but if I were spending $400 right now I'd buy a Tempest-X ($185) or Shiva-X ($165) and a 500W Oaudio amp ($240). DIYcable is having free shipping this weekend too. If you are interested in music only and are sticking with PE I'd use the Reference HF line of subs before I'd use the Titanics.

As far as building a sub - I'd say go for it. If this is for music only I'd probably build a sealed sub just to save some space (also easier to make). You'd have to pick a driver before I can give you suggestions on what size to build.

**cassb** · **03-23-08, 08:24 PM**

Well, remember that $400 includes the cabinet too, so I'm actually looking for a driver/amp package to be around $250 or less. And I think 10" will do OK for my application - mostly music - no need for LFE or Home Theater use - so 40Hz is probably all I need. I'll build a HT sub at some other time when I upgrade my Onkyo HTIAB setup.

So, a sealed cabinet would be good. I'm sure I can find software to tell me the enclosure size I need given the driver's specs. I guess what I'm looking for is plans or a process to follow to build it.

Oh and one other "sub" question, 4 ohm vs. 8 ohm... what is the difference besides 8 ohm costing less? Given the same exact speaker in a 4 ohm or 8 ohm version, which is 'better?'

Thanks!

**BoomieMCT** · **03-23-08, 10:02 PM**

Quote:

cassb wrote:

Well, remember that $400 includes the cabinet too, so I'm actually looking for a driver/amp package to be around $250 or less. And I think 10" will do OK for my application - mostly music - no need for LFE or Home Theater use - so 40Hz is probably all I need. I'll build a HT sub at some other time when I upgrade my Onkyo HTIAB setup.

So, a sealed cabinet would be good. I'm sure I can find software to tell me the enclosure size I need given the driver's specs. I guess what I'm looking for is plans or a process to follow to build it.

Oh and one other "sub" question, 4 ohm vs. 8 ohm... what is the difference besides 8 ohm costing less? Given the same exact speaker in a 4 ohm or 8 ohm version, which is 'better?'

Thanks!

A small sealed cabinet is easy - just make a box of the right size with a cutout for the driver and a cutout for the amp. Make sure to take the volume of the driver into account when sizing. It might not be a bad idea to build in some bracing, but on a small enclosure that may not be needed.

4ohm drivers take higher current. Most sub amps are rated for 4 ohms. If you hook an 8 ohm driver up to it you'll only get about half the listed power.

**cassb** · **03-26-08, 04:41 PM**

I'm frozen in my tracks by all the choices for a DIY sub. All I want is a sealed sub, about a 250w plate amp, and a 10" or 12" driver for music. I will build the enclosure myself from 3/4" MDF from Home Depot if I can find out how to build it. I want to spend around $150 for the driver and around $100 for the amp. What do I do!? Help!

**Mike P.** · **03-26-08, 06:10 PM**

This would make a good combination and would fit into your budget.

http://www.torrentaudio.com/mistral12dvc-p-73.html
http://www.partsexpress.com/pe/showd...number=300-805

The sub would also work in a ported enclosure if you decide to change it in the future.

**BoomieMCT** · **03-26-08, 09:54 PM**

Quote:

Mike P. wrote:

This would make a good combination and would fit into your budget.

http://www.torrentaudio.com/mistral12dvc-p-73.html
http://www.partsexpress.com/pe/showd...number=300-805

The sub would also work in a ported enclosure if you decide to change it in the future.

+1

**cassb** · **03-27-08, 08:21 AM**

Quote:

Mike P. wrote:

This would make a good combination and would fit into your budget.

http://www.torrentaudio.com/mistral12dvc-p-73.html
http://www.partsexpress.com/pe/showd...number=300-805

The sub would also work in a ported enclosure if you decide to change it in the future.

Thank you! Yes, I have been eyeing that 240w plate amp at PE for a couple weeks. It seems like a great deal at $99. I was going to pair that with the Dayton RSS265HF-4 10" Reference HF Subwoofer, but these are out of stock until 4/23/08. How do these two compare? One is listed in metric and one is in English units.

