Monday, December 22, 2014

Polk R150 Review: Silly looking R15 and T15 clone?

Polk R150 Review: Silly looking R15 and T15 clone?

One of my first reviews was of the PolkT15, a simple bookshelf speaker found on sale at Best Buy for $49.99. From all the information I can gather; the T15 and the R15 use the same drivers and crossovers, however the T15 is front ported and R15 is rear ported. So those differences made little bit of sense from a users point of view. 

This brings us to the Polk R150, kind of an oddball bookshelf speaker. With it's tweeter placed below the mid (but nothing indicative of this being for any technical benefit). I can only imagine that this bookshelf along with it's sister speakers, exist only to be sold as door buster items. From what I can tell, none of these speakers are currently found listed on Polk's product pages as it is.

I went in to this review with the idea that the R150 probably is just the T/R15 flipped upside down, and missing any sort of wall hanger built in if you were looking for that. Between the two, I though the T15 was a better looking speaker, it's easier on the eyes but over all construction quality seems to be about equal. It's when I took apart the R150 that it was confirmed that they share at least the exact mid-range (they all have r15 printed on them. And while the tweeter on the R150 didn't have R15 printed on it like the T15 did, it's of the exact same size and visually identical. Seeing all this, I have to assume that they are nearly identical speakers (though I do hope to get new close mic and 1m measurements of the T15 soon)

Listening was done in different rooms and it has been a long while since I spent any time with the T15s. I did find the bass response very lacking, with the sister speaker the T15 to be slightly superior, I think due to the front firing port. Overall the R150 sound remarkably similar (the same?) to the T15's from the mid-range and up. By far the biggest issue is with vocal reproduction. In everything I listened to they just seem layered on top everything else, and not in a good way. But like vocals were cut out of construction paper and glued over the music playing behind them. It is very distracting when you hear it. The cheap tweeters are just not very articulate and with the significant boost after 10khz (see measurements) that are pretty fatiguing.

While music reproduction is not these speakers strong point, I could see them being used in a more home theater like situation where the ability to hear vocals may take priority. However their remain options that would do both better.

Unless you need some Polk bookshelf's to use as surround speakers, I would look into many of the other offerings at similar price points.

Disassembly Pictures

Above is a album of the speaker and it's components. It's as well made as any of the other $50 bookshelf speakers. At it's "retail" price, other offerings are both better performers and better built, the Pioneer BS22 and Infinity Primus options are easy step ups. If you are reeeaaaallly looking to stay in the sub $50 a pair price point, it remains hard to beat the Dayton B652 AIR.

Measurement Album

Close mic driver measurements

@1 meter

Above are the measurements I took. Both the close mic-ing of individual drivers and single speaker 1 meter responses indoors and outdoors.

From the individual driver measurements, we can tell that the mid-range doesn’t have very good lower extension. It really taps out at 100hz, where it takes a very steep nose dive. In theory, I guess the ports output could help make up for that steep fall off, as my measurements give it good output to about 40hz, though I highly doubt you would get close to that in an actual listening environment. The mid gets a little ugly between 1khz and 3khz, where it's crossover point. Tweeter measurements with and without the grills are pretty similar. At least the grills don't kill them like they do on the Pioneer BS22. However their output rises quickly and large peak after 10khz.

In my 1 meter measurements many of these issues can be seen manifested to various degrees. With the in room measurements, the Polk R150 shares the common bump from 100-200hz that rear ported speakers show in my room. Just as in the close mic measurements, the ugliness 1khz-3khz can be seen and is even more problematic thanks to it also being in the middle of a 10db hump. This is where I think much of the problem lies. It doesn't help that there also exists a pretty good size valley after it that then grows in the a nasty spike at from 9-16khz. These is one situation that presented it self in both the T15 and R150 regardless of measuring techniques. I think it shows that something it fundamentally wrong with the speaker.

Overall, this is another speaker to avoid.


The upside down version of the R15 and T15. Not very musical, sound bad and Polk should feel bad. If you are only going to spend $50, get the Dayton B652 AIR. The R150 might be ok if you really need a cheap Polk surround speaker.

Wednesday, November 12, 2014

The new Dayton Audio B452: Disassembly and on axis frequency response graphs.

The new Dayton Audio B452: Disassembly and on axis frequency response graphs. 

The Dayton Audio B652 has been one of the go to ultra budget bookshelf speakers. It is not a perfect speaker by any stretch, but wt it's price point it is hard is near impossible to beat. And for those looking for 2.0 set up that beats a sound bar or desktop PC speakers; it fits those requirements pretty well.

