• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

BIC EV-15 Eviction Measurements

tomtoo

Major Contributor
Joined
Nov 20, 2019
Messages
3,607
Likes
4,514
Location
Germany
Amongst other things it depends on the enclosure volume and tuning frequency.
Yes but how big is the influence for usage?

Let's see what @Dennis Murphy has to say about it.
And let's see we not talk about a high end mod, we talk about a cheap speaker that can deliver SPL if wanted. And with a little help it can maybe sound well. Thats cool at least for me.
 

A800

Addicted to Fun and Learning
Joined
Dec 22, 2019
Messages
734
Likes
615
Yes but how big is the influence for usage?
It's quite noticeable I presume.
Maybe they didn't even calculate it.
 

KxDx

Senior Member
Joined
Nov 1, 2019
Messages
347
Likes
672
Location
Tidewater Virginia
I didn't even know you lived in the DC Metro, Dennis. For some reason I thought you were in flyover country. Too bad I don't still have my JBL CF-150's... If I did I would make the drive and drop them off at your house! :D
 

Dennis Murphy

Major Contributor
Technical Expert
Joined
Mar 17, 2020
Messages
1,071
Likes
4,535
The diameter is much too small.
You will have a shift of tuning frequency and port compression/noise at higher levels and therefore increased distortion which could have been avoided.
That's why I switched woofers for the first version. The new one runs best sealed, although it would do a lot better if the cabinet were twice as big. But I'm back to the stock woofer now in order to provide a least-cost mod option.
 
OP
JohnBooty

JohnBooty

Addicted to Fun and Learning
Forum Donor
Joined
Jul 24, 2018
Messages
632
Likes
1,555
Location
Philadelphia area
This will never be a highend speaker. But for the younger people that enjoy good sound and party at lower budget that could be great. I call it powerhifi.
I agree!

Although, believe it or not, my main interest in this speaker is not "listening at party SPLs."

I believe that large, high-output, high-sensitivity speakers are the only way to come close to reproducing the dynamic range of live, unamplified music... for example: the attack of a snare drum, etc. To do that properly, we must bring heavy artillery to the battlefield. :)

Even with their deficiencies in stock form, listening to well-recorded (ie, high dynamic range) classical music on these is a lot of fun. So a low cost mod for these that actually fixes up their frequency response would be a very very unique thing for the hobby. Even though I am sure not too many people will actually welcome these giants into their homes.

BIC EV-15
+ Mr. Murphy's improvements
+ a Crown XLS amplifier or something else that can put out a few hundred clean watts

I would call that very interesting. Far from perfect but it will do some things that would normally cost many thousands.
 
Last edited:

Severian

Active Member
Forum Donor
Joined
Jan 11, 2019
Messages
217
Likes
201
Wow. I can't believe I never saw this thread. I was chiming in with @JohnBooty when he was originally singing the praises of these speakers in an earlier thread. When @Dennis Murphy bought one and was displeased with the measurements, well, I have to admit that I've felt mildly embarrassed ever since. Little did I know there was a whole additional round of discussion about what could be done to improve these unique speakers.

I've had my pair of these for 4-5 years now. I use them in a 5.0 living room home theater setup. Ironically for their size, they remain the most elegant solution that I've ever come across for big home theater sound with minimal expense and complexity. No, they don't extend powerfully to the very bottom sub bass octave that home theater sub afficionados chase. But they get damn close, and in a small living room they produce plenty of rumble for me. And they do it on AVR power without either amp or speaker breaking a sweat. They also give the lower registers a coherence that can be easily lost with an 80hz crossover. And I greatly enjoy them for music too, even if they admittedly lack the midrange and treble clarity and resolution of better speakers. I've also used these things with a Crown amp to DJ a small wedding at thundering volumes and they sounded better than any cheapo PA setup I've heard from the typical wedding DJ.

At this point I've gone so many rounds in my head debating an upgrade path, and I just can't do it. I went so far as to buy a pair of DIYSG HTM-12 kits, and then when I thought about the hassle and expense of squeezing a pair of subs into my setup I abandoned ship and built them for a friend instead.

A while back, I upgraded mine with the cheapo GRS 5SBM1-8 midrange from Parts Express that I assume is what Dennis experimented with. I don't have a good setup for quasi-anechoic speaker measurements, so I just installed them as a drop-in upgrade without any crossover modifications. I've found them to be an excellent upgrade. The midrange sounds much smoother to me and I think the slightly lower sensitivity compared to the stock driver actually improves the tonal balance of the speaker.