It seems the heavier magnet on the Mistral would make it less sensitive or transient or whatever? I really don't know. If list prices are any indicator, then the Mistral is a better 'deal' at $90 vs. the Dayton at $115. But price means pretty much nothing.

Thanks for your help!
Bryan

**ringbearer3791** · **03-27-08, 08:50 AM**

In regards to your questions concerning building a box of the right size. I'd suggest WinISD as a modeling program. It's freeware for download and definitely use the WinISD Pro version. It's pretty simple to use, particularly for a sealed setup and will show you everything you need to know to decide what size box you want to use. Another program i use in conjunction with WinISD is BoxNotes. This is a simple program that let's you play with box dimensions once you've figured out the total enclosure volume you want and it has the added benefit of creating a cut list for you once you've decided on the dimensions. Hope this is helpful.

**BoomieMCT** · **03-27-08, 09:01 AM**

Quote:

cassb wrote:

Thank you! Yes, I have been eyeing that 240w plate amp at PE for a couple weeks. It seems like a great deal at $99. I was going to pair that with the Dayton RSS265HF-4 10" Reference HF Subwoofer, but these are out of stock until 4/23/08. How do these two compare? One is listed in metric and one is in English units.

It seems the heavier magnet on the Mistral would make it less sensitive or transient or whatever? I really don't know. If list prices are any indicator, then the Mistral is a better 'deal' at $90 vs. the Dayton at $115. But price means pretty much nothing.

Thanks for your help!
Bryan

If all you are using this for is music then I'd go with the 12" Dayton Reference HF subwoofer. 12" doesn't cost much more then 10" and you get more efficiency and a bit lower output. This driver will fit well into a sealed 1.5 cubic foot box which is not too big. There may be some cost benefit in s/h only ordering from PE - I don't know.

If you wanted something more multi-purpose then I'd go with the Minstral.

**cassb** · **03-27-08, 03:39 PM**

Quote:

BoomieMCT wrote:

If all you are using this for is music then I'd go with the 12" Dayton Reference HF subwoofer. 12" doesn't cost much more then 10" and you get more efficiency and a bit lower output. This driver will fit well into a sealed 1.5 cubic foot box which is not too big. There may be some cost benefit in s/h only ordering from PE - I don't know.

If you wanted something more multi-purpose then I'd go with the Mistral.

That settles it. I will find the Dayton 12" HF speaker and the Dayton 240w amp (with no bass boost!) somewhere, somehow, and I will buy them. Then I will design a sealed enclosure for it (with WinISD) and build it. Only then will I be truly happy.

**BoomieMCT** · **03-27-08, 07:42 PM**

Quote:

cassb wrote:

That settles it. I will find the Dayton 12" HF speaker and the Dayton 240w amp (with no bass boost!) somewhere, somehow, and I will buy them. Then I will design a sealed enclosure for it (with WinISD) and build it. Only then will I be truly happy.

You may want to model them in WinISD before you buy to verify it is doing what you want.

**cassb** · **03-27-08, 09:03 PM**

Quote:

BoomieMCT wrote:

You may want to model them in WinISD before you buy to verify it is doing what you want.

OK, that I did, and it makes a nice yellow line that rolls off starting at about 100Hz. I don't know what that is telling me, but it appears to have some audible frequencies below 50Hz or so, which is fine with me. :-) This program has come up with an "optimum" sealed box size (with 3/4" MDF) of 53.7 liters, or:

Width = 16.5”
Height = 25.5”
Depth = 10.4”

So, I'm good to go. Now I just have to get the parts!