Dayton has been pretty active over the recent months with the release of the B652 Air, the T652 Tower speakers, and these smaller B452 bookshelf speakers I am writing about now.

So how do these smaller, B452 bookshelf speakers compare to their older and larger sibling? Well I have not been able to do a real sit down and AB listening test. Time has not been on my side and the left channel on my AudioSource Amp One is beginning to go out on me. So at this time the best I can do it some measurements and disassemble pictures.

Overall fit and finish matches the rest of the current Dayton offerings just fine. However there was one new addition to the B452 that was rather interesting. That is the addition of a slightly more complex crossover. Now, I don't know anything about crossover design, but this new one includes a resistor in addition to single capacitor. So some different sort of black magic is happening.

After giving these some time to break in, the first thing I noticed is that there are really inefficient speakers. You will have to crank the volume pretty high to get much usable output. After giving them a through listen, it's that usable output that is a problem.

To make it short, these are bad. Like really really bad. Dayton should not be proud of these. It's hard to imagine these being used by anyone. If you need small speaker with a 4 inch driver, go straight to the Infinity Primus p143, if you can't find those, the Micca MB42x will probably be a good choice.

Comparing the Dayton B452 to the Teac LS-H265 just isn't fair, Granted that Teac's are now about 5x the price of the Dayton's, but the Teac's are one of the great examples of budget options out there.

Album of Dayton Audio B452 disassembly

Album of Dayton B452 and B652 close mic driver graphs & 1m

So what can we gather about the new B452? Let's take a look at the graphs and see.

Dayton B652 and B452 outdoors @1 meter

Top = B652, Bottom = B452

There is a very large difference in speaker efficiency here. 84 dB 1W/1m for the B462 vs 87 dB 1W/1m for the B652.You can see that these two speakers share very little similarities after 1.5khz. The B452 begins it's drop off in output as early as 150hz.

Where as the B652 has hits awful cone break up at 4lkz, the B452 has a large dip in the response between  ~1.5khz and 5khz. This is also very clearly seen in the individual driver graphs that follow.

Dayton B652 and B452 outdoors close mic

From these graphs we can see that the mid plays relatively flat from 100hz to ~1.5khz (I know nothing about cross over design, but the B452 introduces a resistor into the mix, instead of the B652's single capacitor on the tweeter)

But is that early and step decrease in output on the mid and fact that the tweeter doesn't gain any real steam until 5khz that seems to have causes the significant dip between  ~1.5khz and 5khz as seen in the 1m graphs.

The cone break up appears to be pushed higher up into the 5-6khz range.

That tweeter also seems to be spiting some fire after 10khz. The tweeters in the B452 look the same as the tweeters in the B652 but at least via measurements, the sure don't seem to perform the same. Something is different.

Dayton B652 outdoors close mic

Seen above is the same type of measurement done for the B652, There were done at the some time as the B452 just to eliminate as many variables as possible.


These speakers are bad and Dayton should feel bad. Spend your money on Keystone Light instead. 

Friday, October 24, 2014

Teac LS-H265: The latest new hotness cheap speaker on the internet. First impressions and measurements

So I jumped on the internet bandwagon and picked up a pair of these Teac LS-H265B's for $90. I must have gotten in early because they are currently just above $160 on amazon.

I did some very preliminary listening and took some measurements of the speaker. Overall, it seems like a good buy at about $100. The close mic measurements and even the in room measurements are very good.

Album of speaker boxing, disassembly, driver and box details.

Here are the quick measurements. These are right out of the box and look pretty good.

Looks like the port is tuned to 60hz and at the mid and tweeter are crossed over at 2.5khz. 

Overall really flat (+/- 3db) from 700hz to ~15k where there is a steep and sudden drop off. Everthing below that is probably due to some room issue. With my common hump ~150hz, but it is actually pretty marginal and only really there because of the slight dip from 200hz to 600hz. Those these are lacking in the bass department, with a fast drop off at 100 hz. These will need a sub or at least some rear wall. (UPDATE: In retrospect after seeing the outdoor measurements, I'm not sure that the TEAC's are as deficient in bass response as I initially though, I do think the driver has broken in a little with additional use, and the in room bump from 100-200hz may have made seem to produce less bass than they actually do. However I would still recommend a subwoofer to be used with this or have placement a bit closer to a rear wall than my testing location allows.)