And yet here I am again contemplating an upgrade or further modifications. I was thinking to myself "man, I really wish my ploy of getting Dennis Murphy to tweak the crossover hadn't gone south" and idly Googled and found this thread.

Dennis, did you ever settle on anything for the stock drivers? If so I would greatly appreciate seeing the schematic so I can take a swing at assembling it...
 

Dennis Murphy

Major Contributor
Technical Expert
Joined
Mar 17, 2020
Messages
1,071
Likes
4,535
I can't remember why I put this project aside. This was like 2.5 years ago. Maybe I'll hunt around in the furnace room and see whether this big hog is still around.
 
OP
JohnBooty

JohnBooty

Addicted to Fun and Learning
Forum Donor
Joined
Jul 24, 2018
Messages
632
Likes
1,555
Location
Philadelphia area
I still enjoy these speakers!

A fixed version would be something really, really unique for the hobby. In terms of power handling and full range-ish audio, I don't know of anything remotely like these being sold today for anywhere near the price.

More importantly, it's just nice to hear from @Dennis Murphy ! That's more important than speakers. :)
 
Last edited:

Dennis Murphy

Major Contributor
Technical Expert
Joined
Mar 17, 2020
Messages
1,071
Likes
4,535
Well, I found it, with a very complicated crossover sitting on top. Maybe that's why I stuck it in the furnace room. I'm not really seeing the attraction of these things--I doubt that the cheap drivers have all that much power handling, and they certainly don't go very low. But maybe I'll take a stab at simplifying the crossover. Perhaps I've learned some new tricks in the past 2.5 years.
 
OP
JohnBooty

JohnBooty

Addicted to Fun and Learning
Forum Donor
Joined
Jul 24, 2018
Messages
632
Likes
1,555
Location
Philadelphia area
I doubt that the cheap drivers have all that much power handling
Hi, Dennis. I'm curious what makes you say that?

I've had mine up to pretty serious levels for extended periods of time for yard parties and such, powered by a Crown XLS 1502 that puts out (a max of) legitimate few hundred watts of continuous power. I'm not sure how much power I was actually dumping into them at any point, but they've seemed really robust to me.

Maybe the large "monkey coffin" format just lets things stay relatively cool.

Or maybe in reality they were distorting more than I realized because the beer involved was distorting me.
 

Dogfinder

Member
Joined
Feb 13, 2023
Messages
14
Likes
2
Cool thread, fellas. Thanks for all of your thought and work.

I've had these speakers for 5+ years now, powering them with an Adcom GFA 5400 and an NAD reciever as a straight 2 channel (music only) in a huge room with 25 foot ceilings. Got the speakers off Craigslist for around $200 for the pair. My kids LOVE this setup (eyeroll) and when cranked it will hurt you sonically - kind of anywhere in the house, and even outside down the street. My teenage sons have walked numerous glasses off the shelf to their deaths - but just the nice ones that belonged to my mother, of course. The low end hits and provides PLENTY for today's rap stuff, but could be cleaner - particularly when playing more challenging rock stuff that I like.

The fugliness of them is a frequent conversation starter at my house... I have embraced the whole frat-house vibe, maybe that's why my love life is... well that's off topic.

I enjoy the speakers at my more human/old guy levels, but can't help thinking that they could certainly sound sweeter... Severian, are you still enjoying your GRS 5SBM1-8 replacements? Do you think going higher end could yield a better result?

I've been trolling parts-express with an itchy trigger finger...

In addition to driver replacement, do you all think dampening/stuffing the upper portion of the cab or that metal ring around the midrange could help? The stands conversation is also interesting JohnBooty, but I'm not sure that I want the coffins to be even more imposing! I'm hesitant to start messing around with crossovers without very specific guidance, considering my skill level is above-average chimp or thereabouts. I'm not opposed to putting good money after bad.

Great discussion, and thanks again!
 

mhardy6647

Grand Contributor
Joined
Dec 12, 2019
Messages
11,213
Likes
24,172
So yer after a little top end sparkle?

$_61.JPG



Just brainstorming you know? There are no wrong answers.

