REL Britannia B1 Amp Plate.

[t0mmyt]

This is my first post so any help is appreciated. I've wound up with a REL Britannia B1 amp plate. Building a box will be a pleasure. Figuring out box size shouldn't be a big problem. My dilemma is what driver options should I consider. I'd like a ported box with a 12 to 15" driver. Obviously I can't configure my box until I find a driver. My budget is around $250.00. I've read lots of posts and can see you guys are a wealth of info. Whatever your willing to provide even if it's more than I'm requesting will be considered.

[Darren]

Have you considered the SoundSplinter RL-P15? I'm not familiar with the amp you bought. How much power does it have? The RL-P15 will require a bit of juice.

[t0mmyt]

The Amp is supposedly a true 500w. Judging by the numbers for the Soundsplinter drivers the 12" might be a good choice. I'll wait on more input.

[Darren]

Yup, with 500 watts you'll want to go ported. There are tons of drivers out there to play around with. I love the Acoustic Elegance AV15 with 500 watts in a ported enclosure but good luck finding one, that and I can't recommened them anymore due to poor customer service. The product is top notch though. I'm also quite fond of my RL-P15's and the customer service at SoundSplinter is very good.

[Exocer]

Yes, Sound splinter makes a good product indeed. IMO the SS Rl-p 15 always looked better than the 12 in vented allignments.

The Rl-p 12 wants to see a really small box, say 2ft^3-3.5 to stay relatively flat down to your choice of a tuning frequency. Requiring a small vented box raises the issue of possible port resonances creeping too low into the usable frequency range of the subwoofer. We would like to minimize port resonances any way we can. The only way we can do that in this situation is to increase box size, which will increase the peak right at the tuning point (this happens in this case because of high Bl aka strong motor). In other words you won't acheive the flattest frequency response with the 12" driver without severly underporting it or creating a huge peak around the tuning point while attemping to keep port resonance under control.

The rl-p 15 d2 models really well in a variety of box sizes and tuning frequencies.

Also, with a vented subwoofer it is very important to protect the driver from exceeding it's excursion capabilities below the tuning point.

In the following graph we're tuned to 16hz and by the time you're down to 14.5hz you're in danger of exceeding the excursion capabilities of the driver. A highpass filter around 15hz will help to protect the driver from trying to reach dangerously high SPL levels below the tuning point

You may want to look into finding out what frequency your Highpass filter is set to on your amp by getting in contact with the manufacturer.

[t0mmyt]

Wow, at this point the info is overwhelming. Here is some info I got that might be useful.Enclosure Type: Balanced ARM Loaded with Port
Port Diameter: 4.75 inches

Input Connectors: 2-Neutrik Speakon / 2-RCA Phono / 1-XLR
Gain Control Range: 80dB
Amplifier Type: DC Coupled MOSFET

Input Impedance: 100k Ohms, High Level, Two-Channel Unbalanced
100k Ohms, High Level, Single-Channel Balanced
10k Ohms, Low Level(LFE), Black 0dB, Red + 12dB
10k Ohms, Low Level, Single Channel Balanced

Drive Unit: 12 inch, Long Throw Heavy-Duty Cast Frame
Low Frequency Response: 13Hz in Room at 6dB
Power Output: 500 Watts
Phase: 0 and 180 degrees

These are the numbers for the actual manufacturer's complete unit. Hope this good info. I will be able to understand all your input in good time. Thanx.

[Exocer]

"Low Frequency Response: 13Hz in Room at 6dB "

hmmm wonder if the highpass is set to around 13hz.

Sorry to overwhelm you. Basically the jist of what I said is the 15" looks better for a vented sub than the 12" version especially if you have space for a larger subwoofer.

Are there any size constraints?

[t0mmyt]

Unless we're talking about the awesome yet massive sonobeast I don't have many restrictions. Here's a newbie question. Until I purchase a proper driver and build the box, can I safely drive my old 10'" JBL PSW-d110 sub with the REL amp? The amp module S53AMI bit the biscuit and is not made anymore. It's made the entire board useless to me. If I can drive the old sub box and driver for now I would be happy.

[Exocer]

I just went ahead and looked up the amplifier you'll be using and it appears that it was designed for a particular driver/box already. What this means is that this Rel amp probably has some form of internal boost or EQ, specific to the original driver/box. Without more detailed information I wouldn't try to power your JBL with this amp. For all you know there may be a ton of boost at a frequency below the tuning point of the JBL subwoofer, which could end up being dangerous.

Not sure I would consider this amp for a DIY project either without further information from the manufacturer unfortunately

[t0mmyt]

Taking into account what you said about the amp I did a little more digging. I don't believe there is any magical bass boost as REL's founder and designer seems against tricks like that. Next thing I learned is that the production sub is an ARM loaded design. More digging reveals this to be Acoustc Resistve Matrix. Again more digging. Several descriptions lead me to believe it's a hybrid transmission line with some secrets not to be revealed. Hmmmm. I can't back out of building this sub with this amp plate so my quest is now to gather TL info. Don't think I'll be able to reproduce their box but I should be able to come up with something. Your input is much appreciated I'm slowly learning more of what it all means. TL's don't scare me as I love a challenge in carpentry.

[Exocer]

Good digging!

Looks like you're headed in a good direction now