Above are some comparisons between the indoor and outdoor responses. Very similar results above 800hz in both situations. Outdoors and away from reflection, these speakers measure pretty darn good. with a slight rise in output as you get above 4khz. Even indoors, it wouldn't be hard to EQ down my 100hz-200hz hump.

A 15 minutes listening session AB testing the Teac LS-H265 vs the Pioneer BS22, I found that the Pioneers sounded much warmer, and had a little bit better bass extension. I haven't yet done a detailed test of the Pioneers to get comparison graphs going on, but I would  guess that their tweeter is a little less bright also. (measurements have shown the grills are a huge killer on the Pioneers)

The Teac's to lack in the bass department and should be pair with a sub, particularity if they are not going to be near a back wall. The more I listen to the Teac's the more the bass has developed and I think for many people and types of music they will be just fine as far as bookshelf speakers go. But they are very clear and articulate speakers and I enjoy them very much. At $100 they are exactly what budget audiophile should be looking for. However with their recent popularity, prices have gone up into the $160 range. The biggest disappointment was their construction quality, for something with a retail price of $250 they are not built nearly as well as many of the other go to budget speaker out there.


If these are in your budget and you like the high gloss black finish, you can't go wrong with the Teac LS-H265.

Thursday, October 23, 2014

My experience with the Definitive Technology Studiomonitor 45/65's. Measurements and short Review

My experience with the Definitive Technology Studiomonitor 45/65's. Measurements and short Review

A while ago I did a comparison between the Pinnacle DB 500 and the previous generation Definitive Technology Studiomonitor 350's. I found both to be very enjoyable but the SM 350s suited my tastes more and thus kept a place on my shelf.

When I got the opportunity to buy these new generation Studiomonitors at an insanely cheap price thanks to a lazy Best Buy employee, I couldn't pass them up ($150 for the pair). They immediately went to use in a 2.1 home theater system. I quickly added 3 Studiomonitor 65's as my front 3 and moved the 45's to the rear. In this application they worked well enough, but I always had this sense that they were a little dull; they didn't seem to live up to the reviews, and I kept wanting to go back to the previous generation Def Techs.

So after a while, and after switching to a Pinnacle (BD 650 II/700 II) front 3, I started to focus on the Def Techs as music only speakers, I had such a good experience with the 350's I thought that the 45s and 65's would be amazing. Unfortunately things immediately sounded off, just muddy,dull, lifeless. All those adjectives that someone would use when they are not impressed by a speaker. Many ABX tests with other speakers and a few dozen attempts at in room measurements, I just couldn't figure out why there is such a disparity between my experience with them and all the other positive reviews on the web. I still don't know what in my room that has contributed so greatly to my issues with these speakers and not others.

While the Definitive Technology SM 45 and 65's don't sound or graph all that well in my room, my close mic measurements were nearly identical to what Stereophile produced. So I do not have the ability to say these are bad speakers, only that they didn't work in my situation and it's been a great lesson in trying to listen before you buy.

Album of pictures of speaker and drivers
Album of Graphs

Each graph has two measurements on it. RED is the outdoor close mic measurements, BLUE is the indoor close mic measurements WITH any other driver unplugged. So during the tweeter measurement, the midrange is unplugged and vice versa.

All Driver Measurements @ 1 inch. No smoothing


Port look to be tuned to 45hz. Something loud and ugly is happening between 700hz and 900hz. Not sure of the cause to that, but it is seen again during the midrange response.

Drivers have a steep fall off @ 80hz and crashes to 50hz where there is another bump @ 35hz. Looks like a rather shallow xover at ~2.2khz


Similar shallow xover. Pretty smooth slightly rising response.


Matches very well to the measurements posted by So I'm confident that my close mic measurements are accurate.

Measurements @ 1 meter



The outdoor responses (IN RED) between the 45's and the 65's shared the same characteristics. Keeping the huge hump that exists from 90hz to 200hz. This I imagine was the primary cause of the muddiness. Then the steady decline to 1khz, then a similar climb after 1khz and into the rest of the spectrum.

These speakers just behave terribly in my room (IN BLUE). Even with anticipating room reflections and modes that are going to wreak havoc on any graph, I’m still at a bit of a loss as to why they are sounding as they are.

In my situation, the SM 45s and 65’s sounded and graphed more similar to the Sony B-1000 (

 than my budget favorite Infinity Primus p143 in red. (

I will update to a single picture ASAP

The Def Techs are good looking and really well build. Massive heavy drivers that scream high quality. Their outdoor measurements indicate that they should be very good speakers, but they just do not seem to produce those same results in my room. I'm going to have to assume this is a one off experience and that I'm in the minority here. 