:cool:
 

mhardy6647

Grand Contributor
Joined
Dec 12, 2019
Messages
11,213
Likes
24,172
piezoelectric tweeters. They have been around for a long time.
They're not quite the Satan spawn that some folks think they are -- plusthey are sensitive and cheap!
That was a randomly-chosen photo of a cheap piezo array. It wasn't the best choice, because it also appears to have a more "normal" horn tweeter with, probably, a normal compression driver. It's probably atrocious.

Here's a more typical add-on piezo array.

shopping



The downfall of cheap/poor piezo implementations is (from my perspective, at least) not adding a proper crossover. Piezos behave electrically as capacitors, so they roll off 'naturally' with a crossover frequency of ca.4 kHz. They're thus usually sold as "needing no crossover" -- which is kind of true. They tend to sound harsh and "spitty" when allowed to roll off "naturally" -- putting an 8 ohm power resistor in parallel across a piezo (to mimic the resistance of a voice coil) permits a "normal" crossover to be used "upstream" of the resistor. In an add-on case, the piezo could be limited to 8 or 10 kHz. Good quality piezos (i.e., those made by CTS -- long ago sold as "Motorola" drivers) actually won't sound too bad if so employed. :)

Here's Wayne Parham's take on piezos, FWIW.

You'll find piezos in some... unusual... places. :)

s-l400.jpg


If you don't know what these rather odd looking loudspeakers are... they're rather famous if a little hard to recognize without their clothes grilles on! ;)
 

Severian

Active Member
Forum Donor
Joined
Jan 11, 2019
Messages
217
Likes
201
Cool thread, fellas. Thanks for all of your thought and work.

I've had these speakers for 5+ years now, powering them with an Adcom GFA 5400 and an NAD reciever as a straight 2 channel (music only) in a huge room with 25 foot ceilings. Got the speakers off Craigslist for around $200 for the pair. My kids LOVE this setup (eyeroll) and when cranked it will hurt you sonically - kind of anywhere in the house, and even outside down the street. My teenage sons have walked numerous glasses off the shelf to their deaths - but just the nice ones that belonged to my mother, of course. The low end hits and provides PLENTY for today's rap stuff, but could be cleaner - particularly when playing more challenging rock stuff that I like.

The fugliness of them is a frequent conversation starter at my house... I have embraced the whole frat-house vibe, maybe that's why my love life is... well that's off topic.

I enjoy the speakers at my more human/old guy levels, but can't help thinking that they could certainly sound sweeter... Severian, are you still enjoying your GRS 5SBM1-8 replacements? Do you think going higher end could yield a better result?

I've been trolling parts-express with an itchy trigger finger...

In addition to driver replacement, do you all think dampening/stuffing the upper portion of the cab or that metal ring around the midrange could help? The stands conversation is also interesting JohnBooty, but I'm not sure that I want the coffins to be even more imposing! I'm hesitant to start messing around with crossovers without very specific guidance, considering my skill level is above-average chimp or thereabouts. I'm not opposed to putting good money after bad.

Great discussion, and thanks again!
Yes, as I've said I haven't measured anything but the GRS drivers sound good to me as drop-in replacements, definitely smoother than the OEM mids. They are also slightly less sensitive than the OEM mids, which I think warms up the tonal balance in a way that pleases me. I also slightly roll off the high end with my AVR's crude EQ settings. Are there even other options out there? The OEM is closed back so I wanted to stay closed back with the replacement so as to avoid needing to improvise an separate chamber in the cabinet. I didn't look beyond Parts Express at the time, but it's the only one they had.
 

Dogfinder

Member
Joined
Feb 13, 2023
Messages
14
Likes
2
Well, I did a thing.

I took one of the pair of beasts apart, put damping in the cabinet, replaced the crossover and the body of the horn, and tilted the cabinet back a few degrees. Then I spent the next several days switching L/R (to the annoyance of the SO and amusement of my kids). Left one bone stock and the other modded to compare.

Interesting note, when I cracked it open, the cabinet has no damping except for a folded over layer of polyester batting that extends over the back of the cabinet from the top to about the bottom of the woofer. Cab bracing was non existent except for some triangular blocks between the sides and front back (and top and bottom) panels. Interesting. I thought about adding some braces, then didn't. The stock wires in the cab are THIN! I thought about replacing them, then did not. Laziness (and $) ruled the day.

