Alpine SPS-517 – Open Baffle Speakers

At the moment, I’m sorting out my home audio set up. I was inspired by PWK’s Dipoles where Pete uses a pair of Dayton Audio speakers ( ) and this design (images & link to the project below) where an Alpine SWS-1023D 10″ subwoofer has been used to help the low frequencies along. – copy and paste link into URL bar

Open baffle speaker design – room friendly dipoles -  3Open baffle speaker design – room friendly dipoles -  1Open baffle speaker design – room friendly dipoles -  2

This is where the Alpine speakers come in.

If my understanding on IB speaker and subwoofer designs is correct, one of the most common features sought for in a project like this, is for either the speaker of subwoofer to have a high QTS of around 0,5 or more.  My disastrous project with the Alpine SPR-69 6×9 speakers taught me one thing, focus on the project first and foremost, be true to the aims of your project (and realistic) and then find the components best suited to the project.

Of course I simple did this in reverse and did what 95% of people do. Find or buy components first, then try to get them to do what you want. It can work … sometimes, but the Alpines have such high Q’s, and my desired outcomes was near impossible.

I am being hard on myself. It was only until after I bought the SPR-69’s that I found out what the T/S parameters were (after contacting Alpine). As a consequence, I was also told that the SPG and/or SPS speakers also had very high Q’s. Its not a disaster and I wouldn’t anyone off buying Alpine speakers, far from it. They are superb speakers which I wish more people would choose over the many poor but expensive speakers. Yes Vibe springs to mind!

On with the Vibe bashing project

Quick test set up with a cardboard baffle


I’ve played around with a pair of Alpine SXE 1025s 4″ speakers, then moved up to a pair of Alpine SXE 1325s 5.25″ speakers. Now I’m onto a pair of Alpine Alpine SPS-517 5×7 speakers, and they really, really kick. I’ve got my Muse MU-15 MKII (15 watts @ 4 ohm) amp at about 12:30 on the volume dial, and that’s plenty enough!

Am I going to keep it pure Alpine.

I was looking at buying either a pair of Peerless SLS 6.5″ woofers (subwoofer) or go mad and buy a pair of Peerless XLS10 (P830452) subwoofers, and bi-amp the system. I have a Class D amp on the way. for reasons of size, I don’t really want to go bigger than 10″ subs.

And then for a dedicated subwoofer, I’m going to use my Sundown Audio SA-12.


6 thoughts on “Alpine SPS-517 – Open Baffle Speakers

  1. What are you driving these satelites with? I guess you need a good amp with a big enough damp factor to keep the Alpine woofers in check. I would have chosen for the widerange to be a little different for audiophile reasons and to better compile with the woofer in question. This is all confusing stuff, but as a speaker designer of 8 years in a world where every idea can and will be used to make money, its a caution thing.

    • At the time I was driving them with a 15 watts Muse Class-t amp. You are right, an amp with good damping factor will help, however sometimes, we have to work with;

      what we have
      … even prejudice for a particular brand.

      Everyone has theories, backed up with more theories. I take what I have learned and put it to use. Some results are good, some not so good. At times, I leave forums, graphs, measurements and conjecture aside, and let my ears tell me what’s right or wrong.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s