However this has been a great learning experience demonstrating how just one room can drastically affect sound and how if you are willing to spend this amount of money on some speakers you should do your best to try to listen to them before hand and even better see if your retailer of choice has a decent return policy if they don't work for your application.  

For now, I'll be keeping my previous generation Definitive Technology StudioMonitors. Below is a comparison between the 45 and 350's. The 350's are noticeably brighter and louder. This combo seems to not be as effected to my room conditions. 

Thursday, September 18, 2014

Does it pound?!?! DIY Home Depot Bucket Subwoofer using a Peerless 8 inch driver and BASH 300S amp

Here is my bucket subwoofer. While being bored during some down time at work, I looked for new DIY project and stumbled up this:

A small subwoofer using a 5 gallon bucket as an enclosure, awesome right?

So I gave it a shot; made some adjustments along the way and learned a good bit. Overall it was fun, but not without a few frustrations. I might have to try the sump sub next.:

Full album of step by step creation.

I started off with just a $3 Home Depot bucket and a dream.

I then cut the hole for the Peerless SLS 830667 Paper Cone Subwoofer and glued the hell of our the top and hammer it on to the bucket with a rubber mallet.

I decided to try and port this one, but I also wanted to give myself an easy out just in case I totally screwed up. So I integrated a way to close off the port and seal up the enclosure. 

Porting it seems to have worked well enough. From my fuzzy math it should be tuned to about 30hz. Did that actually happen? Probably not. See the test results at the end.

Concrete is poured in, about 1.5 inches deep and left to dry for a few days

Attaching the wood baffle for the driver, this is where I learned that these types of buckets are near impossible to actual glue anything to.  Polypropylene and Polyethylene low energy or inert or something else all sciency so 3M made an expensive magic glue to work on them. Thank God for screws then. When the cut out was made for the woofer, a lot of tension was taken off the bottom of the bucket which caused the left over "lip" that I was trying to mount the baffle to, to angle into the bucket. The glue and screws were an attempt to pull that lip back up and get a secure mounting surface. 

Painting time. I used truck bed liner, which also doesn't stick very well. But once it cures its tough enough to not flake off immediately. Never mind the nearly dead grass, this is California and if you have green grass right now then F you. 

Cheap, crappy speaker terminals form Radio Shack. Never again.

Mounting the woofer and putting some stuffing in. A whole bunch more as added just after this picture


Since the subwoofer enclosure is made of a bucket, I needed some where or someway to mount the BASH 300S plate amp. So since we are working with plastics, I found a handing file box at Staples that suited the amp well enough.

The future amp box

Drilling some pretty pretty air vent holes. I used a checker board pattern to make them nice and even-ish

Cut out for the amp done


So how did this thing actually turn out?

From just listening to music and watching a few movies, it definitely provides some kick and sounds pretty alright to me. Much louder than the Dayton Sub-800 that I normally have on all the time; and I think it might be darn close to besting the Dayton Sub-1200. Getting into more technical understanding on how well it blends or transient response and all that, Im not the best judge. I'm a car audio bass head who rolls around with an 18 in the back of my Ford Fusion so you can see where my priorities lie.

But I did take some in room responses so at least we can see a little bit of the technical results. So check these out. As a note, I'm still having trouble with REW, Dayton UMM 6 and my PC getting a consistent overall volume. You'll note that the graphs are centered around the 100 db mark, just prior to these testings, I was getting results centered around 80 db. Graphs look identical, just centered at the wrong point. 

Ported vs Sealed response. Not a huge difference, but audible for sure. Ported open is louder accross the usable spectrum. My room has clean peak at 100hz and that showed in all subs tested.

Bucket Sub vs Dayton Sub-1200. This was most supriseing. The bucket sub is louder than the Dayton from 50hz to 100hz and equal from 50hz to 35hz where the Bucket sub gets louder again. 

A few addition images of other sub tests can be seen below

Monday, September 8, 2014

My recent adventure down Phase Lane: In Phase or Out of Phase?

Over the last month or so I have been listening to a few different set up and trying to pin point what set I wanted to build my home theater around. One set is from a well known manufacturer that that people tend to love or hate and the other from a lesser known manufacturer who has had some significant online sales of the past year or so. However, this entry isn't about a comparison between the two. This is about my experience in messing around with the phase of one of these two sets of speakers.