**BoomieMCT** · **03-27-08, 09:44 PM**

Quote:

cassb wrote:

OK, that I did, and it makes a nice yellow line that rolls off starting at about 100Hz. I don't know what that is telling me, but it appears to have some audible frequencies below 50Hz or so, which is fine with me. :-) This program has come up with an "optimum" sealed box size (with 3/4" MDF) of 53.7 liters, or:

Width = 16.5”
Height = 25.5”
Depth = 10.4”

So, I'm good to go. Now I just have to get the parts!

What you want is not just "audible frequencies" but you want it to be flat as low as possible. Many people use the "F3" point, or where the rolloff is 3 decibel below the peak. The other thing you want to make sure is that the driver is not exceeding xmax over the range you intend to use it.

**cassb** · **03-28-08, 07:55 AM**

Quote:

BoomieMCT wrote:

What you want is not just "audible frequencies" but you want it to be flat as low as possible. Many people use the "F3" point, or where the rolloff is 3 decibel below the peak. The other thing you want to make sure is that the driver is not exceeding xmax over the range you intend to use it.

OK, well the Dayton RSS315HF-4 hits the -3dB line at about 37Hz, which is fine with me. I'm still going to buy it, dang it! Stop trying to make me think!

**evad** · **03-28-08, 10:51 AM**

Quote:

BoomieMCT wrote:

If all you are using this for is music then I'd go with the 12" Dayton Reference HF subwoofer. 12" doesn't cost much more then 10" and you get more efficiency and a bit lower output. This driver will fit well into a sealed 1.5 cubic foot box which is not too big. There may be some cost benefit in s/h only ordering from PE - I don't know.

If you wanted something more multi-purpose then I'd go with the Minstral.

Hello All, I too am interested an a sealed RSS315HF system maybe two. In my research and reading on this site and others, the driver in question gets good reviews for music, but for some reason it's dismissed as a HT driver in favor of the ShivaX or others popular drivers. The reason I'm hangin' in, is Zaph. He uses it in a 60-62L enclosure and is very pleased. I'm thinking a lower Q, 70-75L with an O audio 300 plate amp. My useage will be 50/50 music and HT. I'm a noobie and need all the help I can get and I'm not too proud to beg.
I'm jumping in to this thread for advice and to wish the OP good luck and post your progress.

**cassb** · **03-28-08, 11:55 AM**

Quote:

evad wrote:

He uses it in a 60-62L enclosure and is very pleased. I'm thinking a lower Q, 70-75L with an O audio 300 plate amp. My useage will be 50/50 music and HT. I'm a noobie and need all the help I can get and I'm not too proud to beg.
I'm jumping in to this thread for advice and to wish the OP good luck and post your progress.

The WinISD program gives me an ideal enclosure size of 53.7l for this driver. How did you come up with 60-62 or 70-75? Will that allow lower bass at a cost of efficiency?

**BoomieMCT** · **03-28-08, 12:45 PM**

Quote:

cassb wrote:

OK, well the Dayton RSS315HF-4 hits the -3dB line at about 37Hz, which is fine with me. I'm still going to buy it, dang it! Stop trying to make me think!

Well . . . buy it, build it then post a write-up!

**cassb** · **03-28-08, 12:57 PM**

Quote:

BoomieMCT wrote:

Well . . . buy it, build it then post a write-up!

You got it, my friend.

Edit: Won the SA240 auction on eBay, and bought the RSS315 new at PartsExpress. Should arrive next Tuesday. I'll be getting some MDF this weekend!

**evad** · **03-28-08, 02:46 PM**

Quote:

cassb wrote:

The WinISD program gives me an ideal enclosure size of 53.7l for this driver. How did you come up with 60-62 or 70-75? Will that allow lower bass at a cost of efficiency?

Greetings cassb,

I'm glad you started this thread. I'm not a pro at winISD. I was told that the net volume of 53L would yield a Q of .707 and more L's means lower Q, shallower roll-off, and more efficiency. If it's too big, I'll put in more bracing or a diagonal shelf across one or two corners to lower the volume.
But I also have more questions than answers. Good luck with your build, evad

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