Finished AV1... Mixed Feelings... did I do something wrong?

Discussion in 'Archived Threads 2001-2004' started by Andrew Lin, Jun 25, 2002.

  1. Andrew Lin

    Andrew Lin Extra

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    So today I finished up glueing together my AV1 enclosures with the Black Hole material and Cross overs in place inside. I was anxious to try them out so I put in the drivers and connected them all together and put them against my current HT speakers the Polk Audio RT35i's.

    Listening to them both with some trumpet concertos as well as some Dave Matthews, my feelings are kind of mixed. First it seems that the impedence of the AV1s are some what higher than the Polks, that is I have to turn up the volume higher on the reciever in order to get the same volumne output from the speakers.

    That aside, it seems that the AV1s seem very smooth, however it seems to lose accuracy in that respect. The RT35is thus seem brighter and more accurate. When listening to this, it shocked me as the AV1s are suppose to out perform the RT35i's with out breaking a sweat.

    So this leads me to think...did I do something wrong in constructing the speakers? I followed the instructions using 3/4" MDF tuning the box to 55hz (I believe, I'm to lazy to go down and check the specs from GR) I put in the Black Hole material on the two sides as well as the top of the inside of the enclosure. The cross overs were built correctly, I'm fairly confident in my soldering job.

    Do these speakers need time to be broken in? Does this description sound correct for these speakers? Am I just crazy and I have no idea what to listen for in a good speaker? (
     
  2. Since I have never built those speakers, I can only offer general possibilities

    1) do you have adiquate space behind the speaker?
    2) are the drivers sealed to the enclosures with something like weather stripping?
    3) are the speakers in phase?
    4) are the drivers wired up properly?

    if you are sure about all of these (especially #4), then I am out of solutions=(
     
  3. Andrew Lin

    Andrew Lin Extra

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    Well Ive been only testing one speaker aganist one speaker b/c I only have one AV1 built. As far as I know the speaker is wired correctly, I mean it sounds fine, just not as good ias I thought it was, there is space behind the speaker as it is rear ported. I also have installed the stripping that goes behind the speakers aganist the MDF.

    Any other suggestions, espically those who have built these before??
    Thanks!!
     
  4. Brian Bunge

    Brian Bunge Producer

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    Andrew,

    First of all, yes they need to be broken in first. Also, I'm not sure you can accurately compare one speaker to another. At least I've never tried it. I compare them as a pair and listen for imagining and soundstage as well as accuracy.

    I would highly expect the Polks to sound brighter as they have metal dome tweeters. The GR T1 is very accurate and smooth and has been compared favorably to some of the much more expensive Scan-Speak units.

    You may also want to try to add some polyfil stuffing behind the woofer to further damp internal reflections.

    Brian
     
  5. Patrick Sun

    Patrick Sun Moderator
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    Are the drivers connected properly (check for the polarity of each driver w/r/t crossover diagram). If not, you could have a hole in the response around the crossover frequency region.
     
  6. Brian Bunge

    Brian Bunge Producer

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    Oh yeah, that reminds me of something else. The tweeter doesn't seem to have the polarity marked on leads. The larger lead is the positive and the smaller is the negative. Double check this.

    Brian
     
  7. jeff lam

    jeff lam Screenwriter

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    Also make sure your x-over is not shorted. Those inductor leads are quite long when they come from Danny. IF you didn't trim them back they may be shorting to another connection. This was a problem with several people from the AA forum. If you think all is good, finish the second speaker and compair the two pairs, you will find that the imaging of the AV1's will be much better than the polks. At least that's the first thing I noticed with my AV1's (the imaging stood out right away). Anyway, the sensitivity of the AV1's are lower than most comercial speakers which expalins the lower volume, that's normal. Finish both speakers, give about 40hrs to break in and then post your results. I think you will be quite pleased.
     
  8. Andrew Lin

    Andrew Lin Extra

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    Wow thanks guys for all your support!

    I'm pretty sure that the cross overs are not shorting out as that happened to me before I started the enclosures when I was testing out just the crossovers. As for the filling, shouldn't the black hole material be enough filling or do I also need the polyfil behind the woofer?( and where would I get some?) And I also checked the leads on the tweeter and they are connected correctly.

    I just finished glueing up the second speaker enclosure so I will be shortly putting the driver in them. I will update on my reflections of the speakers.

    Once again.. Thanks for all your help!
     
  9. Brian Bunge

    Brian Bunge Producer

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    Andrew,

    IIRC, Danny said that adding a little polyfil directly behind the woofer should help even more. Just don't block the port.

    Brian
     
  10. Martice

    Martice Screenwriter

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    It took a while for my AV1+'s to really start shinning. I have the black hole 5 in mine and I also put polyfill inside the cabinet behind the woofers. The speakers are wonderful and clearly the best investment I've made along with the Sony TA-P9000es audio switcher.
     
  11. CarlDais

    CarlDais Stunt Coordinator

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    Best of luck to you in your AV-1 construction,
    as well as comparing and contrasting the two
    different speakers.