I found one of the pairs of speakers to be VERY muddy sounding, which when reading other professional reviews, was never a criticism of the speakers. So I wanted to start some technical tests and investigate what was going on. All of the following graphs and experience comes from an real world, untreated room. So there will be reflections and some natural room issues.

Below (graph #1) is the in room frequency response of a single of the speaker @ 1 meter. Right away the results seem to correspond to what I was hearing, a big ugly wide hump @ 150hz with everything else being acceptably flat.

Next up (in graph #2 below) was the 2.0 set up at the listening position. This is where it got really ugly, like WTF kinda ugly. This graph was unlike any that I have seen with other speakers in the same room, under essentially the same testing condition. I huge sharp dip @ 90hz; with a peak at 250hz that gradually trails off at we reach 20khz. This is were I realized I was seeing and hearing something not right. But it better explained why these speakers sounded muddy and without an detail; and absolutely not harsh or bright like they sometimes are criticized for being. I didn't know what was going on, so for nothing more than shits and giggles I switched phase on just one speaker. I remember my time in car audio and people expounding on the virtues of switching the phase on a tweeter in a component set, so I thought, maybe just maybe it will makes a difference.

This (below in graph #3) was the result. With one speaker out of phase the graph changed yet again, and this time for the better. Still a little more wavy than I would like, but finally they didn't sound so muddy and the detail and brightness came back. They sounded much more like they should have.

My first worries were it either a speaker was internally wired out of phase or that my amp was crossed some how. I triple and quadruple checked that I hadn't crossed my wires when I put on the terminal ends and that were good. Having 3 of these speakers already (used as the front 3 in a 5.1 system) I round robin tested them all. Both rotating them into position and rotating them in and out of phase and amp output A or B, the graphs always returned something very near identical. If both speakers were in the same phase, it looked and sounded like graph #2, if either speaker was out of phase with the other it looks like graph #3. 

That being the case, to the best that I can gather, this is just very weird situation that seems to be isolated to this set of speakers as they are set up in my room. At some point later I will continue my complete technical and listening review of these speakers.

Anyone got any ideas? I tried to do a little googling about phase issues, and I didn't really see anything about switching the phase on just one speaker.

Wednesday, August 6, 2014

Battle of the Harman Kardon budget brands small bookshelf speakers: Infinity Primus p143 vs. JBL Loft 30

Infinity Primus p143 vs JBL Loft 30

I have been a huge fan of the Infinity Primus line for about a while now, I've used them in 2 different home theater set ups with great results. The reputation of them online is pretty dang high and in my opinion very well deserved. At their often occurring sale prices, I don't know of anything that can beat them. With that said, at full retail, the competition if much deeper and other options should also be considered if you are willing to spend that much.

I haven't been able to find much about the JBL Loft series online, in fact they don't seem to be a product featured on the JBL web page. But they are sold at Fry's and Amazon and carry a regular price point that would have them compete for the same audience with the Infinity's.

So knowing that JBL and Infinity are both owned by Harman Kardon, both are intended as small bookshelf or surround speakers, both use 4 inch mids, and that they both retail for similar prices; currently $128.49 for the pair of JBL Loft 30 and $59.99 each for the Infinity p143 on Amazon. I thought they would make for a comparison and review.


Detailed speaker disassembly picture album

JBL: Small very basic looking almost square bookshelf speaker. Has a real xover, not just a cap on the tweeter. vinyl wood is clean if uninspired. 5 way biding posts that will accept banana plugs. Very light weight, cabinets are constructed from 1/3 inch MDF

Infinity: Significantly bigger than the JBL, similar black wood grain vinyl but almost semigloss. Nice binding posts but do not accept banana plugs without modification (or so the internet has said) Basic black grill but nicely presented and curves over the top of the speaker. Much heavier than the Loft 30. 

Winner: Infinity 


Acoustic Guitars - Arabesque - 5 Eiffel
I love this song because there are a few portions that remind me of a song from the movie Serenity. But this isn't about the greatest sci-fi movie of the last 15 years, it's about bargain speakers. In this example the Infinity p143 sounded very good, though they might be missing a little something to get some of the deeper cords and drumming against the guitar but it seems to be inline with what would be expected from a 4 inch driver. The JBL Loft 30's sounded very different, bloated mid bass give the impression of slightly deeper bass but at sacrificing a lot of detail. I also found the tweeters to be on the harsher side of things.