Specifics:
1) 5 SF of 80mill dynamat, generic from amazon. Focused on the back panel but also some on the sealed back of the midrange and the horn body.
2) some zip stretch tape, a 40mil product for construction, has some weight to it, used for gaskets around the drivers and some on the horn body.
3) Sonic barrier from Parts Express. 3/4 inch, freaking expensive, 1 sheet
4) Acoustistuff from Parts Express, 1 pound
5) Crossover: Uxcell 180W 3-way from amazon. 2 for $26... more on that.
6) 1.5" rubber feet at the front of the base, to give me a tilt.
7) Goldwood 85/8 midrange driver replacement
8) Old bath mat glued to the top and bottom. What the hell.

Thoughts after infinite L/R balance switching and making funny faces:
1) My soldering sucks. But I think it was functional. Getting better.
3) First audio impression: This sucks. But, after letting the midrange break in for 2 days, it opened up, A LOT. The whole thing is more midrange forward now.
4) Everything sounds much more controlled. No more small echoes, much better clarity.
5) Seems to have lost some overall sensitivity, makes sense with all the crap in the box, I guess. Except for the midrange - the new Goldwood's 96db sensitivity is legit.
6) The sucker is heavier than hell now. I could carry the unmoved box with some groaning. Now I ask for help on the modded one.
7) Bass is noticeably reduced. At first I had the acoustistuff low in the box, and I noticed it was blocking the ports. I cracked it back open (my new gaskets make that a pain now), hot glued the new fill higher on the back wall behind the drivers, and as far as I could tell, it didn't make much of a difference. Not sure if the reduced bass is a crossover thing, or all the damping, or the new tilt resulting in floor bounce phase-cancel stuff. Or maybe the new midrange just dominating everything else.
8) The tilt looks really cool. Amazing what it does to fight the big, uninteresting, black monkey coffin rectangle factor. It might also help with the midrange audibility at standing height.

Overall, qualitatively (to my ears) the speaker is improved, much sweeter, more discernible vocals, but the loss of low end is disturbing. The changes are not night and day. The unmodded speaker is near a corner, so I am sure the room effects are not helping. Too many variables! Lost a driver screw along the way. Lowes has #8 SS sheet metal screws, pan-head that seem to match perfectly.

Next Steps:
1) I plan to do the exact mod on the other cab, but leave the crossover intact. I will see how the new, cheap crossover affects the bass output, and overall sound. Pretty sure the second one will take 1/2 the time. Less, because of leaving the original crossover.
2) I am recovering the screens with some fender oxblood amp grill cloth. Trying to get a little more sheer to show a hint of the red woofer, add interest factor, maybe a little more acoustically transparent at the upper end. The fabric from Mojotone drops tomorrow.

All in all, a fun project dumping $250 into speakers I paid $200 for the pair on Craigslist. For $450 could I have gotten something "nicer?" Yep. I saw some Mach ones in that price range recently, and even some AR 90s that tickled my fancy (big, interesting-looking speakers). But, I am making the Bics my own, and enjoying the process.

A few photos from the process. You can see the old vs new crossover (new in the bag).
 

Attachments

  • IMG_9338.jpg
    IMG_9338.jpg
    370.3 KB · Views: 54
  • 69964686657__9C49701A-9061-48EA-B36C-8FBFFCC3E1EB.jpg
    69964686657__9C49701A-9061-48EA-B36C-8FBFFCC3E1EB.jpg
    541.6 KB · Views: 43
  • IMG_9334.jpg
    IMG_9334.jpg
    268 KB · Views: 45
  • IMG_9335.jpg
    IMG_9335.jpg
    606.5 KB · Views: 42
  • IMG_9340.jpg
    IMG_9340.jpg
    182.5 KB · Views: 45
  • IMG_9343.jpg
    IMG_9343.jpg
    231.8 KB · Views: 47

Severian

Active Member
Forum Donor
Joined
Jan 11, 2019
Messages
217
Likes
201
Interesting project! However, I'm going to guess that the crossover you used is a step down from the originals. I see the crossover points listed as 850 Hz and 4000 Hz. I've never seen the stock crossover points listed, but the woofer is probably crossed at more like 300Hz. The stock crossover also probably pads the tweeter a bit more than the crossover you installed, which may explain why you are hearing a brighter tonal balance.

I once experimented with installing a cheapo 3-way crossover in some early 90s Sony three-ways and that was pretty much what I found: no tweeter padding made for a bright sound, and there was not even a gesture in the way of baffle step compensation.
 
Top Bottom