    More to the point of Comparing & contrasting
    single speakers. This is not way out in left
    field. In Fact that is exactly what was done
    at the Canadian National Research facilty when
    evaluating speakers.Among many other rigorous tests.
    I went on a tour of the
    Revel/JBL/Madrigal speaker facilty in Southern
    California. Mr O'Toole, who was at the NRC,
    mentioned this as one of their tests. I also
    remember reading that Dynaudio does this as well.
    Mono sources can highlight Timbre abnormalities
    much more easily.
    Mono listening of test tones such as Pink noise
    will really call into question Freq Response
    irregularities as well as off axis problems.
    Seems that two speakers can mask some warts.
    But yes ultimately a stereo pair is evaluated
    as a pair.
    I have evaluated speakers myself by listening
    to a Mono recording on one speaker then shifting
    the balance to the other speaker. You aren't as
    distracted by the Hi-fi stuff like pinpoint images,
    Soundstage width or depth. This mono comparison
    with the same pair works well to compare two amps.
    J Gordon Holt may moons ago would employ this timbre
    evaluation of a speaker...."if it can't get the mid-
    range right, who cares about the other stuff". And
    many moons ago this notion of Stereo VS mono was the
    stuff of great debates....phase interactions of the
    two speakers was blamed for all sorts of deminished
    High Fidelity Sound Reproduction....
    ...or so many claimed.

    Once again best of luck to you in your evaluations.
    Blind level matched comnparisons will often paint
    the test in a different light.
     
  12. Danny Richie

    Danny Richie Stunt Coordinator

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    Andrew,

    First off I personally never even give a new design or a new speaker a listen until after I have burned it in for about 40 to 50 hours.

    A lot will change about the A/V-1's after burning them in. Bass response will be fuller bodied and deeper. Highs will smooth out a little and have clearer detail.

    Keep in mind when A/B-ing speakers to match the output levels. In most cases if one has higher sensitivity than another most will tend to perceive the higher output level as having a better sound.

    Also don't confuse brightness in the higher frequencies with accuracy or detail. A speaker with poor balance having the higher frequencies tipped up (higher sensitivity level) can give the misconception of greater detail. Listen to some isolated acoustic instruments. The speaker with greater clarity and detail will be easy to distinguish.

    While mono listening is very useful in distinguishing some aspects it will not give you much of an impression of how a pair will perform. The effects of minimal phase shifts, driver time alignment, and preservation of the signal will become obvious only when listing to a pair of speakers. It is then that those things will become aperient in imaging, sound stage, depth, and placement.

    I look forward to hearing the details of your comparisons after burn in.

    Enjoy,
    Danny Richie
     
  13. Robert_Gaither

    Robert_Gaither Screenwriter

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    Andrew, since you didn't state what's powering the speakers the other thing that might need to be taken into account is the Polks if I remember correctly are 8 ohms and AV1s are 4 ohms which means the amp/AVR powering them might lack the current delivering capabilities to take advantage of the newer speakers (good speakers sometime reveal a weak link better as well).
     
  14. Brian Bunge

    Brian Bunge Producer

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    Robert,

    The A/V-1's are 8 ohms as well. The A/V-1+'s are 4 ohms.

    Brian
     
  15. I already erased your name to the last person who posted on a message for the whole list of messages that I am showing.....so I had to finish the job and post here too=)


    Alright...I now have my name on the top 5 messages!!!...that is good luck or something right?

    (40 minutes and counting till D-Day!!!)
     
  16. Kevin Deacon

    Kevin Deacon Second Unit

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    I have about 5 more coats of varnish to go before my AV1's are complete. I went home last night with good intentions of adding another varnish coat when all of a sudden out came the drivers, crossovers and stuffing. I just couldn't stand it anymore and had to have a listen. I am very impressed with what I heard. I listened to the first disc of "The Wall" and couldn't believe the bass that these small speakers put out. Granted, you need a subwoofer to hit the low notes, but the AV1's go lower than my 6.5" MTM's. Maybe I have a problem with the MTM's.

    Great little speaker.
     
  17. Brian Bunge

    Brian Bunge Producer

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    Kevin,

    5 coats! You must be going for a high gloss finish. And I thought 4 coats of a satin poly was overkill...

    I've said before that in a small room I could live without a subwoofer for a music only system using the A/V-1's.

    Brian
     
  18. Kevin Deacon

    Kevin Deacon Second Unit

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    I'm using Barley's gel varnish and the application is wipe on and wipe off, so it takes a while to build this stuff up. No sanding between coats (exectly why I chose this stuff) is nice.

    I sure wish I had known about dye instead of stain. The only type of stain that I could get a particular color in was Minwax water based stain. I applied the stuff in the Phoenix heat (110 degrees) and it was very difficult to get even. Water based stain and heat (dry heat) don't mix. I should have gone indoors to apply it, oh well live and learn. I am applying the varnish indoors where it's nice and cool and not too smelly either.
     
  19. Brian Bunge

    Brian Bunge Producer

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    Kevin,

    The wipe on poly I use only requires sanding lightly with 600 grit paper between the 2nd and 3rd coats. Awesome stuff! I just wish it was cheaper! It's around $8 for a pint.

    Brian
     
  20. Kevin Deacon

    Kevin Deacon Second Unit

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    Brian,

    What is the brand name and where do you get it? I'm always up for something new, and if it only takes 3 to 4 coats I'm definately interested, thanks.

    Also, if you wouldn't mind, I'm trying to perfect my veneering skills and was wondering if there is a better technique. Here's what I do:

    Apply veneer with cement and j-roll with alot of pressure. Once in a while the roller slips off the edge and breaks the veneer. Sometimes the wood splinters well into the edge and I get a defect. Is there a better way, if not is there a filler product that will accept dye/stain and become un-noticeable. Uh, Oh, a light bulb just went on, now that I am writing this I just thought, "What if I trim the edges before rolling with alot of pressure. If I slip off the edge there won't be anything to bend and break". Maybe this is the answer.

    Once an edge is trimmed (with a router and straight bit) I use a random orbit sander to get the just-routed edges flush. This seems to work well except for the minor defects as noted above.

    Am I using the right techniques and do you have anything to add? Thanks for your help.
     

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