Adele - 21 - Rolling in The Deep
I found a pretty big difference in the vocal quality and imagine between the two speakers. The Primus' were pretty neutral sounding it sounded just like Adele should sound. Vocals weren't too forward or recessed. The Loft 30's were a whole other story. Immediately when AB testing, when switching to the Loft's its like the wind was knocked out of your ears for a second or 2. There is some small cymbal or tambourine throughout the song that just gets lost in the Lofts. I think its a combo of the in inflated midbass and something funky with the tweeter. Adeles vocals are way in the back and have a nasally quality to them.

Buffalo Springfield - Stop Children What's That Sound
This is admittedly a terrible quality MP3 that I have, we are talking Napster 1.0 128kps bad. But I wanted to play something old. Again the differences between the 2 speakers is immediately apparent. with the Lofts the vocals sound like they are coming out of a cave, they are unnaturally deep and without detail.

The Civil Wars - Barton Hallow - Billy Jean
 Love this song. And it sounded great on the p143. Imaging seemed strong and centered John Paul White's vocals. This song was a bit of an anomaly. As the sort comings of the Lofts were not as apparent for much of the song. The into is a little bloated with the Lofts, but its John Paul White's voice that gets some obvious resonances. This was even worse when listening to the title track. So while the Lofts fared better, they still were the losers. 

Katy Perry - Prism - Dark Horse
By now I've gotten a good feel for the comparison between the two speakers. The bass note in the song isn't all that deep and the p143 handle it pretty well. All the bad things about the Loft 30s shows up again. Inflated midbass that gets muddy a causes everything else to sound washed out. Vocals are recessed back and just a blog as far as imagining goes.


The JBL Loft 30's have a brighter slightly harsh tweeters, maybe a tiny bit deeper bass pretty muddy and carries into the mid range. Maybe tuned to give an artificial depth to the bass? Some noticeable resonance int he male vocal range. (Petey Pablo - part 2 - Still writing was a huge example of this). I also feel like the Infinity throws a bit wider of a sound stage and image better. Often the JBL's were just one smear of sound, where as the Infinity's had the ability to place the artist in front of you. Doing a much quicker AB testing with the Dayton b652, the Dayton best the JBLs. While there are still flaws in the b652, at the price it beats the JBL Loft 30. The comparison between the Dayton b652 and the Infinity p143 is much closer. Between the, the Infinity is the better more refined speaker that keeps it composer better particularly in the upper registers.

The frequency response graphs on the highlight the muddy bass and lower midrange on the JBL Lofts; while the Infinity Primuis p143 was incredibility flat. I would challenge anyone to find a better speaker pair under $100 new.


Above you can see the difference in listening position frequency response. The Infinity p143 are much flatter throughout the range. Darn close to +/- 3db from 100hz to 16khz. I was a little surprised that the tweeter didn't have a little farther extension but it's so much and with such a steep drop off, I'd question just exactly what you would be missing. The JBL Loft 30 has a noticeable hump from 120hz to 250hz, which is what I would attribute to the muddy sound of the midbass range.

Above is the outdoor frequency response of the Infinity Primus p143. Outside without reflections this looks pretty good to me for a sub $100 speaker

Above is the outdoor frequency response of the JBL Loft 30, again showing that midbass range hump. Though the dip in the tweeter is not seen outdoors. 

Above is the individual driver responses of the Infinity Primus p143. I looks like the mid and tweeter and crossed over around 3.5khz and the port is tuned to about 80hz.

Above is the individual driver responses of the JBL Loft 30. It seems to use a much lower and shallower cross over point around 1.75khz  

Addtional Frequency response graphs album

Wednesday, June 4, 2014

DIY ABS/PVC pipe speaker stands

I have been needing some speakers stands and wanted to try to make a DIY solution for myself. I was inspired by this example and wanted to take my own stab at it.
Overall it was a fun project, but I did run into some difficulties when trimming the ABS pipes. I have a chop saw that has adjustments on 2 different planes and no matter what I did, it always seemed to be a degree or so off. Just enough to notice if you stood the pipe on a known level surface. Thankfully that didn't seem to affect the assembly.
The stands ended up being about 3 inches to tall for the SM 65's. When I thought them out in my head I had the SM 45s on them and a slightly taller chair for seating. Total height ended up being about 35 inches when something between 29 and 32 would have been better.
They will probably be moved and used as stands for the surround speakers and will be replaced with something pre-made.
If I was going to do it again, I think I would have chosen a larger diameter pipe, these were 2 inches and I think a 3 inch pipe would be a little more stable. I also ended up putting an old 10lbs weight on the base to add some stability.

Wednesday, May 21, 2014

REVIEW: Pinnacle BD 500 - Everyone Needs a Pretty Little Black Bookshelf Speaker.

Link to speaker disassembly and graphs

Pinnacle BD 500 and Definitive Technology SM 350 

My first review of speakers that maybe considered to be of the true “budget audiophile” grade. Both of them have been found on sale recently. The Definitive Technology Studio Monitor 350's were found on Newegg on sale with a $50 manufacturer rebate which brought the total price before tax and shipping to $129.99 and the Pinnacle DB 500 which has been found on regularly over the past year for $200.00. Both speakers are of very good build quality, very nice high gloss piano black finishes on both. The Pinnacle BD 500's finish is exceptionally good with a mirror like level of gloss to it. The BD 500's do feel rather light for even their small size. And the very scientific knuckle rap gives off a slightly hollow sound, which was surprising compared to the quality of their finish. However, internally they are well stuffed with high quality dampening material. 

Acoustic Guitars - Arabesque – 5 Effiel 
Both speakers kept great pace with the fast guitar plucking, and most of the quick bass notes. The SM 350s were significantly louder in the direct AB testing. They also felt more detailed and crisp. The BD 500 were smoother and mellower; but do begin to come a live a little more as the volume increases. At lower volumes the SM 350's had a stronger center image, but the BD 500 again improved as the volume went up. 

Audioslave – Cochise 
The BD 500's were more subdued though out the range; but Chris Cornell's vocals were slightly better pronounced and were never hidden under the brighter tweeter found on the SM 350s. There was bit more presence and detail to the 50 second long intro with the SM 350's. It felt like it was filled with more excitement and anticipation. 

Bruno Mars – When I Was Your Man 
The SM 350s provided a very strong center image and the BD 500 were not far behind. I think the brighter tweeter in the SM 350 might have been a little forward and with a touch of reverb or distress or an almost echo like quality; it wasn't strong but it was there, most notable from 0:39 – 0:45. The piano sounded nice and solid across both speakers with the BD 500 maintaining its overall more mellow and less in your face sound. 

Cee-Lo Green – Closet Freak 
Now with the first test of deep bass. Neither speaker was very impressive or could reproduce the depth nor the volume of bass that this song requires. Again the brighter tweeter on the SM 350 becomes noticeable with a reoccurring bell throughout the song, but they also handled the high pitch of Cee-Lo's voice a litter better. Probably the most fun part of the song from 2:00 – 2:28 was handled better on the SM 350's. It was more fun and lively with particularly the impact of the horns was more noticeable. Both speakers handled the song well enough that enough though I've listened to this sound a million times, I picked up and heard back ground vocals that I have never noticed before.

Live – Dam at Otter Creek 
I was really pretty surprised with this song. Both speaker handled it very well. But I think this might have been a song where I would give the nod to the BD 500s. There is a lot going on in the guitar distortion and feed back in the song going on in the upper registers and the smoother more mellow tweeter of the BD 500 took the edge off a lot of it. Given that, during the AB testing the SM 350's would not have to be turned up as loud to get the same volume, so the brighter tweeter might be a bit less obvious. Both speakers handled the bass lines very well, solid drums and bass guitars all around. 

The Verdict? 

It's hard to pick a winner and I don't think there necessarily is one. They are both great speakers with their own unique characteristics. The SM 350 is a fantastic speaker at the sale price point and still great at its current retail as a discontinued line. It's very detailed, you wont miss a note anywhere; but I do think it's a little on the bright side. If you value that more detailed and intricate response this would be a good speaker to start to consider. The BD 500, a good bit smaller of a speaker lacks a little in the lower bass department and was a much more mellow and smoother sounding speaker overall; and I never encountered any harshness or fatigue while listening. It also beings to shine as the volume picks up. 

My listening room is far from ideal, but it may capture a "real life" experience better than a properly treated room would. From the graph plots both inside and outside; there is a good hump at about 150hz (I'm not sure what happened @ 3 feet, my guess its some reflection that I didn't anticipate), I didn't play with any EQing but I would imagine that if this was hump turned down a little, it may liven up the sound a little bit. Either way, the BD 500's were great speakers. 

I did feel like the SM 350's created stronger center image throughout all the testing. If given the opportunity I would recommend listing to both. For me personally, my tastes are currently leaning toward the Definitive Technology StudioMonitor 350. I felt it to be more detailed, I could “see” things happening better and can live with a slightly bright tweeter. 

I'll have a more detailed review of the much of the StudioMonitor line 350/450/45/65 in the future. 

I have used the Pinnacle BD 500 and matching center speaker as my 3.1 theater system and it has a performed great and I have really enjoyed them. It's been a tough decision and I did a lot of listening to both sets, but I'm starting to collect a few too many shiny black boxes so the Pinnacles will be on the market soon so I can work through the other pairs of speakers currently collecting dust.


Over the last months since this review, I've learned a lot and refined the technical aspects of my testing. I would love to revisit the Pinnacle BD 500 and see how it compares to some of the other speakers I've go through, and complete outdoor and single driver frequency response tests. I think the whole Pinnacle line is a great option for people. As it stands I'm running the BD 2500 II, and BD 700 II as my front 3 in my home theater with the DB 750 II for rears.


I have another pair on the way and will be updating this review in the near future. 

Thursday, April 3, 2014

Polk T15/R15 Review, Test, and Disassembly

The first budget speaker from a huge name brand that I’ve picked to disassemble and review. The T15 can regularly be found for in the $50-$60 at Best Buy which is what prompted my purchase and review. (From what I can gather the T15 and R15 are the exact same speaker, at the very least they seem to share the same tweeter. With the former being a Best Buy exclusive.)

Right off the bat it was by far the best constructed speaker I’ve seen in this price range. Thicker and a bit denser looking fiberboard than either the Dayton B653, Monoprice 8250 or the Sony B1000, the front face is nicely finished with what looks like a smooth plastic top surface, and most impressively it has at basic but real cross over (just a basic high pass and low pass filter for each driver). There is also some slight corner bracing going on. I didn’t weight them, but the T15 is heavier than the Dayton B652 and fares better on the knuckle wrap test.   

So did all these seemingly clear and obvious bonuses translate into a better sounding speaker for the money?

For a quick answer; no they didn’t. At least not to my ears and at least not for music. I’ll get to theater use a bit later.

For the ABX comparisons I used the Dayton B652, generally considered one of the best $50 pair of bookshelf speakers out there, since the price points are the same I felt they made a good match to compare to. Starting from the bottom, or the bass one might say. The Polk T15 was adequate for a small bookshelf speaker; it actually had pretty decent extension into the 80hz range. However, as music moved out of the bass range and into everything else the speakers response became very peaky in room. Part of this is just the nature of my real world testing environment (I had some oddly flat outdoor measurements throughout the midrange and up into 3khz or so). The end result was something that sounded very much like many voices were being projected through a tube. Following this, is a huge drop off in treble response starting at 2.5khz and really lasting though the rest of the audio range. This was seen in both indoor listening environment testing and outdoor testing. The Polk T15 might as well be the bastard offspring of the Monoprice 8250 and the Sony B1000.

When it comes down to it, musically these speakers are just not good performers out of the box. So I decided to use these speakers as my first attempt to make my own EQ files using REW. After a few go arounds I feel like I actually got some decent sound out of them. They became much more musical, the tube like sound was gone and I started to enjoy them as much as I have some of the step up speakers I’ve been listening to. So they do have some potential if you take the time to take some room measurements and EQ as needed.

As a basic home theater speaker, I didn’t encounter any of the obvious issues I did with music. I watched plenty of TV and movies, with The Avengers being my final test. Now they didn’t blow my socks off or anything but they were a vast improvement form the Samsung F6300’s built in speakers. If you intend to us them in this application I think you could so worse. The Polk T15 would probably be a serviceable surround speaker for any of the other similar Polk products. 

One thing I did take away as a whole, was that with a little bit of time spend working on an EQ file, these speakers really did become pretty pleasant. I don’t think it would be worthwhile to spend much time on room treatments or anything like that. But once EQ’d (a good) bit these were not bad. However out of the box I would still pick the Dayton B652 without question. 


I'm updating this review to link it with a new review of the Polk R150's; a sister speaker of the T15/R15. Im also including an outdoor response graph (@ 1m, mic placed between the tweeter and woofer. Which might help explain the huge dip, and I used a far too wide response rage on the graph that visually smooths the response far too much) that I had taken shortly after this review was made. I have learned a lot since this time and believe we can refer to the new review of the R150's to be a more accurate technical view of this group of sister speakers. I do hope to take new close mic and 1m measurement of the T15 to bring additional updates.

Emotiva B1 Review: The Wonderful World of Ribbons (AMT).

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